"Hot" Affect-Related Aspects in Emotional Information Processing: The Role of Facial Muscle Responses in the Direct and Indirect Processing of Emotion Categories

The present study investigated the involvement of facial muscle responses in the indirect and direct processing of emotional facial expressions. Five discrete emotion categories were used, and we assessed both facial muscle and behavioral responses on a trial-by-trial basis. Experiment 1 tested facial muscle activation of clearly visible stimuli in an emotion categorization task. We observed emotion-specific facial muscle responses and corresponding behavioral categorization effects, providing evidence for the specificity of facial muscle activation. By contrast, under masked indirect presentation conditions in which emotional facial expressions were presented as primes in an emotion misattribution procedure, a specific pattern of emotion-congruent and cross-category behavioral misattributions was observed (in line with Rohr et al., 2015, 2018). Multilevel analyses in Study 2 suggest that an emotional reaction feeds into the behavioral decision, as indicated by differential activation of the frontalis lateralis in response to angry faces. Thus, the present study provides evidence that facial muscle responses contribute to behavioral decisions under masked indirect processing conditions. The different pattern of effects in both studies suggests that facial muscle responses index different processes, depending on the processing conditions: sensorimotor simulation in direct processing conditions and emotional reactions in masked indirect processing conditions. We discuss the implications for models that aim to account for facial muscle activity in response to emotional facial expressions.