A century of Gestalt psychology in visual perception: I. Perceptual grouping and figure-ground organization

Abstract

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 is the focus of a second review article.

Figure 1

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

Figure 2

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

Figure 3

Two dimotif rectangular dot lattices with $\frac{\left|\mathrm{b}\right|}{\left|\mathrm{a}\right|}=1.2$.

Figure 4

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.)

Figure 5

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

Figure 6

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.

Figure 7

A motion lattice. and are dot lattices presented in alternation.

Figure 8

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

Figure 9

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 m₁, m₂, and m₃ 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: m₁ in Panel C and m₃ in Panel D. (The stimuli were designed so that m₂ would never dominate.) Adapted from Gepshtein and Kubovy (2007), with permission.

Figure 10

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

Figure 11

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

Figure 12

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).

Figure 13

(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.

Figure 14

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.

Figure 15

(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.

Figure 16

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.

Figure 17

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.

Figure 18

(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.

Figure 19

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.

Figure 20

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).

Figure 21

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

Figure 22

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.

Figure 23

(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).

Figure 24

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.