Near-death Experiences Explained

[Tank]

Near-death Experiences Explained

Do you believe in life after death?

Many people believe in ghosts and heaven, and about three in 100 Americans report actually having near-death experiences. These typically include an awareness of being dead, out-of-body experiences, meeting dead people, entering tunnels of light, and so on.

But these are stories and anecdotes; what does science have to say?

A new article published in Trends in Cognitive Sciences by neuroscientist Dean Mobbs, of the University of Cambridge's Medical Research Council Cognition and Brain Sciences Unit, and Caroline Watt, of the University of Edinburgh, finds that "contrary to popular belief, research suggests that there is nothing paranormal about these experiences. Instead, near-death experiences are the manifestation of normal brain function gone awry, during a traumatic, and sometimes harmless, event."...

Scientific study of NDA.

[Squid]

Very cool. Thanks for the link.  I've always found the research on NDEs and OBEs very interesting especially since they've long be utilized and "irrefutable proof" of everything from a "soul" to an "afterlife" and by proxy substantiation of religious tenets.

[xSilverPhinx]

Going by anecdotal stories of people who had NDEs, even an atheist says that she saw a tunnel of white light and a human figure appear:

http://www.youtube.com/watch?v=wt0w7KF9eT0&list=FLvmSEhPwexnJ7FYkh4LjBdQ&index=4

[Recusant]

Review paper on studies of the phenomenon. 

"Neuroscientific model of near-death experiences finds consistent physiological pattern" | Medical Xpress

A multidisciplinary team led by the University of Liège has proposed a unified neuroscientific model explaining the mechanisms behind near-death experiences (NDEs), drawing on converging empirical findings across neurobiology, psychology, and evolutionary theory.

Findings suggest that factors such as oxygen deprivation, increased carbon dioxide, and disrupted brain energy metabolism can initiate brain responses that lead to vivid perceptual and emotional experiences often reported during NDEs.

Subjects reporting NDEs describe a wide range of phenomena, though typically only certain types of experiences are elevated to the level of public interest. Some of the more commonly retold types of NDEs include:

• Out-of-body experiences, where there is a dissociative sense of leaving the physical body.
• Distorted awareness of time, with a sense that time has slowed down, stopped, or accelerated.
• An emotional sense of calm, peace, and well-being.
  
• A flood of memories or having one's life "flash" before their eyes.
  
• Bright lights, long tunnels, and visitations by deceased relatives or unknown figures perceived as sentient, mystical, or spiritual imagery.

Many intriguing NDEs capture the imagination, and selection bias pushes us toward focusing on experiences that appear thematically repetitive. Less retold are NDEs that, though just as vivid, contain nightmarish, mundane, or nonsense themes. Subjective states resembling NDEs can occur in both life-threatening and non-life-threatening situations, such as fainting and drug use.

[Continues . . .]

The paper is behind a paywall.

Abstract:

Near-death experiences (NDEs) are episodes of disconnected consciousness that typically occur in situations that involve an actual or potential physical threat or are perceived as such, and the experiences are characterized by a rich content with prototypical mystical features.

Several explanatory theories for NDEs have been proposed, ranging from psychological or neurophysiological to evolutionary models. However, these concepts were often formulated independently, and, owing to the fragmented nature of research in this domain, integration of these ideas has been limited. Lines of empirical evidence from different areas of neuroscience, including non-human studies, studies investigating psychedelic-induced mystical experiences in humans, and research on the dying brain, are now converging to provide a comprehensive explanation for NDEs.

In this Review, we discuss processes that might underlie the rich conscious experience in NDEs, mostly focusing on prototypical examples and addressing both the potential psychological mechanisms and neurophysiological changes, including cellular and electrophysiological brain network modifications and alterations in neurotransmitter release. On the basis of this discussion, we propose a model for NDEs that encompasses a cascade of concomitant psychological and neurophysiological processes within an evolutionary framework. We also consider how NDE research can inform the debate on the emergence of consciousness in near-death conditions that arise before brain death.