People suffering from Cotard's Syndrome think they're dead. Victims of body integrity identity disorder believe their own limbs don't belong to them, and schizophrenics feel their thoughts aren't their own. By chipping away at our sense of a unified, stable self, these and other mental conditions hint at how selfhood might be assembled in the first place. What exactly is a self, anyway? Is it the product of specific neural mechanisms, or perhaps a psych-social construct? Does it ever go entirely away? Science writer Anil Ananthaswamy examines the evidence from neuroscience along with theories of the self from psychology, philosophy and spiritual traditions such as Buddhism, in his new book "The Man Who Wasn't There: Investigations into the Strange New Science of the Self."