Neurophilosophy

What are the connections between research in neuroscience and issues in medicine? What may be the underlying cause of schizophrenia? How did we learn the role the hippocampus plays in learning? These and other questions are answered by UC President’s Professor of Philosophy Emerita at the University of California, Patricia Churchland.

Neurophilosophy is kind of at the interface between neuroscience on the one hand and those grand old questions that have worried philosophers for a long time. So the idea is that: because science has developed so much and because neuroscience is really beginning to develop in rather extraordinary ways – the idea was that there would be things from neuroscience, particular kinds of discoveries that would help us understand things about the nature of the mind, and on the assumption that our mental states and our capacity for learning and remembering, for seeing, for thinking – that all of these are functions of the physical brain. The idea really that motivated neurophilosophy was that we will understand those functions much more deeply once discoveries are made in neuroscience that bear upon them. And this has kind of turned out to be so. So let me give you an example of what in the early days kind of motivated me to think that to understand the mind you need to understand the brain.

So the discovery that really motivated me, I think, was the discovery made in California at Caltech that in human patients who were treated for epilepsy surgically a very remarkable result was observed. These are known as the split brain patients. So they were epileptic, but their epilepsy could not be treated by drugs. So what happened was: surgeons suggested that if you separated the two cerebral hemispheres, the right from the left, that this might have the good effect for the patient of controlling the seizure. So what they did was they separated the two hemispheres by cutting the nerve sheet that normally in us connects the two hemispheres and that keeps information on this side sent to information on this side and vice versa. The deeper structures were not, of course, split. So it was really just at this upper level where the cortex connects. The result was that in a way consciousness was split.

How can the brain be so amazing? How can its elements be so much slower than the elements of a computer, by a factor of a thousandfold, and yet we can do things much faster? So we knew that there is a lot of parallel processing, and the idea that a parallel machine with the kind of organisation of nervous systems might be amazingly efficient, much more so than the kind of conventional computers, that are pretty darn amazing in themselves. So there may be tremendous technological spin-offs also from neuroscience. And this is a reason that has motivated many governments to invest very heavily in neuroscience, not just for health reasons, not just because the questions are scientifically so exciting, but also because it may open the door to conceptually very, very new ways of computing and doing the kinds of things that we would like machines to have the flexibility and the complexity in order to be able to do.