A near-death experience (NDE) is a profound personal experience associated with death or impending death, which researchers describe as having similar characteristics. When positive, which the great majority are, [1] such experiences may encompass a variety of sensations including detachment from the body, feelings of levitation, total serenity, security, warmth, joy, the experience of absolute dissolution, review of major life events, the presence of a light, and seeing dead relatives. When negative, such experiences may include sensations of anguish, distress, a void, devastation, and seeing hellish imagery. [1] [2] [3]
NDEs usually occur during reversible clinical death. Explanations for NDEs vary from scientific to religious. Neuroscience research hypothesizes that an NDE is a subjective phenomenon resulting from "disturbed bodily multisensory integration" that occurs during life-threatening events. [4] Some transcendental and religious beliefs about an afterlife include descriptions similar to NDEs. [2] [5] [6] [7] [8]
The equivalent French term expérience de mort imminente ("experience of imminent death") was proposed by French psychologist and epistemologist Victor Egger as a result of discussions in the 1890s among philosophers and psychologists concerning climbers' stories of the panoramic life review during falls. [9] [10]
In 1892, a series of subjective observations by workers falling from scaffolds, soldiers who suffered injuries, climbers who had fallen from heights and other individuals who had come close to death such as in near drownings and accidents was reported by Albert Heim. This was also the first time the phenomenon was described as a clinical syndrome. [11]
In 1968, Celia Green published an analysis of 400 first-hand accounts of out-of-body experiences. [12] This represented the first attempt to provide a taxonomy of such experiences, viewed simply as anomalous perceptual experiences or hallucinations.
In 1969, Swiss-American psychiatrist and pioneer in near-death studies Elisabeth Kübler-Ross published her well-known book On Death and Dying: What the Dying Have to Teach Doctors, Nurses, Clergy, and Their Own Families. [13]
The term "near-death experience" was used by John C. Lilly in 1972. [14] The term was popularized in 1975 by the work of psychiatrist Raymond Moody, who used it as an umbrella term for out-of-body experiences (OBEs), the "panoramic life review", the Light, the tunnel, or the border. [11]
Researchers have identified the common elements that define near-death experiences. [6] Bruce Greyson argues that the general features of the experience include impressions of being outside one's physical body, visions of deceased relatives and religious figures, and transcendence of egotic and spatiotemporal boundaries. [17] Many common elements have been reported, although the person's interpretation of these events often corresponds with the cultural, philosophical, or religious beliefs of the person experiencing it. For example, in the US, where 46% of the population believes in guardian angels, the Light will often be identified as angels or deceased loved ones (or will be unidentified), while Hindus will often identify them as messengers of the god of death. [18] [19]
Common traits that have been reported by NDErs are:
Note that an OBE may be part of an NDE, but can happen in instances other than when a person is about to die, such as fainting, deep sleep, and alcohol or drug use. [25]
A 1975 study conducted by psychiatrist Raymond Moody on around 150 patients who all claimed to have witnessed an NDE stated that such an experience has nine steps.
The steps are: [25]
Moody also explained how not every NDE will have each and every one of these steps, and how it could be different for each experience.
Moody describes the correct approach to an NDE patient is to "Ask, Listen, Validate, Educate, and Refer". [25] Due to the potential confusion or shock attributed to those who experience near-death experiences, it is important to treat them in a calm and understanding way right after their return from the NDE.
