Motion Aftereffect

The motion aftereffect (MAE) -is a visual illusion perceived after watching a moving visual stimulus for about a minute and then looking at stationary stimulus. The stationary stimulus appears to move slightly for about 15 seconds, opposite to the direction of the original (physically moving) stimulus. The motion aftereffect is believed to be the result of motion adaptation.

For example, if one looks at a waterfall for about a minute and then looks at the stationary rocks at the side of the waterfall, these rocks appear to be moving upwards slightly. The illusory upwards movement is the motion aftereffect. This particular motion aftereffect is also known as the waterfall illusion.