Vicarious pain while observing another in pain:an experimental approach

Objective: This study aimed at developing an experimental paradigm to assess vicarious pain experiences. We further explored the putative moderating role of observer's characteristics such as hypervigilance for pain and dispositional empathy. Methods: Two experiments are reported using a similar procedure. Undergraduate students were selected based upon whether they reported vicarious pain in daily life, and categorized into a pain responder group or a comparison group. Participants were presented a series of videos showing hands being pricked whilst receiving occasionally pricking (electrocutaneous) stimuli themselves. In congruent trials, pricking and visual stimuli were applied to the same spatial location. In incongruent trials, pricking and visual stimuli were in the opposite spatial location. Participants were required to report on which location they felt a pricking sensation. Of primary interest was the effect of viewing another in pain upon vicarious pain errors, i.e., the number of trials in which an illusionary sensation was reported. Furthermore, we explored the effect of individual differences in hypervigilance to pain, dispositional empathy and the rubber hand illusion (RHI) upon vicarious pain errors. Results: Results of both experiments indicated that the number of vicarious pain errors was overall low. In line with expectations, the number of vicarious pain errors was higher in the pain responder group than in the comparison group. Self-reported hypervigilance for pain lowered the probability of reporting vicarious pain errors in the pain responder group, but dispositional empathy and the RHI did not. Conclusion: Our paradigm allows measuring vicarious pain experiences in students. However, the prevalence of vicarious experiences of pain is low, and only a small percentage of participants display the phenomenon. It remains however unknown which variables affect its occurrence

Visuo-motor adaptation and bodily representations: From neglect to complex regional pain syndrome

This publication is an invited topical review that summarizes the recent findings regarding the neglect-like symptoms observed in patients with complex regional pain syndrome (CRPS). Some of these patients tend to ignore or have an altered mental representation of the affected limb. CRPS include bodily schema and image alterations and reflect a potential top-down effect of visuo-spatial attention on somesthesic and nociceptive integration, linked to a directed hyperattention. Prismatic adaptation could act not only on bodily schema through visuo-spatial attention change, but also on pain and motricity. This opens potential therapeutic perspectives bypassing higher cognitive levels and especially consciousness and intentional control