“He came in with a really incredible story,” says Nelson. “As he was lying there, the devil came to take his soul, but a guardian
angel came to him, on his shoulder, and then along came Jesus Christ, his savior, who dispelled the devil—and at that point
he knew he was no longer meant to leave this earth, and he almost immediately made a good recovery.”
Nelson was glad to see the man doing well—he had grown to like him in the ICU—but he didn’t put much stock in the story. “I
was dismissive,” says Nelson. “But I was struck by the intensity of his experience and how powerful it was. I kept the painting
for years.”
At the University of Kentucky in Lexington, Nelson is what’s known as a neurophysiologist, specializing in treating muscle
diseases like multiple sclerosis or myasthenia gravis. But even as he settled into his specialty, the same curiosity that
nagged at Parnia started tugging on Nelson’s sleeve. He found himself thinking more and more about the man who claimed that
a guardian angel and Jesus had saved him from a heart attack. “In the back of my mind, I was thinking that not a single neurologist
had ever paid attention to the phenomenon of near death,” said Nelson. The brain must be central to the experience, he reasoned,
just as it’s central to any experience. And yet the only doctors who had taken the time to study NDEs were cardiologists or
psychologists or even oncologists like Jeffrey Long, who runs the Near Death Experience Research Foundation (NDERF). Says
Nelson, “These are not the neuroscientists who really know how the brain works.”
Nelson closely read the first-person accounts in Moody’s
Life After Life
, searching for clues the way a physician looks for clues in a patient’s medical history. There was one account that particularly
struck him. A woman was lying in a hospital’s radiology suite, waiting for a scan of her liver, when she suffered a severe
allergic reaction to a medication. She told Moody that she heard the radiologist walk over to a telephone on the wall, dial,
and say, “Dr. James, I’ve killed your patient, Mrs. Martin.” She struggled to let them know she was still alive but couldn’t
move a muscle. In this frozen manner, she watched and listened as an emergency team worked to revive her. She could see the
needles going into her skin but couldn’t feel them.
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Says Nelson, “She felt wide awake, and yet she was unable to move. I thought, what causes transient paralysis? Because that’s
what it sounds like, to a neurologist. I started thinking in terms of normal physical processes that cause paralysis, and
what came to mind immediately was something we experience several times a night, and that’s the REM stage of sleep. And then,
many things started falling into place.”
For Nelson, everything about an NDE—from the glowing light to the out-of-body experience to the mystical feeling—can be explained
by a glitch in the body’s sleep-wake machinery. More specifically, Nelson believes the near-death experience can be explained
as a manifestation of a REM state—the same REM that we experience in deep sleep, when we dream.
Most people don’t realize just how complex our sleep is, but anyone who’s ever had trouble falling asleep, or struggled to
drag themselves out of bed, can understand that sleep is more than a simple on-off switch. Healthy sleep involves multiple
phases and multiple shifts in brain activity. Most of us have heard of REM sleep, named for the rapid eye movements—underneath
the eyelids—that occur in this stage. In a healthy person, the REM stage makes up about 20 or 25 percent of total sleep time.
The body and brain exhibit several distinctive changes. Aside from the eye movements, during REM sleep the body is paralyzed—a
condition known as atonia. This is controlled by the brain, which during REM sleep stops releasing certain chemical transmitters,
including serotonin and dopamine, which typically permit the muscles to be active.
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It’s not uncommon for the gears of this machinery to get out of sync, so we’re not completely awake or asleep at some given
time. This can lead to some pretty weird behavior. Perhaps the most debilitating yet fascinating condition occurs when the
REM stages break down and muscle paralysis doesn’t occur. Sufferers may act out dreams or do bizarre things in their sleep,
like trying to have sex or even lashing out with their fists. The condition is called REM behavior disorder. In severe cases,
spouses have seriously injured each other or been forced to sleep in different beds for years. There was even an infamous
case in Canada where a man named Kenneth Parks drove across town, broke into a house, and stabbed his wife’s parents to death—all
supposedly while asleep. Bizarre as it sounds, a jury acquitted Parks of murder, after hearing testimony that several members
of his family suffered from extreme versions of REM behavior disorder.
