Peter Holmes wrote: ↑Thu Feb 17, 2022 8:09 pm
Can there be natural non-material causation?
Well, I think so, obviously.
I'd like to know why he thinks 'the dualist hypothesis' seems the more reasonable.
You could read the book...
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Pioneering Neuroscientist Wilder Penfield: Why Don’t We Have Intellectual Seizures?
Michael Egnor
Penfield was a pivotal figure in modern neurosurgery. He was an American-born neurosurgeon at the Montreal Neurological Institute who pioneered surgery for epilepsy. He was an accomplished scientist as well as a clinical surgeon, and made seminal contributions to our knowledge of cortical physiology, brain mapping, and intraoperative study of seizures and brain function under local anesthesia with patients awake who could report experiences during brain stimulation.
His surgical specialty was the mapping of seizure foci in the brain of awake (locally anesthetized) patients, using the patient’s experience and response to precise brain stimulation to locate and safely excise discrete regions of the cortex that were causing seizures. Penfield revolutionized neurosurgery (every day in the operating room I use instruments he designed) and he revolutionized our understanding of brain function and its relation to the mind
Penfield began his career as a materialist, convinced that the mind was wholly a product of the brain. He finished his career as an emphatic dualist.
During surgery, Penfield observed that patients had a variable but limited response to brain stimulation. Sometimes the stimulation would cause a seizure or evoke a sensation, a perception, movement of muscles, a memory, or even a vivid emotion. Yet Penfield noticed that brain stimulation never evoked abstract thought. He wrote:
There is no area of gray matter, as far as my experience goes, in which local epileptic discharge brings to pass what could be called “mindaction”… there is no valid evidence that either epileptic discharge or electrical stimulation can activate the mind… If one stops to consider it, this is an arresting fact. The record of consciousness can be set in motion, complicated though it is, by the electrode or by epileptic discharge. An illusion of interpretation can be produced in the same way. But none of the actions we attribute to the mind has been initiated by electrode stimulation or epileptic discharge. If there were a mechanism in the brain that could do what the mind does, one might expect that the mechanism would betray its presence in a convincing manner by some better evidence of epileptic or electrode activations.
Penfield noted that intellectual function — abstract thought — could only be switched off by brain stimulation or a seizure, but it could never be switched on in like manner. The brain was necessary for abstract thought, normally, but it was not sufficient for it. Abstract thought was something other than merely a process of the brain.
Penfield’s observations bring to light a perplexing aspect of epilepsy — or at least an aspect of epilepsy that should be perplexing to materialists. Seizures always involve either complete unconsciousness or specific activation of a non-abstract neurological function — flashes of light, smells, jerking of muscles, specific memories, strong emotions — but seizures never evoke discrete abstract thought. This is odd, given that the bulk of brain tissue from which seizures arise is classified as association areas that are thought to sub-serve abstract thought. Why don’t epilepsy patients have “calculus seizures” or “moral ethics” seizures, in which they involuntarily take second derivatives or contemplate mercy? The answer is obvious — the brain does not generate abstract thought. The brain is normally necessary for abstract thought, but not sufficient for it.
Furthermore, Penfield noted that patients were always aware that the sensation, memory, etc., evoked by brain stimulation was done to them, but not by them. Penfield found that patients retained a “third person” perspective on mental events evoked by brain stimulation. There was always a “mind” that was independent of cortical stimulation:
The patient’s mind, which is considering the situation in such an aloof and critical manner, can only be something quite apart from neuronal reflex action. It is noteworthy that two streams of consciousness are flowing, the one driven by input from the environment, the other by an electrode delivering sixty pulses per second to the cortex. The fact that there should be no confusion in the conscious state suggests that, although the content of consciousness depends in large measure on neuronal activity, awareness itself does not.
Penfield finished his career as a passionate dualist. His materialist naiveté did not survive his actual scientific work and his experiences as a clinical neurosurgeon. My own experience as a neurosurgeon has led me to the same conclusion.
Remarkably, scholastic philosophers who worked in the Aristotelian tradition presaged Penfield’s observations centuries ago. In the classical Aristotelian-Thomist understanding, the mind is several powers of the soul, which is the subsistent form of the body. “Subsistent” means that the soul informs the body, so to speak, as any form is composed to matter, but that it can exist independently of matter. The reason it can exist independently of matter is that the intellectual powers of the soul — the ability to contemplate universals and engage in abstract thought — is necessarily an immaterial power. Universals — concepts that are not particular things — by their nature cannot be in particular things, and thus cannot be in matter, even in brain matter.
Thus, the mind, as Penfield understood, can be influenced by matter, but is, in its abstract functions, not generated by matter.
