Does unihemispheric concurrent dual-site anodal transcranial direct current stimulation (a-tDCSUHCDS) of primary motor (M1) and dorsolateral prefrontal cortexes (DLPFC) affect motor skill learning in healthy individuals A randomized clinical trial

Background and Objective: Unihemispheric concurrent dual-site anodal transcranial direct current stimulation (a-tDCSUHCDS) of primary motor cortex (M1) and dorsolateral prefrontal cortex (DLPFC) has been introduced as an effective technique on M1 corticospinal excitability enhancement and its after-effects. The aim of the study was to investigate the potential effects of multiple sessions of a-tDCSUHCDS of M1-DLPFC on motor skill learning in healthy individuals. Materials and Methods: This study was a randomized clinical trial, a total of 37 volunteers completed all sessions of the study and were randomly divided into 2 groups, a-tDCSUHCDS and sham stimulation, by block randomization method. This study was performed from January to May 2017 in Iran. Participants took part in motor training task over 3 consecutive days for 20 minutes per daily session while they concurrently received a-tDCS at the same time each day. We assessed motor skills before the intervention (day 1), immediately after the intervention (day 3) and 1 week after the completion of the intervention.Findings: A total of 37 participants were included in the data analysis. Immediately after the completion of the intervention at day 3, results were as follows: mean skill in the experimental (0.33) and control (0.30) groups. 1 week after the completion of the intervention, results were as follows: mean skill in the experimental (0.36) and control (0.29) groups. The trend of motor learning considerably increased in the experimental (0.17; P < 0.001) and control (0.11; P < 0.001) groups. No significant difference was found in motor learning immediately after the intervention between the groups (P = 0.23), while there was a significant difference in long-term offline learning between the groups (P = 0.04).Conclusion: The persistence of greater motor skills in the a-tDCSUHCDS group compared to the sham tDCS group at 1week retention indicates the robustness of the a-tDCSUHCDS effect.

کلیدواژه ها:

Transcranial Direct Current Stimulation ، Motor Cortex ، Prefrontal Cortex ، Motor Skills ، Learning