Learn how the brain handles certain optical illusions, causing us to perceive shapes that don't actually exist.

New research into how the brain processes illusions has bombarded mouse neurons with lasers, artificially reproducing the brain activity.

Neuroscientists are zeroing in on how special kinds of brain cells help us see things that aren't actually there.

An illusion is when we see and perceive an object that doesn't match the sensory input that reaches our eyes. In the case of the image below, the sensory input is four Pac Man–like black figures.