Amplitudes of visually evoked cortical responses due to full-field stimulation and to stimulation with four half-fields.

In 30 healthy subjects the VECP following full-fields, upper, lower, nasal and temporal half-field stimulation was recorded. The full-field amplitudes is significantly larger than each of the half-field responses. For peak P120, the amplitudes following lower half-field stimulation is significantly larger than the amplitude due to upper, nasal and temporal half-field stimulation. The sum two half-field amplitude is significantly larger than the full-field response.