Chapter 5 - Detecting Deception Using Ocular Metrics During Reading

Abstract

We have proposed an innovative approach to detect deception that makes use of evoked pupillary response in conjunction with eye movements during reading. We first provide an overview of the psychophysiological bases of pupil dilation, describe how evoked pupillary responses have been used to detect deception, and describe how eye movements have been used to study reading behaviors. From this, a rationale is given for how pupillary response and eye movements during reading can be used to detect deception. We tested our approach in two laboratory and two field studies, in which we asked participants to read and respond to three types of statement: neutral, relevant to a crime not committed, and relevant to a crime committed. Measures of reading behaviors and evoked pupil responses were used in discriminant function analyses. Overall, over 85% of cases were classified correctly in the laboratory studies and 77.7% of cases were classified correctly in one of the field studies. The test was ineffective with poor readers in the other field study. The use of pupillary response and eye movements during reading has promise as a new tool for the detection of deception.