Characteristics of vicarious touch reports in a general population.

Vicarious touch broadly refers to sensory, neural, or affective responses to observing touch on another person. In this study, we focused on the conscious experience of these sensations. We collected vicarious touch reports from 422 undergraduate students who viewed videos from the validated touch-video database (VTD), a stimulus set systematically rated for hedonic qualities, arousal, and perceived threat levels. A surprisingly large majority (84%) of participants reported vicarious sensations such as touch, tingling, pressure, and pain, predominantly matched to the location of touch on the hands observed in the videos. Contrary to previous studies, we found that vicarious touch was more prevalent in women than men. Additionally, while earlier research suggested a correlation between vicarious sensations and emotional reactivity, our data did not support this relationship. The nature and intensity of reported sensations varied strongly with the emotional content of the videos: pleasant touches often evoked ticklish or warm sensations, while unpleasant touches often resulted in pain or pressure. Participants regularly described their sensations as either pleasant or unpleasant, indicating that the affective qualities of observed touch were mirrored in their experiences. Subjective arousal and threat ratings taken from the VTD for each video strongly correlated with the prevalence and intensity of vicarious touch measured here, with painful, highly arousing touches eliciting the strongest responses. Even observing touch on a non-human object occasionally triggered similar vicarious sensations. Using a new clustering approach, we identified three distinct profiles of vicarious touch, each characterised by unique sensory experiences, variations in the localisation and intensity of sensations, and differences in responses to observing touch on another person versus an object. Overall, our results challenge the traditional view that conscious vicarious touch experiences are a rare phenomenon and underscore the diversity of vicarious sensory perception.