1. Emotion and Pain Laboratory, San Francisco Veterans Affairs Health Care Center, San Francisco, CA, United States
2. Department of Psychiatry, University of California San Francisco, San Francisco, CA, United States
3. Center for Imaging of Neurodegenerative Diseases, San Francisco Veterans Affairs Health Care Center, San Francisco, CA, United States
4. Department of Neurology, University of California San Francisco, San Francisco, CA, United States
5. San Diego Veterans Affairs Health Care Center, San Diego, CA, United States
6. Department of Psychiatry, University of California San Diego, San Diego, CA, United States