1. E. A. Maguire, R. S. J. Frackowiak, C. D. Frith, Wellcome Department of Cognitive Neurology, Institute of Neurology, University College London, 12 Queen Square, London WC1N 3BG, UK.
2. N. Burgess, J. G. Donnett, J. O'Keefe, Department of Anatomy and Developmental Biology and Institute of Cognitive Neuroscience, University College London, Gower Street, London WC1E 6BT, UK.