[1] VA San Diego Healthcare Syst, Psychol Serv 116B, La Jolla, CA 92161 USA
[2] Univ Calif San Diego, Sch Med, Dept Psychiat, La Jolla, CA 92093 USA
[3] Univ Calif San Diego, Sch Med, Dept Neurosci, La Jolla, CA 92093 USA
[4] Univ Calif San Diego, Sch Med, Dept Radiol, La Jolla, CA 92093 USA