Sunday, March 7, 2010

Seeing faces

In 1976 NASA's Viking 1 Mars Lander spacecraft took a photograph of the surface of the Cydonia region of Mars that was to become rather controversial over the years. In the poor resolution available to Viking's camera, it appears to show a human face on the surface of Mars. Over the years higher resolution pictures became available and the clearer the picture the less evidence there is for a face.

Yesterdays post made me have to go and look up a word I couldn't remember - Pareidolia. This is the psychological phenomenon involving a vague visual image being perceived as significant.

As biologists though we want to dig a little deeper. Why do we see faces everywhere we look - in clouds, on the moon, in squid and on grilled cheese sandwiches? The New York Times had a good article on this a couple of years ago.

Compelling answers are beginning to emerge from biologists and computer scientists who are gaining new insights into how the brain recognizes and processes facial data.

Long before she had heard of Diana Duyser’s grilled-cheese sandwich, Doris Tsao, a neuroscientist at the University of Bremen in Germany, had an inkling that people might process faces differently from other objects. Her suspicion was that a particular area of the brain gives faces priority, like an airline offering first-class passengers expedited boarding.

The bottom line:

“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.”

No comments: