Coordinating bodies and minds: Behavioral synchrony fosters mentalizing

Empathic Behavior and Behavioral Synchrony During Video Conversations in Autistic and Non-autistic Adolescents

Behavioral synchrony is an important component of successful social interaction. Synchronization of facial expressions during interaction is considered a facilitator of empathic behavior. Autistic individuals show alterations in synchronous and empathic behaviors. Yet, an ecological examination of these among adolescents is needed. Through a video-based platform, we employed a social interaction sequence with a nonautistic confederate that included a friendly conversation and an expression of discouragement. 50 male adolescents (23 autistic) participated. Socio-emotional behaviors, assessed by naïve trained raters and by automated measure of facial expressions, were analyzed. Results indicated reduced synchrony in interactions with autistic adolescents, compared to non-autistic adolescents, as well as fewer empathic behaviors. Participants' emotion recognition abilities did not account for these differences. Our findings point to the central role of behavioral synchrony in the social disparities autistic adolescents often experience.

Actions and feelings in sync: exploring the relationship between synchrony and empathy in children's dyadic musical interactions

Introduction

This study investigated the relationship between interpersonal synchrony and empathy in children's music-making. Drawing from a theoretical framework that suggests a bidirectional relationship between synchrony and empathy, the study examined three key aspects of this relationship: (1) the role of children's trait empathy in achieving interpersonal synchrony; (2) synchrony's effects on empathy following brief musical interactions; and (3) the role of experimentally induced empathy in moderating the social bonding effects of synchrony.

Methods

Seventy-two pairs of primary school children participated in two experiments. The first involved free tapping, where participants were instructed to synchronize with one another. In the second experiment, synchrony was manipulated, using an apparatus that either facilitated or disrupted synchrony within pairs. Prior to this task, half of the pairs received a false message about their partner, intended to induce empathy. Trait empathy and social bonding were assessed via self-reported questionnaires.

Results

Findings revealed that cognitive and affective trait empathy related to children's ability to synchronize with one another, particularly when participants' temporal performance was unstable (Aspect 1). In addition, brief synchronous musical interactions were found to promote empathy within pairs (Aspect 2). Our method to experimentally induce empathy was not sufficient to influence the social bonding effects of synchrony (Aspect 3). However, trait empathy, pairs' gender composition and familiarity between children emerged as factors affecting the attainment of synchrony and the bonding experience of music-making.

Discussion

This is the first empirical study investigating multiple aspects of the interplay between synchronizing and empathizing in children, paving the way for future exploration of the mechanisms allowing for a bidirectional relationship. The study outcomes can inform musical interventions leveraging this relationship to nurture children's simultaneous musical and social development.

Synchrony Across Brains

Second-person neuroscience focuses on studying the behavioral and neuronal mechanisms of real-time social interactions within single and across interacting brains. In this review article, we describe the developments that have been undertaken to study socially interactive phenomena and the behavioral and neurobiological processes that extend across interaction partners. More specifically, we focus on the role that synchrony across brains plays in enabling and facilitating social interaction and communication and in shaping social coordination and learning, and we consider how reduced synchrony across brains may constitute a core feature of psychopathology.

Client-counselor behavioral and inter-brain synchronization among dismissing and secure clients and its association with alliance quality and outcome

Objective This study aimed to explore whether behavioral synchrony (BS) and inter-brain synchrony (IBS) could serve as potential biomarkers for alliance quality or outcomes among clients with different adult attachment styles. Method: We assessed the clients' self-report working alliance and clinical outcomes as well as simultaneously measured BS using motion energy analysis (MEA) and IBS with functional near-infrared spectroscopy (fNIRS) among 37 secure (N = 21) or dismissing (N = 16) clients with their counselors during the first psychological counseling meeting. Results: Dismissing dyads manifested significantly higher late-stage counselor-led and client-led IBS (p = .018) than secure dyads. Adult attachment style served as the moderators in the correlation of both whole-stage client-led BS with bond dimension of alliance (p = .015) as well as in the correlation of both whole-stage no-lag IBS with CORE-10 score changes (p = .022). Moreover, increases in the whole-stage client-led BS were significantly associated with decreases in early-stage, late-stage and whole-stage no-lag IBS (all ps ≤ 0.01). Conclusion: These findings revealed the potentially impeding role of interpersonal synchrony in alliance quality for dismissing clients, at least during the first psychological counseling meetings. They also might partially validate the relationship between different modalities of interpersonal synchrony.