Kenneth Ring (1980) subdivided the NDE on a five-stage continuum, using Moody's nine step experiment as inspiration. The subdivisions were: [26]
The final stage is the person being resuscitated. [27]
Charlotte Martial, a neuropsychologist from the University of Liège and the University Hospital of Liège who led a team that investigated 154 NDE cases, concluded that there is not a fixed sequence of events. [28] Dr. Yvonne Kason classified near-death experiences into three types: "Out-of-Body", "Mystical" or "White-Light", and "Distressing". [29]
Kenneth Ring states that NDEs experienced following attempted suicides are statistically no more unpleasant than NDEs resulting from other situations. [30]
In one series of NDEs, 22% occurred during general anesthesia. [31]
Bruce Greyson found that NDEs had a lack of precision in diagnosis, so he created a questionnaire for those who had experienced NDE composed of 80 characteristics to study common effects, mechanisms, sensations and reactions. [32] Greyson replaced that questionnaire in 1983 with an exemplary scale for researchers to use. [32]
Component and question | Weighted response |
---|---|
Did time seem to speed up? | 2 = Everything seemed to be happening all at once 1 = Time seemed to go faster than usual 0 = Neither |
Were your thoughts sped up? | 2 = Incredibly fast 1 = Faster than usual 0 = Neither |
Did scenes from your past come back to you? | 2 = Past flashed before me, out of my control 1 = Remembered many past events 0 = Neither |
Did you suddenly seem to understand everything? | 2 = About the universe 1 = About myself or others 0 = Neither |
Did you have a feeling of peace or pleasantness? | 2 = Incredible peace or pleasantness 1 = Relief or calmness 0 = Neither |
Did you have a feeling of joy? | 2 = Incredible joy 1 = Happiness 0 = Neither |
Did you feel a sense of harmony or unity with the universe? | 2 = United, one with the world 1 = No longer in conflict with nature 0 = Neither |
Did you see or feel surrounded by a brilliant light? | 2 = Light clearly of mystical or other-worldly origin 1 = Unusually bright light 0 = Neither |
Were your senses more vivid than usual? | 2 = Incredibly more so 1 = More so than usual 0 = Neither |
Did you seem to be aware of things going on elsewhere, as if by ESP? | 2 = Yes, and facts later corroborated 1 = Yes, but facts not yet corroborated 0 = Neither |
Did scenes from the future come to you? | 2 = From the world's future 1 = From personal future 0 = Neither |
Did you feel separated from your physical body? | 2 = Clearly left the body and existed outside it 1 = Lost awareness of the body 0 = Neither |
Did you seem to enter some other, unearthly world? | 2 = Clearly mystical or unearthly realm 1 = Unfamiliar, strange place 0 = Neither |
Did you seem to encounter a mystical being or presence? | 2 = Definite being, or voice clearly of mystical or other-worldly origin 1 = Unidentifiable voice 0 = Neither |
Did you see deceased spirits or religious figures? | 2 = Saw them 1 = Sensed their presence 0 = Neither |
Did you come to a border or point of no return? | 2 = A barrier I was not permitted to cross, or "sent back" to life involuntarily 1 = A conscious decision to "return" to life 0 = Neither |
According to the Rasch Rating Scale Model, Greyson's 16 multiple-choice questionnaire can be universally applied to all NDEs. It yields the same results no matter the age and gender of the victim, the intensity of the experience, or how much time elapsed between taking the survey and the NDE itself. With the results ranging from 0 to 32, the average score is 15 and the one standard deviation below the mean is 7. A score below 7 is considered a "subtle" NDE; a score between 7 and 21 is a "deep" NDE; and a score 22 or above is a "profound" NDE. [33]
This scale has helped many researchers advance and enrich their discovery, most notably, Dr. Jeffrey Long. Long set out to discover the "reality" of NDEs mostly linked to cardiac arrest patients by using this scale and reviewing Near Death Experience Research Foundation studies. [34] His first line of evidence shows that 835 out of 1,122 people who had experienced NDE seemed to feel an increase in alertness and consciousness although studies proved no sign of electrical brain activity. [35] His second line of evidence studies the increase of accuracy developed by NDErs defining their resuscitation process with a 97.6% accuracy rate. [35] Long documented seven more lines of evidence that all point to realism in NDE experiences, yet not all of them verifiable or defined by today's medical advances and technology. [35] Having such an abnormally large amount (95.6% of 1,000 participants) of those who had experienced NDE proclaiming NDEs as real experiences, he concludes that although NDE are medically inexplicable, they are most probably a real phenomenon. [35]
NDEs are associated with changes in personality and outlook on life. [6] Ring has identified a consistent set of value and belief changes associated with people who have had an NDE. Among these changes, he found a greater appreciation for life, higher self-esteem, greater compassion for others, less concern for acquiring material wealth, a heightened sense of purpose and self-understanding, desire to learn, elevated spirituality, greater ecological sensitivity and planetary concern, a feeling of being more intuitive, [6] no longer worrying about death, and claiming to have witnessed an afterlife. [36] Although people who have had experienced NDEs become more spiritual, it does not mean they become necessarily more religious. [37]
However, not all after-effects are beneficial [38] and Greyson describes circumstances in which changes in attitudes and behavior can lead to psychosocial and psychospiritual problems. [39]
NDEs have been recorded since ancient times. [40] The oldest known medical report of near-death experiences was written by Pierre-Jean du Monchaux, an 18th-century French military doctor who described such a case in his book Anecdotes de Médecine. [41] Monchaux hypothesized that an influx of blood in the brain stimulated a strong feeling in the individual, and therefore caused a near-death experience. [41] In the 19th century a few studies moved beyond individual cases – one privately done by members of the Church of Jesus Christ of Latter-day Saints [42] and one in Switzerland. Up to 2005, 95% of world cultures are known to have made some mention of NDEs. [40]
In the U.S., an estimated nine million people have reported an NDE according to a 2011 study in Annals of the New York Academy of Sciences . Most of these near-death experiences resulted from serious injury affecting the body or brain. [43]
A number of more contemporary sources report the incidence of near death experiences as:
The current largest public repository of NDE accounts is maintained by the Near-Death Experience Research Foundation. [45] As of December 2024 the site lists more than 5,500 NDE stories which have been submitted through a standardized interface. These are organized into a database which allows users to search for specific characteristics of NDE experiences.
