Near-Death Experiences

[yolland]

Sleep-wake mix-up may lead to near-death sensation

By Amy Norton
Reuters, Apr 17, 2006

The brain's tendency to occasionally blur the line between sleep and wakefulness may help explain the phenomenon of near-death experience, preliminary research suggests.

It's been an open question as to why some people see bright light, feel detached from their bodies or have other extraordinary sensations when they are close to dying or believe they might die. Some people view these so-called near-death experiences as evidence of life after death, and many neurologists have considered the phenomenon too complex for scientific study. But the new research, published in the journal Neurology, implicates the blending of sleep and wake states as a biological cause of near-death experiences.

Researchers found that adults who said they'd had such an experience were also likely to have a history of what's called REM intrusion--where aspects of the dream state of sleep spill over into wakefulness. People may, for example, feel paralyzed when they first wake up, or have visual or auditory hallucinations as they fall asleep or awaken. Of the 55 study participants who'd had a near-death experience, 60% had also experienced REM intrusion at some point in their lives. That compared with 24% of 55 adults who served as a comparison group.

The findings suggest that the brain's arousal system predisposes some people to both REM intrusion and near-death experience, according to the study authors, led by Dr. Kevin R. Nelson, a neurologist at the University of Kentucky in Lexington. This arousal system, Nelson explained in an interview, regulates not only REM sleep, but also attention and alertness during waking hours--including during dangerous situations. And many of the features of REM intrusions, he said, parallel those of near-death experience.

During REM sleep, visual centers in the brain are highly active, while the limb muscles are temporarily paralyzed. So REM intrusion during peril could promote the visions of light and sensation of "being dead" that people often have during a near-death experience, according to Nelson. Other evidence supports a role for REM intrusion in near-death experiences, he said. One important fact is that stimulation of the vagus nerve, which connects the brain stem to the heart, lungs and intestines, triggers REM intrusion. And heightened activity in this nerve is sure to be part of the body's "fight-or-flight" response to danger.

Still, Nelson said he doesn't think REM intrusion will turn out to be the "whole explanation" for near-death experience, and the findings shouldn't detract from the meaning people have taken from their experiences. "My work is spiritually neutral," Nelson said, noting that the research can only look at how the brain contributes to near-death experience, and not why the phenomenon occurs.

"The 'why' can't be addressed by scientific inquiry," he said.

Some stuff from Answers.com:

near-death experience: phenomenon reported by some people who have been clinically dead, then returned to life. Descriptions of the experience differ slightly in detail from person to person, but usually share some basic elements: a feeling of being outside one's body, a sensation of sliding down a long tunnel, and the appearance of a bright light at the end of that tunnel. The light is sometimes described as a benevolent "being of light" who directs the person in a review of his or her life so far and ultimately prevents the person from crossing some sort of boundary that signifies death. Most people who have had a near-death experience report that it strongly influences their subsequent lives, relieving anxiety about death and increasing their sense of purpose and their sensitivity to others.

Research into the near-death experience was pioneered by Raymond Moody, who published Life After Life in 1975 after studying 150 people who had had such experiences. He and other scientists, such as cardiologist Michael Sabom, found that possible physiological and psychological causes for the phenomenon, including lack of oxygen to the brain, the influence of anesthetics, disruptions in neurotransmitter release, and prior expectations, could not sufficiently account for the experiences these people described. Their findings and a belief in a spiritual explanation for the phenomenon have been supported by Elisabeth Kübler-Ross, who pioneered the study of death and dying in the United States beginning in the late 1960s.

A well-known scientific hypothesis that attempts to explain NDEs was originally suggested by Dr. Karl Jansen (1995) and deals with accounts of the side-effects of the drug Ketamine. Ketamine was used as an anesthetic on U.S. soldiers during the Vietnam War, but its use was abandoned and never spread to civilian use because the soldiers complained about sensations of floating above their body and seeing bright lights. Further experiments by numerous researchers verified that intravenous injections of ketamine could reproduce all of the commonly cited features of an NDE, including a sense that the experience is "real" and that one is actually dead, separation from the body, visions of loved ones, and transcendent mystical experiences.

Ketamine acts in part by blocking the NMDA receptor for the neurotransmitter glutamate. Glutamate is released in abundance when brain cells die, and if it weren't blocked, the glutamate overload would cause other brain cells to die as well. In the presence of excess glutamate, the brain releases its own NMDA receptor blocker to defend itself; and it is these blockers Dr. Jansen (amongst others) hypothesize as the cause of many NDEs.

[But] Dr. Jansen's own shifting perspective on the conclusions to be drawn from the ketamine-NDE analogy has been notable. He started out as an unequivocal debunker of the notion that NDE's are evidence of a spiritual (or at least transnormal) realm. But with time he has developed a more agnostic hypothesis: that ketamine may in fact be one particularly powerful trigger of authentic spiritual experiences, of which near-death may be another. In each case, according to Jansen's more recent pronouncements, all we can say is that the subject gets catapulted out of ordinary "egoic" consciousness into an altered state--we cannot comfortably rule out the possibility that the "worlds" disclosed in these "trips" have ontological status.

Not a topic I've thought much about really, but I would be curious to see what other people in here think or have to share. I know at least one person who feels her life was changed by what she strongly believes to have been one of these "ontological" sorts of near-death experiences, and of course there have been several bestselling books in recent years on the subject. Also, I remember Irvine once describing an "REM intrusion"-type experience like those mentioned in the first article...

