Semantic knowledge was investigated in patients diagnosed with Dementia of the Alzheimer's Type (DAT) by means of an off-line probe question battery and an on-line measurement of semantic priming in a lexical decision task (LDT) that varied the stimulus onset asynchrony (SOA). The patients' performance on the detailed probe questions showed that their semantic deficit was confined primarily to animate concepts, characterized by visual descriptive features. In the primed LDT, demented patients demonstrated increased semantic priming compared to age-matched controls. A trend was also found indicating that for both normal controls and DAT subjects the priming magnitude decreased as the SOA increased. These results are interpreted in terms of a distributed representation of semantic knowledge that is impaired in demented patients.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.27483 |
| Date | January 1996 |
| Creators | Geva, Anat. |
| Contributors | Petitto, Laura Ann (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 (Department of Psychology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001558501, proquestno: MQ29858, Theses scanned by UMI/ProQuest. |
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