Catching a (sine) wave: Temporal dynamics of nonverbal synchrony in social anxiety disorder.

Individuals with social anxiety disorder (SAD) experience a range of interpersonal problems and studies have found that nonverbal synchrony (the coordination between interaction partners' movements) may be impaired in dyads in which one individual has SAD (Asher et al., 2020). In the present study, we examined the temporal dynamics of nonverbal synchrony during "getting aquatinted" conversations of individuals with and without SAD. Specifically, participants (n = 146) formed either SAD dyads (dyads in which one individual had SAD and the other did not; n = 37 dyads), or control dyads (dyads in which both individuals did not have SAD; n = 36 dyads). Dyads were randomized to either small talk or closeness-generating (i.e., intimate) conversations. We found that during conversations, nonverbal synchrony followed a repeating pattern of increases and decreases that was best modeled by a sinusoidal wave (explained variance = 63.74 %). We found significant Diagnosis × Social Context interactions in the temporal dynamics of nonverbal synchrony (i.e., in the parameters of sine waves). Specifically, we found that for SAD dyads (but not control dyads), the average sine wave amplitude which indicates increases and decreases in nonverbal synchrony was greater during small talk conversations compared to closeness-generating conversations. In addition, we found that among control dyads (but not SAD dyads), the average vertical offset of sine waves (i.e., the average level of nonverbal synchrony) during closeness-generating conversations was greater compared to small talk conversations. The findings are interpreted within the context of the social anxiety literature as capturing two distinct social-anxiety related processes, and suggest that when examined temporally (rather than averaged), nonverbal synchrony may be an important implicit biomarker of SAD.

Exploring the evolution of nonverbal synchrony in psychotherapy: The idiographic perspective provides a different picture.

Objectives: 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.Methods: 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 N = 12 dyadic psychotherapies with a total of N = 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.Results: 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.Conclusions: 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.

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.

Nonverbal synchrony and affect in dyadic interactions.

In an experiment on dyadic social interaction, we invited participants to verbal interactions in cooperative, competitive, and 'fun task' conditions. We focused on the link between interactants' affectivity and their nonverbal synchrony, and explored which further variables contributed to affectivity: interactants' personality traits, sex, and the prescribed interaction tasks. Nonverbal synchrony was quantified by the coordination of interactants' body movement, using an automated video-analysis algorithm (motion energy analysis). Traits were assessed with standard questionnaires of personality, attachment, interactional style, psychopathology, and interpersonal reactivity. We included 168 previously unacquainted individuals who were randomly allocated to same-sex dyads (84 females, 84 males, mean age 27.8 years). Dyads discussed four topics of general interest drawn from an urn of eight topics, and finally engaged in a fun interaction. Each interaction lasted 5 min. In between interactions, participants repeatedly assessed their affect. Using hierarchical linear modeling, we found moderate to strong effect sizes for synchrony to occur, especially in competitive and fun task conditions. Positive affect was associated positively with synchrony, negative affect was associated negatively. As for causal direction, data supported the interpretation that synchrony entailed affect rather than vice versa. The link between nonverbal synchrony and affect was strongest in female dyads. The findings extend previous reports of synchrony and mimicry associated with emotion in relationships and suggest a possible mechanism of the synchrony-affect correlation.