Task difficulty and response complexity modulate affective priming by emotional facial expressions

In this study we used an affective priming task to address the issue of whether the processing of emotional facial expressions occurs automatically independent of attention or attentional resources. Participants had to attend to the emotion expression of the prime face, or to a nonemotional feature of the prime face, the glasses. When participants attended to glasses (emotion unattended), they had to report whether the face wore glasses or not (the glasses easy condition) or whether the glasses were rounded or squared (the shape difficult condition). Affective priming, measured on valence decisions on target words, was mainly defined as interference from incongruent rather than facilitation from congruent trials. Significant priming effects were observed just in the emotion and glasses tasks but not in the shape task. When the key-response mapping increased in complexity, taxing working memory load, affective priming effects were reduced equally for the three types of tasks. Thus, attentional load and working memory load affected additively to the observed reduction in affective priming. These results cast some doubts on the automaticity of processing emotional facial expressions.