EEG Subsequent Memory Effects Capture Age-Related Cognitive Changes

Poster Session F - Tuesday, April 16, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Adam Broitman¹ (adamwb@sas.upenn.edu), Michael Kahana¹; ¹University of Pennsylvania

Prior studies of episodic memory have identified patterns of neural activity observed at encoding that predict later recall (subsequent memory effects). However, these studies have primarily recruited young adult participants, and it is unclear whether these patterns 1) similarly predict encoding success in older populations, or 2) reflect differences in memory performance across individuals. The present study investigated whether neural subsequent memory effects can capture age-related cognitive changes in free recall. We recorded scalp EEG in 156 young adults (aged 18-30) and 37 older adults (aged 60-85) as they memorized lists of words. During encoding, participants studied each word either freely (without encoding instructions) or while performing a secondary encoding task (judging the size or animacy of each item). Older adults exhibited distinct neural subsequent memory effects, characterized by reduced negativity in the theta, alpha, and gamma frequency bands, especially when encoding was coupled with a secondary task. Surprisingly, age-related differences in neural activity were most pronounced toward the end of the word list, where recall probability was similar between the two groups. The results suggest that neural differences between the age groups may capture compensatory changes in cognitive processing that mitigate age-related memory decline and allow older adults to successfully encode the final items in a list.

Topic Area: LONG-TERM MEMORY: Development & aging