Neurology and Law

Imagine this futuristic courtroom scene. The defence barrister stands up, and pointing to his client in the dock, makes this plea: “The case against Mr X must be dismissed. He cannot be held responsible for smashing Mr Y’s face into a pulp. He is not guilty, it was his brain that did it. Blame not Mr X, but his overactive amygdala.”

The legal profession in America is taking an increasing interest in neuroscience. There is a flourishing academic discipline of “neurolaw” and neurolawyers are penetrating the legal system. Vanderbilt University recently opened a $27 million neuroimaging centre and hopes to enrol students in a programme in the law and neuroscience. In the courts, as in the trial of serial rapist and murderer Bobby Joe Long, brain-scan evidence is being invoked in support of pleas of diminished responsibility. The idea is abroad that developments in neuroscience – in particular the observation of activity in the living brain, using techniques such as functional magnetic resonance imaging – have shown us that we are not as free, or as accountable for our actions, as we traditionally thought.

Defence lawyers are licking their lips at the possibility of (to use law professor Jeffrey Rosen’s succinct phrase) placing “the brain on the stand” to take the rap on behalf of the client. Though they failed to cut much ice in Long’s case, arguments that blame lies not with the defendant but with his overactive amygdala (supposedly responsible for aggressive emotions) or his underactive frontal lobes (supposedly responsible for inhibiting the expression of such emotions) are being deployed with increasing frequency. If our brains are in charge, and bad behaviour is due to them, our attitude to criminal responsibility, to punishment (the balance between rehabilitation and retribution) and to preventive detention of individuals thought to have criminal tendencies may all have to change.

Before we invest millions in “neurolaw” centres, however, we need to remind ourselves that observations of brain activity in the laboratory can explain very few things about us. We have no neural explanation for: sensations; the differences between sensations; the way our consciousness coheres at any particular time and over time; our relationship to an explicit past and an explicit future; our sense of being a self; and our awareness of other people as having minds like ourselves. All of these are involved in ordinary, waking behaviour. The confident assertion that “his brain made him do it”, except in well-attested cases – such as the automatisms associated with certain forms of epilepsy or the disinhibited behaviour that may follow severe brain injury – therefore goes beyond our current knowledge or understanding.

Those who blame the brain should be challenged as to why they stop at the brain when they seek the causes of bad behaviour. Since the brain is a physical object, it is wired into nature at large. “My brain made me do it” must mean (ultimately) that “The Big Bang” made me do it. Neuro-determinism quickly slides into determinism tout court.

And there is a contradiction built into the plea of neuromitigation. The claim “my brain made me do it” suggests that I am not my brain; even that my brain is some kind of alien force. One of the founding notions of neurolaw, however, is that the person is the brain. If I were my brain, then “My brain made me do it” would boil down to “I made me do it” and that would hardly get me off the hook. And yet, if I am not identical with my brain, why should a brain make me do anything? Why should this impersonal bit of matter single me out?

The brain is, of course, the final common pathway of all actions. You can’t do much without a brain. Decapitation is, in most instances, associated with a decline in IQ.

Nevertheless, there is a difference between events that owe their origin to the stand-alone brain – for example the twitching associated with an epileptic fit – and actions that do not. While we do not hold someone responsible for an epileptic fit, we do hold them responsible for driving against medical advice and causing a fatal crash. The global excuse “my brain made me do it” would reduce life to a condition of status epilepticus.

In practice, most brain-blamers are not prepared to deny everyone’s responsibility for anything and everything. While the brain is blamed for actions that attract moral disapprobation or legal sanction, people do not normally pass responsibility on to their brains for good actions or for neutral actions such as pouring a cup of tea or just getting up for a stretch after a long sit down. When asked why he is defending a particular client, a barrister is unlikely to say: “My brain made me do it, your honour.” This pick-and-mix neuro-determinism is grounds for treating a plea of “neuro-mitigation” with caution.

So we still retain the distinction between events such as epileptic fits that can be attributed to brain activity and those that we attribute to persons who are more than mere neural activity. Deciding on the boundaries of our responsibility for events in which we are implicated cannot be handed over to neuroscientists examining the activity of the isolated brain in the laboratory. As Stephen Morse, a professor of law, has reminded us, it is people, not brains, who commit crimes and “neuroscience . . . can never identify the mysterious point at which people should be excused responsibility for their actions”. That moral, legal question must be answered not in laboratories but in courtrooms and legislatures.

Meanwhile, the neuromitigation of blame has to be treated with suspicion except in those instances where there is unambiguous evidence of grossly abnormal brain function or abnormal mental function due to clearcut illness that may have its origin in brain disease. Our knowledge of the relationship between brain and consciousness, brain and self, and brain and agency is so weak and so conceptually confused that the appeal to neuroscience in the law courts, the police station or anywhere else is premature and usually inappropriate. And, I would suggest, it will remain both premature and inappropriate. Neurolaw is just another branch of neuromythology.


Why blame me? It was all my brain’s fault
The dubious rise of ‘neurolaw’ Raymond Tallis

The Times Oct 24, 2007

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