Processing of lexical ambiguity in patients with traumatic brain injury.
Item
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Title
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Processing of lexical ambiguity in patients with traumatic brain injury.
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Identifier
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AAI9630449
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identifier
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9630449
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Creator
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Chobor, Karen Lynn.
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Contributor
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Adviser: Loraine K. Obler
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Date
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1996
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Language
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English
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Publisher
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City University of New York.
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Subject
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Language, Linguistics | Health Sciences, Speech Pathology | Psychology, Psychobiology | Biology, Neuroscience
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Abstract
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Most words possess some indeterminacy in their meanings (Burgess and Simpson, 1988), so ambiguity may be a characteristic that pervades natural language processing (Simpson, Burgess and Peterson, 1987; Swinney, 1982). In English, it has been estimated that over 50% of words have more than one meaning (Ziff, 1967).;The majority of lexical ambiguity studies in normals have been interpreted according to a multiple, or exhaustive, access model, which refers to the access of all meanings of an ambiguous word upon presentation of that word. In studies using brain-injured subjects, interpretation has centered on localizing the neurological substrate for such linguistic processing rather than determining the necessary cognitive mechanisms. Right hemisphere function has often been determined as necessary for successful processing of lexical ambiguity.;A comprehensive review of research in lexical ambiguity does not reveal such clear-cut interpretations, however. There are, in fact, a substantial number of studies using normals that speak to access according to context or frequency effects--referred to as "selective access", rather than "multiple access". Further, results of studies using brain-injured subjects reveal much evidence suggesting cognitive difficulties traditionally assigned to the frontal lobes as responsible for the handling of multiple meanings.;The goal of this study was to determine the type of cognitive functions required for the successful interpretation of lexical ambiguity, and this was carried out using a lexical decision (reaction time) task and a matching task, presented to brain-injured and normal subjects. Three categories of ambiguous words were used: homonymy, polysemy, and metaphor. The most striking finding on the reaction time task was that patients evidenced significantly slower reaction times on metaphor as compared to the normals.;On the matching task, patients achieved accuracy rates which were comparable to those of the normals, a finding that suggests relative intactness of the semantic representations of these words despite a retrieval deficit.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
