Observing heroic behavior and its influencing factors in immersive virtual environments.

Studying heroism in controlled settings presents challenges and ethical controversies due to its association with physical risk. Leveraging virtual reality (VR) technology, we conducted a three-study series with 397 participants from China to investigate heroic actions. Participants unexpectedly witnessed a criminal event in a simulated scenario, allowing observation of their tendency to physically intercept a thief. We examined situational factors (voluntariness, authority, and risk) and personal variables [gender, impulsivity, empathy, and social value orientation (SVO)] that may influence heroism. Also, the potential association between heroism and social conformity was explored. In terms of situational variables, voluntariness modulated participants' tendency to intercept the escaping thief, while perceived risk demonstrated its impact by interacting with gender. That is, in study 3 where the perceived risk was expected to be higher (as supported by an online study 5), males exhibited a greater inclination toward heroic behavior compared to females. Regarding other personal variables, the tendency to engage in heroic behavior decreased as empathy levels rose among males, whereas the opposite trend was observed for females. SVO influenced heroic behavior but without a gender interaction. Finally, an inverse relationship between heroism and social conformity was observed. The robustness of these findings was partly supported by the Chinese sample (but not the international sample) of an online study 4 that provided written descriptions of VR scenarios, indicating cultural variations. These results advance insights into motivational factors influencing heroism in the context of restoring order and highlight the power of VR technology in examining social psychological hypotheses beyond ethical constraints.

Sex difference in trait empathy is encoded in the human anterior insula.

Females are considered the more empathic sex. This conventional view, however, has been challenged in the past few decades with mixed findings. These heterogeneous findings could be caused by the fact that empathy is a complex and multifaceted construct. To clarify whether sex differences exist in certain dimensions of empathy and whether they are associated with specific neural bases, this study measured trait empathy using the interpersonal reactivity index (IRI) and collected brain structural and functional magnetic resonance imaging data in a large sample of healthy participants (206 males vs. 302 females). We found that females scored higher in the personal distress (PD) subscale than males, but they were comparable to males in other IRI subscales. Sex difference in PD was encoded by brain structural (e.g. gray matter volume in left anterior insula [AI]) and functional (e.g. resting-state functional connectivity between left AI and temporoparietal junction/inferior frontal gyrus) characteristics. Notably, the relationship between sex and PD was indirect-only and serially mediated by AI-associated structural and functional characteristics. Altogether, our results suggested that sex difference existed in self-oriented affective empathy (i.e. PD) and highlighted the importance of the AI, both structurally and functionally, in mediating the sex difference in trait empathy.

Why people engage in corrupt collaboration: an observation at the multi-brain level.

Recent studies suggest that corrupt collaboration (i.e. acquiring private benefits with joint immoral acts) represents a dilemma between the honesty and reciprocity norms. In this study, we asked pairs of participants (labeled as A and B) to individually toss a coin and report their outcomes; their collective benefit could be maximized by dishonestly reporting (a corrupt behavior). As expected, the likelihood of corrupt behavior was high; this probability was negatively correlated with player A's moral judgment ability but positively correlated with player B's empathic concern (EC). Functional near-infrared spectroscopy data revealed that the brain-to-brain synchronization in the right dorsolateral prefrontal cortex was associated with fewer corrupt behaviors, and that it mediated the relationship between player A's moral judgment ability and corrupt collaboration. Meanwhile, the right temporal-parietal junction synchronization was associated with more corrupt behaviors, and that it mediated the relationship between player B's EC and corrupt collaboration. The roles of these 2 regions are interpreted according to the influence of the honesty and reciprocity norms on corrupt collaboration. In our opinion, these findings provide insight into the underlying mechanisms and modulating factors of corrupt collaboration.

Verbal information exchange enhances collective performance through increasing group identification.

Information exchange is a key factor in the attainment of collective outcomes and the navigation of social life. In the current study, we investigated whether and how information exchange enhanced collective performance by combining behavioral and neuroimaging approaches from the perspective of multiparticipant neuroscience. To evaluate collective performance, we measured the collaborative problem-solving abilities of triads working on a murder mystery case. We first found that verbal information exchange significantly enhanced collective performance compared to nonverbal exchange. Moreover, both group sharing and group discussion positively contributed to this effect, with group discussion being more essential. Importantly, group identification mediated the positive effect of verbal information exchange on collective performance. This mediation was supported by higher interactive frequency and enhanced within-group neural synchronization (GNS) in the dorsolateral prefrontal cortex (DLPFC). Taken together, we provided a multiparticipant theoretical model to explain how verbal information exchange enhanced collective performance. Our findings deepen the insight into the workings of group decision-making.

