High-Definition Transcranial Direct Current Stimulation (HD-tDCS) enhances working memory training

High-Definition transcranial direct current stimulation (HD-tDCS) is a noninvasive brain stimulation technique that can improve the performance of working memory (WM). However, the current researches have focused on the effects of stimulation, while ignored the process of stimulus and the neural mechanism. The targets of this study were to explore the effects of different stimulus categories (active or sham) applied on left dorsolateral prefrontal cortex (LDLPFC) on WM training, as well as the physiological changes in the brain after training. Behavioral and electroencephalography (EEG) results of 20 participants showed that HD-tDCS significantly enhanced training effects in the later training period. Furthermore, WM ability benefited from training combined with HD-tDCS, and active group found the time-dependent desynchronization (ERD) weakened in α and β band, while sham group increased. The results supported the viewpoint that HD-tDCS can shorten the training time and alter neurons rhythm, it may be used as psychotherapy for the patients with brain injury.