Three roots of online toxicity: disembodiment, accountability, and disinhibition

Online communication is central to modern social life, yet it is often linked to toxic manifestations and reduced well-being. How and why online communication enables these toxic social effects remains unanswered. In this opinion, we propose three roots of online toxicity: disembodiment, limited accountability, and disinhibition. We suggest that virtual disembodiment results in a chain of psychological states primed for deleterious social interaction. Drawing from differences between face-to-face and online interactions, the framework highlights and addresses the fundamental problems that result in impaired communication between individuals and explicates its effects on social toxicity online.

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.

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.

Social and nonlinear dynamics unite: musical group synchrony

Synchronization, the human tendency to align behaviors in time with others, is necessary for many survival skills. The ability to synchronize actions with rhythmic (predictable) sound patterns is especially well developed in music making. Recent models of synchrony in musical ensembles rely on pairwise comparisons between group members. This pairwise approach to synchrony has hampered theory development, given current findings from social dynamics indicating shifts in members' influence within larger groups. We draw on social theory and nonlinear dynamics to argue that emergent properties and novel roles arise in musical group synchrony that differ from individual or pairwise behaviors. This transformational shift in defining synchrony sheds light on successful outcomes as well as on disruptions that cause negative behavioral outcomes.

Musical coordination affects children's perspective-taking, but musical synchrony does not

Perspective-taking, which is important for communication and social activities, can be cultivated through joint actions, including musical activities in children. We examined how rhythmic activities requiring coordination affect perspective-taking in a referential communication task with 100 Chinese 4- to 6-year-old children. In Study 1, 5- to 6-year-old children played an instrument with a virtual partner in one of three coordination conditions: synchrony, asynchrony, and antiphase synchrony. Eye movements were then monitored with the partner giving instructions to identify a shape referent which included a pre-nominal scalar adjective (e.g., big cubic block). When the target contrast (a small cubic block) was in the shared ground and a competitor contrast was occluded for the partner, participants who used perspective differences could, in principle, identify the intended referent before the shape was named. We hypothesized that asynchronous and antiphase synchronous musical activities, which require self-other distinction, might have stronger effects on perspective-taking than synchronous activity. Children in the asynchrony and antiphase synchrony conditions, but not the synchrony condition, showed anticipatory looks at the target, demonstrating real-time use of the partner's perspective. Study 2 was conducted to determine if asynchrony and antiphase asynchrony resulted in perspective-taking that otherwise would not have been observed, or if synchronous coordination inhibited perspective-taking that would otherwise have occurred. We found no evidence for online perspective-taking in 4- to 6-year-old children without music manipulation. Therefore, playing instruments asynchronously or in alternation, but not synchronously, increases perspective-taking in children of this age, likely by training self-other distinction and control. A video abstract of this article can be viewed at https://youtu.be/TM9h_GpFlsA. RESEARCH HIGHLIGHTS: This study is the first to show that rhythmic coordination, a form of non-linguistic interaction, can affect children's performance in a subsequent linguistic task. Eye-movement data revealed that children's perspective-taking in language processing was facilitated by prior asynchronous and antiphase synchronous musical interactions, but not by synchronous coordination. The results challenge the common "similar is better" view, suggesting that maintaining self-other distinction may benefit social interactions that involve representing individual differences.

