Synchrony in the periphery: inter-subject correlation of physiological responses during live music concerts

Acquiring musical knowledge increases music liking: Evidence from a neurophysiological study

People possessing musical knowledge tend to enjoy music more, but the linkage remains to be determined. Based on the shared affective motion experience model for music appreciation, we hypothesized that acquiring musical knowledge about the music itself, for example, an analytical understanding of music elements and the related emotional expressions, would increase music liking. To test the hypothesis, we asked 48 participants to learn analytical or historical information about a piece of music by watching a pre-recorded teaching video. Learners' physiological responses, such as skin conductance and heart rate, were recorded during learning. The increase of music liking was observed after both types of knowledge acquisition, but more so for analytical knowledge. Notably, acquiring analytical knowledge made learners' skin conductance more similar, indicating the alignment of physiological responses. This physiological similarity, correlated with analytical knowledge similarity, could mediate the effect of knowledge acquisition on music liking. In sum, this study reveals the impact of analytical knowledge on music enjoyment and the associated neurophysiological mechanism. It extends the theoretical framework of shared affective motion experience to explain how musical knowledge influences music appreciation.

Physiological audience synchrony in classical concerts linked with listeners' experiences and attitudes

A series of eleven public concerts (staging chamber music by Ludwig van Beethoven, Brett Dean, Johannes Brahms) was organized with the goal to analyze physiological synchronies within the audiences and associations of synchrony with psychological variables. We hypothesized that the music would induce synchronized physiology, which would be linked to participants' aesthetic experiences, affect, and personality traits. Physiological measures (cardiac, electrodermal, respiration) of 695 participants were recorded during presentations. Before and after concerts, questionnaires provided self-report scales and standardized measures of participants' affectivity, personality traits, aesthetic experiences and listening modes. Synchrony was computed by a cross-correlational algorithm to obtain, for each participant and physiological variable (heart rate, heart-rate variability, respiration rate, respiration, skin-conductance response), how much each individual participant contributed to overall audience synchrony. In hierarchical models, such synchrony contribution was used as the dependent and the various self-report scales as predictor variables. We found that physiology throughout audiences was significantly synchronized, as expected with the exception of breathing behavior. There were links between synchrony and affectivity. Personality moderated the synchrony levels: Openness was positively associated, Extraversion and Neuroticism negatively. Several factors of experiences and listening modes predicted synchrony. Emotional listening was associated with reduced, whereas both structual and sound-focused listening was associated with increased synchrony. We concluded with an updated, nuanced understanding of synchrony on the timescale of whole concerts, inviting elaboration by synchony studies on shorter timescales of music passages.

Inter-subject correlation of audience facial expressions predicts audience engagement during theatrical performances

During performances, audiences experience various emotional states, and these are reflected in their ongoing facial expressions. We investigated if audience engagement could be determined by measuring the inter-subject correlation (ISC) of non-invasively recorded audience facial expressions. We filmed the faces of multiple audience members at theatrical performances and determined the intensity of their different facial expressions throughout the performances. Neutral, happy, anger, and disgust expression ISCs accounted for up to 24% of the performance dramaturge's predictions of audience engagement. Expression synchrony was greater between individuals in close proximity, suggesting effects of emotional contagion or cognitive similarities between neighboring individuals, whereas expression synchrony was greatest between individuals who were younger, female, and with greater levels of empathy, showing that individual characteristics impact shared audience experiences. Together, our results show that facial expression synchronization could be used as a real-time non-invasive indicator of engagement in audiences larger than achieved using previous approaches.

Inter-subject correlation of electroencephalographic and behavioural responses reflects time-varying engagement with natural music

Musical engagement can be conceptualized through various activities, modes of listening and listener states. Recent research has reported that a state of focused engagement can be indexed by the inter-subject correlation (ISC) of audience responses to a shared naturalistic stimulus. While statistically significant ISC has been reported during music listening, we lack insight into the temporal dynamics of engagement over the course of musical works-such as those composed in the Western classical style-which involve the formulation of expectations that are realized or derailed at subsequent points of arrival. Here, we use the ISC of electroencephalographic (EEG) and continuous behavioural (CB) responses to investigate the time-varying dynamics of engagement with functional tonal music. From a sample of adult musicians who listened to a complete cello concerto movement, we found that ISC varied throughout the excerpt for both measures. In particular, significant EEG ISC was observed during periods of musical tension that built to climactic highpoints, while significant CB ISC corresponded more to declarative entrances and points of arrival. Moreover, we found that a control stimulus retaining envelope characteristics of the intact music, but little other temporal structure, also elicited significantly correlated EEG and CB responses, though to lesser extents than the original version. In sum, these findings shed light on the temporal dynamics of engagement during music listening and clarify specific aspects of musical engagement that may be indexed by each measure.

