1. BioTechMed Center, Brain & Mind Electrophysiology Lab, Multimedia Systems Department, Faculty of Electronics, Telecommunication and Informatics, Gdansk University of Technology , 80-233 Gdansk , Poland
2. Department of Neurology, Mayo Clinic , Rochester, MN 55905 , USA
3. Department of Physiology and Biomedical Engineering, Mayo Clinic , Rochester, MN 55905 , USA
4. Department of Neuropsychology, Faculty of Psychology, Ruhr University Bochum , 44-780 Bochum , Germany