Sync pending: Characterizing conversational entrainment in dysarthria using a multidimensional, clinically informed approach

Purpose: Despite the import of conversational entrainment to successful spoken dialogue, the systematic characterization of this behavioral syncing phenomenon represents a critical gap in the field of speech pathology. The goal of this study was to acoustically characterize conversational entrainment in the context of dysarthria using a multidimensional approach previously validated in healthy populations (healthy conversations; Borrie, Barrett, Willi, & Berisha, 2019). Method: A large corpus of goal-oriented conversations between participants with dysarthria and healthy participants (disordered conversations) was elicited using a “spot the difference” task. Expert clinical assessment of entrainment and a measure of conversational success (communicative efficiency) was obtained for each of the audio-recorded conversations. Conversational entrainment of acoustic features representing rhythmic, articulatory, and phonatory dimensions of speech was identified using cross-recurrence quantification analysis with clinically informed model parameters and validated with a sham condition involving conversational participants who did not converse with one another. The relationship between conversational entrainment and communicative efficiency was examined. Results: Acoustic evidence of entrainment was observed in phonatory, but not rhythmic and articulatory, behavior, a finding that differs from healthy conversations in which entrainment was observed in all speech signal dimensions. This result, that disordered conversations showed less acoustic entrainment than healthy conversations, is corroborated by clinical assessment of entrainment in which the disordered conversations were rated, overall, as being less in sync than healthy conversations. Furthermore, acoustic entrainment was predictive of communicative efficiency, corroborated by a relationship between clinical assessment and the same outcome measure. Conclusions: The findings confirm our hypothesis that the pathological speech production parameters of dysarthria disrupt the seemingly ubiquitous phenomenon of conversational entrainment, thus advancing entrainment deficits as an important variable in dysarthria, one that may have causative effects on the success of everyday communication. Results further reveal that while this approach provides a broad overview, methodologies for characterizing conversational entrainment in dysarthria must continue to be developed and refined, with a focus on clinical utility.