Figure 1.

N-back verbal working memory-threat task. (A) Illustration of two-back task trials in the threat condition. Participants respond to every letter pressing either the S key for “same” (target) as the letter presented two letters back, or D for “different” (distractor) from the letter presented two letters back. In the example here, same is “z,” and different is J and G. The startle probe (air puff) and threat stimulus (shrieking scream) were presented during the intertrial intervals (ITIs). (B) Illustration of one run (eight blocks) with alternating threat and safe conditions of the working memory-threat task. Blocks were alternated between the threat and safe conditions. Three startle probes (air puff) were presented during each block and 0 to 2 shrieking screams were presented during the threat blocks.