Near Death Experiences

A comparison of the effects of hypoxia to the reports of a brush with the afterlife.

by Brian Dunning

Filed under Health, Paranormal, Religion

Skeptoid #261
June 7, 2011
Podcast transcript | Listen | Subscribe

Today we're going to float around the operating room, look down at our own body lying there on the table, hear the heart monitor switch to a solid tone, and learn first-hand what some believe goes on during a near death experience. When a small percentage of people are near death or are temporarily dead, either from an accident or during emergency lifesaving treatment, they report eerie experiences that they interpret as having crossed the threshold into an afterlife. Some authors and researchers have catalogued these reports and concluded that the experiences must have been real, while some skeptical researchers have found that the experiences are the natural and expected result of low oxygen to the brain. It seems the perfect place to point our skeptical eye.

A favorite starting point when examining such tales is the application of Occam's Razor. This states that the explanation requiring the introduction of the fewest new assumptions about our world is probably the true one; in other words, the explanation that best fits our understanding of the way the world works. The supernatural explanation for near death experiences (NDEs) requires the existence of an afterlife, heaven or hell or whatever you prefer to call it. To science, which has never found any reason to suspect life might continue after the death of the body, such a place would be a major new assumption about our world. But to many people with certain religious beliefs, such a place is a given and the afterlife is real, and is thus not a new assumption. So to a lot of people, Occam's Razor does nothing to settle this particular question.

Probably everyone will agree to some extent that the brain is capable of generating surprising experiences, such as highly realistic dreams. We've all had faint or dizzy spells, and these can be pretty dramatic episodes even though, to an outsider, nothing notable happened physically. A bit later we'll talk about how all of the major events of an NDE are created in the brain in certain experiments. In summary, even those who believe that NDEs truly represent a brush with the afterlife probably agree that every experience that characterizes one can also be attributed to a natural cause. Why, then, is there a tendency to insist that they had to be an actual life after death experience?

In 1975, Dr. Raymond Moody published Life After Life, which became the seminal work promoting NDEs as evidence of an afterlife. Dr. Moody is a strong personal believer in not only the afterlife, but also reincarnation, claiming that he has personally lived nine previous lives. In his books he's cited 150 cases of people who, after resuscitation, reported extraordinary experiences.

Let's take a look at the reports. First, the basics. Although it's rare for any two stories to be substantially similar, there are common themes. One the most familiar is the life flashing before the eyes, a quick fast-forward replay of either the entire life or important events, even long-forgotten events, commonly called a life review. Perhaps the most popular report is a bright light, warm and inviting. Sometimes this is combined with a feeling of floating through a tunnel. Some NDEs include an out-of-body experience, usually floating in the air and seeing one's own body below, being tended to by medics, sometimes reporting seeing things happen that could not have been observed from the body's position. People with physical limitations, blind, deaf, or paralyzed, usually find that their bodies are whole during these experiences.

Some people report positive meetings with deceased loved ones or religious figures such as Jesus or Muhammad. Just as often, however, people report terrifying encounters with monsters, hated people, or the devil. So while many experiences are euphoric, many are very much the opposite.

So the question is, can we group all of these things together in such a way as to find an undeniable pattern? Is there enough consistency and predictability that we can conclude with good certainty that such a thing as an afterlife must exist, and here is the probable experience you'll have as you cross over? It's unlikely. When Skeptoid looked at The Hum, a worldwide acoustic phenomenon, we found enough variation to conclude that there are probable many different causes that likely have nothing to do with each other. NDEs are similarly complicated by many unrelated causes of characteristic experiences: drug effects, hypoxia, trauma, brain abnormalities, and simple dreaming, just to name a few. We'd expect people coming out of all these conditions to report things very similar to NDEs.

