Visual evoked potentials (VEPs) in response to pattern-reversal stimulation are generally recorded under photopic conditions. We have studied the VEPs in 22 healthy volunteers at stimulus intensities of between 4 x 10-2 and 40 cd/m2 of stimulus intensities. The scotopic pattern-reversal VEPs (sPVEPs) showed a primary positive component between 200 and 300 ms, depending on the stimulus intensity. The amplitude of the positive component was only slightly smaller than that of the photopic pattern-reversal VEP (pPVBP). Dark adaptation induced a significant, albeit small-increase in the amplitude of the primary positive component. Significant differences were seen between the scalp distributions of the potential fields of VEPs recorded under scotopic and photopic conditions. The topographical differences may be caused by the foveal vs extrafoveal contribution of the pPVEPs and sPVEPs, respectively. Recording sPVEPs may offer a useful method for investigation of the physiological and clinical problems related to scotopic/peripheral vision.
|Number of pages||8|
|Journal||Clinical Vision Sciences|
|Publication status||Published - Jan 1 1993|
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