Properties of the flash visual evoked potential recorded in the cat primary visual cortex

The flash visual evoked potential (F-VEP), elicited by a 100 ms diffuse light flash presented at 2 Hz, was examined in the cat primary visual cortex (Area 17). Intracortical F-VEP depth profiles were recorded to characterize waveform changes with electrode depth. A positive surface component, with a latency of 200 ms, was the dominant waveform feature within the cortex, reversing in polarity and increasing in magnitude as the cortex was penetrated. Other prominent components with latencies of 30, 50, 100, and 125 ms were also observed. Changes in the waveform with stimulus duration and illumination were examined and revealed the sensitivity of prominent components to stimulus parameters.