For years, the polygraph has been the gold standard when detectives question a suspect. They are 90 percent accurate. Which means it's possible for people telling the truth to fail, and for good liars to pass the test. Scientists have discovered that when lies are formulated, the face may be calm, but the brain gets a workout because the MRI can spot more activity in the brain of a liar.
"This represents areas in the brain, and these red dots are specific areas that demonstrate activation when one was lying. "I think eventually it will develop into the judicial system where we can see some high-level crimes potentially be sought-after for this technique," says Scott Faro M.D. at Temple University in Philadelphia. Dr. Faro says they will probably be testing the MRI lie detector for at least 5 years before it could be available to crime fighters.