Pattern-evoked potential latencies from central and peripheral visual fields.

Abstract

Median P100 and N70 latencies for peripheral field (>8 degrees) TV-generated pattern visual-evoked potentials were 6 and 8 milliseconds less than for central field patterns in subjects with normal pattern visual-evoked potentials. These differences held for patient subgroups with P100 latency maxima from 140 to 100 milliseconds, and for left and right eye data separately compiled. Latencies for central field stimulation exceeded those for peripheral field stimulation in 233 (85%) of 274 eyes for the N70 potential and in 210 (77%) of 274 eyes for the P100 potential. Such data suggest that the faster conducting peripheral visual system, conveying location and motion information, prepares the occipital cortex for the later arriving central data conveying more intricate details.