gestalt theory case study

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings
• My Bibliography
• Collections
• Citation manager

Save citation to file

Email citation, add to collections.

• Create a new collection
• Add to an existing collection

Add to My Bibliography

Your saved search, create a file for external citation management software, your rss feed.

• Search in PubMed
• Search in NLM Catalog
• Add to Search

Gestalt Therapy Applied: A Case Study with an Inpatient Diagnosed with Substance Use and Bipolar Disorders

Affiliation.

• 1 Private Practice, Tel Aviv, Israel.
• PMID: 27098212
• DOI: 10.1002/cpp.2016

Aim: The aim of the present paper is to open the discourse regarding the unmet needs of specific patients, especially those with substance use disorder and/or personality disorder where 'multimorbidities', and/or 'overdiagnosis' and/or 'diagnosis overlap' are frequent. An additional aim is to review the main therapeutic purpose and concepts of Gestalt therapy which might be appropriate in the treatment of these patients often characterized by their difficulties in being aware and in contact in the 'here and now'.

Methods: I first start with an overview of Gestalt therapy concepts. Then, I illustrate Gestalt's 'here and now' and awareness concepts applied during 18 sessions with an inpatient diagnosed with substance use and bipolar disorders. In addition, the patient had to face an open criminal charge, was regarded as having an antisocial personality disorder and argued suffering from post-traumatic stress disorder.

Results: After this two-month therapy period, the patient entered for the first time a daily rehabilitation program in the community, where he was doing well (this after a few prior hospitalizations). The awareness development in the 'here and now' through which different contact styles and cycles of experiences are experienced is a process that allowed the patient to start experiencing contact with himself, his true needs and his environment. This contributed to his well-being improvement, led and supported his rehabilitation and reinsertion within the society and decrease his relapses, either with drugs or criminal activities. Copyright © 2016 John Wiley & Sons, Ltd.

Key practitioner message: People with substance use disorder (where 'multimorbidities', 'overdiagnosis' or 'diagnosis overlap' are frequent), people with personality disorder(s) or people who have difficulties in defining what really disturbs them are the same people who could benefit of GT encouraging awareness and contact development in the 'here and now'. Gestalt therapy should not be regarded as a practitioner's toolbox but as a therapeutic process allowing awareness and I-boundaries development in the 'here and now' through authentic and genuine relationships. The therapist's awareness and contact with themselves and their environment are reflected in the therapist's relaxed but awake and aware state of mind as well as their wise, spontaneous and mindful approach.

Keywords: Awareness; Bipolar Disorder BP; Gestalt Therapy; Personality Disorder PD; Substance Use Disorder SUD; Therapeutic Relationship.

Copyright © 2016 John Wiley & Sons, Ltd.

PubMed Disclaimer

Similar articles

• Therapeutic community treatment for substance abusers with antisocial personality disorder. Messina NP, Wish ED, Nemes S. Messina NP, et al. J Subst Abuse Treat. 1999 Jul-Sep;17(1-2):121-8. doi: 10.1016/s0740-5472(98)00066-x. J Subst Abuse Treat. 1999. PMID: 10435260 Clinical Trial.
• [Substance use, affective problems and personality traits: test of two association models]. Chakroun N, Doron J, Swendsen J. Chakroun N, et al. Encephale. 2004 Nov-Dec;30(6):564-9. doi: 10.1016/s0013-7006(04)95471-1. Encephale. 2004. PMID: 15738859 French.
• Management of comorbid bipolar disorder and substance abuse. Vornik LA, Brown ES. Vornik LA, et al. J Clin Psychiatry. 2006;67 Suppl 7:24-30. J Clin Psychiatry. 2006. PMID: 16961421 Review.
• Update on bipolar disorder and substance abuse: recent findings and treatment strategies. Ostacher MJ, Sachs GS. Ostacher MJ, et al. J Clin Psychiatry. 2006 Sep;67(9):e10. doi: 10.4088/jcp.0906e10. J Clin Psychiatry. 2006. PMID: 17081077
• Bipolar disorder and substance abuse. Levin FR, Hennessy G. Levin FR, et al. Biol Psychiatry. 2004 Nov 15;56(10):738-48. doi: 10.1016/j.biopsych.2004.05.008. Biol Psychiatry. 2004. PMID: 15556118 Review.

Publication types

• Search in MeSH

Related information

• PubChem Compound (MeSH Keyword)

LinkOut - more resources

Full text sources, other literature sources.

• scite Smart Citations
• MedlinePlus Consumer Health Information
• MedlinePlus Health Information

Miscellaneous

• NCI CPTAC Assay Portal

• Citation Manager

NCBI Literature Resources

MeSH PMC Bookshelf Disclaimer

The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Unauthorized use of these marks is strictly prohibited.

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• HHS Author Manuscripts

A Century of Gestalt Psychology in Visual Perception I. Perceptual Grouping and Figure-Ground Organization

Johan wagemans.

1 Laboratory of Experimental Psychology, University of Leuven (KU Leuven), Belgium and Institute of Advanced Studies (IEA-Paris), France

James H. Elder

2 Centre for Vision Research, York University, Canada

Michael Kubovy

3 Department of Psychology, University of Virginia, U.S.A.

Stephen E. Palmer

4 Department of Psychology, University of California at Berkeley, U.S.A.

Mary A. Peterson

5 Department of Psychology and Cognitive Science Program, University of Arizona, U.S.A.

Manish Singh

6 Department of Psychology and Center for Cognitive Science, Rutgers University - New Brunswick, U.S.A.

Rüdiger von der Heydt

7 Mind/Brain Institute, Johns Hopkins University, U.S.A.

In 1912, Max Wertheimer published his paper on phi motion, widely recognized as the start of Gestalt psychology. Because of its continued relevance in modern psychology, this centennial anniversary is an excellent opportunity to take stock of what Gestalt psychology has offered and how it has changed since its inception. We first introduce the key findings and ideas in the Berlin school of Gestalt psychology, and then briefly sketch its development, rise, and fall. Next, we discuss its empirical and conceptual problems, and indicate how they are addressed in contemporary research on perceptual grouping and figure-ground organization. In particular, we review the principles of grouping, both classical (e.g., proximity, similarity, common fate, good continuation, closure, symmetry, parallelism) and new (e.g., synchrony, common region, element and uniform connectedness), and their role in contour integration and completion. We then review classic and new image-based principles of figure-ground organization, how it is influenced by past experience and attention, and how it relates to shape and depth perception. After an integrated review of the neural mechanisms involved in contour grouping, border-ownership, and figure-ground perception, we conclude by evaluating what modern vision science has offered compared to traditional Gestalt psychology, whether we can speak of a Gestalt revival, and where the remaining limitations and challenges lie. A better integration of this research tradition with the rest of vision science requires further progress regarding the conceptual and theoretical foundations of the Gestalt approach, which will be the focus of a second review paper.

1 Introduction

Exactly 100 years ago Wertheimer (1912) published his paper on phi motion—perception of pure motion, without object motion—which many consider to be the beginning of Gestalt psychology as an important school of thought. The present status of Gestalt psychology is ambiguous. On the one hand, many psychologists believe that the Gestalt school died with its founding fathers in the 1940s or after some devastating empirical findings regarding electrical field theory in the 1950s, or that it declined because of fundamental limitations that blocked further progress, while stronger theoretical and experimental frameworks arose in the 1960s and 1970s that have dominated the field ever since (e.g., cognitive science, neuroscience). On the other hand, almost all psychology textbooks still contain a Gestalt-like chapter on perceptual organization (although often poorly connected to the other chapters), and new empirical papers on Gestalt phenomena appear with increasing frequency.

We are convinced that Gestalt psychology is still relevant to current psychology in several ways. First, questions regarding the emergence of structure in perceptual experience and the subjective nature of phenomenal awareness (e.g., visual illusions, perceptual switching, context effects) continue to inspire contemporary scientific research, using methods and tools that were not at the Gestaltists’ disposal. Second, the revolutionary ideas of the Gestalt movement continue to challenge some of the fundamental assumptions of mainstream vision science and cognitive neuroscience (e.g., elementary building blocks, channels, modules, information-processing stages). Much progress has been made in the field of nonlinear dynamical systems, both theoretically and empirically (e.g., techniques to measure and analyze cortical dynamics), progress that allows modern vision scientists to surpass some of the limitations in old-school Gestalt psychology as well as those in mainstream vision research.

The centennial anniversary of Gestalt psychology is therefore an excellent opportunity to take stock of what we have discovered about core Gestalt phenomena of perceptual organization and how our understanding of the underlying mechanisms has evolved since Wertheimer’s seminal contribution. Due to this review’s scope, we divide it in two parts: This paper deals with perceptual grouping and figure-ground organization, whereas the second covers modern developments regarding the general conceptual and theoretical frameworks that underlie Gestalt ideas (e.g., holism, emergence, dynamics, simplicity). In Table 1 , we provide an overview of the topics covered in the first review paper, together with the section headings, the questions or issues being raised, and some of the answers provided. One of the aims of our review is to remove the many misunderstandings surrounding Gestalt psychology, which are listed separately in Table 2 , along with a more balanced view on the actual state of affairs.

Overview of the paper with section numbers and headings, questions and issues raised, and answers provided

Common misunderstandings about Gestalt psychology

To put these two reviews in perspective, we first introduce the key findings and ideas of the founders of Gestalt psychology, along with a brief sketch of its further development, rise, and fall (for an extensive treatment, see Ash, 1995 ). The historical section ends with a discussion of Gestalt psychology’s empirical and conceptual problems and an indication of how these limitations are being addressed in current research. We then review current research on perceptual grouping and figure-ground organization in more detail in the remaining sections. We focus on these two topics because they were the most important ones in the Gestalt tradition of perceptual organization and still are today, even for vision in general.

2 A Brief History of Gestalt Psychology

This section addresses four questions regarding Gestalt psychology: (1) How did it start? (2) What does it stand for? (3) How did it evolve? (4) Where does it stand now?

2.1 The Emergence of Gestalt Psychology

What Max Wertheimer discovered in 1912 was called phi motion, a special case of apparent motion. (For an excellent discussion of its historical importance, see Sekuler, 1996 ; for a demonstration of the phenomenon and for a review of its misrepresentation in later sources, see Steinman, Pizlo, & Pizlo, 2000 .) According to the conventional view of apparent motion, we see an object at several successive positions and motion is then “added” subjectively. If this were correct, then an object would have to be seen as moving, and at least two positions—the starting and end points—would be required to produce seen motion. Neither of these conditions held in the case of phi motion. In the key experiment, a white strip was placed on a dark background in each of two slits in the wheel of a tachistoscope, and the rotation speed was adjusted to vary the time required for the light to pass from one slit to the next (i.e., the interval between the two). Above a certain threshold value (~200 ms), observers saw the two lines in succession. With much shorter intervals (~30 ms), the two lines appeared to flash simultaneously. At the optimal stage (~60 ms), observers perceived a motion that could not be distinguished from real motion. When the interval was decreased slightly below 60 ms, after repeated exposures, observers perceived motion without a moving object—that is, pure phenomenal or phi motion. Although only three observers were tested, “the characteristic phenomena appeared in every case unequivocally, spontaneously, and compellingly” ( Wertheimer 1912/1961 , p. 1042). In the same paper, Wertheimer proposed a physiological model described in terms of a short circuit and a flooding back of the current flow (“transverse functions of a special kind;” Wertheimer, 1912/1961 , p. 1085), which produced what he called “a unitary continuous whole-process” ( Wertheimer, 1912/1961 , p. 1087). He then extended this theory to the psychology of pure simultaneity (for the perception of form or shape) and of pure succession (for the perception of rhythm or melody). These extensions were decisive for the emergence of Gestalt theory.

2.2 Essentials of Gestalt Theory

The phi phenomenon was the perception of a pure process, a transition that could not be composed from more primitive percepts of a single object at two locations. In other words, perceived motion was not added subjectively after the sensory registration of two spatiotemporal events but had its own phenomenological characteristics and ontological status. From this phenomenon, Wertheimer concluded that structured wholes or Gestalten, rather than sensations, are the primary units of mental life. This was the key idea of the new and revolutionary Gestalt theory, developed by Wertheimer and his colleagues in Berlin. An overview of how the Berlin school of Gestalt psychology distinguished itself from the dominant view of structuralism and empiricism, as well as of related Gestalt schools is given in Table 3 .

Key claims by the Berlin school of Gestalt psychology in opposition to other schools

The notion of “Gestalt” had already been introduced into psychology by Christian von Ehrenfels in his essay “On Gestalt qualities” ( 1890 ). Based on the observation that humans can recognize two melodies as identical even when no two corresponding notes in them have the same frequency, von Ehrenfels argued that these forms must possess a “Gestalt quality”—a characteristic that is immediately given, along with the elementary sensations that serve as its foundation, a characteristic that is dependent on its constituent objects but rises above them. For von Ehrenfels, Gestalt qualities rest uni-directionally on sense data: Wholes are more than the sums of their parts, but the parts are the foundation (“Grundlage”) of the whole. In contrast, Wertheimer claimed that functional relations determine what will appear as the whole and what will appear as parts (i.e., reciprocal dependency). Often the whole is grasped even before the individual parts enter consciousness. The contents of our awareness are by and large not additive but possess a characteristic coherence. They are structures that are segregated from the background, often with an inner center, to which the other parts are related hierarchically. Such structures or “Gestalten” are different from the sum of the parts. They arise from continuous global processes in the brain, rather than combinations of elementary excitations.

With this step, Wertheimer separated himself from the Graz school of Gestalt psychology, represented by Alexius Meinong, Christian von Ehrenfels, and Vittorio Benussi. They maintained a distinction between sensation and perception, the latter produced on the basis of the former. The Berlin school, represented by Max Wertheimer, Kurt Koffka, and Wolfgang Köhler, considered a Gestalt as a whole in itself, not founded on any more elementary objects. In their view, perception was not the product of sensations but it arose through dynamic physical processes in the brain. As a result, the Berlin school also rejected stage theories of perception proposed by the Leipzig school, represented by Felix Krüger and Friedrich Sander, in which the gradual emergence of Gestalten (“Aktualgenese” or “microgenesis”) played a central role. Although the Berlin theorists adhered to a nonmechanistic theory of causation and did not analyze the processes into stages, they did believe that the functional relations in the emergence of Gestalts could be specified by laws of perceptual organization.

2.3 Further Development, Rise, and Fall of Gestalt Psychology

Two major developments are generally considered as highlights in the history of Gestalt psychology: Köhler’s discussion of “physical Gestalten” (1920) and Wertheimer’s proposal of “Gestalt laws of perceptual organization” ( 1923 ). Köhler (1920) extended the Gestalt concept from perception and behavior to the physical world, thus attempting to unify holism (i.e., the doctrine stressing the importance of the whole) and natural science. He proposed to treat the neurophysiological processes underlying Gestalt phenomena in terms of the physics of field continua rather than that of particles or point-masses. In such continuous field systems, which he called strong Gestalten, the mutual dependence among the parts is so great that no displacement or change of state can occur without influencing all the other parts of the system. Köhler showed that stationary electric currents, heat currents, and all phenomena of flow are strong Gestalten in this sense. These he distinguished from what he called weak Gestalten, which do not show this mutual interdependence.

In addition, Köhler tried to construct a specific testable theory of brain processes that could account for perceived Gestalten in vision. He thought of visual Gestalten as the result of an integrated process in what he referred to as “the entire optical sector,” including retina, optical tract, and cortical areas, as well as transverse functional connections among conducting nerve fibers (i.e., a recurrent neural network in modern terms). He proposed an electrical field theory, in which “the lines of flow are free to follow different paths within the homogeneous conducting system, and the place where a given line of flow will end in the central field is determined in every case by the conditions in the system as a whole” ( Köhler, 1920/1938 , p. 50). In modern terms, Köhler had described the visual system as a self-organizing physical system.

These ideas led Köhler to postulate a psychophysical isomorphism between the psychological reality and the brain events underlying it: “actual consciousness resembles in each case the real structural properties of the corresponding psycho-physiological process” ( Köhler, 1920/1938 , p. 38). By this he meant functional instead of geometrical similarity indicating that brain processes do not take the form of the perceived objects themselves. In addition, he insisted that such a view does not prescribe complete homogeneity of the cortex but is perfectly compatible with functional articulation. Experiments to establish the postulated connections between experienced and physical Gestalten in the brain were at the time nearly impossible to conduct, but decades later, Köhler attempted to do so (see below).

Around the same time, Max Wertheimer further developed his Gestalt epistemology and outlined the research practice of experimental phenomenology that was based on it. He first stated the principles publically in a manifesto published in Volume 1 of Psychologische Forschung in 1922. Wertheimer called for descriptions of conscious experience in terms of the units people naturally perceive, rather than the artificial ones imposed by standard scientific methods. By assuming that conscious experience is composed of units analogous to physical point-masses or chemical elements, psychologists constrain themselves to a piecemeal inquiry into the contents of consciousness, building up higher entities from constituent elements, using associative connections. In fact, such and-summations (“Und-Summe”), as Wertheimer called them, appear “only rarely, only under certain characteristic conditions, only within very narrow limits, and perhaps never more than approximately” ( Wertheimer 1922/1938 , p. 13). Rather, what is given in experience “is itself in varying degrees ‘structured’ (‘gestaltet’), it consists of more or less definitely structured wholes and whole-processes with their whole-properties and laws, characteristic whole-tendencies and whole-determinations of parts” ( Wertheimer 1922/1938 , p. 14). The perceptual field does not appear to us as a collection of disjointed sensations, but possesses a particular organization of spontaneously combined and segregated objects.

In 1923, Wertheimer published a follow-up paper, which was an attempt to elucidate the fundamental principles of that organization. The most general principle was the so-called law of Prägnanz, stating, in its most general sense, that the perceptual field and objects within it will take on the simplest and most encompassing (“ausgezeichnet”) structure permitted by the given conditions. For Köhler (1920) , this tendency towards the Prägnanz of the Gestalt was just another example that phenomenal Gestalten were like physical Gestalten: As shown by Maxwell and Planck, all processes in physical systems, left to themselves, show a tendency to achieve the maximal level of stability (homogeneity, simplicity, symmetry) with the minimum expenditure of energy allowed by the prevailing conditions. More specific principles that determine perceptual organization according to Wertheimer were proximity, similarity, uniform density, common fate, direction, good continuation and “whole properties” (or “Ganzeigenschaften”) such as closure, equilibrium, and symmetry.

Empirical work on these principles existed before Wertheimer’s landmark paper (for a recent review, see Vezzani, Marino, & Giora, 2012 ), but now the general claim that perceptual experience is organized was turned into a complex open-ended research program aimed at the discovery of the laws or principles governing perceptual organization in both its static and dynamic aspects. It is this research program that Wertheimer, Koffka and Köhler started to work on with their students, once they had acquired professorships at major universities in Germany in the 1920s and 1930s. We cannot cover this flourishing period of the Berlin school of Gestalt psychology extensively here, but a few highlights that deserve mentioning in passing are studies by Kurt Gottschaldt on embedded figures ( 1926 ), Joseph Ternus on phenomenal identity ( 1926 ), Karl Duncker on induced motion (1929), Wolfgang Metzger on a homogeneous Ganzfeld ( 1930 ) and motion in depth ( 1934 ). In the meantime, Gestalt thinking also affected research on other sense modalities (e.g., binaural hearing by Erich von Hornbostel), on learning and memory (e.g., Otto von Lauenstein and Hedwig von Restorff), and on thought (e.g., Karl Duncker). Later, Gestalt theory was also applied to action and emotion (by Kurt Lewin), to neuropathology and the organism as a whole (by Adhemar Gelb and Kurt Goldstein), and to film theory and aesthetics (by Rudolf Arnheim). This period marked the high point but not the end of Gestalt psychology’s theoretical development, its research productivity, and its impact on German science and culture.

Around this time, Gestalt theory also started to have some impact on research in the U.S., mainly owing to Wolfgang Köhler and Kurt Koffka (see King & Wertheimer, 2005 , Chapter 10). For instance, Koffka’s (1935) notion of vector fields inspired some interesting empirical work published in the American Journal of Psychology ( Brown & Voth, 1937 ; Orbison, 1939 ). Reviews of Gestalt psychology appeared in Psychological Review on a regular basis (e.g., Helson, 1933 ; Hsiao, 1928 ), a comprehensive book on state-of-the-art Gestalt psychology was published as early as 1935 ( Hartmann, 1935 ), and three years later Ellis’s (1938) influential collection of translated excerpts of core Gestalt readings made some of the original sources accessible to a non-German-speaking audience. Already in 1922, at Robert Ogden’s invitation, Koffka had published a full account of the Gestalt view on perception in Psychological Bulletin.

At first sight, Gestalt theory seemed to develop rather consistently, from studying the fundamental laws of psychology first under the simplest conditions, in elementary problems of perception, before including complex sets of conditions, and turning to other domains such as memory, thinking, emotion, aesthetics, and so forth. At the same time, however, the findings obtained did not always fit the original theories, which posed serious challenges to the Gestalt framework. Even more devastating to the development of Gestalt psychology was the emergence of the Nazi regime in Germany from 1933 to World War II. In this period, many of the psychology professors at German universities lost their posts because of the discrimination and prosecution of Jews, so they emigrated to the U.S. to take on new positions there. The works by German psychologists who stayed, for instance, Edwin Rausch’s monograph on “summative” and “nonsummative” concepts ( 1937 ) and Wolfgang Metzger’s (1941) psychology textbook, were largely ignored outside Germany. Metzger’s synoptic account of research on the Gestalt theory of perception entitled “Gesetze des Sehens” (“Laws of seeing”), first published in 1936 and later reissued and vastly expanded three times, was only translated into English in 2006.

After emigrating to the U.S., the founding fathers of Gestalt psychology did not perform many new experiments. Instead, they mainly wrote books in which they outlined their views (e.g., Koffka, 1935 ; Köhler, 1940 ; Wertheimer, 1945 ). The major exception was Köhler who had taken up physiological psychology using EEG recording and other methods in an attempt to directly verify his isomorphism postulate. Initially, his work with Hans Wallach on figural aftereffects appeared to support his interpretation in terms of satiation of cortical currents ( Köhler & Wallach, 1944 ). Afterwards, he was able to directly measure cortical currents—as EEG responses picked up from electrodes at the scalp—whose flow direction corresponded to the direction of movement of objects in the visual field ( Köhler & Held, 1949 ).

Soon after that breakthrough, however, Lashley and colleagues ( Lashley, Chow, & Semmes, 1951 ) performed a more critical test of Köhler’s electric field theory and its underlying postulate of isomorphism. If the flows of current picked up from the scalp in Köhler and Held’s experiments indeed reflected the organized pattern of perception and not merely the applied stimulation, and if that pattern of perception would result from a global figure-field across the whole cortex, a marked alteration of the currents should distort the perception of these visual figures. By inserting metallic strips and metal pins in large regions of the visual cortex of rhesus monkeys, Lashley et al. could short-circuit the cortical currents. Surprisingly, the monkeys could still perform the learned shape discriminations, demonstrating that global cortical currents were not a necessary condition for pattern perception. In subsequent experiments, Sperry and colleagues ( Sperry, Miner, & Myers, 1955 ) performed extensive slicing and dense impregnation with metallic wires across the entire visual cortex of cats, and showed that these animals too could still perform rather difficult shape discriminations (e.g., between a prototypical triangle and distorted variants). Together, these two studies effectively ruled out electrical field theory as an explanation of cortical integration and undermined the empirical basis of any isomorphism between cortical flows of current and organized patterns of perception. Köhler (1965) naturally reacted to these developments but his counterarguments and suggestions for further experiments were largely ignored, and to most scientists at the time, the matter was closed. Electrical field theory, which had been one of the pillars of Gestalt psychology’s scientific basis, was considered dead and buried.

While Gestalt psychology declined in the English-speaking world after World-War II, Italy remained a stronghold of Gestalt psychology. For instance, Metzger dedicated the third edition of his “Gesetze des Sehens” to his “Italian and Japanese friends.” Among his friends were Musatti, Metelli, and Kanizsa—three major figures in Italian psychology. In spite of being Benussi’s student and successor (from the Graz school), Cesare Musatti was responsible for introducing the Berlin school of Gestalt psychology in Italy and training important students in this tradition—most notably Metelli and Kanizsa, whose contributions continue to be felt today. Fabio Metelli is best known for his work on the perception of transparency (e.g., Metelli, 1974 ). Gaetano Kanizsa’s most famous studies were performed in the 1950s with papers on subjective contours (e.g., the so-called Kanizsa triangle), modes of color appearance, and phenomenal transparency ( Kanizsa, 1954 , 1955a , 1955b ), although their impact came much later, when he started to publish in English ( Kanizsa, 1976 , 1979 ).

In addition to Italy, Gestalt psychology was also strong in Belgium and in Japan. Albert Michotte became famous for his work on the perception of causality ( 1946/1963 ), arguing strongly against an inferential, associationist, empiricist account of it, like other Gestalt psychologists had done for other aspects of perception. For him, causality is perceived directly, not derived from more primitive sensations through some cognitive operation, and this percept could be shown to be tightly coupled to specific higher-order attributes in the spatiotemporal events presented to observers. He also introduced the notions of modal and amodal completion ( Michotte, Thinès, & Crabbé, 1964 ), and studied several configural influences on these processes. (For a further discussion of Michotte’s heritage, see Wagemans, van Lier, & Scholl, 2006 .) Building on earlier collaborations of Japanese students with major German Gestalt psychologists (e.g., Sakuma with Lewin, Morinaga with Metzger), Gestalt psychology continued to develop in Japan after World-War II. For instance, Oyama did significant work on figural aftereffects (e.g., Sagara & Oyama, 1957 ) and perceptual grouping (e.g., Oyama, 1961 ).

2.4 The Current Status of Gestalt Psychology

Despite signs of well-deserved respect in the U.S. and in Germany (e.g., Köhler’s APA presidency in 1957; Wertheimer’s posthumous Wilhelm Wundt Medal in 1983), the ideas of the Gestaltists were received with ambivalence. On the one hand, they were recognized for raising central issues and provoking important debates in psychology, theoretical biology, and other fields, but on the other hand, their mode of thinking and research style did not sit comfortably in the intellectual and social climate of the postwar world, and they were confronted with vehement criticism. Two sets of explanations have been given for this outcome ( Ash, 1995 ). The first emphasizes institutional, political, and biographical contingencies. Koffka, Köhler and Wertheimer all left for the U.S. and obtained positions where they could do excellent research but could not train PhDs. The Gestalt school’s further expansion was also handicapped by the early deaths of Max Wertheimer in 1943 and Kurt Koffka in 1941, as well as many other Gestalt psychologists of the first and second generation (e.g., Duncker, Gelb, Lauenstein, Lewin, von Restorff). In Germany, Metzger, Rausch, and Gottschaldt did have a large number of PhD students, but few of them carried on in the Gestalt tradition. A notable exception is Lothar Spillmann, who obtained his D. Phil. with Metzger in Münster in 1964 and who pioneered the impact of Gestalt ideas in modern neurophysiology ever since (e.g., Spillmann, 1999 , 2009 ).

The second set of explanations concerns scientific issues of a methodological and conceptual nature (summarized in the left column of Table 4 ). Compared to the rigor of psychophysics and behaviorism, Gestalt psychology was severely criticized for offering mere demonstrations, using either very simple or confounded stimuli, formulating laws with little precision, and adding new “laws” for every factor shown to have an influence on perceptual organization. In the 1950s and 1960s, its critics increasingly insisted on causal explanations, by which they meant cognitive operations in the mind that could be modeled as computer algorithms or neural mechanisms that could be attributed to the properties of single cells that were discovered by Hubel and Wiesel in that period. In addition, serious conceptual limitations appeared when Gestalt thinking was extended to other areas such as personality and social psychology (e.g., Richard Crutchfield, Solomon Asch, Fritz Heider, David Krech). The further the metaphors were stretched, the harder it became to connect them to Köhler’s concept of a self-organizing brain and his speculations about electromagnetic brain fields.

Problems in old-school Gestalt psychology and how they are solved in contemporary research

Note . 1 = Paper 1 and 2 = Paper 2.

Despite these criticisms, Gestalt thinking did not disappear from the stage completely. In the slipstream of Shannon’s information theory, a few researchers tried to provide a quantitative underpinning to the central Gestalt notion of simplicity (e.g., Attneave, 1954 ; Attneave & Arnoult, 1956 ; Hochberg & McAlister, 1953 ; Leeuwenberg, 1969 , 1971 ; for a review, see Hatfield & Epstein, 1985 ). A number of independent, original scientists working on perception and information processing kept some Gestalt issues on the research agenda (e.g., Fred Attneave, Wendell Garner, Julian Hochberg, Irvin Rock). These became more prominent again with the discovery of true Gestalt phenomena such as global precedence in hierarchical letters (e.g., Navon, 1977 ), configural superiority effects based on emergent features (e.g., Pomerantz, Sager, & Stoever, 1977 ), and the importance of hierarchical structure in perceptual representations (e.g., Palmer, 1977 ). The experimental paradigms were derived from standard methods in cognitive psychology, and the results were incorporated into mainstream information-processing accounts (e.g., Beck, 1982 ; Kubovy & Pomerantz, 1981 ). In the major alternative approaches to visual perception—the ecological (e.g., Gibson, 1971 ) and computational (e.g., Marr, 1982 ) approaches—the influence of Gestalt thinking has also been acknowledged explicitly. In the last two or three decades, perceptual grouping and figure-ground organization—the most central topics of Berlin school research—have returned to center stage (e.g., Kimchi, Behrmann, & Olson, 2003 ), although the relationship to the original Gestalt theory (e.g., two-sided dependency between wholes and parts, minimum principle) is not always clear.

In the remainder of this paper, as well as in a second more theoretically oriented paper ( Wagemans et al., 2012 ), we review the later developments in more detail (summarized in the right column of Table 4 ). We start with research on perceptual grouping in simple displays (Section 3) and extend this to contour grouping, integration, and completion in more complex shapes and real-world images (Section 4). In the next section, we cover research on figure-ground perception, where many of the factors affecting grouping, in addition to unique factors, exert an influence (Section 5). Although links to neural mechanisms are mentioned throughout, we also provide a more integrated account of the literature on the neural mechanisms of contour grouping and figure-ground organization in a separate section (Section 6). This review demonstrates that research from the last two or three decades has addressed (and partially solved) some of the major methodological and conceptual shortcomings in old-school Gestalt psychology.

3 Perceptual Grouping

3.1 introduction.

Historically, the visual phenomenon most closely associated with perceptual organization is grouping: the fact that observers perceive some elements of the visual field as “going together” more strongly than others. Indeed, perceptual grouping and perceptual organization are sometimes presented as though they were synonymous. They are not. Grouping is one particular kind of organizational phenomenon, albeit a very important one. Another is figure-ground organization. In general, grouping determines what the qualitative elements of perception are, and figure-ground determines the interpretation of those elements in terms of their shapes and relative locations in the layout of surfaces in the 3-D world.

Max Wertheimer first posed the problem of perceptual grouping in his ground-breaking 1923 paper by asking what stimulus factors influence the perceived grouping of discrete elements. He first demonstrated that equally spaced dots do not group together into larger perceptual units, except as a uniform line ( Figure 1A ) and then noted that when he altered the spacing between adjacent dots so that some dots were closer than others, the closer ones grouped together strongly into pairs ( Figure 1B ). This factor of relative distance, which Wertheimer called proximity , was the first of his famous laws or (more accurately) principles of grouping.

Illustration of several grouping principles (adapted from Palmer, 2002a ).

Wertheimer went on to illustrate other grouping principles, several of which are portrayed in Figure 1 . Parts C, D, and E demonstrate different versions of the general principle of similarity : all else being equal, the most similar elements (in color, size, and orientation for these examples) tend to be grouped together. Another powerful grouping factor is common fate : all else being equal, elements that move in the same way tend to be grouped together. Notice that both common fate and proximity can actually be considered special cases of similarity grouping, with velocity and position as the relevant properties, respectively. Further factors influencing perceptual grouping of more complex elements, such as lines and curves, include symmetry ( Figure 1G ), parallelism ( Figure 1H ), and continuity or good continuation ( Figure 1I ). Continuity is important in Figure 1I because observers perceive it as containing two continuous intersecting lines rather than as two angles whose vertices meet at a point. Figure 1J illustrates the effect of closure : all else being equal, elements that form a closed figure tend to be grouped together. This display also shows that closure can dominate continuity, since the very same elements that were organized as two intersecting lines in Figure 1I are now organized as two angles meeting at a point in part Figure 1J .

One might think that such grouping principles are mere textbook curiosities only distantly related to normal perception. On the contrary, they pervade virtually all perceptual experiences because they determine the objects and parts that people perceive in the environment. (Hence, they also affect other sensory modalities; for a thorough discussion of grouping principles in audition, see Bregman, 1990 ; for a recent review of Gestalt principles in tactile perception, see Galace & Spence, 2011.) A practical application of the Gestalt principles is camouflage, which results when the same grouping processes that would normally make an organism stand out from its environment as a separate object, cause it to be grouped together with its surroundings instead. For instance, the same leopard that is clearly visible when it is seen in a tree against the uniform sky is difficult to see against a mottled, leafy backdrop—until it moves. Even perfect static camouflage is undone by the principle of common fate. In sum, camouflage and camouflage breaking provide an ecological rationale for the principles of grouping.

Since the early days of Gestalt psychology, considerable progress has been made, including (1) the discovery of additional principles, (2) the experimental measurement of the strength of grouping factors and the development of quantitative laws, as well as (3) new insights into the level of processing at which perceptual grouping happens. These new developments will be described in the next section, where we will also discuss their possible structural and ecological basis.

3.2 New Principles of Grouping

3.2.1 generalized common fate.

