Brain Scans of Pain Raise Questions for the Law

PALO ALTO, CALIFORNIA—Ready or not, neuroimaging is knocking on the courthouse door. Last summer, Sean Mackey, a neurologist who directs Stanford University's Pain Management Center, was asked by defense lawyers in a workers' compensation case to serve as an expert witness. A man who received chemical burns in a workplace accident was seeking compensation from his employer, claiming that the accident had left him with chronic pain. The evidence his lawyers assembled included functional magnetic resonance imaging (fMRI) scans of his brain that showed heightened activity in the “pain matrix,” a network of brain regions implicated in dozens of studies on the neural basis of pain.