Threat-induced anxiety and selfishness in resource sharing: Behavioral and neural evidence.

In real life, it is not unusual that we face potential threats (i.e., physical stimuli and environments that may cause harm or danger) with other individuals together, yet it remains largely unknown how threat-induced anxious feelings influence prosocial behaviors such as resource sharing. In this study, we investigated this question by combining functional magnetic resonance imaging and a novel paradigm. Together with an anonymous partner, each participant faced the possibility of receiving a 10-s noise administration, which had a low or high probability to be a threat (i.e., the intensity of noise can induce a high level of unpleasantness). Each participant first reported her/his immediate feeling of anxiety about the current situation (being threatened by the unpleasant noise), then decided how to split a number of resources (which could relieve the noise) between her/him and the partner. Behavioral results revealed that the participants showed a selfish bias in the threat conditions than in the safe conditions, and that self-reported anxiety feeling significantly predicted this bias. Functional magnetic resonance imaging results revealed that: (1) the activation level of the anterior insula was correlated with self-reported anxiety and (2) the connectivity between the anterior insula and the temporoparietal junction was sensitive to the modulating effect of anxiety on the selfish bias. These findings indicate the neural correlates of the association between threat-induced anxiety and prosocial tendencies in social interactions.

How resource sharing resists scarcity: the role of cognitive empathy and its neurobiological mechanisms.

Resource scarcity challenges individuals' willingness to share limited resources with other people. Still, lots of field studies and laboratory experiments have shown that sharing behaviors do not disappear under scarcity. Rather, some individuals are willing to share their scarce resources with others in a similar way as when the resource is abundant, which is crucial for the maintenance and development of human society. Here, we designed a novel paradigm in which subjects decided whether (and how much) to share an amount of "relieving resources" for counteracting unpleasant noises, which mimics real-life situations that people cost their own resources to help others escape from adversity. Overall, the robustness of resource sharing under scarcity was positively correlated with individual level of the cognitive component of empathy across two independent experiments. Resource insufficiency modulated the activations of several brain regions (including the TPJ, mPFC, and PCC) as well as the functional connection (from the rTPJ to the mPFC) within the mentalizing brain network, but the modulatory effect decreased as a function of cognitive empathy. We also applied the administration of oxytocin and found significant effects on sharing behavior among individuals with a higher level of cognitive empathy, but not their low-level counterparts. These findings highlight the importance of empathy to resource sharing under scarcity and explain the underlying neurobiological mechanisms.

Emotional autobiographical memory retrieval in time domain.

Autobiographical memory (AM) is an important psychological phenomenon that has significance for self-development and mental health. The psychological mechanisms of emotional AM retrieval and their association with individual emotional symptoms remain largely unclear in the literature. For this purpose, the current study provided cue words to elicit emotional AMs. Event-related potentials (ERPs) associated with the retrieval process of AMs were recorded and analyzed. We found that the ERP component N400 was sensitive to both emotional valence and retrieval state, such that its amplitude was larger for negative compared to positive AMs, and larger responses for unrecalled compared to recalled AMs. Further, the N400 amplitude in the positive recalled condition was correlated with individual difference in depression (measured by the Beck Depression Inventory). Another ERP component, the late positive potential (LPP), was also sensitive to emotional valence, such that its amplitude was larger (i.e., more positive-going) for positive compared to negative cues. No significant effect was observed on the early ERP components P1, N1, or P2. The current findings bring new understanding on the difference between positive and negative AMs retrieval in the time domain. Also, the importance of this difference to the individual level of depression is worth noting.

Prefrontal control of social influence in risk decision making.

To optimize our decisions, we may change our mind by utilizing social information. Here, we examined how changes of mind were modulated by Social Misalignment Sensitivity (SMS), egocentric tendency, and decision preferences in a decision-making paradigm including both risk and social information. Combining functional magnetic resonance imaging with computational modeling, we showed that both SMS and egocentric tendency modulated changes of mind under the influence of social information. While SMS was represented in the dorsal anterior cingulate cortex (dACC) and superior parietal gyrus (SPG) in the socially aligned situation, a distributed brain network was activated in the misaligned condition, including not only the dACC and SPG but also superior frontal gyrus and precuneus. These results suggest that SMS is related to a monitoring brain system, the scope of which varies according to the level of misalignment with social majority. The dorsolateral prefrontal cortex selectively interacted with SMS among the participants with a low switching threshold, indicating that its regulation on SMS may be sensitive to inter-individual variation. Our findings highlight the predominant roles of SMS and the prefrontal control system towards changes of mind under social influence.

