Interactive Brain-Computer System for Assessing Binocular Rivalry and Amblyopia Based on VR

Binocular rivalry (BR) is the competition of two eyes when shown with different patterns, which is regarded as a neurological symptom. Since the interocular suppression of BR is related to amblyopia and affects the development of visual function, it is essential to assess both BR and amblyopia. Conventional methods assessing the severity of neurological symptoms rely on chromatic aberration glasses or stereoscope to display BR patterns and stereoscopic objects. However, glasses and stereoscopes are hard to perform respectively and dynamically with 2D displays. In this paper, we adopt virtual reality (VR) as a proper display and interaction media for separated screens and dynamic stereoscopic vision to develop a BR assessing system. To promote the usability of interocular suppression measurement, we further apply steady-state visual-evoked potential (SSVEP) stimulus in VR head-mounted display (HMD) and integrate the stimuli into virtual environments due to the high information transfer rate and accessibility among brain-computer interface (BCI) of SSVEP. Sixteen (16) subjects took part in the experiment, through which the proposed system is effective for BR measurement and amblyopia rehabilitation and outperforms the conventional methods. The proposed method enjoys the benefit of personalized measurement for BR severity and the degree of amblyopia subjectively.