Intention affects fairness processing: Evidence from behavior and representational similarity analysis of event‐related potential signals

Abstract

In an ultimatum game, the responder must decide between pursuing self‐interest and insisting on fairness, and these choices are affected by the intentions of the proposer. However, the time course of this social decision‐making process is unclear. Representational similarity analysis (RSA) is a useful technique for linking brain activity with rich behavioral data sets. In this study, electroencephalography (EEG) was used to measure the time course of neural responses to proposed allocation schemes with different intentions. Twenty‐eight participants played an ultimatum game as responders. They had to choose between accepting and rejecting the fair or unfair money allocation schemes of proposers. The schemes were offered based on the proposer's selfish intention (monetary gain), altruistic intention (donation to charity), or ambiguous intention (unknown to the responder). We used a spatiotemporal RSA and inter‐subject RSA (IS‐RSA) to explore the connections between event‐related potentials (ERPs) after offer presentation and intention presentation with four types of behavioral data (acceptance, response time, fairness ratings, and pleasantness ratings). The spatiotemporal RSA results revealed that only response time variation was linked with the difference in ERPs at 432–592 ms after offer presentation on the posterior parietal and prefrontal regions. Meanwhile, the IS‐RSA results found a significant association between inter‐individual differences in response time and differences in ERP activity at 596–812 ms after the presentation of ambiguous intention, particularly in the prefrontal region. This study expands the intention‐based reciprocal model to the third‐party context and demonstrates that brain activity can represent response time differences in social decision‐making.

Intersubject representational similarity analysis uncovers the impact of state anxiety on brain activation patterns in the human extrastriate cortex

“…We are also aware that the sample size of neuroimaging studies is a crucial factor to be considered when conducting any analysis involving individual variations (44, 45). Although the sample size of the present study is comparable to recent studies utilizing the ISRSA approach to examine intersubject similarities between neural representations and other measurements (32, 46–50), the sample size should be carefully considered in future studies. In addition, a notable limitation of utilizing ISRSA should also be considered for future studies.…”

The neurocomputational signature of decision-making for unfair offers in females under acute psychological stress

“…In line with the inequality aversion model ( Fehr and Schmidt, 1999 ), individuals exhibit a tendency to reject unfair allocations when acting as responders in unfairness decision-making, even if doing so means punishing the proposer by sacrificing potential benefits the responder could have received. This pattern persists unless the proposers allocates all the resources exclusively to themselves ( Ogawa et al, 2023 ; Xu et al, 2023 ; Youssef et al, 2018 ). Our observation aligns with previous studies and underscores that as the level of fairness decreases, participants become increasingly inclined to reject the allocations.…”