The association between brain oscillatory activity and immediate memory under different magnetoencephalography paradigms: A population-based study

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.