Effects of Multisession Transcranial Direct Current Stimulation on Arithmetic Performance

We evaluated the effects of transcranial direct current stimulation (tDCS) on cognitive performances including the arithmetic performance, working memory, and electroencephalography (EEG) measurements of healthy participants when applied over multiple sessions spanning a five-day period. In a double-blind crossover randomized controlled study, participants received either active left tDCS or sham stimulation. Despite no significant changes in arithmetic performance, the tDCS group displayed enhanced reaction time and accuracy in a 2-back task compared with the control (sham) group, and EEG measurements revealed an increase in the alpha-band power spectral density (PSD) at the left temporal lobe for the treatment group over the experimental period, suggesting modulations in cortical activity. Further research is needed to elucidate the specific cognitive regions affected by tDCS and the underlying neurophysiological mechanisms.