One of the most powerful of the classic grouping principles is common fate—the tendency for elements that “move together” to be perceived as a unitary entity ( Wertheimer, 1923 ). The possibility that Wertheimer may have had a much broader range of phenomena in mind, however, is suggested by a passage of his seminal article that is not widely known because it was not included in Ellis’s translation ( Wertheimer, 1923/1938 ): “Also this principle [of common fate] is valid in a wide range of conditions; how wide is not yet investigated here” ( Wertheimer, 1923 , p. 316; our own translation). In this vein, Sekuler and Bennett (2001) presented an extension of common fate to grouping by common luminance changes. They found that when elements of a visual scene become brighter or darker simultaneously, even if they have different luminances throughout, observers have a powerful tendency to group those elements perceptually. It is as though the principle of common fate operates not only for the common motion of elements through 3-D physical space, but through luminance space as well. The structural rationale for generalized common fate is clear: It is another example of similarity grouping, but based on similarity of changes in feature values, such as luminance or position, rather than on the similarity of the feature values themselves. An ecological rationale for grouping by common luminance changes might lie in the simultaneous brightening or darkening that occurs across a spatial area when the level of illumination changes (e.g., with the appearance of sunlight or shadows; see also van den Berg, Kubovy, & Schirillo, 2011 ).

3.2.2 Synchrony

Synchrony is the tendency for elements that change simultaneously to be grouped together ( Alais, Blake & Lee, 1998 ; Lee & Blake, 1999 ). The changes do not have to be in the same direction, however, as they do in generalized common fate. A random field of black and white dots whose luminances change in polarity randomly over time against a gray background, for example, will segregate into two distinct regions if the dots in one area change synchronously rather than randomly. Grouping by synchrony can be considered as an even more general form of common fate in which the simultaneous changes do not have to involve either motion, as in classic common fate, or common direction of change, as in generalized common fate. The structural basis for grouping by synchrony is clear: the simultaneous occurrence of visible changes of the elements that are grouped. Such grouping makes sense because it reflects a strong temporal regularity in the stimulus event.

The ecological rationale behind grouping by synchrony is far less clear, however. Objects in the natural environment seldom change their properties in different directions or along different dimensions in temporal synchrony. Indeed, it is difficult even to devise plausible examples of ecological situations that would exhibit this kind of temporal regularity without some form of extended common fate being involved. Nevertheless, synchrony grouping may arise from some very general nonaccidentalness detection mechanism, possibly connected to the perception of causality (e.g., Michotte, 1946/1963 ). The argument is that the temporal coincidence of multiple changes is unlikely to be due to chance alone, and so it must have some common underlying cause related to an ecological event that relates the synchronously changing elements.

A radically different and quite controversial, rationale is that temporal synchrony of changes drives grouping because synchrony of neural firings is the physiological mechanism by which the brain codes all forms of grouping (e.g., Milner, 1974 ; von der Malsburg, 1981 ). The argument is that if the environment drives the neural substrate to produce synchronous firing by virtue of synchronous changes, the changing elements will automatically be grouped because of the synchronous firing. Some researchers report evidence that seems to support this claim (e.g., Gray & Singer, 1989 ; Singer & Gray, 1995 ), but others disagree (e.g., Shadlen & Movshon, 1999 ). This issue is discussed further in the second paper ( Wagemans et al., 2012 ; Section 4). Further controversy surrounds synchrony grouping because it has been claimed that such grouping effects are actually produced by stimulus artifacts that can be detected by the early visual system ( Farid, 2002 ; Farid & Adelson, 2001 ). These challenges are complex, but the bottom line is that both the existence of grouping synchrony and the mechanism by which it occurs are currently unclear. In general, these controversies show quite clearly that the interest in perceptual grouping principles remains strong in contemporary research.

3.2.3 Common region

Common region is the tendency for elements that lie within the same bounded area (or region) to be grouped together ( Palmer, 1992 ). An illustration is provided in Figure 1K , where the black dots that lie within the same ovals are likely to be grouped into pairs. The structural basis for grouping by common region appears to be that all the elements within a given region share the topological property of being “inside of” or “contained by” some larger surrounding contour. If it is viewed as similarity of containment, it can be related to several other grouping principles based on similarity (e.g., color, orientation, and size). Common region also appears to have an ecological rationale arising from textures and hierarchically embedded parts. When a bounded region encloses a number of image elements, they are likely to be elements on the surface of a single object, such as a leopard’s spots or the features of a face, rather than independent objects that just happen accidentally to lie within the same bounding contour.

Experimental evidence for the existence of common region as a grouping factor comes from studies using the Repetition Discrimination Time or RDT method ( Beck & Palmer, 2002 ; Palmer & Beck, 2007 ). In a speeded discrimination task, observers were able to report the shape of a repeated element more quickly in a line of otherwise alternating shapes (e.g., squares and circles) when the repeated shapes were located within the same surrounding region than when they were located in two separate regions.

3.2.4 Element connectedness

Element connectedness is the tendency for distinct elements that share a common border to be grouped together. The important structural basis for this form of grouping is the topological property of connectedness ( Palmer & Rock, 1994 ). Connectedness can be considered as the limiting case of the classic factor of proximity, but Palmer and Rock argued that framing it this way puts the cart before the horse, in the sense that one needs distinct units to speak meaningfully about their distance in the first place. The compelling rationale for element connectedness is ecological: Pieces of matter that are physically connected to each other in 3-D space are the primary candidates for being parts of the same object, largely because they tend to behave as a single unit. The bristles, metal band, and handle of a paint brush, for example, constitute a single object in large part because of their connectedness, as demonstrated by the fact that when you push one part, the other parts move rigidly along with it.

The effectiveness of element connectedness was demonstrated in a behavioral task using the RDT method ( Palmer & Beck, 2007 ). As was the case for grouping by common region, displays with elements that were connected to each other produced reliably faster responses than displays with unconnected elements. Another behavioral result that provides striking support for the importance of element connectedness comes from a neuropsychological study by Humphreys and Riddoch (1993) . Their patient, who was afflicted with Balint’s syndrome—a condition resulting from bilateral damage to parietal cortex that results in a deficit in perceiving more than a single “object” at any given time—was unable to discriminate between arrays containing many circles of just one color (either all red or all green) and arrays in which half of the circles were red and the other half green. However, if pairs consisting of one red circle and one green circle were connected by lines, the same patient was able to make the discrimination between one-color and two-color arrays. Unifying a pair of circles through element connectedness thus appears to enable these patients to perceive them as a single perceptual object so that they could see two circles at once, a feat that was impossible for them in the absence of the connecting line.

3.2.5 Uniform connectedness

This principle represents something of a departure from standard Gestalt ideas about perceptual organization because it addresses the question of how the initial organization into elements might occur. In his classic article on grouping, Wertheimer (1923) never actually mentioned where the to-be-grouped elements came from. Presumably, he believed that they were somehow derived from the grouping principles he articulated, but Palmer and Rock (1994) argued that they arise from the earlier organizational process of uniform connectedness (UC), which is the principle by which the visual system initially partitions an image into a set of mutually exclusive connected regions having uniform (or smoothly changing) properties, such as luminance, color, texture, motion, and depth. The UC elements thus created form the entry level units into a part-whole hierarchy that is created by grouping together different UC regions and, if necessary, by parsing them into lower-level elements at deep concavities (e.g., Hoffman & Richards, 1984 ).

Palmer and Rock’s claims regarding the foundational status of UC have not been uniformly accepted. Peterson (1994) , for instance, argued that UC is one of many properties relevant to partitioning the visual field, and that UC units are not entry-level units. Kimchi (2000) examined the role of UC in experiments designed to reveal the gradual emergence, or microgenesis, of organizational processes using a primed matching task with displays containing connected or disconnected elements. The complex results she obtained were not consistent with UC being the sole determinant of entry-level units in a part-whole hierarchy, as Palmer and Rock (1994) proposed. Rather, they showed that collinearity and closure were at least as important, if not more so, in the initial organization that can be tapped by such methods. Nevertheless, the theoretical rationale for some organizational process like UC to contribute to creating a set of potential perceptual units on which further grouping and parsing can operate seems sound. Indeed, something like it is a standard assumption in most theories of computational vision (e.g., Marr, 1982 ).

Whereas the research on grouping principles, as described above, provides predictions about what elements in a display are likely to be grouped together, it does not reveal how strong each of the grouping principles is. This is the focus of the next sections, covering studies applying static and dynamic stimuli, respectively.

3.3 Grouping Principles in Discrete Static Patterns

3.3.1 conceptual background.

Starting with Wertheimer (1923) , researchers have often used dot lattices to quantify grouping. A dot lattice is a collection of dots in the plane which is invariant under at least two translations, a (with length |a|) and b (whose length is |b|≥ |a|). These two lengths, and the angle between the vectors, γ (constrained by 60° ≤ γ ≤ 90°), define the basic structure of the lattice, by defining the parallelogram between each quartet of dots in the lattice ( Kubovy, 1994 , extending the work of Bravais, 1850/1949 ; see Figure 2A ). The diagonals of this parallelogram are denoted c and d (where |c|≤|d|). In its canonical orientation, a is horizontal. More generally, the orientation of the lattice can be defined by the angle θ (measured counterclockwise) and |a| is called the scale of the lattice. Since scale is irrelevant to the invariant properties of the lattice and unimportant for grouping over a reasonable range, the relevant parameters are |b|/|a| and γ ( Figure 2B ). With these two parameters, six different types of lattices can be defined, each characterized by their symmetry properties.

(A) Defining features of a dot lattice stimulus. (B) Two-dimensional space and nomenclature of dot lattices. Adapted from Kubovy (1994) , with permission.

When grouping by proximity is pitted against grouping by similarity, displays consist of at least two kinds of elements (called motifs), separated by one of the translation components, resulting in dimotif lattices ( Figure 3 ; see Grünbaum & Shephard, 1987 ). In order to characterize the relation between two grouping principles, one must construct grouping indifference curves ( Figure 4 ), similar to the indifference curves used in micro-economics ( Krantz, Luce, Suppes, & Tversky, 1971 ): Imagine a consumer who would be equally satisfied with a market basket consisting of 1 kg of meat and 4 kg of potatoes and another consisting of 2 kg of meat and 1 kg of potatoes. In such a case, the (meat, potato) pairs (1, 4) and (2, 1) both lie on an indifference curve.

Two dimotif rectangular dot lattices with | b | | a | = 1.2 .

Two grouping indifference curves. The abscissa, δ a , represents the difference in luminance between adjacent elements of a . The ordinate, | b |, represents the distance between the dots of b (assuming | a | = 1). Only the equilibrium grouping indifference curve is achievable without independently measuring the strength of grouping by proximity. The methods to be described later allow us to plot a family of indifference curves. (The θ values are different for each of the four dot lattices.)

With these tools in hand, two important questions regarding perceptual grouping can be formulated. First, when several orientations can be perceived based on grouping by proximity in a particular dot lattice, what determines the preferred grouping? Is the outcome determined by the relative distance alone, or also by the angle between the competing organizations (an aspect that affects the global symmetry of the lattice and the way the overall configuration looks)? Second, when grouping by proximity and grouping by similarity are concurrently applied to the same pattern, what rule governs their joint application? Are these two principles combined additively or not? We briefly review the most important attempts to address these two questions. The initial studies always pitted grouping by proximity against grouping by similarity.

3.3.2 Initial attempts to quantify grouping by proximity by pitting it against similarity

The first to systematically study grouping by proximity in interaction with similarity was Rush (1937) . In her experiment she showed observers sequences of dot lattices in which the distance between dots in one orientation was held constant, and the distance between dots in another orientation was reduced from trial to trial. She assumed—incorrectly as argued below—that one could measure the strength of the two principles by finding their point of equilibrium, and concluded that “…it may be said that Similarity equals about 1.5 cm of Proximity” (p. 90).

Roughly two decades later, Hochberg and Silverstein (1956 , unaware of Rush’s work, as a footnote in Hochberg & Hardy, 1960 , attests) also set out to solve the problem of measuring the strength of grouping by similarity by pitting it against grouping by proximity. In manipulating luminance differences or distances between dots, they produced grouping indifference curves ( Figure 4 ). Reanalysis showed that an additive combination of proximity and similarity described their results best. Unfortunately, the logic employed by Hochberg and his colleagues suffered from the same flaw as Rush. Their method produced only one grouping indifference curve—the one for which both groupings are in equilibrium. Their method cannot produce grouping indifference curves for which one principle is 2× or 3× as strong as the other, which are needed to measure the relative strengths of the two principles.

Quinlan and Wilton (1998) studied the relations between grouping by proximity and two forms of grouping by similarity (by color and by shape). Their stimuli consisted of strips of seven elements, with the center element as the target. They manipulated proximity by slightly shifting the left or right set of three elements, and they also manipulated color and shape similarity. Observers were asked to rate the degree to which the target grouped with the elements on the left or on the right. Although the conception of the experiment is elegant, its reach was curtailed because each grouping principle was either present or absent. Had Quinlan and Wilton used a design in which each type of grouping was a multilevel factor, they could have addressed the additivity question (i.e., the second question introduced above), but they did not.

Oyama, Simizu, and Tozawa (1999) presented rectangular dimotif lattices for 3 s and asked observers to indicate continuously with a joystick whether they saw horizontal or vertical grouping. The horizontal separation was increased by 15’ after a “horizontal” response, and decreased by that amount after a “vertical” response. Using a double-staircase method, the ratio of vertical to horizontal distances was determined that matched a particular dissimilarity. This method produced more complete equilibrium grouping indifference curves than were obtained by Hochberg and his colleagues.

3.3.3 The pure–distance law and the additivity of grouping principles

Oyama (1961) was the first to show that one can measure the strength of grouping by proximity without pitting it against another grouping principle (e.g., grouping by similarity). Using rectangular dot lattices at a fixed orientation, he recorded the amount of time subjects reported seeing the competing horizontal and vertical groupings. The ratio of the time they saw the horizontal and vertical organizations was found to be a power function of the ratio of the horizontal and vertical distances t h /t v = (d h /d v ) −α , with α ≈ 2.89.

Using dot lattices at near-equilibrium, Kubovy and Wagemans (1995) and Kubovy, Holcombe, and Wagemans (1998) demonstrated that grouping by proximity can be understood as the outcome of a probabilistic competition among potential perceptual organizations. The basic idea is simple. If the distances between dots in two orientations of the lattice are equal, the chances of seeing one orientation or the other are equal too. If one distance becomes larger than the other, the relative chance of seeing that orientation decreases. If the ratio of the longer to the shorter vector is larger than about 1.5, grouping along that orientation is almost never seen. Kubovy and colleagues presented different kinds of dot lattices for 300 ms each and asked observers to indicate the perceived orientation. They could then use the frequencies of the perceived orientations over a large number of trials as estimates of the probabilities, and plot the relative frequencies as a function of relative distance. Their results (shown schematically in Figure 5 ) were remarkable. All the values of the log-odds fell on the same line, called the attraction function . Its slope is a person-dependent measure of sensitivity to proximity. Although the (relative) strength of grouping decays as an exponential function of (relative) distance, the attraction function in log-space is linear. The fact that all data points—obtained with all pairs of distances and all relative orientations (i.e., all points in the 2-D lattice space of Figure 2B )—could be fitted well by a single straight line indicates that grouping by proximity depends only on the relative distance between dots in competing organizations, not on the overall configuration in which the competition occurs (i.e., the lattice type, each with its own symmetry properties). Hence, this result, which was called the Pure Distance law provided a satisfactory answer to the first question raised above.

The pure distance law (adapted from Kubovy et al., 1998 , with permission).

Once it has been established how grouping varies as a function of relative distance, the effect of conjoined grouping principles can be determined by measuring a family of grouping indifference curves. Kubovy and van den Berg (2008) presented participants with rectangular lattices of dots of different contrasts. Dots with the same contrast were either arranged along the shorter axis of each rectangle of dots within the lattice (similarity and proximity in concert) or arranged along the longer axis (similarity and proximity working against each other). Dot lattices varied across two dimensions: the ratio between the short and long axis of each rectangle of dots within the lattice and the contrast difference between the different arrays of dots. As in the previous studies, each lattice was presented for 300 ms, and participants were asked to indicate which of the four orientations best matched the perceived arrangement of the dots in the lattice. By plotting the log likelihood of reporting the direction of the long axis versus the short axis as a function of the ratio of the length of the long and short axis for different values of the contrast difference between dots (shown schematically in Figure 6A ), a family of grouping indifference curves was then obtained (depicted in Figure 6B ). Because these indifference curves are parallel in log-odds space, the conjoined effects of proximity and similarity are called additive. Using lattices in which dots were replaced by Gabor elements, Claessens and Wagemans (2005) came to similar conclusions regarding proximity and collinearity. These results, therefore, provide a clear answer to the second question raised above.

The conjoined effects of proximity and similarity are additive. The dashed lines in (A) turn into grouping indifference curves in (B). Adapted from Kubovy and van den Berg (2008) , with permission.

3.4 Grouping Principles in Discrete Dynamic Patterns

Apparent motion is perceived when an object is presented in two or more successive frames at different spatial locations with proper durations and intervals. As discussed before, Wertheimer (1912) showed that under certain conditions it is possible to perceive pure motion, where motion is perceived without perceiving the moving object itself. The optimal timing and spacing between successively presented object presentations was investigated in more detail by Korte (1915) , who found a direct relationship between the optimal temporal and the optimal spatial interval for perceived apparent motion. Later studies, however, have shown that the relationship between the optimal temporal and spatial interval depends on the stimuli used. For example, using horizontal arrays of dots that were displaced on successive frames, Burt and Sperling (1981) found that the spacing of the dots in the array strongly influenced the apparent motion percept in addition to the effects of the temporal interval between frames and the spatial displacement of the entire array.

The influence of spatial and temporal factors in apparent motion was further investigated using the Ternus display ( Kramer & Yantis, 1997 ; Pantle & Picciano, 1976 ; Ternus, 1926 ; Wallace & Scott-Samuel, 2007 ), in which an array of three dots is presented across two frames at different spatial locations. When the two frames are presented in rapid succession (i.e., with a short inter-stimulus interval), it appears that the outmost dot is displaced while the center two dots appear to be stationary: element motion occurs. When the temporal interval between the successive frames is longer, the entire array of dots appears to jump: group motion is perceived. The two different types of perceived apparent motion represent two different solutions to the correspondence problem ( Ullman, 1979 ), referring to the task of matching the objects in the first frame to the (possibly displaced) objects in the second frame. Whether element or group motion was perceived was found to depend on the properties of the individual stimuli in both frames such as their features ( Dawson, Nevin-Meadows, & Wright, 1994 ), their size or the sharpness of their edges ( Casco, 1990 ), as well as on the presence of contextual elements affecting how they are grouped ( Kramer & Yantis, 1997 ) or how they are perceived in 3-D space ( He & Ooi, 1999 ).

The interaction between spatial and temporal aspects was further investigated by Gepshtein and Kubovy (2000) , who were able to determine the relationship between spatial grouping (determining which elements in each frame belong together) and temporal grouping (determining which elements across frames belong together), by using successive presentations of dot lattices— motion lattices —which allowed them to independently manipulate the strength of spatial and temporal groupings. A motion lattice ( Figure 7 ) is composed of two identical dot lattices, D 1 and D 2 , displayed in alternation. Two ratios determine the perceived motion: (1) the motion ratio r m = m 2 /m 1 , where m 1 and m 2 are the shortest and the next shortest spatial distances across which the apparent motion could occur between the frames; (2) the baseline ratio r b = b/m 1 , where b is the shortest spatial distance between the dots within D 1 and D 2 to which the apparent motion could apply. The orientation of a virtual line drawn through these dots is called the baseline orientation.

As in the classic Ternus display, two classes of motion can be perceived. First, element motion is now apparent motion from each dot in D 1 to a corresponding dot in D 2 (and vice versa as the dot lattices alternate). The log-odds of seeing m 2 rather than m 1 as a function of the ratio of the distances is called an affinity function , by analogy with the concept of an attraction function for static dot lattices ( Figure 8A ). Second, group motion is now apparent motion orthogonal to the baseline orientation ( Figure 7 ). Sequential models predict that if the spatial configuration of a stimulus remains constant, the likelihood of seeing group motion—an indicator of spatial grouping—cannot be affected by manipulations of the temporal configuration of the stimulus. However, the pattern of interaction in Figure 8B between r m , the temporal configuration of the stimulus, and r b , the relative density of the dots along the baseline, clearly refutes the sequential model.

(A) The affinity function. (B) The objecthood functions.

How spatial and temporal distances interact to determine the strength of apparent motion has been controversial. Some studies report space-time coupling : If the spatial or temporal distance between successive stimuli is increased, the other distance between them must also be increased to maintain a constant strength of apparent motion (i.e., Korte’s third law of motion). Other studies report space-time trade-off : If one of the distances is increased, the other must be decreased to maintain a constant strength of apparent motion. To establish what determines whether coupling or trade-off occurs, Gepshtein and Kubovy (2007) generalized the motion lattice of Figure 7 , as illustrated in Figure 9 , showing a temporal component of m 3 , T 3 , of twice the magnitude of the temporal component of m 1 , T 1 . By manipulating the spatial components of these motions, S 3 and S 1 from S 3 ≫ S 1 to S 3 ≪ S 1 , an equilibrium point between the extremes was found at r 31 = S 3 /S 1 , for which the probability of seeing the two motions was the same. If r 31 > 1 then space-time coupling holds; if r 31 < 1 then space-time trade-off holds. This suggests that previous findings on apparent motion were special cases and that the allegedly inconsistent results can be embraced by a simple law in which a smooth transition from trade-off to coupling occurs as a function of speed: Trade-off holds at low speeds of motion (below ≈ 12°/s), whereas coupling (Korte’s law) holds at high speeds. The deeper theoretical implications of these results for the visual system’s economy principles are discussed in the second review paper ( Wagemans et al., 2012 ; Section 4).

A six-stroke motion lattice. (A) The successive frames are superimposed in space. Gray levels indicate time. b is the baseline distance. (B) The time course of the display. The three most likely motions along m 1 , m 2 , and m 3 can occur because dots in frame f i can match dots in either frame f i+1 or frame f i+2 . (C–D) Conditions in which different motion paths dominate: m 1 in Panel C and m 3 in Panel D. (The stimuli were designed so that m 2 would never dominate.) Adapted from Gepshtein and Kubovy (2007) , with permission.

The above research on perceptual grouping in static and dynamic discrete patterns spans a complete century, from Schumann (1900) , Wertheimer (1912 , 1923 ) and Korte (1915) up until today. It was mainly using well-controlled, parametrically varied stimuli in order to isolate one factor or another, and trying to quantify its strength. In addition, it sparked a renewed interest in understanding the level at which perceptual grouping operates, which was addressed in studies that use somewhat richer stimuli with additional variations, more typical for naturally occurring stimulation.

3.5 At What Level Does Grouping Happen?

As described above, Wertheimer (1923) demonstrated powerful grouping effects due to a large number of stimulus variables (e.g., proximity, similarity, good continuation) using flat 2-D displays on the printed page (see Figure 1 ). Subsequent researchers have investigated where in the visual system these effects occur (i.e., before or after the construction of a 3-D representation of the image), by using various kinds of 3-D displays with depth cues, shadows, transparency, and other higher-level factors.

Rock and Brosgole (1964) conducted a classic experiment on this topic to examine whether grouping by proximity operated on retinal 2-D distances or perceived 3-D distances. Observers in a dark room saw a 2-D array of luminous beads either in the frontal plane (perpendicular to the line of sight) or slanted in depth so that the horizontal dimension of the array was foreshortened. The beads were actually closer together vertically than horizontally, so that when they were viewed in the frontal plane, observers always reported seeing them grouped into vertical columns rather than horizontal rows. The critical question was whether or not the beads would be grouped in the same way when the same lattice was viewed slanted in depth such that the beads were retinally closer together in the horizontal direction. When this array was viewed monocularly, so that the beads appeared to be in a frontal plane perpendicular to the line of sight (even though they were actually slanted in depth), observers perceived the grouping to change to a set of rows rather than columns, as one would expect based on retinal distances. However, when viewed binocularly, so that stereoscopic depth information enabled observers to see the beads slanted in depth, they reported grouping them into vertical columns, as predicted by postconstancy grouping based on a 3-D representation of perceived distances in the phenomenal environment (because the beads appeared to be closer in the vertical direction, as was actually the case in the physical world). Rock and Brosgole’s results therefore support the hypothesis that the final, conscious result of grouping occurs after binocular depth perception. Several phenomenological demonstrations supporting the same conclusion are provided by Palmer (2002b ; Palmer, Brooks & Nelson, 2003 ).

Rock, Nijhawan, Palmer and Tudor (1992) later investigated whether grouping based on lightness similarity happened before or after lightness constancy. Using displays that employed cast shadows and translucent overlays, they also found evidence that the final conscious result of grouping depended on a postconstancy representation that reflected the perceived reflectance of surfaces rather than the luminance of retinal regions. Analogous evidence that the final conscious organization resulted from a grouping process that operates on relatively late, postconstancy representations was reported by Palmer, Neff, and Beck (1996) for amodal completion and by Palmer and Nelson (2000) for illusory contours. Further results of Schulz and Sanocki (2003) support the view that prior to achieving the conscious result of perceptual grouping based on a 3-D postconstancy representation, some nonconscious grouping processes operate on a 2-D preconstancy representation. They used the same lightness displays as did Rock et al. (1992) , but included a brief, masked presentation condition in which they found that observers reported seeing an organization that is based on the retinal luminance of 2-D regions (see also van den Berg et al., 2011 ). Further evidence that grouping operations occur before constancy has been achieved is based on grouping effects that actually influence the achievement of constancy (see Palmer, 2003 ).

Perhaps the most parsimonious view consistent with the known facts is that grouping principles operate at multiple levels. It seems most likely that provisional grouping takes place at each stage of processing, possibly with feedback from higher levels to lower ones, until a final, conscious experience arises of a grouping that is consistent with the perceived structure of the 3-D environment. Whereas the above findings provide valuable information about the stages at which grouping operates, these studies have mainly employed relatively artificial stimuli. The next section is dedicated to the role of grouping in contour integration and completion, in ways that are closer to the processing of natural stimuli.

4 Contour Integration and Completion

4.1 introduction.

Studies in which grouping factors are isolated to quantify their strength are useful but understanding their role in everyday perception requires a different approach. An important task of natural vision is to identify and group together the portions of the 2-D retinal image that project from an object. In the simple case in which the object boundary projects as a single closed curve, the problem reduces to a problem of contour grouping or contour integration. From the fifty-year history of computer vision research, however, we know that this is a computationally difficult problem for a number of reasons (e.g., Elder, Krupnik, & Johnston, 2003 ). First, occlusions occur generically in natural images, resulting in a projection of the rim of the object as a disconnected set of contour fragments (see Figure 10 ). Also, where the figure-ground contrast is low, portions of the contour may not be detected, resulting in further fragmentation. To complicate matters further, natural images are often highly cluttered, such that for any given contour fragment, multiple other fragments could be the correct continuation of the contour. Thus, to effectively exploit contours for object segmentation, the visual system must be able to cope with uncertainty, using a relaxed form of perceptual contour closure that can work reliably even for fragmented contours (e.g., Elder & Zucker, 1993 ). Discovering the nature of these mechanisms is a central topic in modern perceptual organization research, involving a range of different methodologies, including psychophysics, neurophysiology, neuroimaging, ecological statistics, and computational modeling.

Object boundaries project to the image as fragmented contours, due to occlusions (dashed cyan line) and low figure/ground contrast (dashed red line).

Addressing the role of grouping under natural conditions requires a definition of the grouping primitives: What exactly are the elements being grouped? In the research with dot lattices reviewed above, the primitives are zero-dimensional points or dots, and proximity and similarity were the only cues involved. The study of contour grouping over oriented primitives such as bars or edges expands the grouping cues to also include good continuation. This maps directly onto related computer vision research, where the contour grouping problem is typically defined over local oriented edge elements detected using oriented linear filters (e.g., Canny, 1983 ) that can be loosely identified with receptive fields of simple cells in primate V1 ( Hubel & Wiesel, 1968 ). Even higher-level primitives can be used, for instance, connected contour fragments of arbitrary shape, which may have been separated by occlusions. This higher level of representation may play a role in perceptual completion (see also below), and could be mapped to extrastriate visual areas such as V4, where neurons are known to be selective for higher-order properties of shape ( Pasupathy & Connor, 1999 ). In psychophysics, this has motivated the use of fragmented object pictures, which can be used to study the dynamic interplay between perceptual grouping and object identification (e.g., Panis & Wagemans, 2009 ).

In the following subsections, we first review the research on the role of grouping principles for contour integration—research that generalizes properties discovered for individual cues in isolation to more natural conditions where multiple cues are present and the visual stimulus may be quite complex. In addition to psychophysical results, we review the ecological foundations of the problem, and discuss computational principles and possible neural mechanisms. We then turn to the specific problem of contour completion in cases of occlusion, before discussing general issues pertaining to both perceptual grouping and contour integration.

4.2 Grouping Principles for Contour Integration

4.2.1 proximity.

The principle of proximity states that the strength of grouping between two elements increases as these elements are brought nearer to each other, but how exactly does grouping strength vary as a function of their separation? As reviewed above, Oyama (1961) found that this relationship could be accurately described as a power law, whereas Kubovy and Wagemans (1995) employed an exponential model, consistent with random-walk models of contour formation ( Mumford, 1992 ; Williams & Jacobs, 1997 ). However, Kubovy et al. (1998) also noted that a power law model could fit their data equally well and found that the proximity cue was approximately scale-invariant: Scaling all distances by the same factor did not affect results. Since the power law is the only perfectly scale-invariant distribution, this last result adds strength to the power-law model of proximity, which has been used in subsequent studies (e.g., Claessens & Wagemans, 2008 ).

Perceptual scale invariance is rational if in fact the proximity of elements along real contours in natural images is scale invariant—that is, if the ecological distribution follows a power law. In support of this idea, Sigman, Cecchi, Gilbert, and Magnasco (2001) reported that the spatial correlation in the response of collinearly-oriented filters to natural images does indeed follow a power law. Quantitatively, however, the correspondence between psychophysics and ecological statistics is poor here: While Oyama estimated the perceptual power law exponent to be α ≈ 2.89, Sigman et al. estimated an ecological exponent of only 0.6, reflective of a much weaker cue to grouping. However, Sigman et al. (2001) did not restrict their measurements to pairs of neighboring elements on the same contour of the image. In fact, the measurements were not constrained to be on the same contour, or even on a contour at all, leading to a mixture between strongly-related and only weaklyrelated image features. Elder and Goldberg (2002) estimated these distributions more directly, asking human observers to label the sequence of elements forming the contours of natural images, with the aid of an interactive image editing tool. This technique allowed the measurements to be restricted to successive elements along the same contour, and yielded a clear power law with exponent α = 2.92, very close to the perceptual estimate of Oyama. Whether this exponent is independent of orientation in the image remains an interesting open question, but psychophysical data ( Claessens & Wagemans, 2008 ) suggest that at least perceptually this may not be the case.

In sum, the convergence between psychophysics and ecological statistics is compelling: Ecologically, proximity follows a power law and exhibits scale invariance, and these properties are mirrored by the psychophysical results. Thus, we have a strong indication that the human perceptual system is optimally tuned for the ecological statistics of proximity cues in natural scenes.

4.2.2 Good continuation

A second important grouping principle for contour integration is good continuation, which refers to the tendency for elements to be grouped to form smooth contours ( Wertheimer, 1923/1938 ). A very effective method for studying the principle of good continuation in cluttered images was developed by Field, Hayes, and Hess (1993) . In this method, a contour formed from localized oriented elements is embedded in a random field of homogeneously distributed distractor elements, in order to eliminate the role of proximity ( Figure 11 ). Aligning the contour elements tangentially to the contour makes the contour easily detected, whereas randomizing the orientation of the elements renders the contour invisible, clearly demonstrating the role of good continuation in isolation from proximity.

Example of stimuli devised by Field et al. (1993) to probe the role of good continuation in contour integration (adapted with permission).

These findings led Field et al. (1993) to suggest the notion of an association field that determines the linking of oriented elements within a local visual neighborhood ( Figure 12 ), a construct that is closely related to the machinery of cocircularity support neighborhoods, developed earlier for the purpose of contour refinement in computer vision ( Parent & Zucker, 1989 ).

Models of good continuation. (A) Cocircularity support neighborhood (adapted from Parent & Zucker, 1989 , with permission). (B) Association field (adapted from Field et al., 1993 , with permission).

Ecological data on good continuation have also emerged over the last decade. Kruger (1998) and later Sigman et al. (2001) found evidence for collinearity, cocircularity and parallelism in the statistics of natural images. Geisler, Perry, Super, and Gallogly (2001) found similar results using both labeled and unlabeled natural image data, in fairly close correspondence with the tuning of human perception to the good continuation cue. Geisler et al. (2001) treated contours as unordered sets of oriented elements, measuring the statistics for pairs of contour elements on a common object boundary, regardless of whether these element pairs were close together or far apart on the object contour. In contrast, Elder and Goldberg (2002) modeled contours as ordered sequences of oriented elements, restricting measurements to adjacent pairs of oriented elements along the contours. The likelihood ratios for two oriented elements to be neighboring elements on the same object boundary are much larger for the sequential statistics, reflecting a stronger statistical association between neighboring contour elements.

4.2.3 Similarity

The principle of similarity states that elements with similar properties (e.g., brightness, contrast, color, texture) are more likely to group than elements that differ on these dimensions, which has been demonstrated in a number of ways with dot patterns (see above). For oriented elements, studies have generally found a decline in contour integration performance for contrast reversals under certain conditions but not others, suggesting non-additive interactions with other grouping cues such as proximity and good continuation (e.g., Elder & Zucker, 1993 ; Field, Hayes, & Hess, 2000 ; Gilchrist, Humphreys, Riddoch, & Neumann, 1997 ; Rensink & Enns, 1995 ; Spehar, 2002 ). Elder and Goldberg (2002) explored the ecological statistics of similarity in edge grouping, coding similarity in terms of the difference in brightness and in contrast between the edges, and found that the brightness cue carries useful information for grouping but the contrast cue is relatively weak. Whereas Elder and Goldberg restricted their study to pairs of elements of the same contrast polarity, Geisler and Perry (2009) have more recently studied the ecological statistics of contrast polarity, demonstrating that it is also an informative cue for contour integration.

