Positive emotion speeds up conflict processing: ERP responses in an auditory Simon task.

Emotions signal the particular relevance of situations, threatening or rewarding, and influence perception and behaviour accordingly. Research to date has predominantly investigated the impact of negative emotional stimuli. However, rapid reactions to positive emotional stimuli are similarly adaptive. Here, we tested the influence of positive emotional stimuli on attentional control, which enables reacting to conflicting stimulation. We therefore presented positive emotional and neutral words in an auditory Simon task. Reaction times revealed faster resolution of conflict when target stimuli were positive compared to neutral words. Also, emotion modulated the first conflict-sensitive event-related brain potential, a negativity at 420 ms, indicating an influence on early stages of conflict processing. These results complement recent data on negative stimuli and suggest that positive stimuli are equally salient. The rapid impact on attentional control is evolutionary highly adaptive as it reduces the time that conflict yields an organism incapable of responding to reward-signalling stimuli.