Analyzing Fluctuations in Heart Rate, Respiration, and Perspiration as Physiological Indicators of Deception

Abstract

This experiment tested the hypothesis that there are physiological differences that manifest when a person tells a lie compared to when they tell the truth. It was predicted that when a person lies, their sweat production would increase, while their respiratory rate and heart rate would decrease. Thirty subjects were asked to tell four truths and one lie by looking at a set of colored cards and answering questions about what card they chose. The subjects were tested for their EDA conductance, respiratory rate, and heart rate and those values were compared to baseline. It was found that there was a significant increase in sweat conductance when they lied compared to when the subjects told the truth. Heart rate and respiratory rate showed no significant difference when compared with the baseline measurements. The conclusions drawn from this study might help us develop instruments which are more sensitive and reliable at detecting falsehoods in comparison to the polygraph test.