Your neurons register familiar faces, whether you notice them or not

When people see an image of a person they recognize—the famous tennis player Roger Federer or actress Halle Berry, for instance—particular cells light up in the brain. Now, researchers reporting in Current Biology on September 21 have found that those cells light up even when a person sees a familiar face or object but fails to notice it. The only difference in that case is that the neural activity is weaker and delayed in comparison to what happens when an observer consciously registers and can recall having seen a particular image.