Towards a Haptic Taxonomy of Emotions: Exploring Vibrotactile Stimulation in the Dorsal Region

The implicit communication of emotional states between persons is a key use case for novel assistive and augmentation technologies. It can serve to expand individuals' perceptual capabilities and assist neurodivergent individuals. Notably, vibrotactile rendering is a promising method for delivering emotional information with minimal interference with visual or auditory perception. To date, the subjective individual association between vibrotactile properties and emotional states remains unclear. Previous approaches relied on analogies or arbitrary variations, limiting generalization. To address this, we conducted a study with 40 participants, analyzing associations between attributes of self-generated vibrotactile patterns (\textsc{amplitude}, \textsc{frequency}, \textsc{spatial location} of stimulation) and four emotional states (\textsc{Anger}, \textsc{Happiness}, \textsc{Neutral}, \textsc{Sadness}). We fin a preference for symmetrically arranged patterns, as well as distinct amplitude and frequency profiles for different emotions. These insights can aid in creating standardized vibrotactile patterns for universal emotional communication.