The distinction between buying and "just browsing" illustrates how people can evaluate potential rewards with or without the intent to choose between them. A common network has been implicated across these two decision contexts, including regions of ventromedial prefrontal cortex and the posterior midline. However, recent work has begun to dissociate sub-components of this reward circuit, distinguishing a medial orbitofrontal (mOFC) Network from a rostral anterior cingulate (rACC) Network. These findings suggest that the rACC Network may play a relatively automatic role in appraising choice options whereas the mOFC Network may instead be more involved in choice comparison. We test this hypothesis by varying an individual's goals when approaching an option set. Participants undergoing fMRI were instructed to appraise how much they liked a set of products (Like) or to choose the product they most prefer (Choose). Set appraisal was driven by the average value of the items in a set, and correlated with activity in the rACC Network. Critically, this network tracked set liking when it was task-relevant (Like trials) and task-irrelevant (Choose trials). The mOFC Network was sensitive to evaluation condition, more active during Choose than Like trials. These regions dissociate, with mOFC selective for evaluation type but not appraisal, whereas the reverse was true for rACC. rACC additionally tracked how certain the participant was in both types of evaluations. These findings are consistent with the possibility that different circuits are involved in appraising the overall value of a set of options versus choosing which option is best.. CC-BY 4.0 International license peer-reviewed) is the author/funder. It is made available under a The copyright holder for this preprint (which was not . http://dx.doi.org/10.1101/172320 doi: bioRxiv preprint first posted online Dissociable mechanisms of appraisal versus choice 3
Significance statementPeople are capable of evaluating items to choose amongst them or to simply appraise ("browse") the set. Despite both tasks requiring an evaluation of one's options, choice and appraisal are associated with different phenomenological experiences. It has therefore been proposed that these processes draw on different but adjacent neural circuits, with an appraisal-related network triggering more automatic reactions to one's options and a choice-related network engaging in explicit comparison between them. We directly test this hypothesis, showing that these forms of evaluation engage dissociable components of a broader reward circuit. These findings suggest that decisions about how good one's options are (and possibly whether to approach them) are driven by different mechanisms than decisions about which option is best.