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Near-Death Experience
The Near-Death Experience: All in the Head? Abstract: The key features and stages involved in the Near-Death Experience (NDE) are discussed and current research is examined in terms of modern psychology and physiology, in an attempt to find a causative explanation. The effectiveness of these current theories purported by the scientific community is evaluated in terms of finding a parsimonious understanding of this common phenomenon. The Near-Death Experience: All in the Head? Abstract: The key features and stages involved in the Near-Death Experience (NDE) are discussed and current research is examined in terms of modern psychology and physiology, in an attempt to find a causative explanation. The effectiveness of these current theories purported by the scientific community is evaluated in terms of finding a parsimonious understanding of this common phenomenon. Introduction : Research in to the NDE has stemmed from a collection of anecdotal accounts where the experience is more than just a strange event; those who have encountered it consider it to be a life changing moment – an epiphany. In the aftermath of the NDE, individuals transform their lifestyles opting for healthy living plans and tend to become spiritual people – not necessarily religious. People believe the NDE to be real event and claim that it is unlike any dream or ordinary experience. Since the study of NDE has progressed from philosophical speculation to psychology and medical science, it has opened doors to ideas that we may have ways of perceiving events other than via the known physical senses; furthermore the NDE has lead to more speculation that some part of the human personality survives beyond the physical death of the organism. Much of the theoretical work can provide some compelling and plausible hypotheses in explaining aspects of the NDE but there is a lack of evidence of any causation of the phenomenon. The components of the NDE vary from person to person but a list of common factors has been established and is generally accepted as the criteria for having had an NDE. According to Moody (1975) the NDE can typically include: feeling of having had an ineffable experience; overhearing news of their own death ( person is surprised by this); complacent feelings/bliss/euphoria – no pain despite a pain-filled body; buzzing/humming sounds can be heard; the Tunnel – feeling of being pulled through a void or passage; out- of -body experience (OBE) i.e. floating sensation and viewing ones own body from above; awareness of meeting other people i.e. deceased relatives; being engulfed by an increasingly bright light; life events/life history is flashed before them in a panoramic viewing style; finally the person makes decision to return to earth and the living. Although many describe their experience to others they do fear ridicule from others. The NDE was further reduced to 5 main stages by Ring ( 1980): 1 – Feelings of bliss/ euphoria 2 – Disconnection from their body (Autoscopy) 3 – Passage of darkness i.e. tunnel 4 – Experience of Light 5 – Entrance to the “other side” ( of the Light) There are no particular demographic factors which affect the rate of the experience. The NDE appears across ages, gender, race, religion and culture, however there are a few minor differences in the specific details such that Christian believers tend to interpret the being of light as Christ and Hindus interpret it as Krishna. Also when making the decision to return, Asian Indians tend to come back due to a beurocratic mistake i.e. “it wasn't their time”. The NDEs of children are remarkably similar to adults except that they report dead pets greeting them rather than relatives or religious figures. Another interesting point come from a study of death-bed visions (Osis and Haraldsson (1977) where people who are terminally ill (and expecting death) tend to have extremely pleasant experiences. and do not experience the panoramic life review. Perhaps there is room for speculation that those terminally ill have come to terms with and accepted death as a welcome release from a dying body, also having had time to reflect on their lives. Spiritual theory of NDE. There is a strong and prevalent belief among many that the NDE is clear evidence of an Afterlife and that at the moment of death, the spirit/soul leaves the physical body and this taken to be the mechanism of NDEs. Some researchers (Sabom, 1982) have taken the autoscopy element of the NDE to be evidence of this; his researched demonstrated that in some instances, the person viewing themselves from above were able to report information such as a number written on a high shelf – unseen from the lying position. However, these studies can be criticized as they are inconclusive and few. Even if we are to presume that individuals can “depart” in some sense from their physical bodies and report accurate information from this vantage point, it is not necessarily evidential of a soul/spirit or an afterlife. All that is demonstrated is some unusual ability related directly to human consciousness, perhaps remote viewing or Extra Sensory Perception. Furthermore, it has been noted that there are NDErs who have not been near death at all (merely perceived danger and threat to life) suggesting that death and near death states are not intrinsic to the NDE. This gives rise to a problem for NDE researchers in that there is confusion of the definition of NDE. The culture dependency is sometimes questioned as most of the research has been done in USA and it has been noted that the phenomenology sometimes varies across cultures, i.e. “tunnels are found mainly in Buddhist and Christian NDEs and not everyone has the same series of factors. However there does