Read My Year Off for Free Online Page B

unable to recognize the world in which he or she finds himself. For such people, their world, as Pinker puts it, ‘is like handwriting they cannot decipher. They copy a bird faithfully but identify it as a tree stump. A cigarette lighter is a mystery until it is lit.’
    The remaining 85 per cent of strokes are caused by the partial or complete blockage of an artery, either by the local narrowing and eventual blockage of an artery caused by clotting, or by the sudden arrival of a clot from elsewhere in the body (i.e. from an artery in the neck, or from a chamber in the heart) and thereby resulting in the cutting off of the blood supply — and the death of brain cells — to an organ as dependent on the blood supply as the heart and lungs are on oxygen. The main cause of arterial blockage is the deposit of fatty substances in the wall of the blood vessel. This results in stenosis (narrowing); occlusion (blockage); or embolism (the formation of a blood clot on the damaged arterial wall). This ‘cerebrovascular disease’ is often linked to the degeneration of arteries elsewhere in thebody, especially the heart. The main causes of arterial wall damage leading to narrowing and blockage are, first, high blood pressure and second, the accumulation of fat in the vessel wall. Of these, high blood pressure is far more important. This goes some way to explaining why, as a patient during these months, I found virtually every member of the medical profession I met for the first time wanting to take my blood pressure.
    If the causes of my stroke were obscure, the effects were clear enough, and occupied a great deal of my attention. In the months after my stroke, I became fascinated by the workings of the brain and used to meet regularly with a subtle and delightful Irish neuro scientist, Professor Ray Dolan of the Wellcome Department of Cognitive Neurology, at the Institute for Neurology in Queen Square, who gave me a series of informal seminars in the mechanics of the brain, so far as they are known today. Within the field of neuroscience, the Institute is a state-of-the-art organization researching a subject that is still very much in infancy. Waiting one day in the high-tech minimalist foyer of the Wellcome building, I was amused to note a beguilingly frank advertisement for a forthcoming seminar: ‘The functional organization of working memory processes within the lateral frontal cortex — do we know anything yet?’
    Dolan explained that the brain consumes 25 per cent of the energy production of the body. ‘It is as if the body is a slave to the brain,’ he told me. ‘The extraordinary thing about the brain is that while the body has obviously adapted to our physical environment, the brain has adapted to a psychological or social environment that has been, we assume, a major shaper of the brain and of how it is structured.’
    This is an allusion to one of the big debates withinthe field of contemporary neurology: to what extent has the brain evolved and developed according to Darwinian theory? The most famous protagonist of Darwinian theory as applied to psychological development (opposed by the science writer Stephen Jay Gould) is Stephen Pinker. In an interview Professor Pinker told me: ‘After having argued that language was some kind of distinct part of the human mind, the natural question was: so what are the other parts?’ The central idea of
How The Mind Works
can be stated in a sentence: ‘The mind,’ says Pinker, ‘is a system of organs of computation, designed by natural selection to solve the kinds of problems our ancestors faced in their foraging way of life, in particular, understanding and outmanoeuvring objects, animals, plants and other people.’ In other words, ‘the mind is what the brain does’. Or, as he says, ‘To put it crudely, the brain is like a computer that evolved.’
    One of the most important recent developments in neurology is the recognition that the brain is rather more plastic (i.e.