Trial types used in each encoding condition prior to functional neuroimaging. (A) During GO trials, completing a response requirement on a response button in the presence of GO stimuli produced money. During NO-GO trials, withholding responding in the presence of NO-GO stimuli for 10 s terminated the stimulus and trial. In the Instructed encoding condition, subjects were told to memorize a set of stimuli. Subjects received equivalent amounts of exposure to stimuli in all three encoding conditions prior to neuroimaging. (B) During the active recognition memory task completed during neuroimaging, stimuli from each encoding condition were presented in a random order along with a baseline stimulus (asterisk). The recognition response involved making a categorical judgment regarding whether a stimulus was observed in the GO/NO-GO training condition (button #1), the instructed condition (button #2), or was NEW (button #3).