appear to be a core of typical factors, as outlined by Ring (1980) and since it is a deeply personal experience it seems unrealistic to expect a totally uniform account. Overall, the assumption of an afterlife does not in anyway explain what is going on during an NDE or what the cause of the event is. Psychological theories of NDE DEPERSONALISATION: During a frightening and potentially dangerous event, humans are known to experience depersonalisation where they will detach themselves from the unpleasant experience by abandoning their sense of personal identity and replacing the situation with a more pleasant and “dreamlike” scenario. The idea of depersonalisation and hence the NDE, at the point of death (or perceived death) is thought to be the reaction of the mind to the end of the “self” Noyes (1972). However, although it is true that depersonalisation does occur at some frightening experiences, this does not explain the common phenomenology of the NDE. Also, depersonalisation does not fit with reported experiences, i.e.. “dreamlike “ states are not associated with NDEs at all and Irwin (1999) points out that the NDE is taken to be a deeply personal event. In fact, NDErs describe it as being “very real” and a state of hyper-alertness is common. DISSOCIATION: Similarly, it has been proposed that the NDE is an example of dissociation where the individual withdraws from unwanted feelings and experiences such as fear of death so as not to bear the emotional impact. Since dissociation is thought to be a psychological defence mechanism to avoid intrusive and unwanted feelings, it has been proposed that the NDE is an instinctive response to an undesirable situation i.e. impending death; the NDE will therefore be more common in people who have suffered childhood trauma and hence have more of a tendency to use this mechanism. There has been some speculation over whether incidences of childhood trauma are more prevalent in NDErs than non-experiencers but results have been inconclusive, Greyson (1999). It should be noted that even if assuming that NDErs have had a tendency to dissociate, there is no reason to think that the NDE is the same kind of experience especially since the NDE is believed by those involved to be very real and are experienced with the ego intact; individuals who suffer recurrent, chronic dissociative disorders do not match the typical conditions of NDErs, Atwater (2000). REMEMBERING THE BIRTH EXPERIENCE : Proponents of this theory (Sagan 1979) argue that the NDE can be explained in terms of remembering our own birth experiences; the “tunnel” is reminiscent of the birth canal and the “light” is merely the light of the world into which we are born. It is further suggested that a reported experience of meeting beings of light etc are representations of the surgical staff and loving parents. This theory has been heavily criticised on a number of points; birth is a stressful series of pushes and the infant is compacted and squeezed during the event where as NDErs report peacefully floating or being pulled along more spacious, vacuous tunnel. Also, new-borns come in to the world with eyes closed and not facing forward and without the capacity to store this experience as the brain has yet to form fully, Becker (1982). In a study of NDErs who reported the “tunnel” element of their experience, it was found that there was no statistically significant difference in accounts of those born vaginally compared to those born via caesarean section, Blackmore (1983). Thus, there is very little other than speculation to support this theory of the NDE phenomenon. HALLUCINATIONS: Another commonly proposed theory of NDE causation is that of hallucinogenic drugs such as LSD, or medicinally used morphine. Also, naturally occurring endorphins are thought to explain the euphoric feelings and “beings of light” etc. However, there is little support for these claims as a important factor in the NDE explanation. Although some aspects of the NDE may be experienced while a person is under the influence of a drug, the hallucinations that result tend not to be of the same nature as the NDE. Drug induced hallucinations tend to be reported as fuzzy and confusing experiences – unlike the vivid and realistic accounts of NDE, furthermore drug users do not maintain a belief that what they experienced (even if similar to NDE factors) was real where as NDErs do. Greyson (2000) points out that many of the NDErs were not under the influence of drugs at all and still report the typical NDE. Also, it has been proposed in a study of death-bed visions (Osis and Haraldsson,1977) that drugs or metabolically induced states of delirium may act as an inhibitor of the NDE. With regards to natural endorphins that are thought to rush through the dying body to reduce pain and shock, there is nothing in research so far to suggest that any more endorphins are produced at death than at any other stressful event, Atwater (2000). However, the occasions where the death is only perceived and there is no real threat to the individual who claims and NDE, could be taken to be such a stressful situation. Although it appears that the role of drugs is sketchy in the NDE, there has been vast research in to one particular drug which has been a tremendous challenge to proponents of the NDE as more than a physical experience; the drug is ketamine. Ketamine is a psychoactive drug -mainly used as an anaesthetic- has been known to cause short –term hallucinogenic side effects which result in experiences remarkably similar to the NDE: the “tunnel”, the “light” and some kind of communion with God is often reported by patients under its influence. Furthermore, ketamine acts as an inhibitor of a certain neuro-transmitter involved in memory which results in sensations of