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.

Long-term psychodynamic psychotherapy in a face-to-face versus videoconferencing setting: A single case study.

OBJECTIVE: Due to the coronavirus pandemic and crisis, psychotherapists around the world were forced to switch to video- or tele-based treatments overnight. To date, only a few studies on the effectiveness of video-based psychodynamic psychotherapy via the Internet exist. Therefore, the goal of the present study was to examine symptom improvement, therapeutic relationship, nonverbal synchrony processes, and intersession processes within a systematic single case design and compare face-to-face to video-based approaches in long-term psychodynamic-oriented psychotherapy. METHODS: We examined 85 sessions of a client with major depression whose psychodynamic psychotherapy changed from a face-to-face setting to a video-based setting. Video recordings were analyzed using motion energy analysis, and nonverbal synchrony was computed using a surrogate synchrony approach. Time series analyses were performed to analyze changes in symptom severity, therapeutic relationship, and intersession processes. RESULTS: The results showed that symptom severity improved descriptively, but not significantly, across the entire course of psychotherapy. There were significant differences, however, in the therapeutic relationship, intersession experiences, and synchronous behavior between the face-to-face and video-based settings. CONCLUSION: The results indicate that the presented methodology is well situated to investigate the question whether psychodynamic psychotherapy in video-based setting works in the sameway as in a face-to-face setting.

Growth curves of common factors in psychotherapy: Multilevel growth modelling and outcome analysis.

OBJECTIVE: A large body of literature discusses change mechanisms underlying psychotherapy with an emphasis on common factors. The present study examined how different comprehensive common factors change over the course of therapy and whether this change was associated with clinical outcome at discharge. METHOD: Three hundred forty-eight adults (mean age = 32.1, SD = 10.6; 64% female) attended a standardized 14-week day-clinic psychotherapy program. They provided longitudinal data on common factors based on weekly assessments. Additionally, pre- and post-assessment questionnaires on clinical outcome were completed. Using multilevel modelling, we predicted common factors by time (week in therapy). Multiple linear regression models tested the association between changes in common factors and clinical outcome. RESULTS: The common factor 'Therapeutic Alliance' was best fitted by linear growth models, whereas models for the common factors 'Coping', 'Cognitive Integration' and 'Affective Processing' indicated logarithmic changes over time. 'Coping', that is change in patients' ability to cope with their individual problems, was most closely linked with outcome. CONCLUSIONS: The present study provides evidence for the changeability of common factors over the course of therapy as well as their specific contributions to psychotherapeutic progress.

Electrodermal and respiratory synchrony in couple therapy in distinct therapeutic subsystems and reflection periods.

Objective Synchrony in the multi-person context of systemic therapy is a complex and understudied phenomenon. We analyzed respiratory and electrodermal synchronies within a couple therapy system with two therapists to determine whether dyadic subsystems between each client and therapist synchronized differently. We also studied synchrony in reflection periods, in which the therapists discussed the therapy process with clients listening. Finally, we examined the association of synchronies with alliance and outcome.Method: A sample of 22 therapy sessions in which electrodermal activity (EDA) and respiration were recorded were analyzed. Self-report measures of session alliance and outcome were obtained. Synchrony computation was based on windowed cross-correlation using surrogate synchrony and segment-wise shuffling of physiological time series.Results: The results supported the presence of EDA synchrony for the client-therapist and therapist-therapist dyads but not client-client dyads across entire sessions. No significant synchronies were found for respiration behavior. A similar picture was found in reflection periods. Clients' well-being as well as therapists' alliance ratings were significant predictors of client-client EDA synchrony.Conclusion: Our results point to the relational meaning of synchrony and its importance for understanding couple psychotherapy, particularly the reflection periods. Challenges involved in extending synchrony computation to multi-person settings were highlighted.

A Complexity Science Account of Humor.

A common assumption of psychological theories of humor is that experienced funniness results from an incongruity between stimuli provided by a verbal joke or visual pun, followed by a sudden, surprising resolution of incongruity. In the perspective of complexity science, this characteristic incongruity-resolution sequence is modeled by a phase transition, where an initial attractor-like script, suggested by the initial joke information, is suddenly destructed, and in the course of resolution replaced by a less probable novel script. The transition from the initial to the enforced final script was modeled as a succession of two attractors with different minimum potentials, during which free energy becomes available to the joke recipient. Hypotheses derived from the model were tested in an empirical study where participants rated the funniness of visual puns. It was found, consistent with the model, that the extent of incongruity and the abruptness of resolution were associated with reported funniness, and with social factors, such as disparagement (Schadenfreude) added to humor responses. The model suggests explanations as to why bistable puns and phase transitions in conventional problem solving, albeit also based on phase transitions, are generally less funny. We proposed that findings from the model can be transferred to decision processes and mental change dynamics in psychotherapy.

