This photo of the World Trade Center burning on September 11 attracted a lot of attention for a curious pattern in the smoke. Was it the face of God? Satan?
Of course it was just a random pattern in the smoke that briefly seemed to look like a face, but many people were not convinced by appeals to rationality. Why is it that people seem to see faces so many places that there aren’t actually faces? The New York Times has an excellent article describing how and when we see faces.
As we’ve reported here before, even if you view a photo or painting at an extreme oblique angle, you can still see a face:
The Times article describes the research of Pawan Sinha, who has been working for some time developing computer models for recognizing faces:
As the computer amassed the information, 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.”
When he presented human subjects with blurry face images, containing only 12 by 14 pixels’ worth of visual information, they performed similarly well, recognizing 75 percent of the face images accurately. This suggests that like the computer, the human brain processes faces holistically, like coherent landscapes, rather than one feature at a time.
Hmmm… 12 by 14 pixels. Let’s see if we can reproduce that result here. Take a look at these pictures:
Which one is a face?
After we’ve gotten some results, I’ll reveal the correct answer in the comments.