Visual evoked potentials to various check patterns.

A target screen stimulus takes into account the necessity of larger checkerboard patterns with rising eccentricity. The target pattern should be calculated to fit the retinocortical magnification factor. This proposition is based on the working hypothesis that for maximal visual evoked potential (VEP) amplitude the stimulus should appear on the cortex as an undistorted checkerboard pattern. We describe the cortical response elicited by four different target screen stimuli based on a similar algorithm. No significant difference to normal checkerboard was found.