(Don’t) take it personally: EEG markers of preparing lies about autobiographical questions

• Semantic cues indicated the abstract need to lie about following personal questions • ERPs revealed enhanced attention and general preparation prior to actual deception • Centro-parietal alpha power was reduced after lie vs. truth cues • Multivariate EEG decoding and individual-level analyses performed far above chance • EEG markers of preparing lies might stimulate innovative ways of lie detection For millennia, people have been interested in detecting lies and understanding their neurocognitive underpinnings. As a novel approach, the present preregistered EEG study investigates mental processes of preparing a lie, continuing our previous study (Schnuerch, R., Schmuck, J., & Gibbons, H. 2024. Cortical oscillations and event‐related brain potentials during the preparation and execution of deceptive behavior. Psychophysiology, 61 12, e14695.) in a more realistic scenario. While participants previously categorized written words denoting furniture and clothing correctly or incorrectly, based on preceding truthful and untruthful color cues, the current task required answering autobiographical, highly self-relevant, questions from four semantic categories. Thirty-two participants were instructed to lie exclusively to questions of one predefined category. A preceding cue indicated the category and therewith the abstract need to lie or to tell the truth regarding the subsequent question, which was not exactly known before. Conceptually replicating Schnuerch et al. (2024), we found increased amplitudes of fronto-central P2, P3a, Contingent Negative Variation and parietal P3b along with reduced centro-parietal alpha power following lie compared to truth cues. Thus, lie cues increased attentional and general preparatory processes that should facilitate deceptive responses toward self-relevant stimuli. Further, multivariate decoding and a blind identification of the individual lie categories based on ERPs and alpha power performed substantially above chance. Overall, such EEG markers of enhanced mobilization of cognitive resources in the period leading up to deception might stimulate developments of innovative ways of lie detection based on the preparation rather than execution of deceptive responses.