Seeing Faces

What makes us see Jesus in a taco, or a human face on Mars?

Photographer Todd Terwilliger calls this picture “Skull Flower,” for reasons that should be obvious. Its resemblance to a human cranium is, of course, purely coincidental — yet the urge for our minds to register this plant as a piece of human anatomy is all but impossible to resist. But why?

The one-word answer, as some of you may know, is “pareidolia.” But here’s what you don’t know: scientists this week presented some of the most compelling evidence to date that this pscyhological phenomenon is mediated by a region of the brain known as the fusiform gyrus. 

How did they find this culprit? Simple: by jolting that part of the brain with electricity, and watching their test subject’s perception of reality liquefy into mind-bending absurdity.

Basically, we humans have this niggling habit of extracting what we believe to be significant information from patently insignificant stimuli. It’s where we get Jesus-toast, and why we find familiar objects in shape shifting cumulus, like this face on the surface of Mars:



And, of course, skulls (not to mention other anatomical features) in flowers. Point being: our brains are wired-up in such a way that we often see things that aren’t really there — but again: why? For pareidolia in general the answer is somewhat muddled; but on the subject of faces, specifically, scientists have some very strong leads.

The leading hypothesis is that our tendency to recognize faces in nonhuman objects is a highly evolved survival trait. As Carl Sagan wrote in The Demon-Haunted World:

As soon as the infant can see, it recognizes faces, and we now know that this skill is hardwired in our brains. Those infants who a million years ago were unable to recognize a face smiled back less, were less likely to win the hearts of their parents, and less likely to prosper. These days, nearly every infant is quick to identify a human face, and to respond with a goony grin.

This makes a lot of sense. Being able to not only spot a face, but decipher the emotional, social, or sexual cues signalled by that visage, could score you a meal, save your life, or land you a mate — all things that are crucial to the propagation of your genes.

Scientists have traced our ability to perceive faces to a few key regions of the brain. Functional MRI, positron emission tomography, and other brain-imaging studies, for example, have shown that the fusiform gyri and the inferior temporal gyri light up when a person is shown pictures of faces, or objects resembling faces. 

Damage to the fusiform area is known to give rise to prosopagnosia, a neurological disorder (more commonly known as “face blindness”) characterized by the inability to recognize faces.