Near-death experience: Difference between revisions
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== Reported mechanisms == | == Reported mechanisms == | ||
Not everyone agrees about what causes an NDE | Not everyone agrees about what causes an NDE. | ||
Neuroscientist Mario Beauregard examined the brains of 15 people who reported | Neuroscientist Mario Beauregard examined the brains of 15 people who reported NDEs. The participants relived their experiences while Beauregard completed the exam using [[electrodes]] and an isolation chamber. Beauregard noted there was a shift in their brain and the shift would allow these people to stay in touch with the spiritual world.<ref>Beauregard M ''et al.'' (2009) Brain activity in near-death experiencers during a meditative state ''Resuscitation'' 80:1006-10 PMID 19573975</ref> | ||
Pyschiatrist Karl Jansen attributes NDEs to “underlying mechanisms in more mysterious realms that cannot currently be described." He attributes NDEs partly to neurochemistry and [[psychology]]. <ref name=TIME>{{cite web | Pyschiatrist Karl Jansen attributes NDEs to “underlying mechanisms in more mysterious realms that cannot currently be described." He attributes NDEs partly to neurochemistry and [[psychology]]. <ref name=TIME>{{cite web |
Revision as of 08:51, 2 November 2011
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Near-death experience, also known as NDE, is the common name for feelings, impressions and out-of-body experiences reported by people who have been resuscitated.[1]
Such reports date back to the time of Plato who wrote about the Myth of Er.[2], but the term near-death experience was coined by a psychologist, Raymond Moody, in his bestselling book, Life after Life, first published in 1975.[3] The book was a compilation of the experiences reported by more than 100 people who came close to death. Moody believes in an afterlife, and regards these reports as possible supporting evidence for this, while recognising that there are other explanations. Generally however, scientists consider that NDEs arise from the disordered activity of a brain under extreme stress that is interpreted in a way conditioned by expectations. [4]
In a later book, Moody wrote: “By the classical definition, death is the state from which you don't return. It is defined as irreversible. Hence, since all of the NDEers returned, they were never really dead. What happened was that various criteria for death were fufilled" [5] [6] Both adults and children report similar NDE experiences.[7] Similar experiences have been reported by others, including when someone is participating in meditation, under emotional duress or at the bedside of a dying loved one.
Did the NDE experiencer really die?
The immediate reactions to Moody's book were very polarised; some embraced the reports as endorsing their belief in an afterlife, others dismissed the reports as hallucinatory delusions or mere inventions. Moody's book was simply a compilation of anecdotes. However, other researchers since then have consistently found that NDEs are a relatively common occurrence, and follow a quite consistent narrative form in many different cultures and in historical accounts. This suggests that NDEs share a common neurological basis, and various theories have been proposed, for example, that neuronal dysfunction due to anoxia and/or carbon dioxide overload leads to a sequence of disordered brain activity that is subsequently interpreted as an "experience" in a way conditioned by expectations.[8]
Even if the NDE has a relatively prosaic explanation, the impact of an NDE on the lives of those who have experienced one is often considerable. There are many accounts of an NDE changing a person's values, making them less afraid of death, more religious and less materialistic. Conversely, an NDE apparently led Hong Xiuquan to believe that he was the brother of Jesus Christ, and he went on to lead a rebellion that claimed at least 20 million lives. [9]
Scales
In 1980, psychologist Kenneth Ring developed a 10 point interview scale, which he used to interview 102 people who had come close to death. The interview using the scale determined that 48% of Ring's group had had an NDE. Using this information he developed the Weighted Core Experience Index. [10] This index asked about whether the NDE was peaceful; involved an Out-of-Body Experience (OBE); tunnel or dark area; saw a light; entered the light.
The Greyson Scale was developed by psychiatrist Bruce Greyson after he interviewed 74 people who reported an NDE. [11] [12][13] He used the 16 most frequently reported features to develop his questionaire, which sought to establish whether there had been: an experience of altered time; accelerated thought process; a life review; a sense of sudden understanding; feelings of peace/joy/'cosmic oneness'; seeing or feeling the surrounding of light; reporting vivid sensations; extrasensory perception (ESP); experiencing visions; an OBE; a sense being in an 'otherworldly environment', of a mystical entity; of deceased or religious figures; or of a 'border' or point of no return. Each question is rated 0, 1 or 2. The potential maximum score was 32 and a score of 7 was needed to qualify for having an NDE. [10] There are variances between adults and children in what they may experience and describe concerning the NDE. Cultural variations concerning NDEs have also been reported.
