1. MRC Cyclotron Unit, Hammersmith Hospital, London, England
2. Departments of Psychiatry (Payne Whitney Clinic), New York Hospital-Cornell Medical Center, New York, New York, U.S.A.
3. Departments of Neurology and Neurosciences, New York Hospital-Cornell Medical Center, New York, New York, U.S.A.
4. Departments of Radiology, New York Hospital-Cornell Medical Center, New York, New York, U.S.A.