Scientific theories of the NDE
Copyright © 2003 Near-Death Experiences & the Afterlife
The following are excerpts from
Jean Ritchie's excellent book
Death's Door. Here she describes all the various theories
explaining the near-death experience. These included the following:
the dying brain theory, Darwin's theory, the hallucination theory,
the temporal lobe theory, the lack of oxygen theory, the
depersonalization theory, the memory of birth theory, and finally,
the theory promoted on this website, the afterlife theory. It is
important to realize the fact that although the mechanism for the
dying process in the brain can be quantified, this by no means
proves the near-death experience is merely a vision produced by the
brain which ends upon permanent brain death. One can quantify a
television signal that traveled through the air waves and is being
processed by a television set. However, one cannot quantify the
television show itself being played on the screen by quantifying the
components of the television set. This analogy fits for the
near-death experience as well.
The Dying Brain Theory
This theory is one that has been popularized by Susan Blackmore
in her book
Dying To Live. One of the greatest strengths of the afterlife
theory and the argument that near-death experiences are real is also
one of its greatest weaknesses. The fact that all those who had
near-death experiences follow the same path toward the light, going
through similar stages on the way, makes a powerful case for the
whole thing being a profound spiritual journey to an afterlife where
everyone, from all ages and cultures, is welcome. But that same
case, the "sameness" evidence, is also a fundamental part of the
argument that the near-death experience is not a real experience,
not a spiritual voyage, but a function of the dying brain. All
brains, regardless of where in the world they come from, die in the
same way, say the skeptics. And that is why all near-death
experiences have essential core elements which are the same. It is
not because the dying person is traveling toward a beautiful
afterlife, but because the neurotransmitters in the brain are
shutting down and creating the same lovely illusions for all who are
near-death.
But why? Why should the dying brain do this, if it is just a
highly sophisticated lump of tissue? That question is one of the
most fundamental questions in the whole of human thinking. It boils
down to asking, are we individuals with "personalities" and
"souls" and "minds" that are exclusive to us? Or are we simply
bodies controlled by very clever computers, or brains, each of which
works a little differently from the rest, thus making each of us
unique, just as an Apple computer is different from an IBM, although
there are far more similarities between them than there are
differences?
Scientists and researchers are divided. There are some who want
to reduce the near-death experience to nothing more than a series of
brain reactions. Others, who accept the realness and validity of
the near-death experience, are nonetheless quite happy to see it put
into a scientific context. In other words, they are not frightened
of researching the experience rigorously, of finding out everything
that we possibly can about it, perhaps even being able to explain
aspects of it. But they can happily let that scientific aspect sit
alongside the deeply personal, life-enhancing evidence of those who
have actually been there.
There are very few people around, even among the skeptics, who
would deny that people have near-death experiences, and that they
are deeply affected by them because so many obviously sane and
well-balanced people have now come forward and talked about what
happened to them. What they do dispute is what causes a near-death
experience and what it means. There are two main strands of
research: one takes the psychological approach, which looks for
reasons for human beings to behave the way they do, and to think and
possibly to hallucinate the way they do. The other is the
straightforward physiological approach, which is searching for that
part of the brain which malfunctions and causes a near-death
experience. Increasingly, as in all brain research, not just that
connected with near-death experiences, the two approaches overlap.
The ruthless, depersonalized argument - that a near-death
experience is just the result of the brain beginning to die - is not
acceptable to the vast majority of people who have had near-death
experiences. To reduce what was a profound and transforming
experience to nothing more than a set of neurotransmitters going on
the blink is a bit like seeing Michelangelo's statue of David as
nothing more than several tons of marble.
If there is no afterlife, and the near-death experience is just
the last throw of a fevered and dying brain, why does it bother? If
everything, including the soul and personality, is going to dust and
ashes, why does the brain lay on this last wonderful floor show for
people near-death, or facing actual death, who relax into
peacefulness and describe their wonderful visions?
