Neural computations underlying social risk sensitivity
Authors: George I Christopoulos
Brooks King-Casas
Nina Lauharatanahirun
Journal: Frontiers in Human Neuroscience (2012)
Discipline: NEUROSCIENCE & BEHAVIOR
Keywords: fMRI; individual differences; risk; social neuroscience; trust.
Affiliations: Virginia Tech Carilion Research Institute, Roanoke VA, USA.

Abstract:  Under standard models of expected utility, preferences over stochastic events are assumed to be independent of the source of uncertainty. Thus, in decision-making, an agent should exhibit consistent preferences, regardless of whether the uncertainty derives from the unpredictability of a random process or the unpredictability of a social partner. However, when a social partner is the source of uncertainty, social preferences can influence decisions over and above pure risk attitudes (RA). Here, we compared risk-related hemodynamic activity and individual preferences for two sets of options that differ only in the social or non-social nature of the risk. Risk preferences in social and non-social contexts were systematically related to neural activity during decision and outcome phases of each choice. Individuals who were more risk averse in the social context exhibited decreased risk-related activity in the amygdala during non-social decisions, while individuals who were more risk averse in the non-social context exhibited the opposite pattern. Differential risk preferences were similarly associated with hemodynamic activity in ventral striatum at the outcome of these decisions. These findings suggest that social preferences, including aversion to betrayal or exploitation by social partners, may be associated with variability in the response of these subcortical regions to social risk. 

Retracted: No

PubPeer comments:
 First, let me summarize and briefly comment on the results. To cite the conclusions of the paper precisely: u201dIndividuals who were more risk averse in the social context exhibited decreased risk-related activity in the amygdala during non-social decisions, while individuals who were more risk averse in the non-social context exhibited the opposite pattern. Differential risk preferences were similarly associated with hemodynamic activity in ventral striatum at the outcome of these decisions. These findings suggest that social preferences, including aversion to betrayal or exploitation by social partners, maybe associated with variability in the response of these subcortical regions to social risk.u201d However, the information about the data analysis provided in the Results section cast doubt on the results of the experiment and on the conclusions which are based on them. To cite the Results section precisely: u201cEstimates of RA in the social condition were strongly related to estimates of RA in the non-social condition across subjects (Spearman = 0.60, p 0.001). In both conditions, participants as a whole were risk averse (RA nonu2212social = 0.54, SD = 0.38; RA social = 0.59, SD = 0.32). To assess the extent to which RA differed between social and non-social contexts, we calculated an index of social risk sensitivity: SRS = RA social u2013 RA nonu2212social for each subject. Positive values of SRS (+SRS) signify that the participant exhibits higher risk aversion when a social partner determined the outcome of a risky choice compared to when the outcome was determined by a non-social gamble process. Similarly, negative values of SRS (u2212SRS) indicate greater risk aversion when the outcome was determined by a non-social versus social process.u201d And a few paragraphs later: u201cWithin the +SRS group, RA social was greater than RA nonu2212social (Wilcoxon Z = +3.5; P 0.001) and within the u2013SRS group, RA nonu2212social was greater than RA social (Wilcoxon Z = u22123.3; P 0.001).u201d If I understand this description of the analysis correctly, the participants were arbitrary divided into two groups which are by definition different in the SRS. Therefore, I see no reason to statistically test the difference between them. Not only that. This difference between groups was used as an interaction factor in the statistical analysis of the differences both in the behavior of the participants and its neural correlates as well. Apart from these two results, which are driven by the impossibility of not finding any statistically significant difference by definition, there are no other results suggesting any difference between social and non-social risk aversion either in the behaviour of the participants or their brain activity. Therefore, the conclusion about the existence of the differences is wrong. Please, be aware of citing these conclusions. It is very likely that they are wrong. ,