Figure 1.

Reconstructed time courses from the left posterior cingulate, an area that was identified as active in this set-shifting task, although not typically seen on this kind of protocol. For intra-dimensional shifting, the PTSD group shows significantly greater activation in an early time window. For the extra-dimensional shifting, the between-groups difference is no longer significant due to the increased activation in this area in the military controls. Possibly, this increased activation reflects the increasing difficulty of the extra-dimensional shift, which is manifest as a stress-related increase in paralimbic regions for the controls. PTSD, posttraumatic stress disorder.