Summer is here and I have finally started on my summer reading list. First up was Michael Gazzaniga’s new book The Consciousness Instinct. Gazzaniga is of course we’ll known for his work on split brain patients and for helping to found the the discipline of cognitive neuroscience. I was very excited to read the book but after having done so I am very disappointed. There are some interesting ideas in the book but overall it does not strike me as a serious contribution to the study of consciousness.
The book begins with the standard potted history of the mind body problem with Descartes invoked as the primary villain. It was Descartes who initiated the-brain-is-a-machine ethos and Gazzaniga thinks that is a mistake. This part of the book was well written but could be found almost anywhere. He then goes completely off the rails and invokes quantum mechanics as a non-mechanical foundation for solving the mind-body problem. In particular he invokes the notion of complementarity as his solution. According to him Quantuum mechanics tells us that a physical system can be in two different states at once (p. 175). So the brain can be a mechanical system and also a mind at the same time. No problem.
I am of course no expert on quantuum mechanics (though I have put it in a fair amount of time trying to figure it out). But as far as I understand it this is a gross misuse of the idea of complimentary. Quantum mechanics does not say that a physical system can be in two contradictory states at the same time! Rather what it says is that the state of the system *before measurement* cannot be described by classical concepts like ‘wave’ or ‘particle’ yet once a measurement is made (and depending on the type of measurement we make) we will find that it does have one of these properties (and had we done the measurement different we would have found that it had the other property). How, then, should we think of poor Schrodinger’s cat? Isn’t the poor cat both dead and alive (as Gazzaniga says on p. 181)? Not as I understand it! When we have a vector, represented by |A> and we add it to another vector |B> then, yes, we do get a new vector that represents the state the system has entered but saying that 1/2|Alive> + 1/2|Dead> represents the cat’s state before measurement doesn’t mean it is both dead AND alive; it means that when we measure it it will EITHER be dead OR alive (with probabilities given by the 1/2).
But what about before we measure it? What state is the cat in then? As far as I understand it quantum mechanics (i.e. the mathematical formalism) is silent on that question but the reply I prefer is that the cat has no determinate properties before the measurement.
But all of this is highly controversial and does not help us at all with the mind-body problem! Suppose, as Gazzaniga assumes, that the mind and brain are two irreducible complimentary descriptions of the single system, then we would only be able to know (i.e. measure) one of the at a time, at the expense of the other. But that is manifestly not the situation. We can measure our own brain activity even as we are having conscious experiences produced by/identical with that neural activity. No complementarity required.
I am leaving out a lot of the details, and as I said some of his views are interesting, but what is it about consciousness that drives people to these kinds of extreme intellectual gyrations? Why do people trust their intuitions so much that they are ready to jettison all of the progress made by psychology and neuroscience as wasted time?