Back in 2014 I published three blog posts on a study that showed a surge of electrical activity in the brains of dying rats. (First post, second post, third post.)
The surge was suggested as a possible naturalistic explanation of the near-death experience. Some NDE researchers countered that the electrical surge was so extremely minute (too small to be detected by a standard EEG) that it could not account for the complexity of the subjective experience reported by patients.
Recently a reader sent me two more studies on same subject. The first article, "Asphyxia-activated corticocardiac signaling accelerates onset of cardiac arrest," was originally published in 2015. Its findings:
Asphyxia stimulates a robust and sustained increase of functional and effective cortical connectivity, an immediate increase in cortical release of a large set of neurotransmitters, and a delayed activation of corticocardiac functional and effective connectivity that persists until the onset of ventricular fibrillation.... These results demonstrate that asphyxia activates a brainstorm, which accelerates premature death of the heart and the brain.
The second article, "Neural Correlates of Consciousness at Near-Electrocerebral Silence in an Asphyxial Cardiac Arrest Model," appeared in April of 2017. It concludes:
In summary, we found asphyxial CA [= cardiac arrest] to induce a period of near-electrocerebral silence that was marked by hypersynchrony in the frontal lobes and increased power in the visual cortices, which suggests potential markers of consciousness.
The material in both cases gets very technical, as would be expected of articles written by and for neuroscientists.
My first reaction is that the electrical activity reported still seems to be extremely minimal and restricted to narrow bands of the electromagnetic spectrum. This would (I think) make it hard to account for the persistence of consciousness according to currently accepted models of brain functioning, which posit widespread "global" information processing. In addition, the surge is very brief, yet some NDEs take place considerably later and last longer (as estimated by patients' veridical observations).
These points were part of the rebuttal offered by Bruce Greyson, Edward F. Kelly, and W.J. Ross Dunseath after the earlier rat study was published:
[T]he activity observed following cardiac arrest represents a tiny fraction of the total neuroelectric power present just before arrest ..., and thus it is misleading to describe these rat brains as being “hyperaroused.” All that can be concluded is that activity of unknown functional significance occurred at a few places in the EEG frequency spectrum in the context of near-total obliteration of activity accompanying the waking state. The pertinent question here is not whether there is any brain electrical activity at all after cardiac arrest, but whether there is activity of the type currently thought to be necessary for conscious experience....
[M]any reports of near-death experiences include verifiable perceptions by the experiencer that are anchored to specific time periods far longer than 30 s after cardiac arrest, the duration of the electrical surge in this study.
There was also a response by Robert Mays, who, like Greyson et al., argued that the electrical activity post-cardiac arrest was too small to account for consciousness.
The original researchers responded forcefully to Greyson et al. in this letter.
I think the NDE researchers' objections would apply to the new studies also. But I'm no expert, and perhaps there is something new in these papers, so I'm putting them out there to see if anyone more knowledgeable than I am in matters of neuroscience would like to comment.
Haven't had a chance to read the post yet, Michael, but the high standard you set for titles has just soared to a new level.
Posted by: Bruce Siegel | May 15, 2017 at 08:14 PM
Also of potential interest to you, my article about the possibility of animals having near-death experiences.
http://weekinweird.com/2014/04/28/animals-near-death-experiences/
Posted by: Chris Savia | May 15, 2017 at 08:35 PM
If the brain=mind model has any validity, then brain states should match the level of awareness, because, according to the standard model, electrical activity in the brain produces consciousness.
After all, awareness *is* the brain state -apparantly.
In order to report a higher level of awareness, which many NDErs report, we should expect electrical activity across the brain to be at a level higher than normal, but instead what we have here, even in these so called 'surges', is still a minimal level of electrical activity, certainly not enough to form even minimal 'normal' awareness, never mind heightened awareness.
The recent experiments with Psilocybin (the active ingredient in magic mushrooms) has only confirmed this. Despite media reports to the contrary, stating that Psilocybin 'increases brain activity', in actuality, these hallucinogens only *decrease overall brain activity*.
However, decreased brain activity actually results in some of the most cogent, hyper aware states of consciousness ever experienced by the subject, in complete contradiction to the standard brain=mind model.