Let's take a look at out-of-body experiences. You can search the Internet and you'll easily find dozens (if not more) stories where someone floated off the operating table and made observations about the room, actions performed by surgical staff, and even things happening outside the room. I'm not even going to list them because there are so many, and I'll grant that many of them sound undeniable, that the only possible explanation is that the person's consciousness and perspective was indeed outside the body. Having read a lot of these, I make three observations:

1. I know a number of anesthesiologists. They are not impressed by these stories. It is common for patients to be aware during general anesthesia. They remember many details of the people, objects, and procedures in the room. We absolutely expect some number of supposedly unconscious patients to report things that happened that a layperson would assume were unknowable. In fact, The Lancet published research in 2001 that showed nearly 20% of patients retained memories of things that happened when they were clinically dead.

2. What's rarely or never written up in books is the fact that most such "recollections" get their details wrong, and were probably just imagined by the patient. When authors compile stories to promote the idea of NDEs, they tend to universally exclude these; in fact the majority were never recorded anywhere to begin with. If out-of-body experiences are truly part of passing over into the afterlife, then they usually represent an afterlife of some alternate universe where everything's wrong.

3. Some of the stories can't be explained by either of the above. They include specific details that the patient could not have known. Sadly, all of these are anecdotal. They're very interesting and I wish we had more of them, and that controls had been in place at the time. Since they weren't, the scientific method requires us to shrug and say "Neat, but not evidence, let's do it better next time."

As an example of the value of anecdotes in suggesting directions for research, Dr. Penny Sartori placed playing cards in obvious places on top of operating room cabinets at a hospital in Wales in 2001, while she was working as a nurse, as part of a supervised experiment. Although she's a believer in the afterlife, and documented fifteen cases of reported out-of-body experiences by patients during her research, not one person ever reported seeing the playing cards or even knowing they were there.

Life review, euphoria, bright lights, and meetings with sacred personages have all been correlated with high levels of carbon dioxide in the brain. Research published in the journal Critical Care in 2010 found that over one-fifth of heart attack patients who went into cardiac arrest and were resuscitated, all of whom would have had high CO2, reported these phenomena. But these patients were all also nearly dead; so the NDE correlates equally well with being near death as it does with the physiological condition. To find out which is the best correlation, we'd have to see whether an NDE can happen when one condition is present and the other is not.

It turns out that extensive research has been done to characterize a person's experience with loss of blood to the brain when there is no risk of death, by that patron saint of human experimentation, the US military. For 15 years, Dr. James Whinnery put hundreds of healthy young fighter pilots into centrifuges to understand what a pilot might experience under extreme gravitational loads. He put them in until they blacked out. Once they reached a point where there was inadequate bloodflow to the brain, they lost consciousness; and among the frequently reported experiences were the following: Bright light, floating through a tunnel, out of body experiences, vivid dreams of beautiful places, euphoria, rapid memories of past events, meeting with friends and family, and more. The list is an exact match with the events attributed by believers to a brush with the afterlife.

What about the reverse? Are there reliably documented reports of NDEs from people who were near death, but whose brains had normal oxygen supplies? If there are, I was not able to locate any. This leaves only one group of conditions that can be consistently correlated with what we call a near death experience, and it's not nearness to death. It's a set of brain conditions that includes hypoxia, hypercarbia, and anoxia.

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Other researchers have also found ways to produce the symptoms of a NDE without nearness to death being a factor. In 1996, Dr. Karl Jansen published his successful results of inducing a NDE using the drug ketamine. In 2002, Nature published research in which experimenters gave direct electrical stimulation to the part of the brain called the angular gyrus in the parietal lobe. Subjects reported being able to see themselves lying there from a vantage point near the ceiling, and were able to communicate what they observed as it was happening. Some brain surgeries, most notably those for epilepsy, produce very high rates of NDE reports from patients whose lives were not in danger.

But believers in the afterlife are quick to point out that just because the reported experiences have natural explanations, it doesn't prove that the supernatural explanation is not also true in at least some of the cases. That's true, of course. We'd love to have such proof. Most of the symptoms of NDEs, like seeing a bright light and feeling euphoric, are too vague to serve as proof of the afterlife. But one isn't, and that's the out-of-body experience. What science would love to find is a win in a controlled test, consisting of the disembodied consciousness successfully completing a task under controlled conditions. If the claims of the most interesting such stories are true, this should not be a problem. It hasn't happened yet — nobody's yet seen Dr. Sartori's hidden cards, or beaten any other similar tests — but here's to hoping that they do. We all hope that death is not the end. Perhaps someday someone will prove Raymond Moody right, and we can all look forward to a catlike nine lives.

