Behavioral approach and reward processing: results on feedback-related negativity and P3 component.

This study examined the FRN, the P3, and individual differences in trait-BAS and trait-BIS in the context of reward expectation mismatch. A more negative FRN was predicted for higher vs. lower trait-BAS individuals and for higher vs. lower trait-BIS individuals. In the extinction-learning task, participants (N=102) chose between two response buttons to earn a maximum of points. In the acquisition phase, button 1 was continuously rewarded and button 2 was partially rewarded. In the extinction phase, one button was unexpectedly no longer rewarded. The FRN amplitude was more negative for higher vs. lower trait-BAS individuals and for lower vs. higher trait-BIS individuals within the extinction phase. The P3 was more positive in the extinction compared to the acquisition phase. Our results suggest that higher trait-BAS individuals have a more pronounced reward expectation mismatch.