Reward valuation in social contexts is made relatively in reference to others; socially relative reward valuation triggers various ‘other-regarding’ emotions

Socially relative reward valuation in the primate brain. Masaki Isoda. Current Opinion in Neurobiology, Volume 68, June 2021, Pages 15-22. https://doi.org/10.1016/j.conb.2020.11.008

Rolf Degen's take: https://twitter.com/DegenRolf/status/1336322948244762624

Highlights

• Reward valuation in social contexts is made relatively in reference to others.

• Socially relative reward valuation triggers various ‘other-regarding’ emotions.

• Socially relative reward valuation is mediated by social and reward neural networks.

• Medial prefrontal cortex and dopamine-related subcortical areas are mainly involved.

• Shared neural networks mediate this valuation in humans and nonhuman primates.

Abstract: Reward valuation in social contexts is by nature relative rather than absolute; it is made in reference to others. This socially relative reward valuation is based on our propensity to conduct comparisons and competitions between self and other. Exploring its neural substrate has been an active area of research in human neuroimaging. More recently, electrophysiological investigation of the macaque brain has enabled us to understand neural mechanisms underlying this valuation process at single-neuron and network levels. Here I show that shared neural networks centered at the medial prefrontal cortex and dopamine-related subcortical regions are involved in this process in humans and nonhuman primates. Thus, socially relative reward valuation is mediated by cortico-subcortically coordinated activity linking social and reward brain networks.

Conclusion

In social contexts, valuation of one's own reward is often made in reference to others’ rewards. This form of reward valuation readily invokes complex other-regarding emotions depending on the context at hand, ranging from those that can hinder interpersonal relations, such as envy and schadenfreude, to those that can promote productive social exchanges, such as empathy, reciprocity, and vicarious happiness. Although socially relative reward valuation is mediated by multiple brain regions, core components are centered in social and reward neural networks. These findings invite an interesting hypothesis that it is not a single brain region, but the combination of regions within the distributed neural networks and their coherent interaction that determine the type of other-regarding emotions and subsequent social decisions. Thus, a critical next step is to better understand fine-grained mechanisms underlying social rewards and emotions at the pathway level via electrophysiological decoding and pathway-selective intervention using well-controlled social task paradigms, the strategy of which has been developed in macaque monkeys [60]. Currently, the domain of comparisons between self and other is confined to rewards in monkey studies. However, other domains, such as the status and performance ability, would also be testable given that monkeys are sensitive to hierarchical relationships [61] and are equipped with metacognitive capability [62, 63, 64].