Created by Mary Coffelt and her colleagues at the Barrow Neurological Institute, this version of Akiyoshi Kitaoka's "Bulge" illusion uses strategically placed white and purple M&Ms to warp your perception of a checkerboard built from legos of the same color. (Hit the jump to see a video of the Bulge illusion in action.)

[SciAm bwo Boing Boing]