Fig. 1: Schematic illustration of the experimental procedure.

A Overview of the experimental procedure. A total of 120 participants were randomly allocated to receive a single-session M1-rTMS, DLPFC-rTMS or sham stimulation. The rTMS stimulation was delivered by a figure-of-eight coil at the hand region of the left M1 for the M1 group, and at the F3 site of the International 10–20 EEG system for the DLPFC group. Before (T0), immediately after (T1), and 60 min after (T2) rTMS application, participants completed a pain-rating task that lasted about 12 min. During the task, a series of nociceptive laser stimuli were delivered to the dorsum of the right hand. Before the T0 session, laser stimulations in the task were calibrated individually to induce a painful but tolerable stimulation level (level 6). B Trial structure of the pain-rating task. Each trial began with a visual cue (a fixation) lasting 2 s, followed by a blank screen for 8 to 12 s. Then, a noxious laser stimulus was delivered to the hand dorsum. Followingly, participants were prompted to rate the pain intensity and unpleasantness evoked by the laser stimulation on a 0 to 10 numerical rating scale, with 0 indicating no pain/unpleasantness and 10 indicating unbearable pain/unpleasantness. Pain anticipation occurs between the presentation of a visual cue and the application of laser stimulation, while pain perception begins after the laser is delivered.