The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on March 19, 2010). Thesis advisor: Dr. Steven A. Hackley. Includes bibliographical references.

Thesis (Ph. D.)--UCLA, 2009. / Vita. Description based on print version record. Includes bibliographical references.

Thesis (M. Phil.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 91-116).

Thesis (Ph. D.)--York University, 2000. Graduate Programme in Psychology. / Typescript. Includes bibliographical references (leaves 209-273). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNQ59157.

The work described in this dissertation aims to understand how postural instability (PI), a troubling symptom of advanced Parkinson's disease (PD) in humans, develops from the degeneration of nigrostriatal dopamine neurons characteristic of PD. The studies herein (1) outline the development of clinically relevant methods for evaluating PI in experimental rodents, (2) indicate that PI may not result directly from disruption of dopamine systems but may instead arise from non-dopaminergic changes that occur subsequent to dopamine depletion, and (3) search for specific evidence of plasticity or degeneration outside of the damaged nigrostriatal dopamine system that may be linked to the development of PI. It is hoped that this work will help lay the foundation for the development of novel prophylactic treatments aimed at preventing the progression of PD to advanced stages where treatment-resistant symptoms such as PI appear. / text

Not available / text

No description available.

published_or_final_version / Psychology / Master / Master of Philosophy

23 patients with idiopathic Parkinson's disease (PD) and 22 healthy control subjects participated in an experimental investigation of learned helplessness and illusion-of-control phenomena. Subjects were divided into depressed and non-depressed groups according to scores on the Beck Depression Inventory. Each completed four problems associated with an instrumental learning task in which they judged the degree of control their responses exerted over repeated green-light onset. Degree of contingency varied from 0% to 75% and subjects utilized both verbal and motor response modes. Subjects also estimated frequency of green light onsets for each problem. Contrary to expectation, PD subjects did not differ from relevant comparison groups in their contingency or frequency estimates. Tests of the prediction that depressed subjects' contingency ratings would be more accurate than non-depressives' approached significance (p < .064), although the pattern of mean differences was not consistent with an illusion-of-control interpretation.

No description available.