For the media misrepresentation of the recent Psilocybin studies, please visit Bernardo Kastrup's blog, where he discusses this in greater detail, and more convincingly than I ever could!
Regards,
Douglas
Posted by: Douglas | May 16, 2017 at 09:52 AM
Excellent and informative post as always, Michael!
There are three main things that come to mind that make the dying brain hypothesis for NDEs unworkable in my view:
1. Veridical information. If we accept that this has occurred, then materialism itself is defeated.
2. Consistency of experience. Skeptics try to deny that NDEs are alike, but there should be *no* consistency of experience at all. This includes both in the positive sense (experiencing the same things) and in the negative sense (not experiencing certain things. And I would argue that consistency of experience in the negative sense is even more important, since the overall lack of random dreamlike and hallucinatory content is very difficult to explain under the dying brain hypothesis. When it comes to dreams and tripping, we can experience almost anything and everything. NDErs don't.
3. Irrelevancy. Even if it is proved that one thing or multiple things can trigger an NDE, my response is: duh. The whole *point* of NDEs is that people can have an experience of death without really dying, so there would *have* to be triggers of some sort that do not necessitate death. Contrariwise, NDEs as a general phenomenon do not prove anything either. It is individual experiencers' testimony and NDEs in the context of other phenomena that have weight (or ought to have weight, IMO) in forming a belief system that includes an Afterlife.
I think the tough work actually begins when we accept that materialism is dead and buried (and has no Afterlife, heh heh). As our discussion about Flint implies, it is very difficult to put together the big picture of what's going on when we take seriously all of the phenomena that we have observed to date.
Posted by: Matt Rouge | May 16, 2017 at 09:39 PM
Here's the link:
http://www.bernardokastrup.com/search?q=psilocybin
Posted by: Roger Knights | May 17, 2017 at 04:49 AM
PS: Read Kastrup's threads starting from the bottom up, to match his chronology.
Posted by: Roger Knights | May 17, 2017 at 05:01 AM
Here's a piquant Kastrup quote:
Posted by: Roger Knights | May 17, 2017 at 05:24 AM
Kastrup quotes a paragraph from MP in this thread, which is critical of New Age-ism:
http://www.bernardokastrup.com/2012/05/fantasies-in-modern-age.html
Posted by: Roger Knights | May 17, 2017 at 05:34 AM
When I first became interested in NDEs, a compelling factor which influenced my thinking was the empirical evidence suggesting that no brain activity was corresponding to complex structured awareness. Now clearly anything which genuinely brings this notion into question does undermine, at least to some degree, this important line of evidence supporting the spiritual nature of near death experiences.
I have not read any of the technical papers supporting the claim that these electrical spikes in the brain are the likely cause of NDEs, but it is reasonable to be initially cautious of such claims (not necessarily the presence of electrical spikes during the death process, but their significance in relation to NDEs). This caution is warranted because NDEs clearly invoke strong emotions on both sides of the debate, and there has been plenty of evidence that sceptics, even the more educated ones, are very biased against the idea of NDEs having a non-materialist explanation, and will typically espouse arguments that reflect this strong bias. I guess ultimately the devil is in the details, and it is probably worth investing a bit of time closely examining the relevant technical papers. Having said this however, I think the bottom line might be that the relevance of the spikes will remain an open question for some time to come. At this stage it is unlikely that anyone can convincingly ascertain the true significance of these electrical spikes to NDEs.
As I have not read the papers yet, there is one point I am not quite clear on. It has been demonstrated in a number of cases that there is no detectable brain activity during NDEs, certainly the ones involving cardiac arrest cases. Is it the claim of these scientists that these spikes are likely present in such cases anyway but occurring too deep in the brain to be detected?
