Figure 1.

Schematic representations of trials in two different WM tasks. (Upper) A sample trial for the item-recognition task. It includes the following events: (i) fixation point, (ii) four uppercase letters, (iii) blank delay interval, and (iv) a lowercase probe letter. The subject’s task was 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 was to decide whether each letter has the same name as the one that occurred two back in the sequence The durations for each trial event are shown.