PT  - JOURNAL ARTICLE
AU  - Amitai Shenhav
AU  - Uma R. Karmarkar
TI  - Dissociable components of the reward circuit are involved in appraisal versus choice
AID  - 10.1101/172320
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 172320
4099  - http://biorxiv.org/content/early/2018/12/17/172320.short
4100  - http://biorxiv.org/content/early/2018/12/17/172320.full
AB  - People can evaluate a set of options as a whole, or they can approach those same options with the purpose of making a choice between them. A common network has been implicated across these two types of evaluations, including regions of ventromedial prefrontal cortex and the posterior midline. We test the hypothesis that sub-components of this reward circuit are differentially involved in triggering more automatic appraisal of one’s options (Dorsal Value Network) versus explicitly comparing between those options (Ventral Value Network). Participants undergoing fMRI were instructed to appraise how much they liked a set of products (Like) or to choose the product they most preferred (Choose). Activity in the Dorsal Value Network consistently tracked set liking, across both task-relevant (Like) and task-irrelevant (Choose) trials. In contrast, the Ventral Value Network was sensitive to evaluation condition (more active during Choose than Like trials). Within vmPFC, anatomically distinct regions were dissociated in their sensitivity to choice (ventrally, in medial OFC) versus appraisal (dorsally, in pregenual ACC). Dorsal regions additionally tracked decision certainty across both types of evaluation. These findings suggest that separable mechanisms drive decisions about how good one’s options are versus decisions about which option is best.