New brain scan predicts criminal activity before it happensS

Neuroscientists have identified a brain scan that enables them to predict whether convicted felons are likely to land themselves back in jail after they've been released. But have they discovered the "repeat offense area" of the brain? Far from it.

Nature News' Regina Nuzzo summarizes the researchers' findings (emphasis in bold):

Kent Kiehl, a neuroscientist at the non-profit Mind Research Network in Albuquerque, New Mexico, and his collaborators studied a group of 96 male prisoners just before their release. The researchers used functional magnetic resonance imaging (fMRI) to scan the prisoners’ brains during computer tasks in which subjects had to make quick decisions and inhibit impulsive reactions.

The scans focused on activity in a section of the anterior cingulate cortex (ACC), a small region in the front of the brain involved in motor control and executive functioning. The researchers then followed the ex-convicts for four years to see how they fared.

Among the subjects of the study, men who had lower ACC activity during the quick-decision tasks were more likely to be arrested again after getting out of prison, even after the researchers accounted for other risk factors such as age, drug and alcohol abuse and psychopathic traits. Men who were in the lower half of the ACC activity ranking had a 2.6-fold higher rate of rearrest for all crimes and a 4.3-fold higher rate for nonviolent crimes.

The study, which was published yesterday in Proceedings of the National Academy of Sciences, is the latest in a recent string to investigate how brain imaging scans might be used to forecast future behavior. But the technical issues with this and other predictions that rely on neuroimaging are manifold.

For one thing, the imaging technique relies on fMRI, the reliability of which remains a hotly debated issue. This particular breed of brain scan was recently shown to pick up activity in the brains of dead fish – an embarrassing PR hangup that should keep this technique far from any parole hearings for the foreseeable future.

Its other major shortcoming is obvious: the scan is not perfect. Someone with low ACC activity is not guaranteed to commit a crime that lands him back in prison. This eliminates the possibility of the scan being employed in a Minority Report scenario, used to determine which prisoners are released and which are kept behind bars. At the same time, it raises significant ethical issues about the technique's use in dictating a prisoner's sentence (a prisoner flagged as being at high risk of reoffense might, for instance, be administered stricter parole terms).

In these ways, the newly identified scan will surely face similar criticisms as the the oft-maligned lie-detecting polygraph (even if Kiehl, himself, believes it "isn't ready for prime time" – indeed, it may never be suited for as high-stakes an environment as prison). But there's an importance difference between the two, namely the fledgling nature of brain science and its potential to reveal important insights into human behavior and society at large.

The researchers' findings are published in the latest issue of PNAS. For more details, visit Nature News.

Top image via this coincidentally appropriate legal article on whether fMRI lie detection evidence is admissible in court.