Light at the end of the tunnel

It has been a tough century for the soul. From its former role as the unquestionable master of our actions, emotions, memories, and behaviour it appears now as a wispy monarch without a kingdom, sustaining itself on the scraps left it by neuroscience, evolutionary biology, and genetics. And yet, if you've been watching the right places, you might have noticed that it has been making something of a determined comeback in the last decade, its fate tethered to the curiously rising star of Near Death Experience (NDE) research. A small group of psychologists have used NDEs to drive a wedge in the materialist conception of identity large enough for the disembodied self to squeeze itself into the scientific debate.

The bible for this school of thought, which continues to be more or less uncritically quoted as having scientifically established the incorporeal soul, is 2007's Irreducible Mind by Edward and Emily Kelly, with contributions from a handful of others. It is a good book to have in a fight, weighing in at 643 pages with another hundred in bibliography. There is no doubt at all that these are people who have painstakingly done their work in accumulating hundreds and thousands of atypical case studies over the past 30years. And we owe them thanks for that- nothing spurs science to figure things out to the next level of complexity quite like a puzzlement.

As the Tycho Brahes of unusual biological phenomena, there is nothing to fault them for here and much to admire. But Tycho had the splendid good sense to turn his astronomical data over to Kepler for interpretation, while the Kellys try to fill that role themselves, and this is where the problems start creeping in.

Put generally, the viewpoint of the authors is that psychology did itself a massive disservice when, early in the 20th century, it forsook the idea of a non-corporeal explanation of consciousness in favour of first behavioural psychology and then rigidly materialistic neural network theory. While they (at times begrudgingly) pay respect to the insights gained from these approaches, they nonetheless feel that the dominant position of materialism in the scientific establishment has pushed back by a century the progress that could have been had by studying psi-phenomena scientifically.

And there is much quoting of William James.

The authors have personally collected files on nearly a thousand instances of near death experiences and have come to the conclusion that this body of data represents unequivocal proof that an immaterial self exists. Their first argument is that the rich experiential cocktail of an NDE, with its bright lights and tunnels, out of body experiences, peaceful sense of serenity, vivid life memories and conversations with the deceased, is something far too complex to have been mixed by the mere brute matter of the brain. Keep that argument in mind – NDEs are too complex to be explained materially – we're going to need that later.

The authors then turn to review mainstream explanations for NDEs, curiously restricting themselves to 30 year old psychological explanations and a handful of more modern physiological ones, without paying much more than a nod to theories based in evolutionary biology. So we learn that oxygen deficiency can produce a pleasurable sense of leaving the body, and that increased carbon dioxide levels can produce tunnel vision with bright lights, spikes of access to past memories, and peaceful feelings of connection with God. Further, we find neurochemicals that produce a feeling of travel through a tunnel and communing with the divine, and that electrical stimulation of certain parts of the brain has produced out of body sensations. It's an impressive body of findings, made all the more so when you see that they don't quote any non-sympathetic study made after 1997.

What's more troubling than the omission of a decade of data, however, is the conclusions they draw from all of this. Instead of seeing that, hey, a lot of the very strange psychological occurrences characteristic of NDEs can be brought about by purely physical means, the lesson they take away is that no single chemical factor causes all of the characteristics by itself, and therefore physical explanations cannot and will not be able to explain NDE phenomena. They reject out of hand any attempt to explain NDEs as a combination of several of these chemical and biological factors working together, mocking them as "ad lib" and unscientific attempts to piece together a working theory after the fact.

Here's where their first argument comes in – one moment NDEs are described as too complex to be caused by the brain, and the next, when one tries to explain NDEs by piecing together discoveries from physiology and neurochemistry, the attempt is rejected as too complex! This is putting inquiry in something of a straightjacket, since if we aren't allowed to have complex or multi-faceted answers for complex phenomena, we aren't going to get very far. The only thing that will satisfy the authors is, apparently, if we find a batch of neurons somewhere that, all by itself, causes every NDE characteristic.

And that, as the authors well know, will never happen. Just look at the number of brain regions and chemicals involved in the motor response to a possible threat – a stimulus is sent to the lateral and then central nuclei of the amygdala, which then sends signals to neurons of the ventral tegmental area, which in turn release dopamine into the nucleus accumbens, which allows the activation of the pallidum, which allows for the initiation of movement by the cortex and brain stem. All of that to Just Start Moving – the demand that the entirety of the NDE response be localized to one region of the brain or one chemical in order to not be considered an ad lib fabrication is utterly unreasonable in light of all we have learned about the networking of synaptic systems. Mental events are incredibly complex, and to ask for a simple neural solution to them is to willfully ask the impossible in order to slip the immaterial soul in the silence that follows.

