Downstate Neuroscientists Bring the Science of Illusion into Focus

By Office of the President | Nov 3, 2026

Two identical gears turn at the same speed, yet one appears faster. Purple dots seem to change color as our eyes move. A sign reads true from one viewpoint and false from another. These illusions reveal something fundamental about human perception. What we see is not always a direct reflection of what is in front of us.

Downstate neuroscientists Susana Martinez-Conde, Ph.D., and Stephen Macknik, Ph.D., have spent years bringing that science to public attention through the Best Illusion of the Year Contest, which they founded to showcase how the brain interprets visual information.

The contest and its latest winners were featured in an October 27 Washington Post article by reporter Margaret Hetherman, titled How This Year’s Best Optical Illusions Trick Your Brain.

Now in its 20th edition, the competition draws submissions from scientists, artists, and creators around the world. This year’s finalists were selected by a panel of experts, with thousands voting online to choose the winners. The Museum of Illusions sponsored the competition.

The winning entry, Cogs in a Machine, by Canada’s Jacky Z.J. Yueh and Joan Danielle K. Ongchoco, uses peripheral vision to make one rotating gear appear faster than another, although both move at the same speed.

As Dr. Martinez-Conde explained, peripheral vision is particularly sensitive to motion, influencing how we perceive movement in everyday life.

Second-place winner 9 Purple Dots, by Harvard Medical School instructor Hinnerk Schulz-Hildebrandt, demonstrates how the focus of our attention can change color perception. Third-place winner The Hole Truth, by Britain’s Matt Pritchard, uses cutout letters and a mirror to show how perspective alters what we see.

Beyond their visual appeal, such illusions help scientists investigate the mechanisms of perception and how visual processing may change following neurological injury or disease.

At Downstate, Drs. Martinez-Conde and Macknik are also applying their expertise to research with clinical potential. Together with Stephen Waite, M.D., they are collaborating on a $2.7 million NIH-funded study examining how radiologists inspect medical images to improve training and reduce interpretation errors.

Their work connects fundamental neuroscience with questions that could ultimately influence clinical practice, demonstrating how a seemingly simple visual trick can reveal important insights into brain function.