White noise effects on pattern-reversal visual evoked potentials.

Visual evoked potentials (VEPs) were recorded in 9 subjects from occipital and temporal leads. The stimulus was a checkerboard phase-reversed at the frequency of 1 Hz, binocularly viewed by the subject. VEPs were recorded during white noise stimulation (9 different levels of intensity) and without noise stimulation. P100 latency was not affected by the white noise stimulation, whereas the N75-P100 amplitude turned out to be affected by the simultaneous auditory stimulation with different patterns in relation to the site of the recording. The results are discussed in terms of general activation aroused by the white noise on visual information processing.