Apparent movement occurs when an object is stationary but we perceive it to be moving. Two forms of apparent motion are stroboscopic motion and movement aftereffects. Stroboscopic motion is the illusion of movement created when a rapid stimulation of different parts of the retina occurs – motion pictures are a form of stroboscopic motion. Movement aftereffects happen when we watch continuous movement and then look at another surface, which then appears to move in the opposite directions.