16 ats thermode

Experimenters used a 16 × 16 ATS thermode (Medoc Ltd, Ramat Yisha, Israel) to apply different levels of thermal stimulation at participants’ inner volar left (non-dominant) forearms. Before each heat trial, experimenters attached the thermode via Velcro. To measure heat-evoked SCRs, we used the Biopac MP150 EDA-100C module (Biopac Systems, Inc., Goleta, CA, USA), attaching two shielded silver-silver chloride electrodes at participants’ hypothenar muscles of the non-dominant hand. Following Biopac’s recommendations, the experimenters applied NaCl electrolyte gel (GEL101) to enhance electrode conductivity. We continuously collected skin conductance at a sampling rate of 2000 Hz. When measuring heat-evoked pain and autonomic responses, we used Experiment Builder software (SR Research Ltd., Ottawa, Ontario, Canada) to show instructions to participants and to collect self-reported pain responses.

Participants received different levels of thermal heat stimulation on eight sites of the non-dominant inner volar forearm via a 16 × 16 ATS thermode (Medoc Ltd., Ramat Yisha, Israel). During both pain assessment tasks, we recorded skin conductance using the Biopac MP150 EDA-100C module (Biopac Systems, Inc., Goleta, CA, USA) via two shielded silver-silver chloride electrodes. We prepared electrodes with NaCl electrolyte gel (GEL101) as recommended by Biopac Systems for skin conductance measurement. We attached electrodes at the hypothenar muscles of participants’ non-dominant hands. During the ASC, we also recorded pupillometry data from the participant’s right eye using the Eyelink 1000 Plus eye tracking system (SR Research Ldt., Ottawa, Ontario, Canada). We used a 9-point calibration and validation procedure to calibrate gaze position and pupil measurement. Visual stimuli (e.g. fixations) and behavioral responses (e.g. pain ratings) were presented and collected using Experiment Builder software (SR Research) for ASC and E-Prime 2.0 software (Psychology Software Tools, Pittsburgh, PA) for TSPA.