By Susana Martinez-Conde and Stephen L. Macknik
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.
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.