Bruce Greyson (psychiatrist), Kenneth Ring (psychologist), and Michael Sabom (cardiologist), helped to launch the field of near-death studies and introduced the study of near-death experiences to the academic setting. From 1975 to 2005, some 2,500 self-reported individuals in the US had been reviewed in retrospective studies of the phenomena, [40] with an additional 600 outside the US in the West, [40] and 70 in Asia. [40] Additionally, prospective studies had identified 270 individuals. Prospective studies review groups of individuals (e.g., selected emergency room patients) and then find who had an NDE during the study's time; such studies cost more to perform. [40] In all, close to 3,500 individual cases between 1975 and 2005 had been reviewed in one or another study. All these studies were carried out by some 55 researchers or teams of researchers. [40]
Melvin L. Morse, head of the Institute for the Scientific Study of Consciousness, and colleagues [22] [46] have investigated near-death experiences in a pediatric population. [47]
Researchers from the University of Michigan led by Jimo Borjigin discovered that areas of the brain responsible for interior visual experience were more active during cardiac arrest. According to the study, a sudden surge in brain activity at the time of cardiac arrest may be what causes people to perceive a bright white light when having a near-death experience. [48]
Following the rapid gamma activation locally within the posterior TPO zones, the long-range, global, and interhemispheric communications in gamma oscillations between the TPO zones and the prefrontal areas were activated in the dying brain, evidenced by the delayed activation of temporofrontal, parietofrontal, and Occipitofrontal networks when heart rate began to decline. Intriguingly, the long-range gamma connectivity between the posterior hot zones and the prefrontal areas at near-death was significantly higher over baseline only for those crossing the midline. Studies suggest that interhemispheric circuitry is important for memory recall, and gamma synchrony across the midlines is critical for learning, information integration, and perception. [48]
In 2001, Sam Parnia and colleagues published the results of a year-long study of cardiac arrest survivors that was conducted at Southampton General Hospital. 63 survivors were interviewed. They had been resuscitated after being clinically dead with no pulse, no respiration, and fixed dilated pupils. Parnia and colleagues investigated out-of-body experience claims by placing figures in areas where patients were likely to be resuscitated on suspended boards facing the ceiling, not visible from the floor. Four had experiences that, according to the study criteria, were NDEs but none of them experienced the out-of-body experience. Thus, they were not able to identify the figures. [49] [50] [51]
Psychologist Chris French wrote regarding the study "unfortunately, and somewhat atypically, none of the survivors in this sample experienced an out of body experience". [50]
In 2001, Pim van Lommel, a cardiologist from the Netherlands, and his team conducted a study on NDEs including 344 cardiac arrest patients who had been successfully resuscitated in 10 Dutch hospitals. Patients not reporting NDEs were used as controls for patients who did, and psychological (e.g., fear before cardiac arrest), demographic (e.g., age, sex), medical (e.g., more than one cardiopulmonary resuscitation (CPR)), and pharmacological data were compared between the two groups.
