How Correct Rate Affected by Moving Speed of Stimulus in 'Imitating reading' Brain - Computer Interface

摘要

'Imitating reading' based brain - computer interface using visual evoked ERP paradigm to build a virtual keyboard. In this paradigm, the faster moving stimuli , the shorter the time required to select a button, but if the speed is too fast, the subjects may not clearly identify target stimuli, which will cause losing correct rate in button selection. In this paper, in order to find the best balance between the communication speed and correct rate, the recognition accuracy of seven subjects were observed by changing the stimulus moving speed below to each of the buttons (6ms/pixel, 5ms/pixel, 4ms/pixel, and 3ms/pixel, respectively). Experimental results show that stimulus in the moving speed of 6ms/pixel cause the lowest rate of correct identification, for most subjects , the highest accuracy appear at the stimulus moving speed is 4ms/pixel. The results have some reference value for the optimization of BCI.