The Value of Success: Acquiring Gains, Avoiding Losses, and Simply Being Successful

A large network of spatially contiguous, yet anatomically distinct regions in medial frontal cortex is involved in reward processing. Although it is clear these regions play a role in critical aspects of reward-related learning and decision-making, the individual contributions of each component remains unclear. We explored dissociations in reward processing throughout several key regions in the reward system and aimed to clarify the nature of previously observed outcome-related activity in a portion of anterior medial orbitofrontal cortex (mOFC). Specifically, we tested whether activity in anterior mOFC was related to processing successful actions, such that this region would respond similarly to rewards with and without tangible benefits, or whether this region instead encoded only quantifiable outcome values (e.g., money). Participants performed a task where they encountered monetary gains and losses (and non-gains and non-losses) during fMRI scanning. Critically, in addition to the outcomes with monetary consequences, the task included trials that provided outcomes without tangible benefits (participants were simply told that they were correct or incorrect). We found that anterior mOFC responded to all successful outcomes regardless of whether they carried tangible benefits (monetary gains and non-losses) or not (controls). These results support the hypothesis that anterior mOFC processes rewards in terms of a common currency and is capable of providing reward-based signals for everything we value, whether it be primary or secondary rewards or simply a successful experience without objectively quantifiable benefits

Outcome-related neural activations during the reward task in fMRI.

<p>A main effect of outcome was observed in anterior mOFC, such that this region responded to all successful outcomes regardless of stimulus type (A). A conjunction of successful gains, losses, and controls showed common success-related activity in a specific portion of anterior mOFC (B). The y-axis reflects parameter estimates (beta weights), and black bars represent standard errors.</p

An interaction of stimulus and outcome was observed in two regions.

<p>Pregenual ACC specifically differentiated the reception of monetary gains (A), whereas NAcc differentiated only monetary successes, gains and non-losses, from failures (B). The y-axis reflects parameter estimates (beta weights), and black bars represent standard errors.</p

Summary of neural activations observed for each F-test performed.

<p>All activations meet the criteria of p<.001 and a cluster size of at least 18 contiguous voxels.</p

Pilot study results of emotion ratings during the reward task.

<p>Participants gave ratings of each of 4 emotions on a 1–5 scale for the last outcome they had experienced. Ratings occurred randomly every 4–8 trials and were presented in a random order for each type of emotion. Ratings of positive emotions joy/excitement and calm/relief by stimulus type and outcome (A). Ratings of negative emotions agitation/frustration and dejection/disappointment by stimulus type and outcome (B). Black bars represent standard errors.</p

Example trial of the reward task.

<p>Stimuli were presented randomly for 1000ms. During this time, participants made a response by pressing a button corresponding to each stimulus type. A legend of the response options always appeared at the bottom of the screen. This was followed by 3000ms of feedback, which showed the outcome for each trial. Trials were separated by a fixation cross of variable length.</p