Eye Gaze Patterns of Young Children with Autism and the Broader Autism Phenotype During a Dynamic Social Interaction Task

Background: Atypical facial fixation patterns have been discovered in older individuals with autism (Pelphrey et al., 2002); however, much less is known about facial fixation behavior in children with autism at 36-months of age and younger. The small body of research that exists suggests that atypical face processing and facial fixation behavior is evident even in young children with autism (Dawson et al., 2004; Klin & Jones, 2008; Webb et al., 2006). Given these findings, studying facial fixation patterns in the siblings of children with autism is important because these children are at a greater risk of developing autism, and thus this is a population that can be evaluated for signs of autism from birth.

Objectives: To examine the fixation behavior of 36-month-old siblings of children with autism (high-risk group) in comparison to typically developing (TD) children (low-risk group) during a social interaction task with a caregiver in an effort to improve characterization of autism and the broader autism phenotype (BAP).

Methods: We examined the facial fixation behavior of 36-month-old siblings of children with autism (n = 28) and a typically developing comparison group (n = 25). All 53 children were part of a larger study and were followed longitudinally starting at 6 months of age. At 36 months of age, the children were grouped into best-estimate clinical diagnostic categories (including Autism/ASD, BAP or TD)) using data from the ADOS-G, ADI-R, Mullen Scales of Early Learning, and behavioral observations. Each study participant sat in front of the eye-tracking monitor and engaged in a live interaction (peek-a-boo) with his/her caregiver via a closed-circuit computer monitor. Fixation patterns during the interaction were compared between clinical diagnostic groups.

Results: Children diagnosed with Autism/BAP (n=10) displayed an atypical fixation pattern, focusing less on the upper region of the face (eyes: p < 0.05) and more on areas around the face (hands: p < 0.05) than TD children in both the high-risk and low-risk groups (n = 41). The siblings of children with autism who were found to be typically developing (n = 19) showed similar fixation behavior to TD control children (n = 22) for upper face, lower face, and hand regions (ps > 0.341).

Conclusions: Our findings suggest that young children diagnosed with autism and the BAP display atypical attention to faces when interacting with a caregiver compared to TD children in both the high-risk and low-risk groups at 36 months of age. Importantly, the results of this study demonstrate that differences in facial fixation behavior are not a general feature of children at risk for autism; rather, those high-risk siblings who were diagnosed as typically developing displayed typical fixation behavior. The results of the current study also indicate that there is a close relationship between social impairment and facial fixation behavior, supporting the hypothesis that gaze patterns at a very early age are related to social development. Consequently, eye-tracking technology within the context of the infant sibling research design is useful for characterizing early signs of autism and the BAP.