FOLLOW MY FINGER: No matter from which direction you look at this image, the finger appears to be pointed directly at you.

This is the third article in the Mind Matters series on the neuroscience behind visual illusions.

The eyes are the windows to the soul. This fact is why we ask people to look us in the eye and tell us the truth. Or why we get worried when someone gives us the evil eye or has a wandering eye. Our everyday language is full of expressions that refer to where people around us are looking. Particularly if they happen to be looking in our direction. 

View Eye Illusions Slide Show

As social primates, humans are very interested in determining the direction of gaze of other humans. It’s important for evaluating their intentions, and critical for forming bonds and negotiating relationships. Lovers stare for long stretches into each other’s eyes, and infants focus intently on the eyes of their parents. Very young babies look at simple representations of faces (such as smileys) for longer than they look at similar cartoonish faces in which the eyes and other features have been scrambled.

In this slide show, we’re going to investigate a series of illusions that take advantage of the way the brain processes eyes and gaze. It turns out that it’s fairly easy to trick us into thinking that someone is looking somewhere else, or that Albert Einstein is actually Marilyn Monroe.

Mind Matters is edited by Jonah Lehrer the science writer behind the blog The Frontal Cortex  and the book Proust Was a Neuroscientist.

ABOUT THE AUTHOR(S)
Susana Martinez-Conde is director of the Laboratory of Visual Neuroscience at the Barrow Neurological Institute in Phoenix. She holds a Ph.D. in medicine and surgery from the University of Santiago de Compostela in Spain. Stephen L. Macknik is director of the Laboratory of Behavioral Neurophysiology at the Barrow Neurological Institute and earned a Ph.D. in neurobiology from Harvard University.