title: Comparison of semantic and episodic memory BOLD fMRI activation in predicting cognitive decline in older adults.
abstract: Previous studies suggest that task-activated functional magnetic resonance imaging (fMRI) can predict future cognitive decline among healthy older adults. The present fMRI study examined the relative sensitivity of semantic memory (SM) versus episodic memory (EM) activation tasks for predicting cognitive decline. Seventy-eight cognitively intact elders underwent neuropsychological testing at entry and after an 18-month interval, with participants classified as cognitively "Stable" or "Declining" based on ≥ 1.0 SD decline in performance. Baseline fMRI scanning involved SM (famous name discrimination) and EM (name recognition) tasks. SM and EM fMRI activation, along with Apolipoprotein E (APOE) ε4 status, served as predictors of cognitive outcome using a logistic regression analysis. Twenty-seven (34.6%) participants were classified as Declining and 51 (65.4%) as Stable. APOE ε4 status alone significantly predicted cognitive decline (R(2) = .106; C index = .642). Addition of SM activation significantly improved prediction accuracy (R(2) = .285; C index = .787), whereas the addition of EM did not (R(2) = .212; C index = .711). In combination with APOE status, SM task activation predicts future cognitive decline better than EM activation. These results have implications for use of fMRI in prevention clinical trials involving the identification of persons at-risk for age-associated memory loss and Alzheimer's disease.
authors.affiliation: Department of Psychology, Marquette University, Milwaukee, Wisconsin, USA.
authors.forename: Nathan
authors.initials: N
authors.lastname: Hantke
authors.forename: Kristy A
authors.initials: KA
authors.lastname: Nielson
authors.forename: John L
authors.initials: JL
authors.lastname: Woodard
authors.forename: Leslie M Guidotti
authors.initials: LM
authors.lastname: Breting
authors.forename: Alissa
authors.initials: A
authors.lastname: Butts
authors.forename: Michael
authors.initials: M
authors.lastname: Seidenberg
authors.forename: J
authors.initials: J
authors.lastname: Carson Smith
authors.forename: Sally
authors.initials: S
authors.lastname: Durgerian
authors.forename: Melissa
authors.initials: M
authors.lastname: Lancaster
authors.forename: Monica
authors.initials: M
authors.lastname: Matthews
authors.forename: Michael A
authors.initials: MA
authors.lastname: Sugarman
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Rao
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D053327:Apolipoprotein E4 / Q000235:genetics; D001921:Brain / Q000098:blood supply*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D061212:Memory, Episodic; D008609:Mental Status Schedule; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D011237:Predictive Value of Tests; D025341:Principal Component Analysis; D012660:Semantics
chemical_list: D053327:Apolipoprotein E4; D010100:Oxygen