Transcranial Direct-Current Stimulation Effect on a Speech-Imagery-based BCI

Transcranial direct current stimulation (tDCS) is a neuromodulation technique that applies a small electrical current to a user's scalp to stimulate the brain. This preliminary study is conducted to examine the effect of tDCS to the performance of a speech-imagery-based brain-computer interface (SI-based BCI) system. SI-based BCI experiments were conducted on six participants where three participants receive tDCS and the other three receive sham-stimulation. The comparison between the accuracy of pre-stimulation and post-stimulation sessions of tDCS and sham-stimulation group suggests that a tDCS can slightly boosts the performance of a SI-based BCI system. However, the experiment is needed to be repeated on a greater number of participants to confirm the theory.