scholarly journals Why is horizontal disparity important for stereo depth?

2018 ◽  
Vol 18 (10) ◽  
pp. 991
Author(s):  
Bart Farell ◽  
Cherlyn Ng
Keyword(s):  
Horizontal Disparity

The Interpretation of Stereo-Disparity Information: The Computation of Surface Orientation and Depth

Perception ◽  
1982 ◽  
Vol 11 (4) ◽  
pp. 387-407 ◽  
Author(s):  
John Mayhew
Keyword(s):  
Surface Orientation ◽  
The Other ◽  
Surface Patch ◽  
Viewing Distance ◽  
Horizontal Disparity ◽  
Planar Surface ◽  
Local Surface ◽  
Stereo Disparity ◽  
The Gaze ◽  
Perceptual Phenomenon

Two methods for interpreting disparity information are described. Neither requires extraretinal information to scale for distance: one method uses horizontal disparities to solve for the viewing distance, the other uses the vertical disparities. Method 1 requires the assumption that the disparities derive from a locally planar surface. Then from the horizontal disparities measured at four retinal locations the viewing distance and the equation of local surface ‘patch’ can be obtained. Method 2 does not need this assumption. The vertical disparities are first used to obtain the values of the gaze and viewing distance. These are then used to interpret the horizontal disparity information. An algorithm implementing the methods has been tested and is found to be subject to a perceptual phenomenon known as the ‘induced effect’.

Infants Perceive Three-Dimensional Subjective Contours

Perception ◽  
2018 ◽  
Vol 47 (12) ◽  
pp. 1153-1165 ◽  
Author(s):  
Michael Kavšek ◽  
Stephanie Braun
Keyword(s):  
Three Dimensional ◽  
Two Dimensional ◽  
Illusory Effect ◽  
Horizontal Disparity ◽  
Illusory Contours ◽  
Kanizsa Figure

The addition of crossed horizontal disparity enhances the clarity of illusory contours compared to pictorial illusory contours and illusory contours with uncrossed horizontal disparity. Two infant-controlled habituation–dishabituation experiments explored the presence of this effect in infants 5 months of age. Experiment 1 examined whether infants are able to distinguish between a Kanizsa figure with crossed horizontal disparity and a Kanizsa figure with uncrossed horizontal disparity. Experiment 2 tested infants for their ability to differentiate between a Kanizsa figure with crossed horizontal disparity and a two-dimensional Kanizsa figure. The results provided evidence that the participants perceived the two- and the three-dimensional illusory Kanizsa contour, the illusory effect in which was strengthened by the addition of crossed horizontal disparity.

Gain of Human Torsional Optokinetic Nystagmus Depends on Horizontal Disparity

2005 ◽  
Vol 46 (1) ◽  
pp. 133
Author(s):  
Noriaki Washio ◽  
Yasuo Suzuki ◽  
Masahiro Sawa ◽  
Kenji Ohtsuka
Keyword(s):  
Optokinetic Nystagmus ◽  
Horizontal Disparity

scholarly journals Understanding the Cortical Specialization for Horizontal Disparity

2004 ◽  
Vol 16 (10) ◽  
pp. 1983-2020 ◽  
Author(s):  
Jenny C.A. Read ◽  
Bruce G. Cumming
Keyword(s):  
Orientation Tuning ◽  
Horizontal Disparity ◽  
Vertical Disparity ◽  
V1 Neurons ◽  
Relative Response ◽  
Response Range ◽  
Divisive Normalization ◽  
Identical Position ◽  
Recent Experimental Work ◽  
To Receive

Because the eyes are displaced horizontally, binocular vision is inherently anisotropic. Recent experimental work has uncovered evidence of this anisotropy in primary visual cortex (V1): neurons respond over a wider range of horizontal than vertical disparity, regardless of their orientation tuning. This probably reflects the horizontally elongated distribution of two-dimensional disparity experienced by the visual system, but it conflicts with all existing models of disparity selectivity, in which the relative response range to vertical and horizontal disparities is determined by the preferred orientation. Potentially, this discrepancy could require us to abandon the widely held view that processing in V1 neurons is initially linear. Here, we show that these new experimental data can be reconciled with an initial linear stage; we present two physiologically plausible ways of extending existing models to achieve this. First, we allow neurons to receive input from multiple binocular subunits with different position disparities (previous models have assumed all subunits have identical position and phase disparity). Then we incorporate a form of divisive normalization, which has successfully explained many response properties of V1 neurons but has not previously been incorporated into a model of disparity selectivity. We show that either of these mechanisms decouples disparity tuning from orientation tuning and discuss how the models could be tested experimentally. This represents the first explanation of how the cortical specialization for horizontal disparity may be achieved.

