Implicit processing of basic facial expressions in young children with autism: an eye-tracking study.

Background: Implicit processing of facial expressions by individuals serves as the foundation for accurate recognition and comprehension of emotional information. Difficulties in recognizing facial expressions was considered a typical characteristic of children with autism spectrum disorder (ASD). However, it remains unclear whether young children with autism have intact implicit processing of basic facial expressions. Aims: The present study utilized eye-tracking technology to assess the implicit processing performance of facial expressions in young children with ASD. Methods: A total of thirty young children with ASD and 30 age-matched children with typical development (TD) were recruited. All children completed an implicit emotional face task that used facial expression photographs of Chinese children. Results: No significant differences in accuracy rates between the two groups in the task. However, children with ASD showed shorter first fixation durations and lower proportion of fixation duration compared to TD children for all emotions. In addition, both groups showed a higher proportion of fixation duration and a greater number of fixations on the eye region of negative emotional faces (e.g., sad faces), as well as on the mouth region of happy faces. They showed a processing preference for the eye region of emotional faces and for fearful expressions. Conclusion: These findings indicate that children with ASD have atypical eye movements during the implicit processing of facial expressions, which may result in their difficulties in facial expression recognition.