Intellectual ability and cortical homotopy development in children and adolescents

Functional homotopy, defined as the similarity between the corresponding regions of the two hemispheres, is a critical feature of interhemispheric communication and cognitive integration. Throughout development, the brain transitions from broadly connected networks in early childhood to more specialized configurations in adolescence, accompanied by increased hemispheric differentiation and integration. Using longitudinal data and a novel metric of functional homotopy, Homotopic Functional Affinity (HFA), we investigated the developmental patterns of functional homotopy and its relationship with intelligence. Our findings indicate a significant decrease in HFA with age, particularly in higher-order association networks. In addition, adolescents demonstrate stronger, predominantly negative correlations between HFA and intelligence, in contrast to younger children. In particular, individuals with superior intellectual ability experience accelerated decreases in HFA, indicating greater neural efficiency based on higher hemispheric specialization and differentiation. These findings provide evidence of the neural mechanisms that underlie cognitive development, emphasizing the dynamic interaction between hemispheric organization and intelligence. Our work may inform customized educational and clinical interventions for individual development.