Wednesday, August 14, 2013

Near Death Experiences: All in the Brain?

The archetypical milieu was described first by Raymond A. Moody in his blockbuster book, 'Life After Life'.  Somehow you ended up semi-  "croaked", and you find yourself floating up and out of your physical body. Then, you glide toward a "tunnel" and lo and behold, a searing white light envelops your field of vision. It then proceeds to enfold you with its love, or if you've not been a very good boy or girl - say spreading hate - you're required to first give a review of your life.

Bullshit or believable? It probably depends on where you stand in the faith-religious belief spectrum. Believers then are more likely to consider NDEs (near death experiences) have some validity while Materialists- Physicalists- Atheists think it's all tricks of the brain - performed while the person is in a vulnerable brain state, open to hallucinatory phantasmagorias.

Now, a new study reveals that rather than a partial ascent into an afterlife, the NDEs may merely be a bunch of neurons running loco in your brain. Constrain the discharges, and you out the NDE as easy as pulling the plug.  According to the lead researcher, neurologist Jimo Borjigin:

"A lot of people believed that what they saw was heaven, but science has given a convincing alternative."

What did science find? Neuroscientists at the University of Michigan recorded electro-encephalograph signals in nine anesthetized rats after inducing cardiac arrest. Within the first 30 seconds after the hearts had stopped, all the mammals exhibited a surge in brain activity that had features associated with consciousness and visual activation. The recorded bursts of activity even exceeded levels associated with the normal, awake state.

In other words, the little beasties are having the rodent version of an NDE. According to the senior author, anesthesiologist George Mashour:

"On a fundamental level this makes us think of the dying brain"

As in humans, species Homo Sapiens.

The study was published online Monday in The Proceedings of the National Academy of Sciences. Of course, religious types and many others will object on the basis that such a study is too "ratomorphic". They will argue that it is dangerous to over extrapolate EEG records from rats to humans. After all, rats have a much more primitive cerebral cortex.

Even co-authors Borjigin and Mashour hesitate to make a direct connection between the rat "NDEs" and the human variety.  They note the links are merely speculative and "provide a framework for human study."

This is why the recent study is perhaps better taken in context with an earlier book by Dr. Kevin Nelson: The Spiritual Doorway in the Brain: A Neurologist's Search for the God Experience.
Nelson is one of the world's leading researchers in the biology of near-death and other related experiences, and his book takes the reader from investigations of MRI (magnetic imaging resonance) studies of the brain to historical anecdotes and philosophical inquiry. Three decades of research led Dr. Nelson to a unique and unexpected conclusion about near-death experiences -- rather than arising from parts of the brain that are unique to higher cognitive functions, they actually involve the oldest, most primitive parts of our brain, and might also relate to having dreams while still awake. (What we call "lucid dreaming")

Note here that if the "oldest most primitive parts of the brain" are involved, there may well be continuity between the rat experiences and the human ones, because of course it is precisely those "most primitive regions" we share the most with rodents.

Two of the NDE aspects that came under scrutiny in Nelson's book are: the tunnel which people traverse, and the white light.

Regarding the tunnel, in his words:

"The tunnel is easy to explain. Much of the near-death experience is caused by low blood flow to the brain and to the head. When this happens, the eye fails before the brain fails. The outside field of vision goes first, but the center is preserved until the very end, so you develop a tunnel-like sensation. This sensation is also common in people who are about to faint."

As for the white light which beckons:

"As for the light, when your eye loses blood flow, light might become all that you're capable of seeing. Another reason for the light is the REM system, which is the "rapid eye movement" state of sleep. When the eye and the retina shut down, the remaining control system for vision is the REM system -- this is why you can see things when you're dreaming, and this type of vision might be activated during a near-death experience and cause a person to see light"

In other words, there is a totally physical explanation for both effects. No supernaturalist hokum need be invoked.

Another key aspect of the NDE is the "OBE" or out of body experience, and Nelson makes clear one can experience OBEs outside of the NDEs. In one experiment, scientists actually induced fainting episodes in the test subjects, and many of them had an out-of-body experience while they fainted, which also commonly occurs during real near-death experiences. So in fact, many individuals know what it's like to have a near-death experience.

In regard to some people who don't see a white light but rather a kind of "hell" or experience very distraught emotions in a dark place, Nelson explains that not everybody sees light, not everybody has a sense of euphoria -- some people actually have an unpleasant emotional response during the near-death experience. What generally happens here is the pleasure system of the brain is engaged. This happens with spiritual experiences in general. When the Russian novelist Dostoevsky faced execution and lived to tell about it, he related a story of ecstasy and spiritual awakening. The dopamine reward system seems to be activated when a person believes they are near death, and the REM system, counterintuitively, is also activated. Experiments have shown that if you destroy parts of the brain that support REM sleep, you also take away the effectiveness of the dopamine reward system. Many pieces of the puzzle are missing, but we know there's a connection.

In respect of whether the NDE really shows a person coming back from the dead, Nelson is adamant:

"Returning from death is not something that people do. When a person drowns in ice water, the brain cells shut down and stop functioning, but they don't die. But when a person's heart stops, their brain cells burst after about five minutes. When the cells burst, they're dead and don't come back. If the cells are frozen instead, they don't burst, and when they warm up, they start functioning again."

In other words, when you're gone, you're gone.

What about any God connection?

Nelson is clear and succinct:

"You don't need to know how the brain is working in order to dismiss God, and knowing how the brain works doesn't prove or disprove a God. These are separate questions. Does evolution prove that God doesn't exist? I don't think so. Does it make it easier to explain consciousness in a Godless universe? Yes, but you can also conclude that there is no God without knowing anything about evolution or how the brain works"

For now, one only needs to process that NDEs are no evidence that one can return from the dead, or that one even gleans some objective experience about it. Even the Bible agrees that there is nothing after death, for example Job (6:18) teaches that there is no existence after death; men "go to nothing, and perish," and "he that goeth down to the grave shall come up no more." (7:9). Meanwhile, The Book of Ecclesiastes (3:19-20) says men are like beasts; "as one dieth, so dieth the other," that man "hath no pre-eminence above a beast"; "all go into one place; all are of the dust, and all turn to dust again."

Readers may also wish to consult this Scientific American article:

The article on why so many seem to latch onto supernatural explanations:

"The reason people turn to supernatural explanations is that the mind abhors a vacuum of explanation. Because we do not yet have a fully natural explanation for mind and consciousness, people turn to supernatural explanations to fill the void. "

However, that doesn't make the supernatural plausible, and it is always preferable to find a physical explanation - even if only a tenuous hypothesis is available - than to jump onto the supernatural bandwagon.

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