The term illusory motion, also known as motion illusion, is an optical illusion in which a static image appears to be moving due to the cognitive effects of interacting color contrasts and shape position. Apparent motion is the most common type of illusory motion and is perceived when images are displayed in succession at a specific frame rate such as in a movie.
Using an fMRI, Roger B. H. Tootel et al. were able to identify the area of the brain that is active when experiencing illusory motion. Tootel and his colleagues had participants view a set of concentric rings that appeared to move inward and outward. Participants would experience a motion aftereffect after viewing the moving stimuli for 40 seconds. Participants showed an increased activity in the MT area of the brain.