Education moderates the effect of hippocampal volume on episodic memory decline

Poster Session C - Sunday, April 14, 2024, 5:00 – 7:00 pm EDT, Sheraton Hall ABC

Annalise LaPlume¹ (annaliselaplume@torontomu.ca), Samira Mellah², Natasha Rajah^1,3, Sylvie Belleville^2,4; ¹Toronto Metropolitan University, ²Institut Universitaire de Geriatrie de Montréal, ³McGill University, ⁴Université de Montréal

Episodic memory is the ability to encode, store, and retrieve information about past events. The hippocampus is critical for episodic memory. Volumetric hippocampal declines, and subsequently episodic memory declines, are a hallmark of advanced age and Alzheimer’s disease. However, the degree to which age or Alzheimer’s disease affects the association between hippocampal volume and episodic memory varies across people. Such individual differences may be explained by cognitive reserve, a property of the brain that allows for cognitive performance that is better than expected given the degree of brain changes due to aging or disease. In the current study, we test the cognitive reserve hypothesis by measuring whether education (a cognitive reserve proxy) protects episodic memory from expected decline due to hippocampal volume. We used an existing database of 62 older adults at risk of Alzheimer’s disease, from the Consortium for Early Identification of Alzheimer’s Disease-Quebec. Participants reported the years of education completed. They received anatomical 3D-T1-w structural MRIs. Hippocampal volume segmentation was done with FreeSurfer 5.3 standard pipeline steps. Participants completed a Face-Name episodic memory task at baseline, two years later, and four years later. Regression analyses using the R statistical software v.4.3.0 revealed education significantly moderated the effect of hippocampal volume on episodic memory decline, β=-1.97 (SE=0.93). A Johnson-Neyman analysis found that over 14 years of education was neuroprotective against hippocampal-related memory decline. Analyses did not reveal any sex differences. Findings support the cognitive reserve hypothesis that lifestyle factors can shield cognition from neurodegeneration due to life-course/brain disease-related changes.

Topic Area: LONG-TERM MEMORY: Episodic