I heard a report on the radio about a new idea in American politics – brain scanning. From scans of people’s brains political scientists hope to be able to find out their views, opinions, wishes, perhaps their prejudices. In the report a British political commentator gave his response.
It could not work, he said, because people deliberately make choices which go against what their brain looks as though it is doing. If, for example, it were possible to read from someone’s brain that they desired chocolate, that person could deliberately act against that tendency and do the opposite. For this reason, he claimed, the whole notion of brain scanning to predict behaviour was doomed to failure.
I do not know whether or not at some time in the future it will be possible to scan brains and to find in them neural correlations to political views and attitudes. It may be or it may not be. In principle, if the correlations are shown to be regular, it seems at least feasible.
But what is perhaps more interesting and revealing is the response of the critic of the idea. For if there is a brain state that corresponds with my desire for chocolate and I were to make a choice to deny myself the chocolate, how would I go about it? I might, for example, have a strong desire also to maintain a no-chocolate diet. But if the desire for chocolate is represented by a brain state, is it not very likely that my desire to keep to my diet is also represented by a brain state? Presumably, that brain state will appear on the brain scan too?
How is it we can believe that the brain corresponds to some of our mental states and not to others?
Consciousness and Other Matters 