Tunnels of light. Meeting with dead loved ones...
the truth about near-death experiences
Are those extraordinary stories proof of the
afterlife - or plain hokum? A top brain specialist
has a compelling new theory...
Gillian MacKenzie remembers feeling worried for
her unborn child, as the world around her fell
into darkness, save for a dot of brilliant light.
She was somehow aware that her delivery had gone
wrong and she was losing a lot of blood, but
there was comfort in the light.
`It was like a tiny pinprick at first and then
I realized I was being drawn closer to it and
it was getting bigger and bigger,' she says.
I felt no fear as I went into the tunnel and
emerged fully into the brilliance. There was
the most wonderful feeling of bliss. I can only
describe it as ecstasy.
Suddenly I heard a man's voice saying: "Gill."
It was a very nice voice and I thought:
"Oh no, I've come before God and I don't even
believe in Him!" He asked if I knew who he was
and I said: "Yes, but I'm afraid I can't say
your name." He obviously had a sense of humour
because he chuckled at that.'
Gillian's experience happened many years ago,
before the term near-death experience had been
coined, but it is as real to her today as it
was when she began haemorrhaging during a
No one knows for sure, but scientists believe
as many as one in ten of us will have a near-death
experience, most likely during cardiac arrest.
Typically, we will see a light, travel through
a tunnel, have an encounter with a lost loved
one or float above ourselves and watch doctors
and nurses trying to resuscitate us.
Those who have had such experiences often
describe profound moments of joy and insight
that change them for ever.
Many believe they have had a glimpse of the
afterlife, an experience that shores up their
faith and leaves them unafraid of death. To them,
it is real, lucid and precious
It might come as something of a shock, then,
for them to learn that a respected American
neurologist believes he can explain all the
symptoms of near-death experience in physiological
terms terms that would firmly close the door
on thoughts of souls departing for the afterlife
before returning to Earth.
Kevin Nelson, Professor of Neurology at the
University of Kentucky, has been studying
near-death experiences for more than 30 years.
In his new book, The God Impulse Is Religion
Hardwired Into The Brain?, he puts forward explanations
for all elements of the near-death experience, but
central to his argument is the involvement of
REM rapid eye movement.
This is the time during sleep when we dream most
and during which the sleeper is paralysed apart
from the eye muscles, heart and diaphragm (which
Professor Nelson believes that some people are
more susceptible than others to a condition
called `REM intrusion', where the paralysis
that accompanies REM happens while an individual
is awake and is often accompanied by vivid
Research conducted by Professor Nelson examined
the cases of 55 people who had described having
a near-death experience.
Of those, 60 per cent had previously had episodes
of REM intrusion, compared with only 24 per
cent in a group of people chosen at random.
`Instead of passing directly between the REM state
and wakefulness, the brains of those with a
near- death experience are more likely to blend
the two states into one another,' he says.
This places the subject into what he calls the
`borderlands' of consciousness.
`Many people enter this unstable borderland for
only a few seconds or minutes before emerging
into REM or waking,' he says.
`In the borderland, paralysis, lights,
hallucinations and dreaming can come to us.
During a crisis such as a cardiac arrest, the
borderland could explain much of what we know
as the near-death experience.'
But what about the light, the tunnel, the
spiritual encounters and out-of-body experiences?
He has explanations for these, too.
In his study, Professor Nelson found that the
symptoms of near-death experiences happened
in fainting as well as during life-or-death
traumas such as heart attacks.
But what most of these episodes have in common
is a temporary interruption of blood flow to the brain.
`Normally, 20 per cent of the blood the heart
pumps sustains the brain,' he says. `If the blood
flow is reduced to a third of its normal supply,
the brain remains immediately active, but after
ten to 20 seconds, it loses consciousness.
`The brain sustains no injury, even if this
flow rate lasts for hours. At these marginal
flows, a person may slip in and out of consciousness.
`A great deal of what happens in the brain
during near-death experiences comes about because
of a reaction to the crisis of having low blood
flow, regardless of how briefly. When blood is
draining from the head, just before consciousness
is lost, the tissue that is most sensitive to
failure is not the brain, it is actually the eye,
`When the retina fails, darkness ensues and it
fails from the outside inwards, producing the
characteristic tunnel vision.
