[1] Univ Calif Los Angeles, David Geffen Sch Med, Semel Inst Neurosci & Human Behav, Los Angeles, CA 90025 USA
[2] Univ Calif Los Angeles, David Geffen Sch Med, Div Pulm Med, Exercise Physiol Res Lab, Los Angeles, CA 90025 USA
[3] Azusa Pacific Univ, Psychol Dept, Azusa, CA 91702 USA
[4] Vet Affairs Greater Los Angeles Healthcare Syst, Los Angeles, CA USA
[5] Univ Vermont, Vermont Ctr Behav & Hlth, Burlington, VT 05405 USA
[6] Western Univ, Victoria Hosp, London Hlth Sci Ctr, Schulich Sch Med & Dent,Dept Psychiat, 800 Commissioners Rd East, London, ON N6A 5W9, Canada