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Saturday, October 13, 2012

Sam Harris on a NDE as drug trip

I wrote this week about Eben Alexander's account of his must-be-true experience with the afterlife, which made the cover story in Newsweek. Now I see Sam Harris has weighed in on the topic, and he definitely has opinions. First, he incredulously asks how a neurosurgeon could deliver such an account:
Everything—absolutely everything—in Alexander’s account rests on repeated assertions that his visions of heaven occurred while his cerebral cortex was “shut down,” “inactivated,” “completely shut down,” “totally offline,” and “stunned to complete inactivity.” The evidence he provides for this claim is not only inadequate—it suggests that he doesn’t know anything about the relevant brain science. Perhaps he has saved a more persuasive account for his book—though now that I’ve listened to an hour-long interview with him online, I very much doubt it. In his Newsweek article, Alexander asserts that the cessation of cortical activity was “clear from the severity and duration of my meningitis, and from the global cortical involvement documented by CT scans and neurological examinations.” To his editors, this presumably sounded like neuroscience. 
The problem, however, is that “CT scans and neurological examinations” can’t determine neuronal inactivity—in the cortex or anywhere else. And Alexander makes no reference to functional data that might have been acquired by fMRI, PET, or EEG—nor does he seem to realize that only this sort of evidence could support his case. Obviously, the man’s cortex is functioning now—he has, after all, written a book—so whatever structural damage appeared on CT could not have been “global.” (Otherwise, he would be claiming that his entire cortex was destroyed and then grew back.) Coma is not associated with the complete cessation of cortical activity, in any case. And to my knowledge, almost no one thinks that consciousness is purely a matter of cortical activity. Alexander’s unwarranted assumptions are proliferating rather quickly. Why doesn’t he know these things? He is, after all, a neurosurgeon who survived a coma and now claims to be upending the scientific worldview on the basis of the fact that his cortex was totally quiescent at the precise moment he was enjoying the best day of his life in the company of angels. Even if his entire cortex had truly shut down (again, an incredible claim), how can he know that his visions didn’t occur in the minutes and hours during which its functions returned?
Then he wonders, as I wondered, how Alexander didn't even consider the possibility that he was just experiencing a really intense high:
Alexander believes that his E. coli-addled brain could not have produced his visions because they were too “intense,” too “hyper-real,” too “beautiful,” too “interactive,” and too drenched in significance for even a healthy brain to conjure. He also appears to think that despite their timeless quality, his visions could not have arisen in the minutes or hours during which his cortex (which surely never went off) switched back on. He clearly knows nothing about what people with working brains experience under the influence of psychedelics. Nor does he know that visions of the sort that McKenna describes, although they may seem to last for ages, require only a brief span of biological time. Unlike LSD and other long-acting psychedelics, DMT alters consciousness for merely a few minutes. Alexander would have had more than enough time to experience a visionary ecstasy as he was coming out of his coma (whether his cortex was rebooting or not). 
Does Alexander know that DMT already exists in the brain as a neurotransmitter? Did his brain experience a surge of DMT release during his coma? This is pure speculation, of course, but it is a far more credible hypothesis than that his cortex “shut down,” freeing his soul to travel to another dimension. As one of his correspondents has already informed him, similar experiences can be had with ketamine, which is a surgical anesthetic that is occasionally used to protect a traumatized brain. Did Alexander by any chance receive ketamine while in the hospital? Would he even think it relevant if he had? His assertion that psychedelics like DMT and ketamine “do not explain the kind of clarity, the rich interactivity, the layer upon layer of understanding” he experienced is perhaps the most amazing thing he has said since he returned from heaven. Such compounds are universally understood to do the job. And most scientists believe that the reliable effects of psychedelics indicate that the brain is at the very least involved in the production of visionary states of the sort Alexander is talking about. 
I hadn't realized that Alexander was writing, or has already written, a book on this experience. I imagine that books describing the author's trip to the celestial afterlife do much better than books describing the author's really amazing drug trip, but that's just a hunch.

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