Resting-State Brain Oscillations and Working Memory: The Role of EEG Coherence in Healthy Middle-Aged Individuals

This study investigated whether resting-state EEG coherence in the alpha, beta, and theta frequency bands predicts working memory performance in healthy middle-aged adults (N = 27, aged 49–64). Unlike prior research focusing on young adults or clinical populations, we examined the relationship between EEG coherence during eyes-open rest and performance on a range of working memory tasks, including updating (n-back task), switching, Stroop, and complex operation span (OSPAN task). Hierarchical regression analyses revealed that demographic variables (age, education) were generally not significant predictors, except for education in the updating task. Inclusion of EEG coherence significantly increased explained variance: alpha, beta, and theta coherence predicted performance in the updating task, while alpha and beta coherence predicted outcomes in the OSPAN task. Specifically, higher alpha coherence was associated with better performance, whereas lower theta and beta coherence predicted superior outcomes, suggesting enhanced neural flexibility and efficient cognitive resource allocation. EEG coherence did not significantly predict performance in the switching or Stroop tasks, likely because these tasks rely more on rapid reactive responses and local neural activity not captured by resting-state synchronization. These findings indicate that resting-state EEG coherence may serve as a frequency-specific neurophysiological marker of working memory in middle age. Future research should explore longitudinal changes and potential interventions, such as neurofeedback, to modulate coherence and enhance cognitive function.