4.2.4 Closure

The role of closure in contour integration has been debated. Whereas Kovács and Julesz (1993) found superior detection performance for closed, roughly circular contours, compared to open curvilinear controls, these findings might also be based, in part, on good continuation alone. In fact, with stimuli more closely controlled for good continuation cues, Tversky, Geisler, and Perry (2004) found only a small advantage for closed contours and argued that this advantage could be due to probability summation rather than closure. While this negative result may seem inconsistent with the emphasis placed on closure in early Gestalt work, it is important to appreciate the exact nature of this early view, as expressed by Koffka (1935 , p. 150): “Ordinary lines, whether straight or curved, appear as lines and not as areas. They have shape, but they lack the difference between an inside and an outside… If a line forms a closed, or almost closed, figure, we see no longer merely a line on a homogeneous background, but a surface figure bounded by the line.” The original Gestalt claim was thus not that closure is a grouping cue per se, but rather that it somehow profoundly determines the final percept of form. In the same spirit, Elder and Zucker (1993 , 1994 ) argued that the most important role for closure was as a bridge from 1-D contour to 2-D shape, a suggestion that was supported by the finding that small changes in good continuation and closure can yield large changes in shape discriminability.

4.2.5 Symmetry and parallelism

The Gestaltists identified symmetry as a factor of “good shape” ( Koffka, 1935 ), although it seems to be easily overruled by good continuation and convexity ( Kanizsa, 1979 ). In the computer vision literature, symmetry has been used in numerous contour integration algorithms (e.g., Mohan & Nevatia, 1992 ; Stahl & Wang, 2008 ). Parallelism has been identified as a factor determining the perceptual simplicity of line configurations ( Arnheim, 1967 ), and as a grouping cue in computer vision algorithms (e.g., Jacobs, 2003 ; Lowe, 1985 ). In the ecological statistics literature, parallelism has been studied extensively as a cue for the grouping of oriented edge elements into contours ( Elder & Goldberg, 2002 ; Geisler et al., 2001 ; Kruger, 1998 ). Psychophysical evidence for the role of symmetry and parallelism in contour integration has been reported by Feldman (2007) , who showed that comparison of features lying on pairs of line segments is significantly faster if the segments are parallel or mirror-symmetric, suggesting a fast grouping of the segments based upon these cues. More recently, Machilsen, Pauwels, and Wagemans (2009) demonstrated enhanced detectability of bilaterally symmetric versus asymmetric closed forms, suggesting a role for more complex, global symmetry processing in contour integration. Physiologically, it is known that bilaterally symmetric patterns differentially activate human extrastriate visual areas V3, V4, V7 and LO, and homologous areas in macaque cortex ( Sasaki, 2007 ).

4.2.6 Convexity

Convexity has long been known as a grouping cue ( Rubin, 1927 ). In the computer vision literature, Jacobs (1996) also demonstrated its utility for grouping contour fragments that can then be used as features for object recognition. Liu, Jacobs, and Basri (1999) subsequently employed a novel psychophysical method to demonstrate the role of convexity in contour integration. Their method relies on the observation of Mitchison and Westheimer (1984) that judging the relative stereoscopic depth of two contour fragments becomes more difficult when the fragments are arranged to form a configuration with good continuation and closure. Using an elaboration of this method, Liu and colleagues showed that stereoscopic thresholds are substantially higher for occluded contour fragments that can be completed to form a convex shape, relative to fragments whose completion induces one or more concavities. This suggests that the visual system is using convexity as a grouping cue.

In sum, research on contour integration, using oriented elements or shape fragments, has demonstrated important roles for the principles of proximity, good continuation, similarity, closure, symmetry and parallelism. This research thus can be seen as an elaboration of early Gestalt work that established these principles phenomenologically. Importantly, however, work on contour integration has provided quantitative measures which have led directly to computational models and algorithms, and which have allowed direct comparison to the underlying ecological statistics of the problem and to neurophysiological results.

Whereas the preceding section discussed research on the integration of contour fragments, the next section turns to the specific problem of contour completion in cases of occlusion, which brings us another step closer to understanding the role of grouping in more complex tasks of natural vision.

4.3 Contour Completion

4.3.1 modal and amodal completion.

Whereas contour integration refers to the integration of discrete elements such as dots or oriented elements, contour completion refers to the integration of smooth extended contours, separated by gaps due to occlusion or camouflage. Stimuli used in the study of contour completion often include cues to relative depth or occlusion, such as T-junctions (see Figure 13 ). In Figure 13A , for example, the perceived unity of the black fragments and the perceived shape of the black surface behind the gray occluder appear to result from visual contour completion. This form of completion of the black shape behind the gray occluder is referred to as amodal completion ( Michotte et al., 1964 ). Although one has a compelling sense of continuity of the boundaries of the black surface behind the occluder, one does not actually see a contour. By contrast, illusory contours constitute an example of modal completion . They generate a percept of a contrast border in image regions that are physically homogeneous, such as the illusory edges of the white wedge in Figure 13B .

(A) Amodal completion of the black shape behind the gray shape. (B) A white shape seen on top of three black shapes. The perceived contours of this white shape have a sensory quality (hence, modal completion), although they are completely illusory. Adapted from Singh and Fulvio (2007) , with permission.

4.3.2 Grouping and shape problem

For contour completion, the visual system must solve two problems (see Figure 14 ). First, it must determine whether or not the two contour fragments are part of a single continuous contour: the grouping problem . Second, it must determine the shape of the missing portion of the contour: the shape problem .

Two curved fragments are seen to complete amodally behind the gray rectangle in (A), not in (B). (C) In case of amodal completion, an important issue regards the shape of the completed curve. Adapted from Singh and Fulvio (2007) , with permission.

As a solution to the grouping problem, Kellman and Shipley (1991) have proposed a relatability criterion. This criterion refers to the coding of contour geometry in terms of the positions and orientations of the edges of the contours. Two inducing contours are grouped if they satisfy two conditions. First, if extended linearly, these extensions must intersect and, second, the turning angle of the two edges should not exceed 90°. Evidence for the role of contour relatability has been found by means of observer ratings ( Kellman & Shipley, 1991 ), shape (fat/thin) discrimination performance ( Ringach & Shapley, 1996 ; Zhou, Tjan, Zhou, & Liu, 2008 ), depth discrimination performance ( Liu et al., 1999 ; Yin, Kellman, & Shipley, 2000 ), and interpolation settings ( Fulvio, Singh, & Maloney, 2008 ).

The shape problem involves determining the shape of the occluded portion of the contour. This is a highly under-constrained problem, since an infinite number of possible shapes could be hidden behind the foreground shape (see Figure 14C ). Human observers typically perceive only a small subset of these. This suggests that the visual system imposes strong constraints when generating and selecting the set of possible shapes. Different methods have been used to examine how the visual system solves the shape problem. For example, several studies have asked participants to draw the perceived trajectory of visually completed contours ( Takeichi, Nakazawa, Murakami, & Shimojo, 1995 ; Ullman, 1976 ). Other studies have asked observers to mark the farthest point along the interpolated contours ( Fantoni, Bertamini, & Gerbino, 2005 ; Guttman & Kellman, 2004 ; Takeichi et al., 1995 ), to match the perceived interpolated shape from a parametric family ( Singh, 2004 ), or to rate its overall degree of “roundedness” ( Fantoni & Gerbino, 2003 ). More recently, Fulvio et al. (2008) used a method that obtains interpolation settings (position and orientation) at multiple locations along the length of a partly-occluded contour. An examination of the precision and consistency of these settings showed that observers can interpolate a single, stable (self-consistent), smooth contour when the inducing contours are relatable, but not when they require an inflecting interpolating curve.

An empirically successful model which addresses the grouping problem and the shape problem simultaneously has been proposed by van Lier ( van Lier, 1999 ; van Lier, van der Helm, & Leeuwenberg, 1994 , 1995 ). In line with the descriptive simplicity principle (see Wagemans et al., 2012 ; Sections 5 and 6), this model postulates that an interpretation is judged not only by the complexities of the potentially occluding and occluded shape(s) but also by the complexity of the relative positions of these shapes. The combination with the lowest overall complexity is then taken to predict whether occlusion occurs, and if so, how the occluded shape looks like.

4.3.3 Contour interpolation and extrapolation

Good continuation is an important criterion in shape interpolation, but it is not perfectly clear what is meant by this term. Dating back to Wertheimer (1923 , especially his Figures 16 – 19 ), two aspects have been distinguished: (1) what geometric properties of the visible contours are used by human vision (e.g., orientation, curvature, rate-of-change of curvature, higher-order derivates) and (2) how are they combined to define the shape of the contour?

Contour geometry depends on surface geometry. The same curved contour segment (A) can correspond either to a locally convex (B) or a concave portion of a surface (C). Curvature on an object boundary can also arise because the axis of the object itself is curved (D). Adapted from Singh and Fulvio (2006), with permission.

Sample displays used by Driver and Baylis (1996) , adapted with permission. (A). Study display. (B) and (C). Figure and ground probes, respectively. In both B and C, the top probe has the same border as the study display.

These questions were addressed in studies of contour extrapolation (e.g., Singh & Fulvio, 2005 , 2007 ), in which observers adjusted the position and orientation of a line probe on the other side of an occluder ( Figure 15 ) at multiple distances from the point of occlusion in order to optimize the percept of smooth continuation. The findings suggested that observers use contour orientation and curvature, but not rate-of-change of curvature. The shape of visually extrapolated contours was best characterized by a decaying curvature. The results were modeled by a Bayesian interaction between a tendency to extend contour curvature and a prior tendency for straight contours.

(A) Measuring extrapolation of curvature by (B) asking observers to position and orient a small curved line fragment. Adapted from Singh and Fulvio (2007) , with permission.

Models of contour interpolation typically use just the position and orientation of the visible segments at their respective points of occlusion, but not their curvature (e.g., Fantoni & Gerbino, 2003 ; Kellman & Shipley, 1991 ; Ullman, 1976 ). The above results suggest, however, that interpolation models should use curvature as well, especially if they aim to model human contour interpolation. How much of the visible contours the visual system uses is still an open question. More flexible behavior can be obtained (in terms capturing various dependencies exhibited by human vision) using probabilistic models of contour interpolation rather than those based on fixed classes of shapes, or that minimize fixed geometric criteria (see Singh & Fulvio, 2007 ).

4.3.4 Surface geometry and layout

The dominant approach in contour completion has been to treat the problem in isolation (e.g., Kellman & Shipley, 1991 ), but there is growing evidence that visual contour completion is very much informed and guided by surface geometry and surface layout.

One aspect of surface geometry is curvature polarity, where a curved contour segment ( Figure 16A ) can correspond to a locally convex ( Figure 16B ) or a concave portion of a surface ( Figure 16C ). In addition, curvature on an object boundary can arise either because the axis of the object itself is curved (like a bending “ribbon”; Figure 16D ), or because of the changing width of the shape around a straight axis (a convex “bulge” or a concave “neck”; Figure 16B–C ). Experimental studies have shown that the convexity of the surface influences grouping in both contour completion ( Liu et al., 1999 ; Tse, 1999 ) and interpolated shape ( Fantoni et al., 2005 ; Fulvio & Singh, 2006 ). Moreover, the influence of surface geometry goes beyond local convexity to include skeletal shape description ( Fulvio & Singh, 2006 ).

In addition to surface geometry, surface layout also exerts an influence on contour completion, for example, by differences in perceived depth. In amodal completion, the completed contour tends to belong to the occluded surface. In modal completion, in contrast, it belongs to a nearer, occluding surface. Such effects of surface layout are not consistent with a single mechanism underlying both modal and amodal completion ( Anderson, Singh, & Fleming, 2002 ; Zhou et al., 2008 ). Instead of assuming two separate mechanisms for modal and amodal completion, however, it could also be assumed that the contour interpolation mechanism is flexible, in that it can take into account various image conditions (e.g., relative depth, photometric conditions, as well as surface geometry; Singh, 2004 ; Zhou et al., 2008 ). The exact mechanism underlying modal and amodal completion has been the topic of much recent debate (e.g., Anderson, 2007 ; Kellman, Garrigan, Shipley, & Keane, 2007 ).

In sum, when we explicitly study contour completion under occlusion, some additional issues arise, and research indicates that the mechanisms take more complex geometric aspects into account, that they are more sensitive to the configuration in which the visible contour fragments occur, and that they are generally more flexible, than in cases of contour completion without occlusion.

4.4 Some General Issues Regarding Perceptual Grouping and Contour Integration

While our review has thus far considered each individual Gestalt principle in turn and how they apply to contour integration and completion, there are key overarching questions that cut across all of these cases of perceptual grouping: (1) To what extent are the Gestalt laws innate or learned?; (2) how are they combined?; and (3) how can they be jointly represented in accurate computational models and useful algorithms?

4.4.1 Development

In general, Gestalt psychology has tended to emphasize the degree to which the Gestalt laws are innate or intrinsic to the brain rather than learned from past experience. Research suggests that infants are capable of grouping visual elements into unitary structures in accord with a variety of both classic and modern organizational principles (for a review, see Bhatt & Quinn, 2011 ). Infants as young as 3 to 4 months of age show grouping by good continuation, proximity, connectedness, and common region, and grouping by lightness similarity was observed even in newborns. However, only 6- to 7-month-olds appear to utilize form similarity to organize visual patterns ( Quinn & Bhatt, 2006 ), and 3-month-olds appear to be completely insensitive to closure ( Gerhardstein, Kovács, Ditre, & Feher, 2004 ), suggesting that not all grouping cues are readily available to young infants.

Furthermore, recent psychophysical studies of older children suggest that there is a protracted developmental trajectory for some perceptual organization abilities, even those that appear to emerge during infancy (e.g., Hadad & Kimchi, 2006 ; Hadad, Maurer, & Lewis, 2010a , 2010b ; Kimchi, Hadad, Behrmann, & Palmer, 2005 ; Kovács, 2000 ). For example, the Gestalt principles underlying contour grouping continue to develop in children through their late teens. These findings suggest that visual experience plays a role in at least some aspects of perceptual organization. Further support for this notion comes from studies demonstrating influence of perceptual learning on organizational abilities in infancy (e.g., Quinn & Bhatt, 2005 ), and the influence of associative learning ( Vickery & Jiang, 2009 ), and past experience ( Kimchi & Hadad, 2002 ) on perceptual grouping in adult observers.

4.4.2 Cue combination

One of the central questions in grouping concerns the way in which the brain combines multiple cues to yield a unitary organization. Historically, this problem has often been posed in terms of competitive interactions formulated either in descriptive terms (usually seeking compliance with the simplicity principle) or in probabilistic terms (usually Bayesian formulations which may or may not seek compliance with the Helmholtzian likelihood principle). (For more details on this, see Wagemans et al. (2012) , Sections 5 and 6.) However, in natural scenes, disparate weak cues can often combine synergistically to yield strong evidence for a particular grouping.

To explore this issue, Geisler et al. (2001) used a nonparametric statistical approach, jointly modeling the ecological statistics of proximity and good continuation cues as a 3-D histogram, to show that human observers combine these two classic Gestalt principles in a roughly optimal way. Elder and Goldberg (2002) demonstrated that the ecological statistics of proximity, good continuation, and similarity are roughly uncorrelated, so that to a first approximation the Gestalt laws can be factored: The likelihood of a particular grouping can be computed as the product of the likelihoods of each grouping factor in turn (or, equivalently, the log likelihood of the grouping factor is the sum of the log likelihoods of the grouping factors; for further explanation, see Claessens & Wagemans, 2008 ).

Elder and Goldberg’s (2002) approach also allowed quantification of the statistical power of each Gestalt cue, as the reduction in the entropy of the grouping decision given each cue individually. They found that proximity was by far the most powerful, reducing the entropy by roughly 75%, whereas good continuation and similarity reduced entropy by roughly 10% each. The most accurate grouping decisions could be made by combining all of the cues optimally according to the probabilistic model, trained on the ecological statistics of natural images. Such a statistically optimal combination of grouping cues has also received some psychophysical support ( Claessens & Wagemans, 2008 ).

4.4.3 Computational models

Numerous computer vision algorithms for grouping make use of the Gestalt factors described above (e.g., Elder et al., 2003 ; Estrada & Elder, 2006 ; Jacobs, 1996 ; Lowe, 1985 ; Sha’ashua & Ullman, 1988 ; Stahl & Wang, 2008 ). Most of these use the local Gestalt principles of proximity, good continuation, and similarity to group long chains under an explicit or implicit Markov assumption, while additional global factors of convexity ( Jacobs, 1996 ), closure ( Elder et al., 2003 ), and symmetry ( Stahl & Wang, 2008 ) have been employed to further condition the search. In addition, coarse-to-fine feedback techniques have been used as an alternative way to incorporate more global constraints into the grouping process ( Estrada & Elder, 2006 ). Grounding probabilistic algorithms in the ecological statistics of contour grouping avoids the ad hoc selection of algorithm parameters and optimizes performance on natural scenes ( Elder et al., 2003 ; Estrada & Elder, 2006 ).

Although the Gestalt principles of grouping were largely based on the analysis of figures in the 2-D image plane, more recent work derives these principles from the geometric laws of 3-D projection, within the theoretical framework of minimal viewpoint invariants ( Jacobs, 2003 ; Lowe, 1985 ). Briefly, the theory is based upon the assumption that the observer takes a general viewpoint position with respect to scenes. This assumption implies that certain so-called non-accidental properties in the 2-D proximal stimulus are most likely properties of the 3-D distal stimulus as well ( Binford, 1981 ; Lowe, 1985 ). Examples of such non-accidental properties are the geometric Gestalt principles relevant to contour grouping: proximity, good continuation, closure, convexity, parallelism, and symmetry (e.g., Wagemans, 1992 , 1993 ). This notion has played a central role as a bridge between the Gestalt grouping principles and object representation and recognition ( Biederman, 1987 ).

4.4.4 Conclusion

Research on principles of perceptual grouping has come a long way since Wertheimer’s (1923) phenomenological demonstrations. Using well-controlled discrete patterns, grouping by proximity could be quantified as a real law. In the last two decades or so, new grouping principles have been identified, and their functional role in the processing of more complex images occurring in real-world situations became a central focus. In much of this research, quantitative psychophysical work went hand-in-hand with the analysis of ecological statistics, the development of computational models and neurophysiological research. In Section 5, we see a similar evolution in research on the closely related problem of figure-ground organization. Section 6 is devoted to an integrated review of the research on neural mechanisms of contour grouping and figure-ground organization.

5 Figure-Ground Organization

5.1 introduction.

Two adjoining regions of the visual field with a shared border can lead to a mosaic percept, but more often it leads to figure-ground organization. In this percept, the shared border is perceived as the occluding edge of one of the regions. The occluding region is perceived as the figure, and it appears shaped by the border. The adjoining region appears to simply continue behind it as its background, with no shape being imparted by the border. The figure is said “to own the borderline.” When figure-ground reversals occur, the border-ownership switches as well (e.g., the famous vase-faces figure by Rubin, 1915 ). Why switching occurs and how its temporal characteristics inform us about the dynamics of the brain is discussed extensively in the second paper ( Wagemans et al., 2012 ; Section 3). Here, we focus on the factors or principles that determine what is perceived as figure.

The question of whether or not experience plays a role has been particularly controversial. On the one hand, structuralists like Wundt argued that past experience was the sole determinant of which region of the visual field was perceived as figure. On the other hand, Gestalt psychologists like Wertheimer, Koffka, and Köhler, considered the structuralist position untenable because it would draw too strongly on memory to be useful for real-time perception. They also pointed out that novel objects can be perceived easily, which is inconsistent with a theory in which only past experience causes perceptual organization. The Gestalt view was that figure-ground segregation occurs by innate, intrinsic segregation laws that embody aspects of the world in which human perception evolved. The resultant shaped entities (figures) are then matched with traces in memory, a process that requires a less extensive memory search. In this view, familiar and novel objects are distinguished only after they attain figural status.

Wertheimer argued that past experience was unlikely to influence initial organization. He put forward two requirements to be met for past experience to convincingly play a role in figure-ground perception ( Wertheimer, 1923/1938 , p. 86): “[The] duty [of the doctrine of past experience] should be to demonstrate … (1) that the dominant apprehension [perception] was due to earlier experience (and to nothing else); (2) that nondominant apprehensions in each instance had not been previously experienced.” The Gestalt psychologists demonstrated that a variety of image properties were sufficient for the perception of figures or configurations, without the need of familiarity. These image properties—convexity, symmetry, small area, and “surroundedness” (or enclosure)—became known as the classic configural principles of figure-ground organization (e.g., Harrower, 1936 ; Rubin, 1915 ).

5.2 Classic Image-Based Configural Principles of Figure-Ground Organization

Traditionally, investigators have tested the effectiveness of configural factors in controlled experiments, using displays composed of multiple alternating black and white regions where either the black or the white region could have the configural factor (e.g., convexity in Figure 17 ). Participants were asked to indicate which region, the black or the white one, was perceived as the figure. These experiments support less formal early demonstrations of the importance of configural factors for initial figure-ground segregation, without the need to rely on past experience (familiarity). The most powerful demonstrations were obtained with convexity and symmetry, although these principles were often confounded in earlier studies (e.g., Bahnsen, 1928 ). Confounding often occurred in tests of the other two configural principles—small region and surroundedness—as well, which created some confusion on the individual effectiveness of each of these principles. Note that long exposure times were used in these early demonstrations, so it is not clear that reports reflected initial organization. Later, more controlled investigations of convexity and symmetry revealed that their strength was overestimated by traditional demonstrations.

Example of a display used in classic tests of whether or not convexity serves as a configural figure-ground principle. Here the black regions have convex parts, and the white regions have concave parts. Regions with convex parts were black in half of the test displays and white in the other half. Adapted from Peterson and Salvagio (2008) , with permission.

Also using long exposures, Kanizsa and Gerbino (1976) , tested the effectiveness of convexity as a configural figure-ground principle, using displays similar to Figure 17 , and found that regions with convex parts were seen as figure on approximately 90% of trials. These results—in tandem with the previous Gestalt demonstrations—were taken as evidence that part convexity might determine to a large extent the position of figures in the input array, even before memories of previously seen objects are accessed (see Singh & Hoffman, 2001 ). To examine whether the effects of part convexity are general in that they extend to stimuli with fewer regions than used in the original displays, Peterson and Salvagio (2008) presented displays that could contain either two, four, six, or eight regions. In addition, the exposure duration was reduced to 100 ms. Interestingly, the likelihood of perceiving convex regions as figures increased from only 57% of trials with two-region displays, up to 89% for eight-region displays (as in Kanizsa & Gerbino, 1976 ). This effect of the number of alternating regions—the convexity context effect—was obtained only when the concave regions were homogeneous in color, whereas the color of the convex regions was irrelevant. Thus, homogeneity of alternating regions functions as a background cue, but other experiments indicated that it does so only when a configural cue favors perceiving the regions in-between as figures. These experimental observations are consistent with a Bayesian ideal observer model that estimates the probability that a picture depicts a 3-D scene or a 2-D pattern ( Goldreich & Peterson, 2012 ). Specifically, to be able to fit Peterson and Salvagio’s (2008) data, the Bayesian observer had weak biases for convex over concave objects and for single-color over multi-color occluded objects.

Kanizsa and Gerbino (1976) measured the effectiveness of global symmetry as a configural figure-ground principle by placing it in competition with convexity. They found that convex-region-as-figure reports were unaffected by competition from symmetry, suggesting that symmetry is only a weak factor (see also Pomerantz & Kubovy, 1986 ). However, with longer exposures of eight-region displays consisting of alternating symmetric and asymmetric regions (with no competition from convexity), Driver, Baylis, and Rafal (1992) found that symmetric regions were perceived as figures on a large proportion of the trials. When Peterson and Gibson (1994a) examined the effectiveness of symmetry as a configural figure-ground principle in two-region displays with brief exposure durations, their observers reported perceiving the symmetric region as figure on approximately three-quarters of the trials. Effects of global symmetry have also been found for shapes defined by a contour of Gabor elements presented in a noisy background ( Machilsen et al., 2009 ), suggesting that global symmetry is effective in segregating figures from backgrounds. Together, these findings are consistent in showing that—at least near fixation—global symmetry is a configural figure-ground principle.

5.3 New Image-Based Principles of Figure-Ground Organization

All of the above classic figure-ground principles concern the organization of displays consisting of static, homogeneously colored regions. Quite a few additional principles of figure-ground organization have since been discovered, some of which also apply to static, homogeneously colored regions (e.g., lower region, and top-bottom polarity). Additional figure-ground principles come into play in displays containing spatial heterogeneities such as texture (extremal edges and edge-region grouping) and when they contain motion (advancing region, articulating concavities, and convex motion). Pinna (2010) recently even extended the range of application of these principles to shape and meaning. As with the new grouping principles, researchers have often provided an ecological foundation of these new figure-ground principles too.

Lower region

Vecera, Vogel, and Woodman (2002) showed that when a rectangular display is divided in half by an articulated horizontal border, the region below the border is more likely to be perceived as the closer, figural region than is that above the border. They found this lower-region bias most strongly in “city-scape” images in which the border consisted of horizontal and vertical segments, but also in analogous “stalactite/stalagmite” images consisting of curved segments. Vecera (2004) performed additional experiments in which such displays were viewed by observers whose heads were tilted (or even inverted) to determine whether this figure-ground bias was driven by a viewer-centered, retinal reference frame or an environmental reference frame. The results showed—somewhat surprisingly—that retinal directions were clearly dominant. Although this result is at odds with the presumed ecological justification of gravity as the rationale for perceiving lower regions as closer (see Vecera & Palmer, 2006 ), it is consistent with the need to compute information about figure-ground status early in visual processing, before orientation constancy has occurred. Indeed, because head orientation is approximately vertical most of the time, the difference between retinal and environmental reference frames is negligible. The ecological validity of lower region was assessed statistically by analyzing a corpus of photographic images that were hand-segmented by human observers ( Martin, Fowlkes, Tal, & Malik, 2001 ). The results showed that lower region was a valid cue to closer surfaces at local edges whose orientation was roughly horizontal. Vecera and Palmer (2006) argued that the effect of seeing lower regions as closer resulted from biases in the ecological statistics of depth edges at various orientations when objects rest on a ground plane beneath them, as do most terrestrial objects in the earth’s gravitational field.

Top-bottom polarity

Hulleman and Humphreys (2004) showed that regions that are wider at the bottom and narrower at the top are more likely to be perceived as figures than regions that are wider at the top and narrower at the bottom. The regions in their displays looked a bit like odd evergreen trees or chess pieces, but they argued that their effects were not due to the effects of familiar shape (e.g., Peterson & Gibson, 1994a ) because there are other familiar objects (e.g., tornados) that are similar in shape to the regions with narrow bases and wide tops. They also claim that top-bottom polarity effects cannot be explained by the effects of lower region ( Vecera et al., 2002 ). Nevertheless, the ecological factor that links all three of these figure-ground factors (canonical orientation of familiar shapes, lower region, and top-bottom polarity) is gravity. Indeed, top-bottom-polarity can easily be interpreted as due to the perceptual consequences of gravitational stability.

Extremal edges and gradient cuts

An extremal edge (EE) in an image is a projection of a viewpoint-specific horizon of self-occlusion on a smooth convex surface, such as the straight side of a cylinder. Computational analyses of the visual properties of surfaces near EEs show characteristic gradients of shading and/or texture in which the equiluminance and/or equidensity contours are approximately parallel to the edge of the surface ( Huggins & Zucker, 2001 ). EEs are relevant to figure-ground determination because the side with an EE gradient is almost invariably perceived as being closer to the observer than the opposite side of the edge ( Palmer & Ghose, 2008 ), even when EE is placed in conflict with other factors ( Ghose & Palmer, 2010 ).

Edge-region grouping

Palmer and Brooks (2008) built a bridge between classic grouping effects and figure-ground organization by reasoning that if figure-ground organization is indeed determined by an edge “belonging to” (i.e., grouping with) the region on one side more strongly than that on the other, then any grouping factor that could relate an edge to a region should also operate as a figure-ground factor. They tested this hypothesis for six different grouping factors that were well-defined for both an edge and a region—common fate, blur similarity, color similarity, orientation similarity, proximity, and flicker synchrony—and found that all six factors showed figure-ground effects in the predicted direction, albeit to widely varying degrees.

Articulating motion

Barenholtz and Feldman (2006) demonstrated a dynamic principle of figure-ground organization: When a contour deforms dynamically, observers tend to assign figure and ground in such a way that the articulating (or hinging) vertices have negative (concave) curvature—which ensures that the figure side is perceived as containing rigid parts articulating about their part boundaries. In their experiments, this articulating-concavity bias was shown to override traditional static factors (such as convexity or symmetry) in cases where they made opposing predictions. In other experiments, Barenholtz (2010) showed that when a contour segment that is concave on one side and convex on the other deforms dynamically, observers tend to assign the figure on the convex rather than the concave side.

Advancing region motion

Barenholtz and Tarr (2009) showed that moving a border within a delimited space such that the bounded area on one side grows larger and the bounded area on the other side shrinks in size causes the growing area to be perceived as a figure advancing onto the shrinking area. Thus, motion in an advancing region overpowers the classic Gestalt factor of small area.

Contour entropy as a determinant of ground or hole

All of the above research is aimed at finding factors that determine the perception of a figure against a background. Gillam and Grove (2011) recently asked whether there are also factors that strengthen the perception of a region as ground. They reasoned that occlusion by a nearer surface will usually introduce a regularity among terminations of contours at the occluding edge, which will be perceived as a stronger cue to occlusion when the irregularity of the elements is higher. In other words, when the lines being terminated are more disordered, the strength of the occlusion cue (called “order within disorder” or “entropy contrast”) is larger. They predicted that unrelated (high entropy) lines would tend to appear as ground (or “holes”) in a figure-ground paradigm more often than more ordered (low entropy) lines, which was confirmed in three experiments. This work significantly expands earlier work on the perception of holes (e.g., Bertamini, 2006 ; Bertamini & Hulleman, 2006 ; Nelson & Palmer, 2001 ).

5.4 Nonimage-Based Influences on Figure-Ground Perception

5.4.1 past experience.

For most of the 20 th century, the Gestalt view that past experience did not influence initial figure-ground perception prevailed. Part of the reason for this continued view might have been that few direct tests existed of the influence of past experience on figure-ground perception that satisfied Wertheimer’s (1923) criteria mentioned above. Either there was no evidence that past experience alone drove the effect, or it was possible that past experience exerted its influence after the initial perceptual reorganization. Other observer-dependent factors such as perceptual set and attention were also assumed to be high-level influences, operating only after figures had been segregated from grounds. Recently, evidence that past experience can influence figure assignment has accumulated both from direct report and indirect, response time measures.

Direct reports

Using direct report measures, Peterson, Harvey, and Weidenbacher (1991 ; Peterson & Gibson, 1994a ) found that regions that portrayed portions of familiar objects were more likely to be perceived as figures when they were upright (and hence, portrayed the familiar object in its canonical orientation) than when they were inverted (see Figure 18 ). Importantly, regions portraying upright, but not inverted, familiar objects were more likely to be obtained as figures by reversing out of the alternative interpretation, suggesting that past experience in the form of familiar configuration exerts an influence on the initial determination of figure and ground ( Gibson & Peterson, 1994 ; Peterson et al., 1991 ; Peterson & Gibson, 1994a , 1994b ).

(A–B) Sample stimuli used by Peterson et al. (1991) . The configural factors of small area, symmetry, and enclosure favor seeing the central, black region as figure. In A, a portion of a familiar object, a standing woman, is suggested on the outside of the left and right borders of the black region. B is an inverted version of A. (C–D) Sample upright (C) and inverted (D) bipartite displays used by Peterson and Gibson (1994a) . (E–G) Sample stimuli used by Peterson and Skow (2008) . The configural factors of small area, symmetry, and enclosure favor seeing the inside of the black silhouettes as the figures. Portions of familiar objects re suggested on the outsides of the silhouettes' left and right borders (in E, sea horses; in F, table lamps; in G, pineapples). Adapted with permission.

The stimuli used in these studies most likely satisfied Wertheimer’s first criterion for evidence of past experience effects on figure assignment. However, it was—and still is—difficult for experiments that measure subjects’ phenomenal reports to satisfy his second criterion (to exclude that past experience exerts its influence after some initial perceptual reorganization). Even with masked exposures as short as 28 ms, such as those used by Peterson and Gibson (1994a) , it is still possible that some preliminary, unconscious, figure-ground determination preceded the organization about which observers reported ( Epstein & DeShazo, 1961 ), introducing the need for an indirect or implicit measure.

Indirect measures

Driver and Baylis (1996) were the first to use reaction time measures to index figure-ground perception in an experiment in which subjects were shown a brief exposure of a display containing a small high contrast region lying on a larger rectangle. In this stimulus configuration, both contrast and the configural factor of small area biased participants to see the small region as figure ( Figure 19A ). On each trial, participants were asked which of two small, enclosed test shapes shown after the initial display had the same border as the stepped border dividing the rectangle into two regions. On half of the test trials, the test shape lay on the same side of the border as the region that was likely to have been perceived as figure (“figure” probes; Figure 19B ), whereas on the remainder of the test trials, the test shape lay on the opposite side (“ground” probes; Figure 19C ). Faster and more accurate responses were obtained on figure test trials than on ground test trials, suggesting that the border shared by two regions in the initial display was automatically bound to the one cued as figure. (For later use of Driver and Baylis’ indirect measure, see Hulleman & Humphreys, 2004 ; Vecera, Flevaris, & Filapek, 2004 .)

