The role of pheripheral thermal regulation in Body-Self Awareness

The sense of body ownership, relying on the assumption that “E is embodied if and only if some properties of E are processed in the same way as the properties of one’s body”, is built from the multisensory integration of different channels of perceptive signals from both inside and outside the body. The final product of this elaboration creates a plausible and stable representation of our body. Thermosensory information coming from the skin may also play a role, and a growing body of evidence is trying to understand this complex interaction. In the current study, we temporarily modulated the sense of body ownership for the right and left hands of 36 healthy subjects, using Mirror-Box Illusion (MBI). During the task, consisting of a tapping movement performed in synchronous or asynchronous rhythm, we recorded brain activity through a 64-channel electroencephalography (EEG). Moreover, explicit judgments of body ownership were collected after the two experimental conditions, together with thermal imaging measurement. The expectation was to observe a stronger illusion during the synchronous condition, followed by a modulation of the sense of body ownership for the hidden hand. This effect can be found through a shift in the position perceived by the subject toward the covered hand, the proprioceptive drift, and a temperature decrease in both hands. Importantly, the current research aimed to find a connection between temperature modification and brain activity. Results obtained from behavioral and imaging analysis aligned with previous studies on the same topic. Preliminary EEG analysis, still ongoing, showed a temporal congruency between the synchronous tapping movement and the hand temperature modification. Moreover, the incongruency between motor and visual inputs perceived in the asynchronous condition would reflect on brain activity as a higher processing inter-trial incoherence, observed in a set of right frontoparietal areas. This evidence provides novel insight into the role of skin temperature in BSA and the underlying electrophysiological mechanisms. Keywords: body ownership, Mirror-Box, temperature, neural correlates