1. Graduate School of Letters, Hokkaido University, N10 W7 Kita-ku, Sapporo, Japan 060-0810
2. Department of Psychology, Neuroscience and Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1
3. Interdisciplinary Institute of Management, London School of Economics and Political Science, Houghton Street, London, WC2A 2AE, UK