Globality and stereoscopic fusion in binocular vision

The precedence of binocular fusion over binocular rivalry

“…For a time, some visual scientists believed that binocular rivalry was the onlyprocess involved in binocular single vision, with apparent fusion resulting from rivalry ongoing inconspicuously (e.g., Asher, 1953). This strict suppression theory is now largely rejected in favor of models that incorporate both fusion and suppression processes (e.g., Nelson, 1975). According to these models, fusion and rivalry can coexist within different parts of the visual field: objects situated on or near the horopter produce compatible monocular images that are seen as single, whereas objects located well off the horopThis work was supported by a grant from the National Science Foundation (BNS82-OO850).…”

Three-dimensional displays and stereo vision

“…The random-dot pattern is the same in the two eyes, except for a patch in the middle, which is displaced laterally in one eye by the width of one dot with respect to the other. On the right is shown diagrammatically the disposition of the dots in a single row, showing how the visual system is required to establish matches, favouring some over others in the interest of global coherence that then makes the central patch appears behind the remainder of the panel [13]. from the display is passed through a screen with suitably synchronized changing angles of circular polarization.…”

“…In figure 4 [13], two rows are shown, one just above the disparity patch, one just within it. A dot in one eye should be matched with just one in the other, leaving in the end only two levels of disparity.…”

The dependence of cyclofusion on orientation

“…He found that when each eye is presented simultaneously with contours rotated by small but opposite amounts from vertical, a single contour is seen. This single contour has an orientation that is between those of the two monocular displays (allelotropia, Nelson, 1975) and is, moreover, seen as tilted in depth (see Figure la). There is some debate as to the manner in which such binocular cyclofusion occurs.…”

“…The impression of depth must then arise from some other mechanism (e.g., afference from the extraocular muscles mediating the cyclovergence). Others (e.g., Kertesz, 1971Kertesz, , 1972Kertesz, , 1973aKertesz, , 1973bNelson, 1975) assert that binocular fusion is neural in nature. Specifically, Barlow, Blakemore, and Pettigrew (1967) argue that although retinal areas may be geometrically noncorresponding, they are neurally corresponding in that the areas form the separate monocular receptive fields of the same binocular cortical neurons.…”