Reliability for music-induced heart rate synchronization

Common inputs synchronize various biological systems, including human physical and cognitive processes. This mechanism potentially explains collective human emotions in theater as unintentional behavioral synchronization. However, the inter-subject correlation of physiological signals among individuals is small. Based on findings on the common-input synchronization of nonlinear systems, we hypothesized that individual differences in perceptual and cognitive systems reduce the reliability of physiological responses to aesthetic stimuli and, thus, disturb synchronization. We tested this by comparing the inter- and intra-subject Pearson's correlation coefficients and nonlinear phase synchronization, calculated using instantaneous heart rate data measured while appreciating music. The results demonstrated that inter-subject correlations were consistently lower than intra-subject correlations, regardless of participants' music preferences and daily moods. Further, music-induced heart rate synchronization depends on the reliability of physiological responses to musical pieces rather than mood or motivation. This study lays the foundation for future empirical research on collective emotions in theater.

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.

Consistent movement of viewers' facial keypoints while watching emotionally evocative videos

Neuropsychological research aims to unravel how diverse individuals' brains exhibit similar functionality when exposed to the same stimuli. The evocation of consistent responses when different subjects watch the same emotionally evocative stimulus has been observed through modalities like fMRI, EEG, physiological signals and facial expressions. We refer to the quantification of these shared consistent signals across subjects at each time instant across the temporal dimension as Consistent Response Measurement (CRM). CRM is widely explored through fMRI, occasionally with EEG, physiological signals and facial expressions using metrics like Inter-Subject Correlation (ISC). However, fMRI tools are expensive and constrained, while EEG and physiological signals are prone to facial artifacts and environmental conditions (such as temperature, humidity, and health condition of subjects). In this research, facial expression videos are used as a cost-effective and flexible alternative for CRM, minimally affected by external conditions. By employing computer vision-based automated facial keypoint tracking, a new metric similar to ISC, called the Average t-statistic, is introduced. Unlike existing facial expression-based methodologies that measure CRM of secondary indicators like inferred emotions, keypoint, and ICA-based features, the Average t-statistic is closely associated with the direct measurement of consistent facial muscle movement using the Facial Action Coding System (FACS). This is evidenced in DISFA dataset where the time-series of Average t-statistic has a high correlation (R2 = 0.78) with a metric called AU consistency, which directly measures facial muscle movement through FACS coding of video frames. The simplicity of recording facial expressions with the automated Average t-statistic expands the applications of CRM such as measuring engagement in online learning, customer interactions, etc., and diagnosing outliers in healthcare conditions like stroke, autism, depression, etc. To promote further research, we have made the code repository publicly available.

Research Trends in Virtual Reality Music Concert Technology: A Systematic Literature Review

Advances in virtual reality (VR) technology have sparked novel avenues of growth in the musical domain. Following the COVID-19 pandemic, the rise of VR technology has led to growing interest in VR music concerts as an alternative to traditional live concerts. These virtual settings can provide immersion like attending real concerts for physically distant audiences and performers, and also can offer new creative possibilities. VR music concert research is still in its infancy, and advances in technologies such as multimodal devices are rapidly expanding the diversity of research, requiring a unified understanding of the field. To identify trends in VR music concert technology, we conducted a PRISMA-based systematic literature review covering the period from 2018 to 2023. After a thorough screening process, a total of 27 papers were selected for review. The studies were classified and analyzed based on the research topic (audience, performer, concert venue), interaction type (user-environment, user-user), and hardware used (head-mounted display, additional hardware). Furthermore, we categorized the evaluation metrics into user experience, usability, and performance. Our review contributes to advancing the understanding of recent developments in VR music concert technology, shedding light on the diversification and potential of this emerging field.

