Neuroscience will help us read minds better. We all read minds constantly, but we aren’t very good at it. The subjective feeling of pain depends on the brain; hundreds of thousands of legal claims each year turn on whether a person is feeling pain and, if so, how much. When neuroscience can “see” that pain, the law will change, both in individual cases and in some broad policies. Similarly, if we can ever use neuroscience to help determine whether someone is lying—a use for which substantial controlled experimental evidence already exists—how would we use such a lie detector? At least three courts have already rejected fMRI-based lie detection evidence (properly, I think), but I make no bets about the situation in 2022.
As to responsibility, neuroscience will not turn all criminal law into psychiatry, but there will be cases in which neuroscientific evidence plays a role in deciding whether someone is competent to be tried or to represent himself, really is experiencing aural or visual hallucinations, or, in a few cases, really does seem to deserve a particular verdict or punishment. The case of the child molester whose pedophile impulses were triggered by a tumor is a nice example. One may question whether he should be found guilty of child molestation or, at least, sentenced to prison rather than to surgery. On the other hand, almost no child molesters will be able (credibly) to show a similarly powerful tumor. Neuroscience’s effects on responsibility will mainly be retail, not wholesale.
Surgery raises the issue of “treatment.” No scare quotes are needed when willing patients seek treatment for schizophrenia, Alzheimer’s disease, Parkinson’s disease, or obsessive-compulsive disorders. But what about the unwilling? Should a judge be able to order a defendant to get brain surgery, even if it is proven safe and effective at preventing his future crimes? Or, perhaps, not “order” surgery but give the defendant a “free choice”—life in prison or the knife? Of course, prison also changes your brain—everything, even this article, changes your brain. We know prison is neither safe nor effective. Is it morally different from surgery?
Finally, what about enhancement? We are spending billions of dollars to find treatments to improve the memories of people who have dementia or, perhaps, just age-appropriate memory impairment (afflicting those of us whose memories aren’t as good as we remember our memories having been). What if it works—and what if it works for young people, premeds studying for an organic chemistry exam or law grads cramming for the bar? Is that like using performance-enhancing drugs in sports? Or not? Inevitably, the law must at least draw the borders of the broad social uses of brain-enhancing technologies, as well as decide how it will use those technologies in its own workings.
I have written far more questions than answers because we are just beginning to define the questions, let alone crafting the answers. I am confident that neuroscience, fueled by biomedical research funding and impelled by the moral desire to relieve human suffering, will learn things about the workings of our brains that will spill over from medicine to society, and to law. I am not confident, but I am hopeful, that thinking about some of those dual uses ahead of time will help us manage them wisely—or, at least, less catastrophically. The time to begin—with a proper sense of both timing and proportion—is now.