Driver and Baylis (1996) also interpreted the results they obtained with their indirect measure to indicate that past experience does not influence figure assignment, reasoning that response times should be equally fast for figure and ground probes if past experience were operating. Peterson and Enns (2005) , however, argued that this reasoning was flawed and that a past experience account could also predict the pattern of results obtained on ground test trials by Driver and Baylis (see also Peterson & Lampignano, 2003 ). This is because the repetition of the border from the first trial would reinstantiate the memory of where the figure lay when the border was first encountered, and this memory would compete with the current cues favoring the figure on the opposite side of the border. This competition would slow responses on ground test trials compared to figure test trials. Peterson and Enns introduced control test trials to investigate this alternative interpretation. They asked subjects to ignore the first display and then to decide for a second display, whether the pair of small closed figures it contained was identical (as a consequence, the first display served as a priming display). Consistent with the past experience account, response times were slower on ground test trials (and faster for figure test trials) compared to control trials facing in the same direction.

Further evidence for the role of past experience in figure-ground perception was obtained by Vecera and Farah (1997) , who presented observers with overlapping outline letters and asked them to determine whether two probed locations were on the same letter or on different letters, a distinction that depended on figure-ground organization. Congruent with an influence of past experience, faster and more accurate responses were obtained when the outline letters were in their familiar upright orientation rather than inverted. Peterson and Skow (2008) went one step further using displays like those in Figure 18E-G , in which shape properties such as small area, enclosure, and symmetry strongly favored perceiving the figure on the inside of a silhouette’s borders, but past experience favored seeing the figure on the outside. The stronger factors favoring the figure on the inside dominated the competition for figural assignment. Nevertheless, responses to the familiar object that lost the competition were suppressed for a brief period of time after figure-ground perception was achieved, providing evidence that past experience plays a role in figure-ground segregation even when it does not dominate (see also Trujillo, Allen, Schnyer, & Peterson, 2010 , for a study measuring the associated event related potentials). Recently, Navon (2011) conducted a series of experiments that he took as evidence that the familiarity of objects may exert an influence even earlier, when pre-figure assignment parsing occurs.

Taken together, these findings from studies that satisfy both of Wertheimer’s (1923) criteria show that past experience can exert an influence on several aspects of figure-ground perception.

5.4.2 Attention and perceptual set

Before any behavioral evidence was obtained that attention affects which region will be perceived as figure, Kienker, Sejnowski, Hinton, and Schumacher (1986 ; Sejnowski & Hinton, 1987 ) modeled figure-ground segregation as cross-border inhibitory competition that could be biased by attention. A decade later, Baylis and Driver (1995) presented empirical evidence for the role of attention. They found that when observers allocated their attention endogenously to one of two regions sharing a border, they were more likely to perceive the attended region as figure than the unattended region. Similar, but weaker effects of exogenous attention were later obtained ( Vecera et al., 2004 ). In addition, it has been shown that the viewer’s intention, or perceptual set, to perceive one of two regions sharing a border as figure can influence figure assignment ( Peterson et al., 1991 ; Peterson & Gibson, 1994b ). Thus, there is ample evidence that observer-dependent factors can influence figure assignment.

The effects of attention and perceptual set contradict claims that figure-ground perception always occurs “early” in the visual system. Indeed, although figure-ground perception can be affected by focused attention, there is evidence that it can also occur preattentively. Preattentive processes are considered “early” in that they are carried out before attention is focused on individual regions in the visual field, that is, when attention is either distributed broadly or allocated to a different task. For example, in a case study of a patient with left neglect (a failure to attend to the left side of objects and spaces), it was found that judgments of the symmetry of individual shapes in the left hemisphere were severely impaired ( Driver et al., 1992 ). Nevertheless, when asked to make figure-ground judgments regarding six-region displays with green and red alternating symmetric and asymmetric regions, the patient, like controls, showed a bias to see symmetric regions as figures, suggesting that the patient could use symmetry preattentively for figure-ground segregation even though he could not detect it postattentively. Convexity-based figure-ground segregation can also occur preattentively. Kimchi and Peterson (2008) asked participants to perform a demanding change detection task on a stimulus presented on a task-irrelevant background of alternating regions of figures and grounds by convexity. They found that changes in the organization of the background produced congruency effects on target-change judgments, even though participants were unable to report the figure-ground status of the background. Taken together, these findings are consistent with the claim that figure-ground segregation can occur before focal attention is directed to making a figure-ground judgment. Thus, figure-ground segregation can occur preattentively, but it can also be affected by attention.

5.5 Figure-Ground Organization in Relation to Shape and Depth Perception

Traditionally, figure-ground organization has been studied as a relatively isolated, albeit important aspect of perceptual organization. Studies like those reviewed above, however, have clearly shown that figure-ground organization is closely related to other aspects of visual perception like shape and depth perception.

5.5.1 Shape perception

Consider the following demonstration due to Attneave (1971) : A random wiggly contour is drawn across a disk, dividing it into two, and the two half-disks are spatially separated ( Figure 20 ). Even though the contour is—by construction—identical on the two halves, it looks different. The wiggly contour on the left half-disk appears to contain three wide, smooth parts, whereas on the right, it appears to contain four narrow, pointy parts. This demonstration suggests that the visual system assigns shape descriptions to surfaces, rather than to the bounding contours of those surfaces: Even when instructed to judge a contour in isolation, observers cannot help but be influenced by the geometry of the surface to which the contour belongs. Hence, shape description is closely tied to figure-ground assignment.

When a wiggly curved line is drawn on a circular disc, the two halves arising from this divide appear to have a bounding contour with a different shape (adapted from Attneave, 1971 ).

One account of how these processes interact was offered by Hoffman and Richards (1984) . They proposed that the visual system segments objects into parts at points of negative minima of curvature (points of locally highest curvature in concave regions) along the bounding contour of the shape. According to this minima rule, the same wiggly contour in Figure 20 is segmented differently on the two half-disks because, when figure and ground switch, so do the roles of convexities and concavities. Hence perceptual part boundaries—which lie in concavities—are located at different points on the two halves (marked with the dots in Figure 20 ). The contour is perceptually segmented into parts differently on the two half-disks—hence it looks different. This account of part segmentation has been supported in a number of experiments (e.g., Barenholtz & Feldman, 2006 ; Baylis & Driver, 1994 ; Cohen & Singh, 2007 ; De Winter & Wagemans, 2006 ; Singh & Hoffman, 2001 ).

Building on this account, Hoffman and Singh (1997) proposed that the relative salience of the two sets of parts, one at each side of the borderline, plays an important role in determining figure and ground. (In this respect, it could be considered one of the new image-based principles of figure-ground organization reviewed before.) The perceptual salience of a part, or part salience for short—how much it visually stands out as a separate part—is determined by a number of geometric factors, including the curvature (“sharpness”) of its part boundaries, and its protrusion (the degree to which it “sticks out,” measured as perimeter/cut length). Typically, the side with the more salient parts is assigned figural status, as illustrated in Figure 21 . In this figure, (a) shows the original contour, (b) shows the parts obtained from the two sides, and (c) shows the side with more salient parts, which tends to be perceived as figure. Because part salience is based on relatively local computations, figure and ground can perceptually reverse along a continuous contour (see Figure 21D ). This suggests that shape analysis occurs not only on the figure side— after figure-ground assignment has taken place—but actually precedes it, and it plays a crucial role in making the figure-ground assignment. This account is consistent with previous proposals made by Peterson and colleagues discussed before, although it involves only low-level shape analysis, and does not posit access to memories of familiar shapes.

The role of part salience in figure-ground organization (adapted from Hoffman & Singh, 1997 , with permission).

Another way of thinking about this shape analysis is in terms of a skeletal or axial representation of shape. (Hence, axiality could also be added to the list of new image-based principles of figure-ground organization.) Skeletal or axial representations provide a compact “stick figure” representation that reflects the qualitative branching structure of a shape ( Blum, 1973 ; Leyton, 1989 ; Marr & Nishihara, 1978 ). In a recent probabilistic model of shape skeletons ( Feldman & Singh, 2006 ), the “goodness” of a skeleton—formally, its posterior pr(Skeleton|Shape)—is evaluated in terms of (i) how well the skeleton explains the shape—its likelihood pr(Shape|Skeleton); and (ii) its simplicity—the prior pr(Skeleton) which embodies a preference for fewer branches and less curved branches. The “best” skeleton (that maximizes the posterior) provides an intuitive summary description of the shape, and allows a one-to-one correspondence between its skeletal branches and the parts of the shape. The skeletal model of shape description applies to the figure-ground context as follows: The skeleton is computed from both sides of the contour, yielding skeletal descriptions of the surface on either side; and whichever side has a more “axial” shape (higher posterior) wins the figure-ground competition. A recent Bayesian implementation of this competition has been shown to closely resemble human perception of figure and ground ( Froyen et al., 2010 ).

5.5.2 Depth perception

Because the figure is by definition closer to the observer than the ground, figure-ground organization is necessarily related to certain aspects of depth perception. One can think of figure-ground principles as a subset of sources of depth information that apply to the special case of inferring relative (i.e., ordinal) depth across an edge. Recently, the seemingly ordinal figure-ground factor of convexity was found to combine with classic metric depth cues, such as binocular disparity ( Burge, Peterson & Palmer, 2005 ), suggesting that it might be a metric rather than an ordinal depth cue. Indeed, in a recent study of natural scene statistics, Burge, Fowlkes, and Banks (2010) concluded that convexity is a metric cue to depth. Many questions remain regarding how figural cues signal depth.

5.6 Conclusion

Research on figure-ground organization has also come a long way since Wertheimer’s (1923) paper on the Gestalt laws. First, when studied in more controlled experiments, the classic, configural principles turn out weaker than previously supposed. Second, using richer displays, new figure-ground principles have been discovered with a plausible ecological foundation. Third, the role of past experience and attention has now been clearly demonstrated in experiments that satisfy Wertheimer’s own criteria. Finally, figure-ground organization is no longer studied in isolation but turns out to be intimately related other processes such as shape and depth perception. These connections are currently also the focus of interesting research on the neural mechanisms of contour grouping and figure-ground organization, as reviewed next.

6 Neural Mechanisms in Contour Grouping, Figure-Ground Organization, and Border-Ownership Assignment

6.1 introduction.

Recall that the failure of the experiments by Lashley et al. (1951) and Sperry et al. (1955) to support key predictions of Köhler’s electromagnetic field theory of brain function was a devastating blow to Gestalt theory’s attempt towards a radically different understanding of the brain mechanisms that underlie perception and cognition. The dominant model of brain function since then has been that the brain consists of an architecture of organized, interconnected neurons that interact via synaptic communication to form complex circuits that respond selectively to different properties of visual stimulation. Building on Hubel and Wiesel (1968) ’s discovery and characterization of four types of neurons in the primary visual cortex (concentric, simple, complex and end-stopped), and the large number of neurophysiological studies that followed since then, the current view of the visual system is that of a hierarchy of stages of gradually increasing scale and complexity of processing, paralleled by the increasing receptive field size and increasing selectivity of neurons across the sequence of cortical areas in the “ventral stream” (see Rust & DiCarlo, 2010 , for a quantitative study).

It may seem that such a conception is fundamentally incompatible with Gestalt notions of brain function, but this is untrue. First, there is some evidence against such a strict hierarchical organization. For instance, measurements of receptive field size tend to underestimate the influence of context in neurons at the low levels, as many studies of so-called non-classic surround influences have shown ( Allman, Miezin, & McGuinness, 1985 ; for further references, see Alexander & van Leeuwen, 2010 ; Angelucci et al., 2002 ). Second, and more fundamentally, there is a more abstract level at which a Gestalt conception of brain function might be correct even if Köhler’s conjecture about its implementation in dynamically converging electromagnetic brain fields is not. It is now clear that recurrent networks of neuron-like elements—networks that contain closed feedback loops—are a much more plausible implementation of the hypothesis that the brain is a physical Gestalt. Physicist John Hopfield (1982) clarified this possibility when he proved that symmetric recurrent networks—networks with equal weightings in both directions between any pair of units—will always converge to an equilibrium state that satisfies an informational constraint isomorphic to minimum energy in physics. Hence, the Gestaltists may have been wrong in detail about the brain being an electromagnetic Gestalt system, but they may still have been correct at a more abstract level if recurrent networks are found to be crucial for perceptual organization. Important models of organizational phenomena within recurrent networks have indeed been proposed by Grossberg and others (e.g., Grossberg & Mingolla, 1985 ; Kienker et al., 1986 ). Furthermore, while neurophysiological models for contour integration based upon good continuation principles have been based primarily upon cortical networks in area V1 ( Li, 1998 ; Roelfsema, 2006 ; Yen & Finkel, 1998 ), as well as recurrent interactions between areas V1 and V2 ( Neumann & Sepp, 1999 ), fMRI studies of contour grouping in both human and macaque implicate not only V1 and V2 but other extrastriate visual areas such as V4 and LOC (e.g., Altmann, Bülthoff, & Kourtzi, 2003 ; Kourtzi, Tolias, Altmann, Augath, & Logothetis, 2003 ).

Rather than providing a list of putative neural correlates of all the Gestalt principles, this section reviews neurophysiological studies investigating the neural mechanisms in contour grouping, figure-ground organization, and border-ownership assignment in an integrated way. In doing so, we demonstrate how contemporary neuroscience has embraced Gestalt ideas, while doing justice to Hubel and Wiesel’s heritage in the following three ways: (1) We demonstrate how the responses of cortical neurons can depend on the parameters of the stimulus in its receptive field as well as on the properties of the overall configuration in the visual field; (2) we substantiate the Gestalt postulate of autonomous organization processes that form primary units of perception; and (3) we refine our understanding about the role of attention in these processes of perceptual organization.

6.2 Context Integration in Illusory Contours

Illusory contours were among the earliest demonstrations of perceptual organization ( Schumann, 1900 ). Gestalt theory explains these contours by completion processes in the visual cortex. Initially, Sillito and colleagues (discussed in Gregory, 1987 ) recorded single neuron responses in cat primary visual cortex and found no evidence for illusory contour signals. Neurons that clearly responded to low-contrast figures were silent when illusory figures with the same perceived contrast were presented. However, recording from an area one level higher, namely in V2 of the monkey visual cortex, von der Heydt, Peterhans, and Baumgartner (1984) found illusory contour responses in about one third of the recorded neurons. The stereotyped nature of the responses to repeated stimulation and their short latency indicated that the observed responses were stimulus-driven rather than resulting from higher-level, cognitive predictions as hypothesized by Gregory (1972) .

Coren (1972) noticed that illusory contours generally arise in situations that suggest occlusion. One of the many models that have been proposed to explain illusory contours proposes that the V2 responses reflect a general mechanism for the detection of occluding contours ( Heitger, von der Heydt, Peterhans, Rosenthaler, & Kübler, 1998 ; Peterhans & von der Heydt, 1989 ). Under natural conditions, objects often occlude one another, and detecting the borders between image regions corresponding to foreground and background objects is a basic task of vision. V2 mechanisms might combine two sources of evidence for occluding contours: the presence of a luminance/color edge and the presence of occlusion features along the contour. Luminance/color differences can be detected by simple and complex cells and occlusion features (i.e., terminations of background structures) by end-stopped cells ( Heitger, Rosenthaler, von der Heydt, Peterhans, & Kübler, 1992 ). By integrating inputs from simple/complex cells and appropriately selected end-stopped cells, V2 neurons can signal occluding contours more reliably than mechanisms based on edge detection alone ( Heitger et al., 1998 ).

This model can be considered as a simple implementation of the Gestalt completion principle according to which illusory contours are formed in situations in which unbalanced shapes tend to completion ( Kanizsa, 1979 ; Michotte et al., 1964 ). For example, the contours of an illusory white square in a configuration with four black pacmen are thought to emerge because the disc sectors tend to complete to circular discs (see Figure 22A ). In the model, the terminations of the circular edges activate end-stopped cells. This mechanism allows for the possibility that the terminations are caused by occlusion and that the edges might continue in the background. While the principle of combining edge evidence with evidence from occlusion features for the definition of contours is valid, the model might be too simplistic because it fails to account for illusory contour perception in stereoscopic displays ( Gillam & Nakayama, 2002 ). Also, models of illusory contours in Kanizsa figures should be able to explain why the illusion disappears in other configurations (e.g., four crosses instead of four pacmen; see Figure 22B ), which is a clear indication of the important role of the whole stimulus configuration, in line with the basic tenets of Gestalt psychology (see Kogo, Strecha, Van Gool, & Wagemans, 2010 , discussed further in the next section).

In a configuration with four black pacmen, an illusory white square emerges in the center, which does not happen when the same local edges occur in a configuration with four black crosses.

6.3 Figure-Ground Organization and Border-Ownership Assignment

The mechanism of illusory contours has obvious spatial limits: Illusory contours disappear when gaps become larger than a few degrees of visual angle ( Peterhans & von der Heydt, 1989 ). However, the spatial range at which figure-ground organization occurs is impressive, given the small receptive fields in the visual cortex. Even the extent of the nonclassic surrounds, which is typically about twice the size of the classic receptive field (see Cavanaugh, Bair, & Movshon, 2002 ; Levitt & Lund, 2002 ), is insufficient to explain the spatial range of figure-ground organization. It was therefore a surprise when Lamme (1995) discovered that neurons in monkey V1 show enhanced responses in figure regions compared to ground regions (see also Lee, Mumford, Romero, & Lamme, 1998 ; Zipser, Lamme, & Schiller, 1996 ). The figures in these studies were defined by a difference in texture, which could be based on orientation, motion, depth, or color, suggesting a general mechanism. Although the figure-ground modulation decreased with figure size and disappeared for figures larger than 8°, the range of context integration was clearly much larger than the typical size of the receptive fields (but see Rossi, Desimone, & Ungerleider, 2001 ).

While Lamme’s (1995) finding suggests coding in terms of regions, perceptual studies also emphasize the distinctive role of the borders between regions. Bregman (1981) has published a striking demonstration of this: Figure 23(a) shows a number of apparently meaningless shapes, while (b) shows exactly the same shape fragments, but with a blotch of ink present which is removed in (a). Because the blotch is seen as a foreground object, it takes ownership of some of the borders of the original shapes, which now organize to letters due to amodal completion of the shape fragments behind the blotch. The crucial role of border-ownership in image interpretation was rediscovered by Nakayama, Shimojo, and Silverman (1989) and it was also recognized in computational modeling studies ( Finkel & Sajda, 1992 ) but how border-ownership might be coded by neurons was less clear until recordings from monkey visual cortex by Zhou, Friedman, and von der Heydt (2000) revealed that the firing rate of orientation-selective neurons that respond to the contours of figures depended on where the figure is located relative to the receptive field of the neurons. Moreover, each neuron was found to have a fixed preference for direction of figure, while across neurons all directions in the visual field were represented equally. As a consequence, each border is represented by two groups of neurons, one for each side of ownership. Zhou et al. suggested that the differential activity between the two represents the border-ownership assignment. In area V2, about half of the oriented neurons are border-ownership selective. Such neurons can also be found in V1 and V4, but less frequently.

(a) A quasi-random collection of quasi-random shapes. (b) The same shapes as in (A) with a black ink blotch, which is seen to occlude five letters ‘B’ (adapted from Bregman, 1981 ).

Two characteristics of border-ownership coding are remarkable: the large range of context integration and the short latency of the differential response. The context influence extends far beyond the classic receptive field, and it appears less than 30 ms after the earliest responses in V1 or V2 (60–70 ms after stimulus onset), which is earlier than the figure-ground enhancement in V1 ( Lamme, 1995 ). Tests with fragmented figures showed that most or all segments of the figure contours contribute ( Zhang & von der Heydt, 2010 ). These findings have strong implications for possible neural mechanisms, in particular for the role of horizontal interactions, which is often postulated in models of figure-ground organization (e.g., Finkel & Sajda, 1992 ; Grossberg, 1994 ; Kogo et al., 2010 ; Sajda & Finkel, 1995 ; Zhaoping, 2005 ). Close examination of the conduction delays shows that the horizontal propagation scheme is incompatible with the large range of context integration and the short latency of the context influence ( Zhang & von der Heydt, 2010 ; for a discussion, see Craft, Schütze, Niebur, & von der Heydt, 2007 ). There is little evidence for propagation delays in context integration for border-ownership. Instead, Zhang and von der Heydt found that the influence of the most distant contour segments arrived earlier than that of the segments closest to the receptive field. Hence, it is more likely that context integration involves feedback from higher-level visual areas (e.g., Craft et al., 2007 ; Jehee, Lamme, & Roelfsema, 2007 ; Roelfsema, Lamme, Spekreijse, & Bosch, 2002 ): Neurons in these areas have larger receptive fields and signals between areas travel through white matter fibers which are much faster than the intracortical horizontal fibers. These models are in agreement with studies showing that the far surround of receptive fields in V1 is contributed by feedback ( Angelucci et al., 2002 ).

The involvement of border-ownership and feedback in figure-ground organization have much to say about its relevance in everyday vision. Figure-ground organization is obviously related to the task of interpreting 2-D images in terms of a 3-D world, which is fundamental to vision. What Gestalt psychology has revealed is the compulsion of the system to seek a 3-D interpretation, even under the impoverished conditions of simple drawings that do not provide information about depth. When explicit depth information is available, for example in stereoscopic vision, it has a profound influence on image segmentation and perceptual organization ( Gregory & Harris, 1974 ; Nakayama et al., 1989 ; Shimojo, Silverman, & Nakayama, 1989 ). The influence of stereoscopic depth is an important criterion for the validity of the interpretation of the neural signals. If response enhancement and border-ownership modulation indeed participate in the attempt to fit a 3-D interpretation, then these signals should respond to border-ownership given by disparity as well as by 2-D cues, but if they reflect general receptive field mechanisms (e.g., center-surround antagonism), there would be no reason for this parallelism. Several neurophysiological studies have shown that stereoscopic depth can indeed dramatically influence the cortical responses to a visual stimulus, even in early visual regions ( Bakin, Nakayama, & Gilbert, 2000 ; Duncan, Albright, & Stoner, 2000 ; Qiu & von der Heydt, 2005 ; Zipser et al., 1996 ).

For instance, applying Lamme’s figure-ground paradigm to random-dot stereograms, Zipser et al. (1996) showed that the enhancement is not simply the result of surroundedness, but depends on the conditions of figure perception. When a surface in the fixation plane (zero disparity) is surrounded by a region of “far” disparity, it assumes figure status and produces enhancement of responses; it appears as an object floating in front of a background. In contrast, when it is surrounded by “near” disparity, it assumes ground status and no enhancement occurs; the surrounded region now appears as a surface in the back that is seen through a window. Stereoscopic depth also has a strong influence on the coding of border-ownership. Qiu and von der Heydt (2005) found that many V2 cells combine border-ownership selectivity (for contrast-defined figures without disparity) with stereo-edge selectivity in random-dot stereograms, and the preferred side of the figure was generally the same as the preferred foreground side in the stereograms. This means that the cortex interprets a contrast defined figure as an object occluding a background, in line with the Gestalt view.

The above findings have recently been integrated in a neuro-computational model ( Kogo et al., 2010 ) in which border-ownership and occlusion play a central role in the emergence of illusory surfaces and contours in Kanizsa-type displays (see Figure 22 again). Specifically, local occlusion cues (L- and T-junctions) trigger a perceived depth difference and border-ownership signals at the visible edges, which then spread and combine with border-ownership signals in the open space between the pacmen. This spreading and enhancement of border-ownership only occurs with particular global configurations of the visible elements (the pacmen) that are consistent with a central surface (e.g., not in the four-crosses configuration). In contrast with many previous models, this model is not aimed at contour completion based on the collinearity of the local image fragments. Instead, it achieves surface completion triggered by local depth cues that are consistent with a particular global configuration, which is more in line with the original Gestalt view of the phenomenon. Moreover, it treats the neural responses by V1 cells not as feature detectors but as 2-D differentiated signals. These signals are then spatially integrated in 2-D surfaces, allowing a reinterpretation of well-known facts from single-cell recordings into a more global, functional, perceptual framework in the Gestalt tradition.

6.4 Involuntary Organization and Volitional Attention

The classic Gestalt psychologists demonstrated the existence of an early, autonomous process of visual organization, producing percepts that do not always conform to previous knowledge or expectations about the stimulus. Small changes to the stimulus can induce extensive perceptual reorganization. For example, a display consisting of two light and two dark squares on a medium gray background (see Figure 24b ) can easily be turned into a display that looks like two crossed bars, one light and one dark, in transparent overlay (see Figure 24c ), when the corners are made sharp instead of rounded. Recordings of border-ownership signals in visual cortex demonstrate how a stimulus is interpreted and reorganized in this case ( Qiu & von der Heydt, 2007 ). When the rounded squares were presented, the border-ownership signals at the edges pointed to the inner side of the squares, but when the straight squares were presented, the signals pointed to the inside of what was perceived as bars. The signals on the edges bounding the region of apparent overlap had now reversed. Hence, a slight modification of the conditions of good continuation leads to a spontaneous reorganization of shapes, which can also be observed in area V2 of the visual cortex (see Figure 24 , below).

The isolated square (a) and the squares with rounded corners (b) appear as distinct objects, but when the squares come in contact at the corners, two bars in transparent overlay are perceived (c). The small alteration of contours results in a perceptual re-organization. Note the reversal of border ownership at the marked edge. The population border ownership signal in the visual cortex (area V2) also shows this reversal (curves below). The dashed ellipses mark the receptive field positions.

Such reinterpretations do not seem to require a shift of attention but the role of attention in perceptual (re)organization is not a trivial matter. Gestalt psychologists have pointed out that attention is drawn to figures, whereas the background regions often go unnoticed. How unattended objects are processed is difficult to derive from phenomenal reports by participants who cannot avoid paying attention to the stimuli that they are supposed to judge. In contrast, neuronal recordings show the processing of all stimuli, whether attended or not. Neurophysiological studies investigating whether perceptual organization processes are preattentive, are influenced by attention, or take place only under attention have produced mixed results. In some situations, attention initiates a process of organization that reflects the intrinsic connectivity of the cortex. In other situations, organization emerges independently of attention, creating a structure for selective attention. For example, when monkeys were trained to mentally trace curves from the fixation point to a target, V1 neurons with receptive fields on the curves showed enhanced responses when the monkey traced the curve that passed through the receptive field, compared to when he traced the other curve ( Roelfsema, Lamme, & Spekreijse, 1998 ). The performance of the tracing task is thought to depend on collinear facilitation between neurons with neighboring receptive fields of similar orientation ( Gilbert, 1992 ), gated by attention ( Ito & Gilbert, 1999 ), resulting in a spread of enhancement from the fixation point along the curve ( Roelfsema, Scholte, & Spekreijse, 1999 ; Roelfsema, Lamme, & Spekreijse, 2000 ). More recent experiments have established similar effects for other grouping principles as well ( Wannig, Stanisor, & Roelfsema, 2011 ).

From these experiments it might seem that binding and grouping depend on attention, much as proposed by Treisman and Gelade (1980) , but with the difference that the structure develops according the connectivity in the cortex (specifically V1). However, studies on border-ownership selectivity show that there is also preattentive organization ( Qiu, Sugihara, & von der Heydt, 2007 ). For example, when monkeys performed a task that required selective attention to one of several figures in a display, it was found that the activity of most neurons was modulated independently by border-ownership and by attention. Moreover, the border-ownership signals in these neurons emerged simultaneously at attended and unattended figures. This shows that border-ownership signals are generated in parallel for the various objects in the display without the involvement of attention.

Although border-ownership signals can be generated without active allocation of attention, attention can also exert an influence on border assignment. This was demonstrated in an experiment by Qiu et al. (2007) , who presented two overlapping figures and measured the neuronal response to the border between the figures (the occluding contour), varying border-ownership and the side of attention. They found that attention could enhance or reduce the border-ownership signal produced by the overlap. When the occluding figure was attended, the population border-ownership signal for the occluding contour was enhanced, but when the occluded figure was attended, the signal was abolished (extrinsic edge suppression, cf. Nakayama et al., 1989 ). For the border between two abutting figures (where border-ownership is ambiguous), the signal would be determined by the side of attention. This corresponds to perception in Rubin’s ambiguous vase figure, where border-ownership can be flipped deliberately by changing attention from the vase region to a face region and vice versa (although spontaneous, automatic switches occur as well).

The interactions between attention and border-ownership may seem complicated, but there is an additional observation that suggests that the underlying mechanism is simple: The side of attentive enhancement and the preferred side of border-ownership of a neuron tend to be the same ( Qiu et al., 2007 ). This indicates that the same neural circuits that make a neuron border-ownership selective also produce the modulation by attention. One can explain all the above results by assuming that the edge signals produced by a figure are summed by a common “grouping cell” that, by feedback, sets the gain of the corresponding edge neurons ( Craft et al., 2007 ). Each border-ownership selective V2 neuron is connected to grouping cells on one side of its receptive field, and therefore shows enhanced responses when a figure is present on that side. The effects of attention are explained by assuming that volitional attention activates the grouping cells corresponding to the object to be attended ( Mihalas, Dong, von der Heydt, & Niebur, 2011 ). This raises the gain of the connected edge neurons. The one-sided connectivity of the edge neurons accounts for the asymmetric attention effect, and, because the same grouping cells produce border-ownership and attentive modulation, the side of attentive enhancement is also the preferred side of border-ownership.

6.5 Conclusion

In sum, the neurophysiological evidence from the last two decades seems to converge on the idea that the responses of cortical neurons depend on the properties of the overall configuration in the visual field as well as on the parameters of the stimulus in its receptive field. The connectivity and rules of the visual cortex allow illusory contours to be formed and figure-ground segmentation to be performed by autonomous processes that are at the same time also context-sensitive. The segregation of automatic and volitional processing closely resembles what the pioneers of Gestalt psychology envisioned, and many of the details currently discovered show parallels to the perceptual phenomena that they pointed out. As indicated by Westheimer (1999) , neurophysiology has come a long way since Hubel and Wiesel’s atomistic approach to orientation-selectivity of single cells in cat and monkey cortex, which were taken as prototypical feature detectors. The literature reviewed above matches well with the premature physiological theory postulated by Wertheimer (1922/1938 , p. 15): “The cells of an organism are parts of the whole and excitations occurring in them are thus to be viewed as part-processes functionally related to whole-processes of the entire organism.” Indeed, it gives a concrete meaning to it, by emphasizing the role of context-sensitive, autonomous processes within recurrent networks.

7 General Discussion and Conclusion

One century of research on perceptual grouping and figure-ground organization has yielded a wealth of knowledge regarding principles of perceptual organization, their ecological foundations, computational mechanisms, and neural underpinnings. In addition, it allows us to reflect upon the waxing and waning of views on the relationships between elementary sensations and integrated percepts. In this final section, we evaluate what Gestalt psychology has offered, how its limitations were overcome, how many of its main ideas still affect contemporary thinking about visual perception, and what the remaining challenges are for future research on perceptual organization.

7.1 The Swinging Pendulum of Gestalt History

Based on the discovery of phi or pure motion (i.e., perceived motion without objects being perceived as moving) exactly 100 years ago, Wertheimer (1912) and his fellow-pioneers of the Berlin school of Gestalt psychology arrived at some far-reaching conclusions causing a true revolution in psychology, philosophy, and neighboring disciplines (see also Table 3 again). Demonstrating a case where the phenomenological experience was clearly not composed of more elementary sensations, they concluded that structured wholes or Gestalten, rather than sensations, must be the primary units of mental life. They argued that the contents of awareness were not produced from associations or combinations between sensations. The whole is not only more than the sum of the parts, it is different because it has whole-properties that determine the part-properties as much as the other way around (i.e., two-sided dependency between wholes and parts). From the very beginning, these Gestalts were assumed to arise on the basis of continuous whole-processes in the brain, involving the “entire optical sector” from retina to cortex.

To substantiate these revolutionary ideas, phenomenological analysis of visual demonstrations was used to discover the laws of perceptual organization governing the experienced Gestalts ( Wertheimer, 1923 ). A plethora of interesting phenomena could be shown, but deriving “laws” from them proved to be harder: Even when the demonstrations were supplemented with parametric experiments, the stimuli were often very simple, and the ceteris paribus principles derived from them were easily destroyed by small extensions beyond the original constraints, yielding abundant exceptions to the rule. In somewhat richer stimuli, different factors determining the perceived organization interacted unpredictably, in line with the Gestalt spirit, but frustrating from the perspective of formulating laws.

To avoid a proliferation of “laws,” the law of Prägnanz was proposed as the fundamental law encompassing all the others but its formulation was left intentionally vague: “psychological organization will always be as ‘good’ as the prevailing conditions allow” ( Koffka, 1935 , p. 110) and “On the whole the reader should find no difficulty in seeing what is meant here. (…) [o]ne recognizes a resultant ‘good Gestalt’ simply by its own ‘inner necessity’” ( Wertheimer, 1923/1938 , p. 83). Inspiration was sought in physical phenomena that appeared to show similar global effects, in order to formulate field models of electric currents in the brain, which were supposed to be structurally and functionally isomorphic to the experienced Gestalts ( Köhler, 1920 ). But when Köhler’s electrical field theory lost its empirical basis due to Lashley’s and Sperry’s experiments, no alternatives were found to replace the physical but nonmechanistic foundations of Gestalt theory. With no testable quantitative models and no plausible neural underpinning, the Gestalt principles remained mere descriptions of interesting perceptual phenomena.

The discovery of single neurons being tuned to primitive stimulus attributes (e.g., line orientation, motion direction) in the 1950s led to a predominantly atomistic approach in neuroscience, and around the same time, computers models appeared to provide testable, mechanistic accounts of mental operations. Although the Gestalt line of work continued in relatively isolated corners of science (e.g., Metelli and Kanizsa in Italy, Michotte in Belgium, Oyama in Japan), the mainstream around that time was very much non-Gestaltist, if not anti-Gestaltist.

This started to change again when new Gestalt-like phenomena were discovered such as global precedence and configural superiority effects (e.g., Navon, 1977 ; Pomerantz et al., 1977 ). Perceptual organization became fashionable again (e.g., Beck, 1982 ; Kubovy & Pomerantz, 1981 ), partly because the Gestalt principles were thought to deliver suitable computational constraints on computer vision algorithms (e.g., Marr, 1982 ), and partly because neurophysiological studies revealed contextual modulation effects on cell responses from outside the cell’s classic receptive field (e.g., Allman et al., 1985 ) and clear neural correlates of Gestalt phenomena such as illusory contours (e.g., von der Heydt et al., 1984 ). As a result, the last two or three decades have seen a significant resurrection of fruitful empirical work on perceptual organization, to the extent that one could speak of a Gestalt revival, not only in the domain of visual perception (e.g., recent reviews on Gestalt principles in tactile perception by Gallace & Spence, 2011 , and in motor action by Klapp & Jagacinski, 2011 ).