Theater practice and interpersonal synchronization behaviors: a pilot study comparing actors and non-actors

Recent studies in the field of theater studies no longer view theater as an object, but rather as a dynamic relationship between actors and spectators. In an embodied and situated perspective of cognition, imagination emerges as a product of this dynamic. This study aims to investigate whether acting practice enhances someone's abilities to set up an effective relationship with others and allows the individual to better manage not only the relationship itself, but also her/his own feelings and those of her/his partner. Eighty two healthy Italian adults, with no communication disorders, including 43 actors (Mage = 25.4; S.D. = 3.64) and 39 non-actors (Mage = 24.1 = S.D. = 4.17) completed a joint verbal production task named Random Sequence Generation (RSG) task. Initially, participants performed the task individually. Subsequently, in a second phase, they worked in pairs with another participant, taking turns to contribute to a shared sequence. Pairings were predetermined to ensure a balanced mix of actors and non-actors, and to prevent participants from having prior relationships. Following the task, subjects were queried about their sense of presence, and, their perception of entitativity with their partner. We observed a replication of previous studies, showing higher RSG scores and reduced repetition in the paired condition, indicative of coupling and synchronization behavior. Within pairs, the level of the sense of presence of both partners was positively correlated. Furthermore, an interaction effect between the sense of presence and acting experience on the perception of entitativity was observed. Specifically, actors described perceived entitativity with their partners when their sense of presence was heightened, whereas non-actors experienced a decrease in perceived entitativity with their partners under similar circumstances. We discuss the results and limitations of the study, suggesting the effect of artistic practice on the development of a sort of dual-task ability which enables actors to organize their sensations and actions while sustaining a meaningful connection with others. This research represents an interdisciplinary collaboration between theater studies and cognitive sciences, highlighting the value of a multidisciplinary approach to research.

Live music stimulates the affective brain and emotionally entrains listeners in real time

Music is powerful in conveying emotions and triggering affective brain mechanisms. Affective brain responses in previous studies were however rather inconsistent, potentially because of the non-adaptive nature of recorded music used so far. Live music instead can be dynamic and adaptive and is often modulated in response to audience feedback to maximize emotional responses in listeners. Here, we introduce a setup for studying emotional responses to live music in a closed-loop neurofeedback setup. This setup linked live performances by musicians to neural processing in listeners, with listeners' amygdala activity was displayed to musicians in real time. Brain activity was measured using functional MRI, and especially amygdala activity was quantified in real time for the neurofeedback signal. Live pleasant and unpleasant piano music performed in response to amygdala neurofeedback from listeners was acoustically very different from comparable recorded music and elicited significantly higher and more consistent amygdala activity. Higher activity was also found in a broader neural network for emotion processing during live compared to recorded music. This finding included observations of the predominance for aversive coding in the ventral striatum while listening to unpleasant music, and involvement of the thalamic pulvinar nucleus, presumably for regulating attentional and cortical flow mechanisms. Live music also stimulated a dense functional neural network with the amygdala as a central node influencing other brain systems. Finally, only live music showed a strong and positive coupling between features of the musical performance and brain activity in listeners pointing to real-time and dynamic entrainment processes.

From pre-processing to advanced dynamic modeling of pupil data

The pupil of the eye provides a rich source of information for cognitive scientists, as it can index a variety of bodily states (e.g., arousal, fatigue) and cognitive processes (e.g., attention, decision-making). As pupillometry becomes a more accessible and popular methodology, researchers have proposed a variety of techniques for analyzing pupil data. Here, we focus on time series-based, signal-to-signal approaches that enable one to relate dynamic changes in pupil size over time with dynamic changes in a stimulus time series, continuous behavioral outcome measures, or other participants' pupil traces. We first introduce pupillometry, its neural underpinnings, and the relation between pupil measurements and other oculomotor behaviors (e.g., blinks, saccades), to stress the importance of understanding what is being measured and what can be inferred from changes in pupillary activity. Next, we discuss possible pre-processing steps, and the contexts in which they may be necessary. Finally, we turn to signal-to-signal analytic techniques, including regression-based approaches, dynamic time-warping, phase clustering, detrended fluctuation analysis, and recurrence quantification analysis. Assumptions of these techniques, and examples of the scientific questions each can address, are outlined, with references to key papers and software packages. Additionally, we provide a detailed code tutorial that steps through the key examples and figures in this paper. Ultimately, we contend that the insights gained from pupillometry are constrained by the analysis techniques used, and that signal-to-signal approaches offer a means to generate novel scientific insights by taking into account understudied spectro-temporal relationships between the pupil signal and other signals of interest.

