1. Department of Electrical Engineering and Information Systems, School of Engineering, The University of Tokyo,7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
2. Institute for Cognitive Systems, Department of Electrical and Computer Engineering, Technical University of Munich, Karlstraße 45/II, 80333 München, Germany.
3. Neuromuscular Diagnostics, Department of Sport and Health Sciences, Technical University of Munich, Georg-Brauchle-Ring 60/62, 80992 München, Germany.
4. Institute for Advanced Study, Technical University of Munich, Lichtenbergstrasse 2a, 85748 Garching, Germany.