The work also included a longitudinal study where the two groups (those who had had an NDE and those who had not had one) were compared at two and eight years, for life changes. One patient had a conventional out of body experience. He reported being able to watch and recall events during the time of his cardiac arrest. His claims were confirmed by hospital personnel. "This did not appear consistent with hallucinatory or illusory experiences, as the recollections were compatible with real and verifiable rather than imagined events". [51] [52]
While at the University of Southampton, Parnia was the principal investigator of the AWARE Study, which was launched in 2008. [13] The study, which concluded in 2012, included 33 investigators across 15 medical centers in the UK, Austria and the US and tested consciousness, memories and awareness during cardiac arrest. The accuracy of claims of visual and auditory awareness was examined using specific tests. [53] One such test consisted of installing shelves, bearing a variety of images and facing the ceiling, hence not visible to hospital staff, in rooms where cardiac-arrest patients were more likely to occur. The results of the study were published in October 2014. [54] [55]
A review article analyzing the results reports that, out of 2,060 cardiac arrest events, 101 of 140 cardiac arrest survivors could complete the questionnaires. Of these 101 patients, 9% could be classified as near-death experiences. Two more patients (2% of those completing the questionnaires) described "seeing and hearing actual events related to the period of cardiac arrest". These two patients' cardiac arrests did not occur in areas equipped with ceiling shelves, hence no images could be used to objectively test for visual awareness claims. One of the two patients was too sick and the accuracy of her recount could not be verified. For the second patient, however, it was possible to verify the accuracy of the experience and to show that awareness occurred paradoxically some minutes after the heart stopped, at a time when "the brain ordinarily stops functioning and cortical activity becomes isoelectric (i.e., without any discernible electric activity)." The experience was not compatible with an illusion, imaginary event or hallucination since visual (other than of ceiling shelves' images) and auditory awareness could be corroborated. [51]
As of May 2016 [update] , a posting at the UK Clinical Trials Gateway website described plans for AWARE II, a two-year multicenter observational study of 900–1,500 patients experiencing cardiac arrest, which said that subject recruitment had started on 1 August 2014 and that the scheduled end date was 31 May 2017. [56] The study was extended, continuing until 2020. [57] In 2019, a report of a condensed version of the study with 465 patients was released. Only one patient remembered the auditory stimuli while none remembered the visual. [58]
A three-year longitudinal study has revealed that some Buddhist meditation practitioners are able to willfully induce near-death experiences at a pre-planned point in time. Unlike traditional NDEs, participants were consciously aware of experiencing the meditation-induced NDE and retained control over its content and duration. [59] The Dalai Lama has also asserted that experienced meditators can deliberately induce the NDE state during meditation, being able to recognize and sustain it. [60]
In a 2005 review article, psychologist Chris French [50] categorized models that try to explain NDEs into three broad groups which "are not distinct and independent, but instead show considerable overlap": spiritual (or transcendental), psychological, and physiological.
French summarizes this model by saying: "the most popular interpretation is that the NDE is exactly what it appears to be to the person having the experience". [50] The NDE would represent evidence of the immaterial existence of a soul or mind, which leaves the body upon death, and provides information about an immaterial world where the soul journeys after death. [50]
According to Greyson, [11] some NDE phenomena cannot be easily explained with our current knowledge of human physiology and psychology. For instance, at a time when they were unconscious, patients could accurately describe events "from an out-of-body spatial perspective". In two different studies of patients who had survived a cardiac arrest, those who had reported leaving their bodies could describe accurately their resuscitation procedures or unexpected events, whereas others "described incorrect equipment and procedures". [11] Sam Parnia also refers to two cardiac arrest studies and one deep hypothermic circulatory arrest study where patients reported visual and/or auditory awareness occurring when their brain function had ceased. These reports "were corroborated with actual and real events". [61] [51]
Five prospective studies have been carried out, to test the accuracy of out of body perceptions by placing "unusual targets in locations likely to be seen by persons having NDEs, such as in an upper corner of a room in the emergency department, the coronary care unit, or the intensive care unit of a hospital." Twelve patients reported leaving their bodies, but none could describe the hidden visual targets. Although this is a small sample, the failure of purported out-of-body experiencers to describe the hidden targets raises questions about the accuracy of the anecdotal reports described above. [11]