A model of time-varying music engagement

The current paper offers a model of time-varying music engagement, defined as changes in curiosity, attention and positive valence, as music unfolds over time. First, we present research (including new data) showing that listeners tend to allocate attention to music in a manner that is guided by both features of the music and listeners' individual differences. Next, we review relevant predictive processing literature before using this body of work to inform our model. In brief, we propose that music engagement, over the course of an extended listening episode, may constitute several cycles of curiosity, attention and positive valence that are interspersed with moments of mind-wandering. Further, we suggest that refocusing on music after an episode of mind-wandering can be due to triggers in the music or, conversely, mental action that occurs when the listener realizes they are mind-wandering. Finally, we argue that factors that modulate both overall levels of music engagement and how it changes over time include music complexity, listener background and the listening context. Our paper highlights how music can be used to provide insights into the temporal dynamics of attention and into how curiosity might emerge in everyday contexts. This article is part of the theme issue 'Art, aesthetics and predictive processing: theoretical and empirical perspectives'.

A real-world dataset of group emotion experiences based on physiological data

Affective computing has experienced substantial advancements in recognizing emotions through image and facial expression analysis. However, the incorporation of physiological data remains constrained. Emotion recognition with physiological data shows promising results in controlled experiments but lacks generalization to real-world settings. To address this, we present G-REx, a dataset for real-world affective computing. We collected physiological data (photoplethysmography and electrodermal activity) using a wrist-worn device during long-duration movie sessions. Emotion annotations were retrospectively performed on segments with elevated physiological responses. The dataset includes over 31 movie sessions, totaling 380 h+ of data from 190+ subjects. The data were collected in a group setting, which can give further context to emotion recognition systems. Our setup aims to be easily replicable in any real-life scenario, facilitating the collection of large datasets for novel affective computing systems.

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.

Examining the consistency of continuous affect annotations and psychophysiological measures in response to emotional videos

Despite the growing necessity of understanding the dynamics of emotion by naturalistic stimuli, averaging time-locked responses seems insufficient to capture emotional experiences that change over time. Intersubject correlation (ISC) has been implemented to examine dynamic emotional experiences by quantifying the consistency of responses across individuals. While previous research has shown that enhanced psychophysiological ISC can capture dynamic emotional experiences in response to long-lasting videos that evoke dimensional emotions, it is not yet fully understood how psychophysiological consistency varies during videos that elicit distinct emotions, such as fear. In this study, we re-analyzed publicly available data consisting of continuous affect annotations and psychophysiological signals, namely heart rate (HR), electrodermal activity (EDA), electromyographic signals from zygomaticus major (EMG-z), and corrugator supercilii (EMG-c), in response to categorical emotional videos, namely amusing, boring, relaxing, and fearful. Results showed an overall increase in ISC in multiple measures during fearful videos, indicating that emotional experiences during fearful videos were reliably consistent across participants. The effect of amusing and boring videos on ISC revealed varying results depending on the measurements. In particular, larger ISC in valence rating, EDA, and EMG-z was found for amusing than boring videos, whereas larger ISC in HR and EMG-c was observed for boring than amusing movies. Lastly, decreased ISC for relaxing videos was observed across multiple measurements, showing inconsistent emotional experiences during relaxing videos. This study builds on previous research on physiological consistency during emotional experiences by examining how the consistency of continuous affect annotations and psychophysiological measures differs in response to videos that elicit distinct emotions.

Audience synchronies in live concerts illustrate the embodiment of music experience

A study of 132 audience members of three classical public concerts (all three staged the same chamber music pieces by Ludwig van Beethoven, Brett Dean, and Johannes Brahms) had the goal of analyzing the physiological and motor responses of audiences. It was assumed that the music would induce synchronous physiology and movement in listeners (induction synchrony). In addition to hypothesizing that such synchronies would be present, we expected that they were linked to participants' aesthetic experiences, their affect and personality traits, which were assessed by questionnaires before and after the concerts. Clear evidence was found of physiological synchrony (heart rate, respiration rate, skin conductance response) as well as movement synchrony of the audiences, whereas breathing behavior was not synchronized. Thus the audiences of the three concerts resonated with the music, their music perception was embodied. There were links between the bodily synchrony and aesthetic experiences: synchrony, especially heart-rate synchrony, was higher when listeners felt moved emotionally and inspired by a piece, and were immersed in the music. Personality traits were also associated with the individual contributions to induction synchrony.

