Brain-scanning technology is not ready for prime time in the legal system; it provides less information than people presume. And scientists now know that the brain runs largely on autopilot; it acts first and asks questions later, often explaining behavior after the fact. So if much of behavior is automatic, then how responsible are people for their actions?

These are among the concerns of  neuroscientist Dr. Michael S. Gazzaniga in his new book, Who’s in Charge? Free Will and the Science of the Brain.