Near-death experience: Out-of-body and out-of-brain?

During the last decades, several clinical cases have been reported where patients described profound subjective experiences when near-death, a phenomenon called "near-death experience" (NDE). Recurring features in the accounts involving bright lights and tunnels have sometimes been interpreted as evidence of a new life after death; however the origin of such experiences is largely unknown, and both biological and psychological interpretations have been suggested. The study of NDEs represents one of the most important topics of cognitive neuroscience. In the present paper the current state of knowledge has been reviewed, with particular regard to the main features of NDE, scientific explanations and the theoretical debate surrounding this phenomenon