Measurement Accuracy and the belief in an Afterlife

Is there an afterlife? The Lancet-published cardiologist Pim van Lommel believes there is. I believe his central statements are based on inaccurate (interpretation of) measurements.

Based on findings on Near Death Experiences (NDE) that he reported upon in the Lancet, van Lommel recently wrote a popularized book in which he explains his beliefs and research findings to a larger public. There, he argues that our consciousness is not located within our physical body. As could be expected, this book (called `Endless Consciousness’, my translation) raised a lot of discussion between ‘believers’ and ‘critics’.

But let’s take a closer look at the peer-reviewed research findings on which the statements on the afterlife are based. In the Lancet article, Van Lommel and colleagues do not speak of the existence of an afterlife, but refer to the locality of our consciousness. In an intelligent research design, van Lommel and colleagues asked hospitalized cardiac patients to participate in his research. In case these people had a cardiac arrest, from which they were successfully reanimated, these people were surveyed on whether or not they had experienced a Near Death Experience (NDE) and if so, what exactly their experiences during the NDE were.

Based on this design, Van Lommel was able to show that from the people who survived the cardiac arrest, approximately 18% had a Near Death Experience. Existing explanations on the prevalence of NDE’s, such as the religious conviction of people, the medications they used prior to the cardiac arrest, or the duration of the cardiac arrest, could all be refuted. This was done by means of cross-tabulations with the (nature of) experiences and additional information on the participants recorded prior to the cardiac arrest.

So, none of the commonly addressed alternative explanations hold. This conclusion is extrapolated to the supposed location our consciousness, which supposedly cannot be in our brain (according to the Lancet-article), and subsequently extrapolated to the existence of an afterlife (in his book). True crucial argument proposed by Van Lommel is that this is necessarily so, and not due to distorted brain functioning, because we know that during cardiac arrest the human blood pressure is too low to sustain brain functions and thereby consciousness. Thereby, the linchpin of his argument is the accuracy of the measurements on brain activity during cardiac arrest.

Although in general I do have confidence in the instruments measuring brain activity, after reading an article in a non-peer reviewed journal (Natuurwetenschap en Techniek, written in Dutch by Niki Korteweg) I recently lost my confidence in these instruments for this purpose. These measurements only give an indication of the combined pulsing of brain-cells. But there are indications that, when deprived of enough oxygen, brain cells tend to pulse randomly. That is not picked up by the measurements Van Lommel refers to. It is unknown whether or not this leads to some form of consciousness, and thereby cannot be ruled out.

Additionally, the argument that during cardiac arrest blood pressure is too low to sustain consciousness is crucial to Van Lommels statement that consciousness cannot emerge from brain-activity during cardiac arrest. However, this only holds for people in average. So, the average blood pressure is too low to sustain consciousness. However, an average comes with a standard deviation, which learns us that about 20% of the people have a blood pressure high enough to sustain some kind of consciousness, even without a heartbeat. To me, this percentage is very close to the percentage of people that had a near death experience (18%) in the Van Lommel study. So, their near death experience (I do not contest the experience they had, only its origin) is not an outside-body experience, but a result of a physical brain that basically functions but is distorted by shortage of oxygen.

There is much more to be said regarding the existence of an afterlife. However, in this case of scientific inference on this subject, I cannot but conclude that the measurement issues form an alternative explanation on near death experiences that is much more likely than the existence of an afterlife. To me, this is another example of what I recently wrote on the importance to reflect on the uncertainty that is associated with research methods, instead of building castles on loose sand.

VANLOMMEL, P., VANWEES, R., MEYERS, V., ELFFERICH, I. (2001). Near-death experience in survivors of cardiac arrest: a prospective study in the Netherlands. The Lancet, 358(9298), 2039-2045. DOI: 10.1016/S0140-6736(01)07100-8

8 comment on “Measurement Accuracy and the belief in an Afterlife

  • Umm, I can’t claim to know much about this topic, but is there any reason to think that near death experiences actually involve consciousness during cardiac arrest? I mean, sure, these people are reporting their memory of an experience which happened some time around their cardiac arrest. But presumably it takes some amount of time for blood pressure to drop, and anoxia will be happening for some amount of time after the cardiac arrest. People’s perceptions – including time perception – get heavily distorted during anoxia. How would they know when the experience happened?

  • Hi there, thank you for your comment.

    The thing is, which I indeed did not point out in my post above, is that some of the people experiencing a cardiac arrest are able to remember details of what happened during the resuscitation. According to the -blood-pressure-too-low theory, that would not be possible.

    Indeed, many of the experiences can take place when blood pressure is dropping. The tunnel and the white light is a very good example of that, for it is (possibly) due to increasing anoxia in people’s retina.

  • Hi Rense,

    I agree with you. My mother had one of those, and she told me she could actually “see” people trying to reanimate her. Anoxia has been proposed as a possible explanation for these experiences quite a long time ago, and still looks to me like the most probable explanation. In fact, there is a tiny minority of people, probably not picked up here, who had a “bad trip” – went to hell, so to speak, rather than heaven. Does this necessarily imply there is a hell?

    Many more people do not go somewhere else, they seem to “stay in one corner of the room” and observe the whole resuscitation process.
    There is only one thing all these people have in common: they have a very peculiar experience, and they all had some form of anoxia – usually, but not always, brought about by a heart attack.

    So jumping from there to the existence of paradise is a little preposterous.

    P.S. I found you through ResearchBlogging. Nice article.

  • Dear Steppen,

    thank you for sharing this personal experience, and of course for your compliment.

    I didn’t know about the existence of people having had a ‘bad trip’, but I agree with you that this indeed would not mean that people actually went to hell, or are destined to do so.

    It occurs to me that we even should be careful not to moralize the trinity of people who did not have an near death experience, had a positive experience, or a bad one. It would be too easy for some (religious?) people to argue that it has already been made up who is destined to go where after the earthly life.

    Nevertheless, as you point out in your reaction, there is much more to the occurrence of near death experiences than is covered in my post. Basically, all distinct elements have been replicated artificially, while it hasn’t been possible to replicate `full’ near death experiences.

  • Everybody goes through a tunnel. What’s so special about a tunnel? Why not up a stairway, through a door, down a corridor or a street, over a bridge, or across a river?

  • Well, of course it might just be that there actually is a tunnel. That would be a consistent explanation. However, another answer might just as well be that a tunnel is so special because it’s the way the retina dies out due to oxigen depression,

  • i cant believe the peoples comments about there not being an afterlife? its like saying if they have not had one then it cant exist. i tell all you critics now especially he that wrote the article that you have no idea what you are talking about? dr pim van lommel is an ex pert medical surgeon who has interviewed people who have had ndes, i agree totally with the doctor and when i had my nde i was dead and resurrected in the place i went to? anyway you will all find out sooner or later when you breathe your last breath. im amazed how sceptical and unbelieving some people can be? if you deny the existence of an afterlife then you deny almighty god.

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