Well, today I got to the chapter in The Idea of the Brain: The Past and Future of Neuroscience that I was most interested in reading. (See here and here for my previous posts about the book.)
Since the author, Matthew Cobb, is exceedingly well informed about past and present history of research on the brain, I was curious what he would have to say about "Consciousness," the final chapter in the Present section of the book.
Not surprisingly, Cobb says there is no reason to doubt that the mind is material, being the brain in action, basically. Below I've shared excerpts from the chapter about this.
The first excerpt talks about split-brain patients where the corpus callosum that connects the right and left hemispheres of the brain is severed to control severe epileptic seizures. This is done rarely now, but was fairly common in 1962 when Bill Jenkins had the surgery.
Jenkins agreed to participate in what turned out to be a decades-long study by Michael Gazzaniga into how Jenkins' brain functioned after the surgery. The details are fascinating. Here's how Cobb sums them up.
These results were simply extraordinary. It was not only the brain of an animal that could be harmlessly split in two -- the same seemed to be true of a human brain, and the human mind. Each half of the brain was, on its own, sufficient to produce a mind, albeit with slightly different abilities and outlooks in each half. From one mind, you had two. Try that with a computer.
Read on for the excerpts dealing with the material nature of the mind.
The brain does not work as two separate halves, but as an integrated whole. In some way we do not understand, consciousness is unitary by nature, but it can be divided in split-brain patients, with the weird results that Gazzaniga and his colleagues have revealed. These differences between the two hemispheres strongly support the general working hypothesis that the mind emerges from the structure of the brain.
Any non-materialist explanation of the mind-brain link, like Eccle's suggestion that the brain somehow 'detects' the non-material mind, has to explain how, when separated, the two hemispheres enable such different minds to appear.
Crick's starting point was a materialist assumption that everything we feel and perceive is 'in fact no more than the behaviour of a vast assembly of nerve cells and their associated molecules'. As he emphasised, there was no absolute proof of this hypothesis (there still is not), but there is a lot more evidence in support of it than there is for any of the competing views, all of which view mind as non-material.
These amazing results contribute to the growing mountain of evidence that our conscious experiences and the activity of our brains are the same thing and suggest that, eventually, the great mystery of how it all works will be solved. As [Patricia] Churchland pointed out:
Even in this century, some philosophers have grandly announced that consciousness, for example, cannot possibly be a property of the human brain. For all the philosophical finger wagging, however, it is more than modestly auspicious that a few milliamps of current applied to the human mACC [midregion of the anterior cingulate cortex] can spawn a complex cascade of feelings, feelings that vanish with cessation of the current ... So far as anyone knows, non-physical souls do not respond to milliamps of current.
[David] Chalmers is one of several modern philosophers who have embraced non-materialist explanations of consciousness, claiming that it does not obey the physical laws of the universe, and that new laws of physics will be necessary if we are ever to understand it.
This possibility cannot be logically excluded, but at the moment there is no reason to support this view, beyond frustration at our current perplexity and the desire for something novel.
For scientists to abandon the materialist approach that has got us so far, and which provides experimental tools for investigating mysterious phenomena such as consciousness, we would need far stronger motivations, such as inexplicable experimental results that contradict the materialist working hypothesis.
No such data have been forthcoming.