Researching Hemispheric Specialization in the Control of Final Position Accuracy Using the Transcranial Direct Current Stimulation

Abstract

Transcranial Direct Current Simulation (tDCS) can improve or disrupt brain functions and can therefore be used to investigate hemispheric specialization. Accordingly, this study was designed to research hemispheric specialization in the control of final position accuracy by comparing the effects of tDCS on dorsolateral prefrontal cortex (DLPFC) in the right and left hemispheres. Forty-three right-handed male university students(aged 21.34±1.61) volunteered to participate in this study. They were divided into the right DLPFC, left DLPFC, sham, and practice groups, including 12, 11, 9, and 11 participants, respectively. After learning motor skills in two days, the participants practiced final position accuracy in one day. They were asked to move the cursor toward the centers of targets appearing randomly at the top, middle, and bottom on the right side of a monitor as accurately and quickly as they could. At the time of practice, the participants received anodic stimulation in one hemisphere and cathodic stimulation in the other. The results indicated that the left anodic/right cathodic group (left DLPFC) showed the worst performance, which may be caused by the inhibitory effects of cathodic stimulations in the right DLPFC. Therefore, it is predicted that the right hemisphere may have greater specialization in final position accuracy of movement.