Complexity Science in Human Change: Research, Models, Clinical Applications.

Complexity and entropy prevail in human behavior and social interaction because the systems underlying behavior and interaction are, without a doubt, highly complex [...].

Cross-Correlation- and Entropy-Based Measures of Movement Synchrony: Non-Convergence of Measures Leads to Different Associations with Depressive Symptoms.

BACKGROUND: Several algorithms have been proposed to quantify synchronization. However, little is known about their convergent and predictive validity. METHODS: The sample included 30 persons who completed a manualized interview focusing on psychosomatic symptoms. The intensity of body motions was measured using motion-energy analysis. We computed several measures of movement synchrony based on the time series of the interviewer and participant: mutual information, windowed cross-recurrence analysis, cross-correlation, rMEA, SUSY, SUCO, WCLC-PP and WCLR-PP. Depressive symptoms were assessed with the Patient Health Questionnaire (PHQ9). RESULTS: According to the explorative factor analyses, all the variants of cross-correlation and all the measures of SUSY, SUCO and rMEA-WCC led to similar synchrony measures and could be assigned to the same factor. All the mutual-information measures, rMEA-WCLC, WCLC-PP-F, WCLC-PP-R2, WCLR-PP-F, and WinCRQA-DET loaded on the second factor. Depressive symptoms correlated negatively with WCLC-PP-F and WCLR-PP-F and positively with rMEA-WCC, SUCO-ES-CO, and MI-Z. CONCLUSION: More standardization efforts are needed because different synchrony measures have little convergent validity, which can lead to contradictory conclusions concerning associations between depressive symptoms and movement synchrony using the same dataset.

Affect-Logic, Embodiment, Synergetics, and the Free Energy Principle: New Approaches to the Understanding and Treatment of Schizophrenia.

This theoretical paper explores the affect-logic approach to schizophrenia in light of the general complexity theories of cognition: embodied cognition, Haken's synergetics, and Friston's free energy principle. According to affect-logic, the mental apparatus is an embodied system open to its environment, driven by bioenergetic inputs of emotions. Emotions are rooted in goal-directed embodied states selected by evolutionary pressure for coping with specific situations such as fight, flight, attachment, and others. According to synergetics, nonlinear bifurcations and the emergence of new global patterns occur in open systems when control parameters reach a critical level. Applied to the emergence of psychotic states, synergetics and the proposed energetic understanding of emotions lead to the hypothesis that critical levels of emotional tension may be responsible for the transition from normal to psychotic modes of functioning in vulnerable individuals. In addition, the free energy principle through learning suggests that psychotic symptoms correspond to alternative modes of minimizing free energy, which then entails distorted perceptions of the body, self, and reality. This synthetic formulation has implications for novel therapeutic and preventive strategies in the treatment of psychoses, among these are milieu-therapeutic approaches of the Soteria type that focus on a sustained reduction of emotional tension and phenomenologically oriented methods for improving the perception of body, self, and reality.

Beyond Dyadic Coupling: The Method of Multivariate Surrogate Synchrony (mv-SUSY).

Measuring interpersonal synchrony is a promising approach to assess the complexity of social interaction, which however has been mostly limited to dyads. In this study, we introduce multivariate Surrogate Synchrony (mv-SUSY) to extend the current set of computational methods. Methods: mv-SUSY was applied to eight datasets consisting of 10 time series each, all with n = 9600 observations. Datasets 1 to 5 consist of simulated time series with the following characteristics: white noise (dataset 1), non-stationarity with linear time trends (dataset 2), autocorrelation (dataset 3), oscillation (dataset 4), and multivariate correlation (dataset 5). Datasets 6 to 8 comprise empirical multivariate movement data of two individuals (datasets 6 and 7) and between members of a group discussion (dataset 8.) Results: As hypothesized, findings of mv-SUSY revealed absence of synchrony in datasets 1 to 4 and presence of synchrony in dataset 5. In the empirical datasets, mv-SUSY indicated significant movement synchrony. These results were predominantly replicated by two well-established dyadic synchrony approaches, Surrogate Synchrony (SUSY) and Surrogate Concordance (SUCO). Conclusions: The study applied and evaluated a novel synchrony approach, mv-SUSY. We demonstrated the feasibility and validity of estimating multivariate nonverbal synchrony within and between individuals by mv-SUSY.

