Conflict in a word-based approach-avoidance task is specific to positive valence

Across species, valence and motivational direction are inextricably linked (organisms usually approach good things and avoid bad things), and overriding these links is experienced as conflicting. However, not all negative emotions are linked to avoidance motivation. Therefore, positive conflict (avoiding positive stimuli) should produce conflict more reliably than negative conflict (approaching negative stimuli). In the present ERP study, we tested this assumption by contrasting positive and negative conflict. We presented participants with positive and negative words that they had to approach or avoid. Consistent with our proposition, positive conflict created stronger behavioral and neural effects than negative conflict; Positive conflict prolonged reaction times more than negative conflict did. Event-related potentials related to conflict (N450 and conflict slow potential) were only sensitive to positive conflict.