Figure 5. Fiber covariance network features are associated with executive function in youth.

(A) Univariate analyses using GAMs that controlled for sex, motion, and image quality revealed that executive function was associated with higher FDC in 13 of 14 networks. The coloring of the fixels of the covariance networks is based on the partial R² scores of executive function. Multiple comparisons were accounted for using the FDR (q < 0.05).

(B) Bar graph depicting the effect size of executive function for each network (partial R²). These partial R² magnitudes were highest in association networks such as the fornix/cingulum (hippocampus), the parietal part of the superior longitudinal fasciculus (SLF), and the superior longitudinal and arcuate fasciculi (networks 2, 5, and 10).

(C) We tested whether the multivariate signature of the fiber covariance networks could predict executive function above and beyond sex and data quality by comparing a full model to a null model excluding the 14 covariance networks. We found a significant difference between a reduced covariate-only model (i.e., sex, motion, and image quality) and a full model that included both the fiber covariance networks and covariates (F = 6.56, df = 14, p < 0.001). The proportion of variance in executive function explained by the 14 covariance networks was R² = 0.327, resulting in a good correspondence executive function and predicted executive function.

(D) The association between executive function and FDC is shown for the covariance networks with the highest partial R² scores. EF, executive function; CC, corpus callosum; CST, corticospinal tract; CP, cerebellar peduncle; Int, internal; Sup, superior.