Eye Synchrony: A Method to Capture Mutual and Joint Attention in Social Eye Movements.

Gaze behavior represents a complex phenomenon in social inter-action. We focus here on dyadic face-to-face interaction during naturally occurring verbal exchanges, where shared attention can be operationalized by joint gazes and eye contact. A multi-step methodology for the analysis of eye synchrony is presented, exemplified by a single case. The dynamics of face-to-face interaction allows estimating the degree of interlocutors' synchrony. While there is growing evidence for interpersonal synchrony of various behavioral and physiological signals, eye synchrony has not yet been studied outside the laboratory. The method presented is based on time series of gaze behavior acquired by mobile eye tracking devices. We applied windowed cross-correlations to the data and used surrogate testing to attain effect sizes even for single interactions (Surrogate Synchrony, SUSY). SUSY thus integrates nomo-thetic with idiographic research goals: The nomothetic interest is to test hypotheses that gaze behavior may be generally synchronized and linked with psychological variables. The idiographic aspect is that effect sizes can be determined even in single-case studies owing to the surrogate analyses, which supports qualitative research. Results of the exemplary dataset suggested that proof-of-concept of this approach was attained. We describe what prerequisites are needed of a setting and technical setup for use in future studies of psychotherapy, counseling, negotiations, or work-related interactions.

Exploring nonverbal synchrony in borderline personality disorder: A double-blind placebo-controlled study using oxytocin.

OBJECTIVES: Interpersonal dysfunction is a central feature of borderline personality disorder (BPD), and the neuropeptide oxytocin (OT) has been shown to impact patients' behaviour in numerous ways. Nonverbal signals such as the coordination of body movement (nonverbal synchrony) are associated with the success of interpersonal exchanges and could thus be influenced by features of BPD and by the administration of OT. DESIGN: We explored the effect of intranasal OT (inOT) on nonverbal synchrony in sixteen patients with BPD and fifteen healthy controls (CTL) randomly assigned to two double-blind clinical interviews under inOT and placebo (PL). METHODS: Nonverbal synchrony was assessed by automated video-analyses of subject's and interviewer's body movement. Lagged cross-correlations were used to objectively quantify coordination in dyads. RESULTS: Synchrony was higher than pseudosynchrony (= synchrony expected by chance), and there was a differential effect of inOT between groups: While healthy controls displayed increased synchrony under inOT, patients with BPD showed low levels of synchrony under inOT. Additionally, patient's synchrony was negatively associated with self-reported childhood trauma. CONCLUSIONS: Nonverbal synchrony in clinical interviews is influenced by inOT, and this effect depends on subject's diagnosis. In line with previous research implying positive associations between nonverbal synchrony and relationship quality, inOT led to an increase of synchrony in healthy controls, but not in patients with BPD. Low levels of synchrony under inOT in patients and its association with childhood trauma suggest that additional mechanisms such as rejection sensitivity might mediate BPD patients' nonverbal behaviour. PRACTITIONER POINTS: Intranasal oxytocin (inOT) attenuated nonverbal synchrony - a proxy for relationship quality - in patients with borderline personality disorder (BPD), while it increased nonverbal synchrony in healthy controls (CTL). Available models (rejection sensitivity; social salience) suggest that inOT may alter the way patients with BPD assess social situations, and this alteration is expressed by changes in nonverbal coordination. Patients with BPD display low levels of synchrony which are even below expected pseudosynchrony based on chance. The association between self-reported childhood trauma and lower synchrony in BPD was most evident for patient's imitative behaviour: Under inOT, patients with high scores of childhood trauma refrained from imitating their interview partners. Study limitations include small sample sizes and limited data on the psychological impact of the clinical interviews.

Physiological synchrony in psychotherapy sessions.

Objective: 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. Methods: 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. Results: 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. Conclusions: 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.

Causation and chance: Detection of deterministic and stochastic ingredients in psychotherapy processes.

A novel methodology for the empirical analysis of processes in psychotherapy was developed and tested. This method is based on the Fokker-Planck equation (FPE), a probabilistic model that detects the deterministic and stochastic components of a process. The deterministic component is given by the potential function underlying the process. The FPE application can be used to visualize the attractor (or in the case of multistability, attractors) of the dynamics, and the sources of stochasticity. The FPE app can also be employed in two-dimensional systems, for example, client's and therapist's coupled processes; then the method is run on the cross-correlations of the time series. Signatures were defined that merge the functions retrieved from the methodology into numerical values, and may serve to detect associations with conventional self-report measures of psychotherapy. The method was tested in a case series where client's and therapist's heart rate, heart rate variability and respiration were monitored in 20 psychotherapy sessions. The FPE app works well with time series of high resolution and adequate observation numbers, which renders it applicable to nonverbal and physiological time series.

