[1] Univ Bristol, Henry Wellcome Labs Intergrat Neurosci & Endocrin, Bristol, Avon, England
[2] Univ Bristol, Clin Res & Imaging Ctr, Bristol, Avon, England
[3] Univ Bristol, Sch Expt Psychol, Bristol, Avon, England
[4] Kings Coll London, Inst Psychiat Psychol & Neurosci, London, England