The Effect Of Emotional Expressions On The Perception Of Visual Direct And The Joint Visual Attention In Autism

Autism spectrum disorder has serious social communication disorders, mainly manifested in the lack of eye contact, facial expression recognition difficulty and joint visual attention defect, etc. Emotional facial expressions and gaze direction is the important way that individual understand the others’emotion, intention, interest and attention focus. Joint visual attention refers to the process that the individual follows another’s gaze direction to make the two individuals pay attention to the same object at the same time.Previous researches had shown that emotional facial expressions and gaze direction had mutual influence for normal individual. The study of normal suggested that facial expressions affected individual’s ability to identify the gaze direction and to gaze following. With happy and angry expressions, individuals had a larger cone of gaze(range of gaze deviations perceived as direct); when with fear and sad expressions, individuals had a smaller cone of gaze, they were more likely identified the averted gaze. However, no researchers explored whether facial expressions had influence on identifying and tracking eye gaze direction of autism. Therefore, this study first explores the effect of emotional expressions on the perception of visual direct and the joint visual attention in autism, help to understand the ability of processing face information, and provide related theoretical basis for the training and education of autism.Experiment 1 respectively presents male and female models of three expressions (happy, neutral and fear) with five gaze directions (left 10 pixels,4 pixels, direct, right 4 pixels, right 10 pixels) to normal and autism children, participants asked to identify the models’ gaze direction. The results suggests that cone of gaze for happy is larger than neutral and fear in autism children; the cone of gaze for neutral is larger than fear in autism children. These results suggest that emotional facial expressions affect the autism’s gaze direction perception, under the influence of facial expression, autism also shows the approach-avoid oriented motivation.Experiment 2 uses the eye-tracking technology and the Posner’s space clues paradigm to investigate the role of three facial expressions (happy, neutral, fear) in joint visual attention in normal and autism children. The study suggests that autism and normal children all have a significant GCE(gaze cuing effect), that is the reaction time of valid conditions is shorter than the invalid conditions. But the pattern of facial expressions affect the joint visual attention is different with autism and normal children. The fastest react of normal children is in neutral expressions, the fear expressions follow, and the slowest react is in happy expressions. While autism children only under the condition of the happy expressions show significant GCE, there are no GCE in neutral and fear expressions.The results show that the facial expressions influence autism’s ability to identify gaze direction, there is no difference between the autism and typically developing children’s joint visual attention. Facial expressions affect the typically developing children’s joint visual attention, emotional facial expressions are more likely to hold children’s attention, so slow down the speed toward the goal, the shortest reaction time in neutral expression. But the influence of facial expression on joint visual attention of autism is different from the typically developing children. Happy expressions have an important influence on autism, autism shows significant gaze cuing effect in happy expression conditions, while there are no significant gaze cuing effect in fear and neutral expression conditions. Above all, autism children have no significant defects in identifying and following gaze direction. But under the influence of facial expressions, autism children have an abnormal phenomenon which is different from typically developing children.