Brain scans of convicted felons can predict which ones are most likely to get arrested after they get out of prison, scientists have found in a study of 96 male offenders, reports Wired Science today
“It’s the first time brain scans have been used to predict recidivism,” said neuroscientist Kent Kiehl of the Mind Research Network in Albuquerque, New Mexico, who led the new study. Even so, Kiehl and others caution that the method is nowhere near ready to be used in real-life decisions about sentencing or parole.
“Generally speaking, brain scans or other neuromarkers could be useful in the criminal justice system if the benefits in terms of better accuracy outweigh the likely higher costs of the technology compared to conventional pencil-and-paper risk assessments, says Stephen Morse, a legal scholar specializing in criminal law and neuroscience at the University of Pennsylvania. The key questions to ask, Morse says, are: “How much predictive accuracy does the marker add beyond usually less expensive behavioral measures? How subject is it to counter-measures if a subject wishes to ‘defeat’ a scan?”
“Those are still open questions with regard to the new method, which Kiehl and colleagues, including postdoctoral fellow Eyal Aharoni, describe in a paper to be published this week in the Proceedings of the National Academy of Sciences. The test targets impulsivity. In a mobile fMRI scanner the researchers trucked in to two state prisons, they scanned inmates’ brains as they did a simple impulse control task. Inmates were instructed to press a button as quickly as possible whenever they saw the letter X pop up on a screen inside the scanner, but not to press it if they saw the letter K. The task is rigged so that X pops up 84 percent of the time, which predisposes people to hit the button and makes it harder to suppress the impulse to press the button on the rare trials when a K pops up.
“Based on previous studies, the researchers focused on the anterior cingulate cortex, one of several brain regions thought to be important for impulse control. Inmates with relatively low activity in the anterior cingulate made more errors on the task, suggesting a correlation with poor impulse control.”