Training-Induced Plasticity in Dynamic Functional Network States: Divergence and Occupancy Associations with Behavioral and Cognitive Measures in Healthy Young Adults

Understanding how lifestyle factors influence the dynamic organization of intrinsic brain networks in young adulthood is critical for identifying mechanisms that support cognitive health during a formative developmental period. In this study, we examined whether an 8-week physical activity and cognitive training intervention altered dynamic functional network connectivity (dFNC) patterns in undergraduate students and how these neural dynamics related to physical activity levels, sedentary behavior, and cognitive performance. Resting-state fMRI data were decomposed using a constrained ICA framework to extract 53 intrinsic connectivity networks, from which 10 dynamic connectivity states were identified and individualized via constrained dynamic double functional independent primitives (c-ddFIPs). We quantified state occupancy, convergence, and divergence to characterize network flexibility. Occupancy analyses showed modest but consistent associations linking greater physical activity with increased time in integrative, higher-order states (especially states 6 and 7) and reduced time in segregated or sensory-weighted states. Convergence and divergence analyses further revealed that physically active individuals demonstrated stronger differentiation between integrative and low-engagement states, whereas sedentary behavior corresponded to greater similarity among segregated configurations. Cognitive measures—particularly working memory—showed parallel relationships, aligning improved performance with more flexible and well-differentiated dynamic patterns. Together, these findings suggest that physical activity in young adults is associated with enhanced neural flexibility, characterized by greater engagement and differentiation of integrative connectivity states that support executive and other cognitive functions.