Publications (3)1.75 Total impact
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ABSTRACT: Our goal was to evaluate an alternative to current methods for detecting deception in security screening contexts. We evaluated a new cognitive-based test of deception that measured participants' ocular-motor responses (pupil responses and reading behaviors) while they read and responded to statements on a computerized questionnaire. In Experiment 1, participants from a university community were randomly assigned to either a "guilty" group that committed one of two mock crimes or an "innocent" group that only learned about the crime. Participants then reported for testing, where they completed the computer-administered questionnaire that addressed their possible involvement in the crimes. Experiment 2 also manipulated participants' incentive to pass the test and difficulty of statements on the test. In both experiments, guilty participants had increased pupil responses to statements answered deceptively; however, they spent less time fixating on, reading, and rereading those statements than statements answered truthfully. These ocular-motor measures were optimally weighted in a discrimination function that correctly classified 85% of participants as either guilty or innocent. Findings from Experiment 2 indicated that group discrimination was improved with greater incentives to pass the test and the use of statements with simple syntax. The present findings suggest that two cognitive processes are involved in deception-vigilance and strategy-and that these processes are reflected in different ocular-motor measures. The ocular-motor test reported here represents a new approach to detecting deception that may fill an important need in security screening contexts. (PsycINFO Database Record (c) 2012 APA, all rights reserved).Journal of Experimental Psychology Applied 04/2012; 18(3):301-13. · 1.75 Impact Factor
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ABSTRACT: Purpose. There were three objectives of this study: (1) To assess the possibility of using pupil diameter as an index of deception in the context of a comparison question polygraph test. (2) To determine if pupil diameter would make a significant contribution to an optimal multivariate classification equation in combination with the traditional predictor variables used in field polygraph practice. (3) We explored the possibility of replacing one or more of the traditional predictor variables with pupil diameter.Methods. We used a laboratory mock crime experiment with 24 participants, half of whom stole $20 (US) from a secretary's purse. Participants were tested with a comparison question test modelled after standard field practice. Physiological measures were taken with laboratory quality instrumentation. Features were extracted from the physiological measures. Those features were subjected to a number of different statistical analyses.Results. Innocent participants showed larger increases in pupil diameter in response to probable-lie questions than to relevant questions. Guilty participants did not show differential responding to the question types. The additional of pupil diameter to a multivariate classification model approached, but did not reach significance. Subsequent analyses suggest that pupil diameter might be used to replace the traditional relative blood pressure measure.Conclusions. Pupil diameter was found to be a significant predictor variable for deception. Pupil diameter may be a possible replacement for the traditional relative blood pressure measure. Additional research to explore that possibility would seem to be warranted.Legal and Criminological Psychology. 08/2009; 14(2):279 - 292.
Conference Proceeding: Eye Movements and Pupil Size Reveal Deception in Computer Administered Questionnaires.[show abstract] [hide abstract]
ABSTRACT: An oculomotor test is described that uses pupil diameter and eye movements during reading to detect deception. Forty participants read and responded to statements on a computerized questionnaire about their possible involvement in one of two mock crimes. Twenty guilty participants committed one of two mock crimes, and 20 innocent participants committed no crime. Guilty participants demonstrated speeded and accurate reading when they encountered statements about their crime and increases in pupil size. A discriminant function of oculomotor measures successfully discriminated between guilty and innocent participants and between the two groups of guilty participants. Results suggest that oculomotor tests may be of value for pre-employment and security screening applications.Foundations of Augmented Cognition. Neuroergonomics and Operational Neuroscience, 5th International Conference, FAC 2009 Held as Part of HCI International 2009 San Diego, CA, USA, July 19-24, 2009, Proceedings; 01/2009