If the near-death experience is just a hallucination, why do a
great many people report being told, "Your mission has not been
completed," or, "The time for your death is not yet," during their
near-death experience? If the near-death experience is just an
hallucination, how can so many people be hallucinating the same
thing? Isn't it odd that so many people are being told the same
thing? Are they all hallucinating identical responses? For many
people, it is easier to believe the near-death experience is a real
afterlife experience and not mass hallucination.
Darwin's Theory
One theory is that it is a deliberate ploy of the human race to
help those behind adapt better to the inevitable ending of their
lives. Darwin's
simple theory of the survival of the fittest holds that every
species is struggling to increase its hold on this planet and
guarantee the survival of its descendants. That is our greatest
primary urge. Other animals help their peers to survive: the dying
elephant, for example, trails away into the bush so that he does not
slow down the herd. Are the dying just "helping the herd" by putting
out propaganda that death does not contain a sting? But this theory
does not explain why near-death experiences are erratic, or why we
shunted down an evolutionary sidetrack for years by making them
something that people were reluctant to talk about. After all, in
Darwinian terms, humans are the complete masters of the universe.
The Hallucination Theory
Some scientists from the camp that believes the near-death
experience is one day going to be explained by brain functions have
suggested that the dying secrete endorphins, hormones which act on
the central nervous system to suppress pain and which are known to
create the "runner's high", which happens when long-distance runners
go through a pain barrier and find themselves running with ease and
without tiredness, and with a feeling of elation. But endorphins are
not hallucinogens and cannot re-create a state like a near-death
experience, so although they may be involved in the process as a
painkiller, they are not responsible for the whole experience.
Research on neurotransmitter receptors is highly complex and, in
terms of our understanding of the functioning of the brain, in its
infancy. It is known that a powerful anesthetic called
ketamine can produce many of the features of a near-death
experience, particularly the out-of-body element, and one theory is
that a ketamine-like substance may be released by the body at the
time of a near-death experience, and may attach itself to certain
neurotransmitter receptors and be responsible for producing the
whole near-death experience by blocking those receptors.
A psychology professor named
Ronald Siegel from UCLA rejects the spiritual and mystical
importance of the near-death experience. He claims to have
reproduced near-death experiences in his laboratory by giving LSD to
volunteers, but, other researchers say that although drug-induced
hallucinations may have some resemblance to near-death experiences,
they are not the same. For one thing, drug induced hallucinations
often evoke fearful and paranoid experiences which are not generally
found in the near-death experience. Drug induced hallucinations
distort reality while the near-death experience has been described
as "hyper-reality."
The Temporal Lobe Theory
Some features of the near-death experience are known to occur in
a type of
epilepsy associated with damage to the temporal lobe of the brain,
and researchers have found that by electrically stimulating this
lobe they can mimic some elements of the near-death experience, such
as leaving oneself behind, and the sense of life memories flashing
past, although this is actually a common feature of near-death
experiences. They believe that the stress of being near-death, or
thinking that you are near-death, may in some way cause the
stimulation of this lobe. There is some evidence to support this
theory in the lower numbers of near-death experiences reported by
people who suffer strokes which affect this part of the brain, or
have tumors in this area. But there is also a case against: the
characteristic emotions that result from temporal lobe stimulation
are fear, sadness, and loneliness, not the calm and love of a
near-death experience. Also, scientists may be simply discovering
the mechanism connected with the mind/body separation thought by
some to occur at death. Because a chemical mechanism is present in
the brain, this does not mean the near-death experience is strictly
a chemical reaction. Science may only be describing the aspect of
dying that deals with the brain.
The Lack of Oxygen Theory
Other possible explanations are a
lack of oxygen in the brain, or too much carbon dioxide. But
these would not explain why some patients are able to give full and
cogent reports of things that went on around them during their
near-death experience. Cardiologist Michael Sabom has reported one
patient who, while having a near-death experience, watched his
doctor perform a blood test that revealed both high oxygen and low
carbon dioxide. And comparisons of near-death experiences with the
hallucinations produced by an oxygen-starved brain show that the
latter are chaotic and much more similar to
psychotic hallucinations. Confusion, disorientation, and fear
are the typical characteristics, compared with the tranquility,
calm, and sense of order of a near-death experience. There are some
features in common: a sense of well-being and power, and themes of
death and dying. But people who have experienced both at different
times say that there is an unmistakable difference.
