Extraction of the Opponent Colours Responses from Visual Evoked Potentials Elicited by Multi-Colour Stimulation

Visual evoked potentials to the simultaneous presentation of two colours (multi-colour stimulation) were investigated to measure the characteristics of human colour vision. Multi-colour stimulation which consists of two iso-luminant colour stimuli presented with a pseudorandom binary sequence (PRBS) were employed to elicit VEPs, and the first-order binary kernel of the VEPs was calculated using multi-input system analysis technique. The waveforms of the kernels elicited by the two colour presentations were similar to those obtained by one colour stimulation, indicating that the multicolour stimulation can reduce the measurement time. In addition, the opponent colours responses were obtained from the first-order kernels for eight colours by applying the principal component analysis. These indicated that the VEP measurement with multi-colour and pseudorandom stimulation would be a practical and rapid method of testing the human colour vision objectively.