Forget crack - in the Decade of the Mind, legal 'smart drugs' are de rigueur. Steven Rose urges debate on the future of neuroscience

We are halfway through what has, somewhat hubristically, been termed The Decade of the Mind, and the optimism of some of my neuroscientific colleagues knows few bounds. "Better Brains" shouted the front cover of a special edition of Scientific American a little earlier in the decade, and the titles of the articles inside formed a dream prospectus for the future:

"Ultimate self-improvement"; "New hope for brain repair"; "The quest for a smart pill"; "Mind-reading machines"; "Brain stimulators"; "Genes of the psyche"; and "Taming stress". These, it seems, are the promises offered by the new brain sciences, bidding strongly to overtake genetics as the Next Big Scientific Thing. The phrases trip lightly off the tongue, or shout to us from lurid book covers. There is to be a "post-human future" in which "tomorrow's people" will be "neurochemical selves".

But just what is being sold here? How might these promissory notes be cashed? Is a golden neurocentric age of human happiness "beyond therapy" (as the US President's Commission on Bioethics has termed it) about to dawn? So many past scientific promises - from clean nuclear power to genetic engineering - have turned out to be so perilously close to snake oil that one is entitled to be just a little sceptical. And if these slogans do become practical technologies, what then? What becomes of our self-conception as humans with agency, with the freedom to shape our own lives? And what new powers might accrue to the state, to the military, to the pharmaceutical industry, to yet further intervene in and control our lives?

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As a neuroscientist, I study how the brain works in terms of the properties of its molecules, cells and systems because I believe that this will also help us understand something about how minds work. This, to me, is one of the most interesting and important questions that a scientist - or indeed any other searcher after truth - can ask. The power and range of the new techniques being brought to bear on these questions, ranging from genetic manipulation to functional magnetic resonance imaging, is extraordinary. We know hugely more about the brain and its workings at every level of analysis than in any previous decade. When, more than 40 years ago, I suggested that I might use biochemistry to study how brains make memory, I had to fight the sceptics. Today, memory is one of the hottest topics of molecular neuroscience, and many of my colleagues seem to believe they are on the verge of discovering the brain processes of consciousness. Today I am the sceptic, not convinced that this new knowledge yet adds up to a theory of mind. But what we discover provides more than mere passive knowledge of the world. Increasingly, as the Scientific American headlines suggest, this knowledge offers the prospect of sophisticated technologies for predicting, changing and controlling minds.

Of course, much of this knowledge may be beneficial. In the ageing populations of the West, neurodegenerative diseases, such as Alzheimer's, which involve a seemingly irreversible loss of brain cells and mental function, are an increasing burden. There are likely to be 1 million or so Alzheimer's disease sufferers in the UK by 2020. Neurodegenerative diseases are of complex causation; there are genetic and environmental risk factors and, until recently, attempts to alleviate the disease have focused on drugs to mitigate its effects. But suppose its onset could be predicted more accurately: could one envisage a lifetime on anti-Alzheimer drugs just as today people take statins and anti-hypertensives?

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One thing is sure: we are moving towards a world in which our lives are being modulated by pharmacology in an increasingly medicalised culture, towards what one neuroscientist has called a "psychocivilised society". Throughout recorded history we humans have played with adjusting our minds through drugs (alcohol, cannabis, opium). Aldous Huxley's Brave New World offered a universal panacea, Soma (along with sex of course: "Hug me till you drug me honey; love's as good as Soma"). But the new generations of synthetic drugs, and those currently being researched, offer far more.

Forget the crudity of the illegals, the Ecstasy and the crack. Specific serotonin-receptor inhibitors, such as Prozac, promise to make you "better than well". Smart drugs - cognitive enhancers such as the ones I work on in my own lab for treating Alzheimer's disease - will improve memory and exam performance. Others will enhance attention and reduce the need for sleep, such as the modafinil that US pilots were apparently fed during the Iraq War (don't worry about becoming addicted; there are research programmes under way to create vaccines against that prospect).

But don't step out of line in this psychocivilised society, for if you do, you are clearly sick. Cheek your teachers and disrespect your parents and you are suffering from attention deficit hyperactivity disorder (it used to be called being naughty). Protest against the way the world is, and it might be oppositional defiance disorder; turn your protest into action and it is conduct disorder. Are you over 50? Then you are likely to suffer from age associated cognitive impairment. Check out the Diagnostic and Statistical Manual - the psychiatrists' bible - to see how you and yours fit these categories.

