Friday, May 14th, 2010

MRIs and the Law

fMRI scanner photo by Flora Lichtman

What if the police could scan a suspect’s brain to see if he was lying? Some companies claim the technology works, and it should be allowed as evidence at trial. Law professor Hank Greely explains the state of the technology and the ethical questions surrounding its use. Writing this week in the Proceedings of the National Academy of Sciences, Greely and co9lleagues examine using functional magnetic resonance imaging (fMRI) to examine the activity in the human brain while a test subject was looking at pictures of other people. The researchers found that while they often could tell whether or not the test subject had been previously exposed to an image, the test had a very high rate of false positives. "Although subjective memory states can be decoded quite accurately under controlled experimental conditions, fMRI has uncertain utility for objectively detecting an individual's past experiences," they wrote.

We'll talk about the study, and about the idea of using brain imaging as a form of lie detector. What role, if any, should such techniques play in the courtroom?