Visual fatigue effects on Steady State Visual Evoked Potential-based Brain Computer Interfaces

Brain computer interfaces are a direct communication pathway between the brain and external devices and require mental effort to work efficiently. After long use of such interfacing systems, subjects have reported fatigue symptoms. Fatigue influence on the EEG signals could disrupt human-computer communication and decrease the reliability of the responses. In this paper, fatigue effects on SSVEP-based BCI use are evaluated. Thirteen healthy subjects participated in the experiment, which uses a BCI system originally designed for online wheelchair navigation. Signal analysis was based on accuracy rates, band power spectra and SSVEP amplitudes extraction. Although accuracy levels show no statistically significant differences, self-reported fatigue levels increase and SSVEP amplitudes decrease with time. Our analysis demonstrates no consistent band power changes.