Mirror game as a tool to influence interpersonal spontaneous behavior after performance.

Mirror game (MG) is an exercise in which participants imitate each other. Our study explored its spontaneous behavioral consequences after performance. In a baseline (BL) phase, two participants performed a joint Simon task. Then, they performed a lure task during which we measured the interpersonal distance they spontaneously adopted. The BL phase was followed by two phases (in counterbalanced order). The MG phase started with a MG, before a procedure like the BL phase. The individual movement (IM) phase started with movements performed alone before a procedure like the BL phase. Interpersonal distance analysis suggested that MG enhanced spontaneous approach toward the partner, whereas IM induced spontaneous avoidance. Moreover, the joint Simon effect (JSE) tended to be smaller after IM, suggesting a decreasing inclination to integrate the partner's response in one's own action plan. Furthermore, in IM phase, JSE decreased as interpersonal distance increased.

Evidence of mutual non-verbal synchrony in learners with severe learning disability and autism, and their support workers: a motion energy analysis study.

Introduction: Some research indicates that neurodivergent people are less likely than "neurotypical" people to adapt their movements to a partner's movements to facilitate interpersonal motor synchrony. Researchers therefore suggest synchrony deficits underlie the social differences associated with autism and other neurodivergences. Intensive Interaction (II) is a client-led approach, where Learning Support Workers (LSW) follow the lead of learners to create balanced and reciprocal interactions. Methods: We aimed to examine the balance of synchrony in learners with autism and Severe Learning Disabilities and their LSWs in a special education college where learners had prior experience with II. Using Motion Energy Analysis, we assessed the degree to which each partner acted as a leader, and hence which partner acted as a follower, during moments of close synchrony. Results: Overall, learners and LSWs showed higher than chance synchrony. There were no differences in the degree to which each partner led the moments of synchrony, or the amount pairs synchronized with zero-lag, where there was no delay between each partners' movements. Discussion: The equal balance of leading and following in the learner and LSW pairs demonstrates that both partners consistently adapted their movements to their partner's movements to facilitate synchrony. The findings tentatively challenge the notion of a synchrony deficit in autism and suggest synchrony can be present in cross-neurotype pairs in comfortable and engaging conditions. We discuss the potential for client-led, movement-based approaches to support smooth interactions across neurotypes.

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.

Exploring the role of emotions and conversation content in interpersonal synchrony: A case study of a couple therapy session.

OBJECTIVE: This exploratory study investigated the association between interpersonal movement and physiological synchronies, emotional processing, and the conversational structure of a couple therapy session using a multimodal, mixed-method approach. METHOD: The video recordings of a couple therapy session, in which the participants' electrodermal activity was recorded, were analyzed. The session was divided into topical episodes, a qualitative analysis was conducted on each topical episode's emotional aspects, conversational structure and content. In addition, movement and physiological synchrony were calculated in each topical episode. Regression models were used to discover the associations between qualitative variables and synchronies. RESULTS: Physiological synchrony was associated with the emotional aspects of the session and to episodes in which the spouses' relationship was addressed, while movement synchrony was only related to emotional valence. No association between synchrony and conversational structure was found. CONCLUSION: The findings suggest that physiological and movement synchrony play distinct roles in psychotherapy. The exploratory study sheds light on the association between momentary synchrony, emotions, and conversational structure in a couple therapy session.

How and Why People Synchronize: An Integrated Perspective.

Academic AbstractInterpersonal synchrony, the alignment of behavior and/or physiology during interactions, is a pervasive phenomenon observed in diverse social contexts. Here we synthesize across contexts and behaviors to classify the different forms and functions of synchrony. We provide a concise framework for classifying the manifold forms of synchrony along six dimensions: periodicity, discreteness, spatial similarity, directionality, leader-follower dynamics, and observability. We also distill the various proposed functions of interpersonal synchrony into four interconnected functions: reducing complexity and improving understanding, accomplishing joint tasks, strengthening social connection, and influencing partners' behavior. These functions derive from first principles, emerge from each other, and are accomplished by some forms of synchrony more than others. Effective synchrony flexibly adapts to social goals and more synchrony is not always better. Our synthesis offers a shared framework and language for the field, allowing for better cross-context and cross-behavior comparisons, generating new hypotheses, and highlighting future research directions.

