Abstract/Summary

Correlations in activity across disparate brain regions during rest reveal functional networks in the brain. Although previous studies largely agree that there is an age-related decline in the “default mode network,” how age affects other resting-state networks, such as motion-related networks, is still controversial. Here we used a dual regression approach to investigate age-related alterations in resting-state networks. The results revealed age-related disruptions in functional connectivity in all five identified cognitive networks, namely the default mode network, cognitive-auditory, cognitive-speech (or speech-related somatosensory) and right and left fronto-parietal networks, whereas such age effects were not observed in the three identified emotion networks. In addition, we observed age-related decline in functional connectivity in three visual and three motor/visuospatial networks. Older adults showed greater functional connectivity in regions outside four out of the five identified cognitive networks, consistent with the dedifferentiation effect previously observed in task-based fMRI studies. Both reduced within-network connectivity and increased out-of-network connectivity were correlated with poor cognitive performance, providing potential biomarkers for cognitive aging.