You are in sync with me: neural correlates of interpersonal synchrony with a partner

Interacting with autistic virtual characters: intrapersonal synchrony of nonverbal behavior affects participants' perception

Temporal coordination of communicative behavior is not only located between but also within interaction partners (e.g., gaze and gestures). This intrapersonal synchrony (IaPS) is assumed to constitute interpersonal alignment. Studies show systematic variations in IaPS in individuals with autism, which may affect the degree of interpersonal temporal coordination. In the current study, we reversed the approach and mapped the measured nonverbal behavior of interactants with and without ASD from a previous study onto virtual characters to study the effects of the differential IaPS on observers (N = 68), both with and without ASD (crossed design). During a communication task with both characters, who indicated targets with gaze and delayed pointing gestures, we measured response times, gaze behavior, and post hoc impression formation. Results show that character behavior indicative of ASD resulted in overall enlarged decoding times in observers and this effect was even pronounced in observers with ASD. A classification of observer's gaze types indicated differentiated decoding strategies. Whereas non-autistic observers presented with a rather consistent eyes-focused strategy associated with efficient and fast responses, observers with ASD presented with highly variable decoding strategies. In contrast to communication efficiency, impression formation was not influenced by IaPS. The results underline the importance of timing differences in both production and perception processes during multimodal nonverbal communication in interactants with and without ASD. In essence, the current findings locate the manifestation of reduced reciprocity in autism not merely in the person, but in the interactional dynamics of dyads.

Culture, sex and social context influence brain-to-brain synchrony: an fNIRS hyperscanning study

BACKGROUND

Unique interpersonal synchrony occurs during every social interaction, and is shaped by characteristics of participating individuals in these social contexts. Additionally, depending on context demands, interpersonal synchrony is also altered. The study therefore aims to investigate culture, sex, and social context effects simultaneously in a novel role-play paradigm. Additionally, the effect of personality traits on synchrony was investigated across cultures, and a further exploratory analysis on the effects of these variables on pre- and post-session empathy changes was conducted.

METHODS

83 dyads were recruited in two waves from Singapore and Italy and took part in a within-subjects session where they interacted with each other as themselves (Naturalistic Conversation) and as others (Role-Play and Role Reversal). Big Five Inventory (administered pre-session) and Interpersonal Reactivity Index (administered pre- and post-session) were used as measures of personality and empathy respectively, while synchrony was measured using hyperscanning functional near-infrared spectroscopy in the prefrontal cortex. After data-preprocessing and preliminary analyses, a mixture of multiple linear regression and exploratory forward stepwise regression models were used to address the above study aims.

RESULTS

Results revealed significant main and interaction effects of culture, sex and social context on brain-to-brain synchrony, particularly in the medial left cluster of the prefrontal cortex, and a unique contribution of extraversion and openness to experience to synchrony in the Italian cohort only. Finally, culture-driven differences in empathy changes were identified, where significant increases in empathy across sessions were generally only observed within the Singaporean cohort.

CONCLUSIONS

Main findings indicate lowered brain-to-brain synchrony during role-playing activities that is moderated by the dyad's sex make-up and culture, implying differential processing of social interactions that is also influenced by individuals' background factors. Findings align with current literature that role-playing is a cognitively demanding activity requiring greater levels of self-regulation and suppression of self-related cognition as opposed to interpersonal co-regulation characterized by synchrony. However, the current pattern of results would be better supported by future studies investigating multimodal synchronies and corroboration.

Decoding the dynamic perception of risk and speed using naturalistic stimuli: A multivariate, whole-brain analysis

Time-resolved decoding of speed and risk perception in car driving is important for understanding the perceptual processes related to driving safety. In this study, we used an fMRI-compatible trackball with naturalistic stimuli to record dynamic ratings of perceived risk and speed and investigated the degree to which different brain regions were able to decode these. We presented participants with first-person perspective videos of cars racing on the same course. These videos varied in terms of subjectively perceived speed and risk profiles, as determined during a behavioral pilot. During the fMRI experiment, participants used the trackball to dynamically rate subjective risk in a first and speed in a second session and assessed overall risk and speed after watching each video. A standard multivariate correlation analysis based on these ratings revealed sparse decodability in visual areas only for the risk ratings. In contrast, the dynamic rating-based correlation analysis uncovered frontal, visual, and temporal region activation for subjective risk and dorsal visual stream and temporal region activation for subjectively perceived speed. Interestingly, further analyses showed that the brain regions for decoding risk changed over time, whereas those for decoding speed remained constant. Overall, our results demonstrate the advantages of time-resolved decoding to help our understanding of the dynamic networks associated with decoding risk and speed perception in realistic driving scenarios.

Impaired perception of a partner's synchronizing behavior reduces positive attitude toward humanoid robot in schizophrenia patients

As interpersonal synchrony plays a key role in building rapport, the perception of another agent's synchronizing behavior could be an important feature to assess, especially with patients with social deficits such as in schizophrenia. Twenty-four schizophrenia patients and twenty-four matched healthy controls performed jointly fitness movements with another agent embodied by a humanoid robot which was programmed to either synchronize with the participants or move at a fixed frequency with them. Self-report of participants' perception of the robot's synchronizing behavior was collected after each interaction. Results indicated that patients were impaired in their ability to accurately perceive the robot's synchronizing behavior. Patients' subjective perception of the robot's synchronizing behavior was associated with positive attitude toward it, suggesting that the belief to be synchronized with others could have similar impact on affiliation than real interpersonal synchrony. It leads to new perspectives for understanding social deficits in people with severe mental illness.

Inhibiting responses under the watch of a recently synchronized peer increases self-monitoring: evidence from functional near-infrared spectroscopy

Developing motor synchrony with a peer (through interventions such as the mirror game) can yield collaborative, cognitive and social benefits. However, it is also well established that observation by an audience can improve cognition. The combined and relative advantages offered by motor synchronization and audience effects are not yet understood. It is important to address this gap to determine the extent to which synchronizing activities might interact with the positive effects of an audience. In this preregistered study, we investigate the extent to which response inhibition may be improved when observed by a peer after motor synchronization with this peer. We compare behavioural and cortical (functional near-infrared spectroscopy; fNIRS) measures of inhibition between synchronized and non-synchronized dyads and find that the presence of a synchronized peer-audience introduces a speed-accuracy trade-off, consisting of slower reaction times and improved accuracy. This co-occurs with cortical activation in bilateral inferior frontal and middle prefrontal cortices, which are implicated in monitoring and maintenance of social alignment. Our findings have implications for carers and support people, who may benefit from synchronizing activities for rehabilitating inhibition and social skills in clinical settings.