Psychologist James Alcock has described the afterlife claims of NDE researchers as pseudoscientific. Alcock has written the spiritual or transcendental interpretation "is based on belief in search of data rather than observation in search of explanation." [62] Chris French has noted that "the survivalist approach does not appear to generate clear and testable hypotheses. Because of the vagueness and imprecision of the survivalist account, it can be made to explain any possible set of findings and is therefore unfalsifiable and unscientific." [63]
French summarises the main psychological explanations, which include: the depersonalization, the expectancy and the dissociation models. [50]
A depersonalization model was proposed in the 1970s by professor of psychiatry Russell Noyes and clinical psychologist Roy Kletti, which suggested that the NDE is a form of depersonalization, experienced under emotional conditions such as life-threatening danger, potentially inescapable danger, and that the NDE can best be understood as a hallucination. [50] [64] [65] [66] [67] According to this model, those who face their impending death become detached from their surroundings and bodies, no longer feel emotions, and experience time distortions. [11]
This model suffers from a number of limitations to explain NDEs for subjects who do not experience a sensation of being out of their bodies; unlike NDEs, these hallucinatory experiences are dreamlike, unpleasant and characterized by "anxiety, panic and emptiness". [11] Also, during NDEs subjects remain very lucid of their identities, and their sense of identity is not changed, unlike those experiencing depersonalization. [11]
Another psychological theory is called the expectancy model. It has been suggested that although these experiences could appear very real, they had actually been constructed in the mind, either consciously or subconsciously, in response to the stress of an encounter with death (or perceived encounter with death), and did not correspond to a real event. In a way, they are similar to wish-fulfillment: because someone thought they were about to die, they experienced certain things in accordance with what they expected or wanted to occur. Imagining a heavenly place was, in effect, a way for them to soothe themselves through the stress of knowing that they were close to death. [50] Subjects use their own personal and cultural expectations to imagine a scenario that would protect them against an imminent threat to their lives. [11]
However, subjects' accounts often differed from their own "religious and personal expectations regarding death", which contradicts the hypothesis they may have imagined a scenario based on their cultural and personal background. [11]
Although the term NDE was first coined in 1975 and the experience first described then, recent descriptions of NDEs do not differ from those reported earlier than 1975. The only exception is the more frequent description of a tunnel. Hence, the fact that information about these experiences could be more easily obtained after 1975 had not influenced people's reports of the experiences. [11]
Another flaw of this model can be found in children's accounts of NDEs. These are similar to adults', despite children being less strongly affected by religious and cultural influences about death. [11]
The dissociation model proposes that NDE is a form of withdrawal to protect an individual from a stressful event. Under extreme circumstances, some people may detach from certain unwanted feelings in order to avoid experiencing the emotional impact and suffering associated with them. The person also detaches from one's immediate surroundings. [50]
The birth model suggests that near-death experiences could be a form of reliving the trauma of birth. Since a baby travels from the darkness of the womb to light and is greeted by the love and warmth of the nursing and medical staff, and so, it was proposed, the dying brain could be recreating the passage through a tunnel to light, warmth and affection. [50]
Reports of leaving the body through a tunnel are equally frequent among subjects who were born by cesarean section and natural birth. Also, newborns do not possess "the visual acuity, spatial stability of their visual images, mental alertness, and cortical coding capacity to register memories of the birth experience". [11]
A wide range of physiological theories of the NDE have been put forward, including those based upon cerebral hypoxia, anoxia, and hypercapnia; endorphins and other neurotransmitters; and abnormal activity in the temporal lobes. [50]
Neurobiological factors in the experience have been investigated by researchers in the field of medical science and psychiatry. [68] Among the researchers and commentators who tend to emphasize a naturalistic and neurological base for the experience is the British psychologist Susan Blackmore (1993), with her "dying brain hypothesis". [69]
According to Greyson, [11] multiple neuroanatomical models have been proposed, wherein NDEs have been hypothesized to originate from different anatomical areas of the brain, namely: the limbic system, the hippocampus, the left temporal lobe, Reissner's fiber in the central canal of the spinal cord, the prefrontal cortex, and the right temporal lobe.
