Cone contrast influence on components of the pattern onset/offset VECP

摘要: Transient visual evoked cortical potentials (VECP) were recorded from the scalp of healthy normal trichromats (n = 12). VECPs elicited by onset/offset presentation patterned stimuli two kinds: isochromatic luminance-modulated, and equiluminant red-green modulated, sine wave gratings. The amplitude latency major onset components VECP measured plotted as a function logarithm pooled cone contrast. early components, achromatic C1 chromatic N1, increase linearly with log contrast, but N1 has higher contrast gain than C1. late C2 N2, have similar gain, response level: both in low-to-medium range contrasts saturate at high levels. In tested, show latencies, whilst shows shorter latencies N2. We suggest that are generated same mechanism low luminance N2 different mechanisms.