1. Centre for Neuroscience and Trauma; Blizard Institute, Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine & Dentistry, Queen Mary University of London, 26 Ashfield Street; London E1 2AJ United Kingdom
2. Medical Acute Assessment Unit, Royal London Hospital, Barts Health NHS Trust, Whitechapel Road, Whitechapel; London E1 1BB United Kingdom
3. Research Department of Clinical, Educational and Health Psychology; University College London, Gower Street; London WC1E 6BT United Kingdom
4. Department of Neuroimaging; King's College London, Institute of Psychiatry, Psychology & Neuroscience; London SE5 8AF United Kingdom
5. Department of Physiology; Northwestern University, Feinberg School of Medicine; Chicago Illinois 60611
6. Department of Gastroenterology; University Hospitals Midlands NHS Trust, Stoke on Trent; Staffordshire ST4 6QG United Kingdom