Debby Tsuang, MD, is leading a new study to find out if objective measures of sleep and movement patterns can effectively differentiate between people living with symptoms of probable Lewy Body Dementia and Alzheimer’s disease. In the study subjects will wear an actigraphy monitor to capture walking pace, gait, distance covered, calorie burned and heart rate as well as a Sleep Profiler, a self-applied device that records REM sleep muscle activity.