Evaluating the validity of eye-tracking tasks and stimuli in detecting high-risk infants later diagnosed with autism: A meta-analysis.

Gaze abnormalities are well documented in infants at elevated risk for autism spectrum disorder (ASD). However, variations in experimental design and stimuli across studies have led to mixed results. The current meta-analysis aimed to identify which type of eye tracking task and stimulus are most effective at differentiating high-risk infants (siblings of children with ASD) who later meet diagnosis criteria from low-risk infants without familial autism. We synthesized 35 studies that used eye tracking to investigate gaze behavior in infants at high genetic risk for autism before 2 years of age. We found that stimulus features, regions of interest (ROIs) and study quality moderated effect sizes across studies. Overall, dynamic stimuli and socially-relevant regions in the social stimuli (i.e. the target and activity of characters' shared focus) reliably detected high-risk infants who later develop ASD. Attention disengagement task and stimuli depicting interactions between human and nonhuman characters could identify high-risk infants who later develop ASD and those who have autism-related symptoms but do not meet the diagnostic criteria as well. These findings provide sensitive and reliable early markers of ASD, which is helpful to develop objective and quantitative early autism screening and intervention tools.