Schedule of Events | Symposia

Domain-Specific Neural Markers of Age-Related Episodic Memory Decline and Domain-General Markers of Compensation

Poster Session B - Sunday, March 30, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Maria Jieun Hwang¹ (mariahs@snu.ac.kr), Sang-Eon Park¹, Sang Ah Lee¹; ¹Seoul National University

In this study, we investigate the possibility that the observation of individual differences in age-related memory decline is driven, in part, by the domain-specificity of episodic memory components tested, as well as the existence of both dysfunctional and compensatory changes in the aging brain. We aimed to tease apart these factors by using an episodic memory task in which participants in the fMRI scanner were shown a sequence of scenes and subsequently tested on the objects (what), locations of objects (where), and temporal order (when) of the scenes. Results from healthy older (age 50-86; n=120) and younger adults (age 20-30; n=41) revealed a significant decline across aging in all episodic memory components (what: r=-0.67; where: r=-0.61; when: r=-0.70), with more individual variety in older adults. Among the episodic memory components, temporal memory was more severely impaired than the other components and associated with reduced hippocampal and parahippocampal activation in older adults. Interestingly, cortical activation, especially in the middle frontal gyrus, was higher in older adults and contributed to better performance overall in all three (what, where, and when) components. A hippocampal seed-based connectivity analysis further revealed that the prefrontal cortex was strongly coupled to the hippocampus during the retrieval in the older adult. Our findings indicate that dysfunction in the hippocampus and parahippocampus underlie a domain-specific spatiotemporal episodic memory decline, whereas prefrontal cortex upregulation functions as a domain-general compensatory mechanism, resulting in a complex model of individual differences in cognitive aging.

Topic Area: LONG-TERM MEMORY: Development & aging