How differences in color can make a still image move (The rotating snakes illusion)

Optical illusions trick our brains into seeing things that aren't happening. The rotating snakes illusion, created by Akiyoshi Kitaoka, appears to be moving, but it's a still image—not a gif not a movie. What's going on our brains that makes these concentric circles look as if they're rotating? <br /> <br />Learn more: pops.ci/SBiex1 <br /> <br />-- <br /> <br />Producer/Video by: <br />Jason Lederman <br />Tom McNamara <br /> <br />Research: <br />Marissa Shieh <br /> <br />Narrator: <br />Claire Maldarelli <br /> <br />Special Thanks: <br />Dr. Akiyoshi kitaoka <br />Rasmus Bååth <br /> <br />Cat/illusion video (courtesy Rasmus Bååth): <br />;https://youtu.be/CcXXQ6GCUb8 <br /> <br />Media used (CC BY 4.0): <br />;http://file.scirp.org/pdf/PSYCH_2014073015180838.pdf <br /> <br />-- <br /> <br />FOLLOW POPULAR SCIENCE <br /> <br />;https://www.popsci.com <br /> <br />Facebook: https://www.facebook.com/popsci <br /> <br />Twitter: https://www.twitter.com/popsci <br /> <br />Instagram: https://www.instagram.com/popsci <br /> <br />Snapchat: https://www.snapchat.com/add/popularscience <br /> <br />Pinterest: https://www.pinterest.com/popularscience