Figure 1.
Growth charts of social visual engagement for typically-developing children (TD) relative to children diagnosed with autism spectrum disorder (ASD). (A) Fixation to eyes, mouth, body, and object from 2 until 24 months in TD males (in blue) and (B) in males with ASD (in red). Contrary to a hypothesis of congenital reduction in preferential attention to the eyes in ASD, infants with ASD exhibit mean decline in eye fixation from 2 until 24 months of age. Hypothesized (C) and actual (D) mean eye fixation curves are plotted in blue for TD children and in red for children with ASD. Longitudinal change in fixation to (E) eyes; (F) mouth; (G) body; and (H) object regions. Dark lines of each color represent mean growth curves, while light lines indicate pointwise 95% confidence intervals. Top panel in each section plots percent fixation over time; middle panel plots change in fixation over time (the first derivative, in units of % change per month); and the bottom panel plots F value functions for pointwise comparisons of fixation and change in fixation between groups. Pointwise comparisons with F values greater than Fcrit (for 1,34 dof = 4.13, P = 0.05, marked by arrowhead on F ratio axis) are shaded in medium gray (for comparison of fixation data) and light gray (for comparison of change-in-fixation data).