Multimodal Approach for Characterizing the Quality of Parent-Child Interaction: A Single Synchronization Source May Not Tell the Whole Story

The interaction between the parent and child is essential for the child's cognitive and emotional development and sets the path for future well-being. These interactions, starting from birth, are necessary for providing the sensory stimulation the child needs in the critical time window of brain development. The characterization of parent-child interactions is traditionally performed by human decoding. This approach is considered the leading and most accurate way of characterizing the quality of these interactions. However, the development of computational tools and especially the concept of parent-child synchronization opened up an additional source of data characterizing these interactions in an objective, less human-labor manner. Such sources include brain-to-brain, voice/speech, eye contact, motor, and heart-rate synchronization. However, can a single source synchronization dataset accurately represent parent-child interaction? Will attending to the same stimulation, often resulting in a higher brain-to-brain synchronization, be considered an interactive condition? In this perspective, we will try to convey a new concept of the child-parent interaction synchronization (CHIPS) matrix, which includes the different sources of signals generated during an interaction. Such a model may assist in explaining the source of interaction alterations in the case of child/parent developmental/emotional or sensory deficits and may open up new ways of assessing interventions and changes in parent-child interactions along development. We will discuss this interaction during one of the parent-child joint activities providing opportunities for interaction, i.e., storytelling.

Shared neural representations and temporal segmentation of political content predict ideological similarity

Despite receiving the same sensory input, opposing partisans often interpret political content in disparate ways. Jointly analyzing controlled and naturalistic functional magnetic resonance imaging data, we uncover the neurobiological mechanisms explaining how these divergent political viewpoints arise. Individuals who share an ideology have more similar neural representations of political words, experience greater neural synchrony during naturalistic political content, and temporally segment real-world information into the same meaningful units. In the striatum and amygdala, increasing intersubject similarity in neural representations of political concepts during a word reading task predicts enhanced synchronization of blood oxygen level-dependent time courses when viewing real-time, inflammatory political videos, revealing that polarization can arise from differences in the brain's affective valuations of political concepts. Together, this research shows that political ideology is shaped by semantic representations of political concepts processed in an environment free of any polarizing agenda and that these representations bias how real-world political information is construed into a polarized perspective.

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.

Agency and Identity in the Collective Self

Contemporary research on human sociality is heavily influenced by the social identity approach, positioning social categorization as the primary mechanism governing social life. Building on the distinction between agency and identity in the individual self ("I" vs. "Me"), we emphasize the analogous importance of distinguishing collective agency from collective identity ("We" vs. "Us"). While collective identity is anchored in the unique characteristics of group members, collective agency involves the adoption of a shared subjectivity that is directed toward some object of our attention, desire, emotion, belief, or action. These distinct components of the collective self are differentiated in terms of their mental representations, neurocognitive underpinnings, conditions of emergence, mechanisms of social convergence, and functional consequences. Overall, we show that collective agency provides a useful complement to the social categorization approach, with unique implications for multiple domains of human social life, including collective action, responsibility, dignity, violence, dominance, ritual, and morality.

The Mirroring Dance: Synchrony and Interaction Quality of Five Adolescents and Adults on the Autism Spectrum in Dance/Movement Therapy

Background: Individuals on the autism spectrum are often described as having atypical social interactions. Ideally, interactional synchrony helps any interaction flow smoothly with each individual responding verbally, non-verbally, and/or emotionally within a short timeframe. Differences in interactional synchrony may impact how individuals on the autism spectrum experience social encounters. Method: This mixed methods pilot study examined interactional synchrony in five cases of adolescents and adults on the autism spectrum through secondary analysis of video of the participants in movement-based mirroring tasks during dance/movement therapy. Raters described the movement and interactions of the participants while they were leading and following mirroring and engaged in open-ended free dances with a partner. Videos were also scored on measures of affective engagement, flow of the interaction, and synchrony. Results: One of the most striking findings of this study was the difference between engagement in the instructions of the task and engagement with the partner: participants often followed the instructions for the mirroring tasks with little further social engagement with their partner. When participants did engage in moments of social initiation, attunement to the partner, and interactive behaviors, these did not develop into longer interactions. A paired t-test of the correlation coefficients for each participant showed that scores on synchrony and affective engagement were more strongly positively correlated in the less structured open-ended dance and in video clips of interactive behaviors, than in the videos of simply leading or following mirroring. Synchrony was also significantly more strongly positively correlated with the observed flow of the interaction than with observed affective engagement. With the small sample size, however, most of the correlation coefficients were not significant and should be tested on a larger sample. Discussion: Interpersonal synchrony may not be sufficient to effectively support social engagement when individuals on the autism spectrum simply follow instructions to synchronize their movements. Synchrony-based interventions may therefore need to include more complex open-ended social scenarios as interactional synchrony may then be more correlated with perceived interaction quality. Therapists may also need to partner with participants to model using non-verbal social behaviors to develop interactions within mirroring tasks.

Shifts in Behavioral Synchrony in Response to an Interaction Partner's Distress in Adolescents With and Without ASD

Individuals with Autism spectrum disorder (ASD) show altered behavioral synchrony and empathic behavior. Yet, an ecologically valid examination of these in adolescents is still required. We employed a social interaction sequence comprising a friendly conversation with a confederate, an expression of distress by her, and a return to friendly conversation. 44 male adolescents (22 with ASD) participated. Socio-emotional behaviors, coded by blind raters and through automated analyses of motion, were analyzed. Results indicated reduced synchrony in the ASD group. Moreover, whereas controls displayed a decrease in synchrony when facing another's distress, adolescents with ASD showed no such change. No group differences were found on empathic behavior. Findings imply gaps between verbal and non-verbal responses of adolescents with ASD to a distressed interaction partner.

Slow update of internal representations impedes synchronization in autism

Autism is a neurodevelopmental disorder characterized by impaired social skills, motor and perceptual atypicalities. These difficulties were explained within the Bayesian framework as either reflecting oversensitivity to prediction errors or - just the opposite - slow updating of such errors. To test these opposing theories, we administer paced finger-tapping, a synchronization task that requires use of recent sensory information for fast error-correction. We use computational modelling to disentangle the contributions of error-correction from that of noise in keeping temporal intervals, and in executing motor responses. To assess the specificity of tapping characteristics to autism, we compare performance to both neurotypical individuals and individuals with dyslexia. Only the autism group shows poor sensorimotor synchronization. Trial-by-trial modelling reveals typical noise levels in interval representations and motor responses. However, rate of error correction is reduced in autism, impeding synchronization ability. These results provide evidence for slow updating of internal representations in autism.

The Potential Role of Dopamine in Mediating Motor Function and Interpersonal Synchrony

Motor functions in general and motor planning in particular are crucial for our ability to synchronize our movements with those of others. To date, these co-occurring functions have been studied separately, and as yet it is unclear whether they share a common biological mechanism. Here, we synthesize disparate recent findings on motor functioning and interpersonal synchrony and propose that these two functions share a common neurobiological mechanism and adhere to the same principles of predictive coding. Critically, we describe the pivotal role of the dopaminergic system in modulating these two distinct functions. We present attention deficit hyperactivity disorder (ADHD) as an example of a disorder that involves the dopaminergic system and describe deficits in motor and interpersonal synchrony. Finally, we suggest possible directions for future studies emphasizing the role of dopamine modulation as a link between social and motor functioning.

Speaking out of turn: How video conferencing reduces vocal synchrony and collective intelligence

Collective intelligence (CI) is the ability of a group to solve a wide range of problems. Synchrony in nonverbal cues is critically important to the development of CI; however, extant findings are mostly based on studies conducted face-to-face. Given how much collaboration takes place via the internet, does nonverbal synchrony still matter and can it be achieved when collaborators are physically separated? Here, we hypothesize and test the effect of nonverbal synchrony on CI that develops through visual and audio cues in physically-separated teammates. We show that, contrary to popular belief, the presence of visual cues surprisingly has no effect on CI; furthermore, teams without visual cues are more successful in synchronizing their vocal cues and speaking turns, and when they do so, they have higher CI. Our findings show that nonverbal synchrony is important in distributed collaboration and call into question the necessity of video support.