Brian Dunning

© 2011 Skeptoid Media, Inc. Copyright information

References & Further Reading

Blackmore, S. "A Psychological Theory of the Out of Body Experience." Journal of Parapsychology. 1 Sep. 1984, Volume 48, Number 3: 201-218.

Blanke, O., Ortigue, S., Landis, T., Seeck, M. "Stimulating illusory own-body perceptions." Nature. 3 Oct. 2002, Volume 419: 269-270.

Braithwaite, J. "Towards a Cognitive Neuroscience of the Dying Brain." The Skeptic. 1 Jul. 2008, Volume 21, Number 2.

Jansen, K. "Using ketamine to induce the near death experience: Mechanism of action and therapeutic potential." Yearbook for Ethnomedicine and the Study of Consciousness. 1 Jan. 1995, Issue 4: 55-81.

Kruszelnicki, K. "Near-death myth alive and kicking." ABC Science. Australian Broadcasting Corporation, 8 Mar. 2007. Web. 3 Jun. 2011. <>

Moody, R. Coming Back: A Psychiatrist Explores Past-Life Journeys. New York: Bantam Books, 1991. 11-28.

Van Lommel, P., Van Wees, R., Meyers, V., Elfferich, I. "Near-death experience in survivors of cardiac arrest: A prospective study in the Netherlands." The Lancet. 15 Dec. 2001, Volume 358: 2039-2045.

Whinnery, J., Whinnery, A. "Acceleration-Induced Loss of Consciousness: A Review of 500 Episodes." Archives of Neurology. 1 Jul. 1990, Volume 47, Number 7: 764-776.

Reference this article:
Dunning, B. "Near Death Experiences." Skeptoid Podcast. Skeptoid Media, Inc., 7 Jun 2011. Web. 7 Jul 2015. <>


10 most recent comments | Show all 79 comments

Hello, Jen,

What you experienced may be what the experts are classifying an NDE.

To the thousands of folks that recant their experience, as they were floating over their bodies, their bodies weren't manipulating equipment or moving around.

The vast majority of folks who explain their NDE, and whose NDE is the same as others that they don't know, fully understand what they are experiencing as the event is taking place.

It isn't like you describe at all.

Therein lies the separation of what the experts suspect, and what an individual who has been through a Near Death Experience knows.

That difference is what makes a Near Death Experience so amazing. Thousands see and feel and experience the very same occurrence. To the folks that have been through an NDE, they no longer have any doubts as to what happens after death.

Conversely, those who have had a somewhat similar event following a lack of oxygen may want their experience to be the explanation for NDEs.

Yet, a lack of oxygen, while producing some unusual effects could never be confused with a Near Death Experience.

Those who have been through a Near Death Experience would notice a rather obvious difference between the descriptions of events promptly.

Suffice it to say, whenever an individual has had an NDE, life is somewhat different following the event. It would be safe to say that the folks with the NDE experience would no longer require experts to say whether or not NDEs exist, ...or why. Empirical evidence.

Jim Wilkerson, Houston, Texas
April 28, 2013 6:46pm

These quite rare veridical OBE's, which sometimes form a portion of the typical western NDE are interesting phenomenon in my veiw.

I'm most interested in these veridical OBE's, where the experiencer is in hospital, and is being monitored, and can be shown to have gone into cardiac arrest.

Henrik Ehrsson work (amongst others), appears to support the typical OBE, through shifting of self-location in space, and the difficulty the brain appears to have in perceiving the ‘self’ to be located at two different places at the same time.

There are important studies showing the modulation of local field potentials in the V1 and V2 visual areas of the brain correlate with perception.

