Evaluation of an eye gaze point detection method using VEP elicited by multi-pseudorandom stimulation for brain computer interface

A method for detecting eye gaze point using visual evoked potentials (VEPs) elicited by pseudorandom stimuli was examined. Prototype system which would be a practical brain computer interface is established and evaluated. Four luminance modulated red characters based on four different pseudorandom binary sequences (PRBS) of 5.11 seconds were simultaneously presented on a monitor, and the cross correlation functions (kernels) of VEPs and each PRBS were calculated and used to determine the subject's gazed target. In an experiment with subjects with normal vision, their gazed target was obtained from VEPs within 7 seconds, and the mean error rate of detection was 22%. Results indicated that this technique could be useful as a practical brain computer interface system.