The Parts and the Whole

For full background reading, go to William Calvin's website. Calvin is a neurologist who has made a number of his books and articles freely available on the web. You will be particularly interested in How Brains Think, in Conversations with Neil's Brain, and in his most recent book - a joint effort with linguist Dereck Bickerton - Lingua Ex Machina

We've seen that the brain is not an undifferentiated information manager - if it is at all like a computer, then we have to see it as pre-programmed. In a way, it programmes itself. But it does so rather less predictably than one would expect of a computer.

For example, most people are right-handed. This seems to be related to the fact that, for a majority of human beings, the left side of the brain is dominant - and the left hemisphere governs the right side of the body. However, as we know, some people are left-handed. Is this because their right hemisphere is dominant? Well, it is for many of them - but not for all. So there is not an altogether straightforward relationship between hemisphere dominance and handedness.

Nevertheless, some functions appear to be quite precisely linked with particular areas. For example, there is a strip that runs right across the middle of the brain, from one side to the other, and which registers the sensations in different parts of your body - you'll find a picture of this strip - the Somatosensory Cortex - in the first chapter of 'Conversations with Neil's Brain'. Each part of your body can be mapped to a different area on the strip, with the right hand side linked to the left side of the brain, and the left-hand side to the right. Just in front of this is another strip - the Motor Cortex - which is implicated in moving the different parts of the body.

But these are basic functions - and will be found in the neuro-sytem of far less complex animals than we are. Humans are capable of learning, of adding new behaviours to the basic wired-in repertoire of reflexes and instincts. These learned behaviours cannot be completely pre-programmed from the start. The more complex ones - particularly the cultural amplifiers - put in play and coordinate many of the basic functions. They are transversal skills. Language is one of these.

Recap 2 : A number of basic functions can indeed be located at given points in the brain. However, there are good reasons for thinking that language - an evolutionary late-arrival, and highly complex skill - is too flexible and overarching to be tied to one or even several discrete zones.