Incidence
In The Light Beyond, Moody explained that people often reported the following:
- a "sense of peace and painlessness”. Cardiac patients, according to Moody, report the intense pain of a heart attack turns into pleasure.
- an "Out-of-Body Experience" (OBE): Moody reports his study subjects described seeing their body below while retaining a “body” of some sort they can not describe.
- a tunnel. “The descriptions are many, but the sense of what is happening remains the same: the person is going through a passageway toward an intense light” .
- 'People of Light', that glow with intense luminescence that fills the person with love. The light is described as being much brighter than anything found on earth while not hurting the eyes. The person under-going this experience may see friends and relatives who have died.
- Being of Light: The NDE witness will report seeing a holy supreme being of light. When meeting this holy being the person wants to remain but is told by the being of light to return to their earthly body.
- Life Review: “The closest description I've heard of it is that the whole person's life is there at once,” writes Moody. Moody states the NDE experiencer comes away from the experience realizing the most important things in life are love followed by knowledge.
- Return: NDE experiencers want to remain in the heavenly place and often experience short-term anger when they are brought back from death states.
In 1982, a Gallup poll survey in the United States, where most people believe in an afterlife, estimated that approximately 8 million people had had an NDE.[10] Of those, 26% described an OBE; 23% felt that they had experienced accurate visual perception; 17% heard sounds or voices; 32% feelings of peace or painlessness ; 14% saw light phenomena; 32% described having a life review ;32% being in another world ;23% encountering other beings; 9% described a tunnel experience; and 6% described a sense of precognition .
In 2011, the journal Trends in Cognitive Sciences published a paper entitled 'There is nothing paranormal about near-death experiences: how neuroscience can explain seeing bright lights, meeting the dead, or being convinced you are one of them'. The paper, by neuroscientists Dean Mobbs and Caroline Watt, summarised the results of various scientific studies of NDEs. [14]
A commonly reported features of NDEs is an awareness of being dead - but these feelings are not limited to NDEs. A condition called "Cotard" - or "walking corpse" syndrome, where a person believes they are dead, has been seen after trauma and during the advanced stages of typhoid and multiple sclerosis.[15] Out-of-body experiences can be artificially induced by stimulating the right temporoparietal junction in the brain, an area that has a role in perception and awareness.[16] The "tunnel of light" sensation can also be artificially induced: pilots flying at G-force can experience "hypertensive syncope" which causes tunnel-like vision for up to eight seconds [17], and one study suggests that the light at the end of the tunnel is explained by poor blood and oxygen supply to the eye.[18] The feelings of bliss and euphoria, meanwhile, can be recreated with drugs such as ketamine and amphetamine.
Physician Sam Parnia states that, in his study of cardiac-arrest survivors, around 6% had an NDE (4 out of 63). In his book What Happens When We Die Parnia states that the oxygen levels were higher in the NDE patients than in the study control group.[10]
Non-Western experiences
"I died, as you know. I seemed to leave my body and stand beside it, looking down on what was me. The me that was standing there looked like the form I was looking at, only, I was alive and the other was dead. I gazed at my body for a few minutes, then turned and walked away. I left the house and village, and walked on and on to the next village, and there I found crowds of people,—Oh, so many people! The place which I knew as a small village of a few houses was a very large place, with hundreds of houses and thousands of men, women, and children. Some of them I knew and they spoke to me,—although that seemed strange, for I knew they were dead,—but nearly all were strangers. They were all so happy! They seemed not to have a care; nothing to trouble them. Joy was in every face, and happy laughter and bright, loving words were on every tongue." From Hawaiian Folk Tales (1907) [19]
The Handbook of Near-Death Experiences summarises reports collated in 16 refereed journal articles describing more than 275 non-Western NDEs, gathered since 2005. The experiences are from Asia, Pacific area and hunter-gatherer cultures.[20]
China
Based on the historical work of Carl Becker and the empirical work by Fen Zhi-ying and Liu Jian-xun the following information was collected. Becker interviewed three Chinese Buddhist monks who were seriously ill and either had a NDE or or deathbed vision. No tunnel of light was reported by the monks although one did report “going through a void”. None reported an OBE or life review; all three reported visiting the “pure land.”
