In a recent discussion/debate with neurosurgeon Michael Egnor, neuropsychologist Mark Solms offers an unconventional but evidence-based view, favoring the brain stem:
In September, neurosurgeon Michael Egnor debated atheist broadcaster Matt Dillahunty at Theology Unleashed, on the existence of God. This time out (October 22, 2021), he is teamed with distinguished South African neuropsychologist Mark Solms, author of The Hidden Spring (2021) — who begins by declaring, in his opening statement, “the source of consciousness in the brain is in fact in the brain stem,” not the cerebral cortex, as almost universally assumed. He explains his reasoning with evidence.
Egnor doesn’t dispute that statement; in fact, in his own opening statement later, he reinforces it with observations from his own practice.News, “Consciousness: Is it in the cerebral cortex — or the brain stem?” at Mind Matters News
… Mark Solms: I have been led to the view, over a few decades of working in this field, that we’ve made a big mistake in our conception of consciousness in neuroscience. The mistake has a very long history, which I won’t go into, but it boils down to the view that the seat of consciousness in the brain is the cerebral cortex. This is an absolutely universal view with a very few… few exceptions, myself included, obviously.[00:03:30]
It’s our evolutionary pride and joy. But … a lot of evidence, suggests that the source of consciousness in the brain is in fact in the brain stem, which is a much more ancient, much more primitive structure that we share, not only with all other primates and all other mammals, but in fact, with all vertebrates. The basic structure of the brain stem in you and me is the same as it is in fishes. If you’re going to look at it from the physical point of view, which part of the brain, is bound up with this mental property that we call consciousness? It is the reticular activating system, in particular, of the brain stem. It’s primitive core. I said, there’s tons of evidence, but let me just mention the most dramatic bit of evidence. [00:05:00]
A very old fashioned method in neuroscience is the lesion method. Lesion is just a fancy word for damage. So, if there’s damage to a part of the brain that performs a certain function, then that function should be lost. If you apply the lesion method to this question, you find that if you damage just a tiny area of the reticular core of the brain stem, roughly two cubic millimeters in extent, in other words, the size of a match head, then the lights go out. Consciousness is lost entirely. On the other hand, there are children who are born with absolutely no cerebral cortex, a condition called hydranencephaly, and these kids are conscious. They’re conscious in the sense that they wake up in the morning, and they go to sleep at night, but more interestingly, they are emotionally responsive to their environments. [00:06:00] … More.
Takehome: The evidence shows, says Mark Solms, author of The Hidden Spring, that the brain stem, not the cerebral cortex is the source of consciousness.
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