Monetary gain and loss expectations enhance response inhibition to angry faces: EEG evidence

Previous studies have shown that monetary incentives can improve response inhibition when emotional stimuli are used as background distractors. However, investigations of response inhibition to an emotional stimulus when it is the target have rarely been performed. The present study aimed to explore the effects of monetary gain and loss expectations on response inhibition to angry facial expressions using an emotional Stop-signal task, combining event-related potentials (ERPs) and event-related spectral perturbations (ERSPs) to explore the underlying neural mechanisms. Incentive cues (gain, loss, or neutral) were followed by a neutral face target (Go trial) or neutral face turning into an angry face target (Stop trial), with response contingent feedback then presented. Behavioral results revealed that monetary loss anticipation accelerated go responses, but comparable stop signal response times were found between monetary gain and loss conditions. EEG results revealed that monetary incentive cues modulated the ERP components and cue delta in the anticipatory stage, with a stronger effect in the incentive conditions relative to the neutral condition. In the task stage, the Go-P3 and Stop-P3 components tracked the response execution and response inhibition processes in the Go and Stop trials, respectively, aligning with behavioral performance. For the feedback period, the feedback-related negativity amplitudes, as well as the neural oscillations (fb-delta/theta), tracked both the incentive valence and the outcome type. These results suggest that monetary gain and loss cues enhanced response inhibition to emotional facial information, with monetary loss conditions having stronger effects than the gain conditions in the cue-P2 and target-P3 components.