Leadership and tempo perturbation affect coordination in medium-sized groups

In marching bands, sports, dance and virtually all human group behaviour, we coordinate our actions with others. Coordinating actions in time and space can act as a social glue, facilitating bonding among people. However, much of our understanding about coordination dynamics is based on research into dyadic interactions. Little is known about the nature of the sensorimotor underpinnings and social bonding outcomes of coordination in medium-sized groups-the type of groups, in which most everyday teamwork takes place. In this study, we explored how the presence of a leader and an unexpected perturbation influence coordination and cohesion in a naturalistic setting. In groups of seven, participants were instructed to walk in time to an auditory pacing signal. We found that the presence of a reliable leader enhanced coordination with the target tempo, which was disrupted when the leader abruptly changed their movement tempo. This effect was not observed on coordination with the group members. Moreover, participants' perceptions of being a follower and group cooperativeness increased in the presence of a leader. This study extends our knowledge about coordination beyond previous work on dyads. We discuss our results in light of sensorimotor coupling and social cohesion theories of coordination in groups.

Intentional synchronisation affects automatic imitation and source memory

Acting in synchrony is a fundamental part of many social interactions and can have pro-social consequences. Explanations for this relationship were investigated here using implicit measures of imitation (automatic imitation task) and memory (preference overlap task). In Study 1, participants performed an intentional synchronisation task where they moved sliders in or out of time with another person while a third person observed. Those who had moved in synchrony showed a stronger tendency to imitate their partner’s actions than those who had moved in a non-synchronous way. Similarly, coordinated partners were also more likely to share object preferences. Results also showed that rather than memory blurring between co-actors, participants had improved memories for the self. Study 2 exchanged intentional for incidental coordination (coordinating with a synchronous metronome). None of the findings from Study 1 replicated when synchronisation was incidental rather than intentional, suggesting that having a shared goal may be critical for triggering effects of synchronisation on imitation tendencies and memory. Together these findings favour explanations related to changes in social categorisation over representational overlap between co-actors.

Impairments of interpersonal synchrony evident in attention deficit hyperactivity disorder (ADHD)

In addition to well-known attention deficiencies, attention deficit hyperactivity disorder (ADHD) is accompanied by deficiencies in social cognition. Both intentional and spontaneous interpersonal synchrony have been found to be an essential part of successful human interaction. Here, we used a novel paradigm to assess intentional and spontaneous interpersonal synchrony in adults with and without ADHD. Our data indicate that intentional interpersonal synchrony is reduced in ADHD, whereas spontaneous interpersonal synchrony remains intact. These results suggest that a dysfunctional pattern of interpersonal synchrony may account for interpersonal difficulties in ADHD.

The cultural evolutionary trade-off of ritualistic synchrony

From Australia to the Arctic, human groups engage in synchronous behaviour during communal rituals. Because ritualistic synchrony is widespread, many argue that it is functional for human groups, encouraging large-scale cooperation and group cohesion. Here, we offer a more nuanced perspective on synchrony's function. We review research on synchrony's prosocial effects, but also discuss synchrony's antisocial effects such as encouraging group conflict, decreasing group creativity and increasing harmful obedience. We further argue that a tightness-looseness (TL) framework helps to explain this trade-off and generates new predictions for how ritualistic synchrony should evolve over time, where it should be most prevalent, and how it should affect group well-being. We close by arguing that synthesizing the literature on TL with the literature on synchrony has promise for understanding synchrony's role in a broader cultural evolutionary framework. This article is part of the theme issue 'Ritual renaissance: new insights into the most human of behaviours'.

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.

