Binocular interactions in visual evoked cortical potentials with two light-emitting-diodes

Binocular interaction for a central field was studied with transient scalp visual evoked cortical potentials (VECPs) using two light-emitting-diodes. VECPs were obtained for binocular and monocular visions with dominant and n on-dominant eyes, and arithmetical sums of monocular VECPs with dominant an d non-dominant eyes were calculated. Amplitude and latency of remarkable in itial three peaks were tested with the multivariate analysis of variance. S ignificant differences were noted among the four VECPs. Pairwise comparison s showed that (1) the amplitude of the first peak for the binocular VECPs w as larger than that for the monocular VECPs but smaller than that for the s um-VECPs; the latency of the first peaks for the binocular VECPs were earli er than that for the monocular VECPs with the non-dominant eye; (2) the amp litude of the first negative peak for the sum-VECPs was larger than that fo r the binocular VECPs, and the peak latency for the sum-VECPs showed later than that for the binocular VECPs; (3) the amplitude of the second positive peak for the binocular VECPs and monocular VECPs with the dominant eye was larger than that with the non-dominant eye, but smaller for the binocular VECPS than that for the sum-VECPs; the latency for the binocular VECPs show ed earlier than that for the monocular VECPs with the dominant eye and for the sum-VECPs. Binocular suppression was noted in amplitude for the three p eaks and binocular facilitation was noted in latency for the latter two