关键词: 自闭症谱系障碍儿童, 面孔加工, 同龄偏向效应, 情绪

Abstract: Purposes: Autism spectrum disorder (ASD) is a generalized neurodevelopmental disorder. As a typical feature of children with autism, social disorder is of great clinical and practical value to study its social cognitive characteristics. A large number of studies have found that children with autism are specific to face processing, but they have not reached a consistent conclusion, which may be affected by the age of the faces of the materials. Normal individuals’ perception and memory of faces of the same age are better than those of different ages. This phenomenon is called own-age bias. Many studies have found that the normal population has the own-age bias, but the research on the own-age effect of ASD children are less. Therefore, the purpose of this study is to explore the own-age bias of ASD children in the process of face processing (Experiment 1). Moreover, the study intends to explore the influence of emotion to the own-age bias (Experiment 2). Procedures: We used visual tracking technology to explore the effect of the own-age bias in face processing of children with ASD. Experiment 1 recruited 19 ASD children and 23 biologically age-matched TD children as subjects. By freely watching 12 pictures of neutral faces of the same age (Children face) and 12 pictures of other age(Adult face), the children with ASD were tested whether there is a own-age bias of face processing. Each picture was presented for 4s and there was a 1s central calibration point presented between the pictures; Experiment 2 recruited 22 ASD and 25 TD children matched with their biological ages, and detect the influence of emotions on the own-age bias of ASD children’s face processing by asking them to freely watch happy, angry, and fearful faces. There were 16 pictures of each type of emotional face, and faces of the same age and faces of different ages are equally divided. Results: Experiment 1 found that TD children had significantly more dwell time on faces of other age than those of the same age; on the contrary, ASD children had more dwell time on faces of the same age. Experiment 2 found that the dwell time of ASD children on faces of the same age under anger and fear was significantly longer than the face of other age; there was no significant difference in the dwell time of TD children under the three emotions on faces of the same age and the other age. Further analysis of the gaze situation of ASD children on the eye or mouth area under emotional faces, the result showed that ASD children have a stable own-age bias in the eye area, and the dwell time and fixation count on the eyes of the same age are significantly greater than those of different age faces. Conclusions: The results indicates that ASD children have an own-age bias on the gaze processing of a neutral face. Additionally, emotions will affect the own-age bias of ASD children's gaze on faces. This effect does not exist under happy emotions, but exists under anger and fear emotions.

Key words: children with autism spectrum disorder, face processing, own-age bias, emotion