Unravelling the origin of reward positivity: a human intracranial event-related brain potential study.

This article focuses on identifying the neural generator of the reward positivity (RewP), an event-related brain potential component linked to reinforcement learning and reward processing. Using intracranial electroencephalography (iEEG) recordings from 19 patients with refractory epilepsy undergoing invasive monitoring at Ghent University Hospital, the study aggregated data across participants to create a comprehensive brain map of RewP-related activity. Current source density analysis revealed that the left caudal anterior cingulate cortex (ACC) exhibited the strongest and statistically significant RewP-related signal, supporting the hypothesis that this region is the primary neural source of the RewP. Additional exploratory analyses found significant activity in the left dorsolateral prefrontal cortex, left frontomedial cortex, and left white matter, but none surpassed the caudal ACC in relevance. These findings provide direct intracranial evidence that the caudal ACC generates the RewP, contributing to ongoing debates about ACC function in reward processing.