Virtual social touch on embodied avatars in patients with Fibromyalgia.

Fibromyalgia (FM) is a chronic pain syndrome, affecting quality of life and social functioning. Since social touch is crucial for personal relationships, we investigated how ‘vicarious’ social touch is perceived in FM using Virtual Reality (VR) and physiological recordings. Participants (FM and healthy controls) observed a female avatar in first-person perspective.24 virtual pleasant touches were delivered by another female avatar on 6 different body parts, previously categorized as neutral, social and intimate. Perceived appropriateness, pleasantness, erogeneity and ownership for the touched body part were collected (0-100 Visual Analogue Scales) after each stimulus. Skin Conductance Response and Heart Rate were recorded during each trial. Virtual touch on the intimate area was perceived as less appropriate, less pleasant but more erogenous as compared to the social and neutral one in both groups. FM reported higher perceived appropriateness, pleasantness and erogeneity. No differences emerged in ownership ratings. Although the qualitative evaluation of touch and ownership didn’t vary between the groups, FM ratings were higher, suggesting a generalized increased response to touch, while the hypothesis of anhedonia to gentle touch, at least for virtual stimuli, was not confirmed.