Neuropsychological studies investigating trauma-exposed and posttraumatic stress disorder (PTSD) subjects have generally underlined the significantly poorer performance of tasks that require attention, concentration, and verbal memory, and difficulty in regulating memories surrounding the traumatic event. A previous study (El Hage et al. Cognitive Neuropsychiatry, 2006) revealed that the trauma-exposed subjects scored higher on anxiety/depression scales, and lower on processing speed tests. Moreover, the study showed significant impairment in working memory partially mediated by speed processing, but not by anxiety or depression. These results suggest that processing speed makes a major contribution to trauma-related working memory decline, and needs to be investigated in further studies.The aim of the present study is to explore correlation between hippocampus volume, frontal dysfunction and cognitive slowing in trauma-exposed subjects, while examining brain activation during performance of working memory tasks using functional magnetic resonance.