Education shapes the link between EEG aperiodic components and cognitive aging

Healthy aging brings widespread shifts in aperiodic (non-oscillatory) electroencephalographic (EEG) components, which may underlie physiological changes in cognitive performance. Education, a known protective factor against age-related decline in cognitive performance, has been largely overlooked in studies linking aperiodic EEG components to cognition. This study addresses this gap, hypothesizing that education moderates the interplay between age, aperiodic components, and cognitive performance, as measured by Mini-Mental State Examination (MMSE) scores. We reanalyzed an open-source EEG dataset of 714 healthy individuals aged 18-91 years using Generalized Additive Mixed Models. Aperiodic components (exponent and offset) declined with age, but higher education levels mitigated these declines. Notably, the aperiodic components interacted with age and education in predicting MMSE performance in a widespread way across the cortex. Among older adults, the relationship between the aperiodic components and cognitive performance diverged by education: those with lower education showed worse cognitive outcomes with lower exponents and offsets, whereas higher-educated individuals after 60 years showed a reverse pattern, with lower exponents and offsets predicting better MMSE performance. Our findings suggest that the link between aperiodic components and cognitive aging is not straightforward but depends on moderating factors such as education. These results underscore the importance of accounting for individual differences, like educational background, when exploring age-related changes in EEG aperiodic components and cognition.