Fig. 5.

Structure–function model of the subsystem hierarchy associated with upper-level FB2f subsystem, SS1.1 (Figs. 2 and 4 and Dataset S4 C, E, and H). Only the most obvious and least controversial functions are attributed to lowest-level subsystems (20 for SS1.1), and these functions propagate up the hierarchy as they combine with other subsystems and become more general. Overall, current evidence suggests that SS1.1 (and mirror image SS2.1) is primarily associated with voluntary behavior control and cognition. For clarity, the gray matter regional composition of each subsystem is divided into four categories: CTX, CNU, TH, and HY. Region order in bottom-level subsystems is random. A complementary analysis of SS1.2 follows in Fig. 6. Abbreviations are in Dataset S1.