“…31 The discrepancy between our results on binocular summation at suprathreshold and those reported by Collier 11 and Campbell & Green 13 at the threshold, can be explained by assuming that, at the threshold, these mechanisms present no significant activity, as might occur under suprathreshold conditions. It noteworthy that Dinse and Krüger 49 found in peristriate cortical regions, where eye control is processed, [4][5][6]41 signal-to-noise thresholds higher than near and striate areas. Similarly, in pupillogram studies, when stimuli were just above the threshold, pupil reflexes were weaker, the speed of response was slower, and latency increased in comparison to responses for clearly visible stimuli.…”