A New Unifying Account of the Roles of Neuronal Entrainment

Rhythms are a fundamental and defining feature of neuronal activity in animals including humans. This rhythmic brain activity interacts in complex ways with rhythms in the internal and external environment through the phenomenon of 'neuronal entrainment', which is attracting increasing attention due to its suggested role in a multitude of sensory and cognitive processes. Some senses, such as touch and vision, sample the environment rhythmically, while others, like audition, are faced with mostly rhythmic inputs. Entrainment couples rhythmic brain activity to external and internal rhythmic events, serving fine-grained routing and modulation of external and internal signals across multiple spatial and temporal hierarchies. This interaction between a brain and its environment can be experimentally investigated and even modified by rhythmic sensory stimuli or invasive and non-invasive neuromodulation techniques. We provide a comprehensive overview of the topic and propose a theoretical framework of how neuronal entrainment dynamically structures information from incoming neuronal, bodily and environmental sources. We discuss the different types of neuronal entrainment, the conceptual advances in the field, and converging evidence for general principles.

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

Behavioral synchronization has been found to facilitate social bonding and prosociality but the neural mechanisms underlying such effects are not well understood. In the current study, 60 dyads were hyperscanned using functional near-infrared spectroscopy while they performed either a synchronous key-pressing task or a control task. After the task, they were asked to perform the dictator game to assess their prosocial behavior. We also measured three potential mediating variables: self–other overlap, perceived similarity and interpersonal neural synchronization. Results showed that dyads in the synchronization group were higher in behavioral synchronization, interpersonal neural synchronization (INS) at the right dorsolateral prefrontal cortex, self–other overlap, perceived similarity and prosociality than those in the control group. INS was significantly associated with prosocial behaviors and self–other overlap. After testing four meditation models, we found that self–other overlap and INS played a serial mediation role in the effect of behavioral synchronization on prosociality. These results contribute to our understanding of the neural and cognitive mechanisms underlying the effect of behavioral synchronization on prosocial behavior.

Actions Speak Louder Than Words: The Role of Action in Self-Referential Advantage in Children With Autism

Impaired self-processing in children with autism spectrum disorder (ASD) is believed to be closely associated with social-communicative deficits, a core symptom of ASD. In three experiments, we aimed to investigate (a) whether children with ASD exhibited deficient in self-processing, as reflected by their superior memory for self-related items as compared to other-related items, and (b) the role that action played in promoting self-processing in ASD. In Experiment 1, children with ASD, children with intellectual disability (ID), and typically developing children were asked to memorize items on the cards assigned to them or to the experimenter. The results indicated that the TD and ID groups had a self-referential memory advantage, but the ASD group did not. Experiments 2 and 3 examined whether the deficit in self-processing among children with ASDs was ameliorated when participants performed or observed an action to indicate the ownership of the items. We found that when children with ASD performed self-generated actions or observed virtual actions, they displayed a similar self-referential memory advantage as the other two groups. Our findings reveal that action plays an important role in the self-processing in children with ASD, and thereby contribute to a more comprehensive understanding of self-processing deficits in this population. Autism Res 2020, 13: 810-820. © 2020 International Society for Autism Research,Wiley Periodicals, Inc. LAY SUMMARY: We aimed to study whether children with autism spectrum disorder (ASD) exhibited deficient in self-processing and the role of action in promoting self-processing in ASD. We found that the typically developing and intellectual disability groups had a self-referential memory advantage, but the ASD group did not. However, children with ASD showed a significant self-referential advantage when they performed or observed an action to indicate the ownership of items. These findings highlight the vital role that action plays in cognitively enhancing their self-processing.

Two-Person Approaches to Studying Social Interaction in Psychiatry: Uses and Clinical Relevance

Social interaction is ubiquitous in human society. The two-person approach-a new, powerful tool to study information exchange and social behaviors-aims to characterize the behavioral dynamics and neural mechanisms of real-time social interactions. In this review, we discuss the benefits of two-person approaches compared to those for conventional, single-person approaches. We describe measures and paradigms that model social interaction in three dimensions (3-D), including eye-to-eye, body-to-body, and brain-to-brain relationships. We then discuss how these two-person measures and paradigms are used in psychiatric conditions (e.g., autism, mood disorders, schizophrenia, borderline personality disorder, and psychotherapy). Furthermore, the advantages of a two-person approach (e.g., dual brain stimulation, multi-person neurofeedback) in clinical interventions are described. Finally, we discuss the methodological and translational challenges surrounding the application of two-person approaches in psychiatry, as well as prospects for future two-/multi-person studies. We conclude that two-person approaches serve as useful additions to the range of behavioral and neuroscientific methods available to assess social interaction in psychiatric settings, for both diagnostic techniques and complementary interventions.

