title: Word recognition in Alzheimer's disease: Effects of semantic degeneration.
abstract: Impairments of word recognition in Alzheimer's disease (AD) have been less widely investigated than impairments affecting word retrieval and production. In particular, we know little about what makes individual words easier or harder for patients with AD to recognize. We used a lexical selection task in which participants were shown sets of four items, each set consisting of one word and three non-words. The task was simply to point to the word on each trial. Forty patients with mild-to-moderate AD were significantly impaired on this task relative to matched controls who made very few errors. The number of patients with AD able to recognize each word correctly was predicted by the frequency, age of acquisition, and imageability of the words, but not by their length or number of orthographic neighbours. Patient Mini-Mental State Examination and phonological fluency scores also predicted the number of words recognized. We propose that progressive degradation of central semantic representations in AD differentially affects the ability to recognize low-imageability, low-frequency, late-acquired words, with the same factors affecting word recognition as affecting word retrieval.
authors.affiliation: University of Oviedo, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Cuetos
authors.affiliation: University of Oviedo, Spain.
authors.forename: Noemí
authors.initials: N
authors.lastname: Arce
authors.affiliation: Cabueñes Hospital, Gijón, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Martínez
authors.affiliation: University of York, UK.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Ellis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000000981:diagnostic imaging / Q000209:etiology*; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D021641:Recognition, Psychology / Q000502:physiology*; D012660:Semantics; D015898:Tomography Scanners, X-Ray Computed; D014706:Verbal Learning / Q000502:physiology; D014825:Vocabulary
keywords: 
  N
  ; Alzheimer's disease; age of acquisition; dementia; imageability; lexical decision; phonological fluency; semantic fluency; semantics; word frequency; word length; word recognition