1. From Departments of Neurology (E.O., M.N., J.M., R.L., L.C., C.D., J.C., A.E.H.) and Physical Medicine and Rehabilitation (A.E.H.), Johns Hopkins Cognitive Science (A.E.H.), Johns Hopkins University School of Medicine, Baltimore, Md; Institute of Cognitive Neuroscience (J.C.), University College London, London, UK.