Name: Why do we see illusions?
Uploaded: 2019-02-12T22:30:57Z
Duration: 7 min 16 s
Description: Why can't our extremely complex eyes render simple optical illusions? Surprise, surprise -- it comes back to the brain, which has only evolved to encounter natural stimuli. At TEDYouth 2012, Mark Changizi explains how the brain reckons with optical illusions.[Directed by TED Media].

Why can't our extremely complex eyes render simple optical illusions? Surprise, surprise -- it comes back to the brain, which has only evolved to encounter natural stimuli. At TEDYouth 2012, Mark Changizi explains how the brain reckons with optical illusions.[Directed by TED Media].

Why do we see illusions?

The brain constantly tries to predict what will happen next, shaping perception in advance to keep up with a tenth-of-a-second delay. Even the simplest optical illusions fool our minds because they tap into processing built for survival in a fast-moving world. When parallel lines appear to bow or motion seems to blur, the brain is actually projecting what it expects to see in the immediate future. These illusions are not glitches, but signs of a brain fine-tuned for anticipation.