Eye Movement Study On Face Processing In Young Children With Autim:the Probe Into The Indicators Of Social Cognition Deficits

Autism spectrum disorders (ASD) are referred to as pervasive developmental disorders (PDD), characterized by pervasive deficits in social interaction, social communication, as well as unusual repetitive or restrictive behaviors and interests, the deficits in reciprocal social interaction is the core specific symptom. Autistic disorder (AD) is the most severe symptom in the spectrum. The increase in ASD prevalence highlights the urgency of paying close attention to early identification, diagnostic assessment, and well-founded interventions. Identifying impairments that distinguish young children with autism from typically developing children allows for early identification and sheds light on the nature of this disorder. The most important social cue is human face, which must be successfully recognised and interpreted as communicative signals. Efficient face processing is the core of social skills.To collect early signals of social cognition deficits of AD children, the current research adopted eye tracking technology to explore the features of face processing in young childern with autism. Preschool children with low-functioning autism were selected by pediatric specialist who serve in one tertiary special mental health hospital according to the Chinese classification and diagnostic criteria of mental disorders,3rd ed.(CCMD-â…¢) and the childhood autism rating scale (CARS). Chosen typically developing children as control group were matched with AD children on chronological age, visual acuity, and gender.Detecting a face within a scene is a crucial step in obtaining the social information expressed by the face. Therefore, in Study1including Experiment1to4, a serial of face detection and processing tasks were used to examine children's selective attention for face compared to non-face stimuli in the scene. The results showed a significant group difference with respect to detection speed to either faces or non-face objects. The autism children took significantly longer time to locate their fixations at the face or non-face targets than those of the control group; both groups showed an attentional bias for face versus non-face as shown they took less time to detect face than inanimate object in the natural scene; the semantic consistency between face and scene background affected face detection and processing of the autism children but not the control group.Study2investgated the face perception and processing in autism in which Experiment5and6was included. The results showed that autism children were able to distinguish face from non-face stimuli, however, they showed shorter face looking time compared to control group.Autism children fixated shorter in the eye region, especially, in contrast to the control group, autism children were not spontaneously biased to the left eye region. However, there was no difference in fixation times in the nonfeature areas and mouth region between individuals with or without autism disorder.Study3, comprised of Experiment7and8, investigated the attention and processing patterns of unfamiliar faces, highly familiar faces and repeated previously unfamiliar faces in autism. The results suggested that children with autism have the ability to distinguish familiar versus unfamiliar face, and they spent the same time to look at the familiar faces compared with normal children. Autism children spent shorter fixation times on all faces compared with normal children, they fixated shorter in the eye region, especially the left eye.Subsequent Study4, comprised of Experiment9,10and11, explored self-face recognition and processing. The results showed no differences between the fixation times of self and other's face in autism children while the fixation times of self-face was longer in normal children even it is not fixated with priority therefore, there might be a lack of self-other differentiation in autism children compared to the typically developing children, indicated that the development of self-aware in autism might be delayed. Autism children spent less time looking at the faces compared with normal children, no matter it is a self or other's face, they look less in the eye region, especially were less biased to the left eye region.The last study focused on the recognition and processing of facial expression through Experiment12to14. The results showed that, autistic children were able to recognize basic emotions, however, they fixated at the faces shorter than the control group when viewing different emotional faces, especially to the eye region. Similar to control group, autism children fixated significantly longer at fear faces than neutral faces, longer at eyes than mouths, indicated that their attention allocation patterns to different facial expressions were similar to those of normal children.Autism children showed a lack of fixations in the left eye region might result from their right hemisphere's deficits for facial information processing. Therefore, it is practicable to use the reduced fixation times in the eye region as an early behavioural indicator, as well as a marker to early indentify autistic individuals from people with high risk of suffering from autism.According to the face processing stages model, the current study demonstrated that autism children had more difficulties than typically developing individuals in face processing stages such as face selective attention, face recognition and understanding of facial cues. Nevertheless, autism children could be trained to be face processing experts base on this model.