MRIs as lie detectors

Filed in archive Investigational on September 29, 2005

Sounds like an expensive polygraph test:

Neuroscientists using magnetic resonance imaging (MRI) scans - which provide a computer-generated picture of the brain's workings - have developed a near 100 per cent accurate formula to separate lies from the truth, a report in the journal Nature reveals.

The researchers believe that their test is now ready for real-life scenarios.

The test works by monitoring the frontal lobes of the brain. When somebody lies, their brain inhibits them from revealing the truth, and this makes the frontal lobes more active. By analysing the brain activity during scenarios in which subjects tell both truths and lies, they have developed an algorithm that can identify each response with 99 per cent accuracy. The team gave volunteers an envelope containing two playing cards and $20. Subjects could keep the money if they lied convincingly in the tests.