Social Information Is Integrated into Value and Confidence Judgments According to Its Reliability

Abstract

How much we like something, whether it be a bottle of wine or a new film, is affected by the opinions of others. However, the social information that we receive can be contradictory and vary in its reliability. Here, we tested whether the brain incorporates these statistics when judging value and confidence. Participants provided value judgments about consumer goods in the presence of online reviews. We found that participants updated their initial value and confidence judgments in a Bayesian fashion, taking into account both the uncertainty of their initial beliefs and the reliability of the social information. Activity in dorsomedial prefrontal cortex tracked the degree of belief update. Analogous to how lower-level perceptual information is integrated, we found that the human brain integrates social information according to its reliability when judging value and confidence.SIGNIFICANCE STATEMENT The field of perceptual decision making has shown that the sensory system integrates different sources of information according to their respective reliability, as predicted by a Bayesian inference scheme. In this work, we hypothesized that a similar coding scheme is implemented by the human brain to process social signals and guide complex, value-based decisions. We provide experimental evidence that the human prefrontal cortex's activity is consistent with a Bayesian computation that integrates social information that differs in reliability and that this integration affects the neural representation of value and confidence.

Private but not social information validity modulates social conformity bias

“…Future work will be needed to investigate whether the lack of updating the weight on social information is specifically tied to the fact that social signal is simply uninformative in our task. As in previous research, our subjects differ considerably in their degrees of committing social conformity bias; it thus remains to be tested how subjects across social conformity bias spectrum would update their reliance on private and social information (Cook, Den Ouden, Heyes, & Cools, ; De Martino et al, ; Toelch, Bruce, Newson, Richerson, & Reader, ). Nevertheless, the present work illustrates and highlights intimate interactions between striatum and dmPFC in modulating people's social conformity propensity.…”

“…However, their activities were not correlated with individual differences of social conformity bias (Figure S4, Supporting Information). Together, these data implied that subjects who were characterized as less susceptible to the social information had to exert more cognitive control in order to conform to other people's opinions (Botvinick et al, ; De Martino et al, ; Klucharev et al, ).…”

“…How human choice behavior is influenced by the confluence of private and social information has been an active research topic in the fields of psychology and social neuroscience. Aided by formal decision theory and neuroimaging techniques, it has been shown that brain regions such as cingulate cortex (posterior cingulate cortex and dACC) and dmPFC play a critical role in conforming to social influences (Burke, Tobler, Schultz, & Baddeley, ; De Martino et al, ; Huber, Klucharev, & Rieskamp, ; Klucharev et al, ; Klucharev et al, ; Park, Goïame, O'Connor, & Dreher, ; Wu et al, ; Zaki et al, ). However, whether and how human can dynamically adjust their behavior based on the informational content remains largely unknown.…”

“…Through this lens, the reduced conformal adjustment from the downregulation of the medial frontal cortex in a previous transcranial magnetic stimulation study could be interpreted as either reducing the error signal between subject's own judgment and group opinion or simply impairing participant's tendency to follow group opinion (Klucharev et al, ; Klucharev et al, ). Interestingly, a recent study reported that the activities in the dmPFC seemed to track participants' resistance to social information (De Martino et al, ), suggesting its role might be more consistent with social conformity. Indeed, in our experiment, PPI analysis at the revelation of outcome feedback showed that the functional connectivity between striatum and the more anterior dmPFC was strengthened when private information was valid and subjects' subsequent choices were less vulnerable to the social influence (Figure a).…”

“…Regarding social conformity, previous literatures consistently demonstrate the importance of dmPFC/dACC, which are heavily involved in conflicts monitoring and cognitive control (Botvinick, Braver, Barch, Carter, & Cohen, ; Kragel et al, ). In social conformity setup where conflicts arise between private and social information, dmPFC shows greater activities and also predicts individual conformity behavior (De Martino, Bobadilla‐Suarez, Nouguchi, Sharot, & Love, ; Klucharev et al, ). It is hypothesized that the neural signals in the dmPFC might reflect the deviation of private judgment from group opinions or social norms, which leads to the adjustment of individual behavior (Klucharev et al, ; Wu, Luo, & Feng, ).…”