Body Ownership and Skin Temperature: an EEG Exploration Using the Mirror Box Illusion

An important component of bodily self-awareness is body ownership, which is the awareness that one's body, or a part of it, belongs to oneself (Crivelli et al., 2021). Temporary disruption of this process can cause physiological changes, such as changes in skin temperature. Although previous studies have demonstrated that body ownership illusions can reduce skin temperature, the neural mechanisms underlying this relationship in healthy individuals remain unknown. (Crivelli, Polimeni, et al., 2021; Moseley et al., 2008; Salomon et al., 2013). The thesis addresses this gap by investigating the electroencephalographic (EEG) correlates linked to changes in skin temperature and body ownership using a modified mirror-box illusion (MBI) paradigm. Thirty-six healthy, right-handed participants performed synchronous and asynchronous finger-tapping tasks. Thermal imaging was used to measure the skin temperatures of both hands before and after each experimental condition. At the same time, 64-channel EEG recordings were being performed. Results showed that synchronous stimulation caused a significant bilateral decrease in hand temperature compared to asynchronous stimulation (p < .001), along with increased proprioceptive drift and ownership (p < .001). EEG analyses identified a right premotor/SMA cluster with significant differences in theta (4–7 Hz) and alpha (8–12 Hz) oscillations between conditions at 300 – 600 ms. These results suggest asynchronous stimulation demands greater cognitive effort to resolve sensory conflict, indicated by increased spectral perturbation and reduced inter-trial coherence. Moreover, a significant negative correlation between alpha power in the right frontal cluster and skin temperature decrease linked neural activity to thermoregulatory changes.