Safety and Acute Effects of tDCS on Vocal Performance in Adolescent Singers

概要

This randomized, sham-controlled proof-of-concept study aims to investigate the safety, tolerability, and acute effects of transcranial direct current stimulation (tDCS) on vocal performance in adolescent singers aged 12 to 16 years. Twenty-four participants will be randomly assigned in a 1:1 ratio to active or sham tDCS. Active stimulation will consist of 2.0 mA anodal tDCS applied for 20 minutes using 5 × 7 cm electrodes, with the anode positioned over C5 to target the left laryngeal primary motor cortex and the cathode over the right supraorbital region. Participants will perform the same standardized vocal piece before stimulation, immediately after stimulation, and approximately two hours after stimulation. Vocal performances will be audiovisually recorded and evaluated by blinded expert raters using an adapted analytical vocal-performance rubric based on Gynnild (2015). Safety and tolerability will be monitored using a structured symptom checklist and predefined stopping criteria. Self-rated vocal performance, nervousness, confidence, blinding, and protocol feasibility will also be explored.