杏吧原创

The Unity of Consciousness: Binding, integration and dissociation edited by Axel Cleeremans, Oxford University Press, 拢35/$59.50, ISBN 0198508573 Reviewed by Steven Rose

IT has become fashionable for philosophers and scientists to fill books about this intangible process that we assume all humans share 鈥� consciousness. In the old days it was easy. We all had souls, or at least minds, and their study was the province of theologians and philosophers. Brains were the neuroscientist鈥檚 concern, who when pressed, would simply claim that consciousness was a more or less irrelevant spin-off from cerebral activity 鈥� to worry about it was to subscribe to what was contemptuously called 鈥渇olk psychology鈥�.

Simple Cartesian diagrams had inputs into the brain from sense organs plus outputs to muscles, all mysteriously coordinated by a homunculus seated at the top of the head 鈥� or perhaps in the pineal gland, where Descartes had located the seat of the soul.

But now we know there is no homunculus. The brain operates like a highly distributed anarchist collective with separate modules each doing their own thing. But we generally perceive, think and act as if 鈥渨e鈥� were an indissoluble individual. In some as yet only guessed at way, the activity of all the brain modules must be bound together to produce this sense of self.

So is consciousness unitary, and how can we solve the 鈥渂inding problem鈥�? This is the question addressed by the 22-strong ensemble who met at a consciousness conference in Brussels 3 years ago and whose ruminations are brought together in Axel Cleeremans鈥檚 collection. The book begins unpromisingly, with a tediously abstract dissection of six different forms of unity. It livens up with clinical data on brain damage and dissociation, and serious attempts to explore how binding might work. For example, the so-called 40-hertz wave is said to link the activity of the individual modules. This is the frequency at which neurons across the brain fire, setting up a rhythmic oscillation.

But in the final analysis I found this all too narrow. 鈥淓verybody knows what consciousness is: it is what abandons you every night when you fall into dreamless sleep and returns next morning when you wake up,鈥� claims the psychiatrist Giulio Tonino. Oh yes? How about the Freudian distinction between consciousness and unconsciousness? Or that of the sociologists between class, ethnic and gender consciousness? Or the novelists鈥� accounts of their creations鈥� thoughts and actions. No, my dears. Consciousness is too broad a concept, too portmanteau a term, to be left to recording electrodes and the philosophers who have taken to parasitising the physiology labs.