the outside environment to be blocked out and thus only past memories are available to consciousness, this thought to be the reason why individuals using ketamine report a “life review”. As with NDErs, those who experienced the ketamine effects, maintained that they had experienced something real i.e. “the tunnel that took them to the light where they met God” was a real experience ( not attributed to ketamine) and not merely a real hallucination, Jansen (1997) . There is a significant statistical difference though in that 30% of ketamine induced experiencers maintain it was all real, almost 100% of NDErs maintain the realness of their account. As intriguing as the ketamine studies are in explaining the NDE, it runs in to further problems when we consider that many of the NDErs have their experience without being under the influence of ketamine or any other drug. Perhaps there is room to speculate that in these cases the body could be producing its own natural ketamine–like chemical, that has yet to be recorded? While ketamine can produce startling effects of NDE like reports, those involved do not show the profound after effects (i.e. life changes including beliefs and habits) that non- ketamine NDErs show; also Strassman (1997) points out that ketamine induced experiences tend to be more fearful than pleasant and Fenwick (1997) notes that ketamine gives rise to an unreal quality of experience in many. The effects ok ketamine are a result of temporary changes in cerebral function and it is interesting to note that during the NDE, the brain is altered functionally, structurally and chemically, Atwater (2000). DREAMS: The proposal that NDEs are dreams is highly speculative and has many flaws in that that dreams tend to be non cohesive, surreal and are rarely remembered vividly – entirely different from the NDE which is recalled as being coherent, meaningful and a real experience. The correlates of the NDE also put doubt on the dream idea since the NDE appears consistently at a specific time i.e. death or perceived death and not at random with the consistent elements seemingly cross cultural. The images in dreams tend to be of a more random nature. OXYGEN DEPRIVATION: It has been considered that hypoxia – a lack of oxygen to the brain- can induce temporal lobe seizures which can result in NDE like experiences, Sabom and Kreutziger (1982). The effects that have been reported are the panoramic “life review” but the memories do not share the same structure of those in the NDE – they appear to be random. Other sensations experienced in seizures are qualitatively different from an NDE and include auditory rather than visual imagery, Irwin, (1999). Eddell (1999) and many others purport that the NDE is nothing more than a result of severe oxygen deprivation, Anoxia. When the brain is severely deprived of oxygen, the experience of the “tunnel” is engendered. This is due to the disinhibition of cells which cause more firing of cells in the visual cortex which can give rise to tunnel vision and bright lights that seem to expand infinitely. In addition to these visual aspects, anoxic patients often report feeling a sense of floating and euphoria. Since anoxia is one of the most common features of a dying body (Rodin, 1980), there could be a high chance that dying, anoxic patients will report these NDE like effects. The proposition of anoxia as the key role in NDE is interesting as studies from different research lend support for this. Whinnery, (1990, 1997) examined the experiences of pilots who endured high speed acceleration when training particular manoeuvres. He found that not only was there a loss of consciousness due to anoxia when their blood flow to the brain suddenly reduced, but they reported feelings of euphoria, “tunnels”, bright lights, floating and even out-of –body experiences, they even reported “dreamlike” experiences of beautiful gardens and meeting relatives there. It should be noted however that the “relatives” encountered were still living and that there was a dreamlike quality to this experience; unlike the vivid alertness reported by NDErs. In 1982, Sabom produced research which suggested that anoxia was not a key feature in the occurrence of NDE. Sabom monitored the levels of oxygen and carbon dioxide in the blood of individuals during NDEs and found no difference between anoxic and non-anoxic individuals. Sabom's findings have been criticised however on methodological grounds as he measured the blood levels via easily accessible arteries that are not necessarily accurate in measuring blood in particular brain regions, Roberts (2001). Overall, anoxia can not be ruled out as having some role in the NDE but it can be rule out as a necessary causative factor as many of the reported NDEs occurred in people who were not suffering oxygen deprivation at all i.e. in perceived death that was not a genuine threat. The Dying Brain Hypothesis of NDE More recently, researchers have been proposing that the NDE is a side effect of dying; that as certain events happen during the death process, and the brain shuts down, it is highly likely that the person will have sensory experiences that account for the NDE. The Dying Brain Theory (DBT) was initially proposed by Dr Susan Blackmore (1993) and has been thoroughly discussed and hotly debated ever since. The NDE is accordingly explained via physiological and psychological events: anoxia; endorphin release; neurotransmitter activity and finally the breakdown of personal identity. Blackmore attributes the feelings of bliss and floating to endorphin release; the actions of certain neuro-transmitters affecting memory recall i.e. “life review" and the imagery of “tunnels”, “light” and humming or buzzing sounds are down to oxygen deprivation. The DBT proposes a combination