Perceptual organization and neural computation

Our present understanding of perceptual organization has its roots in the observations and qualitative principles of the Gestalt psychologists. Gestaltists and their associates identified and classified phenomena that reflect how perceptual systems derive representations of the environment based on fragmentary information and stimulus context. A broad range of phenomena was explored in this early work. The perceptual organization of visual motion was a major focus, involving both simple (Korte, 1915; Ternus, 1926; von Schiller, 1933; Wertheimer, 1912) and complex (Duncker, 1929; Musatti, 1924; Rubin, 1927; Wallach, 1935) motion patterns. The perceptual organization of static form was explored in studies of part-whole relationships in simple planar figures (Rubin, 1915; Wertheimer, 1923), and later in studies of illusory contours and amodal completion (Kanizsa, 1955; Michotte, 1964). Additional topics included lightness and color phenomena (Benary, 1924; Gelb, 1929; Katz, 1935; Wallach, 1948), and the perception of events (Michotte, 1941). In brief, the research areas addressed by the first generations of Gestalt psychologists spanned much of what is now vision science. The broad impact of Gestalt ideas is reflected in the exceptional scope of this special issue. This early work provides a rich source of observations and intuitions about mechanisms underlying various aspects of perceptual organization. Building on this foundation, current work is revolutionizing our understanding of perceptual organization in two major respects. First, the qualitative observations and descriptions generated by early work are now replaced by rigorous computational theories. This advance can be traced through a