Electrophysiological analysis of context effects in Alzheimer's disease.
Event-related potentials elicited by semantically associated and unassociated word pairs embedded in congruous and semantically anomalous spoken sentences were recorded from patients with Alzheimer's disease (AD) and healthy older and young controls as a means of examining the nature, time course, and relation between word and sentence context effects. All groups demonstrated lexical priming in nonsensical sentences, but it was earlier in the young (200-600 ms) than in the older controls (600-800 ms), and even later in the probable AD patients (800-1,000 ms). Moreover, processing in both the elderly and AD groups benefited disproportionately from a meaningful sentence context. The results do not accord well with either a strictly structural or a strictly functional account of the semantic impairments in AD.
Schwartz
Tanya J
TJ
Department of Psychology, Rehabilitation Hospital of the Pacific, Honolulu, Hawaii 96817, USA. tanyaschwartz@hawaii.rr.com
Federmeier
Kara D
KD
Van Petten
Cyma
C
Salmon
David P
DP
Kutas
Marta
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D000465:Algorithms; D000544:Alzheimer Disease / Q000503:physiopathology*; D001299:Audiometry; D001921:Brain / Q000502:physiology; D004594:Electrophysiology; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011932:Reading