MONDAY, Nov. 29, 2004 (HealthDayNews) -- Brain imaging with functional magnetic resonance imaging (fMRI) could one day prove more accurate than the polygraph in identifying people who are lying, according to a study presented Nov. 29 at the Radiological Society of North America annual meeting in Chicago.
Experts say that when people lie, they use different parts of the brain than when they're being truthful. These neurological changes can be observed by using fMRI, which measures ongoing alterations in brain activity.
"We were able to create consistent and robust brain activation related to a real-life deception process," study author Dr. Scott H. Faro, vice chairman of radiology and director of the Functional Brain Imaging Center and Clinical MRI at Temple University School of Medicine in Philadelphia, said in a prepared statement.
The study included 11 volunteers. Six of them were told to shoot a toy gun with blank bullets and then to lie about it while they were examined with fMRI and given a polygraph, which measures changes in respiration, blood pressure and perspiration.
In all cases, fMRI and the polygraph correctly identified liars and those telling the truth.
Faro noted that some people can "fool" the polygraph by regulating their physiological responses when being questioned. He said it's too early to tell if fMRI can also be "fooled."
"We have just begun to understand the potential of fMRI in studying deceptive behavior. We plan to investigate the potential of fMRI both as a stand-alone test and as a supplement to the polygraph with the goal of creating the most accurate test for deception," Faro said.
The American Polygraph Association has more about polygraph.