Hallucinations, whether deliberately drug-induced, the result of
medication, or caused by oxygen deprivation, almost always take
place while the subject is awake and conscious, whereas near-death
experiences happen during unconsciousness, sometimes when the
subject is so close to death that no record of brain activity is
recorded on an electroencephalograph, the machine that monitors
brain waves. Also, the medical conditions that take subjects to the
brink of death, and to having near-death experiences, do not
necessarily include oxygen-deprivation, or any medication. This is
particularly true of accident victims. Near-death experiences appear
to occur at the moment when the threat of death occurs, not
necessarily at the time, maybe hours later, when death is close
enough to be starving the brain of oxygen.
The Depersonalization Theory
The first modern attempt to explain near-death experiences in
psychological terms was made in 1930 by a psychologist who argued
that people faced with an unpleasant reality of death and illness
attempt to replace it with pleasurable fantasies to protect
themselves. They "depersonalize", removing themselves from
themselves - the floating away from their own bodies that
near-death experiencers have. It is a theory that is still
sometimes put forward, but it can be countered by the fact that some
typical features of a near-death experience just do not fit into the
depersonalization mode, such as the strong spiritual and
mystical feelings, and the increased alertness and awareness.
The Memory Of Birth Theory
Another popular theory is that the near-death experience has
nothing to do with death at all, but it is a
memory of birth. A baby being born leaves the womb to travel
down a tunnel towards a light, and what waits for it in the light is
usually a great deal of love and warmth. What happens at the point
of death is only a stored memory of what happened when life began.
Yet again there are a lot of points that don't match: a baby being
born does not exactly float at high speed down a tunnel, but is
buffeted along with difficulty by its mother's contractions. And how
does this model explain the meeting with friends and relatives who
have died? The "being of light" is supposed to be the midwife or
the doctor who rules the delivery room - but many babies are born
without a midwife or doctor present, or perhaps with many people
present. On a purely practical level, a baby's nervous system is not
sufficiently developed to allow it to assimilate and store memories
of the birth process.
Those who argue this theory say that the feelings of peace and
bliss are a memory of the peace of the womb when all physical needs
were met by the mother and there were no stresses and strains. Why
should this be any more likely than the feelings of peace and bliss
are relief from the pain of illness and injury at the point of
death? However, being born is often not a pleasant experience for
babies which leaves them crying as if in agony. In contrast, the
near-death experience is more often described as the most
pleasurable experience a person can have. The birth process is not
pleasant.
The Afterlife Theory
Melvin Morse, who did all the ground-breaking research with young
children, states unequivocally, "There is no explanation for the
light."
Kenneth Ring, perhaps the most respected of all near-death
experience researchers, and the one who did most to put the subject
on the academic map, says: "Any adequate neurological explanation
would have to be capable of showing how the entire complex of
phenomena associated with the core experience (that is, the
out-of-body state, paranormal knowledge, the tunnel, the golden
light, the voice or presence, the appearance of deceased relatives,
beautiful vistas, and so forth) would be expected to occur in
subjectively authentic fashion as a consequence of specific
neurological events triggered by the approach of death ... I am
tempted to argue that the burden of proof has now shifted to those
who wish to explain near-death experiences in this way."
Those sentences are a couple of complicated sentences, but what
Kenneth Ring is saying is that there are so many consistent features
of near-death experiences that it is going to be very difficult to
find a good explanation for them in terms of the physical working of
the brain. And, he believes, that the evidence is so strong for them
that sympathetic researchers should no longer feel that the burden
is on to them to prove that they happen, but rather, for the
skeptics to prove that they don't.
Perhaps the final word should go to Nancy Evans Bush, a
near-death experiencer with the
International
Association for Near-Death Studies, who said: "There is no human
experience of any description that can't simply be reduced to a
biological process, but that in no way offsets the meaning those
experiences have for us - whether it's falling in love, or grieving,
or having a baby." Or coming close to death and having a
transcendental experience.
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