I hardly have words for what comes next. After rejecting a multiple neural region model for the NDE, they employ a multiple neural region model of consciousness in their very next argument. Near Death Experiences, they rightly point out, involve accessing memories, processing language, and crafting elaborate out of body scenes that incorporate pieces of the action around the patient. To do that requires a lot of mental coordination and activity – so how, they ask, is this possible for a brain which is basically dead, which shows minimal to no gamma activity of the type associated with conscious, memory-creating processes? And that's a good question, except for the fact that we have no data which shows that NDEs actually do occur during the time when the brain is flatlining.

We know for sure that there are many cases of NDE spectrum characteristics occurring when the brain is in full health – as when mountain climbers describe seeing their life flash before their eyes in the midst of falling. But since we don't know for sure when, say, a cardiac patient actually experiences their NDE mentally, the hypothesis that it is during the time when their brains show the least activity is little more than a convenient guess. Further, the idea that the brain is entirely without electrical activity during the closing moments of life is one which has come under increasing scrutiny as of late, particularly with Lakhmir Chawla's 2009 finding that the dying brain experiences a sometimes minutes-long spike in electrical activity just prior to death. Is it the right type of electrical activity to fit the effects we see in NDEs? More studies need to be done, but the fact that it is there at all shows that the brain still has a few tricks up its sleeve.

It's a trickiness which evolution has honed to a fine degree over the past few hundred million or so years. With the exception of the effectively immortal (but very humble about it) Turritopsis nutricula, the success of life on our planet is based upon the ability to die. For my genes to be passed on by my offspring, I have to relinquish my hold upon the resources that my descendants will need to survive. I have to die. Even as evolution has provided us with a thousand behavioral and neural adaptations to keep ourselves alive on a day-to-day basis, they are all shackled to a body which bounds gleefully deathwards. Recall the massive neural machinery set into motion when I just PERCEIVE a threat – is it so inconceivable that a brain which could develop that sort of response would also have a way of dealing with the imminent arrival of death itself which would draw on every trick in the mental playbook, from a comprehensive replaying of past memories to the creation of a soothing mental space populated by all the people we thought we'd never see again?

Could there not be an evolutionary advantage to throwing the dying body into a Xanadu of pleasantness when one is clearly past the ability to help one's self? Except for a brief sentence that precedes two pages of battle with 1980s Expectation Theory, the Kellys fail to acknowledge any physical model which considers NDE symptoms as intentional. That these could be partly accidental (the pairing of oxygen deprivation and carbon dioxide saturation leading to euphoria, tunnel vision, out of body experiences, and lights) and partly an intentional adaptation (activation of memory centers and wish fulfillment) is simply not considered.

Instead, we have a model of the self as fundamentally incorporeal as the explanatory mechanism of the NDE. And yet, NDE symptoms occur in only 12 per cent of severe cardiac or resuscitation events. If we all have an incorporeal soul that is being filtered through our body, shouldn't these experiences be far more common? The Kellys borrow from 19th century psychic researcher FWH Meyers in answering that only those with a sufficiently permeable barrier between their physical and immaterial mental selves are able to experience the phenomenon. Now, a physical model would explain the relative scarcity of NDEs on the basis of chemical conditions, semi-rare genetic dispositions, and perhaps the mechanism of neuron potentiation. The Kellys explain it by a 19th century notion of a gate between soul and body that for some reason opens all the way only for some people sometimes.

Do we have a full physical model of Near Death Experiences? We do not. However, the combination of physiology, neural network theory, and evolutionary biology is solving the little puzzles one by one. The pace isn't perhaps what the Kellys would prefer (patience is not one of Edward Kelly's strong points – his tale of abandoning neural computer modelling in the 1970s because punchcard-based computers weren't able to instantly mimic human linguistic behavior to his standards being a somewhat amusing incident of jumping ship a TAD early.) But just because we don't have an answer right now doesn't mean we get to shove the incorporeal soul edgewise into the gap. Or, as Antonio Damasio said in a slightly different context, "The possibility of explaining mind and consciousness parsimoniously, within the confines of neurobiology as currently conceived, remains open; it should not be abandoned unless the technical and theoretical resources of neurobiology are exhausted, an unlikely prospect at the moment."

So it seems the soul, our long-suffering hero, will have to put its visions of restoration aside for a while yet, NDE research having proven rather more Atterbury than Monck. And though, when the answer is found, it will undoubtedly be an astonishingly complex but sensible material one, it must be said that that answer will owe much to the research accumulated and symptom criteria compiled by the Kellys, van Pommel, Greyson, and Grosso. Science is complicated like that.