1, 2, 3 crimes you're out: Ocular-motor methods for detecting deception in a multiple-issue screening protocol

Abstract

The ocular-motor deception test (ODT) uses pupil dilations and reading behaviors to detect deception. It questions examinees on two illicit activities but classifies deception for only one. Previous studies demonstrate that the ODT discriminates between truthful and deceptive individuals with over 80% accuracy. The present study considered a four-topic screening test and evaluated whether ocular-motor measures could discriminate between truthful and deceptive individuals and pinpoint the specific topic(s) answered deceptively. We recruited 180 participants from the community and the University of Utah. Sixty participants stole $20 (cash), 60 participants stole $20 and a VISA gift card (cash + card), and 60 participants were innocent (innocent). We asked participants about their involvement in four mock crimes: theft of $20, theft of a VISA gift card, vandalism of a parking kiosk, and filing a false police report. Cash participants were deceptive regarding cash statements, cash + card participants were deceptive regarding cash and card statements, and innocent participants were truthful regarding all statements. The computer compared reactions to cash, card, and vandalism statements to those on false report statements to detect deception. As predicted, cash and cash + card participants showed significant changes in ocular-motor measures to cash and both cash and card statements, respectively. A logistic regression model correctly classified 83.3% of innocent participants, 91.7% of cash participants, and 85.5% of cash + card participants. The model correctly classified 86.1%, 81.1%, and 88.3% of answers to the cash, VISA card, and vandalism items, respectively. The findings suggest that a multiple-issue ODT could be valuable in screening applications.