title: Failure of repetition suppression and memory encoding in aging and Alzheimer's disease.
abstract: The suppression of neural activity in the medial temporal lobe (MTL) has been suggested as a marker of successful recognition of familiarity in healthy subjects, but to be impaired in patients with Alzheimer's disease (AD). In this study, we investigated whether the ability to suppress MTL activity during repeated exposure to face-name pairs was related to the ability to successfully encode novel associations in 90 individuals ranging from healthy young and older subjects to mildly impaired elderly and AD patients. Activity in the anterior MTL during Repeated stimuli was inversely related to performance in post-scan associative recognition for the Novel face-name pairs. In a subset (n=60) of subjects undergoing more detailed neuropsychological testing, greater MTL Repeated activity was correlated with worse word-list delayed recall performance. Failure of response suppression to familiar information may be a sensitive marker of MTL dysfunction and memory impairment in aging and prodromal AD.
authors.affiliation: Unit of Neurology, Institute of Clinical Medicine, University of Eastern Finland, POB 1627, 70211, Finland, Finland. Maija.Pihlajamaki@uef.fi
authors.forename: Maija
authors.initials: M
authors.lastname: Pihlajamäki
authors.forename: Kelly
authors.initials: K
authors.lastname: O'Keefe
authors.forename: Jackie
authors.initials: J
authors.lastname: O'Brien
authors.forename: Deborah
authors.initials: D
authors.lastname: Blacker
authors.forename: Reisa A
authors.initials: RA
authors.lastname: Sperling
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000523:psychology*; D000544:Alzheimer Disease / Q000523:psychology*; D001244:Association; D003071:Cognition / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D021641:Recognition, Psychology / Q000502:physiology; D013702:Temporal Lobe / Q000502:physiology; D055815:Young Adult