Nonautomatic emotion perception in a dual-task situation

Are emotions perceived automatically? Two psychological refractory period experiments were conducted to ascertain whether emotion perception requires central attentional resources. Task 1 required an auditory discrimination (tone vs. noise), whereas Task 2 required a discrimination between happy and angry faces. The difficulty of Task 2 was manipulated by varying the degree of emotional expression. The stimulus onset asynchrony (SOA) between Task 1 and Task 2 was also varied. Experiment 1 revealed additive effects of SOA and Task 2 emotion-perception difficulty. Experiment 2 replicated the additive relationship with a stronger manipulation of emotion-perception difficulty. According to locus-of-slack logic, our participants did not process emotional expressions while central resources were devoted to Task 1. We conclude that emotion perception is not fully automatic.