Modular Segregation of Structural Brain Networks Supports the Development of Executive Function in Youth

TL;DR

This study shows that as children and adolescents age, their brain's structural networks become more modular and integrated, which in turn supports improvements in executive functions.

Contribution

It reveals how structural brain network modularity and integration develop during youth and relate to executive function improvements.

Findings

Structural modules become more segregated with age.

Strengthening of hub edges enhances network integration.

Modular segregation and integration are linked to better executive performance.

Abstract

The human brain is organized into large-scale functional modules that have been shown to evolve in childhood and adolescence. However, it remains unknown whether structural brain networks are similarly refined during development, potentially allowing for improvements in executive function. In a sample of 882 participants (ages 8-22) who underwent diffusion imaging as part of the Philadelphia Neurodevelopmental Cohort, we demonstrate that structural network modules become more segregated with age, with weaker connections between modules and stronger connections within modules. Evolving modular topology facilitated network integration, driven by age-related strengthening of hub edges that were present both within and between modules. Critically, both modular segregation and network integration were associated with enhanced executive performance, and mediated the improvement of executive functioning with age. Together, results delineate a process of structural network maturation that supports executive function in youth.