How an uncertain cue modulates subsequent monetary outcome evaluation: an ERP study.

People avert uncertain situations more than certain ones, and the neural correlates of such acts have gained increasing attention in past decade. However, the electrophysiological bases of how subjects respond to uncertain cues, and how such cues affect subsequent outcome evaluations have rarely been explored. In the present study, participants completed a gambling task while their neural activities were recorded through electroencephalography. The results indicated that subjects were sensitive to the uncertain cue as represented by feedback-related negativity (FRN). This uncertain cue further enhanced the neural response to outcome evaluation represented by P200, FRN, and P300 temporally. The enhanced P200 outcome may reflect the negative bias of the emotional reaction, which is a reflection of uncertain deviation at an early stage. The discrepancies of differentiated feedback-related negativity between uncertain and certain condition indicated increased motivation or prediction error toward the outcome. Finally, the increased P300 amplitude under uncertain outcome compared with certain one, as well as its sensitivity to the valence of the outcome under uncertain condition, embodies the increased arousal of the affective response. Therefore, uncertain cue effects observed in the current study suggest that uncertainty induces a larger motivational/affective and expectation response toward outcome revelation.