1. N.M. Taylor, MB, BS, FRCA, Senior Registrar, Department of Anaesthesia, St. George's Hospital, Blackshaw Road, London SW17 0QT, G.M. Hall, MB, BS, PhD, FIBiol, FRCA, Professor, Department of Anaesthesia, St. George's Hospital Medical School, Cranmer Terrace, London SW17 0RE, P. Salmon, MSc, Dphil, Reader in Clinical Psychology. Department of Clinical Psychology, The University of Liverpool, Ground Floor, The Whelan Building, Liverpool L69 3BX.