Physiological Basis of Motion Perception

The perception of visual motion has fascinated psychophysicists for well over a century. During that time there has been a steady accumulation of information about motion without much accompanying theoretical structure. One recent development in visual physiology has begun to provide the basis for such a structure: the discovery in the mammalian visual system of direction-ally selective neurons, single cells that respond differentially to targets moving in different directions through the cells’ receptive fields. The likelihood that similar direction-selective cells play a role in the motion perception of humans (Grusser and Grusser-Cornehls, 1973) has heightened the psychophysicist’s interest in the neural mechanisms of motion.