Perceptual Organization: Vision

Perceptual organization is part of the process by which sensory data collected by our receptors is combined and integrated into structured, organized percepts. The eyes signal information about the light around us, but humans do not consciously experience these separate pieces of information—we don't see countless patches of color from the wavelengths registered by our cones. Instead, we see whole objects and surfaces smoothly integrated into scenes. These wholes are the products of perceptual organization. Sometimes these integrations contain surprises, where the whole pattern may be strikingly different from the sum of its parts: an artist draws a few curves on the canvas and a face emerges; or a set of black dots comprising a newspaper photograph combine into a rich scene; or three black disks with wedged-shaped notches yield the perception of a white triangle (see Perceptual Segregation, Figure 2). Such novel wholes are called gestalts. This entry reviews what perceptual organization does, how it does it, and its practical implications.

A common view sees visual perception beginning with the registration and transduction of light within the retina into neural signals, a process that takes place without our conscious awareness. This is followed by the organization and interpretation of those neural signals into structured, conscious percepts. These processes are sometimes called sensation and perception, respectively. There seems to be no clear border between them, however; rather, sensation flows smoothly into perception. The latter explains why we usually see whole scenes rather than swirls of megapixels or innumerable separate pieces of a jigsaw puzzle. Determining how we perceive wholes rather than just local parts has proven to be a challenge.

Perceptual organization is an important part of that second process in vision because it deals with how those elementary pieces, sometimes called basic features, are assembled into organized wholes. A commonly held view is that while the early phase of vision proceeds automatically and in parallel (simultaneously) across the visual field, the integration of the component features requires attention and takes place only within a limited region of space at any one time, within a spotlight of attention. If a red ball is tossed our way, one part of our visual system processes the wavelengths leading to red, another detects the curved edges defining a ball, another processes the motion of the ball toward us, and yet others detect the ball's size, texture, and spin. These components are subsequently combined into final percepts through attention, a process called feature binding.