Effects of a Single Session Transcranial Direct Current Stimulation (tDCS) on Hand Mental Rotation and Visuo--Spatial Working Memory

The purpose of this study was to investigate the effects of one session of transcranial direct current stimulation (tDCS) on hand mental rotation (HMR) and visuo-spatial working memory (VSWM). The 54 right handed students of sport science at University of Tehran were selected and then were randomly divided into two groups of anodal (N=27) and sham (N=27), and further were divided in two subgroups according to site of stimulation (F4 & P4) (total of four groups). Before and after the application of tDCS, participants completed the HMR Task and Corsi test (to study VSWM). Results of anodal group showed a significant difference between the pre-test and post-test in reaction time and accuracy of HMR, also reaction time and span of Corsi in both sites (F4 & P4) . Also, comparing the effects between two sites in HMR, revealed that subjects responded faster and more accurately in F4 than P4. But only in foreward Corsi test, response time was faster in F4than P4. According to the findings of the present study, both F4 and P4 sites could be used to improve motor imagery and visual-spatial memory while the F4 showed better result.