Research support for this article was provided by the Investigative Fund of The Nation Institute.

I. Mapping Brains

Tools for peering inside the human body are not new--and nor are trepidations about them. When X-rays were discovered, doomsayers invoked Faust and Frankenstein, pundits fretted about privacy and entrepreneurial types began hawking X-ray-proof underwear. In retrospect those reactions seem unwarranted, but sometimes technologies that change how we see ourselves do have profound repercussions. Sonograms, for instance, fundamentally altered the abortion debate by changing our understanding of fetal development. Likewise, new technologies for mapping the brain will invite new interpretations of human intellect, agency and behavior.

These technologies, which include positron emission tomography (PET scans) and functional magnetic resonance imaging (fMRI), work by identifying the brain areas involved in performing a given task--recognizing faces, making decisions, recalling memories. Scientists are currently using these tools to search for the neurological underpinnings of virtually the entire sweep of human experience: the propensity for violence; the capacity for cooperation; conscious or unconscious racial attitudes and sexual preferences; religious feeling; truth-telling versus lying; real memories versus false ones; and personality traits such as extroversion, pessimism, risk aversion and empathy.

"It sounds like science fiction. You know, high-tech phrenology--we're going to scan your head and see what kind of person you are," acknowledges Martha Farah, director of the University of Pennsylvania's Center for Cognitive Neuroscience. In the 1970s imaging basically was science fiction; the best technology merely confirmed known facts about the brain. By the 1980s, though, scientists were isolating parts of the brain involved in complex cognition and, a decade later, moods and emotions. Recently, imaging made another crucial leap--from providing information about the average brain to providing information about a specific brain. That is, it began to reveal differences in how individual people think and feel. "We still can't stick someone in a scanner and say, 'This person has an intelligence score of such-and-such,'" Farah says. "But increase the predictive power by a factor of two, and I think you'll get applications beyond the laboratory."

Actually, at least one such application already exists, although it relies on an older technology, electroencephalograms. "Brain fingerprinting," a technique patented by neuroscientist-cum-entrepreneur Lawrence Farwell, determines whether a subject recognizes information by tracking electric waves called P300s, which the brain emits in response to familiar stimuli. In 2000 Farwell conducted a brain fingerprinting test on Terry Harrington, who was serving a life sentence for murder in Iowa, and found that Harrington did not recognize details the killer would have known. The trial court, and later the Iowa Supreme Court, admitted the evidence. (Harrington was ultimately acquitted on different grounds.) Farwell is now marketing brain fingerprinting for medical applications, corporate security, advertising, criminal justice and counterterrorism.

Technologies that glean information directly from our brains give some people the willies, but in essence brain fingerprinting is simply a fancy lie detector--or, in the case of advertising applications, a fancy focus group. The equipment may be new, but the ethical issues it raises are old hat: concerns about accuracy, privacy and the right of suspects to demand testing. These issues are urgent, but our society has both precedents and means for handling them.

However, neuro-imaging does raise a novel ethical issue for our justice system--one that is subtler but potentially farther-reaching than the specter of mind reading. Criminal law is inherently interested in mental states, and specifically in the mens rea, the guilty mind. If I am charged with a crime, the court doesn't merely consider whether I committed the act; it also attempts to establish whether I did so of my own free will. If I acted in self-defense or under extreme coercion, I am deemed innocent. Likewise, if I am judged not wholly competent (e.g., because of mental impairment, childhood abuse or alcohol addiction), I will generally be treated with greater leniency. These mitigating factors are understood as a kind of internal coercion--not the proverbial gun to the head but rather a gun in the head: a brain state that I cannot control and that, on the contrary, controls me. In determining my guilt or innocence, then, the court must decide when I am in control of my actions--that is, when my brain stops running the show and my nonbrain essence, my "me," takes over. But neuroscience brooks no distinction between me and the physical processes of my brain. It therefore rejects the notion of a freely willed act, because I have no "will" above and beyond the neurochemical reactions that make me tick.

This is hardly a new contention--philosophers have been playing free-will tug-of-war for ages--but courts that are indifferent to Spinoza tend to listen to science. "Arguments are nice, but physical demonstrations are far more compelling," write Princeton psychologists Joshua Greene and Jonathan Cohen in the journal Philosophical Transactions of the Royal Society of London. It's one thing to tell a jury that the accused had a troubled childhood, or even to note that early abuse imperils development. It's another thing to explain the exact mechanism that renders a specific person incapable of judgment, empathy or impulse control.

In locating criminality in our brain chemistry--rather than in a corrupted soul or a malignant heart--neuroscience could help forge a less punitive justice system. But that is hardly a foregone conclusion. "It could make people think [criminals] deserve help--the trend we've seen with alcoholism," says Eric Parens, senior research scholar at the Hastings Center, a bioethics institute in New York. But, he cautions, "it could just as easily be interpreted to suggest that they are bad to the bone and should be locked away forever."

The former outcome is presumably preferable to progressives, but it raises its own troubling question: If bad brains cause bad acts, does the law have the right to try to make bad brains better? Imagine, for a moment, the Phineas Gage experiment in reverse: altering the brain to transform a cantankerous lech into a responsible citizen. If we had the power to effect that transformation, would we also have the right?

• « Previous
• 1
• 2
• 3
• 4
• Next »

• Get The Nation at home (and online!) for 75 cents a week!
• If you like this article, consider making a donation to The Nation.