Neural Basis Of The Effect Of Economic Status On Responses To Unfairness

Social decision-making is greatly driven by fairness considerations.Economic status is also found playing an important role in the modulation of economic decision making.The present task and resting-state functional Magnetic Resonance Imaging(fMRI)study aimed at investigating how economic status modulated behavioral and neural responses to unfairness in a modified Ultimatum Game(UG).During the UG,participants played as responders and would be informed of the economic status of proposers before receiving offers during scanning.At the behavioral level,higher rejection rates and lower fairness ratings were revealed when proposers were in high economic status than in low economic status.At the neural level,bilateral dorsolateral prefrontal cortex(DLPFC),left anterior insula(AI)and right anterior cingulate cortex(ACC)showed increased activations to unfair offers.Moreover,greater activation of left thalamus was revealed when participants received unfair offers from proposers of both economic statuses,and also when received fair offers from proposers of the high rather than the low economic status.Stronger activation of right medial prefrontal cortex(MPFC)was revealed during acceptance to unfair offers in high economic status condition rather than in low economic status condition.Functional connectivity(FC)between DLPFC,thalamus and MPFC was significantly correlated with rejection rates and fairness ratings.When unfair offers were given by proposers in high economic status,rejection rates were negatively correlated with FC between right DLPFC and right MPFC,and fairness ratings were negatively correlated with FC between right thalamus and left MPFC.Taken together,these findings shed light on the modulation of proposers’economic status in responders’ unfairness-related social decision making.Moreover,FC between DLPFC,thalamus and MPFC engaged in the modulation of economic status on unfairness-related social decision making.