Near-death experience

A near-death experience (NDE) is the perception reported by a person who nearly died or who was clinically dead and revived. They are somewhat common, especially since the development of cardiac resuscitation techniques, and are reported in approximately one-fifth of persons who revive from clinical death. The experience often includes an out-of-body experience.

As a naturalistic experience

Other commentators see near death experiences as a purely naturalistic phenomenon. For example; a Swiss study (Blanke. et.al, 2002), published in Nature Magazine http://philosophy.hku.hk/courses/cogsci/files/Blanke,%20Ortigue%20-%20Stimulating%20illusory%20own-body%20perceptions.pdf, found that electrical stimulation on the brain region known as the right angular gyrus repeatedly caused out-of-body experiences to the patienthttp://www.cancerpage.com/news/article.asp?id=4883.

Related Topics:
Phenomenon - Swiss - Nature - Out-of-body experience

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A well-known scientific hypothesis that attempts to explain NDEs was originally suggested by accounts of the side-effects of the drug Ketamine by Dr. Karl Jansen (1995;1997). Ketamine was used as an anesthetic on U.S. soldiers during the Vietnam War; but its use was abandoned and never spread to civilian use because the soldiers complained about sensations of floating above their body and seeing bright lights. Further experiments by numerous researchers verified that intravenous injections of ketamine could reproduce all of the commonly cited features of an NDE; including a sense that the experience is "real" and that one is actually dead, separation from the body, visions of loved ones, and transcendent mystical experiences.

Related Topics:
Side-effect - Ketamine - Dr. Karl Jansen - Anesthetic - U.S. - Soldier - Vietnam War

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Ketamine acts in part by blocking the NMDA receptor for the neurotransmitter glutamate. Glutamate is released in abundance when brain cells die, and if it weren't blocked, the glutamate overload would cause other brain cells to die as well. In the presence of excess glutamate, the brain releases its own NMDA receptor blocker to defend itself; and it is these blockers Dr. Jansen (amongst others) hypothesize as the cause of many NDEs. Shawn Thomas, director of Neurotransmitter.net, has suggested that agmatine is the key substance involved in near-death experiences http://www.neurotransmitter.net/neardeath.html.

Related Topics:
NMDA - Neurotransmitter - Glutamate - Agmatine

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Critics of Jansen's hypothesis point out that although some aspects of the experience may be similar, not all NDEs exactly fit the ketamine experience; and that while it might be possible to chemically simulate the experience, this does not refute the possibility that spontaneous NDEs have a spiritual component. As Dr. Jansen himself notes:

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:Claims that NDE's must have a single explanation (e.g. Ring, 1980), or that a scientific theory must explain all of the experiences ever given the name of NDE (e.g. Gabbard and Twemlow, 1989) are difficult to justify (Jansen, 1995).

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Indeed Dr. Jansen's own shifting perspective on the conclusions to be drawn from the ketamine-NDE analogy has been notable. He started out as an unequivocal debunker of the notion that NDE's are evidence of a spiritual (or at least transnormal) realm. But with time he has developed a more agnostic hypothesis: that ketamine may in fact be one particularly powerful trigger of authentic spiritual experiences - of which near-death may be another. In each case, according to Jansen's more recent pronouncements, all we can say is that the subject gets catapulted out of ordinary 'egoic' consciousness into an altered state - we cannot comfortably rule out the possibility that the 'worlds' disclosed in these 'trips' have ontological status. Latterly, therefore, Jansens position appears closer to thinkers like Daniel Pinchbeck (2002), Carl Jung, Ken Wilber and Stan Grof, than to thinkers like Susan Blackmore (1993) or Nicholas Humphrey (two particularly high-profile materialist skeptics).

Related Topics:
Daniel Pinchbeck - Carl Jung - Ken Wilber - Stan Grof - Susan Blackmore - Nicholas Humphrey

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Also see: out-of-body experience in which experiences like NDE occur in epilepsy or during brain stimulation and lucid dreaming in which subjects also report experiences that seem more "real" than waking life.

Related Topics:
Out-of-body experience - Epilepsy - Lucid dreaming

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