社会性发展迟滞大学生的表情加工及其类别知觉

The Processing and Categorical Perception of Emotional Faces in College Students with Social Delay

本研究比较了社会性发展迟滞大学生与正常大学生的表情加工,探讨迟滞个体表情加工的特点及可能原因,还验证面部表情类别知觉效应。采用Morph情绪面孔实验发现:除恐惧情绪外,基本表情的强度越大被试对表情的识别越好;但迟滞个体的表情加工速度比正常个体慢,对愤怒的识别也更差;他们辨别混合表情中悲伤、愤怒的类别界线都发生偏移。迟滞个体的表情加工能力不如正常个体,并且对悲伤具有反应偏向,对愤怒存在加工缺陷。

Social delay （SD） refers to the someone with normal cognitive level but their social development is inferior to peers＇, such as being self-concerned on the interpersonal relationship, incapable of feeling sympathy, and the mal-adaption on social behavior. The study takes college students with SD as an experimental group compared with normal students to explore the differences of their recognition on facial expressions, the characteristics of expression processing, and to analyze the possible reasons, as well as to confirm the effect of categorieal perception for emotional faces. The Morph Man technology was used to produce the face expressions＇ continua that differed in signal intensity. In Experiment 1, participants were asked to recognize the basic facial expressions （sad, angry, fearful, surprised, happy, disgusted） with changing intensity. The result showed that, except for fear, the performance was getting better as the intensity increased. The SD group was significantly slower to react and had lower accuracy on angry emotion than their normal peers. Additionally, they performed the best on sad emotion. The categorical perception paradigm was adopted in Experiment 2. On an AB-X discrimination task, facial expressions A and B that differed by 20% intensity were presented. The participants were asked to tell whether the image X was the same as A or B. The result showed that the SD group was significantly slower to discriminate, and between-category advantages were demonstrated. The categorical perception effect was confirmed： even though a series of facial expressions distributed along a continuum between emotions, the observers sill perceived them as discrete categories. After the AB-X discrimination task, the participants were asked to identify the expressions of morphed facial images （happy-sad, angry-sad, angry-fearful） on an identification task. The SD group was significantly slower to identify the expressions that included the angry emotion. Then the category boundaries were calculated as the equal intensity on two facial expressions that morphed together. All the category boundaries were shifted on SD group, a smaller proportion of sadness was already enough to be identified, while for anger, a larger proportion was required for identification. The present experiments provided the evidence that processing ability of facial expressions on students with SD was significantly poorer than their peers. The reaction time was much longer and their performance on angry emotions was impaired. Notably, they got the perceptual bias on sadness and they were very likely to respond by avoiding the faces of negative signals on social interactions, and it might cause the lower self- efficiency and learned helplessness. An overwhelming feeling of sadness might be generated by this way. On the opposite, they were very unlikely to take control of the negative social interactions. This might lead to the inability to express their anger. The study focuses on the processing characteristics of facial expressions on college students with SD. It also provides the direction for intervention. Shifting the attribution on social failure from innate and stable factors to innate and unstable factors, the reattribution training can significantly moderate the sense of helplessness and reduce the occurrence of interpretation of helplessness. Moreover, social skill coaching may help to improve the performance on social interactions for students with SD, reduce the avoidant social behaviors, and promote self-efficiency.