Put a hand on your widow's peak. About an inch below your fingertips in your medial prefrontal cortex is the home of your sense of self. Julian Keenan, director of the Cognitive Neuroimaging Lab at Montclair State University, did a nifty trick: He used what is effectively an electric Ping-Pong paddle to zap this region in healthy subjects, overexciting every neuron within range, and thus for about a fifth of a second, knocking that one-cubic-centimeter area of the brain off the grid.
And while he did this, he flashed pictures of faces. Blasted subjects retained the ability to recognize faces of loved ones or even learned strangers, but for this fifth of a second, they failed to recognize themselves.