Posts Tagged ‘thought police’

Not Ready for Prime Time: Brain-Scan Reliability in Question

Tuesday, March 13th, 2012

Almost from our first post, we’ve written here about developments in brain-scan technology and its applicability to criminal law (see here, here, here and here, for example). So needless to say, the past nine days have been of great interest, as the research behind neuroimaging’s claims has come into hot dispute.

Now, just because our motto is “truth, justice and the scientific method,” that doesn’t make us qualified to assess the merits of the underlying science. Our observations on the actual science wouldn’t be worth the pixels. But fortunately, as with most such disputes, the issue isn’t so much the data as the math — the statistical analysis being used to make sense of the data. And we’re somewhat confident that we can at least report on such issues without getting them too wrong.

So briefly what’s going on is this:

First, lots of neuroimaging papers out there, some very influential, see apparent connections between brain activity at point X and mental state A. But what are the odds your reading of X was just a fluke, and the real spot is somewhere else, over at Z? If you do enough tests, you’re going to see X every now and then just by chance. So you have to figure out what the chances are that X would be a random result, instead of the real thing, and apply that correction to your statistical analysis. As it happens, however, for a long time the neuroimaging folks weren’t using an accurate correction. Instead, they were applying a lax rule-of-thumb that didn’t really apply. It’s since been shown that using the lax math can result in apparent connections to variables that didn’t even exist at the time.

On top of all that, as neuroscientist Daniel Bor mentions in his excellent (and much more detailed) discussion here, there’s reason to suspect that (more…)

A Neat Primer on Neuroscience and Criminal Law

Monday, November 7th, 2011


One of our favorite topics here at the Criminal Lawyer has been the interaction of brain science and criminal law. So it’s with a pleased tip of the hat to Mark Bennett that we have the video linked above, an excellent summary of modern neuroscience as it applies to deep policies of our jurisprudence — Culpability, free will, the purposes of punishment, and how (or whether) to punish. The lecture was given about a year and a half ago by David Eagleman, a neuroscientist with a gift for explaining the stuff to non-scientists like us.

Most popularized science is weighed down with histories of how we got here, rather than discussions of where “here” is and where we might be going next. It’s a necessity, but unlike most popularizers Eagleman manages to cover that ground in just the first half of the lecture, rather than the more usual first 80%. So if you want to cut to the chase, you can skip to around the 15-minute mark. We enjoyed watching it all the way through, however. Once he gets going, he neatly and clearly presents ideas that many should find challenging — not because they undermine criminal jurisprudence, but because they challenge much that it merely presumes.

One particularly challenging idea of his is that, as we understand more and more how the brain works, and especially the smaller and smaller role that free will plays in our actions, the less focused on culpability we should be. Rather than focusing on whether or not an individual was responsible for a criminal act, the law should instead care about his future risk to society. If he’s going to be dangerous, then put him in jail to protect us from him, instead of as a retroactive punishment for a crime that may never happen again. The actuarial data are getting strong enough to identify reasonably-accurate predictors of recidivism, so why not focus on removing the likely recidivists and rehabilitating the rest?

Of course, as we mentioned the other day, there’s an inherent injustice when you punish someone for acts they have not yet committed, just because there’s a statistical chance that they might do so at some point in the future. That kind of penalty must be reserved for those who have actually demonstrated themselves to be incorrigible, those who reoffend as soon as they get the chance. Punishment must always be backwards-looking, based on what really happened, and not on what may come to pass.

We have quibbles with some other points he makes, as we always do when people from other disciplines discuss the policy underpinnings of criminal jurisprudence. But on the whole, this is a worthwhile watch, and we’d like to hear what you think of it.

Thought Police?

Monday, October 20th, 2008

brain scan

Guilt or innocence, one might say, is all in the mind. After all, there are very few crimes that can be committed without the requisite mens rea, or mental state. If we’re going to punish someone, their acts cannot have been mere accident. We want to know that they had some knowledge that their actions could cause harm, and we want that awareness to be sufficiently high as to require punishment.

The standard criminal levels of mens rea are “negligence” (you ought to have known bad things could happen), “recklessness” (you had good reason to believe that bad things would probably happen), “knowledge” (bad things were probably going to happen), and “intent” or “purpose” (you wanted bad things to happen). If your foot kicks someone in the ribs while you’re falling downstairs, you’re not a criminal. But if you kick someone in the ribs because you don’t like them, then society probably wants to punish you.

We cannot know what anyone was thinking when they did something, however. So we rely on jurors to use their common sense to figure out what an accused must have been thinking at the time.

In recent years, however, there have been enormous advances in neuroscience. Brain scans, the software that processes the data, and good science have approached levels that would have been considered science fiction as recently as the Clinton years. Experts in the field can see not only how the brain is put together, but also what an individual brain is doing in real time. Experimental data show which parts of the brain are active when people are thinking certain things, with good detail.

Functional magnetic resonance imaging (fMRI), in particular, can act as a super lie-detector. Instead of measuring someone’s perspiration and heart rate while they answer questions during a polygraph exam, fMRI looks at actual real-time brain activity in areas having to do with logic, making decisions, perhaps even lying. Experimental data of large groups is pretty good at identifying what parts of the brain are associated with different kinds of thinking.

Every brain is slightly different, of course. Brain surgeons have to learn the individual brain they’re operating on before they start cutting. So general group data don’t translate to an individual person 100%. So any lie-detector use for fMRI would have to require some baseline analysis before proceeding to the important questions.

The issue is whether it will be admissible in court. Polygraph tests generally aren’t admissible, because they’re more an art than a science. But fMRI is all science. In addition, brain scans are already widely admissible for the purpose of reducing a sentence because the defendant had damage to his brain. As forensic neuroscience expert Daniell Martell told the New York Times in 2007, brain scans are now de rigeur in capital cases. In Roper v. Simmons, the Supreme Court, ruling that adolescents cannot be executed, allowed brain scan evidence for the purpose of showing adolescent brains really are different.

Outside the United States, brain scans have already begun to be used by the prosecution to show guilt. In India, a woman was recently convicted of murdering her ex-boyfriend with the admission of brainwave-based lie detection. There was other evidence of guilt as well, including the fact that she admitted buying the poison that killed him. But the brainwave analysis was admitted.

There are deeper policy issues here. Is reading someone’s brain activity more like taking a blood sample, or more like taking a statement? The Miranda rule is there, at heart, because we do not want the government to override people’s free will, and force them to incriminate themselves out of their own mouths against their will. That’s why the fruits of a custodial interrogation are presumed inadmissible, unless the defendant first knowingly waives his rights against self-incrimination. And because the DNA in your blood isn’t something you make of your own free will, by taking a blood sample against your will the government has not forced you to incriminate yourself against your will.

So is a brain scan more like a blood sample? Is it simply taking evidence of what is there, without you consciously providing testimony against yourself? Or will it require the knowing waiver of your Fifth and Sixth Amendment rights before it can be applied?

We’re interested in your thoughts. Feel free to comment.