Interpersonal touch is of paramount importance in human social bonding and close relationships, allowing a unique channel for affect communication. So far the effect of touch on human physiology has been studied at an individual level. The present study aims at extending the study of affective touch from isolated individuals to truly interacting dyads. We have designed an ecological paradigm where romantic partners interact only via touch and we manipulate their empathic states. Simultaneously, we collected their autonomic activity (skin conductance, pulse, respiration). Fourteen couples participated to the experiment. We found that interpersonal touch increased coupling of electrodermal activity between the interacting partners, regardless the intensity and valence of the emotion felt. In addition, physical touch induced strong and reliable changes in physiological states within individuals. These results support an instrumental role of interpersonal touch for affective support in close relationships. Furthermore, they suggest that touch alone allows the emergence of a somatovisceral resonance between interacting individuals, which in turn is likely to form the prerequisites for emotional contagion and empathy.

We used Near-Infrared Spectroscopy (NIRS) to simultaneously measure brain activity in two people while they played a computer-based cooperation game side by side. Inter-brain activity coherence was calculated between the two participants. We found that the coherence between signals generated by participants' right superior frontal cortices increased during cooperation, but not during competition. Increased coherence was also associated with better cooperation performance. To our knowledge, this work represents the first use of a single NIRS instrument for simultaneous measurements of brain activity in two people. This study demonstrates the use of NIRS-based hyperscanning in studies of social interaction in a naturalistic environment.Copyright © 2011 Elsevier Inc. All rights reserved.

This article reports on a research synthesis of the relation between alliance and the outcomes of individual psychotherapy. Included were over 200 research reports based on 190 independent data sources, covering more than 14,000 treatments. Research involving 5 or more adult participants receiving genuine (as opposed to analogue) treatments, where the author(s) referred to one of the independent variables as "alliance," "therapeutic alliance," "helping alliance," or "working alliance" were the inclusion criteria. All analyses were done using the assumptions of a random model. The overall aggregate relation between the alliance and treatment outcome (adjusted for sample size and non independence of outcome measures) was r =.275 (k = 190); the 95% confidence interval for this value was.25-.30. The statistical probability associated with the aggregated relation between alliance and outcome is p <.0001. The data collected for this meta-analysis were quite variable (heterogeneous). Potential variables such as assessment perspectives (client, therapist, observer), publication source, types of assessment methods and time of assessment were explored.(PsycINFO Database Record (c) 2011 APA, all rights reserved).

The neural mechanism of leader emergence is not well understood. This study investigated (i) whether interpersonal neural synchronization (INS) plays an important role in leader emergence, and (ii) whether INS and leader emergence are associated with the frequency or the quality of communications. Eleven three-member groups were asked to perform a leaderless group discussion (LGD) task, and their brain activities were recorded via functional near infrared spectroscopy (fNIRS)-based hyperscanning. Video recordings of the discussions were coded for leadership and communication. Results showed that the INS for the leader-follower (LF) pairs was higher than that for the follower-follower (FF) pairs in the left temporo-parietal junction (TPJ), an area important for social mentalizing. Although communication frequency was higher for the LF pairs than for the FF pairs, the frequency of leader-initiated and follower-initiated communication did not differ significantly. Moreover, INS for the LF pairs was significantly higher during leader-initiated communication than during follower-initiated communications. In addition, INS for the LF pairs during leader-initiated communication was significantly correlated with the leaders' communication skills and competence, but not their communication frequency. Finally, leadership could be successfully predicted based on INS as well as communication frequency early during the LGD (before half a minute into the task). In sum, this study found that leader emergence was characterized by high-level neural synchronization between the leader and followers and that the quality, rather than the frequency, of communications was associated with synchronization. These results suggest that leaders emerge because they are able to say the right things at the right time.

The aim of this study was to test whether there is statistically significant sympathetic nervous system (SNS) synchrony between participants in couple therapy. To our knowledge, this is the first study to measure psychophysiological synchrony during therapy in a multiactor setting. The study focuses on electrodermal activity (EDA) in the second couple therapy session from 10 different cases (20 clients, 10 therapists working in pairs). The EDA concordance index was used as a measure of SNS synchrony between dyads, and synchrony was found in 85% of all the dyads. Surprisingly, co-therapists exhibited the highest levels of synchrony, whereas couples exhibited the lowest synchrony. The client-therapist synchrony was lower than that of the co-therapists, but higher than that of the couples. A Video Abstract is available next to the online version of this article on the JMFT web site. © 2016 American Association for Marriage and Family Therapy.

