Figure 1. Distribution of participants’ age and structural connectivity construction.

A, Age distribution (8.1–21.9 years) of 590 participants from the HCP-D dataset. B, Age distribution of participants from baseline (N = 3,949, 8.9–11.0 years) and 2-year follow-up (N = 3,155, 10.6–13.8 years) within the ABCD study. Using the Schaefer-400 atlas based S-A cortical axis map(Sydnor et al., 2021) (C), a cortical atlas comprising 12 cortical systems (D) was generated. In the S-A cortical axis map, cortical regions were ranked continuously along this axis, ranging from the lowest rank in the sensorimotor cortices to the highest rank in the association cortices. The 12-system cortical atlas was constructed by approximately equally dividing the cortex into 12 fractions according to the regions’ S-A cortical axis rank. For each scan, tractography was utilized to reconstruct the whole-brain white matter tracts with diffusion MRI dataset (E), and the large-scale white matter tracts connecting each pair of the 12 cortical systems were extracted and counted to generate the structural connectivity matrix (F). The connectivity matrix comprised 12 rows and 12 columns, with each element determined by the counts of white matter streamlines between every pair of systems, scaled by their respective cortical volumes. The matrix was arranged based on the average S-A axis cortical ranks of all regions within each system, from sensorimotor to association systems. HCP-D: the Lifespan Human Connectome Project Development; ABCD: the Adolescent Brain Cognitive Development; S-A: sensorimotor-association.