Aesthetic and physiological effects of naturalistic multimodal music listening

Compared to audio only (AO) conditions, audiovisual (AV) information can enhance the aesthetic experience of a music performance. However, such beneficial multimodal effects have yet to be studied in naturalistic music performance settings. Further, peripheral physiological correlates of aesthetic experiences are not well-understood. Here, participants were invited to a concert hall for piano performances of Bach, Messiaen, and Beethoven, which were presented in two conditions: AV and AO. They rated their aesthetic experience (AE) after each piece (Experiment 1 and 2), while peripheral signals (cardiorespiratory measures, skin conductance, and facial muscle activity) were continuously measured (Experiment 2). Factor scores of AE were significantly higher in the AV condition in both experiments. LF/HF ratio, a heart rhythm that represents activation of the sympathetic nervous system, was higher in the AO condition, suggesting increased arousal, likely caused by less predictable sound onsets in the AO condition. We present partial evidence that breathing was faster and facial muscle activity was higher in the AV condition, suggesting that observing a performer's movements likely enhances motor mimicry in these more voluntary peripheral measures. Further, zygomaticus ('smiling') muscle activity was a significant predictor of AE. Thus, we suggest physiological measures are related to AE, but at different levels: the more involuntary measures (i.e., heart rhythms) may reflect more sensory aspects, while the more voluntary measures (i.e., muscular control of breathing and facial responses) may reflect the liking aspect of an AE. In summary, we replicate and extend previous findings that AV information enhances AE in a naturalistic music performance setting. We further show that a combination of self-report and peripheral measures benefit a meaningful assessment of AE in naturalistic music performance settings.

Physiological synchrony and shared flow state in Javanese gamelan: positively associated while improvising, but not for traditional performance

The experience of shared flow refers to the optimal balance between challenge and ability for a given task, resulting from interpersonal action in a group situation. The performance of Javanese gamelan is an ideal setting to investigate shared flow, due to the requirement that all performers on varying instrumental parts work harmoniously, allowing for shared flow and its native equivalent, ngeli. To minimise the disruption of flow, while still measuring it continuously, one way to assess a person's state is by measuring physiological responses of the sympathetic (i.e., fight-or-flight) system, namely heart rate and skin conductance. Flow has been related to physiological signatures, and shared actions in music-making have been related to synchronised physiology. However, to our knowledge, no study yet has directly investigated the links between shared physiology and shared flow. Therefore, this study aimed to assess the associations between flow states, physiological synchrony, and Javanese gamelan playing. Subsequently, we tested for differences between advanced and beginner groups playing traditional gamelan pieces and improvising. Firstly, a factor analysis revealed a two-factor solution of Awareness and Absorption for self-reported shared flow. Next, using inter-subject correlation to assess synchrony and circular shuffling to infer significance, we found a greater proportion of significance in traditional playing compared to improvised playing for the experienced group, and the opposite for the beginner group. Lastly, linear mixed models revealed largely positive associations between synchronised physiology and shared flow during improvised playing, and negative associations during traditional playing, regardless of experience levels. This study demonstrates methodological possibilities for the quantitative study of shared flow in music-making contexts, and potential differences in shared flow experience in improvised and traditional, or prescribed, playing.

Measuring real-time cognitive engagement in remote audiences

Responses to arts and entertainment media offer a valuable window into human behaviour. Many individuals worldwide spend the vast majority of their leisure time engaging with video content at home. However, there are few ways to study engagement and attention in this natural home viewing context. We used motion-tracking of the head via a web-camera to measure real-time cognitive engagement in 132 individuals while they watched 30 min of streamed theatre content at home. Head movement was negatively associated with engagement across a constellation of measures. Individuals who moved less reported feeling more engaged and immersed, evaluated the performance as more engaging, and were more likely to express interest in watching further. Our results demonstrate the value of in-home remote motion tracking as a low-cost, scalable metric of cognitive engagement, which can be used to collect audience behaviour data in a natural setting.

Audience immersion: validating attentional and physiological measures against self-report

When an audience member becomes immersed, their attention shifts towards the media and story, and they allocate cognitive resources to represent events and characters. Here, we investigate whether it is possible to measure immersion using continuous behavioural and physiological measures. Using television and film clips, we validated dual-task reaction times, heart rate, and skin conductance against self-reported narrative engagement. We find that reaction times to a secondary task were strongly positively correlated with self-reported immersion: slower reaction times were indicative of greater immersion, particularly emotional engagement. Synchrony in heart rate across participants was associated with self-reported attentional and emotional engagement with the story, although we found no such relationship with skin conductance. These results establish both dual-task reaction times and heart rate as candidate measures for the real-time, continuous, assessment of audience immersion.

