Functional MRI lie detection: too good to be true?

Neuroscientists are now applying a 21st-century tool to an age-old question: how can you tell when someone is lying? Relying on recently published research, two start-up companies have proposed to use a sophisticated brain-imaging technique, functional magnetic resonance imaging (fMRI), to detect deception. The new approach promises significantly greater accuracy than the conventional polygraph--at least under carefully controlled laboratory conditions. But would it work in the real world? Despite some significant concerns about validity and reliability, fMRI lie detection may in fact be appropriate for certain applications. This new ability to peer inside someone's head raises significant questions of ethics. Commentators have already begun to weigh in on many of these questions. A wider dialogue within the medical, neuroscientific, and legal communities would be optimal in promoting the responsible use of this technology and preventing abuses.