International Graduate School Neuroscience, Ruhr-University Bochum, Bochum, Germany, Institute for Neural Computation, Ruhr-University Bochum, Bochum, Germany.|International Graduate School Neuroscience, Ruhr-University Bochum, Bochum, Germany, Mercator Research Group Structure of Memory, Department of Psychology, Ruhr-University Bochum, Bochum, Germany.|International Graduate School Neuroscience, Ruhr-University Bochum, Bochum, Germany, Institute for Neural Computation, Ruhr-University Bochum, Bochum, Germany.