Pues según un investigador, cuando se miente se activan regiones específicas del cerebro. Regiones que se pueden detectar usando fMRI.
Faro and his colleagues asked six volunteers to fire a toy gun. The subjects then lay inside an fMRI scanner and lied about having fired the shot. They also received a polygraph test. Five more volunteers who did not shoot the gun were tested in the same ways to compare their responses.
Both tests caught out the liars and identified the truth-tellers in every case. The fMRI scan showed that specific areas of the brain were active during lying, including key parts of the frontal, temporal and limbic lobes. Overall, more areas of the subjects’ brains were activated when they lied.
Functional MRI picks up magnetic signals from oxygen atoms stuck to iron in the subject’s bloodstream. As brain activity increases, so too does blood flow, which carries more oxygen with it and boosts the signal strength. The technique, normally used for medical brain scans, can map activity in millimetre-sized parts of the brain.