Searching for the Metaverse: Neuroscience of Physical and Digital Communities

What distinguishes real-world communities from their online counterparts? Social and cognitive neuroscience research on social networks and collective intentionality will be used in the article to answer this question. Physical communities are born in places. And places engage "we-mode" neurobiological and cognitive processes as behavioral synchrony, shared attention, deliberate attunement, interbrain synchronization, and so on, which create coherent social networks of very different individuals who are supported by a "wisdom of crowd." Digital technologies remove physical boundaries, giving people more freedom to choose their activities and groups. At the same time, however, the lack of physical co-presence of community members significantly reduces their possibility of activating "we-mode" cognitive processes and social motivation. Because of this, unlike physical communities that allow interaction between people from varied origins and stories, digital communities are always made up of people who have the same interests and knowledge (communities of practice). This new situation disrupts the "wisdom of crowd," making the community more radical and less accurate (polarization effect), allowing influential users to wield disproportionate influence over the group's beliefs, and producing inequalities in the distribution of social capital. However, a new emergent technology-the Metaverse-has the potential to reverse this trend. Several studies have revealed that virtual and augmented reality-the major technologies underlying the Metaverse-can engage the same neurobiological and cognitive "we-mode" processes as real-world environments. If the many flaws in this technology are fixed, it might encourage people to engage in more meaningful and constructive interactions in online communities.

From distal to proximal to interactive: behavioral and brain synchrony during attraction, courtship, and sexual interaction-implications for clinical assessments of relationship style and quality

INTRODUCTION

Synchronous behaviors between individuals are nonverbal signs of closeness and common purpose. In the flow from initial attraction to intimate sexual interaction, attention and synchrony move from distal to proximal to interactive and are mediated by sensitized activation of neural systems for sexual motivation, arousal, and desire and those that recognize and mimic common facial and body movements between individuals. When reinforced by sexual pleasure and other relationship rewards, this results in the strengthening of attraction and bonding and the display of more common motor patterns. As relationships falter, nonverbal behaviors likely become asynchronous.

OBJECTIVES

To define behavioral, romantic, and sexual synchrony during phases of attraction and how their disruption can be observed and utilized by clinicians to assess individual relationship styles and quality.

METHODS

We review the literature on behavioral and attentional synchrony in humans and animals in an effort to understand experiential and innate mechanisms of synchrony and asynchrony and how they develop, as well as implications for attraction, relationship initiation, maintenance of romantic and sexual closeness, and relationship disintegration.

RESULTS

Evidence is presented that behavioral synchrony and the neural mechanisms that underlie it are vital to relationship formation and satisfaction.

CONCLUSION

Behavioral synchrony helps to create feelings of sexual and romantic synergy, cohesion, and arousal among individuals. Asynchrony is aversive and can spark feelings of discontent, aversion, and jealousy. Thus, observing patterns of nonverbal sexual and romantic synchrony between individuals offers insights into the potential quality of their relationships.

Beyond simultaneity: Temporal interdependence of behavior is key to affiliative effects of interpersonal synchrony in children

Interpersonal synchrony (IPS) is the temporal coordination of behavior during social interactions. IPS acts as a social cue signifying affiliation both when children witness IPS between others and when they experience it themselves. However, it is unclear which temporal qualities of IPS produce these effects and why. We hypothesized that both the simultaneity and temporal regularity of partners' actions would influence affiliation judgments and that subjective perceptions of IPS ("togetherness") would play a role in mediating these relations. In two online tasks, children aged 4 to 11 years listened to a pair of children tapping (witnessed IPS; n = 68) or themselves tapped with another child (experienced IPS; n = 63). Tapping partners were presented as real, but the sounds attributed to them were computer generated so that their temporal relations could be experimentally manipulated. The simultaneity and regularity of their tapping was systematically manipulated across trials. For witnessed IPS, both the simultaneity and regularity of partners' tapping significantly positively affected the perceived degree of affiliation between them. These effects were mediated by the perceived togetherness of the tapping. No affiliative effects of IPS were found in the experienced IPS condition. Our findings suggest that both the simultaneity and regularity of partners' actions influence children's affiliation judgments when witnessing IPS via elicited perceptions of togetherness. We conclude that temporal interdependence-which includes but is not limited to simultaneity of action-is responsible for inducing perceptions of affiliation during witnessed IPS.

Antiphase synchrony increases perceived entitativity and uniqueness: A joint hand-clapping task

In- and antiphase are the dominant patterns identified in the study of synchrony in relative phases. Many previous studies have focused on in-phase synchrony and compared it to asynchrony, but antiphase synchrony has yet not been the subject of much research attention. The limited findings on antiphase synchrony suggest that its role or nature is unclear or unstable in human interaction. To account for this factor, this study examined the possibility that antiphase synchrony simultaneously induced perceived entitativity and uniqueness. The results of an experiment employing a joint hand-clapping task supported this prediction. Further, the elevated feeling of uniqueness in those who experienced antiphase synchrony may have increased the self-other overlap for those who felt oneness with their partner, but it decreased overlap for those who did not. The theoretical implications for synchrony literature are discussed.

Children's perception of interpersonal coordination during joint painting

Interpersonal coordination is important for many joint activities. A special case of interpersonal coordination is synchronization, which is required for the performance of many activities, but is also associated with diverse positive social and emotional attributes. The extent to which these effects are due to the reliance on synchrony for task performance or to its specific rhythmic characteristics, is not clear. To address these questions, we considered a more general form of interpersonal coordination, implemented during joint artmaking. This is a non-typical context for interpersonal coordination, not required for task success, and smoother and more loosely-structured than more standard forms of synchronous coordination. Therefore, comparing interpersonal coordination with non-coordination during shared painting, could help reveal general social-emotional reactions to coordination. To gain a more 'naïve' perspective we focused on children, and staged coordinated and non-coordinated art interactions between an adult and a child, asking child observers to judge various variables reflecting the perceived bond between the painters. We found an overall stronger perceived bond for the coordination condition. These results demonstrate that even a non-typical form of interpersonal coordination could be attributed with positive social and emotional qualities, a capacity revealed already in childhood, with possible implications for development.

