Geert J M van Boxtel1, John H Gruzelier2. 1. Department of Cognitive Neuropsychology, Tilburg University, P.O. Box 90153, 5000 LE, Tilburg, The Netherlands. Electronic address: G.J.M.vBoxtel@uvt.nl. 2. Department of Psychology, Goldsmiths, University of London, Lewisham Way, New Cross, SE14 6NW, London UK. Electronic address: J.Gruzelier@gold.ac.uk.