Methods: We assessed fMRI during a face-name association learning task in 26 healthy cognitively normal elderly participants. Using beta-series correlation analysis, we computed task-related LFC-connectivity to key memory networks including the default-mode network (DMN) and dorsal attention network (DAN). Network efficiency within the DMN and DAN was estimated by the graph theoretical small-worldness statistic. We applied linear regression analyses in
order to test the association between LFC-connectivity to the DMN/DAN and small-worldness of these networks. Mediation analysis was applied to test LFC-connectivity to the DMN and DAN as a mediator of the association between education and higher DMN and DAN smallworldness. Lastly, we tested network small-worldness as a predictor of memory performance.
Results: We found that higher LFC-connectivity to the DMN and DAN during successful memory encoding and recognition was associated with higher small-worldness of those networks. Higher task-related LFC-connectivity mediated the association between education and higher small-worldness in the DMN and DAN. Further, higher small-worldness of these networks predicted better performance in the memory task.
Conclusions: The current results suggest that higher education-related LFC-connectivity to key memory networks during a memory task is associated with higher network efficiency and thus enhanced reserve of memory abilities in aging.
- Cognitive reserve
- memory task-fMRI
- Fronto-parietal control network