Modulating social feedback processing by deep TMS targeting the medial prefrontal cortex: Behavioral and electrophysiological manifestations.

Neuroimaging studies have suggested that the medial prefrontal cortex (mPFC) is a key brain region for social feedback processing, but previous findings are largely based on correlational approaches. In this study, we use the deep transcranial magnetic stimulation (dTMS) to manipulate mPFC activity, then investigate participants' behavioral performance and event-related potentials (ERPs) during the Social Judgment Paradigm. A between-subject design was applied, such that both the active dTMS group and the sham group consisted of 30 participants. We found that the sham group was more likely to predict that they would be socially accepted (rather than rejected) by peers, but the same was not true in the active group. Additionally, this study is the first one to observe ERP signal changes in response to dTMS manipulation. ERP results show that both the expectation stage and the experience stage of social feedback processing were modulated by dTMS: (1) at the expectation stage, the P1 component was smaller in the active group than the sham group, while the stimulus-preceding negativity showed a stronger differentiating effect between positive and negative prediction in the sham group than the active group; (2) at the experience stage, the sensitivity of the late positive potential to the valence and predictability of social feedback was stronger in the sham group than the active group. These results improve our understanding about the relationship between the mPFC and social feedback processing.

Differentiating the abnormalities of social and monetary reward processing associated with depressive symptoms.

BACKGROUND: Reward dysfunction is a major dimension of depressive symptomatology, but it remains obscure if that dysfunction varies across different reward types. In this study, we focus on the abnormalities in anticipatory/consummatory processing of monetary and social reward associated with depressive symptoms. METHODS: Forty participants with depressive symptoms and forty normal controls completed the monetary incentive delay (MID) and social incentive delay (SID) tasks with event-related potential (ERP) recording. RESULTS: In the SID but not the MID task, both the behavioral hit rate and the ERP component contingent negative variation (CNV; indicating reward anticipation) were sensitive to the interaction between the grouping factor and reward magnitude; that is, the depressive group showed a lower hit rate and a smaller CNV to large-magnitude (but not small-magnitude) social reward cues compared to the control group. Further, these two indexes were correlated with each other. Meanwhile, the ERP components feedback-related negativity and P3 (indicating reward consumption) were sensitive to the main effect of depression across the MID and SID tasks, though this effect was more prominent in the SID task. CONCLUSIONS: Overall, we suggest that depressive symptoms are associated with deficits in both the reward anticipation and reward consumption stages, particularly for social rewards. These findings have a potential to characterize the profile of functional impairment that comprises and maintains depression.

The Neural Mechanism of the Social Framing Effect: Evidence from fMRI and tDCS Studies.

As an important cognitive bias, the framing effect shows that our decision preferences are sensitive to the verbal description (i.e., frame) of options. This study focuses on the neural underpinnings of the social framing effect, which is based on decision-making regarding other people. A novel paradigm was used in which participants made a trade-off between economic benefits and the feelings of others. This decision was described as either a "harm" to, or "not helping," other persons in two conditions (Harm frame vs Help frame). Both human males and females were recruited. Participants behaved more prosocially for Harm frame compared with Help frame, resulting in a significant social framing effect. Using functional magnetic resonance imaging, Experiment 1 showed that the social framing effect was associated with stronger activation in the temporoparietal junction (TPJ), especially its right part. The functional connectivity between the right TPJ (rTPJ) and medial prefrontal cortex predicted the social framing effect on the group level. In Experiment 2, we used transcranial direct current stimulation to modulate the activity of the rTPJ and found that the social framing effect became more prominent under anodal (excitatory) stimulation, while the nonsocial framing effect elicited by the economic gain/loss gambling frame remained unaffected. The rTPJ results might be associated with moral conflicts modulated by the social consequences of an action or different levels of mentalizing with others under different frame conditions, but alternative interpretations are also worth noting. These findings could help elucidate the psychological mechanisms of the social framing effect.SIGNIFICANCE STATEMENT Previous studies have suggested that the framing effect is generated from an interaction between the amygdala and anterior cingulate cortex. This opinion, however, is based on findings from nonsocial framing tasks. Recent research has highlighted the importance of distinguishing between the social and nonsocial framing effects. The current study focuses on the social framing effect and finds out that the temporoparietal junction and its functional connectivity with the medial prefrontal cortex play a significant role. Additionally, modulating the activity of this region leads to changes in social (but not nonsocial) framing effect. Broadly speaking, these findings help understand the difference in neural mechanisms between social and nonsocial decision-making. Meanwhile, they might be illuminating to promote helping behavior in society.

