Cognitive Intra-Individual Variability is Differentially Associated with Long-term Memory across APOE Allele Status Groups

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

Taylor Shackelford¹, Ivan Campbell¹, Vasilios Ikonomou¹; ¹University of South Alabama

APOE allele status is implicated in cognitive decline in Alzheimer’s disease (AD), with the E4 allele conferring the most risk, followed by E3, then E2. To further investigate the role of APOE genotypes, the current study examines how individual performance variability, measured by cognitive intra-individual variability (IIV), correlates to long-term memory (LTM) in each allele group. Using AD and non-clinical participants from the National Alzheimer’s Coordinating Center Uniform Data Set, we examined this relationship across 6 APOE allele status groups: 1 (E3, E3), 2 ( E3, E4), 3 (E3, E2), 4 (E4, E4), 5 (E4, E2), and 6 (E2, E2). IIV obtained using the coefficient of variation calculation on performance across different neuropsychological measures was correlated to LTM for each allele group. Comparisons of group correlations were made using Fisher’s R-to-Z calculation. Significant associations were seen between IIV and LTM for all APOE allele status groups: 1 (r =-.149, p <.001), 2 (r =-.267, p =.001), 3 (r =-.427, p <.001), 4 (r =-.468, p <.001), 5 (r =-.625, p <.001), 6 (r =-.563, p <.001). Significant group differences included: 1 vs 2 (z=12.66, p <.001), 1 vs. 3 (z=22.71, p <.001), 4 vs. 2 (z=-13.73, p <.001), 4 vs 5 (z=8.23, p <.001), and 6 vs. 3 (z=-3.25, p=.001). However, 5 vs. 6 was not significant (z=-1.63, p=.10). These results suggest a genotypic effect on this relationship in AD and non-clinical populations.

Topic Area: LONG-TERM MEMORY: Development & aging