1 Department of Computer Science, University of Cyprus, P.O. Box 20537, Nicosia 1678, Cyprus. Electronic address: cchrist@cs.ucy.ac.cy.
2 Department of Computational Neuroscience, Institute of Physiology, Czech Academy of Sciences, Videnska 1083, Prague 4, 14220, Czech Republic. Electronic address: kostal@biomed.cas.cz.
3 Faculty of Mathematics and Natural Sciences, Institute for Zoology, University of Cologne, Zülpicher Street 47b, 50674 Cologne, Germany. Electronic address: ansgar.bueschges@uni-koeln.de.