Impaired Semantic Knowledge Underlies the Reduced Verbal Short-Term Storage Capacity in Alzheimer's Disease

Autor/inn/en	Peters, Frederic; Majerus, Steve; De Baerdemaeker, Julie; Salmon, Eric; Collette, Fabienne
Titel	Impaired Semantic Knowledge Underlies the Reduced Verbal Short-Term Storage Capacity in Alzheimer's Disease
Quelle	In: Neuropsychologia, 47 (2009) 14, S.3067-3073 (7 Seiten) PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0028-3932
DOI	10.1016/j.neuropsychologia.2009.07.002
Schlagwörter	Control Groups; Semantics; Alzheimers Disease; Word Lists; Diseases; Older Adults; Patients; Short Term Memory; Verbal Ability; Aging (Individuals); Phonology; Recall (Psychology); Task Analysis + Suchen Sie Ihr Suchwort? Semantik; Wortliste; Disease; Krankheit; Älterer Erwachsener; Patient; Kurzzeitgedächtnis; Mündliche Leistung; Aging; Altern; Fonologie; Abberufung; Aufgabenanalyse
Abstract	A decrease in verbal short-term memory (STM) capacity is consistently observed in patients with Alzheimer's disease (AD). Although this impairment has been mainly attributed to attentional deficits during encoding and maintenance, the progressive deterioration of semantic knowledge in early stages of AD may also be an important determinant of poor STM performance. The aim of this study was to examine the influence of semantic knowledge on verbal short-term memory storage capacity in normal aging and in AD by exploring the impact of word imageability on STM performance. Sixteen patients suffering from mild AD, 16 healthy elderly subjects and 16 young subjects performed an immediate serial recall task using word lists containing high or low imageability words. All participant groups recalled more high imageability words than low imageability words, but the effect of word imageability on verbal STM was greater in AD patients than in both the young and the elderly control groups. More precisely, AD patients showed a marked decrease in STM performance when presented with lists of low imageability words, whereas recall of high imageability words was relatively well preserved. Furthermore, AD patients displayed an abnormal proportion of phonological errors in the low imageability condition. Overall, these results indicate that the support of semantic knowledge on STM performance was impaired for lists of low imageability words in AD patients. More generally, these findings suggest that the deterioration of semantic knowledge is partly responsible for the poor verbal short-term storage capacity observed in AD. (Contains 2 figures and 3 tables.) (As Provided).
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Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2017/4/10