1. Laboratory for Cognitive Neuroscience, Centre for Cognitive and Neural Systems, and Centre for Neuroscience Research, University of Edinburgh, 1 George Square, Edinburgh EH8 9JZ, Scotland, UK.
2. Division of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School and Faculty of Medicine, University of Tokyo, Faculty of Medicine Building 1, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
3. Centre for the Biology of Memory, Medical-Technical Research Centre, NO-7489 Trondheim, Norway.