1. Department of Radiology, National Center Hospital, National Center of Neurology and Psychiatry, Tokyo 187-8551, Japan
2. Center for Evolutionary Cognitive Sciences, Graduate School of Art and Sciences, The University of Tokyo, Tokyo 153-8902, Japan
3. Department of Psychiatry, Jikei University School of Medicine, Tokyo 105-8461, Japan
4. Department of Neuropsychiatry, University of Tsukuba, Tsukuba 305-8576, Japan
5. Department of Drug Dependence Research, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo 187-8551, Japan
6. Department of Psychiatry, National Center Hospital, National Center of Neurology and Psychiatry, Tokyo 187-8551, Japan
7. Department of Radiological Sciences, School of Health Sciences, Fukushima Medical University, Fukushima 960-8516, Japan
8. Department of Radiology, Juntendo University School of Medicine, Tokyo 113-8421, Japan
9. Department of Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
10. Department of Biofunctional Imaging, Fukushima Medical University, Fukushima 960-1295, Japan
11. Drug Discovery and Cyclotron Research Center, Southern Tohoku Research Institute for Neuroscience, Fukushima 963-8052, Japan