Neuroscientists Olaf Blanke and Sebastian Dieguez (2009), [70] from the Ecole Polytechnique Fédérale de Lausanne , Switzerland, propose a brain-based model with two types of NDEs:
They suggest that damage to the bilateral occipital cortex may lead to visual features of NDEs such as seeing a tunnel or lights, and "damage to unilateral or bilateral temporal lobe structures such as the hippocampus and amygdala" may lead to emotional experiences, memory flashbacks or a life review. They concluded that future neuroscientific studies are likely to reveal the neuroanatomical basis of the NDE, which will lead to the demystification of the subject without needing paranormal explanations. [4]
French has written that the "temporal lobe is almost certain to be involved in NDEs, given that both damage to and direct cortical stimulation of this area are known to produce a number of experiences corresponding to those of the NDE, including OBEs, hallucinations, and memory flashbacks". [50]
Vanhaudenhuyse et al. (2009) reported that recent studies employing deep brain stimulation and neuroimaging have demonstrated that out-of-body experiences can result from a deficient multisensory integration at the temporal-parietal junction and that ongoing studies aim to further identify the functional neuroanatomy of near-death experiences by means of standardized EEG recordings. [71]
Blanke et al. [4] admit that their model remains speculative due to the lack of data. In addition, the reports of those who had the brain stimulation were almost nothing like OBEs reported by those who had NDEs, mainly characterized by a sense of elevation and (often limited) spatial awareness, while other characteristics of NDEs were absent. Anomalies such as seeing maps, half-bodies and duplications were also noted. [72] [73]
Likewise, Greyson [11] writes that although some, or any of the proposed neuroanatomical models may serve to explain NDEs and pathways through which they are expressed, they remain speculative at this stage, since they have not been tested in empirical studies. [11]
Some theories explain reported NDE experiences as resulting from drugs used during resuscitation (in the case of resuscitation-induced NDEs) ─ for example, ketamine ─ or from endogenous chemicals (neurotransmitters) that transmit signals between brain cells: [50]
According to Parnia, neurochemical models are not backed by data. This is true for "NMDA receptor activation, serotonin, and endorphin release" models. [51] Parnia writes that no data has been collected via thorough and careful experimentation to back "a possible causal relationship or even an association" between neurochemical agents and NDE experiences. [61]
The first formal neurobiological model for NDEs in 1989 included endorphins, neurotransmitters of the limbic system, the temporal lobe and other parts of the brain. [80] Extensions and variations of their model came from other scientists such as Louis Appleby (1989). [81]
Other authors suggest that all components of near-death experiences can be explained in their entirety via psychological or neurophysiological mechanisms, although the authors admit that these hypotheses have to be tested by science. [82]
Low oxygen levels in the blood (hypoxia or anoxia) have been hypothesized to induce hallucinations and hence possibly explain NDEs. [18] [50] This is because low oxygen levels characterize life-threatening situations and also the apparent similarities between NDEs and G-force-induced loss of consciousness (G-LOC) episodes.
These episodes are observed with fighter pilots experiencing very rapid and intense acceleration that results in lack of sufficient blood supply to the brain. Whinnery [83] studied almost 1000 cases and noted how the experiences often involved "tunnel vision and bright lights, floating sensations, automatic movement, autoscopy, OBEs, not wanting to be disturbed, paralysis, vivid dreamlets of beautiful places, pleasurable sensations, psychological alterations of euphoria and dissociation, inclusion of friends and family, inclusion of prior memories and thoughts, the experience being very memorable (when it can be remembered), confabulation, and a strong urge to understand the experience." [50] [83]
However, acceleration-induced hypoxia's primary characteristics are "rhythmic jerking of the limbs, compromised memory of events just prior to the onset of unconsciousness, tingling of extremities ..." that are not observed during NDEs. [18] Also, G-LOC episodes do not feature life reviews, mystical experiences and "long-lasting transformational aftereffects", although this may be due to the fact that subjects have no expectation of dying. [50]
Also, hypoxic hallucinations are characterized by "distress and agitation" and this is very different from near-death experiences, which subjects usually report as being pleasant. [11]
Some investigators have studied whether hypercarbia or higher than normal carbon dioxide levels, could explain the occurrence of NDEs. However, studies are difficult to interpret since NDEs have been observed both with increased levels as well as decreased levels of carbon dioxide, and other studies have observed NDEs when levels had not changed, but there is insufficient data on these factors. [18]
French said that at least some reports of NDEs might be based upon false memories. [84]
According to Engmann (2008), near-death experiences of people who are clinically dead are psychopathological symptoms caused by a severe malfunction of the brain resulting from the cessation of cerebral blood circulation. [85] An important question is whether it is possible to "translate" the bloomy experiences of the reanimated survivors into psychopathologically basic phenomena, e.g., acoasms (nonverbal auditory hallucinations), central narrowing of the visual field, autoscopia, visual hallucinations, activation of limbic and memory structures (according to Moody's stages). The symptoms suppose a primary affliction of the occipital and temporal cortices under clinical death. This basis could be congruent with the thesis of pathoclisis – the inclination of special parts of the brain to be the first to be damaged in case of disease, lack of oxygen, or malnutrition – established in 1922 by Cécile Vogt-Mugnier and Oskar Vogt. [86]
Professor of neurology Terence Hines (2003) claimed that near-death experiences are hallucinations caused by cerebral anoxia, drugs, or brain damage. [87]
Greyson has called into question the adequacy of the materialist, mind-brain identity model for explaining NDEs. [31] An NDE often involves vivid and complex mentation, sensation and memory-formation under circumstances of completely disabled brain function during general anesthesia, or near-complete cessation of cerebral blood flow and oxygen uptake during cardiac arrest. Materialist models predict that such conscious experiences should be impossible under these conditions. The mind-brain identity model of classic materialist psychology may need to be expanded to adequately explain an NDE.