The effect of action contingency on social perception is independent of person-like appearance and is related to deactivation of the frontal component of the self-agency network

The detection of object movement that is contingent on one's own actions (i.e., movements with action contingency) influences social perception of the object; such interactive objects tend to create a good impression. However, it remains unclear whether neural representation of action contingency is associated with subsequent socio-cognitive evaluation of "contacting agents", or whether the appearance of agents (e.g., face- or non-face-like avatars) is essential for this effect. In this study, we conducted a functional magnetic resonance imaging (fMRI) task with two phases: contact (contact with face- or non-face-like avatars moving contingently or non-contingently) and recognition (rating a static image of each avatar). Deactivation of the frontoparietal self-agency network and activation of the reward network were the main effects of action contingency during the contact phase, consistent with previous findings. During the recognition phase, static avatars that had previously moved in a contingent manner deactivated the frontal component of the frontoparietal network (bilateral insula and inferior-middle frontal gyri), regardless of person-like appearance. Our results imply that frontal deactivation may underlie the effect of action contingency on subsequent social perception, independent of person-like appearance.

Synchrony During Online Encounters Affects Social Affiliation and Theory of Mind but Not Empathy

Moving together in time affects human social affiliation and cognition. However, it is unclear whether these effects hold for on-line video meetings and whether they extend to empathy (understanding or sharing others' emotions) and theory of mind (ToM; attribution of mental states to others). 126 young adult participants met through online video in unacquainted pairs. Participants either performed 3 min of synchronous arm movements paced by sounds (n = 40), asynchronous movements (n = 46) or a small talk condition (n = 40). In a subsequent empathy task, participants engaged in a conversation. A video recording of this conversation was played back, and each participant rated, at predetermined time points, how they felt and how they thought their partner felt. From this we calculated empathic accuracy (accuracy of the estimation of the other's emotions) and emotional congruence (emotion sharing). ToM was measured by showing videos of geometrical shapes interacting and asking the participants to describe what happened, measuring the amount of intentionality. We found that participants in the synchrony condition rated feeling greater closeness and similarity to their partners relative to the asynchronous condition. Further, participants in the synchrony group tended to ascribe more intentionality to the abstract shapes than participants in asynchrony condition, suggesting greater ToM. Synchrony and asynchrony groups did not reliably differ in empathic accuracy nor emotional congruence. These results suggest that moving in synchrony has effects on social affiliation measures even in online encounters. These effects extend to ToM tendencies but not empathic accuracy or emotion sharing. These results highlight the potential of synchronous movement in online encounters to affect a subset of social cognition and affiliation measures.

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.

Individual differences in social attachment: A multi-disciplinary perspective

Social behavior varies across both individuals and species. Research to explain this variation falls under the purview of multiple disciplines, each with its own theoretical and empirical traditions. Integration of these disciplinary traditions is key to developing a holistic perspective. Here, we review research on the biology of social attachment, a phenomena in which individuals develop strong affective connections to one another. We provide a historical overview of research on social attachment from psychological, ethological and neurobiological perspectives. As a case study, we describe work on pair-bonding in prairie voles, a socially monogamous rodent. This specific topic takes advantage of many biological perspectives and techniques to explain social bonds. Lastly, we conclude with an overview of multi-dimensional conceptual frameworks that can be used to explain social phenomena, and we propose a new framework for research on individual variation in attachment behavior. These conceptual frameworks originate from philosophy, physics, ethology, cognitive science and neuroscience. The application and synthesis of such frameworks offers a rich opportunity to advance understanding of social behavior and its mechanisms.

Altered activation in the action observation system during synchronization in high loneliness individuals

Lonely people tend to evaluate social exchanges negatively and to display difficulties in interactions. Interpersonal synchronization is crucial for achieving positive interactions, promoting affinity, closeness, and satisfaction. However, little is known about lonely individuals' ability to synchronize and about their brain activity while synchronizing. Following the screening of 303 participants, we recruited 32 low and 32 high loneliness participants. They were scanned while engaged in movement synchronization, using a novel dyadic interaction paradigm. Results showed that high loneliness individuals exhibited a reduced ability to adapt their movement to their partner's movement. Intriguingly, during movement adaptation periods, high loneliness individuals showed increased activation in the action observation (AO) system, specifically in the inferior frontal gyrus and the inferior parietal lobule. They did not show increased activation in the dorsomedial prefrontal cortex, which in the context of synchronization was suggested to be related to gap-monitoring. Based on these findings, we propose a model according to which lonely people may require stronger activation of their AO system for alignment, to compensate for some deficiency in their synchronization ability. Despite this hyperactivation, they still suffer from reduced synchronization capacity. Consequently, synchronization may be a relevant intervention area for the amelioration of loneliness.

Liking as a balance between synchronization, complexity and novelty

Synchronization has been identified as a key aspect in social bonding. While synchronization could be maximized by increasing the predictability of an interaction, such predictability is in tension with individuals' level of interest, which is tied to the interaction's complexity and novelty. In this study, we tested the interplay between synchronization and interest. We asked 104 female dyads to play the Mirror Game, in which they had to move their hands as coordinately as possible, and then report how much they liked each other. Utilizing information theory and video processing tools, we found that a combination of movement synchronization and complexity explained liking almost two times better than movement synchronization alone. Moreover, we found that people initiated novel and challenging interactions, even though they paid a price-being less synchronized. Examining the interactions' dynamics, we found that people who liked each other moved in a more synchronized, complex, and novel manner during most of the interaction. This suggests that in addition to synchronization, maintaining interest may be critical for positive social bonding. Thus, we propose a new framework in which balancing synchronization and interest, rather than merely maximizing synchronization, optimizes the interaction quality.

Interpersonal Synchronization Protects Against the Antisocial Outcomes of Frustration

Prosociality improves with interpersonal synchronization-the temporal coordination of movement across individuals. We tested whether the benefits of interpersonal synchronization extend to temporary circumstances of induced frustration, where negative changes in prosociality are expected as a result. Participants performed two joint tasks-synchronization versus non-synchronization. Each task was performed twice, with high versus low induced frustration. After each joint task, prosociality was measured both with explicit tests, in which participants were aware of the test goal, and implicit ones, where they were less aware. Frustration levels per task were also reported. Results showed that increase in frustration led to decrease in implicit prosociality after the non-synchronization task, but not after synchronization, suggesting that interpersonal synchronization attenuates the antisocial outcomes of frustration. In addition, our study highlights the advantages of implicit measures of prosociality, among which the test we created (Interpersonal Trust Test) may stand as a useful resource in future experimental research.

