MRI in the courtroom as witness on pain?

Greg Miller notes, in his report on a Stanford Law School Event, that because pain pathways in the brain are better understood than those underlying lying, pain detection is more likely to be the first fMRI application to find widespread use in the courtroom.

...pain is an issue in about half of all tort cases, which include personal injury cases. Billions of dollars are at stake. Yet people with real pain are sometimes unable to prove it, and malingerers sometimes win cases by faking it...However, using fMRI as a painometer isn't straightforward. For starters, said Katja Wiech, a cognitive neuroscientist at University College London, pain sensitivity varies considerably from one person to the next. It's also influenced by psychological factors such as anxiety (which tends to make pain worse) and attention (focusing on pain makes it worse; distractions take the edge off). Such influences also show up in fMRI scans, Wiech said. Moreover, she and others noted that several studies have found broad overlap in the brain regions activated by real and imagined pain--something that could be exploited by plaintiffs with bogus claims.

A. Vania Apkarian, a neuroscientist at Northwestern University in Evanston, Illinois, was more optimistic. His group has found that activity in the medial prefrontal cortex and the right insula correlates well with pain intensity and the duration of chronic pain, respectively, in people with chronic back pain. "This is an objective measure of pain in these patients," Apkarian said. Based on these and other findings, he predicted that fMRI will be courtroom-ready sooner than others had suggested. "Maybe not in 2008, maybe in 2012," he said. "It's inevitable."

Apkarian's data looked promising to several legal experts in attendance. "You scientists care more about causation than we do in the law," said Stanford law professor Henry "Hank" Greely. "If the correlation is high enough, … we would see that as a useful tool." Indeed, Greely and others noted, even if fMRI can't provide a perfectly objective measure of pain, it may still be better than the alternatives. "We let people get on the stand … and say all kinds of things that may or may not be true," said William Fletcher, a judge on the U.S. Court of Appeals for the Ninth Circuit.