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