Francis Crick & Christof Koch pose an important question in one of their papers... considering how does the brain, bind together in a mutually coherent way, all those neurons distributed throughout the brain, which are actively responding to different aspects of a perceived object?

More recently (2010) Frohlich & McCormick published a very interesting paper which demonstrates that neocortical neuronal networks may not only be defined by their anatomical interconnectivity and the status of the synaptic activity that binds them together, but also by the spatially and temporally complex Electro Magnetic Fields in which they are embedded.

No answers I'm afraid, just questions...

Max_B, UK
May 10, 2013 1:22pm

I was 7 times temporarily dead from 20-45 minutes. And its only lights off and if you are lucky lights on. Maybe I spent my 9 lives already :) And believe me, there's nothing interesting in dying.

Milos, Malmo
May 29, 2013 3:21pm

In one case, a four year old NDEer met his grandfather he never knew, and his sister who had passed on. Apparently she had died in the womb, and he was never told about her.
A neurosurgeon, who had no belief beforehand whatsoever, had a NDE. He wanted to find scientific evidence for this occurrence, but concluded that his brain had completely shut down, and there was no possibility of brain activity. How do you know better than a neurosurgeon what the brain is capable of?
In BOTH cases, the Heavenly accounts were identical and precise, and both came back having met Jesus and experiencing God's immeasurable love, as millions of others can attest to as well. Near term prophecies have been relayed and fulfilled, as well as consistent visions being imparted depicting the return of Jesus as relayed in Revelation, whose prophecies unfold as we speak. All those who had a Heavenly experience had precisely the same descriptions. If the brain is dead, how can it hallucinate, or dream? let alone tens or hundreds of millions of people around the world having the exact same ones?

Guy Cohen, Los Angeles, Ca.
July 1, 2013 5:57pm

I am surprised that your criticism of NDE is so shallow. The point is not about commonality of experiences, but the fact that a) there was any experience at all b) people have been documented to give details they had no access to knowing while their brain was dead c) oxygen deprivation theory has been debunked through controlled testing d) dramatic recovery from terminal diseases after NDE etc. All of the above are tested scientifically, peer review and well documented by doctors from some of the best institutions in the world. Compared to those tests, the critics appear to be much more biased, unwilling to seriously read and question the research available and/or not domain experts. All this makes me lose faith in Skeptics! Please see for a start

SkepticalOfSkeptics, NY
August 5, 2013 9:42pm

You could have saved a whole paragrapgh of evangelising and just posted the lookey see SOS..

Molesey Dirtley, Greenacres by the sea Oz
September 3, 2013 3:40am

The problem is that other than anecdotal stories we have no controlled experimental evidence to support NDE's or OBE's. Do they really exist ? maybe. And maybe not. That is basically all we can say at this point In fact, what little controlled experimental research has been done has come up negative, indicating that NDE's and OBE's are probably not real.

joffbaum, New York, NY
November 28, 2013 12:50am

I think question should be asked is why the brain does what it does when deprived of oxygen (obe), rather than trying to debunk nde. We may get closer to an answer with actually doing the science.

Richard, Dee Why NSW Oz
January 15, 2014 2:21am

So does God make a mistake and admit people into heaven, not realizing they will be resuscitated shortly after?

I'm not being facetious, by the way. I'm truly wondering why He would do this (and only with some people).

Also, there are many beliefs that are absolutely contradictory with eachother, but each person is experiencing their own persception of the afterlife. For example, if the Christian view is correct, then everyone should be meeting Jesus and being sent to a Biblical heaven or hell. Is this the case with most NDE's?

Just curious.

Thor, San Francisco
May 5, 2014 11:32am

Thor ,
when i was a mangled heap on the road, with punctured lung from broken ribs, smashed up pelvis, legs pointing the way legs should not point, and bleeding internally from a ruptured spleen. I was in a dark place, very peaceful and no pain till the ambos revived me.
I am an atheist by the way, and more so after that experience

Bubba, Gorokan the place to be ,OZ
May 5, 2014 5:51pm

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