Owing to a discussion with a friend, I recently had occasion to reread the van Lommel et al. paper published in 2001 in
Lancet detailing their prospective study of cardiac patients who had suffered cardiac arrest and were successfully resuscitated from clinical death. I had read that paper probably 10-12 years ago, and it seems to have been about the last thing I had read on the topic of NDEs. There have been several noteworthy studies and books published on NDEs in the interim, and I recently perused some of these.
In the process I came across a video of the 2014
Intelligence Squared debate on the topic. Team 1, arguing for the motion “Death is not final,” consisted of neurosurgeon Eben Alexander, whose academic appointments include Duke University Medical Center, UMass Medical School, Harvard Medical School and University of Virginia Medical School, and who had an extensive NDE in 2008 during a 7-day coma due to a severe case of case of bacterial meningitis, and Dr. Raymond Moody who coined the term “near-death experience” in 1975 in
Life After Life, which included the earliest qualitative study of this phenomenon. Arguing against the motion were CIT physics professor Sean Carroll and Yale neurology professor Steven Novella, apparently neither of whom seem to have any professional or personal connection to NDEs.
Although oozing civility, I found the debate disappointing. I thought both teams advanced certain poor or otherwise dubious arguments, oftentimes premised on assertions about metaphysics--despite the chairman Robert Rosenkranz and moderator John Donvan assuring us at the beginning that it would not be a “religious debate” but would rise to the level of science.
Dr. Alexander was first up, mostly using his opening statement to tell about his own NDE and the subsequent change in his beliefs. He got around to noting a few general facts about NDEs just before his time ran out.
So, before getting to my questions, I wish to review some of the easily discoverable information on NDEs.
An NDE is an event consisting of awareness or perception of various unusual phenomena, occurring most often (but not always) in the context of clinical death or life-threatening circumstances or injury, and for research purposes the elements of which are often identified and measured by the
Greyson NDE Scale. Of course, this fact itself raises the question as to why the basic elements of NDEs are so similar from person to person, regardless of culture. In contrast, people have an endless variety of dreams and hallucinations.
In the van Lommel et al. study of 344 consecutive patients who were resuscitated from clinical death, 62 (18%) subsequently reported some memory during the episode, with 41 of these describing elements commonly associated with NDEs, such as awareness of being dead, positive emotions, moving through a tunnel, meeting with deceased relatives, involvement in a life review, interacting with a bright light. The authors found that whether or not a patient had an NDE was not associated with the duration of cardiac arrest (presumably a proxy measure of degree of hypoxia) or unconsciousness, medications, fear of death before cardiac arrest, religious beliefs (or lack thereof) or education.
NDEs were transformative for those who had them. In follow-up questionnaires at 2 and 8 years, these people were more likely to report positive changes in beliefs and outlook such as an increased acceptance of others, being more empathetic and loving, having a sense of inner meaning of life, appreciation of ordinary things. As van Lommel and many others have pointed out, it's basically unheard-of for people to undergo a radical transformation in their outlook and beliefs about reality in response to a single hallucination or dream lasting a few minutes at most.
Dr. van Lommel et al. comment on the well-known fact that experiences that are superficially similar to NDEs can sometimes be induced by methods such as electrical stimulation of the temporal lobe, high blood levels of CO2 (hypercapnia or hypercarbia), cerebral hypoxia such as fighter pilots sometimes experience resulting in G-LOC, and certain hallucinogenic substances. Yet the authors also point out some of the ways that these experiences are distinct from NDEs:
These induced experiences can consist of unconsciousness, out-of-body experiences, and perception of light or flashes of recollection from the past. These recollections, however, consist of fragmented and random memories unlike the panoramic life-review that can occur in NDE. Further, transformational processes with changing life-insight and disappearance of fear of death are rarely reported after induced experiences.
http://www.pimvanlommel.nl/files/publicaties/Lancet artikel Pim van Lommel.pdf
In her
study Sartori found that patients who had hallucinations (which were clearly distinguishable from NDEs in various ways) due to large doses of sedatives or painkillers eventually acknowledged that their experience was an hallucination, whereas those who had NDEs remained adamant that their experience was real.
Likewise, the induced experiences, in the absence of life-threatening circumstances, do not consistently entail the awareness of being dead, which, except for “positive emotions,” was the most prevalent NDE element described by those in the van Lommel study. In NDE accounts, people often indicate that their awareness of being dead was arrived at by an inference based on factors such as the perception of leaving their bodies, or seeing, from an elevated position, a lifeless body below them that they subsequently recognized as their own.
Even disregarding other aspects of NDEs, such logical thought processes and the having and retention in memory of complex, coherent experiences during the severely compromised neurological states in which NDEs commonly occur confound explanation of these experiences as a mere physiological artifact. In a 2006 article, Dr. van Lommel, after explaining that “[m]onitoring of the electrical activity of the cortex (EEG) has shown that the first ischemic changes in the EEG are detected an average of 6.5 seconds from the onset of circulatory arrest, and with prolongation of the cerebral ischemia
always progression to isoelectricity occurs within 10 to 20 (mean 15) seconds,” elaborates this issue:
The paradoxical occurrence of heightened, lucid awareness and logical thought processes during a period of impaired cerebral perfusion raises particular perplexing questions for our current understanding of consciousness and its relation to brain function. A clear sensorium and complex perceptual processes during a period of apparent clinical death challenge the concept that consciousness is localized exclusively in the brain. Parnia et al. (2001) and Parnia and Fenwick (2002) write that the data from several NDE studies suggest that the NDE arises during unconsciousness, and this is a surprising conclusion, because when the brain is so dysfunctional that the patient is deeply comatose, the cerebral structures, which underpin subjective experience and memory, must be severely impaired. Complex experiences such as are reported in the NDE should not arise or be retained in memory. Such patients would be expected to have no subjective experience, as was the case in the vast majority of patients who survive cardiac arrest, or at best a confusional state if some brain function is retained. The fact that in a cardiac arrest loss of cortical function precedes the rapid loss of brainstem activity lends further support to this view. An alternative explanation would be that the observed experiences arise during the loss of, or on regaining consciousness. The transition from consciousness to unconsciousness is rapid, and appearing immediate to the subject. Experiences that occur during the recovery of consciousness are confusional, which these were not. In fact, memory is a very sensitive indicator of brain injury and the length of amnesia before and after unconsciousness is an indicator of the severity of the injury. Therefore, one should not expect that events that occur just prior to or just after loss of consciousness should be clearly recalled.
http://www.pimvanlommel.nl/files/publicaties/Near-Death Experience_Consciousness and the Brain.pdf
The
2001 Parnia et al. prospective study that van Lommel cites yielded too few people reporting NDEs for statistical comparison, but the authors note that there was little difference between the NDErs and control group in partial pressure of carbon dioxide, and that arterial partial pressure of oxygen was double in the NDE group than in the control. The fact that
NDEs cannot be attributed to hypoxia, anoxia or hypercarbia is further demonstrated by the fact that NDEs occasionally occur in the context of non-life-threatening illnesses and near-accidents.
