Figure 1.

Schematic representations of trials in two different WM tasks. (Upper) A sample trial for the item-recognition task. It includes the following: (i) a fixation point, (ii) four uppercase letters, (iii) a blank delay interval, and (iv) a lowercase probe letter. The subject’s task is to decide whether the probe names one of the four target letters. (Lower) A sample trial for the 2-back task. Each letter is followed by a blank delay interval. The subject’s task is to decide whether each letter has the same name as the one that occurred two back in the sequence. The durations for all trial events are shown. Adapted from Smith et al. (38).