1. Dept. of Pure Mathematics and Mathematical Statistics, University of Cambridge, U.K
2. Univ Rennes, CNRS, IRMAR UMR 6625, France
3. AGH University of Krakow, Dept. of Applied Mathematics, al. Mickiewicza 30, 30-059, Krakow, Poland
4. Institut de Mathématiques de Marseille, Aix-Marseille University, France
5. Dept. of Psychology, University of Cambridge, U.K
6. Dept. of Psychology, University of Sussex, U.K