Motion Perception

Motion perception is how your brain infers the speed and direction of any objects in your visual field. In terms of depth, your brain assumes that shrinking objects are retreating and enlarging objects are approaching. The brain is also tricked by movies and television, which are really a lot of images played in rapid succession. When we see it, however, the images appear to continuously move.

       
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This optical illusion is an example of motion perception. Although the sequence is really just oval like shapes of varying lengths, we perceive motion when we move our eyes from one side of it to the other.