December 3, 2004. Copyright 2004, Graphic News. All rights reserved

Lie Detection by Brain Scan
By Mark Rutter

LONDON, December 3, Graphic News: Imagine a world where a machine can read your thoughts. Where a quick, simple brain scan will reveal whether you are really telling the truth. The plot of numerous science fiction stories? It might be time to think again after researchers in the United States say that an fMRI (functional magnetic resonance imaging) scan of the brain can tell whether a person is lying.

FMRI provides a live image of brain activity and is used routinely in medicine to diagnose brain tumours. By employing this scanning technique, Dr Scott Faro and his co-workers at Temple University in Philadelphia were able to spot unique areas in the brain associated with either telling lies or the truth.

The research told a meeting of the Radiological Society of North America that six people were asked to shoot a toy gun with blank bullets before lying about what they had just done. Four other people were asked to tell the truth. In the first study of its kind, the participants were then questioned on what had happened, as well as on unrelated events for control purposes.

Seven regions of the brain - areas also involved in emotional responses - including the frontal and temporal lobes became very active during lying. During truth telling, there was no great activation of any part of the brain, but four areas did show low levels of response.

The fMRI was able to distinguish truthful responses from deceptive ones in every case. But, as the number of participants in the tests was very low, much more research will be required before fMRI is accepted as a reliable lie detector.

The researchers also administered a traditional polygraph test to the participants. This technique measures three human responses: breathing, blood pressure and sweating. Although the polygraph proved to be 100 percent accurate in recognising when a participant was being honest or not, doubts over its accuracy have been expressed in the past. It is well known that some people fail the test as a result of becoming nervous about being tested, while others are able to lie undetected by learning to cheat the polygraph.

As a result, Dr Faro thinks that fMRI might be more reliable than the polygraph for lie detecting. Nevertheless, he cautions that it is too early to tell if fMRI is resistant to cheating, although the results do suggest the ability to alter the brain patterns detected might be beyond conscious control. The present cost of fMRI would preclude its routine use as a lie detector but if proven to be accurate it could be of great benefit in questioning suspected major criminals.
/ENDS