Long-range interactions in visual perception.

Classical receptive-field concepts have been used to explain local perceptual effects such as border contrast and Mach bands, but are not sufficient to explain global perceptual effects. Examples are the perception of illusory contours, area contrast, color constancy, depth planes, coherent motion and texture contrast. These diverse effects require neurophysiological mechanisms within the visual pathways with long-range interactions. Candidate mechanisms are suggested, including converging feedforward projection to account for the emergence of new response properties at higher levels, recruitment of lateral connections to compensate for loss of afference and explain filling-in, and re-entrant projections from higher levels using synchronization of neuronal responses to account for binding.