Beyond monetary incentives: Deception exhibits context-dependent neural patterns in the mPFC, dlPFC, and Caudate...

Contextual factors profoundly influence deceptive decisions. While research on deception has advanced significantly, studies have predominantly focused on deception incentivized by monetary gain. The present fMRI study employed a novel group-painting task to dissociate the neural correlates of deception across four conditions: the beneficiary (self vs. other) and the incentive type (monetary rewards vs. social-affective goals). Behaviorally, deceptive behavior reached its peak in self-serving monetary contexts. Neurally, key regions exhibited context-dependent dissociations. The medial prefrontal cortex (mPFC) showed heightened activation and context-specific representations in the Self-Affection context, and reduced activity in frequent deceivers when making both deceptive and honest decisions. In contrast, the dorsolateral prefrontal cortex (dlPFC) was more engaged in the Self-Money context (vs. Self-Affection) and when making honest decisions, with frequent deceivers exhibiting attenuated dlPFC/caudate differentiation between lying and truth-telling trials. While the caudate nucleus lacked condition-specific activation, it selectively responded to monetary settings and outcomes in the self-serving context. Representational similarity analyses further revealed that individual differences in deception frequency and magnitude were encoded in distributed neural patterns. Together, these findings reveal deception is not a unitary process, its frequency and underlying neural circuitry are shaped by contexts. Key brain regions of deception exhibited context-dependent responding patterns, suggesting these areas, while consistently involved in (dis)honesty, may serve dissociable functional roles across contexts.