Official websites use. Share sensitive information only on official, secure websites. Healthy aging is typically accompanied by cognitive decline. Other work has shown that increasing age is associated with reduced segregation of large-scale brain functional networks. Here we tested the hypothesis that functional segregation SyS mediates this effect of middle-aged lifestyle on late-life cognition.
In all three tasks, we showed that SyS related to fluid intelligence even after adjusting for the nonlinear age effects. However, we found no evidence that SyS in late-life mediated the relationship between non-specific non-occupation midlife activities and either measure of cognition in late-life. Thus, the brain correlates of cognitive reserve arising from mid-life activities remain to be discovered. System segregation SyS is stable across different brain states.
Fluid intelligence, but not episodic memory, was robustly predicted by SyS. Late life SyS was not associated with midlife outside of work activities. Healthy aging is accompanied by decline in various cognitive functions Gorbach et al. Studies using resting-state fMRI have also found age-related differences in the functional organisation of large-scale networks.
Several such networks have been identified that show a modular organization, where regions from the same network tend to be functionally synchronised, but less synchronised with regions from other networks Bullmore and Bassett, , Bullmore and Sporns, , Bullmore and Sporns, , He and Evans, , Heuvel and Sporns, , Meunier et al. A modular functional network architecture may be important for optimal brain function and metabolic efficiency Bullmore and Sporns, , Van Den Heuvel and Sporns, , Wig, As such, age-related reductions in SyS may have detrimental effects on cognition Deery et al.
Indeed, a study by Chan et al. Although aging is on average associated with declining cognitive function, some people seem to be more resilient to this decline.