The evolution of humans as a highly social species tuned the brain to the social world; yet the mechanisms by which humans coordinate their brain response online during social interactions remain unclear. Using hyperscanning EEG recordings, we measured brain-to-brain synchrony in 104 adults during a male-female naturalistic social interaction, comparing romantic couples and strangers. Neural synchrony was found for couples, but not for strangers, localized to temporal-parietal structures and expressed in gamma rhythms. Brain coordination was not found during a three-minute rest, pinpointing neural synchrony to social interactions among affiliative partners. Brain-to-brain synchrony was linked with behavioral synchrony. Among couples, neural synchrony was anchored in moments of social gaze and positive affect, whereas among strangers, longer durations of social gaze and positive affect correlated with greater neural synchrony. Brain-to-brain synchrony was unrelated to episodes of speech/no-speech or general content of conversation. Our findings link brain-to-brain synchrony to the degree of social connectedness among interacting partners, ground neural synchrony in key nonverbal social behaviors, and highlight the role of human attachment in providing a template for two-brain coordination.

Introduction: The fast expanding field of Interpersonal Physiology (IP) focuses on the study of co-ordination or synchronization dynamics between the physiological activities of two, or more, individuals. IP has been associated with various relational features (e.g., empathy, attachment security, rapport, closeness.) that overlap with desirable characteristics of clinical relationships, suggesting that the relevant studies might provide objective, economical, and theory-free techniques to investigate the clinical process. The goal of the present work is to systematically retrieve and review the literature on IP in the field of psychotherapy and psychological intervention, in order to consolidate the knowledge of this research domain, highlight its critical issues, and delineate possible developments.Method: Following the guidelines by Okoli and Schabram (2010), a systematic literature search was performed in Scopus, Web of Science, PsycINFO, and PubMed databases by means of multiple keyword combinations; the results were integrated with references to the retrieved articles' bibliography as well as to other published reviews on IP.Results: All the retrieved documents reported clinical interactions that are characterized, at least partially, by IP phenomena. They appear to use fragmented and sometimes ambiguous terminology and show a lack of both specific theory-informed hypotheses and sound analytical procedures.Conclusion: Although the psychological nature of IP and its role in the clinical relationship are still mostly unknown, the potential value of a physiology-based measure of implicit exchanges in psychotherapy drives an acceleration in this research field. On the basis of the highlighted critical issues, possible future directions for clinical IP researchers are discussed.

Physiological synchronization is the study of how individuals in interaction coregulate their physiology. The topic has sparked increasing interest in counseling and psychotherapy research, where it has been found to be associated with the therapeutic alliance, clinicians' empathy and patients' outcome. Physiological synchronization allows researcher to investigate subtle but fundamental aspects of the clinical process through objective measures. In this article, we aim to offer a guide to researchers and clinicians to explore this growing field of study. We begin by reviewing the existing literature of physiological synchronization in clinical relationships, and then we provide practical guidelines for research. We discuss the various aspects involved in synchronization studies: study design, selection of physiological signals, data analytic approaches, and interpretation of results. To better illustrate how to implement these types of design, we provide a running example describing the data collection and analysis of a single-case study. In the example we discuss both how to conduct a longitudinal nomothetic analysis, as well as a moment-to-moment idiographic exploration of the clinical content. In this latter analysis, in particular, we show how physiological synchronization can be used in combination with 2 transcripts analysis tools, the Patient Attachment Coding System, and the Therapist Attunement Scales to reach a deeper understanding of the ongoing processes. We conclude by arguing that research in counseling and psychotherapy has much to gain from and contribute to the overall development of our understanding of physiological synchronization in human interaction. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The quality of a team depends on its ability to deliver information through a hierarchy of team members and negotiate processes spanning different time scales. That structure and the behavior that results from it pose problems for researchers because multiply-nested interactions are not easily separated. We explored the behavior of a six-person team engaged in a Submarine Piloting and Navigation (SPAN) task using the tools of dynamical systems. The data were a single entropy time series that showed the distribution of activity across six team members, as recorded by nine-channel electroencephalography (EEG). A single team's data were analyzed for the purposes of illustrating the utility of multifractal analysis and allowing for in-depth exploratory analysis of temporal characteristics. Could the meaningful events experienced by one of these teams be captured using multifractal analysis, a dynamical systems tool that is specifically designed to extract patterns across levels of analysis? Results indicate that nested patterns of team activity can be identified from neural data streams, including both routine and novel events. The novelty of this tool is the ability to identify social patterns from the brain activity of individuals in the social interaction. Implications for application and future directions of this research are discussed.

