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 adoles-cence, 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, adoles-cents 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 advanced 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 have implications for the design of customized educational/clinical interventions to optimize individual developmental strategies. HighlightsO_LISubstantial decreases in functional homotopy along the unimodal-transmodal axis observed from childhood to adolescence, with associative areas experiencing a more pronounced decrease. C_LIO_LIDynamic shifts in the correlation between functional homotopy and intelligence in developmental stages. C_LIO_LIIndividuals with a higher IQ demonstrate a significantly faster development of hemi- spheric specialization or differentiation. C_LIO_LIThe distinct patterns in the development of functional homotopy in different IQ- groups underscore the complex interaction between brain maturation and intelligence. C_LI