A systematic review and meta-analysis of atypical visual attention towards non-social stimuli in preschoolers with autism spectrum disorder.

Research on attention towards non-social stimuli in preschoolers with autism spectrum disorder (ASD) has increased over the past decade; however, findings have been inconsistent. It has been suggested that stimuli relating to common circumscribed interests (CIs) elicit more attention than non-CI related stimuli. This meta-analysis synthesizes results from 31 studies that compared attention towards non-social stimuli in children with ASD under the age of five with typically developing (TD) controls using eye-tracking. Additional subgroup analysis comparing studies that employed non-social stimuli related to CIs frequently reported in adults with ASD to studies using non-CI related stimuli were conducted. Meta-regressions with age, sex, stimulus dimension, nonverbal DQ, and symptom severity were conducted. Results show small (g = 0.39) but significantly higher attention towards non-social stimuli for the ASD group. However, when studies were split based on stimulus type no significant differences for non-CI related stimuli was found. Meanwhile studies employing CI related stimuli reported significant large effects on attention allocation (g = 0.69). None of the conducted regressions reached significance. The findings show increased non-social attention in children with ASD is driven by CI related content rather than a general non-social attentional bias. The findings and future research directions are discussed.