SCANS show the brains of people who are lying look very different from those of people who are telling the truth, a US study has found.Tests using functional magnetic resonance imaging, fMRI, not only shed light on what went on when people lied, but might also provide new technology for lie-detecting, the researchers said today.
"There may be unique areas in the brain involved in deception that can be measured with fMRI," said Dr Scott Faro, director of the Functional Brain Imaging Centre at Temple University School of Medicine in Philadelphia.
"There may be unique areas in the brain involved in truth-telling."
Dr Faro and his colleagues tested 10 volunteers.

Six were asked to shoot a toy gun and then lie and say they did not do it. Three others who watched told the truth about what happened. One volunteer dropped out of the study.
While giving their "testimony", the volunteers were hooked up to a conventional polygraph and also had their brain activity monitored using fMRI. It used a strong magnet to provide a real-time picture of brain activity.
There were clear differences between the liars and the truth-tellers, Dr Faro's team told a meeting in Chicago of the Radiological Society of North America.
"We found a total of seven areas of activation in the deception (group)," he said. "We found four areas of activity in the truth-telling arm."
Overall, it seemed to take more brain effort to tell the lie than to tell the truth, Dr Faro found.
Lying caused activity in the frontal part of the brain - the medial inferior and pre-central areas - as well as the hippocampus and middle temporal regions and the limbic areas.
Some of those areas were involved in emotional responses, Dr Faro said.
During a truthful response, the fMRI showed activation of parts of the brain's frontal lobe, temporal lobe and cingulate gyrus.
Dr Faro said the study was small and limited. Volunteers were not asked to try especially hard to deceive the equipment, he said - noting that it had been documented that some people could fool a polygraph using various techniques.
Using fMRI as a lie detector was expensive, but it might be worthwhile in some cases - such as trying to question a terrorism suspect, or in a high-profile corporate crime case, Dr Faro said.