Thermoregulatory variations following modulation of body part ownership through mirror-box illusion

The mirror box plays an important role in rehabilitation of patients with motor and ownership diseases. In this study, we implemented this tool with healthy participants in order to induce in them embodiment sensations related to the hand in the mirror, mimicking patients with disownership of their limb. This work takes into consideration the implicit and explicit feelings of ownership just after the tasks conducted, the homeostatic changes following the illusion and their correlation with interoceptive signals. So far, results from the literature appear to be controversial. The Mirror box illusion, respect to the more utilized Rubber hand illusion, seems to be a more complex and complete means for proving multisensory interaction between visual, tactile, interoceptive, proprioceptive, motor and homeostatic components. In conclusion, we found that healthy participants usually perceived the embodiment illusion both in an explicit and implicit way and that, when they perceived it, they underwent a significant drop in temperature of both limbs correlated with the strength of the illusion. Moreover, our results showed a role for interoception, indeed when the heartbeat detection task score was higher, the subjects used to experience stronger implicit illusion of ownership over the hand reflected in the mirror. Our results support the idea that the Mirror box illusion has the capacity to induce disownership of one’s own upper body part in healthy participants, leading to a temperature drop in both limbs, a process which can be modulated by interoceptive skills.