In the 1956 sci-fi adventure "Forbidden Planet," an American astronaut receives a "brain boost" from an alien machine that temporarily gives him enhanced mental powers. Before he dies from the effects of the boost, he helps unravel the mystery of how the civilization became extinct: It couldn't control its own immense mental powers.
More recently, the characters in "The Matrix" film series are shown "downloading" knowledge into their brains nearly instantaneously. In "Eternal Sunshine of the Spotless Mind" the lead character has the uncomfortable memories of a love affair removed from his mind, with unexpected results.
What used to be confined to speculative fiction is fast becoming scientific fact. Brain boosting, or "neural enhancement," is already being done - and much more powerful techniques are on the way. Some observers say we're rushing into this brain-gain revolution without sufficient thought or preparation.
"We're about to be handed a bunch of powerful new capabilities ... to refashion ourselves, improve ourselves," notes Martha Farah, a director of the Center for Cognitive Neuroscience at the University of Pennsylvania, in an e-mail. "We should always think through the ethical consequences of changing ourselves and our lives, for the individual and for society."
While some may worry that we'll turn ourselves into a race of Frankensteins, others look forward to new Einsteins. Optimists argue that humans are only doing what they've always been doing: trying to improve themselves, whether it's taking caffeine to stay alert or undergoing cosmetic surgery to change their appearance.
The brain-enhancement revolution is already under way. The drug Ritalin, first given to control hyperactivity in children, now is routinely used by healthy high school and college students to sharpen their thinking before taking exams. The long-term health effects are unknown.
Modafinil was developed to treat narcolepsy, a rare condition causing daytime sleepiness. But now it is used by those who simply want to be wakeful and alert, and recently seven American track and field athletes admitted to using it to boost their mental preparation. Transcranial magnetic stimulation, used for nearly two decades to treat depression, has also been found to enhance problem-solving abilities in normal individuals.
Improved brain imaging, or mapping, is yielding new techniques such as "brain fingerprinting," which purports to be able to locate memories within the brain, raising troubling possibilities for invasion of privacy. "There's nothing more private and personal than a person's memories," says Richard Glen Boire, codirector of the Center for Cognitive Liberty and Ethics in Davis, Calif.
Some scientists see a new field emerging they call "neuroethics," which would try to identify where the ethical land mines are buried and how to deal with them. These judgment calls will be vital because the revolution in the neurosciences "is just as important as the genetic revolution, but no one is paying attention," says Arthur Caplan, director of the Center for Bioethics at the University of Pennsylvania.
As in the case of Ritalin, most of the current techniques for enhancing mental abilities come from efforts to treat diseases. In the 2002 book "Our Posthuman Future: Consequences of the Biotechnology Revolution," influential thinker Francis Fukuyama called for governmental regulation of using such technologies for neural enhancement.
But even others with ethical concerns say drawing such a "bright line" between the use of a drug or other technology for therapy or for enhancement is problematic.
Pharmaceutical companies are going to want to produce and market drugs that appeal to 100 percent of the population, not just the minority who are sick at any given time, Mr. Boire points out. After all, many people would like a better memory, to be able to think a little more quickly, or to forget troubling memories.
Yet a number of issues of personal liberty are being raised, he says. "What rights does the person have to manage their own thought processes?" Boire asks. "Thought is not just something that is changed by reading a book or hearing a speaker. Now, and more and more, as time goes on, thought will be changed by pharmacological agents."
How will we be able to say yes to therapy but no to enhancement? Professor Caplan asks. He balks at the idea of telling someone "you can take a pill if you have dyslexia, but you can't take a pill if you're just a poor reader. It's very tough. It won't work."
Others see no need for making an ethical distinction between therapy and enhancement. "There's better and worse. More life is good. More smarts is good," says James Hughes, who teaches health policy at Trinity College in Hartford, Conn., and is author of the forthcoming book "Citizen Cyborg: Why Democratic Societies Must Respond to the Redesigned Human of the Future."
"Sometimes I think I'm arguing for the plow" - a simple dramatic upgrade in human technology, Professor Hughes says. In 100 years, he predicts, "we'll have currently unimaginable cognitive abilities on tap" through technology.
Those who caution about a rush toward neural enhancement - such as Professor Fukuyama; Bill McKibben, author of "Enough: Staying Human in an Engineered Age"; and Leon Kass, the head of the President's Council on Bioethics - are, in Hughes's assessment, "bio-Luddites," dragging their heels against inevitable technological progress.
But in a recent National Science Foundation-sponsored report entitled "Neurocognitive enhancement: What can we do and what should we do?," a group of scientists, educators, and ethicists concluded that "continuing our current laissez- faire approach [toward brain boosting] risks running afoul of public opinion, drug laws, and physicians' codes of ethics. The question is therefore not whether we need policies governing neurocognitive enhancement, but rather what kind of policies we need."
The report identifies a number of areas of concern, including safety, fairness and equity, coercion, and "personhood and intangible values" - and concentrates on the questions surrounding enhancement drugs, stressing that they are leading the way in the field of neuroscience.
Safety considerations should include "both the conventional medical effects and the more subtle psychological effects that are likely to accompany neurocognitive enhancement," says Dr. Farah, an author of the study. "For example, will attentional enhancement become routine and will we use it to become an even more workaholic society than we are now?"
While patients might be willing to undertake some risk to use a drug to treat a disease, enhancement drugs should meet a higher threshold for safety, says Judy Illes, a senior research scholar in biomedical ethics at Stanford University and the study's other author.
Might Ritalin use, for example, cause a loss of mental capacity in old age? Our worry about possible hidden costs to brain boosting is part "of our mistrust of unearned rewards," the sense that we may be making a Faustian bargain, the study says.
Even enhancement advocate Hughes agrees that safety remains important. The Food and Drug Administration needs to certify drug safety "and it needs to be independent of the biomedical industry in a way that it hasn't been," he says.
Mapping the brain brings its own set of concerns, Caplan adds. He foresees brain scans someday being used at airports to screen passengers. Do you have to give informed consent to have someone look at your brain? he asks. What if it can be done at a distance without your knowledge? And who's going to be allowed to keep information about your brain?
Some kind of regulation will be needed. "You don't want people just setting up machines on the sidewalk saying 'I'll tell you if your spouse is cheating on you,'" Caplan says.
Perhaps most troubling - and most difficult to deal with from a scientific basis - is the question of personhood. "Some people just think messing with the brain is unnatural because the brain is the seat of who we are," Caplan says. "To change it is to change our identity."
"It's at the heart of what this new field of neuroethics is all about," Dr. Illes says. That doesn't mean we must forestall research "because it's getting too close to our personhood," she says, "but rather to empower research with critical ethical thinking."
The concept of a "self" does not make much sense in the framework of neuroscience, "where you and I are just big networks of neurons that can be changed by a drug or other procedure," Farah adds. On the other hand, she says, "I feel I have a self, I feel that other brains are persons, and even though this may be an illusion, it is part of my understanding of life that I am not ready to dispense with, no matter what neuroscience tells me!
"I think the most challenging ethical issues in neuroscience have to do with reconciling these two views of human life."