motion aftereffect

n. The illusion that a stationary object is moving. After looking at a moving object for several seconds a stationary object will sometimes appear to be moving in the direction opposite to the thing that is actually moving. For instance, if an observer watches a long train go past and then sees a telephone pole behind the train, the telephone pole may appear to be moving toward the back of the train. Also called kinetic aftereffect and movement aftereffect.