Visual evoked potentials elicited by circular grating.

In the belief that it would prove a more effective stimulus for eliciting visual evoked potentials, a circular grating was designed so that the relationship between its bar width and visual acuity was held constant, and, therefore, the bars were equally well resolved across the visual field. Visual evoked potentials elicited by the onset presentation of the pattern were evaluated but found to be excessively variable owing to summation of different waveforms generated by equivalent stimulation of different parts of the visual field.