Effort and Issues in Development of High-Frequency Stimulus SSVEP-BCI for Flicker Stress Reduction

Abstract

Steady-state visual evoked potential (SSVEP)-brain-computer interface (BCI) has fast input speeds, high accuracy, and a large number of inputs. The problem with SSVEP is the stress caused by flickering stimuli and the risk of developing photosensitivity. In this study, we attempted to reduce flicker stress by developing a high-frequency SSVEP-BCI. In addition, we measured the critical fusion frequency (CFF) at which humans cannot perceive flicker and investigated the change in BCI performance below and beyond CFF to examine the practicality of the high-frequency SSVEP-BCI. The results showed CFF was 56.8 Hz. Also, an accuracy of 58.75% for high-frequency (56-70 Hz) SSVEP-BCI and 90.5% for low-frequency (26-40 Hz) SSVEP-BCI. For this reason, the high-frequency SSVEP-BCI could not obtain the same performance as the low-frequency SSVEP-BCI. Therefore, it is necessary to consider the use of extremely low-frequency stimulation and improve the analysis algorithm in the future.