ORIENTATION EFFECT OF VISUAL EVOKED POTENTIAL FOR DIFFERENT STIMULUS LOCATIONS ON THE HUMAN RETINA
视觉诱发电位(VEP)方位效应与刺激位置的关系

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. At eccentricities of 20 degree, VEP yielded the largest responses to gratings perpendicular to the visual field meridians through stimulus locus and the lowest responses to meridionally oriented gratings. No obvious relation between VEP amplitude and grating orientation found implies that VEP ampltude was only relative to deviating angle (i. e. the angle between the optimum orientation and visual field meridian) in peripheral vision. For central vision, VEP response to the same grating was independent of orientation.