Neural Representations of Observed Interpersonal Synchrony/Asynchrony in the Social Perception Network.

The visual perception of individuals is thought to be mediated by a network of regions in the occipitotemporal cortex that supports specialized processing of faces, bodies, and actions. In comparison, we know relatively little about the neural mechanisms that support the perception of multiple individuals and the interactions between them. The present study sought to elucidate the visual processing of social interactions by identifying which regions of the social perception network represent interpersonal synchrony. In an fMRI study with 32 human participants (26 female, 6 male), we used multivoxel pattern analysis to investigate whether activity in face-selective, body-selective, and interaction-sensitive regions across the social perception network supports the decoding of synchronous versus asynchronous head-nodding and head-shaking. Several regions were found to support significant decoding of synchrony/asynchrony, including extrastriate body area (EBA), face-selective and interaction-sensitive mid/posterior right superior temporal sulcus, and occipital face area. We also saw robust cross-classification across actions in the EBA, suggestive of movement-invariant representations of synchrony/asynchrony. Exploratory whole-brain analyses also identified a region of the right fusiform cortex that responded more strongly to synchronous than to asynchronous motion. Critically, perceiving interpersonal synchrony/asynchrony requires the simultaneous extraction and integration of dynamic information from more than one person. Hence, the representation of synchrony/asynchrony cannot be attributed to augmented or additive processing of individual actors. Our findings therefore provide important new evidence that social interactions recruit dedicated visual processing within the social perception network that extends beyond that engaged by the faces and bodies of the constituent individuals.

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.

Social motor synchrony in autism spectrum conditions: A systematic review.

LAY ABSTRACT: When two people interact, they often fall into sync with one another by moving their bodies at the same time. Some say autistic people are not as good as non-autistic people at moving at the same time as a partner. This has led some researchers to ask whether measuring synchrony might help diagnose autism. We reviewed the research so far to look at differences in Social Motor Synchrony (SMS) (the way we move together) between autistic people and people they interact with. The research suggests that interactions involving an autistic partner (either two autistic partners, or an autistic and non-autistic partner) show lower synchrony than a non-autistic pair. However, we recognised elements in the research so far that may have affected SMS in interactions involving an autistic person. One way SMS may have been affected in research so far might be the way interactions have been set up in the research studies. Few papers studied interactions between two autistic people or looked at synchrony in comfortable environments with autistic-preferred tasks. The studies also do not explain why synchrony might be different, or weaker, in pairs involving autistic partners. We use these limitations to suggest improvements for future research.

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.

Modeling Emerging Interpersonal Synchrony and its Related Adaptive Short-Term Affiliation and Long-Term Bonding: A Second-Order Multi-Adaptive Neural Agent Model.

When people interact, their behavior tends to become synchronized, a mutual coordination process that fosters short-term adaptations, like increased affiliation, and long-term adaptations, like increased bonding. This paper addresses for the first time how such short-term and long-term adaptivity induced by synchronization can be modeled computationally by a second-order multi-adaptive neural agent model. It addresses movement, affect and verbal modalities and both intrapersonal synchrony and interpersonal synchrony. The behavior of the introduced neural agent model was evaluated in a simulation paradigm with different stimuli and communication-enabling conditions. Moreover, in this paper, mathematical analysis is also addressed for adaptive network models and their positioning within the landscape of adaptive dynamical systems. The first type of analysis addressed shows that any smooth adaptive dynamical system has a canonical representation by a self-modeling network. This implies theoretically that the self-modeling network format is widely applicable, which also has been found in many practical applications using this approach. Furthermore, stationary point and equilibrium analysis was addressed and applied to the introduced self-modeling network model. It was used to obtain verification of the model providing evidence that the implemented model is correct with respect to its design specifications.

Synchrony in psychotherapy: High physiological positive concordance predicts symptom reduction and negative concordance predicts symptom aggravation.

