NDE Question

[sr332603]

I've seen a lot of discussion on NDEs and read up on them a good deal. From what I can gather, a key piece of evidence proposed to prove that they represent something other than a hallucination or the brain shutting down is that they occur during periods of no measurable brain activity. (I know that this is not the only piece of evidence, but please let's keep this as the focus of this thread).

My question is - how could anyone know exactly when a dream / hallucination / experience occurred? What gives proponents a reason to believe that the experience didn't occur before or after the patient's brain activity dropped?

An analogy (and correct me where I'm wrong): If you video taped me waking up at 3:00AM to use the restroom, and the next morning I recount a crazy dream I had in the middle of the night, you would not have evidence that I was dreaming while walking around. Would you?

[David Bailey]

Originally Posted by sr332603

I've seen a lot of discussion on NDEs and read up on them a good deal. From what I can gather, a key piece of evidence proposed to prove that they represent something other than a hallucination or the brain shutting down is that they occur during periods of no measurable brain activity. (I know that this is not the only piece of evidence, but please let's keep this as the focus of this thread).

My question is - how could anyone know exactly when a dream / hallucination / experience occurred? What gives proponents a reason to believe that the experience didn't occur before or after the patient's brain activity dropped?

An analogy (and correct me where I'm wrong): If you video taped me waking up at 3:00AM to use the restroom, and the next morning I recount a crazy dream I had in the middle of the night, you would not have evidence that I was dreaming while walking around. Would you?

One piece of evidence, is that many people report specific clinical things that happened while they are being resuscitated as part of their NDE. I think that is why, the intrinsically unlikely idea that the oxygen-starved brain would suddenly boot up and create a hallucination, and remember it, ever got proposed!

David

[sr332603]

To recount, your view of the timing of these experiences rests solely on whether or not the patient is able to correctly recount the medical procedures performed on them at the time?

If that is the case, what do you do with all of the accounts where the patient does not recall any specific medical procedures?

[David Bailey]

Originally Posted by sr332603

To recount, your view of the timing of these experiences rests solely on whether or not the patient is able to correctly recount the medical procedures performed on them at the time?

If that is the case, what do you do with all of the accounts where the patient does not recall any specific medical procedures?

Well, if you establish - as I think has been done - that sometimes NDE's include these details, it seems far simpler to assume that NDE's happen when they are claimed to happen.

There is absolutely no reason to expect all people to recount such details. Imagine - you wake up dead (in effect) - think of the shock of that - different people will focus on different things.

You also have to consider two other factors. Pilots that are centrifuged to the point of blackout also report hallucinations. They are suffering the same oxygen starvation to the brain.

If people were routinely experiencing hallucinations similar to NDE's in other hospital settings, your suggestion might seem more likely.

As I mentioned in my previous response, I don't think that skeptics would have come up with the theory that the dying brain somehow manages to produce these hallucinations as it is being poisoned by excess glutamate, if your theory was an acceptable alternative.

David

[sr332603]

I guess I am just having a hard time establishing what reference point people are using for claiming when the experience happened. Presumably, if your body literally "dies" and comes back to life, there will be significant periods of sleep and confusion on either end.

I have never even tried to identify the time of night that a dream occurs because I would have no point of reference to even begin and no way to verify it after I was done (unless I was in a sleep clinic that could monitor for REM). The most I could say is "I had a dream last night." Why are NDE's any different?

Skeptics, I think, are trying to provide an explanation for the consistency of reports of NDE (the light, calm feeling, etc.) more than the timing of reports when they bring up excess glutamate. I see no reason to believe that the hallucinations of lost loved ones, conversations with god, etc. happen at the same moment as the feelings associated with a dying brain (the light, calm, peace, etc.)

[Purple Scissor]

You are right: this is one of the primary ways in which evidence in these cases is lacking. One would expect significant and unusual brain activity associated with the hallucination of NDE. I do not know whether brain waves have been monitored before, during, and after an NDE to see if there are any periods which seem anomalous and include high active in many brain regions having to do with space, sight, and emotion, and might therefore be the time when an NDE hallucination took place. If no such activity occurs before or after the period of low brain wave activity ("death"), it would be a factor in establishing that NDEs are not associated with brain wave activity.

