Multifocal visual evoked potential responses to pattern-reversal, pattern-onset, pattern-offset, and sparse pulse stimuli

Abstract

The purpose of the present study was to compare standard multifocal visual evoked potential (mfVEP) pattern-reversal responses with those produced by pattern-onset, pattern-offset, and pulsed pattern stimuli. mfVEP recordings were obtained from five normal subjects using VERIS and a 4-electrode array. The standard reversal stimulus had 215 m-sequence steps (7.5-min duration). Pattern-onset and -offset responses were evaluated using sequences that all had 32 frames per m-step and 210 total steps (7.5 min); but the duration of the contrast step varied so that it was 1, 2, 4, 8, 12, or 16 of the 32 frames. The same series was also inverted so that adapting contrast was high and the stimulus ste..