Voluntary Facial Mimicry Facilitates Embodiment of Emotion in Cortico-Limbic System
碩士 === 國立陽明大學 === 腦科學研究所 === 104 === Background: Smile can be elicited by intentional facial movement or by automatic mimicry. Smiling is critical for one’s well-being and social interactions. However, the neural mechanisms underpinning a smile and its interaction with cognitive control remain elusi...
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| Format: | Others |
| Language: | en_US |
| Published: |
2016
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| Online Access: | http://ndltd.ncl.edu.tw/handle/64247535191715534902 |
| Summary: | 碩士 === 國立陽明大學 === 腦科學研究所 === 104 === Background: Smile can be elicited by intentional facial movement or by automatic mimicry. Smiling is critical for one’s well-being and social interactions. However, the neural mechanisms underpinning a smile and its interaction with cognitive control remain elusive. The present study is to investigate the relationship between goal-directed control and the process of embodiment of smile. Method: This work used Magnetoencephalography (MEG) to demonstrate that cognitive control of positive facial expression altered brain activity and functional connectivity. Twenty right-handed healthy participants with no history of neurological or psychiatric disorders were recruited in the study. MEG is used in this study to investigate the interplay between the inferior frontal gyrus and amygdala while exercising active smiling (imitating smile and executing smile) and viewing a smiling face (observing smile). MEG signals were processed by region of interest analysis and Maximum Contrast Beamformer (MCB). The correlations were calculated among brain activation areas of interest. Result: We found that volitional top-down and goal-directed control mediate emotion-laden processing through dynamic coordination between cortical and subcortical regions with two phases. The findings of neuronal responses in the motor related region (precentral gyrus) at 125ms and mirroring related regions (inferior frontal gyrus /inferior parietal cortex) at 175ms demonstrate existence of automatic facial mimicry which implicates embodied simulation of social embodiment. Most importantly, we found the activations of the limbic system at 125ms and the dorsolateral prefrontal region at 175ms during volitional facial mimicry which involved in generating embodied emotion. Furthermore, the positive correlation between the inferior frontal gyrus and amygdala manifests at the initiation of facial mimicry and pinpoints a neural basis for emotional contagion. Conclusions: This study proposes an alternative neural mechanism of emotion embodiment which could be enhanced by a goal-directed cognitive process. Setting a goal as well as looking at the congruent scenery would facilitate the process of execution.
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