Parkinson's Disease Study The University of Vermont College of Medicine Fletcher Allen Health Care - Clinical Research Center in Burlington, Vermont is calling for participants in a study on: "The effects of acute and subchronic nicotine on attentional functioning in Alzheimer's and Parkinson' Disease." This study will test whether varying dosages of intravenous nicotine, followed by nicotine administered by skin patch for two weeks, can improve attentional learning and motor impairmants in Alzheimer's and Parkinson's disease patients. This short-term study aims to develop better treatments for patients with these disease. Principal Investigator: Paul Newhouse, M.D. Interested Parties should contact: Christina Conrath, MSW (802)656-4560 NOTE: Participants of the study who live a long distance from Burlington, Vermont will be provided lodging during the impatient phase of the study at the Clinical Research Center.