Fighting Off Prozac Nation

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Viren Swami appreciates good neuroscience.

Faced with escalating violence in US cities during the 1960s, neuroscientists Vernon Mark and Frank Ervin, in research funded by US law enforcement agencies, argued that riots may have been precipitated by individuals with damaged or overactive emotional centres in the brain. A potential treatment would be to remove those brain centres in selected 'ghetto ringleaders' whose infractions included problems of 'respect towards officials', 'militancy' and reading an 'avalanche of revolutionary material'. Together with the rise of new drugs and other psychological conditioning techniques, many like Mark and Ervin hailed the coming of a technologically 'psychocivilised society'.

It failed to happen then, but could it now? Today neuroscientific research has been stepped up to unprecedented levels. New tools, from molecular genetics to the windows into the brain offered by imaging techniques, have transformed our understanding of what is the most complex structure in the known universe. Markets for drugs such as Prozac and Ritalin are earning their makers nearly $50 billion annually. And yet, says Rose, himself a leading figure in the neuroscientific revolution (working specifically on memory), much of this research is driven by embarrassingly crude models of the brain.

At the heart of Rose's concern is the seemingly endless battle being fought between philosophers, sociologists and psychologists over neuroscientific descriptions of human nature. The brain is commonly treated as some kind of information processing system - a machine that can be explained and manipulated once we have a blueprint of its circuits. Among the 'bad hats' of neuroscience peddling such reductionist approaches, he cites the Nobel Prize winner Francis Crick, who claimed that we are 'nothing but a bunch of neurons', and evolutionary psychologists like Steven Pinker who reduce human behaviour to genetic programmes.

In the Meno Plato begins the dialogue by asking Socrates if 'virtue can be taught, or is it rather to be acquired by practice? Or is it neither to be practised nor learned, but something that comes to men by nature or in some other way?' Plato is asking about the causes of human behaviour, and casting it within the archetypal form of the nature-nurture question. Yet, as Rose explains, the dichotomy between nature (genes, brain chemistry) and nurture (environment) is a false division that would best be killed off in what Susan Oyama once described memorably as 'the stake in the heart move', the heart being the notion that some influences are more equal than others.

For Rose and other 'developmental systems theorists' like Oyama, the brain is holistic, a living system which is always undergoing development. Activity at one phase alters the conditions that become the basis for the next stage. In addition, there is a global cohesion that reaches down to organise the parts even while those parts may be adding up to produce the functioning whole. Rose cites his own research on the neurochemistry of depressed patients.

A reductionist view of brain function sees depression as being caused by a chemical imbalance at nerve junctions, which can be treated with chemicals like Prozac. But experiments by Rose showed that psychotherapy could also restore the neurochemical balance to normal, and - more troublesome for reductionist thinking - people working under stress had the same neurochemical profile as the depressed despite feeling perfectly cheerful. Thus there is no simple chain of cause and effect linking events at the cellular and psychological levels.

This complexity moves Rose to dismiss much of the current enthusiasm for mood controllers, memory boosters and other such forms of 'mental Viagra'. Repeatedly he calls it selling snake oil - we simply do not understand the brain well enough to mend it in reliable ways, let alone enhance its performance. But Rose also goes beyond the well established promise of pharmaceuticals to look at some of the new technologies of the mind like gene-based therapies and biocybernetics. How will these be used? What are the ethical and bio-social implications? Will they be used for good or ill?

To be sure, this should have been an angrier book. As a long-time critic of reductionist science coming to the end of his career, Rose could have, as the neuroscientist John McCrone put it, 'given his peers both barrels'. Despite the subdued tone, however, Rose makes it clear that the past is the key to the future. Understanding the human brain requires that we explore the evolutionary route by which brains emerged, but also how brains develop from a single fertilised egg to the hundred billion nerve cells that each human possesses. And in asking what the future holds for the human brain, The 21st Century Brain is a most powerful weapon in the fight against reductionist science.

The 21st Century Brain
Steven Rose
Jonathan Cape £20