Stereoscopic Depth Sensitivity Differences between the Crossed and Uncrossed Directions

This study investigated the temporal sensitivity of crossed and uncrossed stereoscopic mechanisms of 48 observers using stimuli created from dynamic random-dot stereograms. The results showed thresholds were lower and depth was more veridical in the crossed than in the uncrossed direction.

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Disparity-Tuning Characteristics of Neuronal Responses to Dynamic Random-Dot Stereograms in Macaque Visual Area V4

Journal of Neurophysiology ◽

10.1152/jn.00319.2005 ◽

2005 ◽

Vol 94 (4) ◽

pp. 2683-2699 ◽

Cited By ~ 36

Author(s):

Seiji Tanabe ◽

Takahiro Doi ◽

Kazumasa Umeda ◽

Ichiro Fujita

Keyword(s):

Striate Cortex ◽

Broad Band ◽

Structural Features ◽

Stereoscopic Depth ◽

Tuning Curves ◽

Gabor Function ◽

Area V4 ◽

Random Dot Stereograms ◽

Response Preferences ◽

V4 Neurons

Stereo processing begins in the striate cortex and involves several extrastriate visual areas. We quantitatively analyzed the disparity-tuning characteristics of neurons in area V4 of awake, fixating monkeys. Approximately half of the analyzed V4 cells were tuned for horizontal binocular disparities embedded in dynamic random-dot stereograms (RDSs). Their response preferences were strongly biased for crossed disparities. To characterize the disparity-tuning profile, we fitted a Gabor function to the disparity-tuning data. The distribution of V4 cells showed a single dense cluster in a joint parameter space of the center and the phase parameters of the fitted Gabor function; most V4 neurons were maximally sensitive to fine stereoscopic depth increments near zero disparity. Comparing single-cell responses with background multiunit responses at the same sites showed that disparity-sensitive cells were clustered within V4 and that nearby cells possessed similar preferred disparities. Consistent with a recent report by Hegdé and Van Essen, the disparity tuning for an RDS drastically differed from that for a solid-figure stereogram (SFS). Disparity-tuning curves were generally broader for SFSs than for RDSs, and there was no correlation between the fitted Gabor functions' amplitudes, widths, or peaks for the two types of stereograms. The differences were partially attributable to shifts in the monocular images of an SFS. Our results suggest that the representation of stereoscopic depth in V4 is suited for detecting fine structural features protruding from a background. The representation is not generic and differs when the stimulus is broad-band noise or a solid figure.

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Adaptation to the Reversal of Binocular Depth Cues: Effects of Wearing Left-Right Reversing Spectacles on Stereoscopic Depth Perception

Perception ◽

10.1068/p100391 ◽

1981 ◽

Vol 10 (4) ◽

pp. 391-402 ◽

Cited By ~ 22

Author(s):

Shinsuke Shimojo ◽

Yoshitaka Nakajima

Keyword(s):

Depth Perception ◽

Neural Mechanism ◽

Adaptive Change ◽

Stereoscopic Depth ◽

Depth Cues ◽

Uncrossed Disparity ◽

Random Dot Stereograms ◽

Long Time ◽

Binocular Depth

The principle of stereopsis, that crossed disparity causes a convex perception and uncrossed disparity a concave one, has for a long time been considered to depend on a very rigid neural mechanism not affected by experience. Experiments are reported here which show that this relationship between disparity and perceived depth can be reversed by experience. An observer wore a pair of left-right reversing spectacles continuously for nine days. The spectacles also reversed the relation between the direction of perceived depth and the direction of binocular depth cues, ie disparity and vergence. For a period starting two days before wearing the spectacles and continuing until seventy-nine days after their removal the observer was examined with a haploscope and an electrooculograph. All the stereoscopic experiments were carried out without spectacles in order to examine some aftereffects of wearing spectacles. For the stereograms with linear contours not only the adaptive reversal of the relation between disparity and perceived depth, but also some abnormal depth perceptions and long-lasting aftereffects were found. For Julesz's random-dot stereograms, however, in which contours can be seen only after binocular combination, no adaptive change or reversal occurred. These results suggest that the process of stereopsis consists of two concurrent subprocesses.

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Human Depth Sensitivity Is Affected by Object Plausibility

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_01483 ◽

2020 ◽

Vol 32 (2) ◽

pp. 338-352

Author(s):

Nicole H. L. Wong ◽

Hiroshi Ban ◽

Dorita H. F. Chang

Keyword(s):

