A high performance SSVEP-BCI without gazing

Brain-computer interfaces based on steady-state visual evoked potential (SSVEP-BCIs) achieve a high performance due to their multiclass nature in paradigms where gazing is needed. Studies of binary SSVEP-BCIs have been presented without the need of gazing at the expense of low performance. This study presents a high performance binary SSVEP-BCI that allows an efficient communication without the need of gazing. The information transmission rate (ITR) obtained was 0.64±0.27 bits per seconds with peaks of 1.16 bits per second and an accuracy of 90±7%, which is an excellent performance for a binary SSVEP-BCI. To achieve this performance two main factors were involved: on the one hand, the use of both amplitude and phase of the SSVEP in the classification and, on the other, the use of the absence of gaze (“thousand-yard stare”) as a way of helping to ignore the stimulus.