1. Department of Psychology, University of New Hampshire, Durham, NH, USA
2. Faculty of Psychology, School of Health Sciences, University of Iceland, Reykjavik, Iceland
3. ot1031@unh.edu
4. Laboratory of Psychophysics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
5. david.pascucci@epfl.ch
6. ak@hi.is