Topographical functional correlates of interindividual differences in executive functions in young healthy twins

Executive functions (EF) represent a set of high order cognitive abilities that enable goal-directed behavior by controlling lower level operations. In the brain, those functions have been traditionally associated with activity in the Frontoparietal Network (FPN), but recent neuroimaging studies have challenged this view in favor of more widespread cortical involvement. In the present study, we aimed to explore whether the functional patterns of network reliance at rest differentiate individuals as a function of their EF performance. Furthermore, we investigated whether such differences are driven by environmentally as compared to genetic factors. For this purpose, resting state functional magnetic resonance imaging (rs-fMRI) data and the behavioral testing of 453 twins from the Colorado Longitudinal Twins Study (LTS) were analyzed. Separate indices of EF performance were obtained according to a bifactor unity/diversity model, distinguishing between three independent components representing: Common EF (cEF), Shifting (SHI)-specific and Updating (UPD)-specific abilities. Through an approach of step-wise in silico network lesioning of the individual functional connectome, we show that interindividual differences in EF are associated with different dependencies on neural networks at rest. The integrity of the networks of higher EF individuals are most affected by loss of nodes in cognitive-related networks, whereas individuals with lower EF scores are most affected by loss of nodes in sensory networks. Furthermore, these patterns show evidence of mild heritability. Such findings add knowledge to the understanding of brain states at rest and their connection with human behavior, and how their interaction is shaped by genes and environmental exposure.