Emotional expression and micro-expression recognition in depressive patients

Abstract

Facial expression is an important nonverbal act of human to express their emotion. It is the most prevalent indicator of emotion in human’s emotional study. Recently, how depressive people process the emotional information have received much interest. Previous studies have found that the ability to recognize facial expression in those people with major depressive disorder (MDD) is damaged. For example, they recognize negative expression slower, and show a negative bias. Furthermore, patients with depression have structural or functional abnormalities related to emotion-related brain regions. As a result, depressive patients may not accurately identify subtle changes on facial expression in social interactions. As a special form of subtle change, micro-expression is difficult to detect for healthy people. This is due to the short duration and weakened muscle movements of facial expressions. The duration of the micro-expression is between 1/25 and 1/5 s, and only part of the muscle movements are occurring, although sometimes it contains all muscle movements of the macro expression. Considering the damaged ability of depressive people to recognize facial expressions, this study aimed to examine whether micro-expression could be detected by depressive patients and how the recognition performance of micro-expression differs from that of macro expressions. According to the previous results of depressive people on the recognition performance of macro expression and brief expression, we speculate that their ability to identify micro-expression is also likely to be lower than healthy people, and this difference may be amplified due to the increased difficulty of recognition. In this study, macro expression recognition test, brief affect recognition test and micro-facial recognition test were used to examine the performance difference in identifying macro expression, brief expression and micro-expression between depressive patients and healthy people. The results showed that depressive patients recognized expression and micro-expression worse than healthy people, and both depressive patients and healthy people performed worse in micro-expression recognition than that in the macro expression recognition. It also showed that the HAMD score was negative correlated with the accuracy of expression and micro-expression recognition. Previous studies have focused on the recognition of common facial expression (i.e., macro-expression) in depressive patients, and this study had extended this line work to micro-expression recognition. These results indicated that the expression recognition deficiency of depressive patients is independent from the duration of facial expression, reflecting the severity degree of depression to some extent.