Anisotropies in the perception of stereoscopic surfaces: The role of orientation disparity

Abstract

We measured stereoscopic slant detection thresholds for surfaces slanting about a horizuntai or a vertical axis. For randomdot covered s&aces, 1.25deg uf slant was required to detect slant about a ants axis, whereas 2.1 deg of slant was required tu detect sbmt abut 8 wrtic8l mds. T&3 8nisOtrOpy could be due t0 the fact th8t Orieltt8tiOO 4#k!iptitiwt Which ~311tim kki~8tiOn about mrf8ce slant, are generally smaller for surfaces slsnting about 8 verticad 8xis. To test this possibility, slant threshuids were measured for surfaces whose orientation disparity content was manipulated ~~~~tly of the other slant i~o~~n present. When tlie magm&ude of orientatiun disparity was thesame fOr ~8~~aUti~~~ta ho~zo~81~ 8 VerticaI 8X~~~~~~O~~~~~~~ about 1.5 deg of slant to be detected; thus the anisutropy became negiigiile. In contrast, when the o~en~tion disparity content of 8 surface slanting about a vertical axis was zeru, 3-4 deg of sknt was required fur detection; thus the anisutrupy became larger. Under the conditiuns of these experiments, it appears that the visuai system utilizes o~e~tation disparities.

Orientation Disparity: A Cue for 3D Orientation?

“…However, these data have never been published in a peer-reviewed journal, and to our knowledge, the effect has not been replicated. Psychophysical studies of orientation disparity have had conflicting interpretations (Gillam & Rogers, 1991;Gillam & Ryan, 1992;Cagenello & Rogers, 1993;Heeley, Scott-Brown, Reid, & Maitland, 2003). In general, these studies have found evidence that humans can perceive slant from binocular images related by geometric distortions that are consistent with orientation disparity and that sensitivity to slanted surfaces depends on the orientations of the texture elements.…”

Receptive Field Size in V1 Neurons Limits Acuity for Perceiving Disparity Modulation

“…10). Although it has been suggested that such orientation differences might be a specialization for detecting surface slant (Blakemore et al, 1972;von der Heydt, 1978;Ninio, 1985;Mitchison and McKee, 1990;Cagenello and Rogers, 1993), within the context of the energy model, the response remains dominated by the effects of positional disparity , their Fig. 7), so that the modulation at low frequencies is very similar to that at intermediate frequencies.…”

Perceptual latencies to discriminate surface orientation in stereopsis

“…The perception of inclination was faster. This difference in performance between the two orientations is one aspect of the so called stereoscopic anisotropy, which is also manifest in terms of differences in threshold performance and differences in the magnitude of perceived depth, despite the fact that the magnitudes of the positional disparities are the same in each case (e.g., Bradshaw & Rogers, 1999;Cagenello & Rogers, 1993;Gillam & Rogers, 1991;Mitchison & McKee, 1990;Parton, Bradshaw, Davies, & Rogers, 1996;Rogers & Graham, 1983).…”