Influence of Stimulus Layout and Social Presence on Deception-Related Eye Movements and Blinks in the Concealed Information Test

Over the past decades, eye movements and blinks have been integrated into Concealed Information Test (CIT) paradigms as indicators of deception. Recent findings suggested that fixation patterns in CITs depend on stimulus layout, particularly the distinction between sequential and simultaneous stimulus presentation. In addition, the impact of social presence on deceptive eye movements, critical for application of the CIT in real-world social settings, remains insufficiently examined. The present study addresses these issues through two experiments. In both, participants selected a card and had to reveal, conceal, or fake its value while all possible cards were displayed in pairs. Experiment 1 examined whether deceptive intentions could be differentiated using fixations and blinks, and extended previous findings on the effect of stimulus layout. Experiment 2 assessed the stability of deception-related eye movements and blinks across various levels of social presence (without, per video, being observed by a real person). Our findings replicate effects previously observed with simultaneous stimulus presentation of more cards, demonstrating how stimulus layout modulates deception-related eye movement patterns in CITs. The levels of social presence realised in this study did not significantly alter these patterns, indicating that deception-related eye movements and blinks in CITs remain stable under passive social presence.