[Paul C. Anagnostopoulos]

Originally Posted by David

You also have to consider two other factors. Pilots that are centrifuged to the point of blackout also report hallucinations. They are suffering the same oxygen starvation to the brain.

And report NDE-like experiences.

NDE - Fighter Pilot

Near Death Experience. What is it?

One piece of evidence, is that many people report specific clinical things that happened while they are being resuscitated as part of their NDE.

Some of these reports have been repudiated. The infamous shoe-on-the-window-ledge is one. I think we need some better controlled studies.

~~ Paul

[David Bailey]

Paul,

The shoe in the window question relates to the question as to whether a person undergoing an NDE has a vantage point that lets him see things he would not otherwise see. To answer sr332603's point, it is only necessary to find NDE's where people are conscious of events that definitely occurred while they were well into a cardiac arrest.

A negative result from a controlled 'shoe in window' might not mean much. I mean, imagine you discovered you had just died (!!) - maybe you would not be overly interested in details like that!

Yes, pilots report NDE-like experiences (not sure if they are identical though), but I am not sure what that proves either way.

Purple Scissor, Part of the problem is that we have all read a lot of reports of the various phenomena that interest us, but we can't necessarily put our fingers on all the references. I am pretty certain some NDE's have been reported by patients with flat EEG's at the time.

sr332603, I think when skeptics propose explanations based on excess glutamate and oxygen starvation they are implicitly accepting that these events happen when patients say they do. The studies of pilots also indicate that something odd happens at this point - but presumably pilots can't be taken as far down that path!

My sense is that skeptics use two explanations for NDE's, neither of which covers all the facts.

1) Dying brain hypothesis.

2) Maybe NDE's happened at a different time.

I wish they would pull this together and accept that relying on two different explanations is less convincing!

Really, we are back to the core problem. If you set the prior probability of non-material consciousness to a sufficiently small number, any old combination of alternative hypotheses seems preferable! You can actually play with the maths for this - just look up Bayes theorem, and put in a prior probability of 0, and see what happens!

David

[Paul C. Anagnostopoulos]

Originally Posted by David

The shoe in the window question relates to the question as to whether a person undergoing an NDE has a vantage point that lets him see things he would not otherwise see. To answer sr332603's point, it is only necessary to find NDE's where people are conscious of events that definitely occurred while they were well into a cardiac arrest.

But not events like "the doctor was leaning over me" or "people were talking about my blood pressure."

Yes, pilots report NDE-like experiences (not sure if they are identical though), but I am not sure what that proves either way.

Well, if you agree that the pilots are not near death, then it demonstrates that NDEs don't require near-death.

sr332603, I think when skeptics propose explanations based on excess glutamate and oxygen starvation they are implicitly accepting that these events happen when patients say they do. The studies of pilots also indicate that something odd happens at this point - but presumably pilots can't be taken as far down that path!

Perhaps some happen during the flatline and others are conflations of things that happened at other times.

1) Dying brain hypothesis.

2) Maybe NDE's happened at a different time.

I wish they would pull this together and accept that relying on two different explanations is less convincing!

It may be less convincing to you, but why should I think that a single explanation is required? Is there a single explanation for any other physical abnormality?

Really, we are back to the core problem. If you set the prior probability of non-material consciousness to a sufficiently small number, any old combination of alternative hypotheses seems preferable! You can actually play with the maths for this - just look up Bayes theorem, and put in a prior probability of 0, and see what happens!

And if you set it sufficiently high, you'll believe all manner of nonsense. Since we don't know the probability, I guess we have to do some work.

~~ Paul

[FastEddieB]

...it is only necessary to find NDE's where people are conscious of events that definitely occurred while they were well into a cardiac arrest.

Let me add, "that are beyond what chance might predict".

What I mean is, there may be thousands and thousands of NDE's, the vast majority of which are trivial, or lacking (or just plain wrong) in detail. If you sift through ALL NDE reports (and I'll assume the majority of mundane ones don't even get reported) and just pick out the handful that are "interesting", I think you are bound to come up with isolated cases that seem remarkable.

Its all very interesting, but I remain unconvinced.