Subjective and model-estimated reward prediction: association with the feedback-related negativity (FRN) and reward prediction error in a reinforcement learning task.

In this study, we examined whether the feedback-related negativity (FRN) is associated with both subjective and objective (model-estimated) reward prediction errors (RPE) per trial in a reinforcement learning task in healthy adults (n=25). The level of RPE was assessed by 1) subjective ratings per trial and by 2) a computational model of reinforcement learning. As results, model-estimated RPE was highly correlated with subjective RPE (r=.82), and the grand-averaged ERP waves based on the trials with high and low model-estimated RPE showed the significant difference only in the time period of the FRN component (p<.05). Regardless of the time course of learning, FRN was associated with both subjective and model-estimated RPEs within subject (r=.47, p<.001; r=.40, p<.05) and between subjects (r=.33, p<.05; r=.41, p<.005) only in the Learnable condition where the internal reward prediction varied enough with a behavior-reward contingency.