Medical doctors Zhi-ying and Jian-xun interviewed 81 survivors of the Tangshan earthquake. They found 32 NDE experiencers who reported most of the similar experiences found in Western NDE studies. The Chinese earthquake survivors reported OBEs, the tunnel experience, peace, life reviews, seeing deceased beings and seeing an unearthly realm of existence.
India
K. Osis and E. Haraldson interviewed 704 Indian medical personnel in 1977. The interviews dealt with their experiences with the dying. The interviews showed that 64 participants reported an NDE while the rest reported near-death visions. Satwant Pasrich and (first name unknown) Stephenson in 1986 reported 16 cases of NDE in India. Of the 16 reports, 10 of the reporting witnesses were directly interviewed. By 1993, a total of 45 cases were reviewed. The researchers found no evidence of tunnel of light and one person reported an OBE. [20]
Thailand
Researcher Todd Murphy in 2001 collected 10 published NDE accounts. There was one report of an OBE but Murphy believed the Yamtoots, guides of the underworld, served the this function. No tunnel or tunnel-like experiences were reported by Murphy other than the one case reported. He wrote “tunnels are rare, if not absent, in Thai NDEs.” [20]
New Zealand
Researcher Michael King reported in 1985 the report of a Maori woman who died and reported hovering over her body. She later ascended to a ledge and looked at the entrance of the underworld. She performed a dance in preparation of entering the underworld. As she prepared to enter, a voice told her it was not her time and she returned to her body. [20]
Children
Pediatrician Melvin Morse became interested in NDEs after one of his patients told about her NDE. She was resuscitated after nearly drowning. Katie spent three days near the brink of death and was kept in a deep coma. On the third day she awoke as if from a deep sleep and by the next day was visiting with family. She showed no signs of brain damage. Morse interviewed the girl about what she remembered from the experience and was told about her visit to heaven. Morse reports a person actually needs to be near death to have a near-death experience. He also reports the ara in the brain near the right temporal lobe is genetically coded for near-death experiences, forward to the book Closer to the Light. [21]
Morse created the Seattle Study to determine if someone needed to be near death in order to have an NDE. The control group of 121 seriously ill children had a less than five percent chance of dying but were ill. Morse interviewed children based on the psychological experience of being in an intensive care unit with no mention of NDEs. Interviews lasted approximately two hours and asked questions such as what the patient remembered while being sick, dreams and hospital experiences. 118 of the children who were seriously ill, but not close to death, did not remember their hospital experience.
The experimental group, the cardiac survivors or ones who awoke from deep comas, most of the children did report at least one feature of the NDE. Morse states the child would often start telling of their experience with a puzzled look. He gave the example of “Well, I kind of remember a really funny thing that I can't exactly telly. I was looking at myself and going somewhere, but I didn't exactly know where,” p. 23 Closer to the Light. Morse said the children would go onto tell about their NDE. Some of the children were not affected by the experience while others were profoundly affected. [21]
Hellish NDEs
Key reported components of the hell-like NDE include seeing lifeless or threatening apparitions; barren or ugly landscapes; hearing threats, screams or perceiving silence; feeling a sense of danger or the possibility of violence including torture; a feeling of cold or temperature extremes and a sense of hell[20].
A study conducted by Hubert Knoblauch, Ina Schmied and Bernt Schnetter involved 82 German participants, of these, 4% reported NDEs; 60% of the West German correspondents reported positive NDEs (or emotions) while 29% reported negative NDEs (or emotions), whereas the East German participants reported 40% positive and 60% negative experiences. “The authors concluded that not only the interpretation but 'also the very content of what is experienced...is culturally constructed.” [20]
Montana State University Health Science Professor William Serdahely reported that 4 of 12 NDE experiencers considered the experience scary or frightening[20]. The scantiness of statistics concerning hellish NDEs may be based upon the lack of wanting to disclose this experience states medical social worker Kimberly Clark Sharp. She says people will call and start to discuss their negative experience and then change their mind. [20]
Theories of what may cause an NDE
NDEs seem to be relatively common in cardiac arrest patients after successful resuscitation, with an estimated incidence of 11 to 23%.[22]One prospective study of 52 patients with out-of-hospital cardiac arrest reported that 11 had experienced an NDE, and that this was connected to higher initial partial pressures of end-tidal CO2, higher arterial blood CO2 levels, and previous NDEs. Higher serum levels of potassium might also play a role. During cardiac arrest, the end-tidal CO2 falls to very low levels, reflecting the very low cardiac output achieved with cardiopulmonary resuscitation. CO2 levels affect the acid-base equilibrium in the brain, and this can provoke unusual experiences in the form of bright light, visions, and out-of-body experiences [23]
In 2007, the New England Journal of Medicine published a report of a patient, in whom electrodes had been implanted to suppress tinnitus, who repeatedly experienced an out-of-body experience during stimulation of part of the superior temporal gyrus. Positron-emission tomographic scanning showed brain activation at specific brain sites following stimulation, and the authors suggested that the experience of disembodiment is mediated by coactivation of a small area at the junction of the angular and supramarginal gyrus, which affects vestibular–somatosensory integration of body orientation in space, and the posterior part of the superior temporal cortex, which is believed to be involved in processing an internal map of self-perception. They suggest that these same regions may be activated in patients who report disembodiment as part of an NDE.[24]
The Birth Tunnel experience
Astronomer Carl Sagan proposed the NDE is a leftover birth memory. Sagan writes in Broca's Brain: Reflections on the Romance of Science every human being has the shared experience of birth to back up his theory.