7.2 Gestalt Research Anno 2012

Compared to the troublesome situation of Gestalt research in the mid-20 th century, contemporary vision science has made a lot of progress regarding perceptual grouping and figure-ground organization (see Table 4 , right column again). Phenomenological demonstrations with either very simple or confounded stimuli were supplemented with real experiments, using carefully constructed stimuli (e.g., dot lattices, Gabor displays) that allowed for parametric control, and sometimes also richer stimuli, in which cue combinations could take place. Isolated cues in well-controlled displays usually lead to weaker effects, whereas disparate weak cues often combine synergistically in more natural images. Exploiting the potential of modern techniques to create controlled but richer stimulus displays has also led to the discovery of new principles of grouping (e.g., generalized common fate, synchrony) and of figure-ground organization (e.g., extremal edges, articulating motion).

In addition to direct reports of perceptual experiences, indirect behavioral measures were developed, employing standard tools from experimental psychology (e.g., cueing, priming, matching) and psychophysics (e.g., response-bias free performance indices, thresholds). In most situations, these experiments enabled quantification of the strength of the factors influencing perceptual grouping and figure-ground organization, in some cases even formulated as real laws (e.g., Pure Distance law in grouping by proximity), or as clear demarcations between distinctive regimes (e.g., space-time coupling versus trade-off in apparent motion). In some areas of research, solid experimentation was accompanied by the development and testing of computational models, often starting from strong geometrical descriptions at the stimulus level or careful analysis of the natural image statistics, and then using the framework of statistical decision theory to characterize the regularities in the frequencies of responses. In other areas of research, psychophysical results could be related to neural mechanisms, at least in principle, by using similar stimuli and paradigms (e.g., illusory contours, figure-ground segmentation).

Hence, research on perceptual grouping and figure-ground organization has been able to build on the sophisticated research methods available in vision science in general, and this has also allowed for a somewhat less isolated treatment of these processes. Some progress has been made in linking these aspects of perceptual organization to other aspects of visual processing, to the extent that mid-level vision is often conceived as a relay-station between low-level vision with its rather hardwired extraction of primitive stimulus attributes (e.g., contrast, spatial frequency, orientation, motion direction) and high-level vision processes which interpret their meaning. In computer vision, grouping principles have been used to facilitate image processing, and image regularities have been used to facilitate the recovery of 3-D shapes from 2-D images. Biederman (1987) incorporated much of this progress in image understanding in his theory of human object recognition, thereby integrating Gestalt principles in mainstream cognitive science.

As a result of these decades of research on Gestalt issues with more modern techniques and in light of more current views, more moderate, sometimes even synthetic positions are now taken with respect to several of the traditional controversies (see Table 5 for an overview). In other words, although the negative attitude towards Gestalt psychology is gradually disappearing, modern vision science cannot be considered some kind of contemporary Gestalt approach either. First, much of what has been discovered goes against Gestalt psychology, as originally conceived. Rather than being primary, in the sense of preattentive and early, principles of grouping seem to operate at multiple levels, and although figure-ground segregation can occur preattentively, it can also be affected by attention. Whereas old-school Gestalt psychology emphasized that Gestalt laws are innate and intrinsic rather than learned from experience, recent studies with adult observers showed that past experience can exert an influence on several aspects of figure-ground perception. Moreover, although infants are already capable of grouping according to at least some grouping principles, developmental trends regarding other grouping principles indicate that visual experience does play a role as well. More generally, the convergence between psychophysical results and natural image statistics seems to indicate that the visual system is tuned to the properties of its environment. This seems to increase the validity of approaches emphasizing the importance of veridicality of perception and a general likelihood principle. In any case, within the Gestalt tradition, it raises the question of how internal laws based on a general minimum or simplicity principle might yield veridicality in the external world. (This issue is taken up again in the second paper; see Wagemans et al., 2012 ; Sections 5 and 6.)

Current more synthetic positions

Second, modern vision science appears to be incommensurate with “the fundamental ‘formula’ of Gestalt theory” ( Wertheimer, 1924/1938 , p. 2): “There are wholes, the behavior of which is not determined by that of their individual elements, but where the part-processes are themselves determined by the intrinsic nature of the whole.” Like the Gestaltists’ rivals in the early days, much of contemporary science is analytic rather than holistic. Even when configural effects are shown to occur time and time again, and even when strictly bottom-up models are replaced by more realistic models emphasizing feedforward-feedback loops and reentrant processing (e.g., Hochstein & Ahissar, 2002 ; Jehee et al., 2007 ; Lamme, 1995 ; Roelfsema, 2006 ; Roelfsema et al., 2002 ), this is still a far cry from recognizing the primary nature of structured wholes in experience, the importance of two-sided dependency between parts and wholes, and global field dynamics. In fact, Gestalt phenomena are still not very well integrated into mainstream thinking about the visual system’s operating principles (e.g., selectivity and tuning of single cells, V1 as a bank of filters or channels, segregated “what” and “where” streams, increasing receptive field size and invariance at higher levels of the hierarchy, specialized modules for separate object categories such as faces and places). Or, formulated more positively, establishing such an integration continues to provide serious challenges.

In sum, the current focus on Gestalt issues has not given rise to a new coherent school of thought, as it existed in the first few decades of Gestalt research. Current research on perceptual grouping and figure-ground organization is integrated well within mainstream vision science mainly regarding the research methods and techniques, not as much regarding its results, and certainly not regarding its deeper implications. It does not itself form an integrated domain of research, let alone a coherent research program or theoretical framework guided by a limited set of (meta)theoretical principles as their foundations, as was the case in the Berlin school of Gestalt psychology, started by Wertheimer (1912) a century ago. In addition to this major (meta)theoretical challenge, some other limitations of contemporary research on perceptual organization should be pointed out as well (for an overview, see Table 6 ).

Limitations and challenges to contemporary research on perceptual organization

7.3 Limitations and Challenges to Contemporary Research on Perceptual Organization

Perceptual grouping and figure-ground organization, although intimately connected, are not the same process. Perceptual grouping is concerned with the binding together of elements that are disjointed at the level of the proximal stimulus (retinal images). Often, but not always, grouping also entails its complement—leaving out some elements as noise or background elements, not selected for further processing. However, this does not mean that the group of selected and grouped elements gets figural status and that the non-selected, non-grouped elements become a background which continues behind the first group. This seems to require special conditions: “… phenomenal figures have boundary lines even when the corresponding objective figures have none. A good figure is always a ‘closed’ figure, which the boundary line has the function of closing” ( Koffka, 1922 , p. 14). Hence, it is clear that “groups” do not necessarily obey the same Gestalt properties as “figures,” and that grouping does not necessarily behave according to the same principles as figure-ground assignment. It would be interesting to focus more on the similarities and differences between the properties of “groups” and “figures,” and to characterize them better, for instance, on a graded continuum from weak to strong Gestalts, depending on the mutual relationships between the parts and the wholes or on how linear or nonlinear their underlying processes are. There is some overlap in the list of factors determining grouping and figure-ground assignment, but others apply to only one of the two forms of organization. There is a clear need for a systematic analysis of the common factors (and whether they are common because they affect the same component process, or because the same factor just happens to influence two independent processes in the same way), as well as of the organization-specific factors (and whether this specificity is due to a major functional difference or is merely a side effect of task demands).

In general, a thorough examination of the specific task requirements induced by the stimulus and imposed by the instructions is needed to be able to determine the processes involved and the potential generalization beyond the test conditions. For instance, in research aimed at the quantification of grouping by proximity, dot lattices are used and observers are asked to indicate in which orientation they see the linear arrangements of dots. Stimuli are highly regular, percepts are multistable (near equilibrium), and phenomenal reports are asked. Grouping involves all elements here, and the selection is at the level of percepts. When one orientation is seen, the others are still present in the stimulus. It is probably the noise in the visual system (i.e., internal noise) that causes switching from one percept to another. The situation is quite different in research aimed at the quantification of good continuation, in which random arrays of Gabor elements are mostly used, and observers are asked to detect or locate the target group (“snake”) embedded in a background of noise elements. Here, noise is present in the stimulus (i.e., external noise), and target elements must be selected for proper grouping. A participant’s response can be regarded as correct or incorrect, relative to the intended target group, although it is always possible that an observer truly sees a (spurious) group in the background elements, leading to a false alarm or mislocalization. How can we expect grouping principles to generalize between two such fundamentally different situations? Further progress with respect to theoretical integration will depend on experiments that bridge the gaps between different experimental paradigms, starting from analyses such as the above.

A similar recommendation applies to the connection between contour grouping, contour integration, contour completion, and the like. Stimulus and task differences complicate a theoretical synthesis. A major limitation of these studies is that they usually do not deal with “contours” in the sense of boundary lines with the function of closing an area or region. A “snake” in a Gabor array is a curvilinear group, it is not a contour, nor a boundary of a figure or an object (although the name itself refers to some object, accidentally). The literature on perceptual grouping in the context of interrupted or noisy contours in real images would be much more directly relevant to figure-ground organization if their snake stimuli were to be supplemented with curved groups that have more potential as boundaries of surfaces. Such research has been started (e.g., Machilsen et al., 2009 ; Machilsen & Wagemans, 2011 ; Nygård, Sassi, & Wagemans, 2011 ; Nygård, Van Looy, & Wagemans, 2009 ; Sassi, Vancleef, Machilsen, Panis, & Wagemans, 2010 ) but more is needed.

The same holds true in the other direction as well: Figure-ground organization could be related more strongly to perceptual grouping. Progress regarding figure-ground organization could profit from a more fine-grained analysis of the different components involved, from segregating regions (based on the relative similarity within a region/group and dissimilarity between different regions/groups), representing the contour with all of its relevant geometric properties (incl. grouping the contour fragments or linking the multiple borderline signals at different locations in the visual field), and relating these to relevant properties of the configuration within which the contour is embedded, to figure-ground assignment including the integration of multiple border-ownership signals and the overall border-ownership assignment. Moreover, such an interplay must be embedded into a dynamic system with cooperative and competitive units, with its own proper balance between deterministic and stochastic characteristics, to allow for perceptual switching to occur in cases of multistability. Again, crucial linking experiments are needed to facilitate such an integration of grouping and segregation processes into the figure-ground organization literature.

A fundamental limitation of current research on perceptual grouping as well as figure-ground organization is the shortage of computational process models. As mentioned earlier, most of the present models are statistical, descriptive models. In low-level vision, computational models exist that take stimulus images as input and produce binary task-related responses as output (e.g., Yes/No in a detection task), spelling out all of the intermediate processing steps by equations with a limited set of free parameters. Such models can be fitted directly to psychophysical results obtained with human observers, usually yielding increased insight in the underlying mechanisms, or at least providing some constraints on fundamental principles that allow further progress to be made by refinement of the models or additional psychophysical testing. Although psychophysical methods have been used to directly compare thresholds for detecting deviations from uniformity and thresholds for grouping based on the same nonuniformities ( Gori & Spillmann, 2010 ), full-fledged computational models with integrated psychophysics are rare in mid-level vision (e.g., Geisler & Super, 2000 ). One advantage that low-level vision has compared to mid-level vision is that it can build more directly on a strong and solid psychophysical tradition, in which stimuli, tasks, data analysis techniques, and computational models are more strongly integrated with one another, reflecting a more mature status of science. Significant steps forward could be taken if this quantitative computational tradition would be pushed forward from low- to mid-level vision.

Low-level vision can also relate more directly to neurophysiological findings than mid-level vision. Although we believe in the value of a thorough phenomenological analysis of interesting perceptual phenomena (e.g., Sinico, 2008 ), we are also convinced that explanations at a neural level provide considerable added value (e.g., Spillmann, 2009 ). Single-cell responses of V1 are very well characterized in relation to well-controlled low-level stimulus characteristics, and their response properties and tuning are relatively well-understood (for review, see Carandini et al., 2005 ). Where context effects or more realistic configurations are concerned, the combinatorial space of stimulus attributes becomes prohibitive for similar parametric studies (but see Brincat & Connor, 2004 , 2006 , for a most interesting attempt). And, when true Gestalt experiences are at stake, either fundamental limitations of the research methods (fMRI or EEG) or problems with cross-species comparisons (from monkey to human) are unavoidable. As a result, success stories regarding direct neural correlates of interesting Gestalt phenomena are relatively rare. Similar progress regarding neurocomputational models, which are supposed to rely on solid computational principles that are compatible with known neurophysiology and human psychophysics, requires painstaking bridging efforts and also raises many open questions with respect to specific details that can be addressed only by multidisciplinary teams (e.g., psychophysicists, modelers, neurophysiologists, neuroanatomists).

Perceptual grouping and figure-ground organization are two important aspects of perceptual organization, but they are not the only ones. Also interesting are, for instance, the representation of part-whole relationships in a hierarchical structure, texture segregation, geometric distortions due to context or field effects, embedded figures, and holistic processing of faces. Many of the above lessons we derived from this review also apply to these other areas of mid-level vision.

7.4 Conclusion

We hope this review has demonstrated that rumors about the death of Gestalt psychology were greatly exaggerated ( Epstein, 1988 ). On the contrary, the field of research on perceptual grouping and figure-ground organization is thriving, and progress has been tremendous compared to the situation of 100 years ago. However, significant challenges remain. The above discussion has outlined an open-ended research program, like Wertheimer and his fellow-pioneers did. However, we are now able to build on a research tradition of more than a century. We are convinced that we can reconsider some of the old puzzles at a much more advanced scientific level now. The most important challenge will be to integrate better this research tradition with the rest of vision science. Such an integration will strongly depend on progress regarding the conceptual and theoretical foundations of the Gestalt approach. This will be the focus of the second of this twin set of review papers on the occasion of the centennial anniversary of Gestalt psychology ( Wagemans et al., 2012 ).

Acknowledgements

Johan Wagemans was supported by the Methusalem program from the Flemish Government (METH/08/02) for a research program aimed at the integration of Gestalt psychology into modern vision science (see www.gestaltrevision.be ), and by fellowships from the Research Fund (FWO-Flanders) and from IEA-Paris during his sabbatical. James H. Elder was supported by NSERC, OCE and GEOIDE. Michael Kubovy was supported by NSF grant BCS 1027120 and 1027259. Stephen E. Palmer was supported by NSF BCS 1059088 and 0745820. Mary A. Peterson was supported by NSF (BCS0960529). Manish Singh was supported by NIH EY021494 (joint with Jacob Feldman) and NSF DGE 0549115 (Rutgers IGERT in Perceptual Science). Rüdiger von der Heydt was supported by National Institutes of Health Grants EY02966 and EY16281 and by Office of Naval Research Grant N000141010278. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the funding agencies.

We would like to thank Stephanie Poot for administrative help with the reference list, the copyrights, and the layout, as well as M. Dorothee Augustin, Wouter Braet, Peter Claessens, Maarten Demeyer, Lee de-Wit, Sergei Gepshtein, Frouke Hermens, Ruth Kimchi, Ervin Poljac, Peter Van der Helm, Cees van Leeuwen, and the reviewers for comments on previous drafts.

