Alexandra Nelson MD, PhD is the Richard and Shirley Cahill Endowed Chair in Parkinson’s Disease Research at the University of California, San Francisco. She is a movement disorders neurologist and systems neuroscientist, studying the role of the basal ganglia in action selection and movement disorders. Her laboratory uses electrophysiology & optical methods to investigate the mechanisms underlying abnormal motor and cognitive control in movement disorders, such as Parkinson’s Disease and dyskinesias.