1. Clinical and Cognitive Neurosciences, Department of Neurology, Medical Faculty, RWTH Aachen University, Aachen, Germany
2. Department of Neurology, Medical Faculty, RWTH Aachen University, Aachen, Germany
3. St. Mauritius Rehabilitation Centre, Meerbusch, Germany, and
4. Division of Neuroscience and Experimental Psychology, School of Biological Sciences, University of Manchester, Manchester, UK