Eye Movements as Indicators of Deception: A Machine Learning Approach

Abstract

Gaze may enhance the robustness of lie detectors, but remains under-studied. This study evaluated the efficacy of AI models (using fixations, saccades, blinks, and pupil size) for detecting deception in Concealed Information Tests across two datasets. The first, collected with Eyelink 1000, contains gaze data from a computerized experiment in which 87 participants revealed, concealed, or faked the value of a previously selected card. The second, collected with Pupil Neon, involved 37 participants performing a similar task but facing an experimenter. AI models (XGBoost) achieved accuracies of up to 74\% in a binary classification task (Revealing vs. Concealing) and 49\% in a more challenging three-classification task (Revealing vs. Concealing vs. Faking). Feature analysis identified saccade number, duration and amplitude along with maximum pupil size as the most important for deception prediction. These results demonstrate the feasibility of using gaze and AI to enhance lie detectors and encourage future research that may improve on this.Gaze may enhance the robustness of lie detectors, but remains under-studied. This study evaluated the efficacy of AI models (using fixations, saccades, blinks, and pupil size) for detecting deception in Concealed Information Tests across two datasets. The first, collected with Eyelink 1000, contains gaze data from a computerized experiment in which 87 participants revealed, concealed, or faked the value of a previously selected card. The second, collected with Pupil Neon, involved 37 participants performing a similar task but facing an experimenter. AI models (XGBoost) achieved accuracies of up to 74\% in a binary classification task (Revealing vs. Concealing) and 49\% in a more challenging three-classification task (Revealing vs. Concealing vs. Faking). Feature analysis identified saccade number, duration and amplitude along with maximum pupil size as the most important for deception prediction. These results demonstrate the feasibility of using gaze and AI to enhance lie detectors and encourage future research that may improve on this.