Visual Imagery and Perception in Posttraumatic Stress Disorder

BACKGROUND: Relative regional cerebral blood flow (rCBF) changes were measured in Vietnam combat veterans with and without posttraumatic stress disorder (PTSD) during exposure to combat-related stimuli. METHODS: Positron emission tomography was used to measure rCBF in 7 combat veterans with PTSD (PTSD group) and 7 healthy combat veterans (control group) who viewed and generated visual mental images of neutral, negative, and combat-related pictures. RESULTS: Unlike control subjects, subjects with PTSD had increased rCBF in ventral anterior cingulate gyrus and right amygdala when generating mental images of combat-related pictures; when viewing combat pictures, subjects with PTSD showed decreased rCBF in Broca's area. CONCLUSIONS: Results suggest that ventral anterior cingulate gyrus and right amygdala play a role in the response of combat veterans with PTSD to mental images of combat-related scenes. Reexperiencing phenomena of PTSD, which often involve emotional visual mental imagery, may be likewise associated with increased rCBF in these regions.