Lying Makes the Brain Work More
But Brain Scans Can't Spot Liars -- Yet
Feb. 2, 2006 -- When people are lying, their brains work harder than people who tell the truth.
Lying leaves telltale traces on brain scans, report Feroze Mohamed, PhD, and colleagues in Radiology.
So can brain scans pick liars out of a lineup? Not yet. "Being a scientist, I am cautiously optimistic that one day we'll reach that [point]," Mohamed tells WebMD.
Mohamed works at Temple University as an associate professor of radiology and associate director of Temple's Functional Brain Imaging Center.
Mohamed and colleagues studied lies, honesty, and the brain. They found that "there are indeed regions in the brain that are unique to deception and that are unique to truth telling," Mohamed says.
Mohamed's study was small. It included 11 people, six of whom were assigned to go into a test room and fire a starter pistol with blank bullets.
The researchers questioned participants about the mock shooting, saying the participants had been spotted in surveillance tapes. The shooters were instructed to lie about their involvement. The innocent participants were told to be honest.
Meanwhile, participants got brain scans during the questioning. The scans used functional magnetic resonance imaging (fMRI).
Mohamed says he and his colleagues wanted to create a real experience so that the guilty people wouldn't be lying about lying. Instead, they would have smelled the gunpowder and felt the gun in their hands, Mohamed says.
"I mean, someone gives me a gun and I'm nervous. I don't even have to shoot," he says. "So we thought that in order to induce simulated lying, you need to create as close to a real-life scenario as possible."