Adaptive Empathy: A Model for Learning Empathic Responses in Response to Feedback

Empathy is usually deployed in social interactions. Nevertheless, common measures and examinations of empathy study this construct in isolation from the person in distress. In this article we seek to extend the field of examination to include both empathizer and target to determine whether and how empathic responses are affected by feedback and learned through interaction. Building on computational approaches in feedback-based adaptations (e.g., no feedback, model-free and model-based learning), we propose a framework for understanding how empathic responses are learned on the basis of feedback. In this framework, adaptive empathy, defined as the ability to adapt one's empathic responses, is a central aspect of empathic skills and can provide a new dimension to the evaluation and investigation of empathy. By extending existing neural models of empathy, we suggest that adaptive empathy may be mediated by interactions between the neural circuits associated with valuation, shared distress, observation-execution, and mentalizing. Finally, we propose that adaptive empathy should be considered a prominent facet of empathic capabilities with the potential to explain empathic behavior in health and psychopathology.

Exploring gene-culture coevolution in humans by inferring neuroendophenotypes: A case study of the oxytocin receptor gene and cultural tightness

The gene-culture coevolution (GCC) framework has gained increasing prominence in the social and biological sciences. While most studies on human GCC concern the evolution of low-level physiological traits, attempts have also been made to apply GCC to complex human traits, including social behavior and cognition. One major methodological challenge in this endeavor is to reconstruct a specific biological pathway between the implicated genes and their distal phenotypes. Here, we introduce a novel approach that combines data on population genetics and expression quantitative trait loci to infer the specific intermediate phenotypes of genes in the brain. We suggest that such "neuroendophenotypes" will provide more detailed mechanistic insights into the GCC process. We present a case study where we explored a GCC dynamics between the oxytocin receptor gene (OXTR) and cultural tightness-looseness. By combining data from the 1000 Genomes project and the Gene-Tissue-Expression project (GTEx), we estimated and compared OXTR expression in 10 brain regions across five human superpopulations. We found that OXTR expression in the anterior cingulate cortex (ACC) was highly variable across populations, and this variation correlated with cultural tightness and socio-ecological threats worldwide. The mediation models also suggested possible GCC dynamics where the increased OXTR expression in the ACC mediates or emerges from the tight culture and higher socio-ecological threats. Formal selection scans further confirmed that OXTR alleles linked to enhanced receptor expression in the ACC underwent positive selection in East Asian countries with tighter social norms. We discuss the implications of our method in human GCC research.

[Re]moving Bodies - A Shared Diminished Reality Installation for Exploring Relational Movement

In this article we explore an epistemic approach we name dis/embodiment and introduce "Articulations," an interdisciplinary project bringing together Virtual Reality (VR) designers, cognitive scientists, dancers, anthropologists, and human-machine interaction specialists. According to Erin Manning, our sense of self and other emerges from processes of bodying and relational movement (becoming oneself by moving in relation with the world). The aim of the project is to exploit the potential of multi-person VR in order to explore the intersubjective dynamics of relational movement and bodying, and to do so with scientific, artistic and therapeutic purposes in mind. To achieve this bridge, we bring up a novel paradigm we name "Shared Diminished Reality". It consists in using minimalist representation to instantiate users' bodies in the virtual space. Instead of using humanoid avatars or full body skeletons, we reduce the representation of the moving bodies to three spheres whose trajectories reflect the tracking of the head and the two wrists. This "diminished"virtual rendition of the body-in-movement, we call dis/embodiment. It provides a simple but clear experience of one's own responsive movement in relation to the world and other bodies. It also allows for subtle manipulations of bodies' perceptual and cross-perceptual feedback and simplifies the tracking and the analysis of movements. After having introduced the epistemic framework, the basic architecture, and the empirical method informing the installation, we present and discuss, as a proof-of-concept, some data collected in a situated experiment at a science-art event. We investigate motion patterns observed in different experimental conditions (in which participants either could or could not see the representation of their own hands in the virtual space) and their relation with subjective reports collected. We conclude with reflection on further possibilities of our installation in exploring bodying and relational movement.

Language and Movement Synchronization in Dyadic Psychotherapeutic Interaction - A Qualitative Review and a Proposal for a Classification

In individual psychotherapy verbal communication and movement synchronization are closely interrelated. The microanalysis of timing, rhythm and gestalt of movement has established dynamic movement coordination as a systemic property of the dyadic interaction. Movement synchronization supports and enhances the unfolding of linguistic meaning. In order to substantiate the importance of the concept of synchrony for adult psychotherapy we review evidence from developmental psychology and discuss approaches to measure synchrony with particular reference to the naturalistic setting of dyadic psychotherapy. As the concept of synchrony is still ambiguous, and the respective interactional phenomena are ephemeral and fluid, in the current paper we suggest a set of five criteria for the description of synchronization in general terms and eight additional criteria which specifically enable the description of phenomena of movement synchronization. The five general dimensions are: (1) context, (2) modality, (3) resources, (4) entrainment, and (5) time-lag. The eight categories for the description of movement synchrony are: (1) spatial direction, (2) amplitude, (3) sinuosity, (4) duration, (5) event structure, (6) phase, (7) frequency, and (8) content. To understand the process of participatory sense-making and the emergence of meaning in psychotherapy, synchrony research has to cope with the multimodality of the embodied interaction. This requires an integrated perspective of movement and language. A system for the classification of synchrony phenomena may contribute to the linking of variations and patterns of movement with language and linguistic utterances.

Experiencing Happiness Together Facilitates Dyadic Coordination through the Enhanced Interpersonal Neural Synchronization

Experiencing positive emotions together facilitates interpersonal understanding and promotes subsequent social interaction among individuals. However, the neural underpinnings of such emotional-social effect remain to be discovered. Current study employed the fNIRS-based hyperscanning to investigate the above mentioned relationship. After participants in dyad watching movie clips with happily or neutral emotion, they were asked to perform the interpersonal cooperative task, with their neural activation of prefrontal cortex (PFC) being recorded simultaneously via functional near infrared spectroscopy. Results suggested that compared with the neutral movie watching together, a higher interpersonal neural synchronization (INS) in left inferior frontal gyrus during participant dyads watching happiness movie together. Subsequently, dyads in happiness showed more effective coordination interaction during performed the interpersonal cooperation task compared to those in the neutral condition, and such facilitated effect was associated with increased cooperation-related INS at left middle frontal cortex. A mediation analysis showed that the coordination interaction fully mediated the relationship between the emotion-induced INS during the happiness movie-viewing and the cooperation-related INS in interpersonal cooperation. Taken together, our findings suggest that the faciliatory effect experiencing happiness together has on interpersonal cooperation can be reliably reflected by the INS magnitude at the brain level.

