Law enforcement officials pride themselves on being able to spot a liar, but even a lie detector can be fooled from time to time. So now, Texas researchers are turning to a widely used medical device to look for a lie in the brain.
It is commonly used in law enforcement-polygraph or lie detector tests. They react to different emotions through changes in the body like heart rate, blood pressure, and skin sweatness. But hook up a good liar or someone without a conscience to one of these tests. "You're not going to get anxious and the polygraph will be either ineffective or less effective," says Peter Fox, a Neurologist at UT San Antonio.
One possible solution is MRI's. Unlike the polygraph, MRI's don't rely on emotion. "This is entirely based on the additional mental work needed to tell lies and keep track of your lies," says Fox.
Researchers in San Antonio are conducting studies using MRI's to compare brain activity during truth telling and lying. An area of the brain called the frontal lobe becomes more active when someone's lying. This is the part of the brain that involves memory.
"And we believe this is the subjects keeping track of what they told us before and making sure that their lies, their deceptions, weren't too transparent," says Fox.
Will MRI's eventually have a place in the court system? "You can't rule it out, and medicine takes huge leaps, but they're going to really have to be able to show a real scientific basis for it," says Susan Reed, District Attorney in Bexar County.
Researchers say the first way they may use the MRI to test for a lie will likely be to see if people are faking injuries to scam insurance companies, but don't look for that test soon. It could take months or even years to make the technology perfect.