Structural brain network lateralization across childhood and adolescence

Developmental lateralization of brain function is imperative for behavioral specialization, yet few studies have investigated differences between hemispheres in structural connectivity patterns, especially over the course of development. The present study compares the lateralization of structural connectivity patterns, or topology, across children, adolescents, and young adults. We applied a graph theory approach to quantify key topological metrics in each hemisphere including efficiency of information transfer between regions (global efficiency), clustering of connections between regions (clustering coefficient [CC]), presence of hub‐nodes (betweenness centrality [BC]), and connectivity between nodes of high and low complexity (hierarchical complexity [HC]) and investigated changes in these metrics during development. Further, we investigated BC and CC in seven functionally defined networks. Our cross‐sectional study consisted of 211 participants between the ages of 6 and 21 years with 93% being right‐handed and 51% female. Global efficiency, HC, and CC demonstrated a leftward lateralization, compared to a rightward lateralization of BC. The sensorimotor, default mode, salience, and language networks showed a leftward asymmetry of CC. BC was only lateralized in the salience (right lateralized) and dorsal attention (left lateralized) networks. Only a small number of metrics were associated with age, suggesting that topological organization may stay relatively constant throughout school‐age development, despite known underlying changes in white matter properties. Unlike many other imaging biomarkers of brain development, our study suggests topological lateralization is consistent across age, highlighting potential nonlinear mechanisms underlying developmental specialization. Understanding biomarkers of brain development in typically developing populations is essential to identifying signatures of pathology. Further, with a vast literature supporting lateralization of neurological function, knowledge of mechanisms of brain lateralization in children is necessary to help further understand different neurological disorders. With contemporary studies highlighting the relevance and importance of white matter connectomics, we used whole brain tractography in a group of typically developing children and adolescents to assess structural brain network differences between the left and right hemispheres. Our results may provide a “baseline” of lateralization of struct