Bridging the gap between emotion and joint action

Our daily human life is filled with a myriad of joint action moments, be it children playing, adults working together (i.e., team sports), or strangers navigating through a crowd. Joint action brings individuals (and embodiment of their emotions) together, in space and in time. Yet little is known about how individual emotions propagate through embodied presence in a group, and how joint action changes individual emotion. In fact, the multi-agent component is largely missing from neuroscience-based approaches to emotion, and reversely joint action research has not found a way yet to include emotion as one of the key parameters to model socio-motor interaction. In this review, we first identify the gap and then stockpile evidence showing strong entanglement between emotion and acting together from various branches of sciences. We propose an integrative approach to bridge the gap, highlight five research avenues to do so in behavioral neuroscience and digital sciences, and address some of the key challenges in the area faced by modern societies.

From Gaze Perception to Social Cognition: The Shared-Attention System

When two people look at the same object in the environment and are aware of each other's attentional state, they find themselves in a shared-attention episode. This can occur through intentional or incidental signaling and, in either case, causes an exchange of information between the two parties about the environment and each other's mental states. In this article, we give an overview of what is known about the building blocks of shared attention (gaze perception and joint attention) and focus on bringing to bear new findings on the initiation of shared attention that complement knowledge about gaze following and incorporate new insights from research into the sense of agency. We also present a neurocognitive model, incorporating first-, second-, and third-order social cognitive processes (the shared-attention system, or SAS), building on previous models and approaches. The SAS model aims to encompass perceptual, cognitive, and affective processes that contribute to and follow on from the establishment of shared attention. These processes include fundamental components of social cognition such as reward, affective evaluation, agency, empathy, and theory of mind.

Acting with shared intentions: A systematic review on joint action coordination in Autism Spectrum Disorder

BACKGROUND

Joint actions, described as a form of social interaction in which individuals coordinate their actions in space and time to bring about a change in the environment, rely on sensory-motor processes that play a role in the development of social skills. Two brain networks, associated with "mirroring" and "mentalizing", are engaged during these actions: the mirror neuron and the theory of mind systems. People with autism spectrum disorder (ASD) showed impairment in interpersonal coordination during joint actions. Studying joint action coordination in ASD will contribute to clarify the interplay between sensory-motor and social processes throughout development and the interactions between the brain and the behavior.

METHOD

This review focused on empirical studies that reported behavioral and kinematic findings related to joint action coordination in people with ASD.

RESULTS

Literature on mechanisms involved in the joint action coordination impairment in ASD is still limited. Data are controversial. Different key-components of joint action coordination may be impaired, such as cooperative behavior, temporal coordination, and motor planning.

CONCLUSIONS

Interpersonal coordination during joint actions relies on early sensory-motor processes that have a key role in guiding social development. Early intervention targeting the sensory-motor processes involved in the development of joint action coordination could positively support social skills.

When our hearts beat together: Cardiac synchrony as an entry point to understand dyadic co-regulation in couples

The degree to which romantic partners' autonomic responses are coordinated, represented by their pattern of physiological synchrony, seems to capture important aspects of the reciprocal influence and co-regulation between spouses. In this study, we analyzed couple's cardiac synchrony as measured by heart rate (HR) and heart rate variability (HRV). A sample of 27 couples (N = 54) performed a structured interaction task in the lab where they discussed positive and negative aspects of the relationship. During the interaction, their cardiac measures (HR and HRV) were recorded using the BIOPAC System. Additional assessment, prior to the lab interaction task, included self-report measures of empathy (Interpersonal Reactivity Index and Interpersonal Reactivity Index for Couples) and relationship satisfaction (Revised Dyadic Adjustment Scale). Synchrony computation was based on the windowed cross-correlation of both partner's HR and HRV time series. In order to control for random synchrony, surrogate controls were created using segment-wise shuffling. Our results confirmed the presence of cardiac synchrony during the couple's interaction when compared to surrogate testing. Specifically, we found evidence for negative (antiphase) synchrony of couple's HRV and positive (in-phase) synchrony of HR. Further, both HRV and HR synchronies were associated with several dimensions of self-report data. This study suggests that cardiac synchrony, particularly, the direction of the covariation in the partners' physiological time series, may have an important relational meaning in the context of marital interactions.

Brief Report: Classification of Autistic Traits According to Brain Activity Recoded by fNIRS Using ε-Complexity Coefficients

Individuals with ASD have been shown to have different pattern of functional connectivity. In this study, brain activity of participants with many and few autistic traits, was recorded using an fNIRS device, as participants preformed an interpersonal synchronization task. This type of task involves synchronization and functional connectivity of different brain regions. A novel method for assessing signal complexity, using ε-complexity coefficients, applied for the first i.e. on fNIRS recording, was used to classify brain recording of participants with many/few autistic traits. Successful classification was achieved implying that this method may be useful for classification of fNIRS recordings and that there is a difference in brain activity between participants with low and high autistic traits as they perform an interpersonal synchronization task.

Differences in cortical activation patterns during action observation, action execution, and interpersonal synchrony between children with or without autism spectrum disorder (ASD): An fNIRS pilot study

Engaging in socially embedded actions such as imitation and interpersonal synchrony facilitates relationships with peers and caregivers. Imitation and interpersonal synchrony impairments of children with Autism Spectrum Disorder (ASD) might contribute to their difficulties in connecting and learning from others. Previous fMRI studies investigated cortical activation in children with ASD during finger/hand movement imitation; however, we do not know whether these findings generalize to naturalistic face-to-face imitation/interpersonal synchrony tasks. Using functional near infrared spectroscopy (fNIRS), the current study assessed the cortical activation of children with and without ASD during a face-to-face interpersonal synchrony task. Fourteen children with ASD and 17 typically developing (TD) children completed three conditions: a) Watch-observed an adult clean up blocks; b) Do-cleaned up the blocks on their own; and c) Together-synchronized their block clean up actions to that of an adult. Children with ASD showed lower spatial and temporal synchrony accuracies but intact motor accuracy during the Together/interpersonal synchrony condition. In terms of cortical activation, children with ASD had hypoactivation in the middle and inferior frontal gyri (MIFG) as well as middle and superior temporal gyri (MSTG) while showing hyperactivation in the inferior parietal cortices/lobule (IPL) compared to the TD children. During the Together condition, the TD children showed bilaterally symmetrical activation whereas children with ASD showed more left-lateralized activation over MIFG and right-lateralized activation over MSTG. Additionally, using ADOS scores, in children with ASD greater social affect impairment was associated with lower activation in the left MIFG and more repetitive behavior impairment was associated with greater activation over bilateral MSTG. In children with ASD better communication performance on the VABS was associated with greater MIFG and/or MSTG activation. We identified objective neural biomarkers that could be utilized as outcome predictors or treatment response indicators in future intervention studies.

