An online gaze-independent BCI system used dummy face with eyes only region as stimulus

Abstract

The gaze-independent brain-computer interface (BCI) based on rapid serial visual presentation (RSVP) is an extension of the oddball paradigm, and can facilitate communication for people with severe neuromuscular disorders. Some studies suggested that a face with eyes only (without other facial features) could evoke ERPs as high as a complete face. To evaluate the performance of a BCI system, an online system is needed. In this paper, we compared two types of stimuli: a dummy face with eyes only and a colored circle. Ten healthy subjects (8 male, aged 24–28 years, mean 26 ± 1.5) participated in our experiment. The results showed that the dummy face with eyes only had substantial advantages in online classification accuracy (t = 2.3, p = 0.04) and information transfer rate (t = 3.4, p = 0.003). Results from users’ feedback also showed that the dummy face with eyes only stimulus was more easily accepted (t = 4.12, p< 0.001).