Synchrony between interacting systems is an important area of nonlinear dynamics in physical systems. Recently psychological researchers from multiple areas of psychology have become interested in nonverbal synchrony (i.e., coordinated motion between two individuals engaged in dyadic information exchange such as communication or dance) as a predictor and outcome of psychological processes. An important step in studying nonverbal synchrony is systematically and validly differentiating synchronous systems from nonsynchronous systems. However, many current methods of testing and quantifying nonverbal synchrony will show some level of observed synchrony even when research participants have not interacted with one another. In this article we demonstrate the use of surrogate data generation methodology as a means of testing new null-hypotheses for synchrony between bivariate time series such as those derived from modern motion tracking methods. Hypotheses generated by surrogate data generation methods are more nuanced and meaningful than hypotheses from standard null-hypothesis testing. We review four surrogate data generation methods for testing for significant nonverbal synchrony within a windowed cross-correlation (WCC) framework. We also interpret the null-hypotheses generated by these surrogate data generation methods with respect to nonverbal synchrony as a specific use of surrogate data generation, which can then be generalized for hypothesis testing of other psychological time series. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A methodological obstacle for the assessment of psychotherapy process concerns the compatibility between nomothetic versus idiographic approaches. Using quantitative methodology at an idiographic level, we seek to narrow this gap for the special case of nonverbal synchrony in psychotherapy dyads. Using quantitative idiographic process analysis (QUIPA), we combined the assessments of nonverbal synchrony-the coordination of patient's and therapist's body-movement-quantified with motion energy analysis (MEA), patient- and therapist session-reports, and patient's self-reports of symptomatology into multivariate time-series of psychotherapy process across the course of = 12 dyadic psychotherapies with a total of = 150 sessions. Adopting both mixed models as well as vector auto regressive models (VAR) to time-series, we aimed to extend previous results assessed in a randomized sample by exploring the evolution of nonverbal synchrony in psychotherapy dyads across time. Aggregated idiographic data revealed that nonverbal synchrony was different from findings based on a previously reported nomothetic account: Associations with session-level outcome were weaker and did not replicate cross-sectional analyses. The application of idiographic assessments may help broadening our conception of synchrony in psychotherapy and also reminds us that ergodicity is not necessarily the usual case, but one of many possibilities.

The authors quantified nonverbal synchrony--the coordination of patient's and therapist's movement--in a random sample of same-sex psychotherapy dyads. The authors contrasted nonverbal synchrony in these dyads with a control condition and assessed its association with session-level and overall psychotherapy outcome.Using an automated objective video analysis algorithm (Motion Energy Analysis; MEA), the authors calculated nonverbal synchrony in (n = 104) videotaped psychotherapy sessions from 70 Caucasian patients (37 women, 33 men, mean age = 36.5 years, SD = 10.2) treated at an outpatient psychotherapy clinic. The sample was randomly drawn from an archive (N = 301) of routinely videotaped psychotherapies. Patients and their therapists assessed session impact with self-report post-session questionnaires. A battery of pre- and postsymptomatology questionnaires measured therapy effectiveness.The authors found that nonverbal synchrony is higher in genuine interactions contrasted with pseudointeractions (a control condition generated by a specifically designed shuffling procedure). Furthermore, nonverbal synchrony is associated with session-level process as well as therapy outcome: It is increased in sessions rated by patients as manifesting high relationship quality and in patients experiencing high self-efficacy. Higher nonverbal synchrony characterized psychotherapies with higher symptom reduction.The results suggest that nonverbal synchrony embodies the patients' self-reported quality of the relationship and further variables of therapy process. This hitherto overlooked facet of therapeutic relationships might prove useful as an indicator of therapy progress and outcome.(PsycINFO Database Record (c) 2011 APA, all rights reserved).

Previous work has shown that nonverbal behavior was associated with both session-level outcome and global outcome in psychotherapy. Nonverbal synchrony--here the coordination between patient's and psychotherapist's movement behavior--is a facet of nonverbal behavior that has recently been studied with video-based motion energy analysis (MEA). The present study aimed to replicate and extend these findings by using direct acquisition of movement data. In a single-case analysis, we monitored patient's and therapist's hand movements with a high-resolution accelerometric measurement system (Vitaport (r)). In addition to these behavioral data, both patient and therapist provided session-level ratings of various factors relevant to the psychotherapy process, which were assessed with post-session questionnaires. The patient-therapist coordination of hand movements, i.e. nonverbal synchrony, in (N = 27) sessions of this dyadic psychotherapy was positively associated with progress reported in post-session questionnaires. Sessions with good evaluations concerning the quality of therapeutic alliance were characterized by high movement coordination. Thus, accelerometric data of this therapy dyad confirmed previous findings gained through video analyses: The coordination of nonverbal behavior shown by patient and therapist was an indicator of beneficial processes occurring within sessions. This replication study showed that nonverbal synchrony embodies important aspects of the alliance. Its assessment and quantification may provide therapists important additional information on processes that usually occur outside conscious awareness, but that nevertheless influence core aspects of the therapy.