It is important to bear in mind however that just because something is theoretically possible (from the point of view of a limited knowledge perspective) does not mean it is probable. As always, opinions on this will depend on the background beliefs of the individual. Anyone who is a philosophical materialist will immediately seize on the slightest suggestion that a materialist explanation is possible (this is just stating the obvious of course). Speaking personally, I am an agnostic with regards to such things as the afterlife, but I am certainly not an agnostic regarding reductive materialism, which is demonstrably false (I can't possibly meaningfully quality that statement here, but hope to write a number of guest posts on this blog when I have chance, outlining some of the main reasons I know this to be the case). Despite the claims of certain individuals, there are currently no viable theories of consciousness (again another statement I can't meaningfully qualify here). Partly as a consequence of the above realizations, I do not personally believe that the brain produces consciousness, much less awareness during NDEs. It is important to acknowledge however that the brain undoubtedly influences the structure of conscious experience; hence the neural correlates of consciousness.
I am sure that any sceptic who heard someone continuing to claim that NDEs are genuine spiritual experiences despite this recent revelation of brain spikes in dying rats would take this as proof positive that believers will cling to their beliefs despite any evidence which works against their viewpoints. However this works both ways. It is unquestionably the case that all the evidence of veridical NDEs, and the absence of detectable brain activity during these episodes, has typically had absolutely no traction with sceptics. They are every bit as dogmatic as they claim believers of NDEs to be.
Again, to state the obvious, these brain spikes do not address the phenomenon of veridical NDEs, or at least cases where the NDEer could not possibly be aware of what they claimed to know, even given that they had some kind of limited brain functioning. These cases however constitute a relatively small minority of the total number of NDE cases, so I guess a sceptic could just simply discount such cases on this basis alone, simply reasoning that these minority cases are either instances of fraud or are simply due to some other more mundane explanation.
The bottom line is that from a believers point of view the ideal situation is to have a categorical black and white shut case of their being absolutely no brain activity during NDEs. This makes a materialistic explanation of NDEs very tricky indeed. However the reality is that this situation is not so black and white as one would like to hope for. But one should guard against the more extravagant claims of materialistic sceptics who are as good as suggesting that these electrical spikes are almost certainly the explanation for NDEs.
Posted by: Mark Green | May 17, 2017 at 07:50 AM
sorry if this is ot...what do you think of this??
https://link.springer.com/article/10.1007/s00426-017-0855-9
Posted by: davide | May 17, 2017 at 12:26 PM
Mark writes: "It is important to acknowledge however that the brain undoubtedly influences the structure of conscious experience; hence the neural correlates of consciousness."
"The bottom line is that from a believers point of view the ideal situation is to have a categorical black and white shut case of their being absolutely no brain activity during NDEs."
But if the brain necessarily influences the structure of consciousness then, surely, there has to be some kind of brain activity at some level for the conscious experience to be structured and recorded in memory when full consciousness re-emerges? Or am I missing something vital in the permutation?
Posted by: Julie Baxter | May 17, 2017 at 12:53 PM
People who have death bed visions and nearing death awareness are on the verge of dying. They are half here and half there. It is very common and it is written that about 60%+ of people in hospice have these visions. Something happens to the dying brain that triggers these visions.
I have read stories of people who have seen animals during these death bed visions and also in their near death experiences. I remember one in particular where the woman saw a golden retriever that she used to own. It is not that uncommon.
Most recently I read a charming story about a 35 year old woman with down syndrome who was dying (which they didn't know at the time) who saw her calico cat, Patches.
"We had a 35 year old with down syndrome and heart failure. She was doing very well, but one day her sister called in a panic. The pt had started talking about a cat being in her home. Her sister was sure she was hallucinating. So we went to see pt, and after talking to her it became clear that this was not just any cat. This was Patches, the pt's cat who she had grown up with and who had died 18 years earlier. This pt was insistent on us feeding patches, getting a litter box, etc. We mentioned to the family that we sometimes see this kind of thing at the end of life, but no one really took it seriously because the pt was doing so well. She died suddenly 5 days after Patches showed up." http://allnurses.com/general-nursing-discussion/deathbed-visions-updated-617087-page2.html?s=64af4daaf523f58b639bd44b44c5c385
We are all on our way to that place and our time here passes by quickly. It seems to be that it is irrelevant whether we believe it or not. It is universal and happens to everyone. Because of what I have read about terminal lucidity I believe we get it all back. All our memories and everything we have loved and lost on this side will be waiting for us in that Light.
