Page 103 - Demo

Facial Mimicry and Metacognition in Facial Emotion Recognition1014specific hypotheses about alterations in perceived emotional intensity ratings related to social anxiety or autistic traits, explorative analyses on this rating variable can be found in the Supplemental Materials. Furthermore, the simplicity ratings provided insights in how difficult emotion recognition with this novel stimulus set was perceived. Overall, happy expressions received the highest simplicity ratings (M = 69.39, SD = 27.15), followed by surprised expressions, (M = 62.51, SD = 25.35), fearful expressions (M = 50.93, SD = 26.19), angry expressions (M = 45.05, SD = 25.66), neutral expressions (M = 36.42, SD = 33.74), and sad expressions (M = 36.19, SD = 25.56). Some might consider differences in simplicity between emotion categories as potential confound in predicting emotion recognition accuracy (i.e., higher simplicity ratings might systematically be linked to more accurate choices). Yet, these differences have been proposed to arise due to factors that are inherently linked to the specific emotional expression, such as a higher familiarity with increased exposure in daily life (Calvo et al., 2014; Nummenmaa & Calvo, 2015). We aimed for higher ecological validity in examining facial emotion recognition by using spontaneous and non-acted expressions in the current study. Controlling for simplicity, in contrast, would detach our results from emotion recognition in everyday life, which is why we decided against it. Lastly, participants filled in the Liebowitz Social Anxiety Scale (LSAS) (Liebowitz, 1987) and the Autism Spectrum Quotient (AQ; see Measurements section) (BaronCohen et al., 2001). Upon completion of the experiment, participants were given a written and verbal debriefing about the goal of the study and were reimbursed. In total, the experiment lasted around 55 minutes, including instructions and the attachment of the facial electromyography electrodes. MeasurementsFacial Electromyography (fEMG)Facial electromyography (fEMG) was measured on the left side of the face of all our participants, following the guidelines of Fridlund and Cacioppo (Fridlund & Cacioppo, 1986). To specify, two reusable 4 mm Ag/AgCl surface electrodes were placed over the Corrugator Supercilii region, which allowed us to measure mimicry responses to sad, fearful, and angry expressions (according to the EMFACS definition) as well as to happiness expressions (as shown in previous research). Other two electrodes were placed over the Zygomaticus Major region, which allowed us to measure mimicry responses to happy expressions. Additionally, a ground electrode was added on the top of the forehead. The signal