Age-related changes of the time-varying features in the brain functional
connectivity and cognitive ageing
Abstract
Brain functional modular organization changes with age. Considering the
brain as a dynamic system, recent studies have suggested that
time-varying connectivity provides more information on brain functions.
However, the spontaneous reconfiguration of modular brain structures
over time during ageing remains poorly understood. In this study, we
investigated the age-related dynamic modular reconfiguration using
resting-state functional MRI data (615 participants, aged 18-88 years)
from Cam-CAN. We employed a graph-based modularity analysis to
investigate modular variability and the transition of nodes from one
module to another in modular brain networks across the adult lifespan.
Results showed that modular structure exhibits both linear and nonlinear
age-related trends. The modular variability is higher in early and late
adulthood, with higher modular variability in the association networks
and lower modular variability in the primary networks. In addition, the
whole brain transition matrix showed that the times of transition from
other networks to the dorsal attention network were the largest.
Furthermore, the modular structure was closely related to the number of
cognitive components and memory-related cognitive performance,
suggesting a potential contribution to flexibility cognitive function.
Our findings highlighted the notable dynamic characteristics in
large-scale brain networks across the adult lifespan, which enhanced our
understanding of the neural substrate in various cognition during
ageing. These findings also provided further evidence that
dedifferentiation and compensation are the outcomes of functional brain
interactions.