title: Facial Mimicry and the Processing of Facial Emotional Expressions
Creators: name: Kühne, Maria
Publisher: name: Universität Bern
Year: 2021
Subjects: subject: 150 Psychology

description: In social interactions, facial expressions make a major contribution to our daily communication as they can transmit internal states like motivations and feelings of our conspecifics. In the last decades, research has revealed that facial mimicry plays a pivotal role in the accurate perception and interpretation of facial expressions. Embodied simulation theories claim that facial expressions are automatically mimicked, thereby producing a facial feedback signal, which in turn activates a corresponding state in the motor, somatosensory, affective and reward system of the observer. This activation - in turn - facilitates the processing of the observed emotional expression and hence supports the understanding of its meaning. Research on the influence of facial mimicry on the perception of emotional expressions is, to a large extent, driven by facial mimicry manipulation studies. Especially the classical facial mimicry manipulation method introduced by Strack, Martin, and Stepper (1988) has become a popular and established method. Here participants have to hold a pen in different positions with the mouth inducing a smiling or a frowning expression. The present thesis assessed the influence of facial mimicry on cognitive processes by means of this classical facial mimicry manipulation method. In three projects, I investigated the impact of (1) facial mimicry on the automatic processing of facial emotional expressions, (2) facial mimicry on the working memory for emotional expressions, and (3) facial mimicry manipulation on an impaired processing of emotional expressions in patients with Parkinson’s disease (PD).

In a first project, the impact of facial mimicry manipulation was measured by electrophysiological recordings of the expression related mismatch negativity to unattended happy and sad faces. The findings reveal that the automatic processing of facial emotional expressions is systematically influenced by facial mimicry. In the second project, I assessed the behavioral performance during a facial emotional working memory task while the mimicry of participants was manipulated. Findings of this project highlight that working memory for emotional expressions is influenced by facial mimicry. Finally, in the third project, I investigated the link between the reduced facial mimicry in PD patients and their impaired ability to recognize emotional expressions. For this purpose, I compared the data of PD and healthy individuals during the performance of an emotional change detection task while undergoing facial mimicry manipulation. Although healthy participants show a typical pattern of facial mimicry manipulation influence, PD patients do not profit of the applied manipulation.

The results of the present thesis demonstrate that facial mimicry is an indispensable part in our daily social interaction as it affects the processing of emotions on a perceptual as well as a cognitive level. I showed that facial mimicry influences the automatic processing of - as well as the working memory for - observed facial emotional expressions. Furthermore, the empirical evidence of the third project suggests that not only facial mimicry is reduced in patients with PD but rather that the whole process of facial feedback processing is impaired in those individuals. These results demonstrate the applicability of the classical facial mimicry manipulation method and further highlight the importance of research on the influence of facial mimicry on cognitive processing as our ability to understand the emotional expressions of our conspecifics and thus our social interaction depends on an intact facial mimicry processing.