Several behavioral studies have shown that memory is often enhanced for emotional stimuli in normals. Compared to normals, patients with Post-Traumatic Stress Disorder (PTSD) exhibit selectively enhanced recall for trauma-related material. but show deficits in recall of neutral stimuli. This suggests a functional abnormality of the emotional memory system in PTSD. Previous neuroimaging and neurobioligical studies have suggested that the amygdala, hippocampus, posterior cingulate, retrosplenial cortex, and prefrontal cortex are involved in the acquisition and retrieval of emotional episodic memory. This study uses fMRI to investigate neurofunctional differences between patients with PTSD and controls during the presentation of emotional and neutral stimuli. Subsequent recall and recognition of the stimuli will describe individual and group differences in memory performance. We hypothesize that PTSD subjects, compared to controls, will show increased amygdala and posterior cingulate cortex activation in response to threatening stimuli, but decreased hippocampus activation in response to neutral stimuli. Also, performance on the recall task will be related to the degree of activation in the amygdala and hippocampus. These studies will contribute to the understanding of how the brain enhances memory of emotional stimuli and how this memory for emotional and neutral stimuli may be altered in PTSD. These data will provide the foundation for a systematic program of clinical neuroscience research in PTSD.