Prediction of trust propensity from intrinsic brain morphology and functional connectome.

Trust forms the basis of virtually all interpersonal relationships. Although significant individual differences characterize trust, the driving neuropsychological signatures behind its heterogeneity remain obscure. Here, we applied a prediction framework in two independent samples of healthy participants to examine the relationship between trust propensity and multimodal brain measures. Our multivariate prediction analyses revealed that trust propensity was predicted by gray matter volume and node strength across multiple regions. The gray matter volume of identified regions further enabled the classification of individuals from an independent sample with the propensity to trust or distrust. Our modular and functional decoding analyses showed that the contributing regions were part of three large-scale networks implicated in calculus-based trust strategy, cost-benefit calculation, and trustworthiness inference. These findings do not only deepen our neuropsychological understanding of individual differences in trust propensity, but also provide potential biomarkers in predicting trust impairment in neuropsychiatric disorders.

Males with low risk-taking propensity overestimate risk under acute psychological stress.

Arousing research has investigated stressed individuals' decision biases, but whether and how stress and individual traits interact to impact the underlying decision-making process is unknown. Here, we aim to explore the effect of acute stress on the interaction between the objective level of risk and subjective risk preference (i.e. risk-taking propensity). Eighty-three healthy males participated in the study. We adopted the Trier Social Stress Test (TSST) to induce acute psychological stress and categorized participants into the high or low risk-taking propensity (HRP/LRP) group according to their traits in daily life. The Balloon Analogue Risk Task (BART) was applied to measure their feedback processing in a risky decision task, while behavioral indexes and EEG signals were recorded. The results showed that stressful participants pumped fewer times than the controls, especially for the LRP under stress, indicating that they were more willing to avoid taking risks. Compared with the stressed HRP group, the stressed LRP showed higher salivary cortisol responses and a more positive FRN following positive feedback in higher risk levels. It implies that acute psychological stress leads the LRP to overestimate the risk probability and become more cautious in the sequential processing of risk. These findings highlight the role of the feedback process and individual traits in risky decision-making under stress.

Reward-driven attention alters perceived salience.

Many studies have revealed that reward-associated features capture attention. Neurophysiological evidence further suggests that this reward-driven attention effect modulates visual processes by enhancing low-level visual salience. However, no behavioral study to date has directly examined whether reward-driven attention changes how people see. Combining the two-phase paradigm with a psychophysical method, the current study found that compared with nonsalient cues associated with lower reward, the nonsalient cues associated with higher reward captured more attention, and increased the perceived contrast of the subsequent stimuli. This is the first direct behavioral evidence of the effect of reward-driven attention on low-level visual perception.

Amygdala-prefrontal connectivity modulates loss aversion bias in anxious individuals.

Anxious individuals tend to make pessimistic judgments in decision making under uncertainty. While this phenomenon is commonly attributed to risk aversion, loss aversion is a critical but often overlooked factor. In this study, we simultaneously examined risk aversion and loss aversion during decision making in high and low trait anxious individuals in a variable gain/loss gambling task during functional magnetic resonance imaging. Although high relative to low anxious individuals showed significant increased risk aversive behavior reflected by decreased overall gamble decisions, there was no group difference in subjective aversion to risk. Instead, loss aversion rather than risk aversion dominantly contributed to predict behavioral decisions, which was associated with attenuated functional connectivity between the amygdala-based emotional system and the prefrontal control regions. Our findings suggest a dominant role of loss aversion in maladaptive risk assessment of anxious individuals, underpinned by disorganization of emotion-related and cognitive-control-related brain networks.

Interpersonal relationships modulate outcome evaluation in a social comparison context: The pain and pleasure of intimacy.

Previous research has revealed that interpersonal relationships and social comparisons play important roles in evaluating outcomes. To our knowledge, how interpersonal relationships influence the process of outcome evaluations in a social comparison context remains largely unclear. In the current study, participants engaged in a simple gambling task with an acquaintance or a stranger and received outcome feedback. Behavioral results showed that participants' satisfaction level was sensitive to the outcome of their fellow players when participants won. In this condition, the satisfaction level was greater when their fellow players won rather than lost. Moreover, the satisfaction level was greater when their friends won compared with when a stranger won. Event-related potential (ERP) results showed that when participants won, the feedback-related negativity (FRN) was more negative going for other's losses than for other's gains. Moreover, the FRN was also more negative going for a stranger's gains than a friend's gains. In contrast, in the self-loss condition, the FRN was more negative going for other's gains than for other's losses regardless of the type of interpersonal relationship. These FRN findings indicate that the experience of other's outcomes is sensitive to participants' own outcomes. Importantly, the interpersonal relationship only showed its influence when both the self and others received monetary gains. Finally, the P300 registered participants' attention resource allocation toward monetary gains for themselves and for others, which was unaffected by the interpersonal relationship. This work reveals that outcome evaluation in various social comparison contexts is sensitive to the difference in interpersonal relationship in its early stage, labeled by the FRN.

