Reward prediction-error promotes the neural encoding of episodic learning

Abstract

Reward prediction-error carries significant implications for learning, facilitating the process by influencing prior knowledge and shaping future expectations and decisions. However, the electrophysiological mechanism through which reward prediction-error impacts learning remains incompletely understood. This study aimed to investigate the neural characteristics of reward prediction-error and its effect on recognition memory using Event-Related Potentials (ERPs). Behavioral results indicate that unsigned reward prediction-error indeed enhances recognition performance, with reaction times being slower in “remember” responses compared to correct predictions. The ERP findings conform to a three-stage model of reward prediction-error, suggesting that physical salience is swiftly detected (N1), followed by the processing of positive reward prediction-error (Feedback-Related Negativity, FRN), and ultimately, unsigned reward prediction-error or outcome evaluation (P300). Moreover, early physical salience signals were associated with subsequent “know” responses, while later unsigned reward prediction-error signals predicted subsequent recognition performance. This study not only revealed the neural processing mechanisms of reward prediction-error but also explored its impact on recognition performance, particularly familiarity or recollection processing.