Cognitive Changes in Presymptomatic Parkinson's Disease
Abstract
Many of the neuropsychological changes reported with PD are not typically seen early in the disease. Therefore, there is a need to develop new cognitive tests of PD that precede the motor symptoms, are easy to administer and are valid early predictors. Moreover, it is important to understand the effect of the dopaminergic system on the cerebral cortex. One possible action of dopamine on the cerebral cortex is that of influencing activation within semantic networks. Thus, the goal of this project has been to study the semantic organization of verbal information in PD patients and matched controls, and determine the influence of dopamine on these cognitive processes. Data collected in our healthy subjects on the research task confirm our expectations that semantic processing can occur along a continuous gradient. Our preliminary data indicate that, when taking prescribed dopaminergic medication, our PD subjects demonstrate semantic processing that is similar to that of our control subjects. However, after an approximately 12-hour medication abstinence period, our PD subjects rated all semantically-associated stimuli as less similar than did controls. These results tentatively indicate that, as hypothesized, dopamine is involved in the mediation of neural activity (i.e., signal to noise ratio) within the semantic net.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2004
- Accession Number
- ADA433853
Entities
People
- Kenneth M. Heilman
Organizations
- University of Florida