Accessing semantic knowledge in dementia: evidence from a word definition task

Arlene J. Astell, Trevor A. Harley

    Research output: Contribution to journalArticle

    15 Citations (Scopus)

    Abstract

    We examine production of word definitions by people with probable Alzheimer's disease (pAD). In the first experiment, healthy young adults defined concrete, imageable nouns to provide a baseline of definitional ability. Analysis of these definitions identified the key defining features of each target item. In the second experiment, pAD participants and elderly controls produced definitions of the same items. In the third experiment, healthy young participants rated the adequacies of these definitions. Although as expected the pAD participants produced fewer good definitions than the other two groups, most of their responses still contained some relevant information. pAD definitions contained fewer pieces of information and the information they produced was more tangential to the primary concept than that provided by the young or elderly participants. We identify two possible explanations in semantic loss and metalinguistic impairment. We consider metalinguistic impairment to provide the more plausible explanation of pAD patients' definitional performance.
    Original languageEnglish
    Pages (from-to)312-326
    Number of pages15
    JournalBrain and Language
    Volume82
    Issue number3
    DOIs
    Publication statusPublished - 2002

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    dementia
    Semantics
    Dementia
    Alzheimer Disease
    semantics
    evidence
    experiment
    Aptitude
    Young Adult
    Healthy Volunteers
    young adult
    Alzheimer's Disease
    ability
    Experiment
    performance
    Group
    Impairment
    Metalinguistics

    Cite this

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    Accessing semantic knowledge in dementia: evidence from a word definition task. / Astell, Arlene J.; Harley, Trevor A.

    In: Brain and Language, Vol. 82, No. 3, 2002, p. 312-326.

    Research output: Contribution to journalArticle

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