OBJECTIVE: Therapeutic alliance is often considered as a predictor for therapeutic success. This study explored dyadic synchrony of skin conductance response (SCR) during naturalistic therapeutic interactions and investigated its potential as an objective biomarker for predicting therapy effectiveness. METHODS: In this proof-of-concept study, skin conductance from both dyad members was continuously measured via wristbands during psychotherapy. Patients and therapists completed post-session reports capturing their subjective appraisal of therapeutic alliance. Additionally, patients completed symptom questionnaires. Each therapeutic dyad was recorded twice in a follow-up design. The first session of the follow-up group was assessed for physiological synchrony (Single Session Index (SSI)). Therapy outcome was captured by the difference between symptom severity scores over time. RESULTS: SCR synchrony significantly predicted the outcome variable of change in patients' global severity index (GSI). High positive SCR concordance was linked to a reduction in patients' GSI, while negative or small positive SSI values were linked to an increase in patients' GSI. CONCLUSION: The results demonstrate the presence of SCR synchrony in clinical interactions. Skin conductance response synchrony was a significant predictor for change in patients' symptom severity index, emphasizing its potential as an objective biomarker in the context of evidence-based psychotherapy.

Not just in sync: Relations between partners' actions influence the sense of joint agency during joint action.

When people perform joint actions together, they often experience a sense of joint agency ("we did that together"). The current study investigated whether relations between partners' actions within joint actions that require precise interpersonal synchrony influence joint agency, above and beyond the degree of synchrony partners achieve. We employed a mixed-methods approach that combined a quantitative experiment with a qualitative analysis of post-experiment interviews. Partners produced synchronized tone sequences that comprised either constant pitch sequences (simple temporal alignment between partners' actions) or musical duets (complex metrical and harmonic relations between partners' actions). Participants reported stronger joint agency for duets than constant pitches, when comparing trials with equally good synchronization. Post-experiment interviews revealed that joint agency was also influenced by participants' knowledge of the music and their perceptions of task performance, difficulty, and enjoyability. These findings further our understanding of joint agency for joint actions that require precise interpersonal synchrony.

Improvised herding: Mapping biobehavioral mechanisms that underlie group efficacy during improvised social interaction.

Improvisation is a natural occurring phenomenon that is central to social interaction. Yet, improvisation is an understudied area in group processes and intergroup relations. Here we build on theory and research about human herding to study the contributions of improvisation on group efficacy and its biobehavioral underpinnings. We employed a novel multimodal approach and integrative method when observing face-to-face interactions-51 triads (total N = 153) drummed together in spontaneous-free improvisations as a group, while their electrodermal activity was monitored simultaneously with their second-by-second rhythmic coordination on a shared electronic drum machine. Our results show that three hypothesized factors of human herding-physiological synchrony, behavioral coordination, and emotional contagion-predict a sense of group efficacy in its group members. These findings are some of the first to show herding at three levels (physiological, behavioral, and mental) in a single study and lay a basis for understanding the role of improvisation in social interaction.

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.

Musical engagement as a duet of tight synchrony and loose interpretability.

Joint engagement in music often facilitates positive social interaction, effectively shifting participants' perspective from the individual to the collective. The result is tight coordination and uniformity between participants, but at the same time, also remarkable flexibility and creativity. How does music achieve such a fine balance between the strict alignment necessary for coordination, and the substantial latitude necessary for experimentation? To address this question, I propose to analyze joint music engagement within the tight-loose theoretical framework broadly used in the social sciences. Tight-loose theory was originally developed for distinguishing between two archetypical cultural tendencies. On the one hand, tightness, which denotes stringent adherence to social norms, and on the other hand, looseness, which refers to a more flexible and less restrictive attitude towards norms. I posit that the flexible form of collaboration characteristic of musical interaction is due to a coexistence of tightness and looseness within joint engagement in music. I argue that the tight aspects of music can be attributed to its rhythmic structure, which requires continuous and precise temporal alignment between participants. Indeed, when experienced on its own, outside of a musical context, interpersonal synchrony has been repeatedly shown to enhance diverse positive social capacities such as bonding, collaboration and affiliation between interacting individuals, but at the expense of increasing conformity, blind obedience and even hostility towards non-group members. These effects are consistent with synchrony driving a tight interaction, inducing a sense of common group membership (CGM), which can endow music with necessary rigor and order. In contrast, the loose side of music may pertain to the ambiguity in meaning and intention expressed by music, which leaves ample room for interpretation and improvisation. I thus propose that the combined tight-loose nature of music, can simultaneously enhance positive social behaviors and reduce negative ones, leading to a tolerant form of group membership (TGM).

