Neural Evidence for Individual and Cultural Variability in the Social Comparison Effect

Abstract

Although several studies have investigated the neural mechanism of social comparison, it remains unclear whether and how cultural membership, particularly independent versus interdependent cultures, may differentially shape the neural processes underlying social comparison. In the present functional magnetic resonance imaging (fMRI) study, we examined the behaviors and neural response patterns of Korean (i.e., interdependent culture) and American (i.e., independent culture) participants while performing a financial gambling task simultaneously and independently with a partner. Upon seeing the partner's income, greater modulation of the activity in the ventral striatum (VS) and the ventromedial prefrontal cortex (vmPFC) by relative gain was observed in Korean than American participants, suggesting greater sensitivity of Koreans toward social comparison. The strength of functional connectivity between the VS and the vmPFC predicted individual variability in the degree to which participants' decisions were affected by relative incomes. Additional model-based fMRI analysis further confirmed the primary role of the vmPFC in biasing decisions based on relative incomes. In summary, the present study provides the first neural evidence for decision biases due to social comparison and their individual and cultural variations.

Social Equality in the Number of Choice Options Is Represented in the Ventromedial Prefrontal Cortex

“…The neural responses to the reward outcomes were analyzed based on a three-factor model that sep-arated the effects of the outcome for SELF, that for OTHER, and equality in the outcomes between the players (see Materials and Methods). As expected, both the VS and vmPFC were sensitive to the reward outcome for SELF (Table 1), consistent with the large literature describing the role of these regions in processing monetary reward outcomes (Tricomi et al, 2004;Fliessbach et al, 2007;Mobbs et al, 2009;Haber and Knutson, 2010;Kang et al, 2013). Furthermore, the vmPFC showed an increased activation to the equality in the outcomes between the players (Table 1), in line with the results of previous studies reporting vmPFC activations to equitable monetary allocations between self and other (Tabibnia et al, 2008;Tricomi et al, 2010;Baumgartner et al, 2011;Zaki and Mitchell, 2011).…”

“…Together, the vmPFC seems to play a more important role than the VS in valuation of social information including equality in opportunity. Meanwhile, some other studies have reported that the vmPFC and VS show similar responses to social contexts (Tricomi et al, 2010;Bault et al, 2011;Kang et al, 2013). Future research will benefit from clarifying whether and how the vmPFC and VS are differentially involved in reward processing within a range of social contexts.…”

So pretty! The neural correlates of self-other vs familiar-other attractiveness comparisons

“…In the present study we did not observe, however, activations in the ventral striatum (VS) for downward comparisons, although such activations have been reported on several occasions before (Bault et al, 2011;Dohmen, Falk, Fliessbach, Sunde, & Weber, 2011;Du et al, 2013;Dvash, Gilam, Ben-Ze'ev, Hendler, & Shamay-Tsoory, 2010;Fliessbach et al, 2007Fliessbach et al, , 2012Grygolec, Coricelli, & Rustichini, 2012;Kang, Lee, Choi, & Kim, 2013;Lindner et al, 2015; for a review see . The VS constitutes one of the main structures of the reward system.…”

The neural bases for valuing social equality

“…(B) The vmPFC tracks the level of equality of opportunity between self and other, whereas the ventral striatum tracks the amount of opportunities available to self. design cultural neuroscience research (Chiao, 2010;Kang et al, 2013).…”