• Alais D, Blake R, Lee SH. Visual features that vary together over time group together over space. Nature Neuroscience. 1998; 1 :160–164. [ PubMed ] [ Google Scholar ]
• Alexander DM, van Leeuwen C. Mapping of contextual modulation in the population response of primary visual cortex. Cognitive Neurodynamics. 2010; 4 :1–24. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Allman J, Miezin F, McGuinness E. Stimulus-specific responses from beyond the classical receptive field: Neurophysiological mechanisms for local-global comparisons in visual neurons. Annual Review of Neuroscience. 1985; 8 :407–430. [ PubMed ] [ Google Scholar ]
• Altmann CF, Bülthoff HH, Kourtzi Z. Perceptual organization of local elements into global shapes in the human visual cortex. Current Biology. 2003; 13 :342–349. [ PubMed ] [ Google Scholar ]
• Anderson BL. The demise of the identity hypothesis and the insufficiency and nonnecessity of contour relatability in predicting object interpolation: Comment on Kellman, Garrigan, and Shipley (2005) Psychological Review. 2007; 114 :470–487. [ PubMed ] [ Google Scholar ]
• Anderson BL, Singh M, Fleming RW. The interpolation of object and surface structure. Cognitive Psychology. 2002; 44 :148–190. [ PubMed ] [ Google Scholar ]
• Angelucci A, Levitt JB, Walton EJS, Hupé JM, Bullier J, Lund JS. Circuits for local and global signal integration in primary visual cortex. Journal of Neuroscience. 2002; 22 :8633–8646. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Arnheim R. Art and visual perception. Berkeley, CA: University of California Press; 1967. [ Google Scholar ]
• Ash MG. Gestalt psychology in German culture, 1890–1967: Holism and the quest for objectivity. Cambridge, MA: Cambridge University Press; 1995. [ PubMed ] [ Google Scholar ]
• Attneave F. Some informational aspects of visual perception. Psychological Review. 1954; 61 :183–193. [ PubMed ] [ Google Scholar ]
• Attneave F. Multistability in perception. Scientific American. 1971; 225 :62–71. [ PubMed ] [ Google Scholar ]
• Attneave F, Arnoult MD. The quantitative study of shape and pattern perception. Psychological Bulletin. 1956; 53 :452–471. [ PubMed ] [ Google Scholar ]
• Bahnsen P. Eine Untersuchung über Symmetrie und Asymmetrie bei visuellen Wahrnehmungen. Zeitschrift für Psychologie. 1928; 108 :129–154. [ Google Scholar ]
• Bakin JS, Nakayama K, Gilbert CD. Visual responses in monkey areas V1 and V2 to threedimensional surface configurations. Journal of Neuroscience. 2000; 20 :8188–8198. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Barenholtz E. Convexities move because they contain matter. Journal of Vision. 2010; 10 (11):19, 1–12. [ PubMed ] [ Google Scholar ]
• Barenholtz E, Feldman J. Determination of visual figure and ground in dynamically deforming shapes. Cognition. 2006; 101 :530–544. [ PubMed ] [ Google Scholar ]
• Barenholtz E, Tarr MJ. Figure–ground assignment to a translating contour: A preference for advancing vs. receding motion. Journal of Vision. 2009; 9 (5):27, 1–9. [ PubMed ] [ Google Scholar ]
• Baylis GC, Driver J. Parallel computation of symmetry but not repetition within visual shapes. Visual Cognition. 1994; 1 :377–400. [ Google Scholar ]
• Baylis GC, Driver J. Obligatory edge assignment in vision: The role of figure and part segmentation in symmetry detection. Journal of Experimental Psychology: Human Perception and Performance. 1995; 21 :1323–1342. [ Google Scholar ]
• Beck DM, Palmer SE. Top-down influences on perceptual grouping. Journal of Experimental Psychology: Human Perception and Performance. 2002; 28 :1071–1084. [ PubMed ] [ Google Scholar ]
• Beck J, editor. Organization and representation in vision. Hillsdale, NJ: Erlbaum; 1982. [ Google Scholar ]
• Bertamini M. Who owns the contour of a visual hole? Perception. 2006; 35 :883–894. [ PubMed ] [ Google Scholar ]
• Bertamini M, Hulleman J. Amodal completion and visual holes (static and moving) Acta Psychologica. 2006; 123 :55–72. [ PubMed ] [ Google Scholar ]
• Bhatt RS, Quinn PC. How does learning impact development in infancy? The case of perceptual organization. Infancy. 2011; 16 :2–38. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Biederman I. Recognition-by-components: A theory of human image understanding. Psychological Review. 1987; 94 :115–147. [ PubMed ] [ Google Scholar ]
• Binford T. Inferring surfaces from images. Artificial Intelligence. 1981; 17 :205–244. [ Google Scholar ]
• Blum H. Biological shape and visual science (Part I) Journal of Theoretical Biology. 1973; 38 :205–287. [ PubMed ] [ Google Scholar ]
• Bravais A. Etudes cristallographiques: Mémoire sur les systèmes formés par des points distribués régulièrement sur un plan ou dans l’espace. Journal de l’´Ecole polytechnique, Cahier. 1850; 33 ((tome XIX)):1–128. (Translation reprinted as (1949) “Memoir No. 1 Crystallographic studies: On the systems formed by points regularly distributed on a plane or in space” (A. J. Shaler, Trans.). New York, NY: Crystallographic Society of America). [ Google Scholar ]
• Bregman AS. Asking the"what for” question in auditory perception. In: Kubovy M, Pomerantz JR, editors. Perceptual organization. Hillsdale, NJ: Erlbaum; 1981. pp. 99–118. [ Google Scholar ]
• Bregman AS. Auditory scene analysis : The perceptual organization of sound. Cambridge, MA: Bradford/MIT Press; 1990. [ Google Scholar ]
• Brincat SL, Connor CE. Underlying principles of visual shape selectivity in posterior inferotemporal cortex. Nature Neuroscience. 2004; 7 :880–886. [ PubMed ] [ Google Scholar ]
• Brincat SL, Connor CE. Dynamic shape synthesis in posterior inferotemporal cortex. Neuron. 2006; 49 :17–24. [ PubMed ] [ Google Scholar ]
• Brown JF, Voth AC. The path of seen movement as a function of the vector-field. American Journal of Psychology. 1937; 49 :543–563. [ Google Scholar ]
• Burge J, Fowlkes C, Banks MS. Natural-scene statistics predict how the figure–ground cue of convexity affects human depth perception. Journal of Neuroscience. 2010; 30 :7269–7280. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Burge J, Peterson MA, Palmer SE. Ordinal configural cues combine with metric disparity in depth perception. Journal of Vision. 2005; 5 (6):5, 534–542. [ PubMed ] [ Google Scholar ]
• Burt P, Sperling G. Time, distance, and feature trade-offs in visual apparent motion. Psychological Review. 1981; 88 :171–195. [ PubMed ] [ Google Scholar ]
• Canny JF. Finding edges and lines in images. Cambridge, MA: MIT Artificial Intelligence Laboratory; 1983. (Unpublished Master Thesis) [ Google Scholar ]
• Carandini M, Demb JB, Mante V, Tolhurst DJ, Dan Y, Olshausen BA, Gallant JL, Rust NC. Do we know what the early visual system does? Journal of Neuroscience. 2005; 25 :10577–10597. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Casco C. The relationship between visual persistence and event perception in bistable motion display. Perception. 1990; 19 :437–445. [ PubMed ] [ Google Scholar ]
• Cavanaugh JR, Bair W, Movshon JA. Nature and interaction of signals from the receptive field center and surround in macaque V1 neurons. Journal of Neurophysiology. 2002; 88 :2530–2546. [ PubMed ] [ Google Scholar ]
• Claessens PME, Wagemans J. Perceptual grouping in Gabor lattices: Proximity and alignment. Perception & Psychophysics. 2005; 67 :1446–1459. [ PubMed ] [ Google Scholar ]
• Claessens PME, Wagemans J. A Bayesian framework for cue integration in multistable grouping: Proximity, collinearity, and orientation priors in zigzag lattices. Journal of Vision. 2008; 8 (7):33, 1–23. [ PubMed ] [ Google Scholar ]
• Cohen EH, Singh M. Geometric determinants of shape segmentation: Tests using segment identification. Vision Research. 2007; 47 :2825–2840. [ PubMed ] [ Google Scholar ]
• Coren S. Subjective contours and apparent depth. Psychological Review. 1972; 79 :359–367. [ PubMed ] [ Google Scholar ]
• Craft E, Schütze H, Niebur E, von der Heydt R. A neural model of figure-ground organization. Journal of Neurophysiology. 2007; 97 :4310–4326. [ PubMed ] [ Google Scholar ]
• Dawson M, Nevin-Meadows N, Wright R. Polarity matching in the Ternus configuration. Vision Research. 1994; 34 :3347–3359. [ PubMed ] [ Google Scholar ]
• De Winter J, Wagemans J. Segmentation of object outlines into parts: A large-scale integrative study. Cognition. 2006; 99 :275–325. [ PubMed ] [ Google Scholar ]
• Driver J, Baylis GC. Edge-assignment and figure-ground segmentation in short-term visual masking. Cognitive Psychology. 1996; 31 :248–306. [ PubMed ] [ Google Scholar ]
• Driver J, Baylis GC, Rafal RD. Preserved figure-ground segregation and symmetry perception in visual neglect. Nature. 1992; 360 :73–75. [ PubMed ] [ Google Scholar ]
• Duncan RO, Albright TD, Stoner GR. Occlusion and the interpretation of visual motion: Perceptual and neuronal effects of context. Journal of Neuroscience. 2000; 20 :5885–5897. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Duncker K. Über induzierte Bewegung (Ein Beitrag zur Theorie optisch wahrgenommener Bewegung) [Concerning induced movement (Contribution to the theory of visually perceived movement)] Psychologische Forschung. 1929; 12 :180–259. [ Google Scholar ]
• Elder JH, Goldberg RM. Ecological statistics of Gestalt laws for the perceptual organization of contours. Journal of Vision. 2002; 2 (4):5, 324–353. [ PubMed ] [ Google Scholar ]
• Elder JH, Krupnik A, Johnston LA. Contour grouping with prior models. IEEE Transactions on Pattern Analysis and Machine Intelligence. 2003; 25 :661–674. [ Google Scholar ]
• Elder JH, Zucker SW. The effect of contour closure on the rapid discrimination of two-dimensional shapes. Vision Research. 1993; 33 :981–991. [ PubMed ] [ Google Scholar ]
• Elder JH, Zucker SW. A measure of closure. Vision Research. 1994; 34 :3361–3369. [ PubMed ] [ Google Scholar ]
• Ellis WD, editor. A source book of Gestalt psychology. London, U. K.: Routledge & Kegan Paul Ltd; 1938. [ Google Scholar ]
• Epstein W. Has the time come to rehabilitate Gestalt theory? Psychological Research. 1988; 50 :2–6. [ PubMed ] [ Google Scholar ]
• Epstein W, DeShazo D. Recency as a function of perceptual oscillation. American Journal of Psychology. 1961; 74 :215–223. [ PubMed ] [ Google Scholar ]
• Estrada FJ, Elder JH. Multi-scale contour extraction based on natural image statistics. In: Schmid C, Soatto S, Tomasi C, editors. Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition (CVPR06, p. 183) New York, NY: IEEE Computer Society; 2006. [ Google Scholar ]
• Fantoni C, Bertamini M, Gerbino W. Contour curvature polarity and surface interpolation. Vision Research. 2005; 45 :1047–1062. [ PubMed ] [ Google Scholar ]
• Fantoni C, Gerbino W. Contour interpolation by vector-field combination. Journal of Vision. 2003; 3 (4):4, 281–303. [ PubMed ] [ Google Scholar ]
• Farid H. Temporal synchrony in perceptual grouping: A critique. Trends in Cognitive Science. 2002; 6 :284–288. [ PubMed ] [ Google Scholar ]
• Farid H, Adelson EH. Synchrony does not promote grouping in temporally structured displays. Nature Neuroscience. 2001; 4 :875–876. [ PubMed ] [ Google Scholar ]
• Feldman J. Formation of visual “objects” in the early computation of spatial relations. Perception & Psychophysics. 2007; 69 :816–827. [ PubMed ] [ Google Scholar ]
• Feldman J, Singh M. Bayesian estimation of the shape skeleton. Proceedings of the National Academy of Sciences of the U.S.A. 2006; 103 :18014–18019. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Field DJ, Hayes A, Hess RF. Contour integration by the human visual system: Evidence for a local "association field” Vision Research. 1993; 33 :173–193. [ PubMed ] [ Google Scholar ]
• Field DJ, Hayes A, Hess RF. The roles of polarity and symmetry in the perceptual grouping of contour fragments. Spatial Vision. 2000; 13 :51–66. [ PubMed ] [ Google Scholar ]
• Finkel LH, Sajda P. Object discrimination based on depth-from-occlusion. Neural Computation. 1992; 4 :901–921. [ Google Scholar ]
• Froyen V, Feldman J, Singh M. A Bayesian framework for figure-ground interpretation. In: Lafferty J, Williams CKI, Shawe-Taylor J, Zemel RS, Culotta A, editors. Advances in Neural Information Processing Systems. Vol. 23. Vancouver, B.C., Canada: Curran Associates, Inc; 2010. pp. 631–639. [ Google Scholar ]
• Fulvio JM, Singh M. Surface geometry influences the shape of illusory contours. Acta Psychologica. 2006; 123 :20–40. [ PubMed ] [ Google Scholar ]
• Fulvio JM, Singh M, Maloney LT. Precision and consistency of contour interpolation. Vision Research. 2008; 48 :831–849. [ PubMed ] [ Google Scholar ]
• Gallace A, Spence C. To what extent do Gestalt grouping principles influence tactile perception? Psychological Bulletin. 2011; 137 :538–561. [ PubMed ] [ Google Scholar ]
• Geisler WS, Perry JS. Contour statistics in natural images: Grouping across occlusions. Visual Neuroscience. 2009; 26 :109–121. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Geisler WS, Perry JS, Super BJ, Gallogly DP. Edge co-occurence in natural images predicts contour grouping performance. Vision Research. 2001; 41 :711–724. [ PubMed ] [ Google Scholar ]
• Geisler WS, Super BJ. Perceptual organization of two-dimensional patterns. Psychological Review. 2000; 107 :677–708. [ PubMed ] [ Google Scholar ]
• Gepshtein S, Kubovy M. The emergence of visual objects in space-time. Proceedings of the National Academy of Sciences of the U.S.A. 2000; 97 :8186–8191. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Gepshtein S, Kubovy M. The lawful perception of apparent motion. Journal of Vision. 2007; 7 (8):9, 1–15. [ PubMed ] [ Google Scholar ]
• Gerhardstein P, Kovács I, Ditre J, Feher A. Detection of contour continuity and closure in threemonth- olds. Vision Research. 2004; 44 :2982–2988. [ PubMed ] [ Google Scholar ]
• Ghose T, Palmer SE. Extremal edges versus other principles of figure-ground organization. Journal of Vision. 2010; 10 (8):3, 1–17. [ PubMed ] [ Google Scholar ]
• Gibson BS, Peterson MA. Does orientation-independent object recognition precede orientationdependent recognition? Evidence from a cuing paradigm. Journal of Experimental Psychology: Human Perception and Performance. 1994; 20 :299–316. [ PubMed ] [ Google Scholar ]
• Gibson JJ. The legacies of Koffka’s principles. Journal of the History of Behavioral Sciences. 1971; 7 :3–9. [ PubMed ] [ Google Scholar ]
• Gilbert CD. Horizontal integration and cortical dynamics. Neuron. 1992; 9 :1–13. [ PubMed ] [ Google Scholar ]
• Gilchrist ID, Humphreys GW, Riddoch MJ, Neumann H. Luminance and edge information in grouping: A study using visual search. Journal of Experimental Psychology: Human Perception and Performance. 1997; 23 :464–480. [ PubMed ] [ Google Scholar ]
• Gillam BJ, Grove PM. Contour entropy: A new determinant of perceiving ground or a hole. Journal of Experimental Psychology: Human Perception and Performance. 2011; 37 :750–757. [ PubMed ] [ Google Scholar ]
• Gillam BJ, Nakayama K. Subjective contours at line terminations depend on scene layout analysis, not image processing. Journal of Experimental Psychology: Human Perception and Performance. 2002; 28 :43–53. [ Google Scholar ]
• Goldreich D, Peterson MA. A Bayesian observer replicates convexity context effects in figureground perception. Seeing & Perceiving. 2012; 25 :365–395. [ PubMed ] [ Google Scholar ]
• Gori S, Spillmann L. Detection vs. grouping thresholds for elements differing in spacing, size and luminance. An alternative approach towards the psychophysics of Gestalten. Vision Research. 2010; 50 :1194–1202. [ PubMed ] [ Google Scholar ]
• Gottschaldt K. Über den Einfluβ der Erfahrung auf die Wahrnehmung von Figuren. I. Über den Einfluβ gehäufter Einprägung von Figuren auf ihre Sichtbarkeit in umfassenden Konfigurationen [About the influence of experience on the perception of figures] Psychologische Forschung. 1926; 8 :261–317. [ Google Scholar ]
• Gray CM, Singer W. Stimulus-specific neuronal oscillations in orientation columns of cat visual cortex. Proceedings of the National Academy of Sciences of the U.S.A. 1989; 86 :1698–1702. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Gregory RL. Cognitive contours. Nature. 1972; 238 :51–52. [ PubMed ] [ Google Scholar ]
• Gregory RL. Illusory contours and occluding surfaces. In: Petry S, Meyer GE, editors. Perception of illusory contours. New York, NY: Springer; 1987. pp. 81–89. [ Google Scholar ]
• Gregory RL, Harris J. Illusory contours and stereo depth. Perception, & Psychophysics. 1974; 15 :411–416. [ Google Scholar ]
• Grossberg S. 3-D vision and figure-ground separation by visual cortex. Perception, & Psychophysics. 1994; 55 :48–121. [ PubMed ] [ Google Scholar ]
• Grossberg S, Mingolla E. Neural dynamics of form perception: Boundary completion, illusory figures, and neon color spreading. Psychological Review. 1985; 92 :173–211. [ PubMed ] [ Google Scholar ]
• Grünbaum B, Shephard GC. Tilings and patterns: An introduction. New York, NY: W. H. Freeman and Company; 1987. [ Google Scholar ]
• Guttman SE, Kellman PJ. Contour interpolation revealed by a dot localization paradigm. Vision Research. 2004; 44 :1799–1815. [ PubMed ] [ Google Scholar ]
• Hadad BS, Kimchi R. Developmental trends in utilizing perceptual closure for grouping of shape: Effects of spatial proximity and collinearity. Perception & Psychophysics. 2006; 68 :1264–1273. [ PubMed ] [ Google Scholar ]
• Hadad BS, Maurer D, Lewis TL. The development of contour interpolation: Evidence from subjective contours. Journal of Experimental Child Psychology. 2010a; 106 :163–176. [ PubMed ] [ Google Scholar ]
• Hadad BS, Maurer D, Lewis TL. The effects of spatial proximity and collinearity on contour integration in adults and children. Vision Research. 2010b; 50 :772–778. [ PubMed ] [ Google Scholar ]
• Harrower MR. Some factors determining figure-ground articulation. British Journal of Psychology. 1936; 26 :407–424. [ Google Scholar ]
• Hartmann GW. Gestalt psychology: A survey of facts and principles. New York, NY: Ronald Press; 1935. [ Google Scholar ]
• Hatfield G, Epstein W. The status of the minimum principle in the theoretical analysis of visual perception. Psychological Bulletin. 1985; 97 :155–186. [ PubMed ] [ Google Scholar ]
• He Z, Ooi T. Perceptual organization of apparent motion in the Ternus display. Perception. 1999; 28 :877–892. [ PubMed ] [ Google Scholar ]
• Heitger F, Rosenthaler L, von der Heydt R, Peterhans E, Kübler O. Simulation of neural contour mechanisms: From simple to end-stopped cells. Vision Research. 1992; 32 :963–981. [ PubMed ] [ Google Scholar ]
• Heitger F, von der Heydt R, Peterhans E, Rosenthaler L, Kübler O. Simulation of neural contour mechanisms: Representing anomalous contours. Image and Vision Computing. 1998; 16 :407–421. [ Google Scholar ]
• Helson H. The fundamental propositions of Gestalt psychology. Psychological Review. 1933; 40 :13–32. [ Google Scholar ]
• Hochberg JE, Hardy D. Brightness and proximity factors in grouping. Perceptual and Motor Skills. 1960; 10 :22. [ Google Scholar ]
• Hochberg JE, McAlister E. A quantitative approach to figural "goodness". Journal of Experimental Psychology. 1953; 46 :361–364. [ PubMed ] [ Google Scholar ]
• Hochberg JE, Silverstein A. A quantitative index of stimulus-similarity: Proximity versus differences in brightness. American Journal of Psychology. 1956; 69 :456–458. [ PubMed ] [ Google Scholar ]
• Hochstein S, Ahissar M. View from the top: hierarchies and reverse hierarchies in the visual system. Neuron. 2002; 36 :791–804. [ PubMed ] [ Google Scholar ]
• Hoffman DD, Richards WA. Parts of recognition. Cognition. 1984; 18 :65–96. [ PubMed ] [ Google Scholar ]
• Hoffman DD, Singh M. Salience of visual parts. Cognition. 1997; 63 :29–78. [ PubMed ] [ Google Scholar ]
• Hopfield JJ. Neural networks and physical systems with emergent collective computational abilities. Proceedings of the National Academy of Sciences of the U.S.A. 1982; 79 :2554–2558. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Hsiao HH. A suggestive review of Gestalt theory. Psychological Review. 1928; 35 :280–297. [ Google Scholar ]
• Hubel DH, Wiesel TN. Receptive fields and functional architecture of monkey striate cortex. Journal of Physiology. 1968; 195 :215–243. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Huggins PS, Zucker SW. Proceedings of the 8th IEEE International Conference on Computer Vision. Vol. 2. Los Alamitos, CA: IEEE Computer Society; 2001. Folds and cuts: How shading flows into edges; pp. 153–158. [ Google Scholar ]
• Hulleman J, Humphreys GW. Is there an assignment of top and bottom during symmetry perception? Perception. 2004; 33 :615–620. [ PubMed ] [ Google Scholar ]
• Humphreys GW, Riddoch MJ. Interactions between object and space systems revealed through neuropsychology. In: Meyer DE, Kornblum S, editors. Attention and Performance. Vol. 24. Cambridge, MA: MIT Press; 1993. pp. 183–218. [ Google Scholar ]
• Ito M, Gilbert CD. Attention modulates contextual influences in the primary visual cortex of alert monkeys. Neuron. 1999; 22 :593–604. [ PubMed ] [ Google Scholar ]
• Jacobs DW. Robust and efficient detection of salient convex groups. IEEE Transactions on Pattern Analysis and Machine Intelligence. 1996; 18 :23–37. [ Google Scholar ]
• Jacobs DW. What makes viewpoint-invariant properties perceptually salient? Journal of the Optical Society of America A. 2003; 20 :1304–1320. [ PubMed ] [ Google Scholar ]
• Jehee JFM, Lamme VAF, Roelfsema PR. Boundary assignment in a recurrent network architecture. Vision Research. 2007; 47 :1153–1165. [ PubMed ] [ Google Scholar ]
• Kanizsa G. Alcune osservazioni sull’ effetto Musatti. Archivio di Psicologia Neurologia e Psichiatria. 1954; 15 :265–271. (Translation reprinted as “Some observations on color assimilation”. In G. Kanizsa, (1979). Organization in vision: Essays on Gestalt perception (pp. 143–150). New York, NY: Praeger Publishers.) [ PubMed ] [ Google Scholar ]
• Kanizsa G. Condizioni ed effetti della trasparenza fenomenica. Rivista di Psicologia. 1955a; 49 :3–18. (Translation reprinted as “Phenomenal transparency”. In G. Kanizsa, (1979). Organization in vision: Essays on Gestalt perception (pp. 151–169). New York, NY: Praeger Publishers.) [ Google Scholar ]
• Kanizsa G. Margini quasi-percettivi in campi con stimolazione omogenea [Quasi-perceptual margins in homogeneously stimulated fields] Rivista di Psicologia. 1955b; 49 :7–30. [ Google Scholar ]
• Kanizsa G. Subjective contours. Scientific American. 1976; 234 :48–52. [ PubMed ] [ Google Scholar ]
• Kanizsa G. Organization in vision: Essays on Gestalt psychology. New York, NY: Praeger; 1979. [ Google Scholar ]
• Kanizsa G, Gerbino W. Convexity and symmetry in figure-ground organization. In: Henle M, editor. Art and artefacts. New York, NY: Springer; 1976. pp. 25–32. [ Google Scholar ]
• Kellman PJ, Garrigan P, Shipley TF, Keane BP. Interpolation processes in object perception: Reply to Anderson (2007) Psychological Review. 2007; 114 :488–502. [ PubMed ] [ Google Scholar ]
• Kellman PJ, Shipley TF. A theory of visual interpolation in object perception. Cognitive Psychology. 1991; 23 :141–221. [ PubMed ] [ Google Scholar ]
• Kienker PK, Sejnowski TJ, Hinton GE, Schumacher LE. Separating figure from ground with a parallel network. Perception. 1986; 15 :197–216. [ PubMed ] [ Google Scholar ]
• Kimchi R. The perceptual organization of visual objects: A microgenetic analysis. Vision Research. 2000; 40 :1333–1347. [ PubMed ] [ Google Scholar ]
• Kimchi R, Behrman M, Olson CR, editors. Perceptual organization in vision. Behavioral and neural perspectives. Mahwah, NJ: Erlbaum; 2003. [ Google Scholar ]
• Kimchi R, Hadad BS. Influence of past experience on perceptual grouping. Psychological Science. 2002; 13 :41–47. [ PubMed ] [ Google Scholar ]
• Kimchi R, Hadad B, Behrmann M, Palmer SE. Microgenesis and ontogenesis of perceptual organization: Evidence from global and local processing of hierarchical patterns. Psychological Science. 2005; 16 :282–290. [ PubMed ] [ Google Scholar ]
• Kimchi R, Peterson MA. Figure-ground segmentation can occur without attention. Psychological Science. 2008; 19 :660–668. [ PubMed ] [ Google Scholar ]
• King DB, Wertheimer M [Michael] Max Wertheimer & Gestalt theory. New Brunswick, NJ: Transaction Publishers; 2005. [ Google Scholar ]
• Klapp ST, Jagacinski RJ. Gestalt principles in the control of motor action. Psychological Bulletin. 2011; 137 :443–462. [ PubMed ] [ Google Scholar ]
• Koffka K. Perception: An introduction to the “Gestalt-Theorie” Psychological Bulletin. 1922; 19 :531–585. [ Google Scholar ]
• Koffka K. Principles of Gestalt psychology. London, U.K.: Lund Humphries; 1935. [ Google Scholar ]
• Kogo N, Strecha C, Van Gool L, Wagemans J. Surface construction by a 2-D differentiationintegration process: A neurocomputational model for perceived border-ownership, depth, and lightness in Kanizsa figures. Psychological Review. 2010; 117 :406–439. [ PubMed ] [ Google Scholar ]
• Köhler W. Die physischen Gestalten in Ruhe und im stationären Zustand. Eine natur-philosophische Untersuchung. Braunschweig. Germany: Friedr. Vieweg und Sohn; 1920. (Translated extract reprinted as “Physical Gestalten”. In W. D. Ellis (Ed.), (1938). A source book of Gestalt psychology (pp. 17–54). (London, U. K.: Routledge & Kegan Paul Ltd.) [ Google Scholar ]
• Köhler W. Dynamics in psychology. New York, NY: Liveright; 1940. [ Google Scholar ]
• Köhler W. Unsolved problems in the field of figural after-effects. Psychological Record. 1965; 15 :63–83. [ Google Scholar ]
• Köhler W, Held R. The cortical correlate of pattern vision. Science. 1949; 110 :414–419. [ PubMed ] [ Google Scholar ]
• Köhler W, Wallach H. Figural after-effects: An investigation of visual processes. Proceedings of the American Philosophical Society. 1944; 88 :269–357. [ Google Scholar ]
• Korte A. Kinematoskopische Untersuchungen [Kinematoscopic investigations] Zeitschrift für Psychologie. 1915; 72 :194–296. [ Google Scholar ]
• Kourtzi Z, Tolias AS, Altmann CF, Augath M, Logothetis NK. Integration of local features into global shapes: Monkey and human fMRI studies. Neuron. 2003; 37 :333–346. [ PubMed ] [ Google Scholar ]
• Kovács I. Human development of perceptual organization. Vision Research. 2000; 40 :1301–1310. [ PubMed ] [ Google Scholar ]
• Kovács I, Julesz B. A closed curve is much more than an incomplete one: Effect of closure in figureground segmentation. Proceedings of the National Academy of Sciences of the U.S.A. 1993; 90 :7495–7497. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Kramer P, Yantis S. Perceptual grouping in space and time: Evidence from the Ternus display. Perception & Psychophysics. 1997; 59 :87–99. [ PubMed ] [ Google Scholar ]
• Krantz DH, Luce RD, Suppes P, Tversky A. Foundations of measurement (Vol. I: Additive and polynomial representations. New York, NY: Academic Press; 1971. [ Google Scholar ]
• Kruger N. Collinearity and parallelism are statistically significant second order relations of complex cell responses. Neural Processing Letters. 1998; 8 :117–129. [ Google Scholar ]
• Kubovy M. The perceptual organization of dot lattices. Psychonomic Bulletin & Review. 1994; 1 :182–190. [ PubMed ] [ Google Scholar ]
• Kubovy M, Holcombe AO, Wagemans J. On the lawfulness of grouping by proximity. Cognitive Psychology. 1998; 35 :71–98. [ PubMed ] [ Google Scholar ]
• Kubovy M, Pomerantz JR. Perceptual organization. Hillsdale, NJ: Erlbaum; 1981. [ Google Scholar ]
• Kubovy M, van den Berg M. The whole is equal to the sum of its parts: A probabilistic model of grouping by proximity and similarity in regular patterns. Psychological Review. 2008; 115 :131–154. [ PubMed ] [ Google Scholar ]
• Kubovy M, Wagemans J. Grouping by proximity and multistability in dot lattices: A quantitative gestalt theory. Psychological Science. 1995; 6 :225–234. [ Google Scholar ]
• Lamme VAF. The neurophysiology of figure-ground segregation in primary visual cortex. Journal of Neuroscience. 1995; 15 :1605–1615. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Lashley KS, Chow KL, Semmes J. An examination of the electrical field theory of cerebral integration. Psychological Review. 1951; 58 :123–136. [ PubMed ] [ Google Scholar ]
• Lee S-H, Blake R. Visual form created solely from temporal structure. Science. 1999; 284 :1165–1168. [ PubMed ] [ Google Scholar ]
• Lee TS, Mumford D, Romero R, Lamme VAF. The role of the primary visual cortex in higher level vision. Vision Research. 1998; 38 :2429–2454. [ PubMed ] [ Google Scholar ]
• Leeuwenberg ELJ. Quantitative specification of information in sequential patterns. Psychological Review. 1969; 76 :216–220. [ PubMed ] [ Google Scholar ]
• Leeuwenberg ELJ. A perceptual coding language for visual and auditory patterns. American Journal of Psychology. 1971; 84 :307–349. [ PubMed ] [ Google Scholar ]
• Levitt JB, Lund JS. The spatial extent over which neurons in macaque striate cortex pool visual signals. Visual Neuroscience. 2002; 19 :439–452. [ PubMed ] [ Google Scholar ]
• Leyton M. Inferring causal history from shape. Cognitive Science. 1989; 13 :357–387. [ Google Scholar ]
• Li Z. A neural model of contour integration in the primary visual cortex. Neural Computation. 1998; 10 :903–940. [ PubMed ] [ Google Scholar ]
• Liu Z, Jacobs DW, Basri R. The role of convexity in perceptual completion: Beyond good continuation. Vision Research. 1999; 39 :4244–4257. [ PubMed ] [ Google Scholar ]
• Lowe DG. Perceptual organization and visual recognition. Boston, MA: Kluwer; 1985. [ Google Scholar ]
• Machilsen B, Pauwels M, Wagemans J. The role of vertical mirror symmetry in visual shape detection. Journal of Vision. 2009; 9 (12):11, 1–11. [ PubMed ] [ Google Scholar ]
• Machilsen B, Wagemans J. Integration of contour and surface information in shape detection. Vision Research. 2011; 51 :179–186. [ PubMed ] [ Google Scholar ]
• Marr D. Vision: A computational investigation into the human representation and processing of visual information. New York, NY: W. H. Freeman and Company; 1982. [ Google Scholar ]
• Marr D, Nishihara HK. Representation and recognition of the spatial organization of threedimensional shapes. Proceedings of the Royal Society of London. 1978; B200 :269–294. [ PubMed ] [ Google Scholar ]
• Martin DR, Fowlkes CC, Tal D, Malik J. Proceedings of the International Conference on Computer Vision. Vol. 2. Vancouver, BC: 2001. A database of human segmented natural images and its application to evaluating segmentation algorithms and measuring ecological statistics; pp. 416–423. [ Google Scholar ]
• Metelli F. The perception of transparency. Scientific American. 1974; 230 :90–98. [ PubMed ] [ Google Scholar ]
• Metzger W. Optische Untersuchungen am Ganzfeld. II. Zur Phänomenologie des homogenen Ganzfeldes [Optical investigations of the Ganzfeld. II. Toward the phenomenology of the homogeneous Ganzfeld] Psychologische Forschung. 1930; 13 :6–29. [ Google Scholar ]
• Metzger W. Beobachtungen über phänomenale Identität [Observations on phenomenal identity] Psychologische Forschung. 1934; 19 :1–60. [ Google Scholar ]
• Metzger W. Gesetze des Sehens. Frankfurt am Main, Germany: Kramer; 1936. (Translation reprinted as “Laws of seeing” (L. Spillmann, M. Wertheimer, & S. Lehar, Trans.) (2006). Cambridge, MA: MIT Press). [ Google Scholar ]
• Metzger W. Psychologie: Die Entwicklung ihrer Grundannahmen seit der Einführung des Experiments [Psychology: The development of basic principles since the introduction of the experimental method] Darmstadt, Germany: Verlag von Dr. Dietrich Steinkopff; 1941. [ Google Scholar ]
• Michotte A. In: The perception of causality. Miles TR, Miles E, translators. New York, NY: Basic Books; 1963. (Original work published 1946) [ Google Scholar ]
• Michotte A, Thinès G, Crabbé G. Les compléments amodaux des structures perceptives [Amodal completion of perceptual structures] Leuven, Belgium: Publications Universitaires de Louvain; 1964. [ Google Scholar ]
• Mihalas S, Dong Y, von der Heydt R, Niebur E. Mechanisms of perceptual organization provide auto-zoom and auto-localization for attention to objects. Proceedings of the National Academy of Sciences of the U.S.A. 2011; 108 :7583–7588. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Milner PM. A model for visual shape recognition. Psychological Review. 1974; 81 :521–535. [ PubMed ] [ Google Scholar ]
• Mitchison GJ, Westheimer G. The perception of depth in simple figures. Vision Research. 1984; 24 :1063–1073. [ PubMed ] [ Google Scholar ]
• Mohan R, Nevatia R. Perceptual organization for scene segmentation and description. IEEE Transactions on Pattern Analysis and Machine Intelligence. 1992; 14 :616–635. [ Google Scholar ]
• Mumford D. On the computational architecture of the neocortex: II. The role cortico-cortical loops. Biological Cybernetics. 1992; 66 :241–251. [ PubMed ] [ Google Scholar ]
• Nakayama K, Shimojo S, Silverman GH. Stereoscopic depth: Its relation to image segmentation, grouping, and the recognition of occluded objects. Perception. 1989; 18 :55–68. [ PubMed ] [ Google Scholar ]
• Navon D. Forest before trees: The precedence of global features in visual perception. Cognitive Psychology. 1977; 9 :353–383. [ Google Scholar ]
• Navon D. The effect of recognizability on figure-ground processing: Does it affect parsing or only figure selection? Quarterly Journal of Experimental Psychology. 2011; 64 :608–624. [ PubMed ] [ Google Scholar ]
• Nelson R, Palmer SE. Of holes and wholes: The perception of surrounded regions. Perception. 2001; 30 :1213–1226. [ PubMed ] [ Google Scholar ]
• Neumann H, Sepp W. Recurrent V1-V2 interaction in early visual boundary processing. Biological Cybernetics. 1999; 81 :425–444. [ PubMed ] [ Google Scholar ]
• Nygård GE, Sassi M, Wagemans J. The influence of orientation and contrast flicker on contour saliency of outlines of everyday objects. Vision Research. 2011; 51 :65–73. [ PubMed ] [ Google Scholar ]
• Nygård GE, Van Looy T, Wagemans J. The influence of orientation jitter and motion on contour saliency and object identification. Vision Research. 2009; 49 :2475–2484. [ PubMed ] [ Google Scholar ]
• Orbison WD. Shape as a function of the vector-field. American Journal of Psychology. 1939; 52 :31–45. [ Google Scholar ]
• Oyama T. Perceptual grouping as a function of proximity. Perceptual and Motor Skills. 1961; 13 :305–306. [ Google Scholar ]
• Oyama T, Simizu M, Tozawa J. Effects of similarity on apparent motion and perceptual grouping. Perception. 1999; 28 :739–748. [ PubMed ] [ Google Scholar ]
• Palmer SE. Hierarchical structure in perceptual representation. Cognitive Psychology. 1977; 9 :441–474. [ Google Scholar ]
• Palmer SE. Common region: A new principle of perceptual organization. Cognitive Psychology. 1992; 24 :436–447. [ PubMed ] [ Google Scholar ]
• Palmer SE. Perceptual organization in vision. In: Pashler H, editor. Stevens handbook of experimental psychology: Vol. 1Sensation and perception. 3rd ed. New York, NY: Wiley; 2002a. pp. 177–234. [ Google Scholar ]
• Palmer SE. Perceptual grouping: It is later than you think. Current Directions in Psychological Science. 2002b; 11 :101–106. [ Google Scholar ]
• Palmer SE. Perceptual organization and grouping. In: Kimchi R, Behrmann M, Olson CR, editors. Perceptual organization in vision: Behavioral and neural perspectives. Mahwah, NJ: Erlbaum; 2003. pp. 3–43. [ Google Scholar ]
• Palmer SE, Beck D. The repetition discrimination task: An objective method for studying perceptual grouping. Attention, Perception, & Psychophysics. 2007; 69 :68–78. [ PubMed ] [ Google Scholar ]
• Palmer SE, Brooks JL. Edge-region grouping in figure-ground organization and depth perception. Journal of Experimental Psychology: Human Perception & Performance. 2008; 34 :1353–1371. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Palmer SE, Brooks JL, Nelson R. When does grouping happen? Acta Psychologica. 2003; 114 :311–330. [ PubMed ] [ Google Scholar ]
• Palmer SE, Ghose T. Extremal edges: A powerful cue to depth perception and figure-ground organization. Psychological Science. 2008; 19 :77–84. [ PubMed ] [ Google Scholar ]
• Palmer SE, Neff J, Beck D. Late influences on perceptual grouping: Amodal completion. Psychonomic Bulletin & Review. 1996; 3 :75–80. [ PubMed ] [ Google Scholar ]
• Palmer SE, Nelson R. Late influences on perceptual grouping: Illusory figures. Perception & Psychophysics. 2000; 62 :1321–1331. [ PubMed ] [ Google Scholar ]
• Palmer SE, Rock I. Rethinking perceptual organization: The role of uniform connectedness. Psychonomic Bulletin & Review. 1994; 1 :29–55. [ PubMed ] [ Google Scholar ]
• Panis S, Wagemans J. Time-course contingencies in perceptual organization and identification of fragmented object outlines. Journal of Experimental Psychology: Human Perception & Performance. 2009; 35 :661–687. [ PubMed ] [ Google Scholar ]
• Pantle A, Picciano L. A multistable movement display: Evidence for two separate motion systems in human vision. Science. 1976; 193 :500–502. [ PubMed ] [ Google Scholar ]
• Parent P, Zucker SW. Trace inference, curvature consistency, and curve detection. IEEE Transactions on Pattern Analysis and Machine Intelligence. 1989; 11 :823–839. [ Google Scholar ]
• Pasupathy A, Connor CE. Responses to contour features in macaque area V4. Journal of Neurophysiology. 1999; 82 :2490–2502. [ PubMed ] [ Google Scholar ]
• Peterhans E, von der Heydt R. Mechanisms of contour perception in monkey visual cortex. II. Contours bridging gaps. Journal of Neuroscience. 1989; 9 :1749–1763. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Peterson MA. The proper placement of uniform connectedness. Psychonomic Bulletin & Review. 1994; 1 :509–514. [ PubMed ] [ Google Scholar ]
• Peterson MA, Enns JT. The edge complex: Implicit memory for figure assignment in shape perception. Perception & Psychophysics. 2005; 67 :727–740. [ PubMed ] [ Google Scholar ]
• Peterson MA, Gibson BS. Must figure-ground organization precede object recognition? An assumption in peril. Psychological Science. 1994a; 5 :253–259. [ Google Scholar ]
• Peterson MA, Gibson BS. Object recognition contributions to figure-ground organization: Operations on outlines and subjective contours. Perception & Psychophysics. 1994b; 56 :551–564. [ PubMed ] [ Google Scholar ]
• Peterson MA, Harvey EM, Weidenbacher HJ. Shape recognition contributions to figure-ground reversal: Which route counts. Journal of Experimental Psychology: Human Perception and Performance. 1991; 17 :1075–1089. [ PubMed ] [ Google Scholar ]
• Peterson MA, Lampignano DW. Implicit memory for novel figure-ground displays includes a history of cross-border competition. Journal of Experimental Psychology: Human Perception and Performance. 2003; 29 :808–822. [ PubMed ] [ Google Scholar ]
• Peterson MA, Salvagio E. Inhibitory competition in figure-ground perception: Context and convexity. Journal of Vision. 2008; 8 (16):4, 1–13. [ PubMed ] [ Google Scholar ]
• Peterson MA, Skow E. Inhibitory competition between shape properties in figure-ground perception. Journal of Experimental Psychology: Human Perception and Performance. 2008; 34 :251–267. [ PubMed ] [ Google Scholar ]
• Pinna B. New Gestalt principles of perceptual organization: An extension from grouping to shape and meaning. Gestalt Theory. 2010; 32 :11–78. [ Google Scholar ]
• Pomerantz JR, Kubovy M. Theoretical approaches to perceptual organization: Simplicity and likelihood principles. In: Boff KR, Kaufman L, Thomas JP, editors. Handbook of perception and human performance. New York, NY: Wiley; 1986. pp. 36–46. 36-1. [ Google Scholar ]
• Pomerantz JR, Sager LC, Stoever RJ. Perception of wholes and their component parts: Some configurational superiority effects. Journal of Experimental Psychology: Human Perception and Performance. 1977; 3 :422–435. [ PubMed ] [ Google Scholar ]
• Qiu FT, Sugihara T, von der Heydt R. Figure-ground mechanisms provide structure for selective attention. Nature Neuroscience. 2007; 10 :1492–1499. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Qiu FT, von der Heydt R. Figure and ground in the visual cortex: V2 combines stereoscopic cues with Gestalt rules. Neuron. 2005; 47 :155–166. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Qiu FT, von der Heydt R. Neural representation of transparent overlay. Nature Neuroscience. 2007; 10 :283–284. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Quinlan PT, Wilton RN. Grouping by proximity or similarity? Competition between the Gestalt principles in vision. Perception. 1998; 27 :417–430. [ PubMed ] [ Google Scholar ]
• Quinn PC, Bhatt RS. Learning perceptual organization in infancy. Psychological Science. 2005; 16 :511–515. [ PubMed ] [ Google Scholar ]
• Quinn PC, Bhatt RS. Are some Gestalt principles deployed more readily than others during early development? The case of lightness versus form similarity. Journal of Experimental Psychology: Human Perception and Performance. 2006; 32 :1221–1230. [ PubMed ] [ Google Scholar ]
• Rausch E. Über Summativität und Nichtsummativität [On summativity and nonsummativity] Psychologische Forschung. 1937; 21 :209–289. [ Google Scholar ]
• Rensink RA, Enns JT. Preemption effects in visual search: Evidence for low-level grouping. Psychological Review. 1995; 102 :101–130. [ PubMed ] [ Google Scholar ]
• Ringach DL, Shapley R. Spatial and temporal properties of illusory contours and amodal boundary completion. Vision Research. 1996; 36 :3037–3050. [ PubMed ] [ Google Scholar ]
• Rock I, Brosgole L. Grouping based on phenomenal proximity. Journal of Experimental Psychology. 1964; 67 :531–538. [ PubMed ] [ Google Scholar ]
• Rock I, Nijhawan R, Palmer SE, Tudor L. Grouping based on phenomenal similarity of achromatic color. Perception. 1992; 21 :779–789. [ PubMed ] [ Google Scholar ]
• Roelfsema PR. Cortical algorithms for perceptual grouping. Annual Review of Neuroscience. 2006; 29 :203–277. [ PubMed ] [ Google Scholar ]
• Roelfsema PR, Lamme VAF, Spekreijse H. Object-based attention in the primary visual cortex of the macaque monkey. Nature. 1998; 395 :376–381. [ PubMed ] [ Google Scholar ]
• Roelfsema PR, Lamme VAF, Spekreijse H. The implementation of visual routines. Vision Research. 2000; 40 :1385–1411. [ PubMed ] [ Google Scholar ]
• Roelfsema PR, Lamme VAF, Spekreijse H, Bosch H. Figure-ground segregation in a recurrent network architecture. Journal of Cognitive Neuroscience. 2002; 14 :525–537. [ PubMed ] [ Google Scholar ]
• Roelfsema PR, Scholte HS, Spekreijse H. Temporal constraints on the grouping of contour segments into spatially extended objects. Vision Research. 1999; 39 :1509–1529. [ PubMed ] [ Google Scholar ]
• Rossi AF, Desimone R, Ungerleider LG. Contextual modulation in primary visual cortex of macaques. Journal of Neuroscience. 2001; 21 :1698–1709. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Rubin E. Synsoplevede Figurer. Studier i psykologisk Analyse /Visuell wahrgenommene Figuren. Studien in psychologischer Analyse [Visually perceived figures. Studies in psychological analysis] Copenhagen, Denmark/Berlin, Germany: Gyldendalske Boghandel.; 1915. [ Google Scholar ]
• Rubin E. Visuell wahrgenommene wirkliche bewegungen [Visually perceived genuine motions] Zeitschrift für Psychologie. 1927; 103 :354–384. [ Google Scholar ]
• Rush GP. Visual grouping in relation to age. Archives of Psychology. 1937; 31 :1–95. [ Google Scholar ]
• Rust NC, DiCarlo JJ. Selectivity and tolerance (“invariance”) both increase as visual information propagates from cortical area V4 to IT. Journal of Neuroscience. 2010; 30 :12978–12995. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Sagara M, Oyama T. Experimental studies on figural after-effects in Japan. Psychological Bulletin. 1957; 54 :327–338. [ PubMed ] [ Google Scholar ]
• Sajda P, Finkel LH. Intermediate-level visual representations and the construction of surface perception. Journal of Cognitive Neuroscience. 1995; 7 :267–291. [ PubMed ] [ Google Scholar ]
• Sasaki Y. Processing local signals into global patterns. Current Opinion in Neurobiology. 2007; 17 :132–139. [ PubMed ] [ Google Scholar ]
• Sassi M, Vancleef K, Machilsen B, Panis S, Wagemans J. Identification of everyday objects on the basis of Gaborized outline versions. i-Perception. 2010; 1 :121–142. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Schulz MF, Sanocki T. Time course of perceptual grouping by color. Psychological Science. 2003; 14 :26–30. [ PubMed ] [ Google Scholar ]
• Schumann F. Beiträge zur Analyse der GesichtswahrnehmungenIEinige Beobachtungen über die Zusammenfassung von Gesichtseindrücken zu Einheiten [Contributions to the analysis of visual perceptionISome observations on the combination of visual impressions into units] Zeitschrift für Psychologie und Physiologie der Sinnesorgane. 1900; 23 :1–32. [ Google Scholar ]
• Sejnowski TJ, Hinton GE. Separating figure from ground with a Boltzmann machine. In: Arbib MA, Hanson A, editors. Vision, brain, and cooperative computation. Cambridge, MA: MIT Press; 1987. pp. 703–724. [ Google Scholar ]
• Sekuler AB, Bennett PJ. Generalized common fate: Grouping by common luminance changes. Psychological Science. 2001; 12 :437–444. [ PubMed ] [ Google Scholar ]
• Sekuler R. Motion perception: A modern view of Wertheimer’s 1912 monograph. Perception. 1996; 25 :1243–1258. [ PubMed ] [ Google Scholar ]
• Sha’ashua A, Ullman S. Proceedings of the Second International Conference on Computer Vision. Tampa, FL: 1988. Structural saliency: The detection of globally salient structures using a locally connected network; pp. 321–327. [ Google Scholar ]
• Shadlen MN, Movshon JA. Synchrony unbound: A critical evaluation of the temporal binding hypothesis. Neuron. 1999; 24 :67–77. [ PubMed ] [ Google Scholar ]
• Shimojo S, Silverman GH, Nakayama K. Occlusion and the solution to the aperture problem for motion. Vision Research. 1989; 29 :619–626. [ PubMed ] [ Google Scholar ]
• Sigman M, Cecchi GA, Gilbert CD, Magnasco MO. On a common circle: Natural scenes and Gestalt rules. Proceedings of the National Academy of Sciences of the U. S. A. 2001; 98 :1935–1940. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Singer W, Gray CM. Visual feature integration and the temporal correlation hypothesis. Annual Review of Neuroscience. 1995; 18 :555–586. [ PubMed ] [ Google Scholar ]
• Singh M. Modal and amodal completion generate different shapes. Psychological Science. 2004; 15 :454–459. [ PubMed ] [ Google Scholar ]
• Singh M, Fulvio JM. Visual extrapolation of contour geometry. Proceedings of the National Academy of Sciences of the U. S. A. 2005; 102 :939–944. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Singh M, Fulvio JM. Bayesian contour extrapolation: Geometric determinants of good continuation. Vision Research. 2007; 47 :783–798. [ PubMed ] [ Google Scholar ]
• Singh M, Hoffman DD. Part-based representations of visual shape and implications for visual cognition. In: Shipley TF, Kellman PJ, editors. From fragments to objects: Segmentation and grouping in vision. Advances in Psychology Series. Vol. 130. New York, NY: Elsevier Science; 2001. pp. 401–459. [ Google Scholar ]
• Sinico M. Demonstration in experimental phenomenology: How to bring out perceptual laws. Theory & Psychology. 2008; 18 :853–863. [ Google Scholar ]
• Spehar B. The role of contrast polarity in perceptual closure. Vision Research. 2002; 42 :343–350. [ PubMed ] [ Google Scholar ]
• Sperry RW, Miner N, Myers RE. Visual pattern perception following subpial slicing and tantalum wire implantations in the visual cortex. Journal of Comparative and Physiological Psychology. 1955; 48 :50–58. [ PubMed ] [ Google Scholar ]
• Spillmann L. From elements to perception: Local and global processing in visual neurons. Perception. 1999; 28 :1461–1492. [ PubMed ] [ Google Scholar ]
• Spillmann L. Phenomenology and neurophysiological correlations: Two approaches to perception research. Vision Research. 2009; 49 :1507–1521. [ PubMed ] [ Google Scholar ]
• Stahl JS, Wang S. Globally optimal grouping for symmetric closed boundaries by combining boundary and region information. IEEE Transactions on Pattern Analysis and Machine Intelligence. 2008; 30 :395–411. [ PubMed ] [ Google Scholar ]
• Steinman RM, Pizlo Z, Pizlo FJ. Phi is not beta, and why Wertheimer’s discovery launched the Gestalt revolution. Vision Research. 2000; 40 :2257–2264. [ PubMed ] [ Google Scholar ]
• Takeichi H, Nakazawa H, Murakami I, Shimojo S. The theory of the curvature-constraint line for amodal completion. Perception. 1995; 24 :373–389. [ PubMed ] [ Google Scholar ]
• Ternus J. Experimentelle Untersuchungen über phänomenale Identität. Psychologische Forschung. 1926; 7 :81–136. (Translated extract reprinted as “The problem of phenomenal identity”. In W. D. Ellis (Ed.), (1938). A source book of Gestalt psychology (pp. 149–160). London, U. K.: Routledge & Kegan Paul Ltd.). [ Google Scholar ]
• Treisman A, Gelade G. A feature-integration theory of attention. Cognitive Psychology. 1980; 12 :97–136. [ PubMed ] [ Google Scholar ]
• Trujillo LT, Allen JJB, Schnyer DM, Peterson MA. Neurophysiological evidence for the influence of past experience on figure–ground perception. Journal of Vision. 2010; 10 (2):5, 1–21. [ PubMed ] [ Google Scholar ]
• Tse PU. Complete mergeability and amodal completion. Acta Psychologica. 1999; 102 :165–201. [ PubMed ] [ Google Scholar ]
• Tversky T, Geisler WS, Perry JS. Contour grouping: Closure effects are explained by good continuation and proximity. Vision Research. 2004; 44 :2769–2777. [ PubMed ] [ Google Scholar ]
• Ullman S. Filling-in the gaps: the shape of subjective contours and a model for their generation. Biological Cybernetics. 1976; 25 :1–6. [ Google Scholar ]
• Ullman S. The interpretation of visual motion. Cambridge, MA: MIT Press; 1979. [ Google Scholar ]
• van den Berg M, Kubovy M, Schirillo JA. Grouping by regularity and the perception of illumination. Vision Research. 2011; 51 :1360–1371. [ PubMed ] [ Google Scholar ]
• van Lier R. Investigating global effects in visual occlusion: From a partly occluded square to a treetrunk's rear. Acta Psychologica. 1999; 102 :203–220. [ PubMed ] [ Google Scholar ]
• van Lier RJ, van der Helm PA, Leeuwenberg ELJ. Integrating global and local aspects of visual occlusion. Perception. 1994; 23 :883–903. [ PubMed ] [ Google Scholar ]
• van Lier RJ, van der Helm PA, Leeuwenberg ELJ. Competing global and local completions in visual occlusion. Journal of Experimental Psychology: Human Perception and Performance. 1995; 21 :571–583. [ PubMed ] [ Google Scholar ]
• Vecera SP. The reference frame of figure-ground assignment. Psychonomic Bulletin & Review. 2004; 11 :909–915. [ PubMed ] [ Google Scholar ]
• Vecera SP, Farah MJ. Is visual image segmentation a bottom-up or an interactive process? Perception & Psychophysics. 1997; 59 :1280–1296. [ PubMed ] [ Google Scholar ]
• Vecera SP, Flevaris AV, Filapek JC. Exogenous spatial attention influences figure-ground assignment. Psychological Science. 2004; 15 :20–26. [ PubMed ] [ Google Scholar ]
• Vecera SP, Palmer SE. Grounding the figure: Contextual effects of depth planes on figure-ground organization. Psychonomic Bulletin & Review. 2006; 13 :563–569. [ PubMed ] [ Google Scholar ]
• Vecera SP, Vogel EK, Woodman GF. Lower region: A new cue for figure-ground assignment. Journal of Experimental Psychology: General. 2002; 13 :194–205. [ PubMed ] [ Google Scholar ]
• Vezzani S, Marino BFM, Giora E. An early history of the Gestalt factors of organization. Perception. 2012; 41 (2):148–167. [ PubMed ] [ Google Scholar ]
• Vickery TJ, Jiang YV. Associative grouping: Perceptual grouping of shapes by association. Attention, Perception & Psychophysics. 2009; 71 :896–909. [ PubMed ] [ Google Scholar ]
• von der Heydt R, Peterhans E, Baumgartner G. Illusory contours and cortical neuron responses. Science. 1984; 224 :1260–1262. [ PubMed ] [ Google Scholar ]
• von der Malsburg C. The correlation theory of brain function. (Departmental Technical Report No. 81-2) Göttingen, Germany: Max-Planck-Institut für Biophysical Chemistry; 1981. [ Google Scholar ]
• von Ehrenfels C. Über "Gestaltqualitäten". Vierteljahrsschrift für wissenschaftliche Philosophie. 1890; 14 :224–292. (Translated as “On ‘Gestalt qualities’”. In B. Smith (Ed. & Trans.), (1988). Foundations of Gestalt theory (pp. 82–117). Munich, Germany/Vienna, Austria: Philosophia Verlag.) [ Google Scholar ]
• Wagemans J. Perceptual use of nonaccidental properties. Canadian Journal of Psychology. 1992; 46 :236–279. [ PubMed ] [ Google Scholar ]
• Wagemans J. Skewed symmetry: A nonaccidental property used to perceive visual forms. Journal of Experimental Psychology: Human Perception and Performance. 1993; 19 :364–380. [ PubMed ] [ Google Scholar ]
• Wagemans J, Feldman J, Gepshtein S, Kimchi R, Pomerantz JR, van der Helm P, van Leeuwen C. A century of Gestalt psychology in visual perception: II. Conceptual and theoretical foundations. Psychological Bulletin. 2012 in press. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Wagemans J, van Lier R, Scholl BJ, editors. Introduction to Michotte’s heritage in perception and cognition research. Acta Psychologica. 2006; 123 :1–19. [ PubMed ] [ Google Scholar ]
• Wallace J, Scott-Samuel N. Spatial versus temporal grouping in a modified Ternus display. Vision Research. 2007; 47 :2353–2366. [ PubMed ] [ Google Scholar ]
• Wannig A, Stanisor L, Roelfsema PR. Automatic spread of attentional response modulation along Gestalt criteria in primary visual cortex. Nature Neuroscience. 2011; 14 :1243–1244. [ PubMed ] [ Google Scholar ]
• Wertheimer M. Experimentelle Studien über das Sehen von Bewegung. Zeitschrift für Psychologie. 1912; 61 :161–265. (Translated extract reprinted as “Experimental studies on the seeing of motion”. In T. Shipley (Ed.), (1961). Classics in psychology (pp. 1032–1089). New York, NY: Philosophical Library.) [ Google Scholar ]
• Wertheimer M. Untersuchungen zur Lehre von der Gestalt, I: Prinzipielle Bemerkungen. Psychologische Forschung. 1922; 1 :47–58. (Translated extract reprinted as “The general theoretical situation”. In W. D. Ellis (Ed.), (1938). A source book of Gestalt psychology (pp. 12–16). London, U. K.: Routledge & Kegan Paul Ltd.) [ Google Scholar ]
• Wertheimer M. Untersuchungen zur Lehre von der Gestalt, II. Psychologische Forschung. 1923; 4 :301–350. (Translated extract reprinted as “Laws of organization in perceptual forms.” In W. D. Ellis (Ed.), (1938). A source book of Gestalt psychology (pp. 71–94). London, U. K.: Routledge & Kegan Paul Ltd.). [ Google Scholar ]
• Wertheimer M. Über Gestalttheorie . Lecture delivered to the Kant-Gesellschaft, Berlin, December 1924. 1924 (Translated extract reprinted as “Gestalt theory”. In W. D. Ellis (Ed.), (1938). A source book of Gestalt psychology (pp. 1–11). London, U. K.: Routledge & Kegan Paul Ltd.) [ Google Scholar ]
• Wertheimer M. Productive thinking. New York, NY: Harper & Brothers Publishers; 1945. [ Google Scholar ]
• Westheimer G. Gestalt theory reconfigured: Max Wertheimer’s anticipation of recent developments on visual neuroscience. Perception. 1999; 28 :5–15. [ PubMed ] [ Google Scholar ]
• Williams LR, Jacobs DW. Stochastic completion fields: A neural model of illusory contour shape and salience. Neural Computation. 1997; 9 :837–858. [ PubMed ] [ Google Scholar ]
• Yen SC, Finkel LH. Extraction of perceptually salient contours by striate cortical networks. Vision Research. 1998; 38 :719–741. [ PubMed ] [ Google Scholar ]
• Yin C, Kellman PJ, Shipley TF. Surface integration influences depth discrimination. Vision Research. 2000; 40 :1969–1978. [ PubMed ] [ Google Scholar ]
• Zhang NR, von der Heydt R. Analysis of the context integration mechanisms underlying figureground organization in the visual cortex. Journal of Neuroscience. 2010; 30 :6482–6496. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Zhaoping L. Border-ownership from intracortical interactions in visual area V2. Neuron. 2005; 47 :143–153. [ PubMed ] [ Google Scholar ]
• Zhou H, Friedman HS, von der Heydt R. Coding of border-ownership in monkey visual cortex. Journal of Neuroscience. 2000; 20 :6594–6611. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Zhou J, Tjan BS, Zhou Y, Liu Z. Better discrimination for illusory than for occluded perceptual completions. Journal of Vision. 2008; 8 :7, 26, 1–17. [ PubMed ] [ Google Scholar ]
• Zipser K, Lamme VAF, Schiller PH. Contextual modulation in primary visual cortex. Journal of Neuroscience. 1996; 16 :7376–7389. [ PMC free article ] [ PubMed ] [ Google Scholar ]

