Feb 21 2009

Mind and Brain on NPR

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NPR finally aired the segment they recorded with me last month. The segment is called Doubting Darwin: Debate Over The Mind’s Evolution, and features interviews with me and Dr. Egnor. The interviews were recorded separately – it was not a discussion or debate. Of course we are each very familiar with the other’s arguments, and readers of this blog will recognize most of the points made.

The segment was well produced and fair (at least from my perspective, I can’t speak for Dr. Egnor) – they used my points in context, chose reasonably representative segments, and did not sandbag me with counterpoints I was not aware of. (These are all risks when being interviewed, especially by lower quality outlets.)

However, there was one point that Dr. Egnor made toward the end that was not adequately addressed. He said:

“The person was able to have mental processes during a time when they were in cardiac arrest, in cardiac standstill, and sometimes even absent EEG waves. So I think there is very real scientific evidence that the mind in some circumstances can exist without a functioning brain.”

It is interesting that he never tried to make this claim in our blog debate (if he did I missed it). And of course, this claim is utterly false, and Dr. Egnor cannot produce any reference to support it – something which he essentially admits by referring to this evidence in the interview as “anecdotal”.

The segment producer added that neuroscientists claim there is still some brain activity during cardiac arrest, even if the EEG signals are hard to detect. This is true, but is only one of the two reasons why Egnor’s claim is nonsense.

Others, like Deepak Chopra, have tried to use near-death experiences as support for a mind separate from brain. I have written about his before as well. There are two reasons why NDEs are not evidence for a mind separate from brain. The first is that there is no reason to conclude that all brain activity stops during cardio-pulmonary resuscitation (CPR). CPR provides enough blood flow to the brain to keep it alive – that’s its primary function. This is enough to allow for some activity.

Also, keep in mind that EEGs are not routinely performed during CPR. It would not be feasible to place EEG electrodes on the scalp during CPR. Therefore we only see the EEG during CPR when the EEG was already in place. I am personally aware of only one case in which this occurred – the patient’s heart stopped while being EEG monitored (and it was not detected for some time, so there was no CPR). Brain waves rapidly decrease but do not instantly disappear when the heart stops. They maintain a low level of function.

In fact, there are reported cases of using bispectral index (a form of EEG that is used to monitor level of consciousness during anesthesia) to monitor the response of brain function to CPR. Effective CPR was able to maintain brain activity as measured by bispectral index – therefore the evidence suggests that CPR is capable of maintaining measurable brain function.

Generally speaking, if someone survives CPR and later recovers consciousness then it could not have proceeded for very long –  30-60 minutes at most. During this time brain activity will not have completely vanished.

So the first premise of Dr. Egnor’s anecdotal claim is not true – that there is demonstrably no brain activity during mental activity. The second premise is also not true – that the memories later reported of a near-death experience occurred during CPR, or during the time of minimal brain activity.

If someone has a sufficiently prolonged CPR that their brain activity is diminished, then it also must be true that their brain will take time to recover – hours to days. It is not like in the movies where someone comes back from cardiac arrest, their eyes flutter open and they are completely conscious. Rather, CPR survivors will slowly regain brain function and will be delirious for an extended period of time.

During this time of delirium they are forming confused memories, and have very poor time sense. It is simply not possible from any documented case to time any memory later reported by a CPR survivor to the time of their CPR – the time when their brain activity was most decreased.

Therefore, Dr. Egnor’s two necessary premises for his point – that there is no brain activity, and there is mental activity during this time – have not been established.

Of course, if this were true then Dr. Egnor would win our little debate. If there were reliable scientific evidence that the mind can exist without the brain, then the mind must be something other than just brain. But Dr. Egnor cannot make this case – if he could, he would.

Instead, he tried to slip in “anecdotal” claims during a radio interview that would not allow for a thorough exploration of his claims – claims already demolished by me and others.

So, Dr. Egnor, either provide references adequate to establish your premises or admit that there is no evidence for mind separate from brain.

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