TaVNS Application Timing During Robotic Sensorimotor Task

taVNS in this study involves short electric pulses (0.25 ms) delivered to the ear's skin to activate the auricular branch of the Vagus. The pulses are current-controlled to ensure stability and delivered in a bipolar fashion to prevent skin irritation. Before each session, taVNS is calibrated for each participant. Starting at 0.1 mA, the intensity is increased stepwise until a comfortable maximum (typically 1.5-2.5 mA) is reached. Stimuli are delivered in short trains lasting 0.5 seconds each, with 13 pulses (0.25ms each) per train. Participants receive a maximum of 150 stimuli per session, totaling a maximum of 75 seconds of cumulative stimulation. Participants adapt their movements over up to six sessions across two weeks. The robotic task facilitates accurate movement tracking and provides interactive real-time feedback.