Fig 4. Control interval and frequency discrimination tasks.

(A) Short-Long reset task. The variable distractor in these trials was between 50–150 ms, and the target interval was 1 s. When a short unpredictable distractor preceded a long target interval there was no effect of whether the distractor was Fixed or Variable.

(B) Frequency task. A tone was presented in the absence of a distractor (open bars), or in the presence of a distractor tone presented at a fixed (red) or variable (blue) interval before the target tone. Conventions and color coding as in Figure 3.