Appendix 4—figure 1. Proximity Index and its relation to behavioral phenotype in children with autism spectrum disorder (ASD) who were seen two times a year apart (the current figure depicts the initial (T1) visit).

Sample comprised 81 children with ASD who had valid eye-tracking recording and a complete set of behavioral phenotype measures a year after the baseline (T2). The PI for this paired longitudinal cohort was established using an age-matched reference group of 29 Typically Developing (TD) children. PI was obtained at T1 and its correlation with the behavioral phenotype measures was assessed at the same time (T1). Loadings on the latent component were derived using PLS correlation analysis. The cross-correlation matrix included the Proximity Index (PI) on the imaging side A and three behavioral variables B. The behavioral matrix accounted for two domains of autistic symptoms as assessed by ADOS-2, Verbal and Preverbal Cognition (VPC) from the PEP-3, and the Adaptive Behavior Composite Score from the VABS-II. Error bars represent the bootstrapping 5th to 95th percentiles. Results that were not robust are indicated by a gray boxplot color. PI at baseline was positively correlated with developmental and adaptive functionng at baseline.