Ordered interpersonal synchronisation in ASD children via robots

Children with autistic spectrum disorders (ASD) experience persistent disrupted coordination in interpersonal synchronisation that is thought to be associated with deficits in neural connectivity. Robotic interventions have been explored for use with ASD children worldwide revealing that robots encourage one-to-one social and emotional interactions. However, associations between interpersonal synchronisation and emotional empathy have not yet been directly explored in French and Japanese ASD children when they interact with a human or a robot under analogous experimental conditions. Using the paradigm of actor-perceiver, where the child was the actor and the robot or the human the perceiver, we recorded the autonomic heart rate activation and reported emotional feelings of ASD children in both countries. Japanese and French ASD children showed different interpersonal synchronisation when they interacted with the human perceiver, even though the human was the same in both countries. However, they exhibited similar interpersonal synchronisation when the perceiver was the robot. The findings suggest that the mechanism combining interpersonal synchronisation and emotional empathy might be weakened but not absent in ASD children and that both French and Japanese ASD children do spontaneously and unconsciously discern non verbal actions of non human partners through a direct matching process that occurs via automatic mapping.

Brain-to-Brain Neural Synchrony During Social Interactions: A Systematic Review on Hyperscanning Studies

The aim of this study was to conduct a comprehensive review on hyperscanning research (measuring brain activity simultaneously from more than two people interacting) using an explicit systematic method, the preferred reporting items for systematic reviews and meta-analyses (PRISMA). Data were searched from IEEE Xplore, PubMed, Engineering Village, Web of Science and Scopus databases. Inclusion criteria were journal articles written in English from 2000 to 19 June 2019. A total of 126 empirical studies were screened out to address three specific questions regarding the neuroimaging method, the application domain, and the experiment paradigm. Results showed that the most used neuroimaging method with hyperscanning was magnetoencephalography/electroencephalography (MEG/EEG; 47%), and the least used neuroimaging method was hyper-transcranial Alternating Current Stimulation (tACS) (1%). Applications in cognition accounted for almost half the studies (48%), while educational applications accounted for less than 5% of the studies. Applications in decision-making tasks were the second most common (26%), shortly followed by applications in motor synchronization (23%). The findings from this systematic review that were based on documented, transparent and reproducible searches should help build cumulative knowledge and guide future research regarding inter-brain neural synchrony during social interactions, that is, hyperscanning research.

Coordination Dynamics: A Foundation for Understanding Social Behavior

Humans' interactions with each other or with socially competent machines exhibit lawful coordination patterns at multiple levels of description. According to Coordination Dynamics, such laws specify the flow of coordination states produced by functional synergies of elements (e.g., cells, body parts, brain areas, people…) that are temporarily organized as single, coherent units. These coordinative structures or synergies may be mathematically characterized as informationally coupled self-organizing dynamical systems (Coordination Dynamics). In this paper, we start from a simple foundation, an elemental model system for social interactions, whose behavior has been captured in the Haken-Kelso-Bunz (HKB) model. We follow a tried and tested scientific method that tightly interweaves experimental neurobehavioral studies and mathematical models. We use this method to further develop a body of empirical research that advances the theory toward more generalized forms. In concordance with this interdisciplinary spirit, the present paper is written both as an overview of relevant advances and as an introduction to its mathematical underpinnings. We demonstrate HKB's evolution in the context of social coordination along several directions, with its applicability growing to increasingly complex scenarios. In particular, we show that accommodating for symmetry breaking in intrinsic dynamics and coupling, multiscale generalization and adaptation are principal evolutions. We conclude that a general framework for social coordination dynamics is on the horizon, in which models support experiments with hypothesis generation and mechanistic insights.

What's in a Moment: What Can Be Learned About Pair Bonding From Studying Moment-To-Moment Behavioral Synchrony Between Partners?

Our understanding of the behavioral and physiological mechanisms of monogamy largely comes from studies of behavioral interactions unique to pair-bonded individuals. By focusing on these highly marked behaviors, a remarkable conservation in the mechanisms underlying pair bonding has been revealed; however, we continue to know very little about the range of behavioral and neurobiological mechanisms that could explain the great diversity of pair-bonding phenotypes that exists both within and across species. In order to capture the dynamic nature of bonds over time and across contexts, we need specific, operationally-defined behavioral variables relevant across such a diversity of scenarios. Additionally, we need to be able to situate these behavioral variables within broader frameworks that allow us to interpret and compare patterns seen across species. Here I review what is known about behavioral synchrony with respect to pair bonding and discuss using synchrony as such a variable as well as a framework to expand on our understanding of pair bonding across timescales, contexts and species. First, I discuss the importance of behavioral synchrony and parental coordination for reproductive success in monogamous biparental bird species. Second, I highlight research documenting the critical importance of interpersonal coordination for human social relationships. Finally, I present recent work that experimentally bridges these lines of research by quantifying moment-to-moment behavioral synchrony during brief social interactions in zebra finch dyads. All together, these distinct perspectives support the notion that synchrony (1) is a shared premise for sociality across species, (2) is deeply shaped by social experiences, and (3) exists across timescales, behaviors, and levels of physiology. Conceptualizing pair bonding through the framework of behavioral synchrony is likely to facilitate a deeper understanding of the nuances of how social experiences and interactions impact the brain and behavior.

Keeping in Touch with Mental Health: The Orienting Reflex and Behavioral Outcomes from Calatonia

Physical and psychological therapy based on touch has been gradually integrated into broader mental health settings in the past two decades, evolving from a variety of psychodynamic, neurobiological and trauma-based approaches, as well as Eastern and spiritual philosophies and other integrative and converging systems. Nevertheless, with the exception of a limited number of well-known massage therapy techniques, only a few structured protocols of touch therapy have been standardized and researched to date. This article describes a well-defined protocol of touch therapy in the context of psychotherapy-the Calatonia technique-which engages the orienting reflex. The orienting reflex hypothesis is explored here as one of the elements of this technique that helps to decrease states of hypervigilance and chronic startle reactivity (startle and defensive reflexes) and restore positive motivational and appetitive states.