`The light at the end of the tunnel could come
from two different sources. It could be from
ambient light such as the background light in
a hospital emergency room which may be all the
brain can recognise as blood drains from the head.
`Alternatively, the REM system, which is known
for its robust activation of the visual system,
could generate light internally, within the brain.'
But people don't just see the tunnel they
feel themselves travelling through it. How
can this be?
`Well, the area of the brain associated with
out-of-body experiences, the temporoparietal
region, is right next to the area that is
responsible for our sensation of motion,' he says.
`Normally, this area gets turned off during REM
sleep, but in some cases it could be that this
process does not function properly, and that
during the transition into REM, the brain
experiences a sense of motion.'
That explains the visions, the light and tunnel,
but what about the floating out-of-body experience?
And the sensation of being dead?
The dead bit is easy this is down to the fact
that sleepers are paralysed during REM sleep,
otherwise they might hurt themselves acting
out their dreams.
To explain the out-of-body floating, Professor
Nelson refers to a piece of research conducted
by a neurologist in Switzerland called Olaf Blanke.
Blanke and his colleagues made an astonishing
discovery one day while preparing a 43-year-old
woman for surgery. She was suffering from seizures
and the surgeons were applying electrical impulses
to her brain to try to find out from where the
problem was emanating.
Suddenly, the woman, who had to be conscious for
the procedure, said she had floated outside her
body and was looking down on herself. The electrical
current was switched off and she returned to her body.
`The woman's sense of being in or out of her body
came and went with the mechanical predictability
of turning on a light switch,' says Professor
`The person manning the switch moved her
consciousness at will. It was as if the elevator
"up" button for an out-of-body experience had
Finally, feelings of bliss could be accounted
for by the brain's reward system. During moments
of extreme crisis, the body releases chemicals
that provide a sense of relaxation and well-being.
This is thought to be an evolutionary quirk that
stems back to prehistoric times. If a hunting party
had been cornered by a predator and was sure to be
killed, it made it easier for the rest of the group
to escape if the victim did not struggle too much.
The predator would expend time and energy consuming
one victim, making it easier for the others to
avoid the same fate.
But what does Gillian MacKenzie think of all this?
During her near-death experience, she met her
grandfather, Harry, who had died two years before.
She told him she had given birth to a boy which
was correct, though she had no way of knowing it
and she floated above herself, seeing doctors working
She also floated above her husband, Hamish, following
him down a hospital corridor and watching him phone
`I wasn't at all frightened, but I was wondering how
I was going to let Hamish know that everything was
going to be all right and that I would get back into
my body somehow,' she says.
Gillian, now a pensioner living in Eastbourne,
East Sussex, adds: `I told my grandfather that I
would have to leave and go back to look after my
husband and baby, but he said I had to present a
strong case for me to be allowed back.'
During the episode, Gillian re-lived memories, good
and bad, and said she came away with a better
understanding of her life.
For example, she had never forgiven her mother for
leaving her at boarding school and remembers crying
as she walked away.
`Re-living it made me realise that it must have been
so hard for her, too, hearing me crying and not
being allowed to look back at me,' she says. `I had
new insight and I told my grandfather that I would
have to go back to put this greater understanding
to good use in helping others. And then I went back.'
In later years, Gillian became a counsellor.
`Before the experience, I had been intolerant
with people. After it, I was a completely different
`So you can put a rational explanation for the
experiences of people like me, but that would be
missing the point. To us, they are real and they
have a profound effect on you and the way you
live your life afterwards. It took away any fear
I might have had of dying and I think it made me
a better person. You can call them hallucinations
if you want, but they are our reality.'
None of this is lost on Professor Nelson. He says
his work isn't intended to disprove the existence
of God or to diminish the importance of
`There is a widening schism between people who
think God is an anachronism and regard all
spiritual experience as a dangerous delusion and
those who consider religion [to be at] the core
of their lives,' he says.
`I was determined that someone based in
neuroscience should try to explain the nature
of spiritual experience, not explain it away.
`I treat all of these experiences with the
reverence and respect they deserve because
they are powerful to the people who have them.
They are the most powerful experiences that
many of them will ever have.
`So, yes, I might be trying to explain how and
why they happen in physiological terms, but I
would argue that isn't incompatible with people
believing in God if they want to.
'After all, who's to say that these mechanisms
weren't created by God in the first place precisely
to provide comfort just when we might need it
most as we approach death.'
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