Smiling as negative feedback affects social decision-making and its neural underpinnings

The impact of facial attractiveness and alleged personality traits on fairness decisions in the ultimatum game: Evidence from ERPs

In the mind of the beholder the personality and facial attractiveness of others are interrelated. However, how these specific properties are processed in the neurocognitive system and interact with each other while economic decisions are made is not well understood. Here, we combined the ultimatum game with EEG technology, to investigate how alleged personality traits and the perceived facial attractiveness of proposers of fair and unfair offers influence their acceptance by the responders. As expected, acceptance rate was higher for fair than unfair allocations. Overall, responders were more likely to accept proposals from individuals with higher facial attractiveness and with more positive personality traits. In ERPs, words denoting negative personality traits elicited larger P2 components than positive trait words, and more attractive faces elicited larger LPC amplitudes. Replicating previous findings, FRN amplitudes were larger to unfair than to fair allocations. This effect was diminished if the proposer's faces were attractive or associated with positive personality traits. Hence, facial attractiveness and the valence of personality traits seem to be evaluated independently and at different time points. Subsequent decision making about unfair offers is similarly influenced by high attractiveness and positive personality of the proposer, diminishing the negative response normally elicited by "unfair" proposals, possibly due a "reward" effect. In the ERPs to the proposals the effect of positive personality and attractiveness were seen in the FRN and P300 components but for positive personality traits the effect even preceded the FRN effect. Altogether, the present results indicate that both high facial attractiveness and alleged positive personality mitigate the effects of unfair proposals, with temporally overlapping but independent neurocognitive correlates.

Self-construal modulates context-based social comparison preferences in outcome evaluations

Self-construal (SC) describes how people perceive the relationship between themselves and others and is usually divided into interdependent and independent types. Several studies have been conducted on how people with independent and interdependent SC process their own and others' outcomes. However, few studies have investigated the influence of SC on outcome evaluation in a social comparison context. To explore this, we randomly assigned participants to interdependent and independent SC priming groups and analyzed the affects and electrophysiological responses generated when they played gambling games with two pseudo-players. The results showed that self-gambling state, SC, and social comparison interacted to influence feedback-related negativity (FRN). In the self-win condition, performances that differed from others elicited more negative FRN than evenness for both the interdependent and independent groups. In the self-loss condition, this effect was only found in the independent group. These results suggest that the outcome evaluation patterns in social contexts are not fixed but vary according to self-gambling state and SC.

Influence of advisees' facial feedback on subsequent advice-giving by advisors: Evidence from the behavioral and neurophysiological approach

Previous work has demonstrated the interpersonal implications of advisees' decisions (acceptance or rejection) on advisors' advice-giving behavior in subsequent exchanges. Here, using an ERP technique, we investigated how advisees' facial feedback (smiling, neutral, or frowning) accompanying their decisions (acceptance or rejection) influenced advisors' feedback evaluation from advisees and their advice-giving in subsequent exchanges. Behaviorally, regardless of whether the advice was accepted or rejected, advisors who received smiling-expression feedback would show higher willingness rates in subsequent advice-giving decisions, while advisors who received frowning-expression feedback would show lower willingness rates. On the neural level, in the feedback evaluation stage, the FRN and P3 responses were not sensitive to facial feedback. In contrast, frowning-expression feedback elicited a larger LPC amplitude than neutral- and smiling-expression feedback, regardless of whether the advice was accepted or rejected. In the advice decision stage, advisors who received neutral-expression feedback showed a larger N2 in making decisions than advisors who received frowning-expression feedback only after the advice was rejected. Additionally, Advisors who received smiling- and neutral-expression feedback showed a larger P3 in making decisions than advisors who received frowning-expression feedback only after the advice was accepted. In sum, the current findings extended previous research findings by showing that the effect of advisees' facial expressions on the advisors' advice-giving existed in multiple stages, including both the feedback evaluation stage and the advice decision stage.