Actually, you won't even have to manifest these undesirable activities. There are supposed genetic predispositions for antisocial behaviour, drug abuse, violence, abnormal sexual preferences, even "tendency to mid-life divorce". So maybe there could be early diagnosis. When the US cancer researcher Dean Hamer reported that he had (he claimed) discovered a gene marker predisposing the men who carried it to be gay, he suggested that he might patent his finding to avoid it being used for prenatal testing. And in the mid-Nineties there came reports that a variant of the gene coding for the enzyme monoamine oxidase A, which degrades neurotransmitters, was associated with violent, aggressive behaviour. A defendant in a US court case, found guilty of murder, called for a genetic test to check if he carried the variant, and hence could plead diminished responsibility.

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Better controlled, more recent studies in New Zealand have shown that the MAOA gene is rather weakly associated with aggressive behaviour in adults, and only if they had been subject to childhood abuse. These claims, and the pressures for gene testing, will only increase as data from the Human Genome Project and its aftermath accumulate. ADHD is said to be associated with changes in another neurotransmitter, dopamine, and both genetic and brain-imaging tests are potentially available offering to predict future outcomes, even if they turn out to become self-fulfilling prophecies. And what can be identified can be prevented, or at least modulated. The paradigm pharmacological case is Ritalin, an amphetamine-like drug prescribed to youngsters diagnosed with ADHD. This disorder, which scarcely existed in Britain 15 years ago, is now reaching epidemic proportions, and Ritalin prescriptions (about 2,000 a year in the early Nineties) are running into the hundreds of thousands.

Let me be clear. I regard many of these proposed mind manipulations as on the fringe of science fiction and their advocates as often little better than snake-oil salespeople with share prices to boost. (If you think I exaggerate, read Forbes magazine's accounts of the new smart-drug entrepreneurs under the headline "Viagra for the brain" or the Financial Times account of the marketing strategy of the pharma company Shire, trying to break into the ADHD drug market in the US). But the fact that a technology may not work does not mean that it will not be developed - think of the US Star Wars project, or former ÁñÁ«ÊÓƵ Secretary David Blunkett's enthusiasm for recording "biodata" on identity cards.

Meantime, there are deeper philosophical questions to consider. In this neurocentric world, what happens to our sense of personal agency, of responsibility? If we are, as Francis Crick once put it, "nothing but a bunch of neurons", and if, as the neurophilosopher Patricia Churchland has argued, it is time to dismiss ill-defined terms such as "mind" as mere "folk psychology", what remains? Is neuroscience about to join with Richard Dawkins in defining us as mere "lumbering robots" programmed through our "on-board computers"? The answer to all these questions, in my understanding of neuroscience, is "no". Without question, our highly developed, immensely plastic brains and minds are the product of 3 billion years of evolution. Evolution has enabled each of us to create our unique selves in the interplay of genes and environment during development, a process called autopoiesis. "The environment" in this sense is the social context, rich in history and technology; the culture in which we are embedded. And it is this that informs our selves and empowers them with agency, not in contradiction to our biological natures, but precisely because of them.

It is because we have such agency that we are able to contemplate and hence, partially, to direct the future. We need to ask how far should - or can - civil society control and regulate these burgeoning neurotechnologies? The time is right to begin thinking about what has become known in the trade as "Elsi" - the ethical, legal and social implications - of such prospects sooner rather than later. Most of the attempts to legislate on issues involving the new genetics have been post hoc. The horse has left the stable before the door has been bolted. But with the neurotechnologies we are still at the stage of predicting futures and there is - just about - time for wider debate about the directions they should take. Indeed, a Europe-wide citizens' consultation on these questions, under the auspices of the European Union, is just beginning.

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Even given our constant and necessary preoccupation with other future hazards, from pandemic flu to climate change, it demands the widest possible attention.

Steven Rose is professor of biology and director of the Brain and Behaviour Research Group at the Open University. His book The 21st Century Brain: Explaining, Mending and Manipulating the Mind is published by Jonathan Cape next week, ?20.00.

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