Posted by: Art | May 17, 2017 at 02:47 PM
Julie wrote: 'But if the brain necessarily influences the structure of consciousness then, surely, there has to be some kind of brain activity at some level for the conscious experience to be structured and recorded in memory when full consciousness re-emerges? Or am I missing something vital in the permutation?'
Going back to Bernardo Kastrup's blog mentioned earlier, Bernardo has no problem with some brain correlation. In fact he says that his hypothesis 'kind of requires it'.
In his view, memories are not in themselves stored in the brain, but they are *retrieved* by the brain, so we should expect some neural activity when recalling memories. Upon regaining 'normal' consciousness from an NDE, the 'retrieval pathway', for want of a better phrase, is then encoded in the brain, not the memory itself.
This process is why it's technically incorrect to say that dementia destroys memories. I think it's more correct to say that dementia destroys *access* to memories.
This is why advanced dementia patients sometimes have moments of lucidity where they remember a small detail from 40 years ago, but a few seconds later and it's gone again, something I've witnessed on several occasions. For this reason, I think Bernardo's right. As to where memories are actually stored, that's still an open question. I have a feeling that they are not stored in the body at all - they belong to 'the field'.
Posted by: Douglas | May 18, 2017 at 09:43 AM
Semi-relevant; I own rats, who are very sweet, and have read articles about how rats show more empathy than a lot of humans, will fight snakes to save their babies, and are capable of feeling regret. Whatever is going on with this, I see no reason their brains and/or souls shouldn't work the same way humans' do.
"If having a soul means being able to feel love and loyalty and gratitude, then animals are better off than a lot of humans" - James Herriot.
Posted by: chel | May 18, 2017 at 11:16 AM
To relate it to reported near death experiences in humans they'd have to have evidence that the rats were having a near death experience, and dead rats can't report.
The only way to have any information about the internal experience of a living being is by their report of that experience. This should always be pointed out. And there is no way and there never will be any way to fact check the accuracy or truth or quality of that experience because the one experiencing it is the only one who knows anything about it, they are the one and only expert of their own experience.
Such neuroscience isn't science, it's ideological propaganda.
What a pointlessly sadistic experiment.
Posted by: Anthony McCarthy | May 18, 2017 at 05:58 PM
"Heaven goes by favor. If it went by merit, you would stay out and your dog would go in." - Mark Twain,
Posted by: Roger Knights | May 18, 2017 at 06:30 PM
Douglas wrote,
||In his view, memories are not in themselves stored in the brain, but they are *retrieved* by the brain, so we should expect some neural activity when recalling memories. Upon regaining 'normal' consciousness from an NDE, the 'retrieval pathway', for want of a better phrase, is then encoded in the brain, not the memory itself.||
That is cool. He and I have arrived at this conclusion independently. I think the science 100% backs this up. No specific memory location in the brain has been found to date.
||This process is why it's technically incorrect to say that dementia destroys memories. I think it's more correct to say that dementia destroys *access* to memories.||
Agreed. And the normal loss of memory over time is the same thing.
||As to where memories are actually stored, that's still an open question. I have a feeling that they are not stored in the body at all - they belong to 'the field'.||
Yes. I posit information by its very nature is indestructible, and the brain is simply accessing that information (both the "thing itself" and previous brain states).
Posted by: Matt Rouge | May 18, 2017 at 09:03 PM
"However, decreased brain activity actually results in some of the most cogent, hyper aware states of consciousness ever experienced by the subject, in complete contradiction to the standard brain=mind model."
But one can argue that this decreased brain activity consists in the inactivation of inhibitors, although there is still brain activity that generates the experience; I do not say it is so, but it can not be ruled out by the NDE researchers.
"Speaking personally, I am an agnostic with regards to such things as the afterlife, but I am certainly not an agnostic regarding reductive materialism, which is demonstrably false (I can't possibly meaningfully quality that statement here, but hope to write a number of guest posts on this blog when I have chance, outlining some of the main reasons I know this to be the case)."
The opposite happens to me: I think it is most likely that there is a personal afterlife due to some cases of OBEs, NDEs, apparitions of the deceased, mediumship and children who remember their past lives. While I agnostic about materialism because one could always expand its conception to include the afterlife as part of physical world. That field where the nervous system accesses memory could be physical for example.
