Aperiodic component of EEG power spectrum and cognitive performance in aging: the role of education

Abstract

Aging is associated with changes in the oscillatory (periodic) brain activity in the alpha band (8-12 Hz), as measured with resting-state EEG (rsEEG), and it is characterized by significantly lower alpha frequency and power. Aging can influence the aperiodic component of the power spectrum: at a higher age, the slope flattens, and it may show a significant relationship with cognitive performance. However, it is unclear whether education, a cognitive reserve proxy known for its modulatory role on cognition, may influences such relationship. N=179 healthy participants from the LEMON dataset (Babayan et al., 2019) were classified into three groups based on age and education: young adults (N=123) 20-35 years old with high education, older adults 60-77 years old with high (N=24) and low (N=32) education. Eyes-closed rsEEG power spectrum was decomposed at the occipital level with specparam method. Individual Alpha Peak Frequency, exponent, and offset were analyzed in their relationship with cognitive abilities. Results show lower IAPF, exponent, and offset in older as compared to younger adults. Furthermore, visual attention and working memory were differently predicted by the aperiodic rsEEG component depending on educational levels: in older adults with higher education, increasing exponent predicted slower processing speed and less working memory capacity, with an opposite trend in those with lower education.Although further investigations are necessary, this study shows a potential modulatory role of education and other cognitive reserve proxies in the relationship between aperiodic rsEEG and cognition in aging.