1 From the Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital, and Harvard Medical School, Boston (L.R.H., S.S.C.); and the School of Engineering and Carney Institute for Brain Science, Brown University, and the Department of Veterans Affairs Rehabilitation Research and Development Service Center for Neurorestoration and Neurotechnology - both in Providence, RI (L.R.H.).