The present experiment was conducted to explore the time-course of lexical ambiguity resolution in normal control (NC) subjects and the nature of right hemisphere-damaged (RHD) and left hemisphere-damaged (LHD) patients' impairments in this process. NC, RHD and LHD subjects performed a cross-modal lexical decision task, in which they heard sentence contexts that were biased toward the dominant or subordinate meanings of ambiguous words occurring before the end of the sentence. Written target words related to the dominant or subordinate meaning of the ambiguous words were introduced either at the onset of the ambiguous word (immediate condition), or 1000 ms later (delayed condition). Results revealed that both dominant and subordinate meanings were primed in the immediate condition, irrespective of context type or group. In the delayed condition, only the contextually-appropriate dominant meanings were primed in normal control subjects, whereas both patient groups showed significant priming only for the contextually-inappropriate dominant meanings. Findings for the NC subjects are interpreted in support of a modular model of lexical ambiguity resolution, and more specifically of an exhaustive access view. Patients' results are discussed with reference to a delayed suppression mechanism of inappropriate meanings, which is thought to be involved in these patients' language comprehension deficits.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.32978 |
| Date | January 2001 |
| Creators | Barrette, Martine. |
| Contributors | Baum, S. R. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (School of Communication Sciences and Disorders.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001845451, proquestno: MQ75288, Theses scanned by UMI/ProQuest. |
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