Cardiac arrest is when the heart suddenly and unexpectedly stops beating. When the heart stops beating, blood cannot properly circulate around the body and the blood flow to the brain and other organs is decreased. When the brain does not receive enough blood, this can cause a person to lose consciousness and brain cells can start to die due to lack of oxygen. Coma and persistent vegetative state may result from cardiac arrest. Cardiac arrest is also identified by a lack of central pulses and abnormal or absent breathing.
Cardiopulmonary resuscitation (CPR) is an emergency procedure consisting of chest compressions often combined with artificial ventilation, or mouth to mouth in an effort to manually preserve intact brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person who is in cardiac arrest. It is recommended for those who are unresponsive with no breathing or abnormal breathing, for example, agonal respirations.
Clinical death is the medical term for cessation of blood circulation and breathing, the two criteria necessary to sustain the lives of human beings and of many other organisms. It occurs when the heart stops beating in a regular rhythm, a condition called cardiac arrest. The term is also sometimes used in resuscitation research.
An out-of-body experience is a phenomenon in which a person perceives the world as if from a location outside their physical body. An OBE is a form of autoscopy, although this term is more commonly used to refer to the pathological condition of seeing a second self, or doppelgänger.
An altered state of consciousness (ASC), also called an altered state of mind, altered mental status (AMS) or mind alteration, is any condition which is significantly different from a normal waking state. It describes induced changes in one's mental state, almost always temporary. A synonymous phrase is "altered state of awareness".
Raymond A. Moody Jr. is an American philosopher, psychiatrist, physician and author, most widely known for his books about afterlife and near-death experiences (NDE), a term that he coined in 1975 in his best-selling book Life After Life. His research explores personal accounts of subjective phenomena encountered in near-death experiences, particularly those of people who have apparently died but been resuscitated. He has widely published his views on what he terms near-death-experience psychology.
Near-death studies is a field of psychology and psychiatry that studies the physiology, phenomenology and after-effects of the near-death experience (NDE). The field was originally associated with a distinct group of North American researchers that followed up on the initial work of Raymond Moody, and who later established the International Association for Near-Death Studies (IANDS) and the Journal of Near-Death Studies. Since then the field has expanded, and now includes contributions from a wide range of researchers and commentators worldwide. Research on near-death experiences is mainly limited to the disciplines of medicine, psychology and psychiatry.
Deep hypothermic circulatory arrest (DHCA) is a surgical technique in which the temperature of the body falls significantly and blood circulation is stopped for up to one hour. It is used when blood circulation to the brain must be stopped because of delicate surgery within the brain, or because of surgery on large blood vessels that lead to or from the brain. DHCA is used to provide a better visual field during surgery due to the cessation of blood flow. DHCA is a form of carefully managed clinical death in which heartbeat and all brain activity cease.
Charles Bruce Greyson is an American psychiatrist and near-death experience researcher. During his research of near-death experiences, known as near-death studies, he has documented many accounts of near-death experiences, and has written many journal articles, as well as participated in media interviews on the subject, playing a crucial role in inviting broader cross-disciplinary scientific inquiry to the field.
