Poster C89, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
Normal older adults’ performance on a famous faces task is related to gray matter thickness and amyloid-beta in ApoE4 carriers
Rachel Bell1, Stephanie L. Leal1, Taylor Mellinger1, Kaitlin Swinnerton1, William J. Jagust1; 1University of California, Berkeley
Many older adults experience difficulty retrieving names, and note a “tip-of-the-tongue” (TOT) phenomenon. To explore this, we added a time limit to the Northwestern University Famous Faces Task which requires participants to name famous people in a set of photographs. TOTs were counted when participants knew semantic information or a partial name, but did not get full naming points within 5 seconds. Cognitively normal older adults (n=73, MMSE=28.86 +/-1.19, age=56-94, education=16.74 +/-1.89) also completed neuropsychological testing, a 1.5T structural MRI, a PiB PET scan measuring amyloid-beta, and ApoE4 genotyping. Age positively correlated with TOT score (p=.033, r𝛕=.158), and score variability increased with age. To explore age-related variation, we regressed age on TOT score and divided subjects into one of two groups, either better or worse than expected for age. The group with fewer TOTs (for age) had greater mean gray matter thickness in bilateral parahippocampal gyrus (L:p=.004, R:p=.024), right inferior temporal lobe (p=.029), right temporal pole (p=.041), and right frontal operculum (p=.018) controlling for gender and education. TOT scores didn’t differ significantly by PiB status with the same covariates, but PiB positive ApoE4 carriers (n=10) had TOT residual scores correlated with amyloid-beta burden (p=.03, r𝛕=.50), while PiB positive ApoE4 non-carriers (n=12) did not. This study suggests face-naming ability is related to gray matter atrophy in regions associated with memory and face recognition and that amyloid-beta and ApoE4 status together are associated with a greater number of TOT responses.
Topic Area: LONG-TERM MEMORY: Development & aging