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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Near-death experience | 5/8 | https://en.wikipedia.org/wiki/Near-death_experience | reference | science, encyclopedia | 2026-05-05T04:18:06.795176+00:00 | kb-cron |
=== Awareness during resuscitation (AWARE) study === 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. 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. 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. As of May 2016, 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. The study was extended, continuing until 2020. 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. In November 2022, the full study was published.
== Explanatory models == In a 2005 review article, psychologist Chris French 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.
=== Spiritual or transcendental models === 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". 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. According to Greyson, 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". 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". 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.
==== Criticism ==== Neuroscientist Charlotte Martial states that there is a dearth of solid empirical evidence about theories of non-local consciousness, which is claimed by some authors. 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."
=== Psychological models === French summarises the main psychological explanations, which include the depersonalization, the expectancy and the dissociation models.
==== Depersonalization model ==== 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. According to this model, those who face their impending death become psychologically detached from their surroundings and bodies, no longer feel emotions, and experience time distortions. 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". Also, during NDEs subjects remain very lucid of their identities, and their sense of identity is not changed, unlike those experiencing depersonalization.