The association between brain oscillatory activity and immediate memory under different magnetoencephalography...

Oscillatory activity across various frequency bands in different brain regions has been associated with memory function, yet few population-based studies have explored its associations with immediate memory under different magnetoencephalography (MEG) paradigms in older adults. The population-based study included 90 participants. We utilized MEG with optically pumped magnetometers (OPM-MEG) to examine band-specific event-related desynchronization (ERD) across 94 brain regions under two task paradigms: animal and line paradigms. Immediate memory was assessed using the Auditory Verbal Learning Test (AVLT) and standardized to Z-score. Multivariable linear regression analysis was conducted to associate band-specific ERD with immediate memory Z-score. All p values were corrected for multiple comparisons using the false discovery rate (FDR) method. Increased beta-band ERD values (i.e., more positive values, reflecting weaker desynchronization) in the bilateral hippocampus were significantly associated with lower immediate memory Z-scores. (animal-left: R = -0.42, p < 0.001; animal-right: R = -0.50, p < 0.001; line-left: R = -0.30, p = 0.029; line-right: R = -0.37, p = 0.020). Significant associations between increased ERD and lower immediate memory Z-score were observed in the animal paradigm, particularly within the theta, alpha, and beta frequency bands in the bilateral hippocampus during the retrieval phase (all p < 0.05), whereas no significant associations were observed in the line paradigm after FDR correction. This study demonstrated that increased ERD, particularly in beta-band activity during memory retrieval, was associated with lower immediate memory function in the animal paradigm among older adults. The task-related ERD may serve as a potential biomarker for immediate memory function.