By Steve Boggan
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 realised I was being drawn closer to it and it was getting bigger and bigger,’ she says. ‘The brightness was shining like the walls of a tunnel.
Lucid: Out-of-body experiences can change the course of people's lives - but can they be explained by how our brains work?
‘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.’
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
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 difficult childbirth.
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.
Dreaming could be a contributing factor to near-death experiences
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 controls breathing).
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 hallucinations.
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.
Some people believe they meet with dead relatives during their experience
‘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, the retina.
‘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 Nelson.
‘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 been discovered.’
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 on her.
She also floated above her husband, Hamish, following him down a hospital corridor and watching him phone her mother.
‘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 person.
‘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 near-death experiences.
‘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.’
The God Impulse — Is Religion Hardwired Into The Brain? by Kevin Nelson (Simon & Schuster, £16.99).
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