NET PICS: Eye Twisters

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Science  22 May 1998:
Vol. 280, Issue 5367, pp. 1163
DOI: 10.1126/science.280.5367.1163c

Your mind will try to convince you otherwise, but the light square within the cylinder's shadow is in fact the same shade as the dark squares outside the shadow. The illusion by the Massachusetts Institute of Technology's Ted Adelson is among several hundred on a Web site created by California Institute of Technology cognitive neuroscientist Al Seckel, vice president of a company called IllusionWorks LLC that produces exhibits for museums ( The site, hosted at Caltech, has page after page of mind-bending illustrations, from simple classics like “The Impossible Triangle” to interactive demos and artwork such as Swiss artist Sandro Del Prete's drawing “The Railway Bridge.” Seckel supplies references and explains the cognitive science behind many illusions, which he calls “a very nice window into how the brain works.”

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