A Hybrid BCI Paradigm Based On P300and SSVEP

Many disabled patients have a lot of trouble in their daily life. They can not walk since the leg injury, can not grab things since the hand injury or even can not live without other’s help since the paralyzed body. Some of them can not communicate with the other people and outside environment normally, however, their brain’s function is not injured. Because of this finding, a new technology called the brain-computer interface (BCI) was presented, which was based on the brain signal.The BCI is a communication system that allows users to send messages and commands to a computer or other external device through direct measures of brain activity. Currently, P300and steady-state visual evoked potential (SSVEP) approaches have been widely used for brain-computer interface (BCI) systems. However, neither of these approaches can work for all subjects. Recently, some groups have reported that a hybrid BCI that combines two or more approaches could enlarge the user group of BCI.The main task of this project is the design and optimization of the hybrid BCI paradigm. This paper presents a new hybrid paradigm which can evoke P300and SSVEP simultaneously. In this paradigm, P300is evoked by shape changing, and the SSVEP is evoked by frequency flickering. The performance of the new hybrid paradigm is compared to the traditional P300, SSVEP, and hybrid paradigms based on the result of the offline experiment. The result shows that the new hybrid paradigm yields much better performance than the traditional hybrid paradigm, and slightly better than the traditional P300and SSVEP paradigms.