Dynamic dyadic processes in psychotherapy: Introduction to a special section.

There is a growing consensus among psychotherapy theoreticians and researchers that psychotherapy processes are an interpersonal phenomenon that can be studied as a dynamic system. The aim of this special section is to highlight the importance of exploring the complex processes that emerge over time from interactions and feedback loops amongst sub-components (e.g., emotions, non-verbal behavior, physiology, voice, subjective experience) within and between clients and therapists. The articles featured in this special section discuss multiple methods and angles to study dynamic dyadic processes in psychotherapy that can better capture the complexity of the therapeutic process and the ways it can lead to favorable outcomes. Future research that focuses on dynamic dyadic processes in psychotherapy is outlined.

Psychophysiological Synchrony During Verbal Interaction in Romantic Relationships.

Previous studies about romantic relationships have shown that the reciprocal influence between partners occurs not only at the behavioral and socio-emotional levels, but also at the psychophysiological level. This reciprocal influence is expressed in a pattern of physiological synchrony between partners (i.e., coordinated dynamics of the physiological time series). The main aim of the present study was to explore the presence of a pattern of physiological synchrony in electrodermal activity (EDA) during a couple interaction task. A second objective was to compare the synchrony levels during a negative interaction condition versus a positive interaction condition. Finally, we analyzed the association between synchrony and self-perception of empathy, dyadic empathy, and relationship satisfaction. Thirty-two couples (64 individuals) participated in this study. Each couple performed a structured interaction task while the EDA of both partners was being registered. The quantification of synchrony was based on the cross-correlation of both members' EDA time-series. In order to control for coincidental synchrony, surrogate datasets were created by repeatedly shuffling the original data of spouses X and Y of a dyad and computing synchronies on the basis of the shuffled data (pseudosynchrony values). Our results confirmed the presence of significant EDA synchrony during the interaction. We also found that synchrony was higher during the negative interactions relative to the positive interactions. Additionally, physiological synchrony during positive interaction was higher for those couples in which males scored higher in dyadic empathy. The clinical implications of these findings are discussed.

Estudios anteriores acerca de las relaciones amorosas han demostrado que la influencia recíproca entre las parejas no solo ocurre en los niveles conductuales y socioemocionales, sino también en el nivel psicofisiológico. Esta influencia recíproca se expresa en un patrón de sincronía fisiológica entre los integrantes de la pareja (p. ej.: la dinámica coordinada de las series temporales fisiológicas). El objetivo principal del presente estudio fue analizar la presencia de un patrón de sincronía fisiológica en la actividad electrodérmica (AED) durante una tarea de interacción de la pareja. Un segundo objetivo fue comparar los niveles de sincronía durante una situación de interacción negativa frente a una situación de interacción positiva. Finalmente, analizamos la asociación entre la sincronía y la autopercepción de empatía, la empatía diádica y la satisfacción con la relación. Treinta y dos parejas (64 personas) participaron en este estudio. Cada pareja llevó a cabo una tarea de interacción estructurada mientras se registraba la AED de ambos integrantes de la pareja. La cuantificación de la sincronía se basó en la correlación cruzada de las series temporales de la AED de ambos miembros. A fin de controlar la sincronía simultánea, se crearon conjuntos de datos sustitutos entremezclando continuamente los datos originales de los cónyuges X e Y de una díada y computando las sincronías sobre la base de los datos mezclados (valores de seudosincronía). Nuestros resultados confirmaron la presencia de una sincronía considerable de la AED durante la interacción. También descubrimos que la sincronía fue mayor durante las interacciones negativas respecto de las interacciones positivas. Además, la sincronía fisiológica durante la interacción positiva fue mayor en aquellas parejas en las cuales los hombres obtuvieron un puntaje más alto en la empatía diádica. Se debaten las consencuencias clínicas de estos resultados.

Sharing the Now in the Social Present: Duration of Nonverbal Synchrony Is Linked With Personality.

