Noises from the Darkroom: The Science and Mystery of the Mind. Guy Claxton

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      Neural Webs

      The brain is a focus for the co-ordinating aspect of the body, just as the intestines are the main centre for digestion, or the legs of locomotion. But if you want to understand digestion or locomotion fully, you will have to take a systems view, and understand the role of the jaws, and of exercise, in digestion; or of the lungs and the spine in mobility. Just so, the brain plays a central part in integrating processes but the processes are themselves essentially bodily. ‘Mind’ is an aspect of an animal that is distributed throughout the body even though some facets of ‘mind’ are most closely associated with the nervous system. The unit of intelligence of an animal is its body, not its brain, just as the unit of ‘music-making’ is the orchestra, not the conductor. If the orchestra is big, and the music intricate, the conductor’s role is all the more important. But he never transcends his role as a valued member and servant of the musical collective. He never becomes a dictator.²⁰

      For example the immune system is usually discussed in relative isolation from the CNS. However, some interesting recent research has revealed how ‘brain-like’ the immune system actually is, and has explored the ways in which CNS and immune system continually talk to each other. A class of messenger molecules from the peptide family has been shown by Candace Pert and others to mediate between the neural and immune systems, and thereby to co-ordinate, and effectively integrate, them. She goes so far as to say that: ‘White blood cells are bits of brain floating around the body.’²¹ Francisco Varela has referred to the immune system in a recent paper as ‘the second brain’, and has argued that the secret handshakes that enable the antibodies to recognize ‘friend’ from ‘foe’ also act as the basis for the body’s overall sense of identity. The immune system, like the CNS, is primarily a communication system, he argues; one which subserves the vital bodily feeling of ‘family’.²²

      By taking an evolutionary perspective, we are forcibly reminded of the extent to which intelligence is a bodily, not purely (or even mainly) a mental, phenomenon. And just as most of the workings of the body are ‘dark’ to us, beyond the reach of conscious introspection, so we may begin to open up the question of how much of what we have thought of as our ‘intelligence’, our ‘cognition’, is also inaccessible to the conscious mind. Perhaps intelligence does not reside in consciousness. Perhaps consciousness no more shows us the workings of the mind than a television picture shows us the workings of the television.

      Plastic Brains

      No amount of genetic adaptation can prepare you for the unpredictable. The world is always liable to change in unprecedented ways, and the animal that is not completely pre-set, but which comes with the facility to tune itself to new environmental frequencies as they come on air, has a head start over one that was built on the assumption that its world would last for ever. The ability of an individual to learn a new pattern, and a new trick to cope with it, is, one of the most amazing discoveries of evolution, but it needs, if it is to work, adequate resourcing.

      This is the second good reason for having a brain. A nervous system intricate enough to co-ordinate a wide range of pressures and resources makes a good basis for the next great evolutionary jump: incorporating a degree of flexibility into these interconnections, so that the way they are wired up can (within limits) respond to the success of the system in promoting the individual’s (and her children’s) survival. If it is useful to be born knowing what to do when you see a snake, it is even more useful to be able to record the kinds of situations in which you personally have met snakes before, and to be able recognize a fresh trail, and the distinctive way the grass moves. From the point of view of this book, the brain will be the most interesting of the body’s intelligent subsystems precisely because it is the one that is tuned so comprehensively by experience—and therefore by culture. Muscles and antibodies too are affected by what happens to them, but to nothing like the same extraordinary extent.

      The Brain’s Priorities

      The brain is the centre where information gathered by the rest of the nervous system, about the state of things both inside and outside the body, is collated and integrated. It is the ‘General Communications Head-Quarters’ of the body. Information continually arrives along all the neural pathways, coded as patterns of electrical impulses. The eyes, ears, tongue and nose bring news of what is happening offshore. Internal monitoring stations tell of the level of blood sugar, the fullness of the bladder, the oxygen/carbon dioxide balance in the lungs, the acidity of the gastric juices…and a hundred other indices of the well-being, or the imminence of required action, in different parts of town. The lookouts have just sighted something – is it the long-awaited supply of fresh meat, or is it that marauding pirate? The miller has more corn to grind than he can cope with: is the store-house full or not? The garbage disposal operatives say it is time to take a dump. The power-station workers are complaining because they have missed their tea-break…All these different ‘interests’ make claims on the attention and orientation of the community as a whole. Cases must be heard, priorities decided, less urgent needs postponed, plans of action prepared.

      For example, receptors in the skin, the joints and the muscles tell of aches and pains, pricks and tickles, and update the story about where the limbs are, so that when you need to move, perhaps in an emergency, you already have information about where ‘here’ is, and can therefore compute the arm movement required to get from ‘here’ to ‘there’. A baby reaching for a toy makes a ‘ballistic swipe’: it throws out the hand like a harpoon fired from a ship. If the toy is moved after the movement is started, there is nothing she can do to correct the movement in mid-air. But an older child, whose monitoring of body states and dynamics is more developed, can change the direction of reach immediately. Her hand is now not a simple projectile but a toy-seeking missile, locked on to the target in a much more subtle and responsive fashion. She has learnt how to link the sight of the toy, the sight of her arm, the feel of the arm as it is moving, and the muscular commands that control the arm movement, in a flexible way.

      

      In this chapter I have explained the evolutionary value of plastic brains, and illustrated some of the different jobs that they may be called upon to do. And we have seen how the design function of a brain gets more complicated as the sophistication and differentiation of its body increases. We have developed an overview of what the brain does. But in order to understand it in more detail, we need also to be able to talk about what it is: what it is like, and how it does what it needs to do in order to fulfil its role. This is the subject of the next chapter.

       FOUR The Self-Organizing Organizer

      The cardinal background principle for the theorist is that there are no homunculi. There is no little person in the brain who ‘sees’ an inner television screen, ‘hears’ an inner voice, ‘reads’ the topographical maps, weighs reasons, decides actions and so forth. There are just neurons and their connections. When a person sees, it is because neurons, individually blind and individually stupid neurons, are collectively orchestrated in the appropriate manner…In a relaxed mood we still understand perceiving, thinking, control and so forth, on the model of a self – a clever self – that does the perceiving, thinking and controlling. It takes effort to remember that the cleverness of the brain is explained not by the cleverness of a self but by the functioning of the neuronal machine that is the brain…In one’s own case, of course, it seems quite shocking that one’s cleverness should be the outcome of well-orchestrated stupidity.

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