Representation Learning for Interpersonal and Multimodal Behavior Dynamics: A Multiview Extension of Latent Change Score Models.

Characterizing the dynamics of behavior across multiple modalities and individuals is a vital component of computational behavior analysis. This is especially important in certain applications, such as psychotherapy, where individualized tracking of behavior patterns can provide valuable information about the patient's mental state. Conventional methods that rely on aggregate statistics and correlational metrics may not always suffice, as they are often unable to capture causal relationships or evaluate the true probability of identified patterns. To address these challenges, we present a novel approach to learning multimodal and interpersonal representations of behavior dynamics during one-on-one interaction. Our approach is enabled by the introduction of a multiview extension of latent change score models, which facilitates the concurrent capture of both inter-modal and interpersonal behavior dynamics and the identification of directional relationships between them. A core advantage of our approach is its high level of interpretability while simultaneously achieving strong predictive performance. We evaluate our approach within the domain of therapist-client interactions, with the objective of gaining a deeper understanding about the collaborative relationship between the two, a crucial element of the therapeutic process. Our results demonstrate improved performance over conventional approaches that rely upon summary statistics or correlational metrics. Furthermore, since our multiview approach includes the explicit modeling of uncertainty, it naturally lends itself to integration with probabilistic classifiers, such as Gaussian process models. We demonstrate that this integration leads to even further improved performance, all the while maintaining highly interpretable qualities. Our analysis provides compelling motivation for further exploration of stochastic systems within computational models of behavior.