Spatial determinants of the aftereffect of seen motion

Observers were required to track the perceived motion of a stationary grating viewed following exposure to a moving grating. The size of the motion aftereffect was complexly controlled by relationships between the velocity and periodicity of the adaptation grating and the periodicity of the test grating. In addition the motion aftereffect was selective to the direction of motion of the adaptation grating. These results are considered in terms of a model attributing the motion aftereffect to selective postexcitatory suppression in the response of directionally-excited motion detectors in the visual system. © 1973.