Visual evoked potentials (VEP) to square-wave gratings (spatial frequency 1.4 c/deg. , flickering frequency 2.9 Hz, contrast 0.94) at various stimulus locations on the retina were recorded from human occipital scalp.

• 以人视觉诱发电位(VEP)反应为指标；在视野的不同位置测定了VEP对四个方位的闪烁方波光栅刺激(时间频率2.；9Hz；空间频率1