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.

Premature termination is a problem in psychotherapy. In addition to the examination of demographic and clinical variables as predictors of dropout, research indicates the importance of dyadic variables. Nonverbal synchrony (e.g., movement synchrony) operationalizes the coordination of patient and therapist and is a promising candidate for predicting premature termination. This secondary data analysis included data on patients with social anxiety disorder ( = 267) that were treated with > 20 sessions of cognitive-behavioral therapy or psychodynamic therapy. Therapy outcome was measured by the Inventory of Interpersonal Problems and the Beck Depression Inventory. Individual movements in the third session were assessed by motion energy analysis. Movement synchrony was identified with a windowed cross-lagged correlation and peak-picking algorithm. We performed logistic regressions and mixed effects Cox regressions to investigate synchrony as a predictor of premature termination. Therapist-patient dyads that included a patient who terminated psychotherapy prematurely had significantly lower movement synchrony at the beginning of therapy than patients who completed therapy. Gender-matching and therapeutic approach had a (marginally) significant effect in moderating the relationship. Therefore, low movement synchrony in early therapy sessions may contain clues to premature termination and reflect a mismatch between the patient and therapist or problems in the therapeutic alliance. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

In previous research, we found that sympathetic nervous system synchrony, measured via electrodermal activity (EDA), occurs between participants at the start of couple therapy. The aim now was to test whether this synchrony changes during the therapy process, and how any changes may be related to clients' and therapists' evaluations of the working alliance, and the outcome of therapy. Twelve different couple therapy processes were analyzed (24 clients, plus 10 therapists, working in pairs; hence, 4 persons per session) using EDA concordance indices and questionnaires (Outcome Rating Scale, Session Rating Scale, and Clinical Outcomes in Routine Evaluation-Outcome Measure). EDA synchrony between the couples increased from the beginning to the end of therapy. This seemed to be connected to a positive linear trend in female clients' well-being during the therapy process. There were no statistically significant changes in the EDA synchrony between the cotherapists, or between the clients and the therapists. We found specific changes in the EDA synchrony to be related to changes in the therapeutic alliance, and/or changes in the clients' well-being. Heightened EDA synchrony was frequently related to a better outcome; nevertheless, there was one instance in which decreasing synchrony seemed to be more beneficial. It appears that couple therapy can bring spouses closer together also on a physiological level, which could be especially important for the well-being of women. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

There is broad consensus that the therapeutic alliance constitutes a core common factor for all modalities of psychotherapy. Meta-analyses corroborated that alliance, as it emerges from therapeutic process, is a significant predictor of therapy outcome. Psychotherapy process is traditionally described and explored using two categorically different approaches, the experiential (first-person) perspective and the behavioral (third-person) perspective. We propose to add to this duality a third, structural approach. Dynamical systems theory and synergetics on the one hand and enactivist theory on the other together can provide this structural approach, which contributes in specific ways to a clarification of the alliance factor. Systems theory offers concepts and tools for the modeling of the individual self and, building on this, of alliance processes. In the enactive perspective, the self is conceived as a socially enacted autonomous system that strives to maintain identity by observing a two-fold goal: to exist as an individual self in its own right (distinction) while also being open to others (participation). Using this conceptualization, we formalized the therapeutic alliance as a phase space whose potential minima (attractors) can be shifted by the therapist to approximate therapy goals. This mathematical formalization is derived from probability theory and synergetics. We draw the conclusion that structural theory provides powerful tools for the modeling of how therapeutic change is staged by the formation, utilization, and dissolution of the therapeutic alliance. In addition, we point out novel testable hypotheses and future applications.

In this proof-of-principle study, a convenience sample of 55 dyadic psychotherapy sessions conducted by one therapist was analyzed. This study aimed at exploring physiological synchrony in naturalistic psychotherapy sessions and the association of such synchrony with self-report ratings. The electrocardiograms and respiration behavior of both therapist and client were monitored simultaneously. Four clients were included, and session outcome was documented by session reports in two clients. From electrocardiograms, heart rate and heart rate variability were derived in consecutive 15-second intervals throughout sessions. Entire sessions (average duration, 51 min) were assessed for physiological synchrony of therapist's and client's respiration, electrocardiogram, heart rate, and heart rate variability. Two methods of synchrony computation were applied to the time series: windowed cross-correlation and correlation of local slopes (concordance). Both methods included surrogate controls using segment-wise shuffling. Significant synchrony of three measures, but not of electrocardiograms, was present in this dataset. In regression models, we found associations between synchronies and alliance ratings, and further self-report variables. Results support the existence of physiological synchrony in this collection of psychotherapy sessions, which speaks for the sympathetic and parasympathetic coupling between this therapist and her clients and its link with ratings of the therapy process. The feasibility of deriving signatures of synchrony of physiological signals with the described methodology was corroborated. The findings now await generalization by further research.

