Adult lifespan trajectories of neuromagnetic signals and interrelations with cortical thickness

Oscillatory power and phase synchronization map neuronal dynamics and are commonly studied to describe the healthy or diseased brain. Yet, little is known about the course of these features from early adulthood into old age. Leveraging magnetoencephalography (MEG) resting-state data in a cross-sectional adult sample (n = 350), we probed lifespan differences (18-88 years) in connectivity and power and interaction effects with sex. Building upon recent attempts to link structure and function in the brain, we tested the spatial correspondence of age effects on cortical thickness and those on functional networks and a direct relationship at the level of the study sample. We found MEG frequency-specific patterns for lower- and higher-order brain regions and divergence between sexes in low frequencies. Connectivity and power exhibited distinct linear trajectories with age or turning points at midlife. Variability in cortical thickness with age corresponded to those in neuromagnetic activity, particularly in delta and beta oscillations, and showed coupling in either unimodal or transmodal regions depending on the frequency. Altogether, we provide a comprehensive overview of the topographic functional profile of adulthood that can form a basis for neurocognitive and clinical investigations. This study further sheds new light on how the brain's structural architecture relates to fast oscillatory activity in large-scale networks. ### Competing Interest Statement N.K. Focke has received speaker bureau and consultancy fees from Arvelle/Angelini, Bial, and Eisai, all unrelated to the present project. C. Stier and C. Braun have no relevant financial or non-financial interests to disclose.