[1] Wellcome Ctr Integrat Neuroimaging, Nuffield Dept Clin Neurosci, Oxford, England
[2] Univ Oxford, Dept Pharmacol, Oxford, England
[3] Tech Univ Munich, Sch Med, Dept Neuroradiol, Munich, Germany
[4] Univ Oxford, Sleep & Circadian Neurosci Inst, Nuffield Dept Clin Neurosci, Oxford, England
[5] Univ Oxford, Dept Expt Psychol, Oxford, England