Functional MRI still not accepted as evidence in criminal trials

Washington Post : After three days of pretrial arguments about the validity of functional magnetic resonance imaging (fMRI) scans of a man on trial for murder, a judge in Maryland ruled that the tests are not admissible as evidence. Whereas a traditional MRI just shows the brain’s structure, an fMRI provides images of activity in the brain. Some neuroscientists believe that fMRI scans can distinguish when a person is lying from when they are telling the truth. Several studies have returned better than 90% accuracy at identifying lies. However, another study has shown that it is easy to “trick” the scan, because the machine does not necessarily recognize different kinds of activity. As with polygraphsâmdash;the traditional “lie detector,” which isn’t accepted as evidence in courtâmdash;the lack of conclusive proof of consistent accuracy suggests that fMRI results will continue to be inadmissible in criminal trials.