1. Spinal Cord Injury Center Balgrist, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
2. Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
3. Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, United Kingdom.
4. Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
5. Department of Brain Repair and Rehabilitation, Institute of Neurology, University College London, London, United Kingdom.