Scientific theories of the
NDE
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Copyright © 2003 Near-Death Experiences & the Afterlife
Last modified: February 02, 2003 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. |
