Despite significant advances in deception detection in forensic psychology using polygraphy, there is a lack of empirical evidence for the potential of deception detection in ordinary situations of simple conversation where contact and invasive measurement methods are not appropriate. To address this issue, we used two strategies: 1) a non-invasive observation of facial thermal changes and gaze behaviour under deceptive and truthful conditions and 2) combination of prepared and unprepared questions during an interview. We used a within-person experimental design where responses from 16 participants were recorded, using infrared thermal imaging (fITI) and eye-tracking to measure the dependent variables (i.e., thermal changes of the nose, cheeks and forehead and gaze fixations of the interviewer’s eyes). The independent variables were veracity (truth vs. lie) and type of scenarios (prepared vs. spontaneous). Mixed-effects regression models were used to analyse the effect of lying and effect of preparation. Veracity did not significantly modulate any physiological marker, but forehead and cheek temperature were significantly modulated by the different scenario conditions in the expected direction. Multiple comparisons revealed a significant modulation of eye fixations by both the lying and scenario conditions, with eye fixations being lower in the spontaneous scenarios and higher in the prepared deceptive conditions. The results underline the significant influence of arousal and cognitive load on individual variability in all dependent variables and provide essential insights for future research into the physiological and behavioural aspects of deception detection. This study lays the foundation for the use of fITI and eye-tracking under certain experimental conditions of an ordinary conversation in content and emphasises the role of (un)preparation for the accuracy of deception detection.

Lie detection research comparing manual and automated coding of linguistic cues is limited. In Experiment 1, we attempted to extend this line of research by directly comparing the veracity differences in manual coding and two coding software programs (Text Inspector and Linguistic Inquiry and Word Count [LIWC]) on the linguistic cue “total details” across eight published datasets. Mixed model analyses revealed that LIWC showed larger veracity differences in total details than Text Inspector and manual coding. Follow-up classification analyses showed that both automated coding and manual coding could accurately classify honest and false accounts. In Experiment 2, we examined if LIWC’s sensitivity to veracity differences was the result of honest accounts including more redundant (repeated) words than false accounts as LIWC—but not Text Inspector or manual coding—accounts for redundancy. Our prediction was supported, and the most redundant words were function words. The results implicated that automated coding can detect veracity differences in total details and redundancy, but it is not necessarily better than manual coding at accurately classifying honest and false accounts.

Slovenská akadémia vied vykonáva špičkový základný výskum, dlhodobý strategický a aplikovaný výskum a vývoj a poskytuje prístup k vedeckej infraštruktúre.

Detecting deceptive information in job interviews is a major challenge for improving personnel selection validity. Traditional interviewer-based methods for detecting applicant faking are limited in accuracy, highlighting the need for reliable techniques to enhance detection and minimize suboptimal hiring decisions. This study aimed to (a) investigate functional infrared thermal imaging (fITI), a non-invasive method for measuring facial temperature, to determine whether cognitive load and arousal during direct deception induce facial thermal changes indicative of faking; and to (b) develop an automated framework for processing infrared recordings, accounting for head movements and physiognomic differences. A within-person experimental design was conducted with 27 participants in simulated job interviews under five conditions: baseline, rehearsed truth, rehearsed lie, spontaneous truth, and spontaneous lie. A high-sensitivity infrared camera recorded thermal changes on the nose, forehead, and cheeks. Our dynamic feature extraction approach enabled robust temporal analysis despite naturalistic head movements. Linear mixed-effects models revealed no significant overall effect of faking; however, rehearsal and interaction effects were significant. Nasal temperature was higher in rehearsed than spontaneous responses and in spontaneous lies than spontaneous truths, while forehead and cheeks temperatures remained stable. Findings suggest that cognitive load from rehearsed and spontaneous questioning influences nasal thermal changes during faking.

Gaze behavior is a critical component of social interaction, reflecting emotional recognition and social regulation. While previous research has emphasized either situational influences (e.g., deception) or stable individual differences (e.g., attachment avoidance) on gaze patterns, studies exploring how these factors interact to shape gaze behavior in interpersonal contexts remain scarce. In this vein, the aim of the present study was to experimentally determine whether the gaze direction of individuals differs, with respect to their avoidant orientation, under changing situational conditions, including truthful and deceptive communication towards a counterpart. Using a within-person experimental design and the eye-tracking methodology, 31 participants took part in both rehearsed and spontaneous truth-telling and lie-telling tasks. Consistent with expectations, higher attachment avoidance was associated with significantly fewer fixations on emotionally expressive facial regions (e.g., mouth, jaw), and non-significant but visually consistent increases in fixations on the upper face (e.g., eyes) and background. These findings indicate that stable dispositional tendencies, rather than situational demands such as deception, predominantly shape gaze allocation during interpersonal interactions. They further provide a foundation for future investigations into the dynamic interplay between personality and situational context in interactive communicative settings.