Transcranial Direct-Current Stimulation Can Enhance Motor Learning in Children

Abstract

This study aims to determine the effects of transcranial direct-current stimulation (tDCS) on motor learning in healthy schoolaged children. Safety, tolerability, and translation of effects to untrained taskswere also explored.We recruited 24 right-handed children for a randomized, sham-controlled, double-blinded trial to receive: right primary motor cortex (M1) 1 mA anodal (1A-tDCS), left M1 1 mA cathodal (1C-tDCS), left M1 2 mA cathodal tDCS (2C-tDCS), or sham tDCS over 3 consecutive days of motor task practice. Participants trained their left hand to perform the Purdue Pegboard Test (PPT) during tDCS application. Right hand and bimanual PPT, the Jebsen-Taylor Test (JTT), and the Serial Reaction Time Task (SRTT)were tested at baseline and post-training. All measures were retested 6 weeks later. Active tDCS montages enhanced motor learning compared with sham (all P < 0.002). Effectswere sustained at 6 weeks. Effect sizeswere large and comparable across montages: contralateral 1A-tDCS (Cohen's d = 2.58) and ipsilateral 1C-tDCS (3.44) and 2C-tDCS (2.76). Performance in the untrained hand PPT, bilateral JTT, and SRTT often improved with tDCS. tDCSwaswell-tolerated and safe with no adverse events. These first principles will advance the pairing of tDCS with therapy to enhance rehabilitation for disabled children such as those with cerebral palsy.