Brain regional homogeneity and its association with age and intelligence in typically developing youth

Accelerated synaptic pruning and weakening of short-range functional connectivity are characteristic of adolescent brain development. Based on these structural microscopic and system-level functional changes, it was hypothesized that regional homogeneity (ReHo) may decrease with age in the developing brain, and a differ-ential association between ReHo and cognitive performance was expected to depend on age. ReHo maps of typically developing participants were provided by the Attention-Deficit/Hyperactivity Disorder (ADHD)-200 Preprocessed repository. Intelligence quotient was evaluated using the Wechsler Intelligence Scale for Chinese Children-Revised and Wechsler Abbreviated Scale of Intelligence at Peking University and New York University, respectively. Correlations between ReHo and age were examined, along with the interaction effects of ReHo and age on intelligence quotient (IQ), in 121 typically developing youth aged 8-14 years. Of the 400 ROIs tested, ReHo in 105 brain regions was significantly correlated with age (p < 0.05, false discovery rate-corrected), among which 102 showed that ReHo decreased with age. In addition, ReHo in 18 brain regions was negatively corre-lated with age at Bonferroni-corrected thresholds (p < 0.05), and most associations were observed in the pre-frontal cortex. The interaction analyses suggested that higher ReHo was associated with higher IQ in children, whereas this association was attenuated or reversed in adolescents (p < 0.05, uncorrected). ReHo decreased with age in the developing brain and was differentially associated with intelligence in children and adolescents.