Chronic early trauma alters children's stress reactivity and increases the prevalence of anxiety disorders; yet the neuroendocrine and immune mechanisms underpinning this effect are not fully clear. Animal studies indicate that the mother's physiology and behavior mediate offspring stress in a system-specific manner, but few studies tested this external-regulatory maternal role in human children exposed to chronic stress.We followed a unique cohort of children exposed to continuous wartime trauma (N = 177; exposed; N = 101, controls; N = 76). At 10 years, maternal and child's salivary immunoglobulin A (s-IgA) and oxytocin (OT), biomarkers of the immune and affiliation systems, were assayed, maternal and child relational behaviors observed, mother and child underwent psychiatric diagnosis, and child anxiety symptoms assessed.War-exposed mothers had higher s-IgA, lower OT, more anxiety symptoms, and their parenting was characterized by reduced sensitivity. Exposed children showed higher s-IgA, more anxiety disorders and post traumatic stress disorder, and more anxiety symptoms. Path analysis model defined three pathways by which maternal physiology and behavior impacted child anxiety; (a) increasing maternal s-IgA, which led to increased child s-IgA, augmenting child anxiety; (b) reducing maternal OT, which linked with diminished child OT and social repertoire; and (c) increasing maternal anxiety, which directly impacted child anxiety.Our findings, the first to measure immune and affiliation biomarkers in mothers and children, detail their unique and joint effects on children's anxiety in response to stress; highlight the relations between chronic stress, immune activation, and anxiety in children; and describe how processes of biobehavioral synchrony shape children's long-term adaptation.

Oxytocin (OT) synchrony has been suggested as a key mechanism by which bonds are formed and strengthened in various species, including those between mother and infant and between romantic partners. It is unknown whether such biological synchrony also plays a role in psychotherapy efficacy, where it may underlie the adverse effect of social impairment on the efficacy of treatment of depression.Five hundred eighty OT saliva samples were collected from 37 patient-therapist dyads on a fixed schedule over a 16-session ongoing randomized controlled trial for psychotherapy for depression. Biological synchrony was operationalized as the correlation between changes occurring repeatedly over treatment in patient and therapist OT levels pre- to postsession.OT synchrony between patients and therapists was found to be associated with effective treatment. The findings support the proposed mediation model: (a) poorer social functioning at baseline predicted lower levels of patient-therapist synchrony in OT changes from pre- to postsession over the course of treatment; (b) lower levels of therapist-patient OT synchrony, in turn, predicted less reduction in depressive symptoms during treatment; and (c) based on quasi-Bayesian Monte Carlo simulations, the levels of therapist-patient synchrony significantly mediated the association between social impairment and reduction in depressive symptoms. Findings were replicated using robust inferential methods.The findings suggest that OT synchrony between patient and therapist may be a biological mechanism by which impaired interpersonal functioning undermines treatment outcome. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The therapeutic alliance is one of the most consistent predictors of therapeutic change, including symptom reduction and improvement in wellbeing and quality of life, across a variety of mental health interventions. Yet, little is known about its biological mechanisms. Oxytocin (OT) has been suggested as a biological mechanism by which bonds are formed and strengthened across species. This article is intended to demonstrate the potential of OT as a biomarker of therapeutic change in psychotherapy and counseling psychology, especially of the therapeutic alliance. We delineate three main potential paths of investigation based on the most recent research on OT in parent-child and romantic partner dyads. For each path, we provide a detailed explanation for whom, when, and how OT should be measured. Each path is illustrated using data collected in a randomized controlled trial of psychotherapy for major depressive disorder. These illustrations demonstrate the great potential of OT as a biomarker of (a) trait-like characteristics of the patients and the therapists, (b) the processes of therapeutic change, and (c) the dyadic synchrony between patients and their therapists. The potential clinical contribution of OT as a biomarker for each of these three paths is further demonstrated using a case study. Practical suggestions and directions for future research are discussed. (PsycInfo Database Record (c) 2020 APA, all rights reserved).