Abstract
A dichoptic stimulation paradigm was used to determine the degree to which the two monocular images must match in terms of the temporal properties to yield facilitation in binocular grating detection. Several converging lines of evidence point to the existence of two separate neural mechanisms in binocular detection. One of these mechanisms is selective for temporal frequency and limited in its capacity to integrate information from the two eyes over time. The other mechanism is much less selective for temporal frequency and integrates over a longer period of time. At threshold these two separate mechanisms behave independently and exhibit similar degrees of binocular summation.