1. School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian, China
2. Department of Computer Science, University of Helsinki, Helsinki, Finland
3. Faculty of Information Technology, University of Jyvaskyla, Jyvaskyla, Finland
4. Centre for Interdisciplinary Brain Research, Department of Psychology, Faculty of Education and Psychology, University of Jyvaskyla, Jyvaskyla, Finland
5. Department of Biomedical Engineering, Lund University, Lund, Sweden