EEG Biomarkers of Age-Related Memory Change

Abstract

The current study investigates whether electroencephalographic (EEG) activity reflects age-related memory changes during encoding. We recorded scalp EEG in 151 young adults (aged 18-30) and 37 older adults (aged 60-85) as they memorized lists of words. Subjects studied the word lists either under full attention or while performing a secondary task that required them to make semantic judgments about each word. Although the secondary task reduced recall among all subjects, differences in recall performance between the age groups were smaller when participants performed a secondary task at encoding. Older adults also exhibited distinct neural subsequent memory effects, characterized by less negativity in the alpha frequencies compared to young adults. Multivariate classifiers trained on neural features successfully predicted subsequent memory at the trial level in both young and older adults, and captured the differential effects of task demands on memory performance between young and older adults. The findings indicate that neural biomarkers of successful memory vary with both cognitive aging and task demands. Public significanceThe current study investigates the EEG spectral biomarkers of memory encoding in young and older adults, and identifies key features of neural activity associated with age-related memory change. We further find that age-related memory differences are smaller when participants perform a semantic judgment task during encoding, and that multivariate classifiers trained on the EEG data predict these effects.