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Illusion of the Week: Legos and M&M’s Bulge Illusion.

If you've ever played with Legos, you know that they're all about straight lines and 90-degree corners. Not in this version of Akiyoshi Kitaoka's "Bulge" illusion.

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Image credit: Mary Coffelt, Briena Heller, and Michael McCamy, Martinez-Conde and Macknik Laboratories, Barrow Neurological Institute

If you've ever played with Legos, you know that they're all about straight lines and 90-degree corners. Not in this version of Akiyoshi Kitaoka's "Bulge" illusion, created by Mary Coffelt, Briena Heller, and Michael McCamy in our laboratories last summer. The strategically placed purple and white M&Ms distort your perception of the Lego checkerboard, making it bulge out.

To see the illusion disappear with a single breath, watch this video.


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Read more about shape distortion illusions and their neural bases in our Illusions column

Susana Martinez-Conde is a professor of ophthalmology, neurology, and physiology and pharmacology at SUNY Downstate Health Sciences University in Brooklyn, N.Y. She is author of the Prisma Prize–winning Sleights of Mind, along with Stephen Macknik and Sandra Blakeslee, and of Champions of Illusion, along with Stephen Macknik.

More by Susana Martinez-Conde