The Charles Bonnet syndrome is characterized by complex visual hallucinations in people without psychopathology or disturbance of normal consciousness. This thesis highlights the association of visual deficits with the syndrome, and proposes that it is analogous to the perception of phantom limbs; both conditions arise when normal sensory input to the brain is severely reduced. The five studies that comprise this thesis systematically gather information on the syndrome to answer three basic questions: how can the hallucinations be classified, what are the clinical implications for individuals who experience them, and what might cause the hallucinations. Study 1 examines 64 cases described in the literature. Demographic information on the hallucinators, properties of the hallucinations, initiating factors, as well as etiological mechanisms are reviewed. Study 2 examines the properties of the hallucinations in a sample of 60 subjects and reveals, by statistical analysis, a dimension of the hallucinatory experience that ranges from discrete, singular perceptual experiences to multiple changing experiences. Studies 3 and 4 examine the mental status of hallucinators score within the normal range on tests of anxiety, depression, and psychological symptomology and exhibit no evidence of gross cognitive impairment. A detailed analysis of results show that a small proportion of hallucinators score within the normal range on tests of anxiety, depression, and psychological symptomology and exhibit no evidence of gross cognitive impairment. A detailed analysis of results show that a small proportion of hallucinators endorse comparatively more symptom-oriented items than the remainder of hallucinators, as well as more items non-hallucinators (in Study 4). Finally, Study 5 examines the performance of two hallucinating groups as well as a group of visually impaired non-hallucinating on threshold estimation and signal detection tasks. The results of the combined studies indicate
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.40243 |
| Date | January 1995 |
| Creators | Schultz, Geoffrey Robert |
| Contributors | Melzack, Ronald (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 | Doctor of Philosophy (Department of Psychology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001492198, proquestno: NN12476, Theses scanned by UMI/ProQuest. |
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