Effects of transcranial alternating current stimulation on performance of SSVEP-based brain-computer interface

It is known that steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) has a high information transfer rate compared with other BCI paradigms in general. However, some subjects may have low response to visual stimulation, and the performance of SSVEP-based BCI may be poor. Previous study has found that transcarnial alternating current stimulation (tACS) can modulate brain cortical excitability and ongoing oscillatory activity, so it may help to improve the neural response of visual cortex. We are inspired to investigate the influence of tACS on improving the performance of SSVEP-based BCI. We conduct the experiment on six healthy subjects in two groups, tACS group and sham (no tACS) group. The classification accuracy of BCI is improved significantly after treatment in tACS group, while there is no obvious change in sham group. It indicates that tACS is not a placebo, and it can improve the classification accuracy of SSVEP-based BCI. We also find the positive effect is not restricted to a particular visual stimulation frequency in SSVEP.