Multimodal Analysis and Assessment of Therapist Empathy in Motivational Interviews

The quality and effectiveness of psychotherapy sessions are highly influenced by the therapists' ability to meaningfully connect with clients. Automated assessment of therapist empathy provides cost-effective and systematic means of assessing the quality of therapy sessions. In this work, we propose to assess therapist empathy using multimodal behavioral data, i.e. spoken language (text) and audio in real-world motivational interviewing (MI) sessions for alcohol abuse intervention. We first study each modality (text vs. audio) individually and then evaluate a multimodal approach using different fusion strategies for automated recognition of empathy levels (high vs. low). Leveraging recent pre-trained models both for text (DistilRoBERTa) and speech (HuBERT) as strong unimodal baselines, we obtain consistent 2-3 point improvements in F1 scores with early and late fusion, and the highest absolute improvement of 6-12 points over unimodal baselines. Our models obtain F1 scores of 68% when only looking at an early segment of the sessions and up to 72% in a therapist-dependent setting. In addition, our results show that a relatively small portion of sessions, specifically the second quartile, is most important in empathy prediction, outperforming predictions on later segments and on the full sessions. Our analyses in late fusion results show that fusion models rely more on the audio modality in limited-data settings, such as in individual quartiles and when using only therapist turns. Further, we observe the highest misclassification rates for parts of the sessions with MI inconsistent utterances (20% misclassified by all models), likely due to the complex nature of these types of intents in relation to perceived empathy.