Published papers

第1 回・第2 回「ジェンダーと 教育を考える会」の記録 ―小平麻衣子先生と共に話し合うことから― より

Emotions are accompanied by physical reactions, such as facial expressions and heart rate changes. This paper focuses on facial skin blood flow (SkBF) as an index of the autonomic nervous system. Facial SkBF is a unique indicator compared to heart rate or sweating because it is related to facial temperature and facial color changes. The SkBF does not react uniformly in all areas of the face and has different reactivity in each part of the face, such as the forehead, cheek, or nose. In several previous studies, the time window for the analyses was about 30 seconds or more, however, focusing on short-term rapid responses, e.g. 5 seconds, is critical for clarifying the mechanisms of mental disorders related to facial SkBF and clinical intervention.

Facial skin blood flow (SkBF) has attracted attention as an autonomic indicator because it influences facial colour, which informs others of emotional states, and facial temperature related to social anxiety. Previous studies have examined the facial SkBF in people experiencing emotions; however, facial SkBF changes in the observers of emotions are poorly understood. Our study clarified facial SkBF changes related to observing others’ emotions by comparing the changes with other physiological indices. Thirty healthy participants (24 females; mean age: 22.17) observed six types of facial expressions (neutral, angry, and embarrassed expressions with and without facial blushing) and rated the emotional intensity of the other person. We measured their facial SkBF, finger SkBF, and cardiac RR interval as they made their observations. Facial SkBF generally decreased in relation to observing emotional faces (angry and embarrassed faces) and significantly decreased for angry expressions with blushing. None of the participants noticed blushing of facial stimuli. For the RR interval and finger SkBF, there was no variation depending on the observed facial expressions, although there was a general increase related to observation. These results indicated that facial SkBF is sensitive and reactive to emotional faces—especially angry faces with blushing— compared with other autonomic indices. The facial SkBF changes were not related to either RR interval changes or the intensity rating, suggesting that facial SkBF changes may be caused by vasoconstriction and have potential functions for our emotions. The decrease in facial SkBF may have a role in calming observers by preventing them from adopting the same emotional state as a person with intense anger. These findings clarify daily facial SkBF fluctuations and their relationship with our emotional processing in interpersonal situations.