Detecting the displacements of spatial beats: a monocular capability.

Sensitivity to the sudden displacement (phase shift) of a single monocularly presented sinusoidal grating is increased when a static grating of similar spatial frequency is presented to the same eye. If the static grating is presented to the other eye instead sensitivity is, at best, halved. This demonstration implies that monocular and binocular visual pathways differ in their sensitivity to spatial variations of contrast. In addition it provides another example in which the monocular visual pathways are more sensitive to spatial displacements than the binocular pathways.