Mark Hallett, MD is Chief of the Human Motor Control Section, Medical Neurology Branch, NINDS, NIH, Bethesda, MD, USA. Anthony E. Lang, MD, FRCPC is Professor and Director of the Division of Neurology and Jack Clark Chair for Parkinson's Disease Research, University of Toronto, and Director of the Movement Disorders Center, Toronto Western Hospital, ON, Canada. Joseph Jankovic, MD is ... Read moreProfessor of Neurology, Distinguished Chair in Movement Disorders and Director of the Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Department of Neurology, Houston, TX, USA. Stanley Fahn, MD is H. Houston Merritt Professor of Neurology and Director of the Center for Parkinson's Disease and Other Movement Disorders, Columbia University, New York, NY, USA. Peter Halligan PhD, DSc, FBPsS, FPSI, FMedSci is Professor and Dean of Strategic Futures and Interdisciplinary Studies, Department of Psychology, University of Cardiff, UK. Valerie Voon, MD is a Clinical Research Associate in the Behavioral and Clinical Neuroscience Institute, Department of Psychiatry, University of Cambridge, UK. C. Robert Cloninger, MD is Wallace Renard Professor of Psychiatry and Director of the Center for Psychobiology of Personality, Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA. Show Less