Social Allostasis and Social Allostatic Load: A New Model for Research in Social Dynamics, Stress, and Health

Theories such as social baseline theory have argued that social groups serve a regulatory function but have not explored whether this regulatory process carries costs for the group. Allostatic load, the wear and tear on regulatory systems caused by chronic or frequent stress, is marked by diminished stress system flexibility and compromised recovery. We argue that allostatic load may develop within social groups as well and provide a model for how relationship dysfunction operates. Social allostatic load may be characterized by processes such as groups becoming locked into static patterns of interaction and may ultimately lead to up-regulation or down-regulation of a group's set point, or the optimal range of arousal or affect around which the group tends to converge. Many studies of emotional and physiological linkage within groups have reported that highly correlated states of arousal, which may reflect failure to maintain a group-level regulatory baseline, occur in the context of stress, conflict, and relationship distress. Relationship strain may also place greater demands on neurocognitive regulatory processes. Just as allostatic load may be detrimental to individual health, social allostatic load may corrode relationship quality.

Prior physical synchrony enhances rapport and inter-brain synchronization during subsequent educational communication

Physical synchrony has been suggested to have positive effects on not only concurrent but also subsequent communication, but the underlying neural processes are unclear. Using functional near-infrared spectroscopy (fNIRS) hyperscanning, we tested the effects of preceding physical synchrony on subsequent dyadic teaching-learning communication. Thirty-two pairs of participants performed two experimental sessions. In each session, they underwent a rhythmic arm movement block with synchronous or asynchronous conditions, and then taught/learned unknown words to/from each other according to a given scenario. Neural activities in their medial and left lateral prefrontal cortex (PFC) were measured and inter-brain synchronization (IBS) during the teaching-learning blocks was evaluated. Participants rated their subjective rapport during the teaching-learning blocks, and took a word memory test. The analyses revealed that (1) prior physical synchrony enhanced teacher-learner rapport; (2) prior physical synchrony also enhanced IBS in the lateral PFC; and (3) IBS changes correlated positively with rapport changes. Physical synchrony did however not affect word memory performance. These results suggest that IBS can be useful to measure the effects of social-bonding facilitation activities for educational communication.

Empathic perspective taking promotes interpersonal coordination through music

Coordinated behavior promotes collaboration among humans. To shed light upon this relationship, we investigated whether and how interpersonal coordination is promoted by empathic perspective taking (EPT). In a joint music-making task, pairs of participants rotated electronic music-boxes, producing two streams of musical sounds that were meant to be played synchronously. Participants – who were not musically trained – were assigned to high and low EPT groups based on pre-experimental assessments using a standardized personality questionnaire. Results indicated that high EPT pairs were generally more accurate in synchronizing their actions. When instructed to lead the interaction, high and low EPT leaders were equally cooperative with followers, making their performance tempo more regular, presumably in order to increase their predictability and help followers to synchronize. Crucially, however, high EPT followers were better able to use this information to predict leaders’ behavior and thus improve interpersonal synchronization. Thus, empathic perspective taking promotes interpersonal coordination by enhancing accuracy in predicting others’ behavior while leaving the aptitude for cooperation unaltered. We argue that such predictive capacity relies on a sensorimotor mechanism responsible for simulating others’ actions in an anticipatory manner, leading to behavioral advantages that may impact social cognition on a broad scale.

Observing Synchrony in Dyads

Abstract. This research tested whether observing members of a dyad behave in synchrony influences observers’ expectations and intentions about that dyad. In four studies, participants observed a dyad move in synchrony and were asked to make inferences about them. Results suggest that interpersonal synchrony serves as a social cue, such that observers expect the members of the dyad to work well together. Moreover, synchrony makes observers more likely to want to affiliate with the dyad. These findings shed light on how the social function of synchrony extends beyond the people who experience it to those who observe it.

Emotional Empathy as a Mechanism of Synchronisation in Child-Robot Interaction

Simulating emotional experience, emotional empathy is the fundamental ingredient of interpersonal communication. In the speaker-listener scenario, the speaker is always a child, the listener is a human or a toy robot. Two groups of neurotypical children aged 6 years on average composed the population: one Japanese (n = 20) and one French (n = 20). Revealing potential similarities in communicative exchanges in both groups when in contact with a human or a toy robot, the results might signify that emotional empathy requires the implication of an automatic identification. In this sense, emotional empathy might be considered a broad idiosyncrasy, a kind of synchronisation, offering the mind a peculiar form of communication. Our findings seem to be consistent with the assumption that children's brains would be constructed to simulate the feelings of others in order to ensure interpersonal synchronisation.

Dynamics of Simultaneous and Imitative Bodily Coordination in Trust and Distrust

Body synchronization between interacting people involves coordinative movements in time, space and form. The introduction of newer technologies for automated video analysis and motion tracking has considerably improved the accurate measurement of coordination, particularly in temporal and spatial terms. However, the form of interpersonal coordination has been less explored. In the present study we address this gap by exploring the effect of trust on temporal and morphological patterns of interpersonal coordination. We adapted an optical motion-capture system to record spontaneous body movements in pairs of individuals engaged in natural conversations. We conducted two experiments in which we manipulated trust through a breach of expectancy (Study 1: 10 trustful and 10 distrustful participants) and friendship (Study 2: 20 dyads of friends and 20 dyads of strangers). In Study 1, results show the participants' strong, early mirror-like coordination in response to the confederates' breach of trust. In Study 2, imitative coordination tended to be more pronounced in pairs of friends than in pairs of non-friends. Overall, our results show not only that listeners move in reaction to speakers, but also that speakers react to listeners with a chain of dynamic coordination patterns affected by the immediate disposition of, and long-term relationship with, their interlocutors.

Oxytocin facilitates reciprocity in social communication

Synchrony in social groups may confer significant evolutionary advantages by improving group cohesion and social interaction. However, the neurobiological mechanisms translating social synchrony into refined social information transmission between interacting individuals are still elusive. In two successively conducted experiments involving a total of 306 healthy volunteers, we explored the involvement of the neuropeptide oxytocin (OXT) in reciprocal social interaction. First, we show that synchronous social interactions evoke heightened endogenous OXT release in dyadic partners. In a second step, we examined the consequences of elevated OXT concentrations on emotion transmission by intranasally administering synthetic OXT before recording emotional expressions. Intriguingly, our data demonstrate that the subjects’ facial and vocal expressiveness of fear and happiness is enhanced after OXT compared with placebo administration. Collectively, our findings point to a central role of social synchrony in facilitating reciprocal communication between individuals via heightened OXT signaling. Elevated OXT concentrations among synchronized individuals seem to augment the partners’ emotional expressiveness, thereby contributing to improved transmission of emotional information in social communication.