Gestalt Therapy Explained: History, Definition and Examples

These terms have become part of the cultural lexicon, yet few know that their roots come from gestalt therapy.

Gestalt therapy is an influential and popular form of therapy that has had an impact on global culture and society. It is an amalgamation of different theories and techniques, compiled and refined over the years by many people, most notably its founder, Fritz Perls.

Although gestalt therapy is often considered a “fringe therapy,” it is applicable in diverse settings, from the clinic to the locker room to the boardroom. Read on for an introduction to this exciting therapy.

Before you continue, we thought you might like to download our three Positive CBT Exercises for free . These science-based exercises will provide you with detailed insight into Positive CBT and give you the tools to apply it in your therapy or coaching.

This Article Contains:

Gestalt therapy defined, a brief history: the 3 founders of gestalt therapy, 4 key concepts and principles, the empty chair technique, examples of gestalt therapy, criticisms and limitations, 3 books on the topic, a take-home message.

Gestalt therapy is a bulky concept to define. Let’s start with a definition by Charles Bowman (1998, p. 106), a gestalt therapy scholar and practitioner. We’ll present the full definition and then break down its parts:

Gestalt therapy is a process psychotherapy with the goal of improving one’s contact in community and with the environment in general. This goal is accomplished through aware, spontaneous and authentic dialogue between client and therapist. Awareness of differences and similarities [is] encouraged while interruptions to contact are explored in the present therapeutic relationship.

Let’s break it down into three components:

Gestalt therapy is a process psychotherapy with the goal of improving one’s contact in community and with the environment in general . A process psychotherapy is one that focuses on process over discrete events. This means that gestalt therapists are more interested in the process as a whole, rather than individual events or experiences.

This goal is accomplished through aware, spontaneous and authentic dialogue between client and therapist . Gestalt psychotherapists use a relational, here-and-now framework , meaning that they prioritize the current interactions with the client over history and past experience.

And finally: Awareness of differences and similarities [is] encouraged while interruptions to contact are explored in the present therapeutic relationship . Gestalt therapy draws upon dialectical thinking and polarization to help the client achieve balance, equilibrium, contact, and health. We will explore these concepts in greater depth later in this post.

Gestalt therapy borrows heavily from psychoanalysis , Gestalt psychology, existential philosophy, zen Buddhism, Taoism, and more (Bowman, 2005). It is an amalgamation of different theoretical ideas, packaged for delivery to patients using the traditional psychoanalytic therapy situation, and also includes elements from more fringe elements of psychology, such as psychodrama and role-playing .

It is tempting to buy into the “great man theory” of gestalt therapy and give all of the credit to Fritz Perls; however, the story is more nuanced than this (Bowman, 2005). Gestalt therapy is the result of many people’s contributions. Since this is a brief article, we will focus on three founders: Fritz Perls, Laura Perls, and Paul Goodman.

Gestalt therapy originated in Germany in the 1930s. Fritz and Laura Perls were psychoanalysts in Frankfurt and Berlin. The Perlses’ ideas differed from Freud’s so radically that they broke off and formed their own discipline.

In 1933 they fled Nazi Germany and moved to South Africa, where they formulated much of gestalt therapy. They eventually moved to New York and wrote the book on gestalt therapy with the anarchist writer and gestalt therapist Paul Goodman (Wulf, 1996).

Download 3 Free Positive CBT Exercises (PDF)

These detailed, science-based exercises will equip you or your clients with tools to find new pathways to reduce suffering and more effectively cope with life stressors.

Download 3 Free Positive CBT Tools Pack (PDF)

By filling out your name and email address below.

‘Whole’ + Health + Awareness + Responsibility:

The German word gestalt has no perfect English translation, but a close approximation is “whole.”

Gestalt therapy is based on gestalt psychology, a discipline of experimental psychology founded in Germany in 1912. Gestalt psychologists argued that human beings perceive entire patterns or configurations, not merely individual components.

This is why when we see a group of dots arranged as a triangle, we see a triangle instead of random dots. Our brains organize information into complete configurations, or gestalts (O’Leary, 2013).

Additionally, the individual is thought of as being involved in a constant construction of gestalts, organizing and reorganizing their experience, searching for patterns and a feeling of wholeness. Gestalt therapy associates feeling whole with feeling alive and connected to one’s own unique experience of existence.

Gestalt therapists apply this philosophy of wholeness to their clients. They believe that a human being cannot be understood by generalizing one part of the self to understand the whole person (O’Leary, 2013). For example, the client cannot be understood solely by their diagnosis, or by one interaction, but must be considered the total of all they are.

To understand what it means to be healthy in gestalt therapy, we must first understand the ideas of figure and ground. To illustrate, let’s use an image called the Rubin Vase.

There is a black outline of a vase on the screen, and at first, this is all the viewer notices, but after a moment, the viewer’s attention shifts and they notice the two faces outlined in the white part of the screen, one on either side of the vase.

In the first perception, the black vase is called the figure, and the white faces are called the ground. But the viewer can shift their attention, and through this act, the figure and ground switch, with the white faces becoming the figure, and the black vase the ground.

Gestalt therapists apply this perceptual phenomenon to human experience. Going through the world, we are engaged in a constant process of differentiating figures and grounds. The figure is whatever we are paying attention to, while the ground is whatever is happening in the background. Healthy functioning is the ability to attend flexibly to the figure that is most important at the time (O’Leary, 2013).

Gestalt therapy sees healthy living is a series of creative adjustments (Latner, 1973, p. 54). This means adjusting one’s behavior, naturally and flexibly, to the figure in awareness.

Here is another example of this process: As I am writing, I realize that my lips are dry and my mouth is parched. I get up, pour a glass of water, and then return to my writing. In response to my feeling of thirst, I shift my frame of awareness from my writing, to drinking water, and then back to my writing. The act of drinking water, satisfying my thirst, completes the gestalt, and I am free to return to my work.

In contrast, unhealthy living results when one’s attention flits from one figure to the other without ever achieving wholeness.

An easy example of this can be seen through our relationships with our phones. If we are working on something important and our phone rings, we can make a decision to ignore it for the moment, finish our work, and then call the person back later. If there is a deadline for our project, this may be the healthy choice. But if we allow our attention to be divided each time our phone rings, we may never finish our project.

Healthy living requires the individual to attend flexibly and intentionally to the most crucial figure in their awareness.

3. Awareness

Although we cannot help but live in the present, it is clear to anyone living that we can direct our attention away from it. Gestalt therapists prioritize present moment awareness and the notion that paying attention to the events unfolding in the here-and-now is the way to achieve healthy living.

Awareness allows for the figure/ground differentiation process to work naturally, helping us form gestalts, satisfy our needs, and make sense of our experience (Latner, 1973, p. 72). Awareness is both the goal and the methodology of gestalt therapy (O’Leary, 2013).

Therapists use what is present in the here-and-now, including actions, posture, gesticulations, tone of voice, and how the client relates to them, to inform their work (O’Leary, 2013). The past is thought of as significant insofar as it exists in the present (O’Leary, 2013).

Gestalt therapists focus on helping their clients restore their natural awareness of the present moment by focusing on the here-and-now in the therapy room. Experiences and feelings that have not been fully processed in the past are revisited and worked through in the present, such as with the empty chair technique, explored later in this post.

4. Responsibility

In gestalt therapy, there are two ways of thinking about responsibility. According to Latner (1973, p. 70), we are responsible when we are “ aware of what is happening to us ” and when we “ own up to acts, impulses, and feelings. ” Gestalt therapists help their clients take both kinds of personal responsibility.

When therapy begins, clients do not internalize feelings, emotions, or problems, often externalizing and shifting responsibility for their actions as the fault or consequence of others (O’Leary, 2013). They may be stuck in the past, ruminating on mistakes or regrets about their actions.

When clients are better able to take responsibility for themselves, they come to realize how much they can do for themselves (O’Leary, 2013).

To do this, clients must have an awareness of what is happening to them in the present moment, as well as awareness of their part of the interaction. Increasing this type of awareness, completing past experiences, and encouraging new and flexible behaviors are some of the ways that gestalt therapists help their clients take personal responsibility.

Things that are in our awareness but incomplete are called “ unfinished business .” Because of our natural tendency to make gestalts, unfinished business can be a significant drain of energy, as well as a block on future development (O’Leary, 2013).

The most popular and well-known technique in gestalt therapy, the empty chair technique or empty chair dialogue (ECH), is a method of resolving unfinished business in the therapy room.

Unfinished business is often the result of unexpressed emotion, such as not grieving a loss (O’Leary, 2013), and/or unfulfilled needs, such as unaired grievances in a relationship. The client may have chosen to avoid the unfinished business in the moment, deciding not to rock the boat or to preserve the relationship.

After the fact, these unexpressed feelings may lack a suitable outlet or may continue to be avoided because of shame or fear of being vulnerable. Most people tend to avoid these painful feelings instead of doing what is necessary to change (Perls, 1969).

The empty chair technique is a way of bringing unexpressed emotion and unfulfilled needs into the here-and-now. In ECH, the therapist sets up two chairs for the client, one of which is left empty. The client sits in one chair and imagines the significant other with whom they have unfinished business in the empty chair.

The client is then instructed and helped to say what was left unsaid to the imaginary significant other. Sometimes the client switches chairs and speaks to themselves as though they were the significant other. Through this dialogue, the client’s past emotions are brought into the present. They are then processed and worked through with the therapist.

This technique can be done with either an ongoing relationship or a relationship that has ended. The resolution of the work is to help the client shift their self-perception. Clients undergoing ECH may shift from viewing themselves as weak and victimized to a place of greater self-empowerment. They may see the significant other with greater understanding or hold them accountable for harm (Paivio & Greenberg, 1995).

World’s Largest Positive Psychology Resource

The Positive Psychology Toolkit© is a groundbreaking practitioner resource containing over 500 science-based exercises , activities, interventions, questionnaires, and assessments created by experts using the latest positive psychology research.

Updated monthly. 100% Science-based.

“The best positive psychology resource out there!” — Emiliya Zhivotovskaya , Flourishing Center CEO

Gestalt therapy is used in a variety of settings, from the clinic to the corporate boardroom (Leahy & Magerman, 2009). Gestalt institutes exist all over the world, and the approach is practiced in inpatient clinics and private practices in individual and group therapy . Because of this variety of applications, it can take many forms.

In 1965 the American Psychological Association filmed a series called “ Three Approaches to Psychotherapy ,” featuring Fritz Perls (gestalt therapy), Carl Rogers ( person-centered therapy ), and Albert Ellis ( rational emotive behavior therapy ), demonstrating their approaches with a patient named Gloria.

To see what gestalt therapy looks like, you can watch this video of Perls working in real time. In the video, Perls describes his approach, works with Gloria for a brief session, and then debriefs the viewer at the end.

Much of the criticism in the literature focuses on Fritz Perls, the larger-than-life founder of gestalt therapy. Perls had a powerful personality and left a deep personal imprint on the therapy that he developed. Indeed, his own limitations may have limited the therapy.

Perls struggled with interpersonal relationships throughout his life. In turn, the therapy he helped create focused on the ideas of separateness, personal responsibility, and self-support as ideal ways of being (Dolliver, 1981).

One criticism of Perls’s work of spreading gestalt therapy to lay audiences is that he focused on specific techniques that he could demonstrate on film or in live demonstrations.

These demonstrations elevated Perls to guru status and also encouraged practitioners to apply his techniques piece-meal, without understanding the underlying theory of gestalt therapy. This had the overall effect of watering down the method as a whole (Janov, 2005).

Another critique is that Perls’s gestalt therapy focused on helping clients to have “honest interactions” with others. In contrast, he maintained a strict focus on the client’s experience, leaving himself out of the room by avoiding personal questions, turning them back on the client (Dolliver, 1981).

Recent gestalt therapists have revised this aspect, bringing more of themselves into the room and answering their clients’ questions when there could be therapeutic value in doing so.

Perls also emphasized “total experiencing,” yet he de-emphasized the client’s past and kept the focus of the work strictly on the present. He also emphasized “ living as one truly is ,” but in the room, he relied upon reenactment and role-play, which he strictly controlled (Janov, 2005).

Gestalt therapy promotes a specific way of living, and therapists need to be mindful of whether encouraging these behaviors and values in their client is actually in their best interest. By adopting an explicit focus on helping clients “ become who they truly are ,” Perls denied his part in shaping what parts of themselves clients felt free to express in the therapy (Dolliver, 1981).

Gestalt therapists have spent a long time living in Perls’s shadow. New therapists would be better served by learning the theory and practicing without trying to imitate Perls’s style, pushing forward and altering the therapy to make it a better fit for their methods and the needs of their clients.

To practice gestalt therapy effectively and cohesively, rather than as a disconnected set of techniques and quick fixes, it is crucial to have a good understanding of the underlying theory as well as the historical antecedents that it is based on (Bowman, 2005).

17 Science-Based Ways To Apply Positive CBT

These 17 Positive CBT & Cognitive Therapy Exercises [PDF] include our top-rated, ready-made templates for helping others develop more helpful thoughts and behaviors in response to challenges, while broadening the scope of traditional CBT.

Created by Experts. 100% Science-based.

These three books discuss Gestalt Therapy more in-depth.

1. Gestalt Therapy: Excitement and Growth in the Human Personality –  Fritz Perls, Ralph Hefferline, and Paul Goodman

This book, written in 1951, is the original textbook describing gestalt theory and practice. If you are interested in going to the source before examining a more modern perspective, this is the book for you.

Available on Amazon .

2. The Gestalt Therapy Book –  Joel Latner

If you are interested in a brief overview of gestalt therapy, as well as a snapshot of the field in the 1970s, this book is a good choice.

3. Buddhist Psychology & Gestalt Therapy Integrated: Psychotherapy for the 21st Century –  Eva Gold and Steve Zahm

For those interested in the intersection between Buddhism and the gestalt technique, this book will be of particular interest.

Gestalt therapy is an exciting and versatile therapy that has evolved over the years. There is a dynamic history behind this therapy, and it should not be discounted by practitioners, coaches, or therapists who are deciding upon their orientation.

Gestalt psychology also has appeal to laypeople who find the gestalt way of life to be in line with their values.

When learning about gestalt therapy, it is essential to maintain a focus on the underlying theory, moving past the charisma of its founder, Fritz Perls. Perls’s work is instructive and vital to understanding the rise of gestalt therapy.

If you are interested in practicing gestalt therapy, take the time to learn the story and the theory, and then make it your own.

We hope you enjoyed reading this article. For more information, don’t forget to download our three Positive CBT Exercises for free .

• Bowman, C. (1998). Definitions of gestalt therapy: Finding common ground. Gestalt Review , 2 (2), 97–107.
• Bowman, C. E. (2005). The history and development of gestalt therapy. In A. L. Woldt & S. M. Toman (Eds.), Gestalt therapy: History, theory, and practice (pp. 3–20). Thousand Oaks, CA: Sage.
• Dolliver, R. H. (1981). Some limitations in Perls’ gestalt therapy. Psychotherapy: Theory, Research & Practice , 18 (1), 38–45.
• Gold, E., & Zahm, S. (2018).  Buddhist psychology and gestalt therapy integrated: Psychotherapy for the 21st century . Metta Press.
• Janov, A. (2005). Grand delusions: Psychotherapies without feeling. Retrieved from http://primaltherapy.com/GrandDelusions/GD12.htm
• Latner, J. (1973). The Gestalt therapy book: A holistic guide to the theory, principles, and techniques of Gestalt therapy developed by Frederick S. Perls and others. New York, NY: Julian Press.
• Leahy, M., & Magerman, M. (2009). Awareness, immediacy, and intimacy: The experience of coaching as heard in the voices of Gestalt coaches and their clients. International Gestalt Journal , 32 (1), 81–144.
• O’Leary, E. (2013). Key concepts of gestalt therapy and processing. In E. O’Leary (Ed.), Gestalt therapy around the world (pp. 15–36). Malden, MA: John Wiley & Sons.
• Paivio, S. C., & Greenberg, L. S. (1995). Resolving “unfinished business”: Efficacy of experiential therapy using empty-chair dialogue. Journal of Consulting and Clinical Psychology , 63 (3), 419–425.
• Perls, F. S. (1969). Gestalt therapy verbatim . Lafayette, CA: Real People Press.
• Perls. F. S., Hefferline, R., & Goodman, P. (1951). Gestalt therapy: Excitement and growth in the human personality . New York, NY: Julian Press.
• Wulf, R. (1996). The historical roots of gestalt therapy. Gestalt Dialogue: Newsletter for the Integrative Gestalt Centre. Christchurch, NZ.

Share this article:

Article feedback

What our readers think.

Thank you for a hugely informative article. Helped me to draw together the different strands of Gestalt in a coherent way.

As a student of counseling, I saw Perls’ video and was totally turned off to the technique. Then I got a practice client who was emotionally shut down and agonized over the various techniques to use that were in my textbook. I realized the client’s mom (the “figure”) was in the room with us and decided to try Gestalt despite my misgivings. It was incredibly fruitful, driving me to always be in the present with the client and always examine my own blocks to being totally present in the moment with the client. I veered into what appeared to be other methodologies as necessary such as somatic, mindfulness, even CBT, but found that those methodologies were actually already part of Gestalt as I learned more about it. It’s a very flexible and powerful container for addressing a client’s needs and keeping the therapist honest with themselves and growing professionally.

I really liked your summary and references, they helped me explain what I’m thinking about Gestalt to others.

How to answer the question “how are you? ” in gestalt

Obviously the client can answer any way they choose, but seeing as Gestalt Therapy focuses on present-moment experience, they might be encouraged to respond openly and honestly with reference to how they presently feel in their body, thoughts running through their head, etc. These are just a couple examples 🙂

Hope that answers your question.

– Nicole | Community Manager

Great and informative article and the video was very helpful in putting this together.

Let us know your thoughts Cancel reply

Your email address will not be published.

Save my name, email, and website in this browser for the next time I comment.

Related articles

How to Integrate Milieu Therapy & Positive Psychology

Milieu therapy and positive psychology offer a unique synergy that has the potential to transform mental health care and create environments that nurture and uplift [...]

Humanistic Therapy: Unlocking Your Clients’ True Potential

Humanism recognizes the need of the individual to achieve meaning, purpose, and actualization in their lives (Rowan, 2016; Block, 2011). Humanistic therapy was born out [...]

Trauma-Informed Therapy Explained (& 9 Techniques)

Trauma varies significantly in its effect on individuals. While some people may quickly recover from an adverse event, others might find their coping abilities profoundly [...]

Read other articles by their category

• Body & Brain (52)
• Coaching & Application (39)
• Compassion (23)
• Counseling (40)
• Emotional Intelligence (22)
• Gratitude (18)
• Grief & Bereavement (18)
• Happiness & SWB (40)
• Meaning & Values (26)
• Meditation (16)
• Mindfulness (40)
• Motivation & Goals (41)
• Optimism & Mindset (29)
• Positive CBT (28)
• Positive Communication (23)
• Positive Education (37)
• Positive Emotions (32)
• Positive Leadership (16)
• Positive Parenting (14)
• Positive Psychology (21)
• Positive Workplace (35)
• Productivity (16)
• Relationships (46)
• Resilience & Coping (39)
• Self Awareness (20)
• Self Esteem (37)
• Strengths & Virtues (29)
• Stress & Burnout Prevention (33)
• Theory & Books (42)
• Therapy Exercises (37)
• Types of Therapy (54)

3 Positive CBT Exercises (PDF)

The place of Gestalt Theory in American psychology A case study

Cite this chapter.

• Abraham S. Luchins  

127 Accesses

4 Citations

Zusammenfassung

Gestalt theory, which arose in and was demonstrated with psychological phenomena, was one of the answers to a crisis in Western intellectual thought which is still with us. There has been, in the 20th century, a growing hostility toward science among the intellectuals, expecially the younger generation, which seems to be caused by the opinion that science offers them nothing when they turn to it for answers to the most fateful questions that confront them, namely, questions about the meaning of human existence. They are not content with the goods and services and with the domination of nature by man that are often pointed to as proof that science leads to the betterment of mankind as well as to the understanding of nature. Science, they say, ignores what human beings encounter in their daily lives. 1) Some implications of Gestalt theory for dealing with the crisis are reflected in a paper written by Max Wertheimer in 1924. It is based on a lecture that Wertheimer gave that year at a meeting of the Kantgesellschaft in Berlin. He spoke from only a few notes and had no manuscript but the speech was taken down in shorthand while he spoke. Due to the urging of people who heard it, the shorthand record of the speech was published with minor changes (1924).

We are indebted to the many psychologists who took time off to answer our questionnaire. We are especially thankful for the help of H. Ansbacher , D.E. Berlyne , J.P. Guilford , E.J. Gibson , J.J. Gibson , D.O. Hebb , R. Held , E.R. Hilgard , L.G. Humphreys , D.M. Johnson , R.W. Leeper , C. Pfaffmann , S. Rosenzweig , R. Stagner , and S.B. Sells . They are not responsible for the errors of accent, ommission, and composition which reflect the writer’s experiential background.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Subscribe and save.

• Get 10 units per month
• Download Article/Chapter or eBook
• 1 Unit = 1 Article or 1 Chapter
• Cancel anytime
• Available as PDF
• Read on any device
• Instant download
• Own it forever
• Compact, lightweight edition
• Dispatched in 3 to 5 business days
• Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Unable to display preview.  Download preview PDF.

Similar content being viewed by others

Gestalt/Gestalt Theory

Gestalt, Equivalency, and Functional Dependency: Kurt Grelling’s Formal Ontology

The World of Psychology Before Relational Frame Theory

You can also search for this author in PubMed   Google Scholar

Editor information

Editors and affiliations.

Institut für Psychologie, Universität Göttingen, Hermann-Föge-Weg 15, D-34, Göttingen, Deutschland

Suitbert Ertel

Psychologisches Institut, Universität Münster, Rosenstr. 9, D-44, Münster i. w., Deutschland

Lilly Kemmler

Psychologisches Institut, Universität Münster, Prinzipalmarkt 36, D-44, Münster i. w., Deutschland

Michael Stadler

Rights and permissions

Reprints and permissions

Copyright information

© 1975 Dr. Dietrich Steinkopff Verlag, Darmstadt

About this chapter

Luchins, A.S. (1975). The place of Gestalt Theory in American psychology A case study. In: Ertel, S., Kemmler, L., Stadler, M. (eds) Gestalttheorie in der Modernen Psychologie. Steinkopff. https://doi.org/10.1007/978-3-642-72312-4_4

Download citation

DOI : https://doi.org/10.1007/978-3-642-72312-4_4

Publisher Name : Steinkopff

Print ISBN : 978-3-7985-0400-4

Online ISBN : 978-3-642-72312-4

eBook Packages : Springer Book Archive

You are here

The Sage website, including online ordering services, may be unavailable due to system maintenance on September 14th between 2:00 am and 8:30 pm BST. If you need assistance, please  visit our Contact us page .

Thank you for your patience and we apologise for the inconvenience.

Gestalt Counselling in Action

• Petruska Clarkson
• Simon Cavicchia - Metanoia Institute
• Description

Simon Cavicchia has oriented Clarkson’s seminal work of Gestalt Counselling in Action within a more contemporary context, adding voices of significant and divergent thinkers as counter-point and extensions of the author’s work. Michael Clemmens, Gestalt Institute of Cleveland, USA

This popular and well written book which is now in its 4 th edition provides an accessible and thorough introduction to the Gestalt approach. Danny Porter, Manchester Gestalt Centre Now 24 years old with over 40,000 copies sold worldwide, Petruska Clarkson’s classic text is the definitive introduction to Gestalt therapy. This fourth edition, updated by Simon Cavicchia, covers the latest in Gestalt theory, research and practice. It includes:

• An extended case study running through the book to help you understand the process of therapy and the techniques used in each of the phases.
• Learning features and case examples translating theory into practice.
• New ‘reflection sections’ showing you the most recent developments in the field.
• New material on the relational turn and research.

As a student of Gestalt therapy, this is the one book you need to buy; it offers a uniquely practical and accessible approach to an often complex topic.

Petruska Clarkson was a professor and fellow of the British Association for Counselling and Fellow of the British Psychological Society. Petruska sadly passed away in 2006 .

Simon Cavicchia is a primary tutor on the MSc in Gestalt Psychotherapy and Joint Programme Leader of the MSc in Coaching Psychology/MA in Psychological Coaching, both at Metanoia Institute, London.

This popular and well written book which is now in its 4 th edition,  provides an accessible and thorough introduction to the Gestalt approach. At the time she wrote this book, Petruska Clarkson brought an extensive experience both as a practitioner and trainer/supervisor to outline the theoretical and philosophical basis of Gestalt therapy. She provides an interesting framework using the cycle of awareness to explore ‘healthy’ and ‘dysfunctional’ functioning of the individual in relation to our environment. The book also outlines the developmental stages of the therapy process and provides a nice balance of theory and practice. I would recommend this as essential reading to anyone with an interest in Gestalt therapy.

An excellent overview of Gestalt Therapy. Up to date, and illustrated with a wealth of case material.

This book is slightly disappointing. The theory might be useful, to students who are studying Gestalt, but what our students would probably need from such a book would be more on the actual practice.

Students found this accessible and it suopports their understanding of gestalt methods and principles

Clearly written and appropriate to readers

Clarkson gives a good basic understanding of Gestalt principles and practice.

Excellent, practical book which enables the students to move through application of the practical skills. I have recommended this book to a colleague who teaches basic counselling skills as i think the book will benefit all students on that course. I have suggested students refer to it in Learning Disability and Mental Health practice also.