Early Onset of Impairments of Interpersonal Motor Synchrony in Preschool-Aged Children with Autism Spectrum Disorder.

Characteristics of interpersonal motor synchrony in individuals with autism spectrum disorder (ASD) have been investigated only in older children and adolescents, which calls for investigations in younger samples. The interpersonal motor synchrony was compared between preschool-aged children with (n = 23) and without ASD (n = 24) during free plays with familiar teachers. Children with ASD exhibited reduced synchrony of the upper body and trunk compared with typically developing (TD) children. Moreover, the degree of synchrony in ASD group was not above than chance. For autistic children, interpersonal motor synchrony was negatively correlated with aspects of autistic traits. The results suggest that the impairment of interpersonal motor synchrony has an onset earlier than school age and is a potential pathway for understanding autistic traits.

Does interpersonal liking lead to interpersonal synchrony in musical contexts?

The causal relationship of interpersonal liking affecting interpersonal synchrony is inconsistently documented. This study tests whether (a) interpersonal liking increases both behavioural and perceived synchrony and (b) people will synchronise with an agreeable partner over a competing musical stimulus. We had college students (N = 25) shake an egg-shaker with an agreeable or disagreeable confederate without music, with music, and with specific instruction to synchronise. Participants reported liking the agreeable confederate more than the disagreeable confederate and rated their relationship more positively; however, both behavioural and perceived synchrony were unaffected by the agreeableness of the confederate. Thus, we failed to replicate previous findings in an auditory only context. Furthermore, participants who believed they were more synchronised with the confederate liked the confederate more and felt more like a team, but the degree of behavioural synchrony was unrelated to these social perceptions. Perception of synchrony appears to be more important for social bonding than behavioural synchrony.

Language style matching and treatment outcome in anorexia nervosa.

OBJECTIVE: Psychotherapy is the treatment of choice for anorexia nervosa (AN) but mechanisms of action are still largely unknown. Growing research suggests that synchrony between patient and therapist contributes to treatment success. Adding to this literature, this study examined the association between language style matching (LSM) among patient and therapist as an indicator of interpersonal (verbal) synchrony and treatment outcome in AN. METHOD: Audio recordings of mid-treatment therapy sessions (n = 25) in a multi-centre randomized controlled trial on the Maudsley Model of Anorexia Nervosa Treatment for Adults were transcribed and used to calculate LSM for each patient-therapist dyad. These scores were used to predict treatment outcome at 12-month follow-up. RESULTS: LSM did not predict body mass index (primary outcome) at follow-up. However, higher LSM (M = 0.87, SD = 0.04) was associated with lower eating disorder psychopathology (accounting for 11% of the variance) and higher recovery rates (accounting for 28% of variance) at follow-up. CONCLUSIONS: These preliminary findings suggest that verbal synchrony between patients with AN and their therapists contributes to favourable treatment outcomes. High levels of LSM may reflect therapeutic empathy, cooperation, or mutual positive perception. Further research should explore the mechanisms of linguistic synchrony with larger samples to allow for stronger conclusions.

Parent-child dyads with greater parenting stress exhibit less synchrony in posterior areas and more synchrony in frontal areas of the prefrontal cortex during shared play.

Parent-child dyads who are mutually attuned to each other during social interactions display interpersonal synchrony that can be observed behaviorally and through the temporal coordination of brain signals called interbrain synchrony. Parenting stress undermines the quality of parent-child interactions. However, no study has examined synchrony in relation to parenting stress during everyday shared play. The present fNIRS study examined the association between parenting stress and interbrain synchrony in the prefrontal cortex (PFC) of 31 mother-child and 29 father-child dyads while they engaged in shared play for 10 min. Shared play was micro-analytically coded into joint and non-joint segments. Interbrain synchrony was computed using cross-correlations over 15-, 20-, 25-, 30- and 35-s fixed-length windows. Findings showed that stressed dyads exhibited less synchrony in the posterior right cluster of the PFC during joint segments of play, and, contrary to expectations, stressed dyads also showed greater synchrony in the frontal left cluster. These findings suggest that dyads with more parenting stress experienced less similarities in brain areas involved in emotional processing and regulation, whilst simultaneously requiring greater neural entrainment in brain areas that support task management and social-behavioral organization in order to sustain prolonged periods of joint interactions.