EEG data MiEEG data Mirror Visual Feedback with electrical painful and non-painful stimulationsrror Visual Feedback with electrical painful and non-painful stimulations

Experimental procedure:The participants were comfortably seated on a chair with their arms lying symmetrically ahead on a table. Auditory cues of 70 dB, 1000 Hz, and 50 ms of duration (Kida et al., 2006) were used to trigger right index finger movements. All the subjects underwent three different conditions (80 trials each) in randomized order. Each condition lasted approx. 13 min with 10 min breaks between the conditions. The whole session – including EEG net preparation, training, pain threshold measurement, and experiment – lasted approx. 2.5 hours. In the experimental condition (Unilateral with Mirror, or UM+), the mirror was placed on the desk, perpendicularly to the subjects’ midsagittal plane with the reflecting face on the right side (Figure 1). Subjects were instructed to move the right index finger in response to the auditory cue while watching the image of the reflected moving hand in the mirror to give the illusion of the simultaneous left index finger movement. The position of the left hand behind the mirror corresponded to the image of the left hand reflected in the mirror. In the control conditions, the mirror was removed from the experimental setting and the left hand was directly visible to the participants. In one control condition (Unilateral without Mirror, UM-), subjects were asked to perform the same unilateral right index finger movements. In the other control condition (Bilateral without Mirror, BM-), subjects had to perform synchronous movements of both index fingers. The movements consisted of a double extension of the index finger with a slow release toward the bottom (approx. 1 s). All the participants received a brief training to perform the movement correctly and keep the left hand as still as possible during the unilateral conditions. In each condition, an electrical stimulus was delivered on the tip of the left index finger 100 ms after the auditory cue to induce cortical sensory-motor interaction (Figure 2). The interval between the stimuli was fixed at 10 s, a sufficient period to reset the desynchronization of the alpha rhythms (Babiloni et al., 2008). A fixed interval also allowed to produce a sort of predictability of the upcoming auditory and electrical stimuli, optimal to study the anticipatory alpha ERD/ERS responses. However, subjects were not informed of this fixed interval to avoid any counting strategies.EEG data are uploaded in .hdf5 extension (g.recorder amplifier) to be analyzed with EEGLAB toolbox for MATLAB.Raw data coding slightly differs from the one presented in the original manuscript:no-M+P = UM-no-M+P-bil = BM-yes-M+P = UM+