Brain Scan Shows Differences in Truth, Lying
Mon Nov 29, 2:17 PM ET Science - Reuters
By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - Brain scans show that the brains of people who
are lying look very different from those of people who are telling
the truth, U.S. researchers said on Monday.
The study, using functional magnetic resonance imaging or fMRI, not
only sheds light on what goes on when people lie but may also provide
new technology for lie-detecting, the researchers said.
"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 Center at Temple University School of
Medicine in Philadelphia.
"There may be unique areas in the brain involved in truth-telling,"
Faro added at a news conference.
Faro and colleagues tested 10 volunteers. Six of them were asked to
shoot a toy gun and then lie and say they didn't 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 both to
a conventional polygraph and also had their brain activity imaged
using fMRI, which used a strong magnet to provide a real-time picture
of brain activity.
There were clear differences between the liars and the truth-tellers,
Faro's team told a meeting in Chicago of the Radiological Society of
"We found a total of seven areas of activation in the deception
(group)," he said. "We found four areas of activity in the truth-
Overall, it seemed to take more brain effort to tell the lie than to
tell the truth, 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 these are involved in
emotional responses, Faro said.
During a truthful response, the fMRI showed activation of parts of
the brain's frontal lobe, temporal lobe and cingulate gyrus.
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 has been documented that some people can fool a polygraph
using various techniques.
Using fMRI as a lie detector is expensive, but it may be worthwhile
in some cases -- such as trying to question a terrorism suspect, or
in a high-profile corporate crime case, Faro said.