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Aside from oddities like this, the REM stage is when we dream. Dreams, as we all know, can be unsettling, joyful, or terrifying—sometimes
all in the same dream. But when thinking about that stunning bright light, it is important to know that the sights and sounds
of our dreams are processed in parts of the brain that are different from the brain regions processing the sights and sounds
we experience in our actual lives. For example, blind people are known to sometimes “see” things when they dream—especially
if they’ve experienced sight at some point in their lives.
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What struck Nelson is that hearing about a near-death experience sounds a lot like someone telling you what they dreamed the
night before. “If you listen to these near-death experiences, they’re narratives—stories—and there’s a plot. It’s very action
oriented. There’s a lot of emotion, but very little language,” says Nelson. That’s the ineffability described by Moody. While
some people can recount dreams in great detail, most of us have a lot of trouble describing just what happened in a dream.
Time is slowed or distorted, and it’s hard to remember the sequence of events. Once we awake, what’s left is mostly a feeling—and
maybe a few intense images. “If you’re awake and kick in the dream machinery, the key brain parts are, number one, the limbic
system, and two, the activation of the visual system. That’s what really gets turned on when you’re dreaming.”
The limbic system is the network of brain structures that is involved in our emotions. It includes the hippocampus, which
is vital to making new memories, and the amygdala, which not only plays a key role in memory, but is central to our stress
response and its interplay with our emotions. According to Nelson, “Dreams are a play out of emotion more than anything else.”
It was sounding more and more as if sleep, dreams, and near-death experience were linked. According to the hypothesis, a near-death
experience could be thought of as a sudden and powerful sleep episode interwoven with elaborate dreams.
If you want to try and find a scientific basis for an NDE, you also have to explain one of its cardinal features: the bright
light—usually perceived in a sacred, awestruck manner. The “dead” person finds himself moving through a gloomy darkness, drawn
inexorably to the brightness. Raymond Moody called this “the Being of Light” and wrote, “What is perhaps the most incredible
common element in the accounts I have studied, and is certainly the element which has the most profound effect upon the individual,
is the encounter with a very bright light” of “indescribable brilliance.” According to Nelson, this can also be explained
by a connection to REM sleep, because several studies have found increased activity in the brain’s visual centers during the
REM stage.
Nelson tested his hypothesis by interviewing fifty-five people who had reported a near-death experience. What he found is
that people who have had an NDE are far more prone to REM intrusion than non-NDEers. Of the fifty-five “experiencers,” thirty-three—60
percent—reported experiencing REM intrusion compared to just 24 percent of a control group. A participant was recorded as
experiencing REM intrusion if they reported ever experiencing sleep paralysis, visual or auditory hallucinations around sleep,
or cataplexy—sudden incidence of muscle weakness, which in extreme cases has been mistaken for death. One such sufferer—a
woman named Allison Burchell—was famously taken to the morgue, while still alive, three times. NDEers are also eight times
more likely to answer yes to the question “Just before falling asleep or awakening, have you had the sense that you are outside
your body and watching yourself?”
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It’s a small study and the results are not definitive, but Nelson is confident he’s cracked the code. The feeling of being
dead would be caused by REM atonia—sleep paralysis. The tunnel and light would stem from loss of blood flow to the retina,
combined with REM-stimulated visual imagery in the brain. The emotional aspects of the NDE would be fueled by the limbic system.
An out-of-body feeling is common in the REM state and can also be triggered by stimulation of the same brain regions.
Nelson points out a few other things, as well. We know that a lack of oxygen can trigger an out-of-body reaction. Fighter
pilots who experience blackouts or near blackouts from extreme g-forces—which block blood flow to the brain—often report intense
dreams or dream imagery. There was also a 1994 study by a researcher who trained a bunch of college kids to hyperventilate
and then suddenly stand up. Head rush, man! Not surprisingly, a fair number of the students reported brief blackouts; many
also reported an out-of-body experience. I should also note that a life-threatening moment can be extremely stressful, and
we know that stress can cause shortness of breath and perhaps a shortage of oxygen.
