Jonas Tesarz1, Andreas Gerhardt, Rolf-Detlef Treede, Wolfgang Eich. 1. Department of General Internal Medicine and Psychosomatics, Medical Hospital, University of Heidelberg, Im Neuenheimer Feld 410, Heidelberg D-69120, Germany Chair of Neurophysiology, Center for Biomedicine and Medical Technology Mannheim (CBTM), University of Heidelberg, Mannheim D-68167, Germany Department of General Internal Medicine and Psychosomatics, Medical Hospital, University of Heidelberg, Heidelberg D-69120, Germany.