1. Functional Magnetic Resonance Imaging of the Brain Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX39DU, UK.
2. Pfizer Ltd., Cambridge CB21 6GS, UK.
3. Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff CF10 3AT, UK.
4. Department of Neuroimaging, Institute of Psychiatry, King’s College, London SE58AF, UK.
5. Department of Anesthesiology, University of Michigan, Ann Arbor, MI 48105, USA.
6. Oxford University Centre for Human Brain Activity, Department of Psychiatry, University of Oxford, Oxford OX3 7JX, UK.