Neural mechanisms of the mood effects on third‐party responses to injustice after unfair experiences

Abstract

Behavioral decision theory argues that humans can adjust their third‐party responses (e.g., punishment and compensation) to injustice by integrating unfair experiences. Typically, the mood plays an important role in such a decision‐making process. However, the underlying neurocognitive bases remain largely unclear. We first employ a modified third‐party justice game in which an allocator split an amount of money between oneself and a receiver. The participants can reapportion the money as observers by choosing from the following three costly options: compensate the receiver, accept the current allocation, or punish the allocator. Then, a second‐party pseudo interaction is conducted where participants receive more (i.e., advantageous unfair experience) or less (i.e., disadvantageous unfair experience) than others. Finally, participants perform the third‐party justice game again after unfair experiences. Here, we use functional near‐infrared spectroscopy (fNIRS) to measure participants' brain activities during third‐party responses to injustice. We find participants compensate more to the receiver after advantageous unfair experience, which involved enhanced positive emotion, weakened sense of unfairness, and is linked with increased activity in the right dorsolateral prefrontal cortex (rDLPFC). In contrast, participants punish more on the allocator after disadvantageous unfair experience, which might primarily stem from their negative emotional responses, strong sense of unfairness, and is associated with significantly decreased activity in the rDLPFC. Our results suggest that third‐party compensation and punishment involved differential psychological and neural bases. Our findings highlight the crucial roles of second‐party unfair experiences and the corresponding mood responses in third‐party responses to unfairness, and unravel the intermediate neural architecture.

Musical Meter Induces Interbrain Synchronization during Interpersonal Coordination

“…The MFC-IBS was positively correlated with behavioral coordination in the metrical context. Our fNIRS results are consistent with previous findings, in which the MFC-IBS was observed during scenarios involving social interaction, including decision-making ( Zhang et al, 2017 ; Xie et al, 2022 ), cooperation ( Hu et al, 2017 ; Feng et al, 2020 ), and communication ( Balconi et al, 2021 ). In particular in various cooperative activities, pairs of participants showed enhanced MFC-IBS in case of specific populations and tasks, such as professional athletes ( Li et al, 2020 ), expert teachers ( Sun et al, 2020 ), and less creative individuals ( Xue et al, 2018 ), and providing positive feedback ( Lu et al, 2019a ) and demanding divergent thinking ( Lu et al, 2019b ).…”

Effects of Ingroup Identification on Ingroup Favouritism during Fairness Norm Enforcement

“…Nevertheless, the role of cognitive and emotional factors caused by encountering an injustice, such as perceptions of unfairness and anger, were not taken into account. Recent studies have found that negative emotional responses and unfairness perceptions of unfair distribution are associated with higher levels of rejection and punishment [ 61 , 62 ], so future research should explore how cognitive-emotional factors may impact this behaviour.…”

Acute stress during witnessing injustice shifts third-party interventions from punishing the perpetrator to helping the victim

“…However, they also involve distinct processes [ 5 ]. When facing injustice, both third-party responses correlate with the activation of fairness violations, e.g., the anterior insula (AI), anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (DLPFC), striatal reward circuitry, and emotional regulation systems, including the amygdala and ventromedial prefrontal cortex (vmPFC) [ 5 , 20 ]. Enhanced ventral striatal activity is further associated with punishing an offender instead of helping a victim [ 5 ].…”