Hauptinhalt

FB Kolloq SoSe2025: Martin Schnürch

„Pinocchio disassembled: A hierarchical diffusion-model account of the cognitive cost of lying”

Veranstaltungsdaten

Dr. Martin Schnürch, Universität Mannheim
„Pinocchio disassembled: A hierarchical diffusion-model account of the cognitive cost of lying”

Telling a lie is more cognitively demanding than telling the truth. Support for this notion comes, inter alia, from instructed-lying paradigms showing that untruthful responses tend to be slower than truthful responses. Conventional measures of the cognitive cost of lying are typically collapsed across response categories and ignore error trials and accuracy, instead focusing solely on average latencies of correct truthful and untruthful responses. To overcome these limitations and better disentangle the mechanisms underlying response behavior in instructed-lying paradigms, I propose to analyze data using a drift diffusion model. The diffusion model considers the full response-time distributions for both correct and error responses, thus making use of all available information. Using a Bayesian hierarchical diffusion model to analyze data from variants of the Sheffield Lie Test, I find that the model’s drift-rate parameter provides a reliable measure of the cognitive cost of lying. Moreover, model results show that truth-versus-lie instructions elicit a response bias that may confound conventional measures that fail to account for it. Thus, hierarchical diffusion modeling constitutes a promising approach for analyzing data from instructed-lying paradigms and provides intriguing avenues for future research into the cognitive mechanisms underlying deception.