Touching the unseen: Exploring affective responses to haptic stimuli with and without visual input

The sense of touch is fundamental to human experience, influencing emotions, behaviors, and social interactions. While previous studies on texture and emotion have focused on the precise discrimination of tactile stimuli, the emotional aspects have been less explored. In this study, we reanalyzed data from a previously published study to map haptic and visuo-haptic stimuli onto a two-dimensional affective space of valence and arousal and to compare the affective representations of unimodal and bimodal stimuli. We used multivariate methods, including multidimensional scaling and classification, to explore whether the affective dimensions of haptic and visuo-haptic stimuli support core affect theory and whether they share affective representations. The results of multidimensional scaling indicated that the roughness and hardness dimensions corresponded to valence and arousal, supporting core affect theory. Within-condition classification analyses indicated that both haptic and visuo-haptic stimuli could be predicted by tactile and emotion scales. Cross-condition classification revealed that the roughness and hardness of tactile stimuli could be accurately predicted from tactile and emotional ratings of visuo-haptic stimuli, and vice versa. These findings provide empirical evidence for a modality-general representation of affective and haptic responses, highlighting the interconnected nature of sensory and emotional experiences.