Aristotle, if informed of Penfield’s experiments, would have yawned: “Of course the mind is not wholly material. Abstract thought — contemplation of universals — is immaterial by its nature, and cannot be generated by the brain.” The philosopher would have shrugged, as he concerned himself with other propositions that weren’t as obvious. It is remarkable that insights from philosophers in the Aristotelian-Thomist school from millennia ago presage modern discoveries in the neuroscience of the mind-brain relationship with such stunning accuracy.
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From
Interdisciplinary Neuroscience
Wilder Penfield, a neurosurgeon and a dualist
Wilder Penfield (1891-1976), a neurosurgeon and a dualist, says that the fact that human consciousness can study its own brain and the content of consciousness contradicts, in principle, the logic of all material world. As soon as we start studying our own biological organism and get aware of the content of our own consciousness, we stop being biological species like other animals.
Penfield operated and treated epileptic patients. While operating or examining the altered portions of brain in which the epilepsy-producing discharge began after electrical stimulation, he preferred to speak with his patients and ask what they felt or thought when he touched the brain. The patients preserved the consciousness throughout the procedure and helped to identify the altered portion of the brain. The brain itself is not sensitive and cannot give rise to pain. Penfield used only local analgesic injected into the scalp before making the incision (Penfield, 1975). Penfield comes to the conclusion that in the brain there is the place of the highest integration of consciousness and body, and this place is not in neocortex, as all think, but in the upper part of the brain stem - diencephalon. He actually discovered two important brain mechanisms in the diencephalon: (1) the highest brain-mind mechanism, which is essential to the existence of consciousness, and (2) the automatic sensory-motor mechanism (a “computer”), which is essential to the sensory-motor coordination. It is important in what place an epileptic discharge occurs and where it goes. “When an epileptic discharge occurs in the central cortex in any of the sensory or motor areas, and if it spreads by bombardment to the higher brain-stem, the result is invariably a major convulsive attack, never, in our experience, an attack of automatism. On the other hand, as mentioned above, a local discharge in prefrontal or temporal cortex may develop into automatism” (Penfield, 1975: 40). In other words, if the first mechanism in the diencephalon (the highest brain-mind mechanism) is damaged by epileptic discharge coming from the prefrontal, or temporal cortex, the human automation replaces conscious behaviour, and the man is incapable of admiring the beauty of nature, experiencing happiness, love and compassion because “the automation is a thing that makes use of the reflexes and the skills, inborn and acquired, that are housed in the computer”) (Penfield, 1975: 47). The person may wander about aimlessly, go home, or drive a car, but he has a complete amnesia what he has been doing. Penfield’s description of human mindless automation sounds like Descartes’ automaton, i.e. a human body without a spiritual/mental substance.
Penfield describes an interesting episode from his practice. His patient suffered from epileptic attacks, and the discovered area was very close to the major speech area. In order to avoid a mistake during the forthcoming operation, which could cause permanent aphasia, Penfield tried to find the exact speech area and touched the brain with a stimulating electrode. The brain is not sensitive, and the patient did not realize what made him speechless (the electrode had touched the special spot and thus had blocked the speech ability). The patient was shown a picture of a butterfly and was asked to give the name of it. The patient could not. “Then he snapped his fingers as though in exasperation. I withdrew the electrode and he spoke at once” (Penfield, 1975: 52). The patient said, “Butterfly”, and added that he could not get that word “butterfly”, so he had tried to substitute it with the word “moth”, but failed. The patient could not speak, but he understood what was in the picture, i.e. a non-verbal concept of a “butterfly”. He did not understand why he could not pronounce “butterfly” and turned to another similar non-verbal concept “moth” at his will, and his mind approved the choice, but he could not pronounce a new word again because the speech area was still blocked. The patient called on two brain-mechanisms alternately and at will (Penfield, 1975: 52).
A lot is done automatically and with the help of reflexes by the man, but what the mind does cannot be explained by any neuronal work and neuronal mechanisms as Penfield concludes. He supposes that the mind has its own energy, and this energy differs from the energy of neurons. The mind directs the brain, and the highest brain-mind mechanism performs the role of a messenger, connecting mind with brain (Penfield, 1975).
When Penfield made another patient move his hand because he touched a certain place in the motor area of the cortex by an electrode, the patient said that it was not him who moved the hand but it was the doctor, who forced him to do it.
Penfield arrives at the conclusion that it is impossible to find any place in the brain where electrical stimulation makes the man believe that he did the action at his own will or find the place the touch of which makes the man take decisions (Penfield, 1975: 76).
In the end, Penfield had to admit the existence of two independent and interacting substances, “For my own part, after years of striving to explain the mind on the basis of brain-action alone, I have come to the conclusion that it is simpler (and far easier to be logical) if one adopts the hypothesis that our being does consist of two fundamental elements” (Penfield, 1975: 80).
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