1. Department of Clinical Neurophysiology; University Medical Center, University of Göttingen; 37075 Göttingen Germany
2. Leibniz Research Centre for Working Environment and Human Factors; 44139 Dortmund Germany
3. Department of Psychology; University of California; Berkeley CA 94720 USA
4. Department of Psychiatry and Psychotherapy; Klinikum der Universität München; 80336 München Germany
5. University Medical Hospital Bergmannsheil; 44789 Bochum Germany