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.