Altered neural correlates of optimal decision-making in individuals with depressive status

Making optimal decisions by computing risk and benefit is necessary for humans. However, whether individuals with depressive status could utilize the optimal strategy to guide decision and its neural correlates remain unclear. The current study explored these issues by combining a decision task and high temporal-resolution electroencephalogram (EEG). The decision task involved an eight-box trial in which participants successively decided whether to open a box containing a potential reward or punishment, deciding to stop guaranteed they would retain the rewards already accumulated. Theoretically, the optimal strategy in the task was to stop at the fourth box, which had the largest expected value. We found that individuals with depressive status stopped fewer trials at the fourth box, relative to healthy controls, indicating their impaired optimal strategy during decision-making. Moreover, compared to healthy controls, individuals with depressive status showed weaker P2 amplitude and weaker beta-band oscillation at the frontocentral scalp when deciding whether to open the fourth box. Additionally, for healthy controls but not for individuals with depressive status, the P2 amplitude fully mediated the relationship between participants' degree of expected benefit (as reflected by the recreational risk-taking scale) and the frequency of trials stopped at the fourth box. Overall, this study revealed that the P2 amplitude and beta-band oscillation might explain the altered optimal decision-making in individuals with depressive status.

Others' Facial Expressions Influence Individuals Making Choices and Processing Feedback: The Event-Related Potential and Behavioral Evidence

To date, several studies have found the effect of facial expressions on trust decision, using the event-related potentials (ERPs). However, little is known about the neural mechanism underlying the modulation effect of facial expressions on making choices and subsequent outcome evaluation. In the present study, using an ERP technique, we investigated how the neural process of making choices and subsequent outcome evaluation were influenced by others' facial expressions for the first time. Specifically, participants played a modified version of the Trust Game, in which they watched a photo of the trustee before making choices. Critically, trustees' faces differed regarding emotional types (i.e., happy, neutral, or angry) and gender (i.e., female or male). Behaviorally, an interaction between expressions and gender was observed on investment rates. On the neural level, the N2 and P3 amplitudes were modulated by facial expressions in the making-choice stage. Additionally, the feedback-related P3 was also modulated by facial expressions. The present study proved the effect of facial expressions on making choices and subsequent outcome evaluation.

Top-down modulation impairs priming susceptibility in complex decision-making with social implications

Could social context variables prime complex decisions? Could top-down processes impair this priming susceptibility? Complex decisions have been mainly studied from economic and moral perspectives, and Dual Process Theories provide evidence of how these processes could be affected. To address these issues from a political perspective, online experiments were conducted. Participants (n = 252) were asked to choose a face from 4 options, each associated with different frequencies (repetition priming) or with phrases with different emotional valence (emotional priming), for an unspecified task (UST group) or an important task (IMT group). The most repeated face was chosen most in the UST group, and was associated with lower response times. Positive faces were equally chosen by both groups. To compare results in a more ecological situation, a social study was conducted during the 2019 Argentine Presidential Election, including online surveys (n = 3673) and analysis of news media mentioning candidates. The familiarity and trust to each candidate explained the voting-probability for most of them, as well as correlated with their frequency of mentions in the news, their positive associations, and election results. Our results suggest complex decision-making is susceptible to priming, depending on top-down modulation.

Neural responses to social partners' facial expressions are modulated by their social status in an interactive situation

Recently, several studies have found a recognition advantage for facial expressions, particularly angry expressions, when they appear on high-status faces rather than low-status faces. In the present study, we used event-related potentials (ERPs) to explore the influence of social status on the neural responses to others' facial expressions in a context of performance monitoring. Specifically, we used an interactive rank-inducing task (i.e., time estimation task) to manipulate social partners' status (high versus low) and then told participants that they would receive social feedback (i.e., happy, neutral, or angry) from social partners with high or low status after completing the task. ERP results revealed the preferential processing of high-status targets at both early (P1/N170/FRN) and late (P3) temporal stages of facial expression processing. Notably, larger FRN amplitudes elicited by feedback from high-status partners were observed in happy, neutral, and angry expression contexts, whereas larger P3 amplitudes elicited by feedback from high-status partners were only evident in both neutral and angry expression contexts but not in happy expression context. Together, the present study extended previous studies by showing that the perception of facial expressions could be modulated by target status at multiple stages.