Pam Reynolds Lowery, from Atlanta, Georgia, was an American singer-songwriter. In 1991, at the age of 35, she stated that she had a near-death experience (NDE) during a brain operation performed by Robert F. Spetzler at the Barrow Neurological Institute in Phoenix, Arizona. Reynolds was under close medical monitoring during the entire operation. During part of the operation she had no brain-wave activity and no blood flowing in her brain, which rendered her clinically dead. She claimed to have made several observations during the procedure which medical personnel reported to be accurate.
Targeted temperature management (TTM) previously known as therapeutic hypothermia or protective hypothermia is an active treatment that tries to achieve and maintain a specific body temperature in a person for a specific duration of time in an effort to improve health outcomes during recovery after a period of stopped blood flow to the brain. This is done in an attempt to reduce the risk of tissue injury following lack of blood flow. Periods of poor blood flow may be due to cardiac arrest or the blockage of an artery by a clot as in the case of a stroke.
The Arctic Sun Temperature Management System is a non-invasive targeted temperature management system. It modulates patient temperature by circulating chilled water in pads directly adhered to the patient's skin. Using varying water temperatures and a computer algorithm, a patient's body temperature can be better controlled. It is produced by Medivance, Inc. of Louisville, Colorado.
Lazarus syndrome, also known as autoresuscitation after failed cardiopulmonary resuscitation, is the spontaneous return of a normal cardiac rhythm after failed attempts at resuscitation. It is also used to refer to the spontaneous return of cardiac activity after the patient has been pronounced dead. Its occurrence has been noted in medical literature at least 38 times since 1982. It takes its name from Lazarus who, according to the New Testament, was raised from the dead by Jesus.
Pim van Lommel is a Dutch author and researcher in the field of near-death studies.
Peter Brooke Cadogan Fenwick was a British neuropsychiatrist and neurophysiologist who is known for his studies of epilepsy and end-of-life phenomena.
Sam Parnia is a British associate professor of medicine at the NYU Langone Medical Center, where he is also director of research into cardiopulmonary resuscitation. In the United Kingdom, he is director of the Human Consciousness Project at the University of Southampton. Parnia is known for his work on near-death experiences and cardiopulmonary resuscitation.
Deathbed phenomena refers to a range of experiences reported by people who are dying. There are many examples of deathbed phenomena in both non-fiction and fictional literature, which suggests that these occurrences have been noted by cultures around the world for centuries, although scientific study of them is relatively recent. In scientific literature such experiences have been referred to as death-related sensory experiences (DRSE). Dying patients have reported to staff working in hospices they have experienced comforting visions.
Terminal lucidity is an unexpected return of consciousness, mental clarity or memory shortly before death in individuals with severe psychiatric or neurological disorders. It has been reported by physicians since the 19th century. Terminal lucidity is a narrower term than the phenomenon paradoxical lucidity where return of mental clarity can occur anytime. However, as of 2024, terminal lucidity is not considered a medical term and there is no official consensus on the identifying characteristics.
Post-cardiac arrest syndrome (PCAS) is an inflammatory state of pathophysiology that can occur after a patient is resuscitated from a cardiac arrest. While in a state of cardiac arrest, the body experiences a unique state of global ischemia. This ischemia results in the accumulation of metabolic waste which instigate the production of inflammatory mediators. If return of spontaneous circulation (ROSC) is achieved after CPR, then circulation resumes, resulting in global reperfusion and the subsequent distribution of the ischemia products throughout the body. While PCAS has a unique cause and consequences, it can ultimately be thought of as type of global ischemia-reperfusion injury. The damage, and therefore prognosis, of PCAS generally depends on the length of the patient's ischemic period; therefore the severity of PCAS is not uniform across different patients.
The Human Consciousness Project is a professional organization, located at the University of Southampton, set up to study the nature of consciousness, the human brain and clinical death. The project is multidisciplinary and involves scientists and physicians worldwide. Sam Parnia serves as director of the project.
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: CS1 maint: multiple names: authors list (link)Scores on the NDE Scale can range from 0 to 32; the mean score of NDErs is 15; and a score of 7, one standard deviation below the mean, is generally used as a criterion for considering an experience to be an NDE (Greyson 1983). For the purpose of this study, we categorized NDEs by "depth," with NDE Scale scores less than one standard deviation below the mean considered "subtle," those less than one standard deviation above the mean considered "deep," and those greater than 1 standard deviation above the mean considered "profound."