STANFORD, Calif. - You'll find more than faces in these places. Stanford University researchers have taken the closest look yet at a region of the brain that was thought to be devoted solely to face recognition and discovered that this particular patchwork of neurons does much more: It also responds to such objects as cars, animals and sculptures.
Current face perception theories suggest neurons in a portion of the brain called the fusiform gyrus light up in response to a face, leading researchers to refer to this region as the "fusiform face area." But a study to be published in the September issue of Nature Neuroscience reports that this area also shows a localized - albeit less extensive - response to more than just faces.
"We've looked at the fine structure of face-selective regions in the brain, and it argues against prevailing theories," said first author Kalanit Grill-Spector, PhD, assistant professor of psychology and a researcher in the Neuroscience Institute at Stanford.
Using high-resolution functional magnetic resonance imaging, Grill-Spector and colleagues imaged regions of the brain at a magnification of 27 to 70 times smaller than a traditional fMRI scan. Like viewing a grain of sugar rather than the whole cube, this allowed the team to "zoom in" on a hybrid of neural patches, each of which responds to a different category of objects.
"We were able to see things we haven't before," said Grill-Spector. "What's really cool is these structures are very selective in their responses - and only to one kind of object."
Each of the participants in the study was shown images of faces, four-legged animals, cars and abstract sculptures, along with scrambled or "noise" images. The researchers found that overall, twice as many of the patches are predisposed to faces versus inanimate objects, and that the patches that respond to faces outnumber those that respond to animals by 50 percent. Furthermore, same-select
Contact: Aditi Risbud
Stanford University Medical Center