The neuroscience of music – towards ecological validity

Studies in the neuroscience of music gained momentum in the 1990s as an integrated part of the well-controlled experimental research tradition. However, during the past two decades, these studies have moved toward more naturalistic, ecologically valid paradigms. Here, I introduce this move in three frameworks: (i) sound stimulation and empirical paradigms, (ii) study participants, and (iii) methods and contexts of data acquisition. I wish to provide a narrative historical overview of the development of the field and, in parallel, to stimulate innovative thinking to further advance the ecological validity of the studies without overlooking experimental rigor.

On the encoding of natural music in computational models and human brains

This article discusses recent developments and advances in the neuroscience of music to understand the nature of musical emotion. In particular, it highlights how system identification techniques and computational models of music have advanced our understanding of how the human brain processes the textures and structures of music and how the processed information evokes emotions. Musical models relate physical properties of stimuli to internal representations called features, and predictive models relate features to neural or behavioral responses and test their predictions against independent unseen data. The new frameworks do not require orthogonalized stimuli in controlled experiments to establish reproducible knowledge, which has opened up a new wave of naturalistic neuroscience. The current review focuses on how this trend has transformed the domain of the neuroscience of music.

Audience Interbrain Synchrony During Live Music Is Shaped by Both the Number of People Sharing Pleasure and the Strength of This Pleasure

The study of interbrain coupling in a group of people attending a concert together is a favorable framework to estimate group emotions and more precisely emotional connection between people sharing situations in the same environment. It offers the advantage of studying interactions at the group level. By recording the cerebral activity of people from an audience during a concert using electroencephalography, we previously demonstrated that the higher the emotions and the physically closer the people were, the more the interbrain synchrony (IBS) was enhanced. To further investigate the parameters that shaped inter-brain synchronization in this context, we now focus on the emotional dynamics of the group as a whole by identifying specific moments in the concert that evoked strong or weak emotions, as well as strong or weak emotional cohesion between individuals. We demonstrated that audience interbrain synchrony is mainly associated with experiencing high musical pleasure and that the group emotional cohesion can enhance IBS, but alone is not the major parameter that shapes it in this context.

Associations Between Sympathetic Nervous System Synchrony, Movement Synchrony, and Speech in Couple Therapy

Background

Research on interpersonal synchrony has mostly focused on a single modality, and hence little is known about the connections between different types of social attunement. In this study, the relationship between sympathetic nervous system synchrony, movement synchrony, and the amount of speech were studied in couple therapy.

Methods

Data comprised 12 couple therapy cases (24 clients and 10 therapists working in pairs as co-therapists). Synchrony in electrodermal activity, head and body movement, and the amount of speech and simultaneous speech during the sessions were analyzed in 12 sessions at the start of couple therapy (all 72 dyads) and eight sessions at the end of therapy (48 dyads). Synchrony was calculated from cross-correlations using time lags and compared to segment-shuffled pseudo synchrony. The associations between the synchrony modalities and speech were analyzed using complex modeling (Mplus).

Findings

Couple therapy participants' synchrony mostly occurred in-phase (positive synchrony). Anti-phase (negative) synchrony was more common in movement than in sympathetic nervous system activity. Synchrony in sympathetic nervous system activity only correlated with movement synchrony between the client-therapist dyads (r = 0.66 body synchrony, r = 0.59 head synchrony). Movement synchrony and the amount of speech correlated negatively between spouses (r = -0.62 body synchrony, r = -0.47 head synchrony) and co-therapists (r = -0.39 body synchrony, r = -0.28 head synchrony), meaning that the more time the dyad members talked during the session, the less bodily synchrony they exhibited.

Conclusion

The different roles and relationships in couple therapy were associated with the extent to which synchrony modalities were linked with each other. In the relationship between clients and therapists, synchrony in arousal levels and movement "walked hand in hand", whereas in the other relationships (spouse or colleague) they were not linked. Generally, more talk time by the therapy participants was associated with anti-phase movement synchrony. If, as suggested, emotions prepare us for motor action, an important finding of this study is that sympathetic nervous system activity can also synchronize with that of others independently of motor action.