Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.

Tuesday, August 15, 2023

Out of your mind

One of the most striking pieces from neuroscientist David Eagleman's brilliant TED Talk "Can We Create New Senses for Humans?" centers around what is really happening when we experience something.

Regardless what it feels like, all that's going on -- the internal reality, as it were -- are some fairly weak voltage changes bouncing around in the brain.  The brain is locked inside the skull, and on its own is blind and deaf.  It needs the sense organs (Eagleman calls them our "peripherals") to send electrical signals in via input nerves to the right places in the brain, and that stimulates changes in the voltage in those areas.

That's it.  Everything you've ever experienced -- good and bad, pleasant and unpleasant -- boils down to that.  And if something messes around with any step in that process, that altered electrical state in the brain becomes the basis of what you see, hear, feel, and think.  If the wiring is faulty (thought by some researchers to be the cause of the peculiar disorder synesthesia), if there's a problem with the levels of neurotransmitters, the chemicals that either pass signals along or else block them (probably involved in schizophrenia, depression, and anxiety, among others), or if you've taken drugs that change the electrical activity of the brain -- that becomes your reality.

I was reminded of this sobering observation when I read an article sent to me my a friend and loyal reader of Skeptophilia.  Entitled, "Have Scientists Found the Source of Out-of-Body Experiences?", it describes research into a part of the cerebrum called the anterior precuneus, which appears to be involved in our sensations of conscious awareness.  Neuroscientist Josef Parvizi of Stanford University was working with epilepsy patients who were experiencing drug-resistant seizures, and found that when the anterior precuneus was electrically stimulated (the patients already had electrodes implanted in their brains to try to reduce the frequency and severity of their seizures), they had sensations of floating, and of dissociation and disorientation.

"All of them reported something weird happening to their sense of physical self," Parvizi said in an interview in Scope, Stanford Medicine’s blog.  "In fact, three of them reported a clear sense of depersonalization, similar to taking psychedelics."

Luigi Schiavonetti, The Soul Leaving the Body (1808) [Image is in the Public Domain]

What it made me wonder is if the anterior precuneus might be involved in other types of dissociation.  It's one thing when you artificially trigger a part of the brain to malfunction (or at least, alter its function) using electrodes or chemicals; but what about when it just kind of... happens?  I know I've had this experience while listening to music.  When I was about twelve, my grandma gave me a little portable radio, and I listened to it constantly.  One evening, I happened upon a radio station playing classical music, and just as I tuned in, I heard the wild, joyous trumpets and violins of the overture to J. S. Bach's Magnificat in D.

Then the chorus came in.

Three minutes later, I remembered where (and who) I was.  My face was wet with tears.  I don't know where I'd been during that time, but it wasn't in my attic bedroom in my grandma's house, with its creaky wood-plank floors and pervasive smell of dust and old books.

It was such a powerful and overwhelming event in my life that I wrote it into one of my novels, The Hand of the Hunter -- with setting and character changes, of course -- but to this day when someone says they had a "spiritual experience," this is what I think of.  It's happened to me more than once since then, always associated with music (the first hearings of Ralph Vaughan Williams's Fantasia on a Theme by Thomas Tallis, Stravinsky's Firebird, Debussy's The Drowned Cathedral, Arvo Pärt's Spiegel im Spiegel, and Mozart's Requiem had similar effects on me), but that first encounter was by far the most striking.

I wonder if the mental and physical sensations that accompanied it had something to do with the anterior precuneus?  And if, by extension, it might be the source of all such transcendent experiences?

If so, what possible purpose could this serve?

Figuring that out is considerably above my pay grade, but considering the similarities -- a loss of awareness of where your body is, dissociation, the feeling of a "time slip" -- it did bring the question up.

In any case, finding a part of the brain that, when stimulated, it makes you lose connection to the outside world is pretty staggering.  I recall one of my mentors Cornell University Professor Emeritus Rita Calvo (of the Department of Human Genetics) saying that if she were going into biology today, she'd choose neuroscience instead of genetics.  "With respect to the brain, we're right now where we were with the gene a hundred years ago.  We have an idea of some of the 'wheres' and 'hows,' but little understanding of the mechanisms behind them.  Think of what was on the horizon for geneticists in 1923 -- that's what the neuroscientists have to look forward to."


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