1. Department of Neurosurgery, San Francisco Veterans Affair Medical Center, San Francisco, California, USA
2. Centre for Cognitive and Neural Systems, University of Edinburgh, Edinburgh, UK
3. Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
4. Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK