Self-other overlap and interpersonal neural synchronization serially mediate the effect of behavioral synchronization on prosociality

Collaborative imagination synchronizes representations of the future and fosters social connection in the present

From close friends to people on a first date, imagining a shared future appears fundamental to relationships. Yet, no previous research has conceptualized the act of imagination as a socially constructed process that affects how connected we feel to others. The present studies provide a framework for investigating imagination as a collaborative process in which individuals cocreate shared representations of hypothetical events-what we call collaborative imagination. Across two preregistered studies (N = 244), we provide evidence that collaborative imagination of a shared future fosters social connection in novel dyads-beyond imagining a shared future individually or shared experience in general. Subjective ratings and natural language processing of participants' imagined narratives illuminate the representational features of imagined events shaped by collaborative imagination. Together, the present findings have the potential to shift how we view the structure and function of imagination with implications for better understanding interpersonal relationships and collective cognition.

Moderate similarity leads to empathic concern, but high similarity can also induce personal distress towards others' pain

Empathic concern and personal distress are common vicarious emotional responses that arise when witnessing someone else's pain. However, the influence of perceived similarity on these responses remains unclear. In this study, we examined how perceived similarity with an injured target impacts vicarious emotional responses. A total of 87 participants watched a video of an athlete in pain preceded by a clip describing the athlete's trajectory, which indicated either high, moderate, or low similarity to the participants. Emotional self-reports, facial expressions, gaze behavior, and pupil diameter were measured as indicators of the participants' emotional responses. Participants in the moderate- and high-similarity groups exhibited greater empathic concern, as evidenced by their display of more sadness compared with those in the low-similarity group. Furthermore, those in the moderate-similarity group exhibited less avoidance by displaying reduced disgust, indicating lower personal distress compared with those in the low-similarity condition. Nevertheless, the high-similarity group displayed just as much disgust as the low-similarity group. These findings suggest that perceived similarity enhances empathic concern to others' suffering, but that high similarity can also lead to personal distress. Future studies on empathy should explore distinct vicarious states using multimodal measurements to further advance our understanding of these processes.

The effects of self-other overlap and group efficacy on group-based anger and collective action tendency: An online experimental study

Collective emotions and actions represent foundational constructs in social psychology, significantly influencing societal dynamics and responses. Within this framework, the Self-Other Overlap (SOO) - wherein individuals perceive minimal distinction between their own and others' identities - has been identified as an impactful factor at the interpersonal level. However, the extrapolation of SOO's implications at the collective, group level remains an underexplored domain in contemporary research. In addressing this lacuna, the present research endeavors to elucidate the multifaceted implications of SOO on group emotions and actions, contextualized within societal challenges such as "food hygiene problems". Utilizing validated instruments including the Self-Other Overlap Scale, Group-Based Anger Scale, Collective Action Tendency Scale, and Group Efficacy Scale for Coping Situations, this study adopts a tripartite situational experiment, engaging a collective sample of 359 participants, systematically recruited via the Credamo smart research platform to ensure representativeness. Study 1 examined the potential influence of variable SOO degrees on Group-Based Anger (GA) and Collective Action Tendency (CAT). Study 2 further refined the exploration, discerning the differential impacts of SOO targets on GA and CAT. Conclusively, Study 3 sought to ascertain the potential moderating role of Group Efficacy (GE) within the SOO-GA-CAT relationship. The empirical findings yielded several salient insights: notably, an augmentation in SOO levels corresponded with an amplification of GA and CAT. Furthermore, a delineation in SOO targets, specifically from external to ingroup entities, manifested in a pronounced augmentation of GA and CAT. Intriguingly, while elevated SOO predisposed heightened CAT, the modulatory effect of GE on CAT manifested predominantly in lower SOO contexts. In summation, the present study underscores the pivotal role of SOO magnitude and orientation as determinants of GA and CAT. The nuanced interplay between SOO degree and GE, particularly vis-à-vis CAT, provides a fresh scholarly perspective, contributing to the enriched understanding of group dynamics and collective behavioral paradigms.

An observation of a negative effect of social cohesion on creativity in musical improvisation

Although various social factors can significantly impact creative performance, it is still unclear how social cohesion (i.e., how close we feel to others) influences creativity. We therefore conducted two studies exploring the association between social cohesion and creativity within the domain of musical improvisation, a prime example of creative performance, which usually plays out in social contexts. The first study (n = 58 musical novices) showed that music-induced synchrony facilitates social cohesion. In our second study (n = 18 musical novices), we found that in two out of three experimental conditions, increased social cohesion is associated with less creative musical outcomes, as rated by nine expert musicians. In our subsequent analysis we related measures of social cohesion and creativity. This approach highlights how, within a musical setting, creativity unfolds in the context of social contingencies as social cohesion and related factors.

The shorter a man is, the more he defends fairness: relative height disadvantage promoting third-party punishment-evidence from inter-brain synchronization

Third-party punishment occurs in interpersonal interactions to sustain social norms, and is strongly influenced by the characteristics of the interacting individuals. During social interactions, height is the striking physical appearance features first observed, height disadvantage may critically influence men's behavior and mental health. Herein, we explored the influence of height disadvantage on third-party punishment through time-frequency analysis and electroencephalography hyperscanning. Two participants were randomly designated as the recipient and third party after height comparison and instructed to complete third-party punishment task. Compared with when the third party's height is higher than the recipient's height, when the third party's height is lower, the punishment rate and transfer amount were significantly higher. Only for highly unfair offers, the theta power was significantly greater when the third party's height was lower. The inter-brain synchronization between the recipient and the third party was significantly stronger when the third party's height was lower. Compared with the fair and medium unfair offers, the inter-brain synchronization was strongest for highly unfair offers. Our findings indicate that the height disadvantage-induced anger and reputation concern promote third-party punishment and inter-brain synchronization. This study enriches research perspective and expands the application of the theory of Napoleon complex.

Gender differences in cognitive and affective interpersonal emotion regulation in couples: an fNIRS hyperscanning

Emotion regulation is vital in maintaining romantic relationships in couples. Although gender differences exist in cognitive and affective strategies during 'intrapersonal' emotion regulation, it is unclear how gender differences through affective bonds work in 'interpersonal' emotion regulation (IER) in couples. Thirty couple dyads and 30 stranger dyads underwent functional near-infrared spectroscopy hyperscanning recordings when targets complied with their partner's cognitive engagement (CE) and affective engagement (AE) strategies after viewing sad and neutral videos. Behaviorally, for males, CE was less effective than AE in both groups, but little difference occurred for females between AE and CE. For couples, Granger causality analysis showed that male targets had less neural activity than female targets in CH06, CH13 and CH17 during CE. For inflow and outflow activities on CH06 and CH13 (frontopolar cortex), respectively, male targets had less activity in the CE condition than in the AE condition, while for outflow activities on CH 17 (dorsolateral prefrontal cortex), female targets had more activity in the CE condition than in the AE condition. However, these differences were not observed in strangers. These results suggest gender differences in CE but not in AE and dissociable flow patterns in male and female targets in couples during sadness regulation.

Virtual (Zoom) Interactions Alter Conversational Behavior and Interbrain Coherence

A growing number of social interactions are taking place virtually on videoconferencing platforms. Here, we explore potential effects of virtual interactions on observed behavior, subjective experience, and neural "single-brain" and "interbrain" activity via functional near-infrared spectroscopy neuroimaging. We scanned a total of 36 human dyads (72 participants, 36 males, 36 females) who engaged in three naturalistic tasks (i.e., problem-solving, creative-innovation, socio-emotional task) in either an in-person or virtual (Zoom) condition. We also coded cooperative behavior from audio recordings. We observed reduced conversational turn-taking behavior during the virtual condition. Given that conversational turn-taking was associated with other metrics of positive social interaction (e.g., subjective cooperation and task performance), this measure may be an indicator of prosocial interaction. In addition, we observed altered patterns of averaged and dynamic interbrain coherence in virtual interactions. Interbrain coherence patterns that were characteristic of the virtual condition were associated with reduced conversational turn-taking. These insights can inform the design and engineering of the next generation of videoconferencing technology.SIGNIFICANCE STATEMENT Videoconferencing has become an integral part of our lives. Whether this technology impacts behavior and neurobiology is not well understood. We explored potential effects of virtual interaction on social behavior, brain activity, and interbrain coupling. We found that virtual interactions were characterized by patterns of interbrain coupling that were negatively implicated in cooperation. Our findings are consistent with the perspective that videoconferencing technology adversely affects individuals and dyads during social interaction. As virtual interactions become even more necessary, improving the design of videoconferencing technology will be crucial for supporting effective communication.

Social relationship modulates advisor's brain response to advice-giving outcome evaluation: Evidence from an event-related potential study

Introduction

Advice-giving is a double-edged sword in social interaction, which could bring benefits or considerable losses for the advisee. However, whether the social relationship affects the time course of advisor's brain response to outcome evaluation after the advice-giving remains unclear.

Methods

In the present study, we used event-related potentials (ERPs) to investigate the modulation of social relationships on advisor's outcome feedback processing after the advice-giving and related neural activities.

Results

The results showed larger feedback-related negativity (FRN) to a loss than to a gain both when the friends accepted and rejected the advice, whereas this effect only existed when the strangers rejected the advice, but not when they accepted it. In contrast, the P3 results demonstrated the enhanced neural sensitivity when the strangers accepted the advice than rejected it despite leading to a loss, while a larger P3 amplitude was found when the friends accepted the advice than rejected it and brought a gain. The theta oscillation results in the friend group revealed stronger theta power to loss when the advisee accepted the advice than rejected it. However, this effect was absent in the stranger group.

Discussion

These results suggested that outcome evaluation in advice-giving was not only influenced by feedback valence and social reward, but also modulated by social relationships. Our findings contributed to the understanding of the neural mechanisms of advice-giving outcome evaluation in a social context.

Visible skin disease symptoms of another person reduce automatic imitation of their hand movements

Imitation is an important mechanism for social interaction and learning, and humans tend to imitate others automatically. While imitating others is often useful, it can backfire when imitation is incongruent with one's goals. For example, in forced-choice reaction time tasks, this tendency results in a reliable slowing of reactions if the observed and self-initiated actions are incompatible (compatibility effect). While imitation is commonly explained as a social phenomenon, previous results on the compatibility effect's dependence on social cues are inconsistent. However, in many previous studies, the associated social cues were easy to ignore by the participants. To make the social modifier more salient, the current study manipulated emotionally relevant aspects of the model hand itself in an imitation inhibition task by using models displaying skin disease symptoms which we expected to elicit (1) perceptions of dissimilarity and (2) disgust in participants. As predicted, participants' (n = 63) reaction times were influenced more by the incompatible actions of the symptom-free than the symptomatic model hand. However, both levels of self-reported disgust toward and self-other overlap with symptomatic hands were low and did not account for the observed effect on automatic imitation. Our findings show that automatic imitation depends on social factors if these are an integral part of the model and processed quickly, presumably due to their affective salience or the salience of the self-other distinction. Whether this effect is driven by emotional reactions to the model remains an open question.

Musical Meter Induces Interbrain Synchronization during Interpersonal Coordination

Music induces people to coordinate with one another. Here, we conduct two experiments to examine the underlying mechanism of the interbrain synchronization (IBS) that is induced by interpersonal coordination when people are exposed to musical beat and meter. In experiment 1, brain signals at the frontal cortex were recorded simultaneously from two participants of a dyad by using functional near-infrared spectroscopy (fNIRS) hyperscanning, while each tapped their fingers to aural feedback from their partner (coordination task) or from themselves (independence task) with and without the musical meter. The results showed enhanced IBS at the left-middle frontal cortex in case of the coordination task with musical beat and meter. The IBS was significantly correlated with the participants performance in terms of coordination. In experiment 2, we further examined the IBS while the participants coordinated their behaviors in various metrical contexts, such as strong and weak meters (i.e., high/low loudness of acoustically accenting beats). The results showed that strong meters elicited higher IBS at the middle frontal cortex than weak meters. These findings reveal that the musical beat and meter can affect brain-to-brain coupling in action coordination between people, and provide insights into the interbrain mechanism underlying the effects of music on cooperation.

The intrapersonal and interpersonal consequences of interpersonal synchrony

Interpersonal synchrony, the time-matching behaviors, is pervasive in human interactions. This resonation of movements or other forms was generally considered as one of critical survival skills for humans, as the important consequences of synchronizing with other persons in review of the empirical data in this article. These include positive affects towards and between interacting partners, but also include complex effects on the individual level. The intrapersonal effects of interpersonal synchrony are varied with positive or negative ones, including cognitive style, attitude bias, mood state, self-regulatory ability, and academic performance. At the interpersonal level, synchronized movement consistently affects the interaction with the partner and his/her affiliations, but they can be eliminated or magnified by several moderators, such as physiological arousal, shared intentionality, group bias, and musical rhythm. Finally, the research discussed the possible mechanisms underlying the effects of interpersonal synchrony in psychological and biological aspects.

It Takes Two: Interpersonal Neural Synchrony Is Increased after Musical Interaction

Music’s deeply interpersonal nature suggests that music-derived neuroplasticity relates to interpersonal temporal dynamics, or synchrony. Interpersonal neural synchrony (INS) has been found to correlate with increased behavioral synchrony during social interactions and may represent mechanisms that support them. As social interactions often do not have clearly delineated boundaries, and many start and stop intermittently, we hypothesize that a neural signature of INS may be detectable following an interaction. The present study aimed to investigate this hypothesis using a pre-post paradigm, measuring interbrain phase coherence before and after a cooperative dyadic musical interaction. Ten dyads underwent synchronous electroencephalographic (EEG) recording during silent, non-interactive periods before and after a musical interaction in the form of a cooperative tapping game. Significant post-interaction increases in delta band INS were found in the post-condition and were positively correlated with the duration of the preceding interaction. These findings suggest a mechanism by which social interaction may be efficiently continued after interruption and hold the potential for measuring neuroplastic adaption in longitudinal studies. These findings also support the idea that INS during social interaction represents active mechanisms for maintaining synchrony rather than mere parallel processing of stimuli and motor activity.

Middle Occipital Area Differentially Associates with Malevolent versus Benevolent Creativity: An fNIRS investigation

This study aimed to explore the neural correlates underlying idea generation during malevolent creativity (MC) using functional near-infrared spectroscopy (fNIRS). Participants were asked to solve problems during three types of creativity tasks: malevolent creativity task (MCT), benevolent creativity task (BCT), and alternative uses task (AUT). fNIRS was used to record individual cerebral activity during the tasks. The results revealed that participants demonstrated weaker neural activation in the right middle occipital area (rMO) and lower neural coupling (NC) between the right frontopolar cortex (rFPC) and rMO during MCT than during BCT and AUT. These suggest that r-MO activity and NC between the rFPC and rMO may distinguish between malevolent and benevolent forms of creative ideation.

Inter-Brain Neural Mechanism Underlying Turn-Based Interaction Under Acute Stress in Women: A Hyperscanning Study Using Functional Near-Infrared Spectroscopy

With the ever-changing social environment, stress has exerted a substantial influence on social interaction. The present study examined the underlying cognitive and neural mechanism on how acute stress affected the real-time cooperative and competitive interaction with four hypothesized path models. We used the hyperscanning technique based on functional near-infrared spectroscopy (fNIRS) device to examine brain-to-brain coherence within the dyads engaging Pattern Game under acute stress manipulated through Trier Social Stress Test for Groups. Behavioral results showed stressed dyads exhibited better cooperative performance and higher self-other overlap level during the cooperative session than dyads in the control group. The fNIRS results identified higher interpersonal brain synchronization in the right temporal-parietal junction (r-TPJ) stronger Granger causality from partner-to-builder during the cooperative session in the stress group when compared with the control group. Our results corroborated better performance in the cooperative context and further identified that brain-to-brain coherence in r-TPJ and self-other overlap serially mediated the effect of acute stress on cooperative performance.

Cooperation with partners of differing social experience: An fNIRS-based hyperscanning study

Previous studies have shown the brain synchronization of all team members while completing a collaborative task. Moreover, this effect is influenced by a team's compositional elements, such as gender (opposite or same) or relationships (i.e., friends, lovers, or strangers) among team members. However, whether interpersonal brain synchronization (IBS) is affected by team members' experience, as well as the temporal dynamics of such brain synchronization, remains to be investigated. In the current study, we combined behavioral methods and functional near-infrared spectroscopy-based hyperscanning to examine the effect of member experience on team cooperation by an adopted continuous joint drawing task with 21 student-student dyads (S-S dyads) and 22 teacher-student dyads (T-S dyads). The results revealed that team members with differing experiences (T-S dyads) perform better than those with similar ones (S-S dyads). Moreover, we observed IBS in the left frontopolar region (channel 11). However, we did not observe significant changes of the task-related IBS across time. Besides, IBS was negatively correlated with the participants' behavioral performance. Our findings demonstrate the importance of social experience in teamwork in the real world and suggest a possible mechanism for cooperation from a temporal and spatial perspective.

Posterior medial frontal cortex regulates sympathy: A TMS study

Harm to some elicits greater sympathy than harm to others. Here, we examine the role of posterior medial frontal cortex (PMFC) in regulating sympathy, and explore the potential role of PMFC in the related phenomena of mentalizing and representing others as connected with oneself. We down-regulated either PMFC or a control region (middle temporal visual area), then assessed feelings of sympathy for and self-other overlap with two characters described as having suffered physical harm, and who were framed as adversarial or affiliative, respectively. We also measured mentalizing performance with regard to inferring the cognitive and affective states of the adversarial character. As hypothesized, down-regulating PMFC increased sympathy for both characters. Whereas we had predicted that down-regulating PMFC would decrease mentalizing ability given the postulated role of PMFC in the mentalizing network, participants in the PMFC down-regulation condition evinced greater second-order cognitive inference ability relative to controls. We observed no effect of the TMS manipulation on self-other overlap, although sympathy and self-other overlap were positively correlated. These findings are discussed as they may inform understanding of the functional role(s) of PMFC in regulating responses broadly linked with empathy.

Interpersonal Neural Synchrony During Father-Child Problem Solving: An fNIRS Hyperscanning Study

Interpersonal neural synchrony (INS) has been previously evidenced in mother–child interactions, yet findings concerning father–child interaction are wanting. The current experiment examined whether fathers and their 5‐ to 6‐year‐old children (N = 66) synchronize their brain activity during a naturalistic interaction, and addressed paternal and child factors related to INS. Compared to individual problem solving and rest, father–child dyads showed increased INS in bilateral dorsolateral prefrontal cortex and left temporo‐parietal junction during cooperative problem solving. Furthermore, the father’s attitude toward his role as a parent was positively related to INS during the cooperation condition. These results highlight the implication of the father’s attitude to parenting in INS processes for the first time.

Capturing Human Interaction in the Virtual Age: A Perspective on the Future of fNIRS Hyperscanning

Advances in video conferencing capabilities combined with dramatic socio-dynamic shifts brought about by COVID-19, have redefined the ways in which humans interact in modern society. From business meetings to medical exams, or from classroom instruction to yoga class, virtual interfacing has permeated nearly every aspect of our daily lives. A seemingly endless stream of technological advances combined with our newfound reliance on virtual interfacing makes it likely that humans will continue to use this modern form of social interaction into the future. However, emergent evidence suggests that virtual interfacing may not be equivalent to face-to-face interactions. Ultimately, too little is currently understood about the mechanisms that underlie human interactions over the virtual divide, including how these mechanisms differ from traditional face-to-face interaction. Here, we propose functional near-infrared spectroscopy (fNIRS) hyperscanning—simultaneous measurement of two or more brains—as an optimal approach to quantify potential neurocognitive differences between virtual and in-person interactions. We argue that increased focus on this understudied domain will help elucidate the reasons why virtual conferencing doesn't always stack up to in-person meetings and will also serve to spur new technologies designed to improve the virtual interaction experience. On the basis of existing fNIRS hyperscanning literature, we highlight the current gaps in research regarding virtual interactions. Furthermore, we provide insight into current hurdles regarding fNIRS hyperscanning hardware and methodology that should be addressed in order to shed light on this newly critical element of everyday life.