Frontoparietal and default mode network connectivity varies with age and intelligence

Background: Anticorrelated resting state connectivity between task-positive and task-negative networks in adults supports flexible shifting between externally focused attention and internal thought. Findings suggest that children show positive correlations between task-positive (frontoparietal; FP) and task-negative (default mode; DMN) networks. FP-DMN connectivity also associates with intellectual functioning across the lifespan. We investigated whether FP-DMN connectivity in healthy children varied with age and intelligence quotient (IQ). Methods: We utilized network-based statistics (NBS) to examine resting state functional connectivity between FP and DMN seeds in N = 133 7-25-year-olds (Mage = 15.80). Linear regression evaluated FP-DMN associations with IQ. Results: We detected NBS subnetworks containing both within- and between-network connections that were inversely associated with age. Four FP-DMN connections showed more negative connectivity between FP (inferior frontal gyrus and precentral gyrus) and DMN regions (frontal medial cortex, precuneus, and frontal pole) among older participants. Frontal pole-precentral gyrus connectivity inversely associated with IQ. Conclusions: FP-DMN connectivity was more anticorrelated at older ages, potentially indicating dynamic network segregation of these circuits from childhood to early adulthood. Youth with more mature (i.e., anticorrelated) FPDMN connectivity demonstrated higher IQ. Our findings add to the growing body of literature examining neural network development and its association with IQ.