Understanding "the self" has long been thought to be neuroscience"s greatest challenge, a mystery perhaps that never can be solved. We are who we are, but mystics, Buddhists, and even scientists have told us the self is an illusion. We know who we are but then no matter how successful and healthy you are, sometimes we wonder, who is that inside our heads? Who am I really? Are you sure you know? With the explosion of progress in the scientific investigation of maladies such as schizophrenia, autism, Alzheimer"s, ecstatic epilepsy, and Cotard"s syndrome, as well as out of body experiences and Asperger"s, we are learning about the Self at a level of detail that Descartes ("I think therefore I am") could never have imagined. Is the Self merely your ongoing autobiography, your personal narrative, as Antonio Damasio has suggested? Alzheimer"s disease is illuminating the role of memory in the construction of that narrative as Ananthaswamy shows. The same part of your brain that remembers...