[The dependence of the cortical topography of visual evoked potentials on the stimulation frequency]

Cortical topography of steady-state flash visual evoked potentials (fVEP) was compared with topography of transient fVEP and pattern VEP (pVEP) in 17 normal subjects. It was found that at low (up to 20 Hz) frequencies fVEP demonstrate extensive dissemination on the scalp. At higher frequencies (30 Hz or higher) fVEP were registered mostly in the occipital area similarly as transient pVEP. These results suggest that the neural structures responsible for the generation of transient pVEP and steady-state fVEP of 30 Hz and higher frequencies are anatomically identical.