Psychobiological Correlates of Instructed Deceptive Responding: An Exploratory EEG Study

Intentional deceptive responding under laboratory instructions provides an experimental model for investigating the cognitive mechanisms involved in producing false responses, although it does not fully capture the complexity of real-world deception. Although deception has important implications for social functioning and has been widely studied, identifying reliable indicators that cannot easily be concealed remains a major challenge. In the present study, we investigated frontal EEG activity during intentional instructed deception and examined its association with stress-related and affective traits. The study included 86 healthy adults (M age = 26.97 years, SD = 9.42) who completed standardized self-report measures assessing depression (BDI), anxiety (BAI), perceived stress (PSS), and everyday deceptive behavior (LiES). A subsample of 48 participants subsequently completed a controlled truth–deception task while EEG activity was recorded from frontal scalp electrodes, providing an indirect measure of frontal electrophysiological activity. Absolute spectral power was analyzed across beta, alpha, theta, and delta frequency bands. The findings indicated that anxiety was positively associated with self-reported deceptive behavior, whereas depression and perceived stress were not significantly related to deception tendencies. EEG analyses suggested an increase in right-frontal scalp theta power during instructed deceptive responding, particularly through significant modulation of theta activity in the right hemisphere; however, later multilevel analysis showed it is a rather less specific activation appearing irrespective of the hemisphere. The increase remained significant when relative power was analyzed, indicating that the finding was robust to normalization of spectral power. Together, these findings suggest that instructed deceptive responding was associated with changes in frontal EEG oscillatory activity that are broadly consistent with mechanisms previously linked to executive control and conflict monitoring; however, because recordings were obtained using a low-density consumer EEG device during overt verbal responding, these interpretations should be considered exploratory. In this view, our study investigates habitual deceptive tendencies with affective traits and state-dependent EEG modulation during instructed deception, and our results could contribute to the understanding of emotion–cognition interactions in decisions involving uncertainty, social evaluation, and strategic information control.