The design and implementation of visual braincomputer interfaces

As a new communication system that aims to replace normal output of the central nervous system, brain-computer interfaces (BCIs) has rapidly developed in past decades. However, the speed and reliability of current BCI systems remain far below that of conventional communication systems. Recently, visual BCIs have become popular because of the high communication speeds, ease of user training, and low user variation. But, building robust and practical BCI systems still poses a great challenge to researchers. This paper focuses on visual BCI systems, including BCIs based on brain responses to exogenous visual stimuli and endogenous potentials linked to the subject's reaction to the visual stimuli. The paper will review the existing visual BCI systems and explore the challenges in future development.