Fig. 1.

Diagram of the working memory task showing the event order and trial types. Subjects were instructed to encode the memoranda (3 faces) and had to actively maintain them in working memory during a delay period while looking at distractors. During the retrieve period subjects were required to press a response button to indicate whether the probe (single-face) was part of the memoranda. Three categories of trials were presented during the working memory delay period, defined by the type of distractors (i) combat-related scenes from Iraq or Afghanistan, (ii) non-combat scenes, or (iii) digitally scrambled images. Each trial contained two distractors from the same category that were presented, consecutively, for 3 s each.