Fig. 1.

Kid Monetary Incentive Delay (KIDMID) task trial structure and behavior.

(A) The Monetary Incentive Delay task for children (KIDMID) has 72 pseudo-randomized trials with 4 conditions: gain (+5 points), non-gain (+0), loss (-5), and non-loss (-0). In every trial, participants viewed an incentive cue (500 ms), anticipated the incentive (2000–2500 ms), responded to the target (160–350 ms, variable timing), fixated for a delay (900–1500 ms), and viewed the trial outcome (1500 ms). Trials lasted 6000 ms and were locked to three FMRI volume acquisitions (TR = 2000 ms).

(B) Participants hit more targets on gain versus non-gain trials (paired t(90) = 5.36, p < 0.001), and on loss versus non-loss trials (paired t(90) = 5.62, p < 0.001). Participants had faster reaction times for gain than non-gain trials (paired t(90)=-2.29, p = 0.02), and were faster in avoiding losses than avoiding non-losses (paired t(90)=-3.32, p < 0.01).