1 Division Bernstein Center for Computational Neuroscience Berlin, Humboldt University Berlin, Philippstr. 13, Haus 2, Berlin, 10115, Germany. bc@bccn-berlin.de.
2 Department of Mathematics, Applied Mathematics, and Statistics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio, 44106, USA.
3 Departments of Psychology ad Biomedical Engineering, University of Arizona, 1503 E University Blvd, Tucson, AZ, 85721, USA.
4 Donders Institute, Faculty of Science, Radboud University, Heyendaalseweg 135, Nijmegen, AJ, 6525, Netherlands.