关键词: 社会性发展迟滞, 表情识别, 类别知觉

Abstract: Social delay refers to the one with normal cognitive development but their social development was inferior to peers', such as self-concerned on the interpersonal relationship, incapable to feel sympathy for others, and the mal-adaption on social behavior. The study take the college students with social delay as experimental group and the normal students as compared group, to clarify the differences of their recognition on facial expressions, to investigate the processing characteristics of facial expression on college students with social delay and analyze the possible reasons, as well as to confirm the effect of categorical perception for emotional faces. The MorphMan technology were used to produce the continua on which each face expressions differed in signal intensity. On the experiment 1, the participants were asked to recognize the basic facial expressions (sad, angry, fear, surprise, happy, disgust) with changing intensity. The result shows that the performance of facial expression recognition are getting better with the intensity increased, except for fear emotion. The college students with social delay have longer reaction time for those basic facial expressions than their normal peers, and lower accuracy on angry emotion. Additionally, the students with social delay having the best performance on sad emotion. The categorical perception paradigm are adopted on experiment 2. On the AB-X discrimination task, participants viewed facial expressions A and B that differed by 20% intensity increments, and to discriminate the image X is identity with A or B. The result shows that the social delay group are significant slower on discrimination than their normal peers. And confirmed the categorical perception effect of facial expressions that although participants are presented with a series of facial expressions distributed along a continuum between emotions, observers perceive these stimuli as belonging to discrete categories, the result also demonstrated the between-category advantage. After the AB-X task, all the students completed an identification task, they identified the expression of morphed facial image(happy-sad, angry-sad, angry-fear). The social delay group are significant slower to identify the expression that contained angry emotion than their normal peers. Then, fitted logistic function P=c+(d-c )/(1+e– (x–a)/b) for each continuum of each individual and using Matlab.R2017b to calculate the intensity of morphed facial expression x when P=0.5. The result shows that all the category boundaries (x) are shifted on social delay group, not much proportions of sadness is enough for them to identify, while the larger proportions of anger are required. The present experiments provide the evidence that processing ability of facial expressions on students with social delay are significant poorer than their peers, the reaction time are much longer and their performance on angry emotion are impaired. Notably, they got the perceptual bias on sadness. The individual with social delay are very likely to respond by avoidance in the face of negative signal on social interactions, and this social style may cause the lower self-efficiency and the learned helplessness, an overwhelming feeling of sad may generated by this way. On the opposite, they are very unlikely to taking control measures to deal with the negative signal on social interactions, somehow, it may leads to the inability to express their anger. The study focus on the processing characteristics of facial expressions on college students with social delay, it provides the direction for intervention. Transfer the attribution on social failure from innate and stable factors(e.g. capability) to innate and unstable factors(e.g. efforts), the reattribution training can significant moderating the sense of helpless and reducing the occurrence of helplessness interpretation. Moreover, the social skills coaching help to improve the performance on social interaction for students with social delay, reduce the avoidant social behaviors and promoting on self-efficiency.

Key words: social delay, recognition of facial expression, categorical perception