Eye Movements as Indicators of Deception: A Machine Learning Approach

TL;DR

This study demonstrates that machine learning models using gaze features can effectively detect deception, achieving up to 74% accuracy, and highlights specific eye movement metrics as key indicators.

Contribution

The paper introduces a novel approach combining eye-tracking data with AI models to improve deception detection accuracy in Concealed Information Tests.

Findings

XGBoost achieved 74% accuracy in binary classification.

Saccade metrics and pupil size are key features for deception prediction.

Gaze-based AI models show promise for enhancing lie detection methods.

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 where 87 participants revealed, concealed, or faked the value of a previously selected card. The second, collected with Pupil Neon, involved 36 participants performing a similar task but facing an experimenter. XGBoost achieved accuracies 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, amplitude, and 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.