Behavioral results.

<p>Top: Performance in the number comparison task. Left: In predictable blocks, RTs were significantly shorter in rewarded as compared to non-rewarded trials. Right: Similarly, accuracy was significantly lower in predictably not rewarded trials as compared to predictably rewarded trials. Bottom: Memory for items presented as cues and outcomes. Left: Memory was significantly better for cues which predicted a reward as compared to cues which were unpredictedly followed by a reward. Right: Items presented during processing of predictable outcomes were remembered better than those during unpredictable outcomes. Pred.  =  predictable, unpred.  =  unpredictable, rew.  =  reward, no rew.  =  no reward.</p

Subsequent memory effects and activation of memory-related regions during reward consumption.

<p>(a) Increased BOLD response in vmPFC for remembered contrasted to forgotten predicted outcomes. (b) Contrast of predicted vs. unpredicted outcomes masked (inclusively) by the contrast of forgotten vs. remembered outcomes. (c) Increased BOLD response for rewarding compared to non rewarding outcomes in predictable blocks in vmPFC (ci), nucleus accumbens (cii), and hippocampus (ciii and civ). (d) Interaction of reward and predictability for outcomes associated with activation of the posterior hippocampus. (e) Increased BOLD response in vmPFC for remembered contrasted to forgotten predicted rewards.</p

Activation of ventral striatum and ventromedial prefrontal cortex during unpredicted and predicted rewards and outcomes.

<p>(a) Increased BOLD response in vmPFC for predicted vs. unpredicted rewards. (b) Reverse contrast was associated with activation of the ventral striatum. (c) Increased BOLD response in vmPFC for predicted vs. unpredicted outcomes (rewards and no rewards). (d) Again, the reverse contrast activated the ventral striatum.</p

Overview of the experimental paradigm.

<p>(a) During scanning, subjects engaged in a number comparison task, which was followed by a monetary reward in some trials if correctly solved, while other trials were not rewarded. Prior to this task, a trial-unique cue from one of two categories was presented. Subjects had to infer from their experiences whether they were in an A-type block where the category of a cue predicted reward or not or in a B-type block, where cue category did not predict anything. During the outcome phase, a face surrounded by a green frame signaled a reward, while faces with red frames signaled no reward. After completion of 10 blocks and a break of 30 min, a surprise recognition memory task for all items presented as cues and during the outcome phase followed. (b) Schematic overview of trials within predictable and unpredictable blocks. Within predictable A-type blocks, the category of cue items reliably predicted the possibility of a reward after the number comparison task. In unpredictable B-type blocks, such a prediction was not possible, and rewards were thus received unpredictedly.</p

Reward consumption vs. anticipation.

<p>Increased BOLD response in vmPFC, bilateral ventral striatum, parahippocampal gyrus, and hippocampus during processing of predicted rewards vs. reward-predicting cues.</p

Overview of all significant clusters of activation in all relevant contrasts.

<p>Overview of all significant clusters of activation in all relevant contrasts.</p

Activation of ventral striatum and parahippocampal cortex during reward anticipation facilitates memory formation.

<p>(a) Increased BOLD response in the ventral striatum for reward-predicting as compared to no reward predicting cues. (b) Increased BOLD response in the right parahippocampal gyrus for remembered contrasted to forgotten predicting cues. (c) Enhanced BOLD activity in the right parahippocampal gyrus associated with the interaction of ‘precitability’ × ‘memory’.</p