Do you want to detect a liar? Just look at his stomach!

Changes in gastric physiology are a better indicator than standard polygraph methods in distinguishing between lying and telling the truth, a study released by the University of Texas suggests.Polygraphs use electrocardiograms (ECGs) to measure changes in heart rate and sweating to detect lies. But researchers say the stomach and gastrointestinal tract are also extremely sensitive to stress, and this mind-stomach connection may betray even the best liars.

To test their hypothesis that the gastrointestinal tract is uniquely sensitive to mental stress because of the communication between the central nervous system and the enteric nervous system, researchers at the University of Texas Medical Branch recruited sixteen healthy volunteers to undergo simultaneous electrogastrogram (EGG) and electrocardiogram (EKG) recordings for three periods, according to Science Daily.

In the study, researchers measured changes in the stomach using an electrogastrogram (EGG) in 16 healthy volunteers while they did nothing, told the truth, or told a lie. The participants also had a simultaneous ECG to measure changes in heart rate. An ECG records electrical signals of the heart muscle; an EGG records electrical signals of the muscles of the stomach.

"We concluded that the addition of the EGG to standard polygraph methods has clear value in improving the accuracy of current lie detectors," said Pankaj Pasricha, MD, University of Texas Medical Branch. "The communication between the big brain and the little brain in the stomach can be complex and merits further study." A.M.