I used to shrug in disinterest when I would hear about stories about Near Death Experiences (NDEs) and other things along those lines. It wasn't because I didn't think it was possible - I did! It was more because I wasn't sure how we could ever objectively know whether it was true, or just hallucination. However, with serious scientific studies now being done on NDEs, like the AWARE project, combined with very noteworthy folks now claiming to have had NDEs and just with the sheer number of cases (in the millions!) that are now out there, I got interested. At this point, it seems like it would be blatantly unscientific not to consider what's going on here.
This post is about Eben Alexander - a "man of science" - who had his own NDE and consequently a complete about-face on how he previously viewed NDEs. I personally think it's a pretty remarkable story. Apparently, much of the public agrees, as it has been on most major news channels, many radio stations and all across the Internet. His book, Proof of Heaven, was also #1 on the New York Times best seller list.
The NDE itself wasn't a clincher in showing the experience had to happen independent of the brain. However, part of what made this story special was Eben Alexander's background. He is a respected neurosurgeon who taught at Harvard for 15+ years and has over 100 scientific publications and articles written in the field. He was also a "skeptic" and due to the paths life had taken him down, one who fell into disbelief of any kind of life beyond the one we currently know of. Like most doctors, he was familiar with NDE stories, but dismissed them as hallucination, at best. However, after having his own NDE, his views completely changed.
It's very obvious Dr. Alexander has put a lot of honest effort into trying to figure out what happened to him. In his attempt to try and understand what happened to him, he came up with 9 different scientific hypotheses, which he eventually concluded all fall short of explaining NDEs. He's now devoting his life to the study of this and other similar phenomenon related to exploring the mystery of consciousness.
Dr. Alexander remembered many rich details from the NDE, which I will let him tell in his own words in a few videos I will include in this post. The following 20/20 video is a nice summary of Dr. Alexander's NDE. To all the tough guys out there, tell me you weren't at least a little moved by the ending of that one. ;-)
Dr. Alexander's Near Death Experience was brought on by bacterial meningitis, which left him in a coma for 7 days. His brain was in a truly bad state of affairs. An MRI showed the entire surface of his neocortex was inflamed and covered in pus, a result of being under attack from the bacterial infection. The cerebrospinal fluid glucose level of a normal healthy person is around 80 milligrams per deciliter (mg/dl). A level of 20 mg/dl puts one in danger of imminent death. Dr. Alexander had a level of 1. This means the bacteria had eaten all the available glucose and were now munching on his neocortex. Cerebrospinal fluid is normally a clear watery substance. Even the slightest opacity in the the fluid would be an indication of infection. When they performed the spinal tap to check the condition of Dr Alexanders fluid, it didn't leak out like cerebrospinal normally would . It gushed out, due to the high pressure in his brain. On top of that, what gushed out was not fluid-like at all - it was pus. During his coma, the guttural groans and other primitive reflexes also began to diminish, indicating even the deepest, most primitive layer of his brain - the brain stem - was shutting down. At the beginning of the 7 days of coma, he had a 10% chance of survival, but would most likely remain in a vegetative state forever. By the end of the week, the doctors and family were ready to pull the plug. Miraculously, Eben came out of the coma and has had a full recovery. That, in itself, is a mystery, if not also, a miracle.
As I mentioned, we don't really know when his NDE happened during that time period. There was no veridical OBE component allowing us to time stamp and verify any part of the experience as objectively real. There were a couple events during his NDE when Dr Alexander felt he was connected with his family and "real events", but these are vague enough to leave most people unsure. In the meantime, this leaves skeptics open to claim it happened during a reboot of the brain as he came out of the coma. Here's the problem with that explanation, though. Patients who fall ill with bacterial meningitis, or similar conditions, do indeed end up going through a sort of reboot process. As the brain comes back online and the various areas start to communicate again, patients typically go through a very confused state of affairs, which is called ICU psychosis. Dr. Alexander remembers going through this and confirmed he was pretty far out of it, as to be expected. However, he also remembers his NDE, as a hyper-real, crystal-clear lucid experience, with near-prefect memory recall. Why would the brain be able to produce a hyper-real, crystal-clear lucid experience at an earlier time, during coma, when it was even more impaired? You wake up from a coma because the brain has presumably healed itself enough to regain "waking" consciousness, but it's still not a fully-functioning consciousness at that point in time. It is disconnected, to say the least, which is why one goes through ICU psychosis. So, how did he have an ultra-real, lucid experience when his brain was even more impaired than this?