Posted by: Juan | May 21, 2017 at 02:57 AM
Juan wrote,
||While I agnostic about materialism because one could always expand its conception to include the afterlife as part of physical world. That field where the nervous system accesses memory could be physical for example.||
We've talked about this a bit on here before, but I think one point bears repeating: materialism as it is currently conceived is what it is because its adherents are atheists who actively disbelieve in the Afterlife, psi, and so on. If proof of psi comes to be accepted by the establishment, I doubt that "materialism" will live on, including the name, as it will be a completely tainted "brand" at that point.
Posted by: Matt Rouge | May 21, 2017 at 10:40 AM
"We've talked about this a bit on here before, but I think one point bears repeating: materialism as it is currently conceived is what it is because its adherents are atheists who actively disbelieve in the Afterlife, psi, and so on."
So let them be called atheists, agnostics, mortalists or psi skeptics, but not materialists, because I use the term "materialism" as used in philosophy, and I believe it is the correct use.
Posted by: Juan | May 22, 2017 at 04:26 PM
Juan wrote “The opposite happens to me: I think it is most likely that there is a personal afterlife due to some cases of OBEs, NDEs, apparitions of the deceased, mediumship and children who remember their past lives.
Don’t get me wrong. I find some NDE accounts quite convincing, and on balance of probability think they are genuine spiritual experiences (which btw is perfectly compatible with being an agnostic).
“While I agnostic about materialism because one could always expand its conception to include the afterlife as part of physical world. That field where the nervous system accesses memory could be physical for example.”
I would go as far as saying that it is probably misleading to think of the afterlife as being strictly part of a different dimension or reality. But we know even this ‘physical’ world is not actually physical, much less the afterlife. It is all made up of energy, which you surely must agree is not a physical object. Of course it is possible to define the word ‘physical’ in a way in which it will encompass pure energy, but that would be pure semantics.
Posted by: Mark Green | May 23, 2017 at 04:16 PM
Julie wrote “But if the brain necessarily influences the structure of consciousness then, surely, there has to be some kind of brain activity at some level for the conscious experience to be structured and recorded in memory when full consciousness re-emerges? Or am I missing something vital in the permutation?”
It is clear that the brain does influence conscious experience as consciousness can be altered by various means, such as drugs, brain damage, etc. However some NDEers state that during the initial stages of the afterlife they continue to think and perceive much like a human does. This human level of perspective allegedly wears off in time however.
I don’t know the precise mechanism responsible for an NDEer remembering an experience which supposedly takes place outside the body. But my inability to specify the precise mechanism responsible does not make what I said contradictory. There are clearly plenty of logical possibilities to explain this.
Posted by: Mark Green | May 23, 2017 at 04:26 PM
Well, how long does that electrical surge, be it able to generate consciousness or not (most likely not), last for after cardiac arrest? In people its assumed that for about 20 to 30 seconds after cardiac arrest the brain is still working. That is widely acknowledged in NDE research which is why the results of the AWARE study were so important. Or is that electrical surge supposed to take place right after those 20-30 seconds?
Posted by: Jonas | May 23, 2017 at 07:28 PM
I find it interesting, in this context, to reflect on the fact that few if us even remember our dreams despite there being definite brain activity during their formation. Cells do not 'die' immediately when life ends. Therefore we must (surely?) consider the possibility of neuronal activity within the brain beyond the point of death - for whatever length of time.
Posted by: Julie Baxter | May 24, 2017 at 03:00 AM
Julie wrote: "Cells do not 'die' immediately when life ends. Therefore we must (surely?) consider the possibility of neuronal activity within the brain beyond the point of death - for whatever length of time."
I think you are missing a vital point here Julie. It is not so much whether cells are alive or dead but whether they are functioning. The physiology of cellular activity is quite well understood, and it is well established that cells do not function for very long without oxygen. The cells might be alive but if there is no neural activity then this suggests consciousness might not result from neural activity, would you agree? My TV might not be broken, but if it was switched off I would be quite mystified if there was picture and sound coming from it.
Posted by: Mark Green | May 26, 2017 at 10:03 AM