Fig. 2

SWM task performed during the fMRI scan. For the SWM task (top two), subjects had to remember the positions of the boxes in which an apple (target) was presented sequentially. After 2,000 ms of delay following the presentation of the target in the final box for a given trial, one of the boxes was highlighted, and the subjects pressed a button to indicate whether or not the target had appeared in this box. For the “memory load = 3” condition, the target was presented in three of the ten boxes, whereas for the “memory load = 5” condition, five boxes were used target locations. For the baseline task (bottom), the stimuli were presented sequentially in the predictable order (i.e. top-left, top-right, bottom-left, bottom-right). When the middle box was highlighted after the delay, subjects pressed the pre-specified button