Identity-Specific Reward Representations in Orbitofrontal Cortex Are Modulated by Selective Devaluation

Abstract

Goal-directed behavior is sensitive to the current value of expected outcomes. This requires independent representations of specific rewards, which have been linked to orbitofrontal cortex (OFC) function. However, the mechanisms by which the human brain updates specific goals on the fly, and translates those updates into choices, have remained unknown. Here we implemented selective devaluation of appetizing food odors in combination with pattern-based neuroimaging and a decision-making task. We found that in a hungry state, participants chose to smell high-intensity versions of two value-matched food odor rewards. After eating a meal corresponding to one of the two odors, participants switched choices toward the low intensity of the sated odor but continued to choose the high intensity of the nonsated odor. This sensory-specific behavioral effect was mirrored by pattern-based changes in fMRI signal in lateral posterior OFC, where specific reward identity representations were altered after the meal for the sated food odor but retained for the nonsated counterpart. In addition, changes in functional connectivity between the OFC and general value coding in ventromedial prefrontal cortex (vmPFC) predicted individual differences in satiety-related choice behavior. These findings demonstrate how flexible representations of specific rewards in the OFC are updated by devaluation, and how functional connections to vmPFC reflect the current value of outcomes and guide goal-directed behavior.

Elucidating the underlying components of food valuation in the human orbitofrontal cortex

“…Furthermore, we found evidence for effective connectivity between the value-related medial OFC sub-region and the lateral OFC sub-regions representing each of the individual nutrient attributes. Recent human neuroimaging studies have demonstrated that medial OFC and adjacent regions of mPFC encodes value information independently of the category of goods as a “common currency” 6,8 , while lateral OFC encodes value in an identity-specific manner 8,21 and that identity-specific value representations are modulated by selective devaluation 35 . Our findings go beyond these previous studies in that we elucidate which constituent attributes underlie the construction of food value and how the constituent attributes are represented in the OFC.…”

Specialized Representations of Value in the Orbital and Ventrolateral Prefrontal Cortex: Desirability versus Availability of Outcomes

“…In line with this idea, medial PFC receives projections from both OFC and VLPFC (Carmichael and Price, 1996). In addition, fMRI studies in macaques and humans have found activations in medial PFC that are modulated not only by outcome contingency (Kaskan et al, 2016; Tanaka et al, 2008), delays in receiving an outcome (Kable and Glimcher, 2007) and the current biological value of outcomes (Howard and Kahnt, 2017), but also by the comparison between alternative outcomes (Boorman et al, 2009). …”

Orbitofrontal Cortex: A Neural Circuit for Economic Decisions

“…In addition to these considerations, it is worth noting that several imaging studies did in fact find value signals in the OFC (Arana et al, 2003; Chaudhry et al, 2009; Gottfried et al, 2003; Hare et al, 2008). These include in particular recent studies that focused on signals associated with individual goods or options (Howard et al, 2015; Howard and Kahnt, 2017; Klein-Flugge et al, 2013). Furthermore, a distinction recently drawn by San Galli et al (2016) seems potentially revealing.…”