Paul Dieppe1, Chris Roe2, Sara L Warber3. 1. University of Exeter Medical School, Room 2.34, South Cloisters, St Luke's Campus, Exeter EX1 2LU, UK. Electronic address: p.dieppe@exeter.ac.uk. 2. Centre for the Study of Anomalous Psychological Processes, University of Northampton, Park Campus, Boughton Green Road, Northampton NN2 7AL, UK. 3. Department of Family Medicine, University of Michigan Integrative Medicine, Ann Arbor, MI 48104-1213, USA; European Centre for Environment and Human Health, University of Exeter Medical School, Truro, Cornwall TR1 3HD, UK.