A popular model of the brain that is starting to rise in popularity for attempting to explain phenomenon like the Near Death Experience, is the transmission/antenna model. (There are really two models - commonly called the transmission and filter models - with subtle differences, but I will speak loosely here as if they are the same, since I won't go into enough details for it to matter). Surprisingly, these ideas have been around for quite some time, first postulated by early psychologists like William James and F.W.H Meyers in late 1800s and early 1900s. The essential idea is that the brain does not produce consciousness, but rather is a receiver of consciousness. The popular analogy is that of a TV antenna, which is not the source of the TV program, but rather receives the broadcast signal. When scientists look at the brain lighting up under an fMRI and associate certain parts of the brain with particular mental functions, under these models, this would be viewed as correlation and not causation. There is a very distinct difference here. Also, even though most mainstream scientists would view brain activity as the cause of consciousness, there is currently no known theory that explains how the brain produces consciousness. That means there is no strong scientific basis for choosing one model (a brain-produces-consciousness model vs a brain-as-receiver-of-consciousness model) over the other. The only real reason is that one might fit better into the current worldview (materialism) than the other.
There is gathering evidence in support of the transmission and filter models. One recent study was done in the UK on psilocybin, or hallucinogenic mushrooms. Since psilocybin produces an intense conscious experience, one would assume the brain should be lighting up like a Christmas tree under an fMRI scanner. What they found was the exact opposite. Psilocybin actually inhibited blood flow to certain areas of the brain and less activity was seen overall on the fMRI. One explanation in line with the models above is that the brain acts as a filter, or reducing valve, in its role as a receiver of consciousness. As the filter is loosened, or deactivated, in this case by decreased blood flow, consciousness can expand and experience non-brain-induced states. Therefore, the brain normally acts to limit the totality of perceptions consciousness is able to experience, perhaps to not overwhelm and allow us to efficiently operate in the physical world. One can place this in accord with evolution, because it has obvious survival advantages. Anyhow, an NDE like Dr. Alexander's, where the brain is mostly offline, or completely offline, would just be an extreme case where the filter is torn down altogether. The AWARE study, which I discussed in an earlier post, could offer the most convincing and striking evidence for these models, as it could show that consciousness can operate completely independent of the brain. This may happen in the next few years.
As crazy as all that may sound, there are even ideas in physics that suggest consciousness may be an irreducible, or fundamental element, of reality. One such theory is Orchestrated Objective Reduction (Orch-OR) formulated by acclaimed mathematical physicist Sir Roger Penrose and his colleague, anesthesiologist, Stuart Hameroff. Rest assured, I will have a post on this topic at some point!
I think models along these lines have a higher potential of ultimately explaining NDEs, as opposed to using solely the kind of physiological explanations Michael Shermer mentioned in the above video. There are pilots on record who have had NDEs and say the g-machines can't come close to fully explaining what they experienced in their NDE, contrary to what Shermer says. Oxygen deprivation may be the most popular conventional explanation. But, oxygen deprivation leads to confusion and delirium, not the well structured, lucid thought process reported in NDEs. Another popular one is the drug Ketamine, often used in hospitals. But Ketamine usually leads to unpleasant experiences, not the extremely pleasant experiences reported in NDEs. Unfortunately, direct subject reports like these, which contradict the common physiological explanations, are too often ignored. There are other attempts at conventional explanations for the NDE, all of which currently fall short of explaining the phenomenon. It has also been shown that the NDE experience has consistent universal themes across all cultures, religions and age groups, making theories, such as cultural conditioning and expectation unlikely, as well.
Most of the common physiological explanations do, of course, share some similarities to the NDE phenomenon. When viewed under the filter model, they should. Again, one could say drugs like DMT and psilocybin loosen the filter (i.e brain), whereas an NDE tears down the filter altogether. Therefore, on a basic level, drug experiences, oxygen deprivation, etc., all share similarities with NDEs, but could never fully account for the entirety of the NDE experience, which is exactly the problem we see. It's also important to keep in mind the physiological explanations for an NDE are dependent upon having a functioning neocortex. More and more cases are coming out that strongly suggest these NDEs are happening during a time when the neocortex is either offline, or severely impaired.
Eben Alexander's nine hypotheses probably constitute one of the more exhaustive attempts to come up with a brain-based theory. This probably seemed like a natural first line of attack to a neurosurgeon like Dr. Alexander, but he found them all lacking in providing a full and consistent explanation of the NDE phenomenon. Much like consciousness, the Near Death Experience remains a profound mystery. Dr Alexander has, however, made the bold step of going with what starts to seem like the simplest hypothesis - perhaps, consciousness, or our soul, is eternal. Well, it sounds bold, perhaps taboo, but even worse, it sounds {shudder} spiritual. But, is it really all that different from the Orch-OR model of Penrose and Hameroff?