Near-Death-Like experiences that are not
One view of NDEs is to include them in the large group of phenomena in which changes in the body seem related to mental or spiritual experiences. There are many of these, from mediation and fasting to ceremonial intoxicants to forty days in the wilderness. In any of them, the effects have been interpreted as anything from madness to divine inspiration. See Mysticism for discussion.
Morse [5] rejects this view, and considers none of the following to be NDEs:
- LSD – People who use this drug may feel like they've left their bodies. They also know they are not experiencing reality.
- Morphine and Heroin – People using these drugs usually do not perceive this experience as real, nor does it usually involve seeing the tunnel of light, seeing the light, or having visions of heaven.
- Recreational drugs such as marijuana, cocaine, amphetamines and barbituates tend to cause paranoia, speech disturbances, loss of control of thought processes, poor memory, depression and fear, but not NDE-like experiences.
- Anesthetic Agents – halothane, surital, nitrous oxide, narcotics, and nembutal do not cause hallucinations, although the patient may hear conversations while under the influence of one of these agents and become confused.
- Ketamine – Another anesthetic agent no longer used. When used, patients reported frightening OBEs and they may have seen mirror images of themselves (autoscopic) when under the influence of this agent. Patients also know they are under the influence of drugs during this experience.
- Transient Depersonalization – The person becomes emotionally detached from their bodies during a near-fatal experience. Morse found no evidence of this in the children he interviewed after their NDE.
Reported mechanisms
Not everyone agrees about what causes an NDE.
Neuroscientist Mario Beauregard examined the brains of 15 people who reported NDEs. The participants relived their experiences while Beauregard completed the exam using electrodes and an isolation chamber. Beauregard noted there was a shift in their brain and the shift would allow these people to stay in touch with the spiritual world.[25]
Pyschiatrist Karl Jansen attributes NDEs to “underlying mechanisms in more mysterious realms that cannot currently be described." He attributes NDEs partly to neurochemistry and psychology. [26]
Neurologist Kevin Nelson believes that the explanantion for NDEs lies within the brain itself. He attributes NDEs to Rapid Eye Movement (REM) state, and believes that the NDE bright light is caused by visual stimulation in the brain due to the REM, while the 'tunnel' is caused by a decrease of blood flow to theeye.[27]
Mark Mahowald, director of the Minnesota Regional Sleep Disorders Center, believes there is nothing mysterious about NDEs. He attributes NDEs to oxygen starvation in the brain.[26]
Laboratory-induced NDE
Recently, it has been established that the spectrum of effects attributed to near-death experiences can be fully reproduced, at will, by area-specific stimulation of the brain by magnetic resonance imaging techniques in combination with sensory deprivation.
The seat of the soul
There are many theories on what causes an NDE, but none have been proven. Morse writes in Closer to the Light the right temporal lobe when electrically stimulated has caused patients to report 'seeing God'. He first came up with this theory after discussing NDEs with Art Ward who was the chairman of neurosurgery at the University of Washington. During their conversation, Ward reported many of his own patients had reported similar experiences. He recalled one patient who experienced every trait of the NDE experience after an area of his brain was examined with an electric probe (by Wilder Penfield). After this discussion between Morse and Ward further research was done concerning Penfield's work. The area being mapped was called the Sylvian fissure located in the area of the right temporal lobe, p. 104-105 Closer to the Light. Researchers in Chile confirmed that near-death experiences were caused by neuron activity within the Sylvian fissure.
