Synchrony in therapist's and patient's vocally encoded arousal and its association with the quality of the therapeutic relationship.

Abstract

Objective: Therapeutic relationship is a core element of brief motivational intervention (bMI). Behavioral coding is the gold standard for capturing relational factors, but it is highly time-consuming. We aimed to examine the association between vocal arousal synchrony and the quality of the therapeutic relationship.

Method: This secondary analysis used 135 audio-recorded alcohol bMIs among French-speaking young adults (18-35 y.) from a randomized controlled trial. bMIs were categorized into higher and lower levels of therapist empathy, collaboration, therapeutic alliance and patient's perspective. The therapist's and patient's mean fundamental frequency of the voice (mean ƒ0) was extracted at 0.25-second intervals. Mean ƒ0 synchrony was computed at session- and minute-levels using Bayesian multilevel multivariate models and compared to higher- vs. lower-rated sessions.

Results: Higher-therapist empathy and higher-therapeutic alliance sessions showed medium-to-large mean ƒ0 synchrony while lower-rated sessions showed lower nonsignificant synchrony. However, differences in the degree of synchrony between higher- and lower-rated sessions were medium-to-large but nonsignificant. We found no evidence for mean ƒ0 synchrony at the minute-level for both measures, nor at all levels for therapist collaboration and the patient's perspective.

Conclusion: While the findings provide partial support for this paralinguistic feature modeling the therapist's relational skills, further research should examine under which conditions synchrony may predict relational factors.