OBJECTIVE: The social present is a novel descriptor of dyadic nowness and social sharing, extending research on individual nowness (James's [1890] specious present) to the interpersonal and intersubjective domain. We wished to connect this descriptor to personality attributes. METHOD: We define the social present by the duration of significant nonverbal synchrony, based on the phenomenon of movement synchrony that generally emerges in social interactions. It is thus an implicit and objective measure that can be implemented by automated video analyses. In this study, 168 healthy participants were invited to verbal conversations in same-sex dyads. We analyzed the associations of the social present with personality attributes and interaction types (competition, cooperation, fun task). RESULTS: The average duration of the social present was 6.0 seconds, highest in competitive interactions and in male-male dyads. People with higher Openness to Experience, higher avoidant attachment, and lower narcissistic interpersonal styles showed extended social present in their interactions. CONCLUSIONS: The concept of the social present extends personality attributes to the interpersonal domain and to intersubjectivity. The social present may be computed based on movement synchrony but also prosodic or physiological synchronies. We foresee implications for health-related interactions such as psychotherapy, where therapeutic presence is an essential property of alliance.

How to Modify Psychopathological States? Hypotheses Based on Complex Systems Theory.

In mathematical analysis based on the assumptions of complexity science, the emergence of a pattern is the result of a competition of modes, which each have a parameter value attached. In the context of visual pattern recognition, a specific connectionist system (the synergetic computer SC) was developed, which was derived from the assumptions of synergetics, a theory of complex systems. We adapted the processes of visual pattern recognition performed by the SC to a different context, psychopathology and therapeutic interventions, assuming these scenarios are analogous. The problem then becomes, under which conditions will a previously established psychopathological pattern not be restituted? We discuss several cases by using the equations of the SC. Translated to the psychopathological context, we interpret the mathematical findings and proofs in such a way that successful corrective interventions, e.g. by psychotherapy, should focus on one alternative pattern only. This alternative cognition-behavior-experience pattern is to be constructed individually by a therapist and a patient in the therapeutic alliance. The alternative pattern must be provided with higher valence (i.e. affective and motivational intensity) than possessed by the psychopathological pattern. Our findings do not support a linear symptom-oriented therapy approach based on specific intervention techniques, but rather a holistic approach. This is consistent with empirical results of psychotherapy research, especially the theory of common factors.

Movement Coordination in Psychotherapy: Synchrony of Hand Movements is Associated with Session Outcome. A Single-Case Study.

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.

Towards a taxonomy of common factors in psychotherapy-results of an expert survey.

BACKGROUND: How change comes about is hotly debated in psychotherapy research. One camp considers 'non-specific' or 'common factors', shared by different therapy approaches, as essential, whereas researchers of the other camp consider specific techniques as the essential ingredients of change. This controversy, however, suffers from unclear terminology and logical inconsistencies. The Taxonomy Project therefore aims at contributing to the definition and conceptualization of common factors of psychotherapy by analyzing their differential associations to standard techniques. METHODS: A review identified 22 common factors discussed in psychotherapy research literature. We conducted a survey, in which 68 psychotherapy experts assessed how common factors are implemented by specific techniques. Using hierarchical linear models, we predicted each common factor by techniques and by experts' age, gender and allegiance to a therapy orientation. RESULTS: Common factors differed largely in their relevance for technique implementation. Patient engagement, Affective experiencing and Therapeutic alliance were judged most relevant. Common factors also differed with respect to how well they could be explained by the set of techniques. We present detailed profiles of all common factors by the (positively or negatively) associated techniques. There were indications of a biased taxonomy not covering the embodiment of psychotherapy (expressed by body-centred techniques such as progressive muscle relaxation, biofeedback training and hypnosis). Likewise, common factors did not adequately represent effective psychodynamic and systemic techniques. CONCLUSION: This taxonomic endeavour is a step towards a clarification of important core constructs of psychotherapy. KEY PRACTITIONER MESSAGE: This article relates standard techniques of psychotherapy (well known to practising therapists) to the change factors/change mechanisms discussed in psychotherapy theory. It gives a short review of the current debate on the mechanisms by which psychotherapy works. We provide detailed profiles of change mechanisms and how they may be generated by practice techniques.

The pairwise approximate spatiotemporal symmetry algorithm: A method for segmenting time series pairs.

Methods that measure the association between two intensively measured time series are of interest to researchers studying the symmetry of behaviors during social interaction. Such methods have historically focused on aggregating the amount of symmetry across all measurement occasions. However, it is rarely expected that symmetry is present at all measurement occasions. The current method, the pairwise approximate spatiotemporal symmetry (PASS) algorithm, is an approach that may be used to determine which measurement occasions in pairwise time series are indicative of symmetry and which are not. This process thus divides time series into symmetric and nonsymmetric segments. The PASS algorithm is demonstrated here on representative simulated data and naturalistic psychotherapy data. Results suggest that the PASS algorithm has the potential to extract meaningful symmetry segments from human signals. (PsycInfo Database Record (c) 2024 APA, all rights reserved).