Seeing faces everywhere

A cloud formation that some have interpreted as the face of God. (Credit, N.Y.Times)


Left: A grilled cheese sandwich, top, with an image of what some see as the Virgin Mary sold for $28,000 on eBay. Jesus Christ is seen in an oyster shell, a frying pan and a pirogi. (Credit, N.Y.Times).

Why do we see faces everywhere? An interesting article on this topic in this week's Science N.Y. Times. For some years, it has been known that specialized cells in our temporal lobes are strongly attuned to faces. Strokes in this region can cause prosopagnosia, the inability to recognize the faces of familiar people. Perhaps seeing faces where there are none in fact involves the activation of this area by non-face objects containing sufficient features to trigger the face cells.

Pawan Sinha of M.I.T., has developed face recognition software by giving the input of hundreds of faces; it was able to discover relationships that were of great significance to almost all faces, but very few nonfaces.

“These turn out to be very simple relationships, things like the eyes are always darker than the forehead, and the mouth is darker than the cheeks,” Dr. Sinha said. “If you put together about 12 of these relationships, you get a template that you can use to locate a face.”

"....whether the hair-trigger response to faces is innate or learned, it represents a critical evolutionary adaptation, one that dwarfs side effects like seeing Beelzebub in a crumpled tissue...The information faces convey is so rich — not just regarding another person’s identity, but also their mental state, health and other factors,” he said. “It’s extremely beneficial for the brain to become good at the task of face recognition and not to be very strict in its inclusion criteria. The cost of missing a face is higher than the cost of declaring a nonface to be a face.”