The following video is a full-length interview from the Skeptiko podcast by Alex Tsakiris, which goes into the details of the NDE itself in much greater detail.
Eben Alexander's Nine Hypotheses and Why He Says They Fail to Explain His NDE**
For those interested in the nitty, gritty, this section contains details on the 9 hypotheses Dr. Alexander came up with. His second book is supposed to cover them in much greater detail.
I have content from the book in quotes and my comments, if any, in italics.
(1) "A primitive brain-stem program to ease terminal pain and suffering. This did not explain the robust, richly interactive nature of the recollections." I would add the question of how a dying organism would have time to pass on genes to replicate this behavior.
(2) "The distorted recall of memories from deeper parts of the limbic system that have enough overlying brain to be relatively protected from the meningitic inflammation, which occurs mostly at the surface. This did not explain the robust, richly interactive nature of the recollection"
(3) "Endogenous glutamate blockade with excitotoxicity, mimicking the hallucinatory anesthetic, ketamine (occasionally used to explain NDEs in general). I occasionally saw the effects of ketamine used as an anesthetic during the earlier part of my neurosurgical career at Harvard Medical School. The hallucinatory state it induced was most chaotic and unpleasant, and bore no resemblance whatsoever to my experience in coma."
(4) "N,N-dimethyltryptamine (DMT) “dump” (from the pineal, or elsewhere in the brain). DMT, a naturally occurring serotonin agonist (specifically at the 5-HT1A, 5-HT2A and 5-HT2C receptors), causes vivid hallucinations and a dreamlike state. I am personally familiar with drug experiences related to serotonin agonist/antagonists (that is, LSD, mescaline) from my teen years in the early 1970s. I have had no personal experience with DMT but have seen patients under its influence. The rich ultra-reality would still require fairly intact auditory and visual neocortex as target regions in which to generate such a rich audiovisual experience as I had in coma. Prolonged coma due to bacterial meningitis had badly damaged my neocortex, which is where all of that serotonin from the raphe nuclei in the brainstem (or DMT, a serotonin agonist) would have had effects on visual/auditory experience. But my cortex was off, and the DMT would have had no place in the brain to act. The DMT hypothesis failed on the basis of the ultra-reality of the audiovisual experience, and lack of cortex on which to act." I would also add that listening to accounts of folks who have used Ahayuasca, which contains DMT, gives the distinct impression that the experience is not wholly similar to NDEs
(5) "Isolated preservation of cortical regions might have explained some of my experience, but were most unlikely, given the severity of my meningitis and its refractoriness to therapy for a week: peripheral white blood cell [WBC] count over 27,000 per mm3, 31 percent bands with toxic granulations, CSF WBC count over 4,300 per mm3, CSF glucose down to 1.0 mg/dl, CSF protein 1,340 mg/dl, diffuse meningeal involvement with associated brain abnormalities revealed on my enhanced CT scan, and neurological exams showing severe alterations in cortical function and dysfunction of extraocular motility, indicative of brain stem damage."
(6) "In an effort to explain the “ultra-reality” of the experience, I examined this hypothesis: Was it possible that networks of inhibitory neurons might have been predominantly affected, allowing for unusually high levels of activity among the excitatory neuronal networks to generate the apparent “ultra-reality” of my experience? Given the prolonged course of my poor neurological function (seven days) and the severity of my infection, it is unlikely that even deeper layers of the cortex were still functioning"
(7) "The thalamus, basal ganglia, and brainstem are deeper brain structures (“subcortical regions”) that some colleagues postulated might have contributed to the processing of such hyperreal experiences. In fact, none of those structures could play any such role without having at least some regions of the neocortex still intact. All agreed in the end that such subcortical structures alone could not have handled the intense neural calculations required for such a richly interactive experiential tapestry."
(8) "A 'Reboot Phenomenon' – reboot phenomenon”—a random dump of bizarre disjointed memories due to old memories in the damaged neocortex, which might occur on restarting the cortex into consciousness after a prolonged system-wide failure, as in my diffuse meningitis. Especially given the intricacies of my elaborate recollections, this seems most unlikely." Also, see my discussion on ICU psychosis above.
(9) "Unusual memory generation through an archaic visual pathway through the midbrain, prominently used in birds but only rarely identifiable in humans. It can be demonstrated in humans who are cortically blind, due to damaged occipital cortex. It provided no clue as to the ultra-reality I witnessed, and failed to explain the auditory-visual interleaving."
**All taken from Eben Alexander's book, Proof of Heaven
Life Beyond Death, Dr Eben Alexander
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