The phenomenon of near-death experiences (NDEs) has fascinated humanity for centuries but remains famously difficult to define and study. This book presents a unique source, integrating historical, clinical, psychological, and neuroscientific approaches toward a modern scientific understanding of NDEs. Featuring exciting clinical and experimental details about processes in dying brains, it examines the physiological and psychological underpinnings of this extraordinary phenomenon. Chapters offer science-based accounts of NDEs as a natural part of the human condition informed by our biology and the remarkable capacities of the brain. By proposing that the origin of NDEs can be found in the physiology-dependent mental processes of the experiencer as expressed in altered states of consciousness, this book provides up-to-date insights for psychologists, psychiatrists, neuroscientists, and philosophers alike.