How does our brain know what is a face and what’s not?
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 MIT.A new study from Sinha and his colleagues reveals the brain activity that underlies our ability to make that distinction. On the left side of the brain, the fusiform gyrus — an area long associated with face recognition — carefully calculates how “facelike” an image is. The right fusiform gyrus then appears to use that information to make a quick, categorical decision of whether...