Concealed Information and its Effect on Heart Rate, Respiration Rate, and Electrodermal Activity

Abstract

Testing the efficacy of polygraphs can be especially difficult because it is hard to make someone lie in the same way one would during a criminal polygraph. We designed a simplified way of creating guilt and detecting deception. In this study, 22 UW-Madison students participated, and their respiratory rate, heart rate, and electrodermal activity were monitored to assess any significant changes from a negative control or baseline value. Using a simplified procedure, subjects were given a concealed information test (CIT). The CIT involved showing test subjects a two minute PowerPoint with words and pictures, having the subject choose a closed bag and examine an object inside, and view another two minute PowerPoint similar to the first but in a different order. It was expected that upon seeing the words that correlated with the object they “stole”, the subjects would respond with a measurable physiological change. Both respiratory and heart rates did not show a statistically significant change between the negative control and experimental conditions; however, electrodermal activity did show a statistically significant change (p-values: 0.00941, 0.0162, and 0.0157) for all three words used to probe for concealed information. These findings show that while time-intensive procedures for assessing guilty knowledge are more sensitive, the procedure featured in this study could be improved and used to replace the commonly used methods, or used as a pilot study to assess for any significance in a new physiological marker that hasn’t been studied.