This year’s best illusion reveals a visual quirk


Dot A mysterious illusion that illustrates how motion can render color changes invisible won the “Best Illusion of the Year” for 2011, and it also taught researchers something they didn't know. “It is a really beautiful effect, revealing something about how our visual system works that we didn't know before,” said Daniel Simons, a professor at the University of Illinois, Champaign-Urbana. Simons studies visual cognition, and did not work on this illusion. Before its creation, scientists didn't know that motion had this effect on perception, Simons said.

A viewer stares at a speck at the center of a ring of colored dots, which continuously change color. When the ring begins to rotate around the speck, the color changes appear to stop. But this is an illusion. For some reason, the motion causes our visual system to ignore the color changes. (You can, however, see the color changes if you follow the rotating circles with your eyes.) [See video of illusion winner] This illusion is the work of Jordan Suchow, a graduate student in cognitive science at Harvard University, and his adviser George Alvarez. Their illusion took first place at the conclusion of the seventh annual Best Illusion of the Year Contest in Florida. Suchow discovered it when his laptop, which was displaying a similar set of color-changing circles, slipped and the dots appeared to stop changing.

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