“Learning that other scientists had reached the same conclusion independently told us that we had at least discovered the circuit boards of mysticism. In our hearts, some of us believed strongly that we had discovered the seat of the soul” p. 110 Closer to the Light.
References
- ↑ Blackmore SJ (1996) Near-death experiences J R Soc Med 89:73-6. Review. PMID 8683504
- ↑ Myth of Er (Plato, Republic X). Retrieved on 2011-01-11.
- ↑ Raymond Moody (2001) Life After Life: the investigation of a phenomenon – survival of bodily death, San Francisco, CA: Harper SanFrancisco ISBN 0-06251739-2
- ↑ Near-death experience 'all in the mind' 'BBC News 31 October 2011
- ↑ Jump up to: 5.0 5.1 5.2 Perry, Paul; Moody, Raymond A (1988). The Light Beyond. New York: Bantam Books. ISBN 0-553-05285-3.
- ↑ Eelco FM et al. (2010) Evidence-based guideline update: Determining brain death in adults: Report of the Quality Standards Subcommittee of the American Academy of Neurology Neurology 74:1911>
- ↑ Morse M et al. (1985) Near-death experiences in a pediatric population Am J Dis Child139:595-600 PMID 4003364
- ↑ Blackmore SJ (1996) Near-death experiences J R Soc Med 89:73-6. Review. PMID 8683504
- ↑ God's Chinese Son: The Taiping Heavenly Kingdom of Hong Xiuquan
- ↑ Jump up to: 10.0 10.1 10.2 10.3 Parnia S (2006). What happens when we die: a groundbreaking study into the nature of life and death. Carlsbad, CA: Hay House. ISBN 1-4019-0710-5.
- ↑ Greyson B (2003) Near-death experiences in a psychiatric outpatient clinic population Psychiatr Serv 54:1649-51 PMID 14645808
- ↑ Greyson B (2010) Hypercapnia and hypokalemia in near-death experiences Crit Care 14:420 PMID 20519028
- ↑ Griffith LJ (2009) Near-death experiences and psychotherapy Psychiatry (Edgmont) 6:35-42 PMID 20011577
- ↑ Mobbs D, Watt C (2011) There is nothing paranormal about near-death experiences: how neuroscience can explain seeing bright lights, meeting the dead, or being convinced you are one of them Trends in Cognitive Sci 15:447-9
- ↑ McKay RL, Cipolotti L (2007) Attributional style in a case of Cotard delusion. Conscious Cogn (2007) 16:349–59
- ↑ Blanke O. Arzy S (2004) The out-of-body experience: disturbed self-processing at the temporo-parietal junction Neuroscientist 11:16–24
- ↑ Lambert EH, Wood EH (1946) Direct determination of man's blood pressure on the human centrifuge during positive acceleration Federation Proc 5:59
- ↑ Nelson KR et al. (2007) Out-of-body experience and arousal. Neurology 68:794–5
- ↑ Hawaiian Folk Tales (1907) Ed Thomas G. Thrum Project Gutenberg
- ↑ Jump up to: 20.0 20.1 20.2 20.3 20.4 20.5 20.6 20.7 Cite error: Invalid
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tag; no text was provided for refs namedHandbook
- ↑ Jump up to: 21.0 21.1 Perry P; Morse M (1990). Closer to the light: learning from children's near-death experiences. New York: Villard Books. ISBN 0-394-57944-5.
- ↑ Parnia S et al. (2007) Near death experiences, cognitive function and psychological outcomes of surviving cardiac arrest Resuscitation 74:215-21 Review. PMID 17416449
- ↑ Klemenc-Ketis et al. (2010) The effect of carbon dioxide on near-death experiences in out-of-hospital cardiac arrest survivors: a prospective observational study Crit Care 14:R56 PMID 20377847
- ↑ De Ridder D et al. (2007) Visualizing out-of-body experience in the brain N Engl J Med 357:1829-33 PMID 17978291
- ↑ Beauregard M et al. (2009) Brain activity in near-death experiencers during a meditative state Resuscitation 80:1006-10 PMID 19573975
- ↑ Jump up to: 26.0 26.1 At the Hour Of Our Death - TIME=. Retrieved on 2011-01-11.
- ↑ Doctor says near-death experiences are in the mind - Page 2 - CNN. Retrieved on 2011-01-11.