Brain and Behavioral Differences in Working Memory Updating Between Healthy Young and Older Adults

Poster Session B - Sunday, April 14, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Nathan Rose¹ (nrose1@nd.edu), Melanie Benitez¹, Chang-Mao Chao¹, Chenlingxi Xu¹, Zengbo Xie¹, Daniel Henrickson¹, Luke Bormann¹, Justine Fragetta¹; ¹University of Notre Dame

Deficits in working memory (WM) contribute to age-related cognitive declines, but the sources of these deficits remain unclear. The aim of the present study was to determine if there are neural (EEG/ERP decoding) and behavioral (n-back performance) indices of WM updating that differ between healthy young adults (YAs) and healthy older adults (OAs), and whether these indices can be used to predict age-related cognitive declines. More specifically, we aimed to test whether YAs and OAs retain information during a WM updating task via active or passive maintenance mechanisms during the delay period. To address these questions, two age groups [YA: N = 48, mean (SD) age = 19.9 (1.07); OA: N = 47, mean (SD) age = 70.68 (7.35)] performed a 1-back task during EEG recording. Preliminary decoding analyses of voltage ERPs, theta, alpha, beta, and low-gamma oscillations show that neither YAs nor OAs demonstrated sustained, active maintenance of attended WM representations throughout the duration of the delay period. Both groups showed passive retention, consistent with observations of “activity-silent” WM maintenance and the Synaptic Theory of WM. OAs showed slightly more sustained decoding accuracy during the delay period than YAs, and OAs' delay period decoding accuracy was negatively correlated with their fluid intelligence scores, suggesting that OAs who were experiencing greater cognitive decline engaged in more active WM maintenance, perhaps to support their performance, consistent with a compensatory recruitment account of age differences in WM.

Topic Area: EXECUTIVE PROCESSES: Working memory