Interpersonal synchrony feels good but impedes self-regulation of affect

The social benefits of interpersonal synchrony are widely recognized. Yet, little is known about its impact on the self. According to enactive cognitive science, the human self for its stability and regulation needs to balance social attunement with disengagement from others. Too much interpersonal synchrony is considered detrimental for a person’s ability to self-regulate. In this study, 66 adults took part in the Body-Conversation Task (BCT), a dyadic movement task promoting spontaneous social interaction. Using whole-body behavioural imaging, we investigated the simultaneous impact of interpersonal synchrony (between persons) and intrapersonal synchrony (within a person) on positive affect and self-regulation of affect. We hypothesized that interpersonal synchrony’s known tendency to increase positive affect would have a trade-off, decreasing a person’s ability to self-regulate affect. Interpersonal synchrony predicted an increase in positive affect. Consistent with our hypothesis, it simultaneously predicted a weakening in self-regulation of affect. Intrapersonal synchrony, however, tended to oppose these effects. Our findings challenge the widespread belief that harmony with others has only beneficial effects, pointing to the need to better understand the impact of interaction dynamics on the stability and regulation of the human self.

INTRApersonal Synchrony as Constituent of INTERpersonal Synchrony and Its Relevance for Autism Spectrum Disorder

INTERpersonal synchrony leads to increased empathy, rapport and understanding, enabling successful human-human interactions and reciprocal bonding. Research shows that individuals with Autism Spectrum Disorder (ASD) exhibit difficulties to INTERpersonally synchronize but underlying causes are yet unknown. In order to successfully synchronize with others, INTRApersonal synchronization of communicative signals appears to be a necessary prerequisite. We understand INTRApersonal synchrony as an implicit factor of INTERpersonal synchrony and therefore hypothesize that atypicalities of INTRApersonal synchrony may add to INTERpersonal synchrony problems in ASD and their interaction partners. In this perspective article, we first review evidence for INTERpersonal dissynchrony in ASD, with respect to different approaches and assessment methods. Second, we draft a theoretical conceptualization of INTRApersonal dissynchrony in ASD based on a temporal model of human interaction. We will outline literature indicating INTRApersonal dissynchrony in ASD, therefore highlighting findings of atypical timing functions and findings from clinical and behavioral studies that indicate peculiar motion patterns and communicative signal production in ASD. Third, we hypothesize that findings from these domains suggest an assessment and investigation of temporal parameters of social behavior in individuals with ASD. We will further propose specific goals of empirical approaches on INTRApersonal dissynchrony. Finally we present implications of research on INTRApersonal timing in ASD for diagnostic and therapeutic purposes, what in our opinion warrants the increase of research efforts in this domain.

Joint Action Enhances Cohesion and Positive Affect, but Suppresses Aspects of Creativity When Combined With Shared Goals

We aimed to examine the link between two types of joint action (synchrony and asynchrony) and creativity (both divergent thinking and convergent thinking) using an established experimental paradigm. A secondary aim was to replicate and extend the amplified positive effects of shared intentionality (i.e., having a shared common goal) on social and affective responses. Participants (N = 138) were randomly assigned to move in synchrony, move in asynchrony, or passively observe others moving. To induce shared goals, participants were provided with either a shared group goal of working together or an individual goal of focusing on the individual participant’s own movements. First, our results revealed that joint action in combination with group goal conditions decreases convergent thinking, but we found no support for differences in divergent thinking. This indicates that it may be the underlying shared goals combined with joint action that influences convergent thinking, and not synchronized movements. Second, we replicated synchrony’s positive effect on cohesion and positive affect. These findings are consistent with evolutionary theories of group rituals as a means for inducing solidarity, and extend previous findings by showing that joint action with shared goals may potentially induce shared patterns of thought.