I am entitled to it! Social power and context modulate disadvantageous inequity aversion

Previous research consistently indicated that social power influences one's fairness consideration. However, it is unclear how social power and context jointly affect inequity aversion and whether these processes would be manifested in brain activities. In this study, participants were randomly assigned into either high or low power condition and then took part in a modified ultimatum game (UG) as responders in both gain and loss contexts, with their event-related potentials (ERPs) recorded. Behavioral results showed that powerful participants were more likely to reject unfair offers in both contexts compared with powerless ones. In addition, powerful participants showed a more negative feedback-related negativity (FRN) loss-win difference wave (d-FRN) upon presentation of proposed offers compared with powerless participants only in the gain context. Interestingly, in a later time window, differences of P300 responses to proposed offers were modulated by social power in both gain and loss contexts. These results suggested that powerful people were more sensitive to fairness levels and FRN may manifest fairness consideration in a gain context, but not in a loss context. Meanwhile, P300 is sensitive to fairness considerations in both gain and loss contexts.

On second thought … the influence of a second stage in the ultimatum game on decision behavior, electro-cortical correlates and their trait interrelation

Previous EEG research only investigated one stage ultimatum games (UGs). We investigated the influence of a second bargaining stage in an UG concerning behavioral responses, electro-cortical correlates and their moderations by the traits altruism, anger, anxiety, and greed in 92 participants. We found that an additional stage led to more rejection in the 2-stage UG (2SUG) and that increasing offers in the second stage compared to the first stage led to more acceptance. The FRN during a trial was linked to expectance evaluation concerning the fairness of the offers, while midfrontal theta was a marker for the needed cognitive control to overcome the respective default behavioral pattern. The FRN responses to unfair offers were more negative for either low or high altruism in the UG, while high trait anxiety led to more negative FRN responses in the first stage of 2SUG, indicating higher sensitivity to unfairness. Accordingly, the mean FRN response, representing the trait-like general electrocortical reactivity to unfairness, predicted rejection in the first stage of 2SUG. Additionally, we found that high trait anger led to more rejections for unfair offer in 2SUG in general, while trait altruism led to more rejection of unimproving unfair offers in the second stage of 2SUG. In contrast, trait anxiety led to more acceptance in the second stage of 2SUG, while trait greed even led to more acceptance if the offer was worse than in the stage before. These findings suggest, that 2SUG creates a trait activation situation compared to the UG.

Neural Correlates of Successful Costly Punishment in the Ultimatum Game on a Trial-by-Trial Basis

Costly punishment describes decisions of an interaction partner to punish an opponent for violating rules of fairness at the expense of personal costs. Here, we extend the interaction process by investigating the impact of a socio-emotional reaction of the opponent in response to the punishment that indicates whether punishment was successful or not. In a modified Ultimatum game, emotional facial expressions of the proposer in response to the decision of the responder served as feedback stimuli. We found that both honored reward following acceptance of an offer (smiling compared to neutral facial expression) and successful punishment (sad compared to neutral facial expression) elicited a reward positivity, indicating that punishment was the intended outcome. By comparing the pattern of results with a probabilistic learning task, we show that the reward positivity on sad facial expressions was specific for the context of costly punishment. Additionally, acceptance rates on a trial-by-trial basis were altered according to P3 amplitudes in response to the emotional facial reaction of the proposer. Our results are in line with the concept of costly punishment as an intentional act following norm-violating behavior. Socio-emotional stimuli have an important influence on the perception and behavior in economic bargaining.