The Dynamics of Belief Updating in Human Cooperation: Findings from inter-brain ERP hyperscanning.

Generally, successful cooperation can only be established when the interacting persons believe that they would not be betrayed; this belief can be updated by observing the other persons' actual choices. Thus, the process of belief updating plays an important role in conditional cooperation. Using the Prisoner's Dilemma Game (PDG) with event-related potential (ERP) hyperscanning, this study investigated the dynamics of belief updating in a dyad. During the task, participants were asked if they believed that their opponent would cooperate in the next trial, and their answers functioned as a self-reported index of reciprocal belief. The results suggested that this index shows strong associations with participants' behavioral choices (cooperate/betray). At the individual level, the amplitudes of the ERP components frontal P3a and parietal P3b elicited by the decision outcome were sensitive to belief updating. At the interpersonal level, the between-subject synchronization in P3b was higher than those in the other conditions when the paired participants confirmed each other's reciprocal beliefs. Since previous studies have linked the P3b with memory updating, we suggest that a cooperative relationship is built up when the memory systems (which support belief updating) of two interacting persons reach a high level of coordination. These findings may help explain how conditional cooperation develops between strangers.

Volume of motor area predicts motor impulsivity.

Impulsivity is a personality trait associated with many maladaptive behaviors. Trait impulsivity is typically divided into three different dimensions, including attentional impulsiveness, motor impulsiveness, and non-planning impulsiveness. In the present study, we examined the neuroanatomical basis of the multidimensional impulsivity trait. Eighty-four healthy participants were studied with structural magnetic resonance imaging. Multiple regression analyses revealed that the score of motor impulsiveness was negatively correlated with gray matter volumes of the right supplementary motor area and paracentral lobule. A machine-learning-based prediction analysis indicated that decreased gray matter volumes of the supplementary motor area and paracentral lobule strongly predicted the decrease in motor impulsiveness control. Our findings provide insights into the predictive role of motor brain structures in motor impulsivity and inhibition control.

Self-affirmation enhances the processing of uncertainty: An event-related potential study.

We proposed that self-affirmation can endow people with more cognitive resource to cope with uncertainty. We tested this possibility with an event-related potential (ERP) study by examining how self-affirmation influences ambiguous feedback processing in a simple gambling task, which was used to investigate risk decision-making. We assigned 48 participants randomly to the affirmation and non-affirmation (i.e., control) groups. All participants accepted the manipulation first and then completed the gambling task with an electroencephalogram (EEG) recording, in which participants might receive a positive (winning), negative (losing), or ambiguous (unknown valence) outcome after they made a choice. We considered both the feedback-related negativity (FRN) and P3 components elicited by the outcome feedback, which reflected the amount of cognitive resources being invested in the early and late stages of the outcome feedback processing, respectively. ERP results showed that ambiguous feedback elicited a larger FRN among affirmed participants than unaffirmed participants but exerted no influence on the P3. This finding suggests that self-affirmation may help coping with uncertainty by enhancing the early processing of uncertainty.

Individualized prediction of dispositional worry using white matter connectivity.

BACKGROUND: Excessive worry is a defining feature of generalized anxiety disorder and is present in a wide range of other psychiatric conditions. Therefore, individualized predictions of worry propensity could be highly relevant in clinical practice, with respect to the assessment of worry symptom severity at the individual level. METHODS: We applied a multivariate machine learning approach to predict dispositional worry based on microstructural integrity of white matter (WM) tracts. RESULTS: We demonstrated that the machine learning model was able to decode individual dispositional worry scores from microstructural properties in widely distributed WM tracts (mean absolute error = 10.46, p < 0.001; root mean squared error = 12.82, p < 0.001; prediction R2 = 0.17, p < 0.001). WM tracts that contributed to worry prediction included the posterior limb of internal capsule, anterior corona radiate, and cerebral peduncle, as well as the corticolimbic pathways (e.g. uncinate fasciculus, cingulum, and fornix) already known to be critical for emotion processing and regulation. CONCLUSIONS: The current work thus elucidates potential neuromarkers for clinical assessment of worry symptoms across a wide range of psychiatric disorders. In addition, the identification of widely distributed pathways underlying worry propensity serves to better improve the understanding of the neurobiological mechanisms associated with worry.