But here’s something less obvious: stick your face into ice-cold water, and you will find yourself instantly gasping for breath.
That’s the diving reflex—sometimes referred to as the vagal reflex, named for the vagus nerve; it is so powerful that there
are cases where people suffocated before they had a chance to drown after falling from a boat into icy waters.
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The nerve can also be triggered by
emotional
stress. It sounds weird, but think about people who faint when they’re extremely frightened—that’s emotion triggering the
vagal reflex.
Intriguingly, Nelson says you can trigger a REM-like state by stimulating that very same vagus nerve. This could help explain
something that was nagging me before I heard his theory. People who go through a terrifying experience unharmed—such as someone
who narrowly avoids a head-on highway collision—may also describe aspects of an NDE, like an out-of-body experience or a sense
of time slowing down. Of course, all these NDEs and out-of-body experiences could just be the brain’s protective reflex, a
way to protect you from intense fear and stress. While the rest of your body is fighting for its life, your brain transports
you to another place, full of bright tunnels and strong emotions.
Nelson’s theory is fascinating, but it has raised a lot of hackles among other near-death researchers. After Nelson’s study
was published, Jeffrey Long and a therapist named Janice Miner Holden published a detailed thirty-five-page critique politely
but firmly challenging every one of Nelson’s conclusions.
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Long (who had helped Nelson to recruit research subjects) is a radiation oncologist who runs one of the most prominent websites
in the near-death community. Long says his Near Death Experience Research Foundation (NDERF) is a public service—he runs no
advertising and takes no money for the work. According to Long, the NDERF website,
nderf.org
, receives more than fifty thousand unique visitors every month from more than twenty countries (Poles seem to take a special
interest—there were 2,500 visitors from Poland alone the month we first spoke). Over the years, more than 1,600 people have
described their NDEs and taken the time to fill out an elaborate questionnaire.
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Long is a restless soul. Born and raised in Iowa, he says he’s been licensed in ten different states over the past two decades.
He moved to Albuquerque in early 2007 because he wanted to work with patients from the nearby Navajo territory. He traces
his interest in NDEs to an article he stumbled across in 1986, by the Atlanta cardiologist and author Michael Sabom. “I was
immediately fascinated. It should be impossible to be clinically dead and still have these lucid experiences,” says Long.
“I was astounded, and I remember vividly wondering, ‘Why aren’t more people studying this?’ ” He committed to doing the research
himself after a drunken evening with a friend and his wife, where the wife told the story of an NDE she had had many years
earlier—an experience where she coded on the operating table due to a severe allergic reaction; she says she floated away
from her body, down the hall to a nursing station.
Long complains that Nelson’s comparison group—the non-NDEers—is not typical; many are medical professionals and colleagues
of Nelson. He also told me the research questionnaire was poorly designed and that Nelson fails to recognize dramatic differences
between near-death experience and REM intrusion. For one thing, says Long, hallucinations stemming from REM intrusion—just
before waking, or while falling asleep—are often “bizarre and unrealistic,” such as seeing objects appear through cracks in
a wall or movement in a painting on the wall. By contrast, says Long, memories from an NDE are lucid and rooted in the real
world.
“NDEers almost uniformly don’t say, ‘Oh, that must have been a dream.’ [On the website] we ask if they were conscious and
alert, and about 75 percent say they were
more
alert,
more
conscious than normal,” says Long. What’s more, “there’s a consistency of elements. This is not like a hallucination.”
After hearing thousands upon thousands of NDEs, Long wonders, “Why do people 98 percent of the time encounter deceased relatives,
as opposed to [their] dreams where it’s common to encounter living people? We’ve even had people encounter deceased relatives
who[m] they didn’t know at the time were dead… . The totality of evidence shows there’s something going on that’s outside
the medical evidence. NDEers almost always say, ‘That wasn’t a dream.’ It was some different realm, some different aspect
of their existence.”