Central visual field contributions to the visual-evoked response.
Visual evoked responses (VER) were recorded from bipolar electrodes placed transversely across the occipital region. A series of apertures were used to block the stimulation of the foveal area. The transverse distribution of the C2 component of the VER corresponds to a radial dipole source, and this is consistent with a foveal origin in the visual cortex. A clinical test for the presence of intact foveal projection, when opaque media preclude more conventional tests, could employ the VER.
D003201:Computers; D005071:Evoked Potentials; D005584:Fovea Centralis / Q000502:physiology*; D006801:Humans; D008266:Macula Lutea / Q000502:physiology*; D010775:Photic Stimulation; D010827:Physiology / Q000295:instrumentation / Q000379:methods; D012607:Scotoma / Q000503:physiopathology; D014793:Visual Cortex / Q000502:physiology; D014794:Visual Fields