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Friday, October 21, 2022

An Attempt to Evade the Hard Problem

In an interesting article at Mind Matters News neurosurgeon Michael Egnor critiques an attempt by a materialist neuroscientist named Anil Seth to circumvent what philosopher David Chalmers called "The Hard Problem" of consciousness (You can watch a video featuring Chalmers discussing the Hard Problem here).

Egnor starts off by explaining what the "Hard Problem" is:
Philosopher David Chalmers famously divided the problem of understanding how consciousness is related to the brain by distinguishing between the easy and hard problems of consciousness.

The easy problem of consciousness is typically faced by working neuroscientists — i.e., what parts of the brain are metabolically active when we’re awake? What kinds of neurons are involved in memory? These problems are “easy” only in the sense that they are tractable.

The neuroscience necessary to answer them is challenging but, with enough skill and perseverance, it can be done.

The hard problem of consciousness is another matter entirely. It is this: How can first-person subjective experience arise from brain matter? How do we get an ‘I’ from an ‘it’? Compared with the easy problem, the hard problem is, from the perspective of materialist neuroscience, intractable.
By this Egnor means that the hard problem is trying to explain how electro-chemical activity in the brain is converted into sensations like the color red or the fragrance of perfume or how electro-chemical reactions in the brain give rise to a meaning when you read a page in a book.

No one knows how this happens. It's one of the deepest mysteries of the universe. If one is a dualist of one kind or another, and believes that we have an immaterial mind or soul, then perhaps this faculty is in some way involved in this mysterious translation from the physical materiality of brain function to the immaterial sensations of color or pain.

But if one is a materialist then that solution is not available to her, and so the nature of the bridge between the material and the immaterial is completely inexplicable.

One way out of the impasse is to simply deny that one's conscious experience is anything more than an illusion - what Seth calls a "controlled hallucination" occasioned by the integration of sensory inputs by the brain hemispheres.

In other words, consciousness is an illusion created by the complex interactions of the two hemispheres of the brain.

Egnor elaborates on Seth's view:
...the essence of his theory of consciousness is that the brain integrates a cacophony of sensory inputs to fabricate an explanation for perceived reality — a “controlled hallucination” — that we call consciousness.

This view, that consciousness is, in one sense or another, the consequence of massive parallel processing going on in neural circuits in the brain, is common among modern neuroscientists.

But it can’t be true.
Egnor cites two phenomena as reasons why Seth's "controlled hallucination" theory doesn't fit the facts:
...consider the neurological consequences of split brain surgery and the congenital brain condition called hydranencephaly.

In split brain surgery, neurosurgeons cut the massive bundle of nerve fibers connecting the cerebral hemispheres in order to lessen the propagation of seizures in patients with epilepsy. The two brain hemispheres are disconnected — information from one hemisphere cannot readily be transmitted to the other.

This radical disconnection of the brain hemispheres causes massive interference with the [sensory inputs that Seth posits as the source of our hallucination of consciousness] but, contrary to what Seth’s theory seems to predict, there is no impairment of consciousness whatsoever.

Patients with split brains (I have performed the surgery myself) have very subtle perceptual disabilities of which they are almost always unaware, and there is no impairment in consciousness.
Contrary to what Seth's theory would predict, despite the patient having his brain cut in half, his consciousness remains undivided and unimpaired.

An even more difficult problem for Seth's theory of “controlled hallucination” is hydranencephaly:
Hydranencephaly is a condition in which children are often born without brain hemispheres. The cause is usually a massive intrauterine stroke that destroys all of the brain above the brainstem.

Nearly all of the perceptual circuits on which Seth’s theory depends are not merely cut, but are completely destroyed, yet children with hydranencephaly are fully conscious.

I have cared for these children myself (I am a pediatric neurosurgeon). Although they are quite handicapped, they are certainly conscious, interactive, and show a full range of emotions — laughter, crying, glee, fear, and such.

Complete destruction of the cerebral hemispheres is fully compatible with consciousness.

Seth’s theory that consciousness is a “controlled hallucination” occasioned by integration of massive sensory inputs by the brain hemispheres falls apart when we consider that disconnection of the hemispheres — and even destruction of the brain hemispheres — is compatible with full consciousness (despite profound sensory and motor disabilities).
Egnor concludes that,
Only a dualist or idealist understanding of the mind–brain relationship can survive the evidence provided by split brain research and routine clinical experience with children with hydranencephaly.

The only “controlled hallucination” here is the belief that materialism can explain the mind.
As an addendum, Egnor's article includes this video of a child born with hydranencephaly and missing 80% of his brain. As the viewer can see, the child, though severely disabled, is still fully conscious:
Egnor adds this note:
Jaxon Buell (2014–2020) died at five years of age due to complications from his condition (80% of his brain missing). “Jaxon was unable to walk or talk, but his parents shared his many milestones on the now-deleted Facebook page We Are Jaxon Strong, where followers saw him smiling and appearing to communicate with noises and eye contact.” – People magazine (April 7, 2020)