Variations in Cortical Functional Gradients Relate to Dimensions of Psychopathology in Preschool Children.

Abstract

OBJECTIVE: It is unclear how the functional brain hierarchy is organized in preschool children and whether alterations in the brain organization are linked to mental health in this age group. Here, we assessed whether preschool children exhibit a brain organizational structure similar to older children, how this structure might change over time and whether it might reflect mental health. METHOD: This study derived functional gradients using diffusion embedding from resting state fMRI data of 4.5-year-old (N=100, 42 male participants) and 6.0-year-old (N=133, 62 male participants) children from the longitudinal Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort. We then conducted partial least squares correlation analyses to identify the association between the impairment ratings of different mental disorders and network gradient values. RESULTS: The main organizing axis of functional connectivity (i.e., principal gradient) separated the visual and somatomotor regions (i.e., unimodal) in preschool children, while the second axis delineated the unimodal-transmodal gradient. This pattern of organization was stable from 4.5 to 6 years of age. The second gradient separating the high- and low-order networks exhibited a diverging pattern across mental health severity, differentiating dimensions related to attention-deficit/hyperactivity disorder and phobic disorders. CONCLUSION: This study characterized for the first time the functional brain hierarchy in preschool children. A divergence in functional gradient pattern across different disease dimensions was found, highlighting how perturbations in functional brain organization can relate to the severity of different mental health disorders.