This book is excellent for either a quick reference book or for more in depth reading for Gestalt therapy would recommend this book for learners level 3 and above

A good updating of one of the original gestalt texts which focusses on tracking clinical issues through the concept of the cycle of experience.

This text provides a clear introduction to some of the important concepts within gestalt counselling. I am going to include on our recommended list for a module on therapeutic models. This will enhance students' awareness of alternative therapies and provide invaluable information for preparing academic assignments.

Preview this book

Sample materials & chapters.

Ch.2: Fundamentals of the Gestalt Approach to Counselling

For instructors

Please select a format:

Select a Purchasing Option

• Electronic Order Options VitalSource Amazon Kindle Google Play eBooks.com Kobo

Related Products

• Bipolar Disorder
• Therapy Center
• When To See a Therapist
• Types of Therapy
• Best Online Therapy
• Best Couples Therapy
• Managing Stress
• Sleep and Dreaming
• Understanding Emotions
• Self-Improvement
• Healthy Relationships
• Student Resources
• Personality Types
• Sweepstakes
• Guided Meditations
• Verywell Mind Insights
• 2024 Verywell Mind 25
• Mental Health in the Classroom
• Editorial Process
• Meet Our Review Board
• Crisis Support

How Gestalt Therapy Works

Getty Images

What Are the Pillars of Gestalt Therapy?

What is an example of gestalt therapy, what is the main goal of gestalt therapy, effectiveness, things to consider, why is gestalt therapy controversial, how to get started.

Gestalt therapy is a form of psychotherapy that focuses on a person's present life rather than delving into their past experiences. This form of therapy stresses the importance of understanding the context of a person’s life when considering the challenges they face. It also involves taking responsibility rather than placing blame.

Gestalt, by definition, refers to the form or shape of something and suggests that the whole is greater than the sum of its parts. There is an emphasis on perception in this particular theory of counseling. Gestalt therapy gives attention to how we place meaning and make sense of our world and our experiences.

Gestalt therapy was developed by Fritz Perls, with the help of his wife at the time, Laura Perls, and introduced in the 1940s as an alternative to more traditional psychoanalysis . Both Fritz and Laura were trained in psychoanalysis and gestalt psychology.

Along with others, such as Paul Goodman, they worked together to develop a style of therapy that was humanistic in nature. In other words, the approach focused on the person and the uniqueness of their experience.

Get Help Now

We've tried, tested, and written unbiased reviews of the best online therapy programs including Talkspace, BetterHelp, and ReGain. Find out which option is the best for you.

There are a number of principle ideas that come into play with gestalt therapy, from perception to self-awareness .

Experience Influences Perception

In this  client-centered  approach to therapy, the gestalt therapist understands that no one can be fully objective and that we are influenced by our environment and our experiences. A therapist trained in gestalt therapy holds space for their clients to share their truth, not imposing their judgment and accepting the truth of their clients' experiences.

Since therapists are human as well, it is important for gestalt therapists to consider the influence of their own experiences on what is happening in the session.

Context Matters

When in session, gestalt therapists want to learn about the experience of their clients. It is understood that context matters and the therapists use techniques to help the client become more aware of their experiences, their perceptions, and their responses to events in the here and now.

Rather than specifically targeting the past and asking clients to purposefully bring up old experiences, gestalt therapists operate from a place of understanding that as clients become increasingly aware, they will overcome existing roadblocks. There is no forced work or technique, just holding space for client awareness is key in this approach.

The Present

The main hallmark of gestalt therapy is the focus on the present. In the session, the client and therapist rapport is critical in building trust and safety. As the client shares, a gestalt therapist will help bring the client back to the present if there is a sense they are spending too much time in the past or if their  anxiety  may be speeding them into the future.

An example of keeping a client present in gestalt therapy might include something like asking the client about their facial expression or body language as they process a particular event or experience. In asking about something they are observing in the room, they are helping the client come back to the present and process what is happening for them at that moment.

Working Through Pain

We work very hard to survive painful experiences, and part of this survival may include shutting down our emotional hurt or painful memory of the event. In gestalt therapy, you are offered a space where you don't have to do that hard work anymore.

This isn't to suggest that things will come up quickly, but they don't have to. A gestalt therapist understands that things such as painful memories or events will come to awareness when the client is ready for healing in that area.

Self-Awareness

During gestalt therapy, there may be some experiential exercises that you will do with your therapist. Experiential exercise refers to therapeutic activities done in therapy that can help to  increase awareness  and help with processing. At the heart of gestalt therapy is awareness. As Frederick Salomon Perls put it, "Awareness in itself is healing."

Rather than sitting still and talking, you may be asked to actively participate in something like role play, guided imagery , or the use of props to help communication and understanding. Engaging in experiential exercises can be a wonderful way to open up and share, especially when it is difficult to find words or when you tend to process in a more visual way. Gestalt therapists understand that these exercises help to increase awareness.

Some therapy approaches tend to focus on the therapist as an expert on distress and symptoms. The client has more of a learning role, as the therapist shares their knowledge about what they are experiencing and how to heal.

Within gestalt therapy, the client has space to safely explore their experiences without fear of judgment. In fact, the client is encouraged to not simply talk about their emotions or experiences, but to bring them into the room so they can be processed in real-time with the therapist.

The therapist may guide you using several techniques.

The goal of gestalt therapy is for the client to collaborate with the therapist to increase personal awareness and actively challenge the roadblocks that have been getting in the way of healing.

Words and Language

Attention to language and tone is important in gestalt therapy. As clients learn to accept responsibility, they learn to use language that reflects a sense of personal ownership rather than focusing on others. For example, rather than saying, "If he didn't do that I wouldn't get so mad!" a client might be encouraged to say, "I feel mad when he does that because it makes me feel insignificant and I don't like that."

The use of "I" statements is important in gestalt therapy.

Empty Chair

This is a role-playing exercise that allows a client to imagine and participate in a conversation with another person or another part of themselves. Sitting across from the empty chair, the client enters into a dialogue as if they were speaking with that other person or that other part of themselves.

The empty chair exercise can be very helpful in drawing out important perceptions, meanings, and other information that can help clients become more aware of their emotional experience and how to start healing.

Another example of role-playing might be what is referred to as "top dog and underdog." In this, it is recognized that a client has different parts of self. Similar to the empty chair, the client speaks as both the top dog, which is the more demanding side of their personality and the underdog, which is the more submissive and obedient side of their personality.

The key is to become aware of inner conflicts so that the person can better learn how to integrate these parts of self into a more complete whole.

Body Language

During a session, a gestalt therapist will observe the client's body language and movement such as tapping their foot, wringing their hands, or making a certain facial expression. The therapist is likely to mention their observation of this and ask what is happening for the person at that moment.

Incorporating language, the gestalt therapist may even ask the client to give their foot, hands, or facial expression a voice and speak from that place.

Exaggeration

In addition to giving body language a voice, a gestalt therapist may inquire about the client's body language. If it is difficult for the client to find words to put to what is happening, they may be asked to exaggerate that motion or repeat it several times in a row for a period of time during the session to draw out some of their experience at that moment.

The client and the therapist get a chance to process emotions and how the person might have learned to disconnect their emotional experiences with their physical experiences.

Locating Emotion

During a session, it is common for people to talk about emotion. Talking about emotion is different than experiencing an emotion. As a client talks about emotion, the therapist may ask them where they feel that emotion in their body.

Examples of how a person might describe how they're experiencing emotion in their body include "a pit in my stomach" or "my chest feels tight." Being able to bring the emotional experience to awareness in the body helps the client stay present and process their emotions more effectively.

Creative Arts

Additional activities such as painting, sculpting, and drawing can also be used to help people gain awareness, stay present, and learn how to process the moment. It is generally noted in this style that any technique that can be offered to the client, other than traditional sitting still and talking, can be helpful in allowing them to become more aware of themselves, their experiences, and their process of healing.

What Gestalt Therapy Can Help With

There are a variety of conditions that gestalt therapy may be used to treat, including:

• Low self-efficacy
• Low self-esteem
• Relationship problems

Benefits of Gestalt Therapy

Some of the potential benefits of gestalt therapy include:

• An improved sense of self-control
• Better ability to monitor and regulate mental states
• Better awareness of your needs
• Better tolerance for negative emotions
• Improved communication skills
• Improved mindfulness
• Increased emotional understanding

Staying Present

Gestalt therapy aims for the client to gain greater awareness of their experience of being in the world. Gestalt therapists do not have a goal of changing their clients. In fact, clients are encouraged to focus on becoming more aware of themselves, staying present, and processing things in the here and now.

The collaborative relationship between therapist and client is fundamental to the healing process in gestalt therapy.

Self-Awareness and Growth

It is suggested that the way we learn how to survive experiences, particularly painful experiences, is to create blocks or push things out of awareness so that we can move forward. As effective as it may seem, it can create trouble for us as we become more compartmentalized and fragmented in our sense of self and our experiences.

The very techniques we once used to help ourselves become blocks to self-awareness and growth. Increasing client awareness allows for these blocks to be identified, properly challenged, and moved out of the way so we can find healing and personal growth.

Personal Responsibility

A key goal in gestalt therapy is to give clients the opportunity to own and accept their experiences. In blaming others, we lose our sense of control and become victims of the event or the others involved in the event. Gestalt therapy encourages clients to challenge those old ways of how we may have created meaning about an experience.

Learning how to accept and embrace personal responsibility is a goal of gestalt therapy, allowing clients to gain a greater sense of control in their experiences and to learn how to better regulate their emotions and interactions with the world.

Self-Regulation and Growth

Gestalt therapy suggests that people strive for self-regulation and growth but that they sometimes develop maladaptive techniques to survive painful experiences. Some of these techniques feel helpful in the short term because they can help minimize our pain or distress.

However, over the long term, they leave us in more emotionally shaky places, unable to express ourselves. We may find it hard to interact with others, and difficult to learn how to effectively regulate ourselves and be whole, responsible beings.

Gestalt therapy believes that, despite some of these setbacks, people are still wired for this sense of wholeness and feel distressed when we are not able to achieve it. Our distress might look like physical illness, emotional reactivity, isolation, and more.

Research suggests that gestalt therapy can be effective for treating a variety of conditions including anxiety and personality disorders and is at least as effective as other psychotherapy approaches.

• One study on people with anxiety in Hong Kong found that four weeks of gestalt therapy resulted in lower levels of anxiety, less avoidance of inner experience, and more mindfulness and kindness toward oneself. Self-judgment was not influenced, however.
• Several studies have tested gestalt therapy in women with depression and found the treatment to be as effective as cognitive therapy and more effective than drug therapy in treating symptoms of depression.
• A study on divorced women found that 12 sessions of gestalt therapy improved the women's self-efficacy, or ability to cope.
• One study on individuals with bipolar disorder found gestalt therapy to be an effective outpatient treatment for not only improving symptoms of the disorder but helping individuals to improve in their social, work, and school lives.

Gestalt therapy has both some pluses and minuses. Two potential weaknesses of gestalt therapy are that it requires a therapist to have a high degree of personal development and knowledge and it only focuses on the present. Therapists who don't have a deep understanding of the theory behind gestalt therapy may be tempted to utilize its techniques and exercises haphazardly, which isn't likely to serve the client's needs.

For some people, the focus on the present can feel limiting. Although revisiting the past is an important part of identifying what needs to be healed, gestalt therapy is an approach that focuses more on the "here and now" experience of the client. Additionally, depending on how the exercises are approached, the concentration on body language and emotions can leave some people feeling uncomfortable, vulnerable, and defensive rather than safe and supported.

If you think you or someone you love would benefit from gestalt therapy, consider the following steps:

• Get a recommendation . Ask your primary care doctor or mental health professional to refer you to a therapist certified in gestalt therapy.
• Inquire about cost . If gestalt therapy is not covered by your health insurance, ask the potential therapist about their fees per session and whether they offer a sliding scale, or pricing based on a person's income.
• Be prepared to answer questions about the present moment . Expect the therapist to ask you about your experience in the present moment. For example, your therapist may start the session by asking: "What are you aware of right now?"

Leung GSM, Khor SH. Gestalt intervention groups for anxious parents in Hong Kong: A quasi-experimental design . J Evid Inf Soc Work . 2017;14(3):183-200. doi:10.1080/23761407.2017.1311814

Brownell, P. (2016). Contemporary Gestalt therapy . In D. J. Cain, K. Keenan, & S. Rubin (Eds.), Humanistic psychotherapies: Handbook of research and practice (p. 219–250). American Psychological Association. doi:10.1037/14775-008

Heidari S, Shahbakhsh B, Janjoo M. The effectiveness of Gestalt therapy on depressed women in comparison with the drug therapy . Journal of Applied Psychology & Behavioral Science . 2017;2(1):14-18.

Saadati H, Lashani L. Effectiveness of gestalt therapy on self-efficacy of divorced women .  Procedia - Social and Behavioral Sciences . 2013;84:1171-1174. doi:10.1016/j.sbspro.2013.06.721

Knez R, Gudelj L, Sveško-Visentin H. Scientific letter: gestalt psychotherapy in the outpatient treatment of borderline personality disorder: A case report .  Afr J Psych . 2013;16(1):52-53. doi:10.4314/ajpsy.v16i1.9

Gestalttheroy.com. 2016. Gestalt therapy .

Wagner-Moore, L.E. 2004. Gestalt therapy: Past, present, theory and research .

By Jodi Clarke, MA, LPC/MHSP Jodi Clarke, LPC/MHSP is a Licensed Professional Counselor in private practice. She specializes in relationships, anxiety, trauma and grief.

Gestalt Therapy and Post-Traumatic Stress Disorder: The Irony and the Challenge

• January 2003
• Gestalt Review 7(1):42

• Israeli Academic College

Discover the world's research

• 25+ million members
• 160+ million publication pages
• 2.3+ billion citations

• John M. Laux
• Ph.D. Sarah M. Toman

• Patrick Fontan
• Chris Piotrowski

• Enil Afşaroğlu Eren
• Olga O. Andronnikova
• A. V. Vasileva

• M.A. Dorian Kondas
• Malcolm Parlett
• Petrüska Clarkson
• Jennifer Mackewn
• VIOLET OAKLANDER
• J Cognit Psychother
• Robert L. Leahy
• Stephen J. Holland
• Andrew C. Butler
• Elizabeth M. Ellis
• L. S. Greenberg

• Allen Frances

• Laura N. Rice
• Joseph Zinker
• Recruit researchers
• Join for free
• Login Email Tip: Most researchers use their institutional email address as their ResearchGate login Password Forgot password? Keep me logged in Log in or Continue with Google Welcome back! Please log in. Email · Hint Tip: Most researchers use their institutional email address as their ResearchGate login Password Forgot password? Keep me logged in Log in or Continue with Google No account? Sign up

The Four Pillars of Gestalt Therapy

Practitioners of gestalt therapy – developed by Laura and Friedrich (‘Fritz’) Perls in the 1940s and 1950s, and defined as ‘a distinctive method of counselling and therapy … which emphasises immediacy, experiencing and personal responsibility’ (Feltham and Dryden, 1993: 75) – are guided by four theoretical pillars:

• phenomenology
• dialogical relationship
• field theory
• experimentation

Used holistically within therapy, these four pillars are interrelated and support each other.

Phenomenology

Gestalt therapy focuses on the here and now, that is the immediate experience of the client. While the past certainly affects how we perceive the world, the gestalt therapist wants to understand what is happening for the client in the moment. Thus, the therapist asks the client to describe their feelings rather than trying to analyse or interpreting.  This method is known as ‘phenomenology’; it heightens awareness and relational depth.

Originating in philosophy, phenomenology – ‘an approach to psychology (and other sciences) based on the study of immediate experience’ (Tudor & Merry, 2006: 107) –recognises that to each individual, their own experience holds far greater authority than anything else. As well as gestalt therapy, phenomenology also underpins transactional analysis and person-centred counselling .

The basic ideas underlying phenomenology can be traced back to the Greek philosopher Plato, though the specific historical movement was developed in the first half of the 20th century by philosophers and thinkers such as:

• Edmund Husserl
• Martin Heidegger
• Maurice Merleau-Ponty
• Jean-Paul Sartre.

Dialogical Relationship

The therapeutic relationship needs a working alliance and a dialogic relationship. In Gestalt, the dialogical relationship is where the therapist is required to bring their whole self to the relational contact with the client. The counsellor must be fully present, understanding, validating and authentic. In so doing, they provide presence, confirmation, inclusion and open communication. The dialogical relationship requires the therapist to pay attention not only to their moment-to-moment contact with the client but also to their own internal process, being as authentic, attentive and present as possible.

Yontef and Jacobs (2005: 320) write:

Dialogue is the basis of the gestalt therapy relationship. In dialogue, the therapist practices inclusion, empathic engagement, and personal presence, e.g. self-disclosure. In the process of doing this, the therapist confirms the existence and potential of the patient, the therapist imagines the reality of the patient’s experience and in doing so confirms existence of the patient.

Field Theory

Field theory investigates interaction patterns between individual people and the ‘field’, i.e. the environment. Tudor and Merry (2006: 56) define ‘field theory’ as ‘the view, developed by Lewin (1952) and taken up particularly by gestalt therapy, that psychological relationships may – and indeed, can only – be studied and understood in terms of their surrounding “field”’.

Field theory underpins the holistic view of the client. There are three types of field:  experiential field, relational field and wider field, which are interconnected. The field will be in constant flux so the counsellor needs to keep a flexible focus on what is figural, as well as shuttling between the three fields, to understand how the client is making meaning of the experiences.

Experimentation

Gestalt therapy explores the person not only through what they say but also through how they act. People communicate in many ways, not just verbally; often much of this communication is unconscious. Gestalt experiments offer clients the chance to become involved in action-based exercises that heighten their awareness as they make contact with their environment. For example, the therapist may comment on repetitive physical patterns, facilitating the client to examine these and to decide whether or not they are helpful.

Because of its focus on action as well as talk, gestalt therapy is considered an experiential approach. Clients have the opportunity, through experiments, to try out new behaviours – first in the safety of the therapeutic relationship (even just through talking about them) and then (where appropriate) in the outside world. This can help clients to express themselves behaviourally.

Free Handout Download

Four Pillars of Gestalt Therapy

Feltham C and Dryden W (1993) Dictionary of Counselling , Whurr Publishers

Lewin (1952) Field Theory in Social Science , Harper & Rowe

Tudor K and Merry T (2006) Dictionary of Person-Centred Psychology , PCCS Books

Yontef G and Jacobs L (2005) ‘Gestalt Therapy’ in Corsini R and Wedding D, Current Psychotherapies , Thomson Brookes/Cole

• Mental Health Academy

• Case Studies
• Communication Skills
• Counselling Microskills
• Counselling Process
• Children & Families
• Ethical Issues
• Sexuality & Gender Issues
• Neuropsychology
• Practice Management
• Relationship Counselling
• Social Support
• Therapies & Approaches
• Workplace Issues
• Anxiety & Depression
• Personality Disorders
• Self-Harming & Suicide
• Effectiveness Skills
• Stress & Burnout
• Diploma of Counselling
• Diploma of Financial Counselling
• Diploma of Community Services (Case Management)
• Diploma of Youth Work
• Bachelor of Counselling
• Bachelor of Human Services
• Master of Counselling

A Case for Gestalt Therapy

Author: Jane Barry

Komiko is from a second-generation Asian family. She has lived in Australia all her life, yet her Asian roots are deep. She has been raised according to traditional Asian culture and in addition, she and her family are devout Catholics. Komiko has never questioned her upbringing before, yet now at the age of 26 she is struggling with value conflicts relating to her religion, culture and sex-role expectations and has come to counselling in order to allay some of her confusion.

A précis of the sessions is as follows. For ease of writing the Professional Counsellor is abbreviated to “C”.

Background Information

Komiko had a strict and formal upbringing with her parents and the various Catholic schools that she attended. She was taught to always honour and respect her elders, such as her parents, teachers and priests. Because of this she explains that she has never really felt independent of figures of authority, and has usually acted out the role of a willing child. She states that she seeks the approval of those in authority and whenever she attempts to assert her own will, she experiences guilt and self-doubt.

She has always followed closely the rules and morals of the Catholic Church, through her school and adult life. Komiko has never been married, nor has she had a long-term relationship or experienced sexual intimacy. She states that this is primarily because of the codes she has learned to live by, however there have been times when she has wanted to break away from these. She is interested in living away from her parents and experiencing a relationship out of wedlock, however she is afraid that if she does so, her parents will not accept her decisions.

Although Komiko is frightened to break away from the codes and rules that she has learned, she is seriously considering their validity and realism. She has noticed a change in her own beliefs about morality, and how she no longer accepts her family’s and church’s beliefs without question. She wonders about the importance of her own individual conscience, and following her changing beliefs. The questions she asks herself include: What if I am wrong? Who am I to decide what is moral or immoral? What will I discover if I follow my own path? Will I lose my self-respect or be able to survive the guilt I feel if I don’t follow the teachings of my church and parents?

Generally, Komiko would like to be less dependent, less socially inhibited, less emotionally reserved and be more assertive and able to make important decisions in her life. Instead she finds that she is extremely self-conscious and always considers how she should and should not act. She wonders if she has the strength to act in opposition to what she has learned from her culture, her parents and her church.

Session Content

After drawing out Komiko’s story and beliefs, “C” considers some of the core issues that she is facing. “C” summarises the nature of Komiko’s struggle as follows:

Child roles vs Adult roles:

• Catholic morals vs non-Catholic morals
• Asian influences vs Western influences

Whilst listening to Komiko, “C” considers briefly her own opinions about these conflicts. “C” is a Western, non-Catholic woman and realises her own biases in these arguments may lead her to influence Komiko away from traditional, Asian and Catholic codes of living. “C” also considers that Komiko may be looking to “C” as someone in authority to grant her permission to act more in accordance with her own views.

“C” started with a warm up exercise with Komiko. “C” asked Komiko to summarise the way she was feeling about herself. Komiko stated that she felt self-conscious, weak willed, lacking in assertiveness and dependent. “C” discussed these opinions further with Komiko and asked her questions such as “How are you dependent? Who is responsible for your self-consciousness? What do you take responsibility for?”

Komiko became aware of her passivity through this exercise, and her tendency to allow others to dictate how she should live. “C” then asked Komiko to use the “I take responsibility for.” exercise where she repeated out-loud, all of the current feelings that she was responsible for. “C” then encouraged Komiko to take responsibility for the goals she wanted to achieve.

Komiko said:

• I am responsible for my self-consciousness.
• I am responsible for my dependency.
• I am responsible for my independence.
• I am responsible for my decision making.

“C” added some responsibilities of her own:

• I am responsible for helping you explore your blockages.
• I am responsible for allowing you to make your own choices.
• I will not take responsibility for your decision making.

This exercise allowed “C” and Komiko to examine their roles in the counselling relationship and reinforced that Komiko was responsible for the decision making. Komiko and “C” both were fairly warmed up after this exercise, so “C” encouraged Komiko to perform a dialogue exercise between her assertive self and her unassertive self. “C” explained that this was a chance for both of these sides to talk to each other and air their grievances.

“C” said to Komiko, “In this first chair I want you to position yourself as your assertive self. Your assertive self should talk to your unassertive self in this other chair. “As your assertive self, I want you to sit, speak and act in an assertive manner. You should tell your unassertive side what it is you want to be more assertive about and why.”

As Komiko progressed through this exercise, “C” prompted her to talk about what her assertive side felt and to point out what she didn’t like about her unassertive self. Komiko grew slowly into her role as her assertive self. She experimented with the role of advice giver and decision maker, clarifying the choices that she wanted to make in regards to her life. In particular these included moving out of her parental home and pursuing a relationship.

After this point, Komiko was a little quiet. When prompted to speak, Komiko explained that she feared her parent’s response to these changes. “C” then suggested that Komiko take on her unassertive side. Komiko’s unassertive side defended some of the actions and principles of her traditional upbringing. She explained some of the value that she saw in behaving in accordance with the belief’s of her parents. She wanted to make her own choices, but she wanted her parent’s approval to do so. She was afraid that they would not tolerate her decisions. She explained that some of her parent’s expectations included having supervised dates with young men, living at home until she was married, preferably marrying a Japanese man, wearing skirts and dresses and generally keeping a feminine appearance.

After lengthy discussions with her two sides, Komiko came to realise more clearly the nature of her conflict. Her assertive side wanted to move out of home and be more independent, realising that she may have to live with the disapproval of her parents for a while. Komiko’s unassertive side felt afraid without the support of her family. She thought that maybe she could ease her parents into the idea of her moving out by starting to collect furniture, saving money, looking for suitable apartments and discussing her plans with them.

“C” suggested to Komiko to consider the consequences of moving out on her own, or staying in her parents house. “C” also suggested to Komiko to write a letter to her parents, to tell them of her fears of their disapproval and the consequences this has for her. “C” explained to Komiko that the letter should not be sent, but that she could bring the letter to their next session to discuss its meaning.

In the final part of the session, “C” asked Komiko how she might feel about attempting a more difficult exercise – playing the role of her non-Catholic self, non-traditional self. “C” explained that Komiko was already well acquainted with her Catholic/traditional self and suggested that she experience what it would be like to be her non-Catholic, non-traditional self.

Initially Komiko was hesitant and didn’t understand how she might act as a non-Catholic or non-traditional self. “C” suggested that she think about how she might look, what she might wear, how she might do her hair. Komiko thought that she might wear pants more often, dress in a less feminine style and cut her hair shorter. She practiced walking around the room, as this side of herself, slowly gaining confidence to put a bounce in her step and imagining her hair to be shorter and coloured. She was quite shy about her performance and so “C” joined in also, by mimicking her movements and asking her to describe how she felt about herself.

When seated again, “C” moved on to ask Komiko how she might act on an average day. “C” asked her to imagine her non-Catholic, non-traditional self going to work, doing the shopping or visiting friends. Komiko imagined herself talking avidly to her more assertive friends about making decisions. She discussed the possibility of having her own place to be herself, and how she might plan meals for herself and arrange everything to her own liking. She thought of having friends stay over for weekends and setting up a study room for her work.

Komiko moved on to consider having the freedom to see a male friend from church that she was interested in, without being under the watch of her parents. After this point she was quiet and “C” asked what she was thinking. Komiko said that her Catholic/traditional side was not happy about this, as she was afraid of becoming involved with someone.

“C” prompted Komiko to imagine how her non-Catholic, non-traditional self might approach this problem. Komiko thought that her non-Catholic self probably wouldn’t get involved unless she thought that the relationship could be serious. When asked what being serious meant, Komiko replied that there would be some sort of verbal agreement with her partner and that she would feel in love. She thought that she might see him on weekends and would consider introducing him to her parents.

“C” asked her how her non-Catholic, non-traditional side would feel at this stage. Komiko thought that she might be quite happy, though her Catholic/traditional side feared that her parents might find out earlier, or might not approve of her choice. As the session was near to finishing, “C” asked Komiko to stop playing the role, suggesting that they may work further on these roles in the next session. Komiko sat quietly for some time, reflecting on her role reversal. “C” expressed her admiration of Komiko’s attempts to explore herself and her conflicts. “C” asked her to give herself some feedback on the session.

Komiko felt that she had further explored her motives for change and her fears of change in further detail. She had come to realise her responsibility for both her assertion and lack of it, and had been surprised at the extent of her desire to take more control of her life. She felt that her assertive side had the strength to be independent, whereas earlier, she didn’t think that she had any inner resources to make changes to her life. She hoped to continue the therapy until she became more decided about the decisions she wanted to make.

“C” validated this progress that Komiko had made and suggested that they might continue the next session by exploring some more of the conflict between her catholic/traditional and non-catholic, non-traditional values and to consider the letter that she was to write to her parents.

End of Session

Some points to consider with Gestalt Therapy include:

The assumption of Gestalt therapy is that individuals are responsible for their own growth and behaviour. It is an experiential approach, designed to help people gain more awareness of what they are doing. Gestalt therapy is an active therapy and clients are expected to take part in their own growth.

Most of the techniques of Gestalt therapy are designed to assist people to more fully experience themselves. The therapist should not force clients to partake in experiments if they don’t want to, but in this instance should explore the client’s resistance to the therapy.

Some of the activities and exercises employed by Gestalt therapists include the following:

• I take responsibility for.this is to help someone accept their own personal responsibility for their feelings, actions and their subsequent consequences. This can be useful if the client is blaming others for their problems. By taking responsibility for their problems, the client may be more empowered to change their thinking, actions, and feelings.
• The dialogue exercise…this is a useful experiment to employ if the person is engaged in a struggle of some kind. The client should carry on a conversation between the two parts of themselves that are in conflict. This exercise can help the client to better understand the motives of each side and clarify their experiences.
• I have a secret…this is a technique for exploring secrets and imagining revealing them to others. It allows the client to think about the reactions of others to their secrets and understand the reasons for keeping these secrets. Writing a letter to someone (but not sending it!) may be a way to explore secrets or taboo subjects.
• Reversal technique…if a client is attempting to deny a side of themselves, this technique may be used to help explore the side they wish to cover up. By experiencing themselves as this side, may help them to explore what they are failing to deal with.
• The Rehearsal technique…we rehearse many things inwardly, when we imagine how situations will be. The technique is to rehearse these out-loud by acting out all the things that you might be experiencing inwardly. You might do this when facing something you are afraid of, such as applying for a job, or asking someone for a date.
• The exaggeration exercise…this is designed to draw attention to our body language. The client is to deliberately exaggerate a body movement that they do often, such as frowning or smiling when they feel hurt. The exercise aims to make people more aware of their feelings when they use these particular body movements and gestures.

These are just some of the experiments used in Gestalt therapy. You may know of others. Perhaps you might like to think about how you might use these experiments with someone like Komiko.

Leave a Reply

You must be logged in to post a comment.

Subscribe to our newsletter

You’ll regularly receive powerful strategies for personal development, tips to improve the growth of your counselling practice, the latest industry news, and much more.

Keyword search

AIPC specialises in providing high quality counselling and community services courses, with a particular focus on highly supported external education. AIPC is the largest provider of counselling courses in the Australia, with over 27 years specialist experience.

Learn more: www.aipc.net.au

Recent Posts

• Men and Emotions: From Repression to Expression
• Men, Emotions and Alexithymia
• The Fine Art of Compassion
• The Benefits of Intentional Daydreaming
• Solution-focused Techniques in Counselling

Gestalt psychology

Our editors will review what you’ve submitted and determine whether to revise the article.

• Frontiers - Gestalt Theory Rearranged: Back to Wertheimer
• Gestalt Institute of Cleveland - What is Gestalt?
• Verywell Mind - What is Gestalt Psychology?
• Social Sciences LibreTexts - Gestalt Psychology
• Academia - Gestalt psychology
• Open Text WSU - The Gestalt Principles of Perception
• BCcampus Open Publishing - Gestalt Psychology: History and Modern-Day Practices
• Simply Psychology - What is Gestalt Psychology?

Gestalt psychology , school of psychology founded in the 20th century that provided the foundation for the modern study of perception . Gestalt theory emphasizes that the whole of anything is greater than its parts. That is, the attributes of the whole are not deducible from analysis of the parts in isolation. The word Gestalt is used in modern German to mean the way a thing has been “placed,” or “put together.” There is no exact equivalent in English. “Form” and “shape” are the usual translations; in psychology the word is often interpreted as “pattern” or “configuration.”

Gestalt theory originated in Austria and Germany as a reaction against the associationist and structural schools’ atomistic orientation (an approach which fragmented experience into distinct and unrelated elements). Gestalt studies made use instead of phenomenology . This method, with a tradition going back to Johann Wolfgang von Goethe , involves nothing more than the description of direct psychological experience, with no restrictions on what is permissible in the description. Gestalt psychology was in part an attempt to add a humanistic dimension to what was considered a sterile approach to the scientific study of mental life. Gestalt psychology further sought to encompass the qualities of form, meaning, and value that prevailing psychologists had either ignored or presumed to fall outside the boundaries of science .

The publication of Czech-born psychologist Max Wertheimer ’s “Experimentelle Studien über das Sehen von Bewegung” (“Experimental Studies of the Perception of Movement”) in 1912 marks the founding of the Gestalt school. In it Wertheimer reported the result of a study on apparent movement conducted in Frankfurt am Main , Germany, with psychologists Wolfgang Köhler and Kurt Koffka . Together, these three formed the core of the Gestalt school for the next few decades. (By the mid-1930s all had become professors in the United States.)

The earliest Gestalt work concerned perception , with particular emphasis on visual perceptual organization as explained by the phenomenon of illusion . In 1912 Wertheimer discovered the phi phenomenon , an optical illusion in which stationary objects shown in rapid succession, transcending the threshold at which they can be perceived separately, appear to move. The explanation of this phenomenon—also known as persistence of vision and experienced when viewing motion pictures —provided strong support for Gestalt principles.

Under the old assumption that sensations of perceptual experience stand in one-to-one relation to physical stimuli , the effect of the phi phenomenon was apparently inexplicable. However, Wertheimer understood that the perceived motion is an emergent experience, not present in the stimuli in isolation but dependent upon the relational characteristics of the stimuli. As the motion is perceived, the observer’s nervous system and experience do not passively register the physical input in a piecemeal way. Rather, the neural organization as well as the perceptual experience springs immediately into existence as an entire field with differentiated parts. In later writings this principle was stated as the law of Prägnanz , meaning that the neural and perceptual organization of any set of stimuli will form as good a Gestalt, or whole, as the prevailing conditions will allow.

Major elaborations of the new formulation occurred within the next decades. Wertheimer, Köhler, Koffka, and their students extended the Gestalt approach to problems in other areas of perception, problem solving , learning , and thinking . The Gestalt principles were later applied to motivation, social psychology , and personality (particularly by Kurt Lewin ) and to aesthetics and economic behaviour. Wertheimer demonstrated that Gestalt concepts could also be used to shed light on problems in ethics , political behaviour, and the nature of truth. Gestalt psychology’s traditions continued in the perceptual investigations undertaken by Rudolf Arnheim and Hans Wallach in the United States .