Frequency-Resolved Cortical Functional Connectivity Across the Adult Lifespan.

The operation of the human brain relies on functional networks enabled by inter-areal oscillatory synchronization between neuronal populations. Although disruptions in this functional connectivity are associated with brain disorders, evidence on its healthy age-dependent variation and behavioral relevance remains limited. Utilizing magnetoencephalography (MEG) recordings from 576 adults aged 18-87 years, we investigated the evolution of resting-state functional connectivity (rs-FC) across the healthy adult lifespan. We observed age-related, frequency-specific changes in widespread cortical networks. Alpha-band (8-13 Hz) rs-FC decreased, while delta (1-4 Hz), theta (4-8 Hz), and gamma-band (40-90 Hz) rs-FC increased with age. Beta-band (13-30 Hz) rs-FC followed a non-linear trajectory, peaking in middle age. The global delta, theta, alpha, and beta-band patterns differed from concurrent changes in oscillatory power, underscoring their dissociable contributions. Notably, reduced beta-band rs-FC was associated with increased sensorimotor attenuation, indicating that changes in rs-FC are behaviorally relevant for sensorimotor function. These findings advance our understanding of healthy brain aging and highlight a link between resting-state brain activity and sensorimotor integration.