 

[Angela Harlem]

I was a sleep walker for many years and the experience of it was...well, hard to explain. Especially as I did strange but otherwise very ordinary things while asleep. I've never had a near-death experience, though. Only those fleeting moments where time seems to slow down and we see life move in a rigid scene by scene play. I'd not liken the 2, if they are considered near death experiences - in the instances where you think you might be nearing the end.

 

[Judah]

It may be impossible to scientifically determine whether NDE are actually pointers to an afterlife or whatever.

Even if all the scientific research points to people's NDE recollections as reduced to strictly brain-chemical processes...it would be no evidence for or against the idea/belief of an afterlife. So, I don't know whether any personal recollections on this are that helpful.

[With that said, my brother-in-law had a massive heart attack this past December. He flatlined twice, was revived twice...he's fine now. But the first thing i asked him was: "Didja see the light? Didja float away and see all the docs working to revive you?" And he said "Nope. Saw nothing. All i 'remember' is darkness, from the time i passed out at home to the time i awoke in the hospital."]

 

[Irvine511]

Also, I remember Irvine once describing an "REM intrusion"-type experience like those mentioned in the first article...

yes, sort of. this stuff tends to happen whenever i'm exhausted and taking a nap to catch up on sleep that i've missed -- it's really kind of remarkable what happens. it can be terribly confusing, especially when you dream waking up when you're still asleep, or when you think you're awake but you're still asleep only it feels as if elements of the dream world have invaded the real world. i can remember being convinced that i was paralyzed, for example. i also remember dreaming that i had woken up and brushed my teeth and went into the other room where my boyfriend was watching TV and the only thing that cued me in to the fact that i was dreaming was that he had long hair (he has a military buzz cut in real life). and that was the only thing that cued me into the fact that i was still asleep -- intersting how the mind works, how it took an incorrect detail to cue me into the unreality of the situation.

a few weeks ago i had one of those lucid dreams wherein i was completely aware that i was having a lucid dream, and i tried to be very aware of where i was and what i was doing and even trying to exercise some sort of control over my dream environment. it was actually a bit of a strain, mentally, as i remember trying very hard to "do" things (kind of like "reading" in a dream) but i still woke up generally refreshed.

anyway, it wouldn't at all surprise me to learn that such experiences zooming in and out of REM sleep are akin to a near death experience, it seems like something happens when the body is paralyzed and such experience i've described above could very easily be similar to near death experiences like when people talk about floating above their bodies after a car accident or drug overdose (the Motley Crue "behind the music," anyone?) and such an explanation makes more sense than the soul/ghost of a person (like in "Ghost") hovering above the body before being sucked back in.

 

[A_Wanderer]

It may be impossible to scientifically determine whether NDE are actually pointers to an afterlife or whatever.

Even if all the scientific research points to people's NDE recollections as reduced to strictly brain-chemical processes...it would be no evidence for or against the idea/belief of an afterlife. So, I don't know whether any personal recollections on this are that helpful.

[With that said, my brother-in-law had a massive heart attack this past December. He flatlined twice, was revived twice...he's fine now. But the first thing i asked him was: "Didja see the light? Didja float away and see all the docs working to revive you?" And he said "Nope. Saw nothing. All i 'remember' is darkness, from the time i passed out at home to the time i awoke in the hospital."]

There is no evidence for an afterlife, the laws of conservation of mass and energy are strongly against the existence of an afterlife.

 

[Judah]

There is no evidence for an afterlife, the laws of conservation of mass and energy are strongly against the existence of an afterlife.

Yes, A_W, i totally agree (i'm a rabid athiest). My point was that a belief in an afterlife is a metaphysical belief and would be hard to prove either way through scientific methods.

 

[joyfulgirl]

Re: Re: Near-Death Experiences

i can remember being convinced that i was paralyzed, for example.

This happened to me frequently as a child. If it's like my experience, it's actually called sleep paralysis and the definition fits my experiences exactly. Was your experience like this?

Sleep paralysis is a condition that occurs in the state just before dropping off to sleep (the hypnagogic state) or just before fully awakening from sleep (the hypnopompic state). The condition is characterized by being unable to move or speak. It is often associated with a feeling that there is some sort of presence, a feeling which often arouses fear but is also accompanied by an inability to cry out. The paralysis may last only a few seconds.

There is actually a good explanation from a metaphysical standpoint but I'm not sure if I want to go there in this thread.

 

[Irvine511]

Re: Re: Re: Near-Death Experiences

This happened to me frequently as a child. If it's like my experience, it's actually called sleep paralysis and the definition fits my experiences exactly. Was your experience like this?

Sleep paralysis is a condition that occurs in the state just before dropping off to sleep (the hypnagogic state) or just before fully awakening from sleep (the hypnopompic state). The condition is characterized by being unable to move or speak. It is often associated with a feeling that there is some sort of presence, a feeling which often arouses fear but is also accompanied by an inability to cry out. The paralysis may last only a few seconds.

There is actually a good explanation from a metaphysical standpoint but I'm not sure if I want to go there in this thread.

i try to cry out and speak frequently when this happens (never during night sleep, it only really happens when i nap), and i would love to hear your metaphysical explanation.

please PM it to me if you don't want to go there here.

 

[joyfulgirl]

Re: Re: Re: Re: Near-Death Experiences

i try to cry out and speak frequently when this happens (never during night sleep, it only really happens when i nap), and i would love to hear your metaphysical explanation.

Same here. Since I was also an insomniac when I was a kid, my night sleep was often like naps so for me it happened during the night as well but most often during an afternoon nap. Ok, let me think about it. Not even sure how to approach the whole subject yet.