of the theoretical effects of the natural dying process; but where Blackmore innovates her theory is in the explanation of the tunnel portion of the NDE and the out-of-body or autoscopy experience. The DBT suggests that the inhibitory cells in the visual cortex are extremely sensitive to oxygen depletion and so during hypoxia/anoxia these cells fail to act resulting in more neurological firing. The structural arrangement of the cells in the retina is important as the light receptors are in opulence in the centre of the retina in contrast to the periphery, hence one would expect that the increasing neural activity would result in the experience of an unusually bright light that grows and expands. It is further proposed that since the eyes are not actually seeing anything, then there would be no discomfort from this light. “Dissolution of the self” is then put forward as the final mechanism by which the OBE or viewing of oneself from above and the “timeless” quality is experienced. Blackmore argues that since the reconstruction is from memory of what was experienced, and the sense of reality was distorted during the NDE, she suggests that it is not surprising that NDErs recount an OBE. She likens the construction to how we perceive ourselves in everyday memory recall- from a 3 rd person narrative which can be often experienced in dreams when we see ourselves from above. Furthermore, previous research suggests that people who dream in the 3 rd person and recall their dreams from a birds-eye view have a tendency to experience more OBEs than others who do not (Irwin, 1986; Blackmore,1987). Blackmore's theory is compelling and can account for a great deal of the NDE, but only where it is known that oxygen deprivation was suffered. As Dr Kenneth Ring (1995) points out; The Dying Brain Theory associates the state of the physical brain at the onset of a potential NDE and can provide access to such an event but this does not necessarily give an explanation of the actual experience in every or maybe all cases. Conclusion Most of the research discussed only examines specific elements of NDE and not the entire experience; assuming that the whole is grater than sum of its parts, researching this phenomenon has led to many problems for researchers in establishing a satisfactorily parsimonious, explanation. Not all theories are equally plausible , although some (such as the Dying Brain Theory) do provide interesting new ways of discussing the phenomenology and implications of the process of physical death. Furthermore, the discussion and debate over the NDE provides raw material for new insights in to our own mortality and capacity for life. Perhaps more stringent methods are required in analysing “circumstantial evidence” . Such information is purported to take a more supernatural form where, NDErs reporting information that they could not have known through the known senses afterwards; i.e. Some individuals claim they saw the doctors operate whilst they were clinically dead and others believe that they have brought back ideas for technology and medicine via some divine instruction. Incidentally some advances in a form of light therapy were patented following a doctors own NDE. There is also a need for a more definite standardisation of terms such as death, death state, near-death state etc, but this ambiguity does not make the experience of those changed dramatically by the NDE phenomenon any less important or real. The after effects of the NDE are definitely real and even measurable by others and is a world wide issue that has prevailed over time. Professional researchers must bear a responsibility to mankind to further understand and accept the NDE as a valid human experience; research into discovering the cause and effect of the NDE s provides an opportunity to better understand how the brain operates as a physical organ and to expand the current thinking of our own consciousness and its potential capacities that have perhaps lay underused and misunderstood by science for millennia. Until we expand our awareness and understanding of other, potentially related phenomenon, the answer to this age old mystery will remain as elusive as the experience itself. References Blackmore, S (1991): Near-Death Experiences: In or Out of the Body? Skeptical Enquirer,16 34-45 Blackmore, S (1998) : Experiences of Anoxia: Do Reflex Seizures resemble NDEs? Journal of Near-Death Studies, 17, 111-120 Osis, K and Haraldsson, E (1977) : At the hour of Death . Avon, New York Irwin, H.J (1994) : An Introduction to Parapsychology, 2 nd Edition . Macfarland and Co Inc publishers, North Carolina Kurtz, P (1994) : A Skeptics Handbook of Parapsychology . Prometheus Books, Buffalo. New York. Moody, R.A (1975) : Life after Life . Bantam Books, New York City. Moody, R.A (1990) : Life Before Life . MacMillan London Limited Morse, I; Venecia,D: Milstein,J (1989) : Near-Death Experiences, a neurophysiological explanatory model. Journal of Near-Death Studies, 8 45-53 Morse, M; Perry, P. (1990) : Closer to the Light: Learning from the NDEs of Children . Villard Books, New York City. Ring, R; groome, D. (2001) : Parapsychology: The Science of unusual Experience . Arnold, London co-published in USA by Oxford University Press. New York. Sabom, MB (1982) : Recollections of Death . Corgi books, Transworld Publishers Ltd, London Tart, C. T (1978): A Psychophysiological Study of out of body Experiences in a selected subject. Journal of the Society for Psychical Research, 62, 3-27. Websites: Near-Death Experiences: www.mindspring.com/~scottr/end.html Near-death information ( International Association for Near-Death Studies) www.iands.org/web.html Near-Death information www.near-death.com © kittieklaw.com 2004 |
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