Orientation preference and horizontal disparity sensitivity in the monkey visual cortex

2010 ◽  
Vol 30 (6) ◽  
pp. 824-833 ◽  
Author(s):  
Francisco Gonzalez ◽  
Maria A. Bermudez ◽  
Ana F. Vicente ◽  
Maria C. Romero
Keyword(s):  
Visual Cortex ◽  
Horizontal Disparity ◽  
Orientation Preference ◽  
Monkey Visual Cortex

Encoding of both vertical and horizontal disparity in random-dot stereograms by Wulst neurons of awake barn owls

2001 ◽  
Vol 18 (4) ◽  
pp. 541-547 ◽  
Author(s):  
ANDREAS NIEDER ◽  
HERMANN WAGNER
Keyword(s):  
Lateral Displacement ◽  
Two Dimensions ◽  
Orientation Tuning ◽  
Main Peak ◽  
Horizontal Disparity ◽  
Vertical Disparity ◽  
Tuning Curves ◽  
Random Dot Stereograms ◽  
Barn Owls ◽  
Stimulus Offset

In binocular vision, the lateral displacement of the eyes gives rise to both horizontal and vertical disparities between the images projected onto the left and right retinae. While it is well known that horizontal disparity is exploited by the binocular visual system of birds and mammals to enable depth perception, the role of vertical disparity is still largely unclear. In this study, neuronal activity in the visual forebrain (visual Wulst) of behaving barn owls to vertical disparity was investigated. Single-unit responses to global random-dot stereograms (RDS) were recorded with chronically implanted electrodes and transmitted via radiotelemetry. Nearly half of the cells investigated (44%, 16/36) varied the discharge as a function of vertical disparity. Like horizontal-disparity tuning profiles, vertical-disparity tuning curves typically exhibited periodic modulation with side peaks flanking a prominent main peak, and thus, could be fitted well with a Gabor function. This indicates that tuning to vertical disparity was not caused by disrupting horizontal-disparity tuning via vertical stimulus offset, but by classical disparity detectors whose orientation tuning was tilted. When tested with horizontal in addition to vertical disparity, almost all cells investigated (92%, 12/13) were tuned to both kinds of disparity. The emergence of disparity detectors sensitive in two dimensions (horizontal and vertical) is discussed within the framework of the disparity energy model.

Quantitative Analysis of the Responses of V1 Neurons to Horizontal Disparity in Dynamic Random-Dot Stereograms

2002 ◽  
Vol 87 (1) ◽  
pp. 191-208 ◽  
Author(s):  
S.J.D. Prince ◽  
A. D. Pointon ◽  
B. G. Cumming ◽  
A. J. Parker
Keyword(s):  
Spatial Frequency ◽  
Tuning Curve ◽  
Ocular Dominance ◽  
Large Population ◽  
Gaussian Function ◽  
Energy Model ◽  
Horizontal Disparity ◽  
Orientation Preference ◽  
Tuning Curves ◽  
Random Dot Stereograms

Horizontal disparity tuning for dynamic random-dot stereograms was investigated for a large population of neurons ( n = 787) in V1 of the awake macaque. Disparity sensitivity was quantified using a measure of the discriminability of the maximum and minimum points on the disparity tuning curve. This measure and others revealed a continuum of selectivity rather than separate populations of disparity- and nondisparity-sensitive neurons. Although disparity sensitivity was correlated with the degree of direction tuning, it was not correlated with other significant neuronal properties, including preferred orientation and ocular dominance. In accordance with the Gabor energy model, tuning curves for horizontal disparity were adequately described by Gabor functions when the neuron's orientation preference was near vertical. For neurons with orientation preferences near to horizontal, a Gaussian function was more frequently sufficient. The spatial frequency of the Gabor function that described the disparity tuning was weakly correlated with measurements of the spatial frequency and orientation preference of the neuron for drifting sinusoidal gratings. Energy models make several predictions about the relationship between the response rates to monocular and binocular dot patterns. Few of the predictions were fulfilled exactly, although the observations can be reconciled with the energy model by simple modifications. These same modifications also provide an account of the observed continuum in strength of disparity selectivity. A weak correlation between the disparity sensitivity of simultaneously recorded single- and multiunit data were revealed as well as a weak tendency to show similar disparity preferences. This is compatible with a degree of local clustering for disparity sensitivity in V1, although this is much weaker than that reported in area MT.

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