Embodied Cognition and the Direct Induction of Affect as a Compliment to Cognitive Behavioural Therapy

We make the case for the possible integration of affect experience induced via embodiment techniques with CBT for the treatment of emotional disorders in clinical settings. Theoretically we propose a possible integration of cognitive behavioural theory, neuroscience, embodied cognition and important processes of client change outcomes such as the therapeutic alliance to enhance client outcomes. We draw from evidence of bidirectional effects between embodiment modes of bottom-up (sensory-motor simulations giving rise to important basis of knowledge) and top-down (abstract mental representations of knowledge) processes such as CBT in psychotherapy. The paper first describes the dominance and success of CBT for the treatment of a wide range of clinical disorders. Some limitations of CBT, particularly for depression are also outlined. There is a growing body of evidence for the added value of experiential affect-focused interventions combined with CBT. Evidence for the embodied model of cognition and emotion is reviewed. Advantages of embodiment is highlighted as a complimentary process model to deepen the intensity and valence of affective experience. It is suggested that an integrated embodiment approach with CBT enhances outcomes across a wide range of emotional disorders. A description of our embodiment method integrated with CBT for inducing affective experience, emotional regulation, acceptance of unwanted emotions and emotional mastery is given. Finally, the paper highlights the importance of the therapeutic alliance as a critical component of the change process. The paper ends with a case study highlighting some clinical strategies that may aid the therapist to integrate embodiment techniques in CBT that can further explore in future research on affective experience in CBT for a wider range of clinical disorders.

I Am There … but Not Quite: An Unfaithful Mirror That Reduces Feelings of Ownership and Agency

The experience of seeing one's own face in a mirror is a common experience in daily life. Visual feedback from a mirror is linked to a sense of identity. We developed a procedure that allowed individuals to watch their own face, as in a normal mirror, or with specific distortions (lag) for active movement or passive touch. By distorting visual feedback while the face is being observed on a screen, we document an illusion of reduced embodiment. Participants made mouth movements, while their forehead was touched with a pen. Visual feedback was either synchronous (simultaneous) with reality, as in a mirror, or asynchronous (delayed). Asynchronous feedback was exclusive to touch or movement in different conditions and incorporated both in a third condition. Following stimulation, participants rated their perception of the face in the mirror, and perception of their own face, on questions that tapped into agency and ownership. Results showed that perceptions of both agency and ownership were affected by asynchrony. Effects related to agency, in particular, were moderated by individual differences in depersonalisation and auditory hallucination-proneness, variables with theoretical links to embodiment. The illusion presents a new way of investigating the extent to which body representations are malleable.

Interpersonal Coordination: Methods, Achievements, and Challenges

Research regarding interpersonal coordination can be traced back to the early 1960s when video recording began to be utilized in communication studies. Since then, technological advances have extended the range of techniques that can be used to accurately study interactional phenomena. Although such a diversity of methods contributes to the improvement of knowledge concerning interpersonal coordination, it has become increasingly difficult to maintain a comprehensive view of the field. In the present article, we review the main capture methods by describing their major findings, levels of description and limitations. We group them into three categories: video analysis, motion tracking, and psychophysiological and neurophysiological techniques. Revised evidence suggests that interpersonal coordination encompasses a family of morphological and temporal synchronies at different levels and that it is closely related to the construction and maintenance of a common social and affective space. We conclude by arguing that future research should address methodological challenges to advance the understanding of coordination phenomena.

Persuasion, Influence, and Value: Perspectives from Communication and Social Neuroscience

Opportunities to persuade and be persuaded are ubiquitous. What determines whether influence spreads and takes hold? This review provides an overview of evidence for the central role of subjective valuation in persuasion and social influence for both propagators and receivers of influence. We first review evidence that decisions to communicate information are determined by the subjective value a communicator expects to gain from sharing. We next review evidence that the effects of social influence and persuasion on receivers, in turn, arise from changes in the receiver's subjective valuation of objects, ideas, and behaviors. We then review evidence that self-related and social considerations are two key inputs to the value calculation in both communicators and receivers. Finally, we highlight biological coupling between communicators and receivers as a mechanism through which perceptions of value can be transmitted.

Physiological dynamics of stress contagion

Can viewing others experiencing stress create a “contagious” physiological stress response in the observer? To investigate second-hand stress, we first created a stimulus set of videos, which featured participants speaking under either minimal stress, high stress, or while recovering from stress. We then recruited a second set of participants to watch these videos. All participants (speakers and observers) were monitored via electrocardiogram. Cardiac activity of the observers while watching the videos was then analyzed and compared to that of the speakers. Furthermore, we assessed dispositional levels of empathy in observers to determine how empathy might be related to the degree of stress contagion. Results revealed that depending on the video being viewed, observers experienced differential changes in cardiac activity that were based on the speaker’s stress level. Additionally, this is the first demonstration that individuals high in dispositional empathy experience these physiological changes more quickly.

Oxytocin improves synchronisation in leader-follower interaction

The neuropeptide oxytocin has been shown to affect social interaction. Meanwhile, the underlying mechanism remains highly debated. Using an interpersonal finger-tapping paradigm, we investigated whether oxytocin affects the ability to synchronise with and adapt to the behaviour of others. Dyads received either oxytocin or a non-active placebo, intranasally. We show that in conditions where one dyad-member was tapping to another unresponsive dyad-member – i.e. one was following another who was leading/self-pacing – dyads given oxytocin were more synchronised than dyads given placebo. However, there was no effect when following a regular metronome or when both tappers were mutually adapting to each other. Furthermore, relative to their self-paced tapping partners, oxytocin followers were less variable than placebo followers. Our data suggests that oxytocin improves synchronisation to an unresponsive partner’s behaviour through a reduction in tapping-variability. Hence, oxytocin may facilitate social interaction by enhancing sensorimotor predictions supporting interpersonal synchronisation. The study thus provides novel perspectives on how neurobiological processes relate to socio-psychological behaviour and contributes to the growing evidence that synchronisation and prediction are central to social cognition.

Prosocial Consequences of Interpersonal Synchrony: A Meta-Analysis

Abstract. The capacity to establish interpersonal synchrony is fundamental to human beings because it constitutes the basis for social connection and understanding. Interpersonal synchrony refers to instances when the movements or sensations of two or more people overlap in time and form. Recently, the causal influence of interpersonal synchrony on prosociality has been established through experiments. The current meta-analysis is the first to synthesize these isolated and sometimes contradictory experiments. We meta-analyzed 60 published and unpublished experiments that compared an interpersonal synchrony condition with at least one control condition. The results reveal a medium effect of interpersonal synchrony on prosociality with regard to both attitudes and behaviors. Furthermore, experimenter effects and intentionality moderate these effects. We discuss the strengths and limitations of our analysis, as well as its practical implications, and we suggest avenues for future research.