Our brain can tell real face from imitations

Both the right and the left sides of the brain work together to tell a real face from a facial imitation, says a study co-authored by an Indian-born scientist.

Objects that resemble faces are everywhere. Whether it’s New Hampshire’s erstwhile granite ‘Old Man of the Mountain’, or Jesus’ face on a tortilla, our brains are adept at locating images that look like faces.

However, the normal human brain is almost never fooled into thinking such objects actually are human faces.

“You can tell that it has some ‘faceness’ to it, but on the other hand, you’re not misled into believing that it is a genuine face,” says Pawan Sinha, professor of brain and cognitive sciences at the Massachusetts Institute of Technology (MIT).

On the left side of the brain, the fusiform gyrus, an area long tied with face recognition, calculates how ‘facelike’ an image is. The right fusiform gyrus then appears to use that information to make a quick, categorical decision of whether the object is, indeed, a face, the journal Proceedings of the Royal Society B reports.

This distribution of labour is one of the first known examples of the left and right sides of the brain taking on different roles in high-level visual-processing tasks, says Sinha, study co-author. But hemispheric differences have been seen in other brain functions, most notably language and spatial perception, according to an MIT statement.

Ming Meng, who used to do research in Sinha’s lab and is now an assistant professor at Dartmouth College, led the study.