Thursday, June 16, 2011

Reasonable Doubts about "The Brain on Trial"

I agree with a lot of what David Eagleman has to say in "The Brain on Trial" in this month's Atlantic, and I find him an interesting and provocative thinker. But I had a few reservations.
First, let me say that I have been reading a lot about him lately, and I read his book about how the internet can save civilization (on the iPad), and it was interesting.
Some of these ideas have been stewing since he gave a talk on the topic of neuro-law here at Randolph-Macon College a few months ago. I had the unique pleasure of getting to talk to him for about 45 minutes in my office. I was a bit star struck at the time, but would have been even more so had I known he was about to be profiled in the New Yorker (by Burkhard Bilger, no less!).

Ok, a quick overview for those of you who don't want to follow any of the links above:
He argues that we should redesign our legal system to reflect how much we know about the brain.
What relevant findings does modern neuroscience tell us? First, the amount of free will we have is on a spectrum. No argument there, we don't hold children as blameworthy as adults, and we make allowances for accidental deaths, or the insanity defense. But second (and this is important) we don't have as much free will as we think we do. A lot of modern psychology and neuroscience show how our unified sense of our conscious thoughts controlling our actions is an illusion. Not only that, but in certain situations we we can look at the brain, and tell how much free will someone has (tumor in the frontal lobe, you lose control of yourself). And we can look at a loss of free will, and predict what we are going to see in the brain (you are losing control of yourself, maybe something is wrong with your frontal lobe).

How should this be applied to the legal system? Eagleman urges to drop assessment of blameworthiness, or intent altogether, and instead look to the future, at reducing recidivism. If we can tell whether someone is likely to commit another crime, that should influence how our legal system deals with them. He argues that we have a lot of good actuarial data on predicting recidivism, and that as neuroscience matures further, we will get even better predictions about who will commit another crime. If we care about the safety of our populace, and the reform of our criminals, why don't we position the legal system to prevent crimes, instead of simply reacting to them?

What's not to like? I agree that our legal system could be better, and more fair, if we took into account recidivism rates, and incorporated crime prevention programs like drug treatment instead of simply punishing and imprisoning. And I agree that we should recognize that dealing with lead paint is a great crime prevention program. But here's where I am skeptical of Eagleman's neuro-optimism:

We don't need neuroscience for any of this.

We can (and should) make our legal system forward-looking because we should recognize that a legal system should not just punish wrong-doing but reduce the circumstances that lead to crime. Exposure to lead paint, drug addiction, and PTSD are all things to be treated, not to be punished.

Social programs and policies should be designed with the knowledge that we have less free will than we think we do. Watson and Skinner said this 75 years ago. Yes, they overreached, and Chomsky and the computer revolution led us away from rats, pigeons and the brain as a black box and towards the mind as an information processor.  Another way of putting this is: the environment is powerful. Eagleman believes his knowledge of brain areas and circuits puts him in a different league than Skinner and the behaviorists, but his argument is not that different. And he is not really any closer to scanning someone's brain and predicting a complex behavior.

As Michael Gazzaniga, an esteemed neuroscientist, mentioned off-hand at his talk at the Association for Psychological Science this year: There are frontal lobe patients who lose control and kill people, but many more who don't. And plenty of serial killers don't have frontal lobe abnormalities. Basically, while we can make a probabilistic judgment that damage to the frontal lobe is more likely to impair your judgment than damage anywhere else, we can't make an individual judgment that one person's actions are due to a particular element of their brain anatomy or chemistry.

Finally, there is one piece of the article that for me represents a lot of what bugs me about his approach (and it  is not uncommon in modern neuroscience). He describes a prefrontal workout, "in which the frontal lobes practice squelching the short-term brain circuits." In what amounts to a super charged, fMRI -sophisticated biofeedback system, you see the pattern of brain activity that corresponds with craving, and then you try to reduce that pattern of brain activity. This just seems odd and incredibly indirect to me. We don't want to reduce brain patterns. We want to reduce cravings. There are some decent ways of reducing cravings, at least for cigarettes. Eagleman ignores effective psychological treatments and therapies, while trumpeting the dubious triumphs of Prozac, thinking that at some point we will understand the brain enough to directly hack its circuitry. We certainly know a lot more about how the biology of the brain relates to behavior than we did 20 or 30 years ago.

But sometimes the best way to change behavior, is to change behavior, and measure behavior.

In the end, I am a big fan of David Eagleman. His energetic mind, his boundless joy and love of science and his optimism are a wonder to behold. For someone with such confidence in his ideas of applying science to solve the problems of society, he was disarmingly modest and patient with all the questions I saw him answer during his short stay in Ashland. I hope he succeeds in his aim of making our legal system more forward thinking, environmental, and less black and white when it comes to free will. But I wish the wide-eyed optimism about what neuroscience can do was tempered with some acknowledgement that neuroscience isn't the last word on the human condition.

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