Friday, May 27, 2011

Critical examination of the Near Death Experience, Part One

A book by Jeffrey Long, M.D., with writer Paul Perry, entitled Evidence of the Afterlife, has been a bestseller. It is a book about Near Death Experiences, which many people, including the authors, claim to be evidence of life after death. I have read about Near Death Experiences for many years, and am very skeptical that they are manifestations of an afterlife, despite the fact that I would like to believe that they are. For some of you, it is important to know whether these experiences reveal the existence of an afterlife; for all of us, it is an interesting example of how to apply the scientific method to phenomena that involve the human brain.

This subject is, of course, relevant to evolution for two reasons. First, if they truly are glimpses into heaven, then science is a deficient way of understanding the human experience, even though it may be a perfectly adequate way of explaining atoms and cells and organisms. Second, if Near Death Experiences are not mere delusions, then evolution has to explain them somehow. It is also interesting from the viewpoint of the process of scientific thought: how can you examine such a subject, while avoiding bias?

A Near Death Experience (NDE) may occur when a victim or patient begins to die, or actually dies, usually under medical care, and then returns to life. When they return to consciousness, they may report that they have had an intense experience that they usually interpret as seeing into the afterlife, in which the souls of dead people still live. There are certain stereotypical experiences that are very common in NDEs, including the following:

• Bliss. Most NDE are blissful experiences.
• The Comforting Presence. The person experiences the presence of a powerful spiritual being who leads them through the NDE, and does not pass judgment on them.
• The Life Review. The person sees a movie-like rerun of the events of their lives.
• Out of Body Experience. The person reports seeing themselves lying unconscious or dead, and sees medical or other personnel attempting to revive them.
• The Tunnel. The person progresses through a tunnel toward a bright and welcoming light.

It is obvious that Long and Perry have a bias: their purpose is to convince you that the victims or patients are actually seeing or entering into a real afterlife; that is, the experiences are not merely occurring within their brains. It cannot be denied that, if this is true, it is one of the most significant facts in the world, and the authors’ enthusiasm would be justified. However, their enthusiasm leads them to make critical errors in interpretation and analysis, errors that may or may not be fatal to the belief that NDEs are visions of the afterlife.

One piece of evidence that the authors are not being objective is that they do not consider or present credible alternative interpretations. Instead, they use straw men as their alternative hypotheses. For example, their logic seems to be that if an NDE is not a hallucination then it must be a vision of the afterlife. In fairness it must be added that some of their careless critics have created these straw men for them. But this is no more convincing than a Tea Partier claiming to be correct because a Communist is wrong. In these blog entries, I intend to develop an alternative interpretation.

The authors also reveal their bias by also entirely omitting any mention of the evidence that connects the elements of NDEs to stimulation of the right temporal lobe and by the drug ketamine. Stimulation of the right temporal lobe, either by a medical occurrence (stroke or epilepsy) or by experimental induction (Persinger’s famous God Helmet) produces some, though not all, of the characteristics of NDEs. It is clear that an NDE is not merely a delusion produced by epilepsy or brain chemicals, but it appears to be partly so, and the authors could at least have mentioned this evidence.

We must admit that NDEs are no mere delusions brought on by lack of oxygen (due to cessation of blood flow to the brain) or other trauma. NDEs differ significantly from delusions experienced by living people.

• They are vivid and clear. The emotionally-charged clarity of an NDE is usually strong enough to change the life of the person who experiences it.
• They are nonrandom. They contain some of the elements listed above, and usually very little else.
• They contain experiences that are difficult (the authors claim impossible) to explain in scientific terms.

The vividness and emotional power of NDEs also distinguish them from dreams. The authors claim that people dream about those whom they have recently encountered, while NDE include visions of people who are dead. The authors are incorrect about what they say about dreams; the very night before I read their book, I had dreamed of two people of whom I had not recently thought and to whom I had no particularly strong connection. But it is fair to note that NDEs contain visions of a nonrandom set of people: dead family members, even those that they did not know where dead.

