Fig. 1
During the PASAT, single digit numbers were presented to each subject. They were asked to sum the current (nth) and second-to-last digit (nth−2): e.g. digits at timepoints C and A, D and B, E and C, and so on. Several correct answers in a row shortened the interval between digit presentations while long answers prolonged it (A). Subfigure B shows the timeline of the experiment. Figure adapted from Weller et al. [8], reprinted with permission