Fig. 1.

Delay discounting task. (A) Delay discounting task trial; (B) Sensorimotor control trial. All trials were 11 sec in duration, with the initial fixation cross presented for two, four, or six sec, followed by two grey boxes paired with (A) the choice of an immediate or a delayed hypothetical monetary reward ($28 now or $34 in five days; a trial k of 0.041) or (B) the no choice option. Participants had the remainder of the 11-sec trial (nine, seven, or five sec) to indicate their preference by pressing a button on the side corresponding to their choice. The box under the choice turned green, indicating the response selection. A return of the fixation cross indicated the start of the next trial.