Among the experiences that are difficult to explain are the following examples. One victim reported overhearing a conversation that occurred outside of the hospital room down the hall. Another reported that, while he was in a coma, someone had brought a candle and left it in a drawer; he was able to tell the nurse which drawer it was in. Another man knew which drawer his dentures had been placed in. A woman reported meeting a grandmother who had died before she was born, and she did not know who it was until, later, she saw a photograph of this grandmother. Perhaps the most interesting of all was the woman who reported seeing a shoe on a window ledge that she could not have seen from her room (page 73). It would seem impossible for a person in a coma to actually see and know things that occurred during the coma.

Nevertheless, there are alternative explanations, though not easy ones. These observations cannot be brushed off as mere delusions. How could someone know what was going on while they were in a coma? We know of no way this could happen. But it is possible that people experiencing an NDE do, in fact, have some kind of perception of what is going on around them, a modality of perception that is not merely seeing or hearing. A person in a coma cannot see which drawer a candle or a set of dentures is placed, but may sense it in some way we do not yet understand and which a coma does not inhibit. This opens up new possibilities for research; the ability of the human body to perceive stimuli, and transmit them to the brain, may be much greater than we had thought. But this does not prove that the victim was seeing into the afterlife. In fact, the best description of what might be happening was provided in the authors’ own words. In Chapter 8 they write, “It is a unique and remarkable state of consciousness.” And on page 201, they write, “…there is far more to consciousness and memory than can be explained solely by our physical brain. I find that incredibly exciting.” I think the authors are right about this and wrong about NDEs being visions into the afterlife.

Some of the other experiences can be explained by the ability of the brain to deceive itself. The woman who “saw” the grandmother who had died before she was born may in fact have seen a photograph of her years earlier, and had forgotten about it consciously. The woman who saw the shoe on the ledge may have seen it while being wheeled down the hall (the shoe was, after all, beside a window) and then forgotten it. The people who had visions of these things were not lying; they may have simply forgotten what they had seen at a previous time. We’ve all been there.

I conclude this first entry about Long and Perry’s book with this tentative conclusion: people who experience NDE are having a unique and vivid kind of mental experience, into which is incorporated things they have previously seen or that they have perceived during their comas in a manner not yet understood. There is no reason to conclude that they are seeing into the afterlife. In fact, as described in later entries, there are reasons to suspect that they are not.


  1. I find it terribly disturbing that many of religious faith use NDEs as proof that the afterlife exists. There is too much for us to probe/understand about NDEs before any of them can come to such an unsubstantiated conclusion.

  2. I look forward to your continuing discussion. I have not had my own NDE. I am open-minded to be convinced out of thinking that NDEs are a window to a living consciousness that does not depend on our physical bodies for survival (aka afterlife). If NDEs do not provide a temporary visa into an afterlife or other alternative reality experience, one would want to ask why so many NDErs emerge absolutely not afraid of death anymore. Why are they so unified in their conviction?

    In my blog I have been wondering aloud why the requisite brain scientist in NDE documentaries and news reports just seem to be there to say "it's all in the brain." Why aren't they jumping up and down and saying, "This is incredibly exciting stuff and we should be researching how the brain does this."

    Whether it's a window into the afterlife or not, some very intriguing stuff is going on.

  3. This is always a fascinating subject. I try to remain unbiased, but unlike so many scientific questions, the possibility of the OBE/NDE phenomenon being just what it appears to be--evidence of mind/body separation--has consequences for all of us.

    Regarding the experimentation that's been done with ketamine and right temporal lobe stimulation, I would love to see such a study done on those who've had a natural OBE/NDE. I recall reading at least one instance where this was done, and the subject said that the ketamine's effect was like a hallucination and nothing like his OBE. (I'm not sure that such experiments necessarily disprove the idea of consciousness existing independently of the body, though. Putting spiritual mumbo-jumbo aside, if so-called "remote viewing" can be demonstrated by an induced OBE, it could be argued that the OBE is a literal and naturally-occurring phenomenon.)