Brain scans show significant differences in cranial activity when a person is lying compared to telling the truth, US researchers said yesterday.
Six volunteers were told to shoot a toy gun and then lie, saying that they hadn't done so, while three more volunteers told the truth about firing the gun. One person dropped out of the study.
The researchers used functional magnetic resonance imaging (fMRI) to study real time images of the subjects' brain activity while they made their testimony. The scans showed "a total of seven areas of activation in the deception (group), Dr Scott Faro, director of the Functional Brain Imaging Center at Temple University School of Medicine in Philadelphia said. His team found four areas of activity in the truth-telling arm.
The study found that lying takes more brain effort than telling the truth, Reuters reports.
Lying causes activity in the frontal part of the brain, including the medial inferior and pre-central areas, as well as the hippocampus and middle temporal regions and the limbic areas.
Telling the truth however causes activity in the frontal lobe, temporal lobe and cingulate gyrus.
Faro said that fMRI, while expensive, could prove worthwhile as a lie detector in important cases, such as questioning a terrorism suspect, or in a high-profile corporate crime case. But he noted that the Philadelphia study was small and limited in scope, as the subjects were not encouraged to try very hard to fool the machine. ®