“Atypical touch perception in MTS may derive from an abnormally plastic self-representation”

Visual perspective and body ownership modulate vicarious pain and touch: A systematic review

We conducted a systematic review investigating the influence of visual perspective and body ownership (BO) on vicarious brain resonance and vicarious sensations during the observation of pain and touch. Indeed, the way in which brain reactivity and the phenomenological experience can be modulated by blurring the bodily boundaries of self-other distinction is still unclear. We screened Scopus and WebOfScience, and identified 31 articles, published from 2000 to 2022. Results show that assuming an egocentric perspective enhances vicarious resonance and vicarious sensations. Studies on synaesthetes suggest that vicarious conscious experiences are associated with an increased tendency to embody fake body parts, even in the absence of congruent multisensory stimulation. Moreover, immersive virtual reality studies show that the type of embodied virtual body can affect high-order sensations such as appropriateness, unpleasantness, and erogeneity, associated with the touched body part and the toucher's social identity. We conclude that perspective plays a key role in the resonance with others' pain and touch, and full-BO over virtual avatars allows investigation of complex aspects of pain and touch perception which would not be possible in reality.

From mirror-touch synesthesia to models of vicarious experience: A reply to commentaries

In this reply to the eight commentaries to our article, we discuss three important challenges. First, we discuss the relationship of mirror-touch to other forms of synesthesia. We note that synesthetic experiences are generally not mistaken as veridical but this does not mean that they lack percept-like qualities. We acknowledge that neither Threshold Theory nor Self-Other Theory offer a direct account of other forms of synesthesia, although we discuss how the latter could. Second, we discuss alternative explanations. Notably predictive coding offers a different way of framing our current theory, and extending it to related phenomena. Finally, we discuss how mirror-touch synesthesia may relate to other atypical experiences of body ownership such as the rubber hand illusion, and somatoparaphrenia.