1. Department of Psychology, University College London, Gower Street, London WC1E 6BT, UK; and Academic Department of Psychiatry, St Mary's Hospital Medical School, Praed Street, London W2 1PG, UK
2. Department of Clinical Psychology, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK
3. Department of Clinical Neurophysiology, The Maudsley Hospital, Denmark Hill, London SE5 8AZ, UK