Context-based signal descriptors of heart-rate variability for anxiety assessment

In this paper, we investigate the role of multiple context-based heart-rate variability descriptors for evaluating a person's psychological health, specifically anxiety disorders. The descriptors are extracted from visually sensed heart-rate signals obtained during the course of a semi-structured interview with a virtual human and can potentially integrate question context as well. The proposed descriptors are motivated by prior related work and are constructed based on histogram-based approaches, time and frequency domain analysis of heart-rate variability. In order to contextualize our descriptors, we use information about the polarity and intimacy levels of the questions asked. Our experiments reveal that the descriptors, both with and without context, perform far better than chance in predicting anxiety. Further on, we perform at-a-par with the state-of-the-art in predicting anxiety and other psychological disorders when we integrate the question context information into the descriptors.