Date of Graduation

2003

Document Type

Thesis

Degree Type

MS

Committee Chair

Janine Mendola

Committee Chair

Janine Mendola

Abstract

Dopaminergic agonists such as L-dopa may improve visual sensitivity in subjects with abnormal vision, and possibly in subjects with normal vision. The aim of this study was to evaluate the effects of L-dopa on the contrast sensitivity function (CSF) psychophysically and physiologically in 14 healthy subjects. Subjects received either 250mg L-dopa/25mg Carbidopa or placebo. Functional magnetic resonance imaging (fMRI) and perceptual performance data was collected while subjects viewed stimuli over a range of spatial frequencies, at threshold (barely visible) contrast. The results suggest that contrast sensitivity did not significantly improve after L-dopa administration, and stimulus induced neural activation in visual cortex was not altered. Overall, given conditions of matched detectability, the cortical activation across spatial frequency was similar in global pattern including parietal and posterior and anterior temporal regions, a novel finding. This study can provide a baseline for comparing contrast perception in subjects with visual deficits in the future.

Share

COinS