TY - JOUR
T1 - Interocular orientation disparity and the stereoscopic perception of slanted surfaces
AU - Heeley, D. W.
AU - Scott-Brown, Kenneth C.
AU - Reid, G.
AU - Maitland, F.
PY - 2003
Y1 - 2003
N2 - The orientation threshold for two-dimensional filtered noise stimuli was estimated using forced-choice procedures with both dioptic and dichoptic viewing. In the dioptic case the two patterns were co-rotated. In the dichoptic case the stimuli were counter-rotated to produce an orientation disparity, which yields a percept of slant about the horizontal axis orthogonal to the cyclopean line of sight. Dioptic thresholds increased with the orientation bandwidth of the stimuli. In contrast, dichoptic thresholds were essentially constant across a wide range of conditions. In all cases, dichoptic orientation acuity was much finer than conventional estimates. In a second experiment, the dichoptic threshold was estimated for patterns superimposed on a depth pedestal. Acuity was affected significantly by the presence of the pedestal, and was an inverse function of pedestal amplitude. The results suggest that stereoscopic slant caused by dichoptic counter-rotation arises because of neural processing of the overall pattern of disparities of position produced by counter-rotation, rather than specialised encoding of orientation disparity.
AB - The orientation threshold for two-dimensional filtered noise stimuli was estimated using forced-choice procedures with both dioptic and dichoptic viewing. In the dioptic case the two patterns were co-rotated. In the dichoptic case the stimuli were counter-rotated to produce an orientation disparity, which yields a percept of slant about the horizontal axis orthogonal to the cyclopean line of sight. Dioptic thresholds increased with the orientation bandwidth of the stimuli. In contrast, dichoptic thresholds were essentially constant across a wide range of conditions. In all cases, dichoptic orientation acuity was much finer than conventional estimates. In a second experiment, the dichoptic threshold was estimated for patterns superimposed on a depth pedestal. Acuity was affected significantly by the presence of the pedestal, and was an inverse function of pedestal amplitude. The results suggest that stereoscopic slant caused by dichoptic counter-rotation arises because of neural processing of the overall pattern of disparities of position produced by counter-rotation, rather than specialised encoding of orientation disparity.
U2 - 10.1163/15685680360511663
DO - 10.1163/15685680360511663
M3 - Article
VL - 16
SP - 183
EP - 207
JO - Multisensory research
JF - Multisensory research
SN - 2213-4794
IS - 2
ER -