IN AN attempt to treat depression, neuroscientists once carried out a simple experiment. Using electrodes, they stimulated the brains of women in ways that caused pleasurable feelings. The subjects came to no harm—indeed their symptoms appeared to evaporate, at least temporarily—but they quickly fell in love with their experimenters.

Such a procedure (and there have been worse in the history of neuroscience) poses far more of a threat to human dignity and autonomy than does cloning. Cloning is the subject of fierce debate, with proposals for wholesale bans. Yet when it comes to neuroscience, no government or treaty stops anything. For decades, admittedly, no neuroscientist has been known to repeat the love experiment. A scientist who used a similar technique to create remote-controlled rats seemed not even to have entertained the possibility. “Humans? Who said anything about humans?” he said, in genuine shock, when questioned. “We work on rats.”

Ignoring a possibility does not, however, make it go away. If asked to guess which group of scientists is most likely to be responsible, one day, for overturning the essential nature of humanity, most people might suggest geneticists. In fact neurotechnology poses a greater threat—and also a more immediate one. Moreover, it is a challenge that is largely ignored by regulators and the public, who seem unduly obsessed by gruesome fantasies of genetic dystopias.

A person's genetic make-up certainly has something important to do with his subsequent behaviour. But genes exert their effects through the brain. If you want to predict and control a person's behaviour, the brain is the place to start. Over the course of the next decade, scientists may be able to predict, by examining a scan of a person's brain, not only whether he will tend to mental sickness or health, but also whether he will tend to depression or violence. Neural implants may within a few years be able to increase intelligence or to speed up reflexes. Drug companies are hunting for molecules to assuage brain-related ills, from paralysis to shyness (see article).

A public debate over the ethical limits to such neuroscience is long overdue. It may be hard to shift public attention away from genetics, which has so clearly shown its sinister side in the past. The spectre of eugenics, which reached its culmination in Nazi Germany, haunts both politicians and public. The fear that the ability to monitor and select for desirable characteristics will lead to the subjugation of the undesirable—or the merely unfashionable—is well-founded.

Not so long ago neuroscientists, too, were guilty of victimising the mentally ill and the imprisoned in the name of science. Their sins are now largely forgotten, thanks in part to the intractable controversy over the moral status of embryos. Anti-abortion lobbyists, who find stem-cell research and cloning repugnant, keep the ethics of genetic technology high on the political agenda. But for all its importance, the quarrel over abortion and embryos distorts public discussion of bioethics; it is a wonder that people in the field can discuss anything else.

In fact, they hardly do. America's National Institutes of Health has a hefty budget for studying the ethical, legal and social implications of genetics, but it earmarks nothing for the specific study of the ethics of neuroscience. The National Institute of Mental Health, one of its component bodies, has seen fit to finance a workshop on the ethical implications of “cyber-medicine”, yet it has not done the same to examine the social impact of drugs for “hyperactivity”, which 7% of American six- to eleven-year-olds now take. The Wellcome Trust, Britain's main source of finance for the study of biomedical ethics, has a programme devoted to the ethics of brain research, but the number of projects is dwarfed by its parallel programme devoted to genetics.

Uncontrollable fears

The worriers have not spent these resources idly. Rather, they have produced the first widespread legislative and diplomatic efforts directed at containing scientific advance. The Council of Europe and the United Nations have declared human reproductive cloning a violation of human rights. The Senate is soon to vote on a bill that would send American scientists to prison for making cloned embryonic stem cells.

Yet neuroscientists have been left largely to their own devices, restrained only by standard codes of medical ethics and experimentation. This relative lack of regulation and oversight has produced a curious result. When it comes to the brain, society now regards the distinction between treatment and enhancement as essentially meaningless. Taking a drug such as Prozac when you are not clinically depressed used to be called cosmetic, or non-essential, and was therefore considered an improper use of medical technology. Now it is regarded as just about as cosmetic, and as non-essential, as birth control or orthodontics. American legislators are weighing the so-called parity issue—the argument that mental treatments deserve the same coverage in health-insurance plans as any other sort of drug. Where drugs to change personality traits were once seen as medicinal fripperies, or enhancements, they are now seen as entitlements.

This flexible attitude towards neurotechnology—use it if it might work, demand it if it does—is likely to extend to all sorts of other technologies that affect health and behaviour, both genetic and otherwise. Rather than resisting their advent, people are likely to begin clamouring for those that make themselves and their children healthier and happier.

This might be bad or it might be good. It is a question that public discussion ought to try to settle, perhaps with the help of a regulatory body such as the Human Fertilisation and Embryology Authority, which oversees embryo research in Britain. History teaches that worrying overmuch about technological change rarely stops it. Those who seek to halt genetics in its tracks may soon learn that lesson anew, as rogue scientists perform experiments in defiance of well-intended bans. But, if society is concerned about the pace and ethics of scientific advance, it should at least form a clearer picture of what is worth worrying about, and why.