Up until now, the known signs which gave away a liar have been blushing, staring at the ground and the person's agitation, but a new study shows that liars can be detected by observing the changes in gastric physiology as well.

The study, carried out by The University of Texas demonstrates a clear link between the act of lying and a significant increase in gastric arrhythmia.

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, the researchers recruited sixteen healthy volunteers to undergo simultaneous electrogastrogram (EGG) and electrocardiogram (EKG) recordings for three periods

The researchers found that both lying and truth telling affected cardiac symptoms, while the act of lying was also associated with gastric symptoms. The EGG showed a significant decrease in the percentage of normal gastric slow waves when the subject was lying that corresponded to a significant increase in the average heart rate during the same situation.

"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.