Euclidean Geometry ◽

Judgment Task ◽

Depth Information ◽

Neural Responses ◽

Behavioral Thresholds ◽

Depth Position ◽

Geometric Objects ◽

Random Dot Stereograms ◽

Object Familiarity ◽

Depth Sensitivity

Using behavioral and fMRI paradigms, we asked how the physical plausibility of complex 3-D objects, as defined by the object's congruence with 3-D Euclidean geometry, affects behavioral thresholds and neural responses to depth information. Stimuli were disparity-defined geometric objects rendered as random dot stereograms, presented in plausible and implausible variations. In the behavior experiment, observers were asked to complete (1) a noise-based depth task that involved judging the depth position of a target embedded in noise and (2) a fine depth judgment task that involved discriminating the nearer of two consecutively presented targets. Interestingly, results indicated greater behavioral sensitivities of depth judgments for implausible versus plausible objects across both tasks. In the fMRI experiment, we measured fMRI responses concurrently with behavioral depth responses. Although univariate responses for depth judgments were largely similar across cortex regardless of object plausibility, multivariate representations for plausible and implausible objects were notably distinguishable along depth-relevant intermediate regions V3 and V3A, in addition to object-relevant LOC. Our data indicate significant modulations of both behavioral judgments of and neural responses to depth by object context. We conjecture that disparity mechanisms interact dynamically with the object recognition problem in the visual system such that disparity computations are adjusted based on object familiarity.

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Colour Inputs to Random-Dot Stereopsis

Perception ◽

10.1068/p210717 ◽

1992 ◽

Vol 21 (6) ◽

pp. 717-729 ◽

Cited By ~ 16

Author(s):

Geoffrey W Stuart ◽

Mark Edwards ◽

Michael L Cook

Keyword(s):

Luminance Contrast ◽

Stereoscopic Depth ◽

Signal To Noise ◽

Chromatic Contrast ◽

Magnocellular System ◽

Colour Contrast ◽

Random Dot Stereograms ◽

Photoreceptor Mosaic

Recently it has been claimed by Livingstone and Hubel that, of three anatomically and functionally distinct visual channels (the magnocellular, parvocellular interblob, and blob channels), only the magnocellular channel is involved in the processing of stereoscopic depth. Since the magnocellular system shows little overt colour opponency, the reported loss of the ability to resolve random-dot stereograms defined only by colour contrast seems consistent with this view. However, Julesz observed that reversed-contrast stereograms could be fused if correlated colour information was added. In the present study, ‘noise’ (non-corresponding) pixels were injected into random-dot stereograms in order to increase fusion time. All six subjects tested were able to achieve stereopsis in less than three minutes when there was only correspondence in colour and not in luminance, and three when luminance contrast was completely reversed. This ability depends on information about the direction of colour contrast, not just the presence of chromatic borders. When luminance and chromatic contrast are defined in terms of signal-to-noise ratios at the photoreceptor mosaic, chromatic information plays at least as important a role in stereopsis as does luminance information, suggesting that the magnocellular channel is not uniquely involved.

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On Stereoscopic Art

i-Perception ◽

10.1177/20416695211007146 ◽

2021 ◽

Vol 12 (3) ◽

pp. 204166952110071

Author(s):

Nicholas J. Wade

Keyword(s):

Picture Plane ◽

Early History ◽

Stereoscopic Depth ◽

Two Dimensional ◽

Art Works ◽

Pictorial Cues ◽

Random Dot Stereograms ◽

History Of

Pictorial art is typically viewed with two eyes, but it is not binocular in the sense that it requires two eyes to appreciate the art. Two-dimensional representational art works allude to depth that they do not contain, and a variety of stratagems is enlisted to convey the impression that surfaces on the picture plane are at different distances from the viewer. With the invention of the stereoscope by Wheatstone in the 1830s, it was possible to produce two pictures with defined horizontal disparities between them to create a novel impression of depth. Stereoscopy and photography were made public at about the same time and their marriage was soon cemented; most stereoscopic art is now photographic. Wheatstone sought to examine stereoscopic depth without monocular pictorial cues. He was unable to do this, but it was achieved a century later by Julesz with random-dot stereograms The early history of non-photographic stereoscopic art is described as well as reference to some contemporary works. Novel stereograms employing a wider variety of carrier patterns than random dots are presented as anaglyphs; they show modulations of pictorial surface depths as well as inclusions within a binocular picture.

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Perceived Frontal Size as a Determiner of Perceived Stereoscopic Depth

PsycEXTRA Dataset ◽

10.1037/e512302009-001 ◽

1957 ◽

Author(s):

W. C. Gogel

Keyword(s):

Stereoscopic Depth

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Expenditure-Based Indicators of Energy Poverty—An Analysis of Income and Expenditure Elasticities

Energies ◽

10.3390/en14010008 ◽

2020 ◽

Vol 14 (1) ◽

pp. 8

Author(s):

Johannes Thema ◽

Florin Vondung

Keyword(s):

Energy Expenditure ◽

Micro Data ◽

European Union Policy ◽

Energy Poverty ◽

Union Policy ◽

Depth Sensitivity ◽

Policy Agendas ◽

Poverty Indicators ◽

Specific Country ◽

The Eu

Energy poverty is high up on national and European Union policy agendas. A number of possible indicators to measure the issue have been identified in the literature, but comparable data with European coverage is scarce. The EU Commission thus proposes four independent indicators on the “EU Energy Poverty Observatory” based on self-reported items from the pan-European surveys on income and living conditions (SILC) and household budgets (HBS). It is of increasing public interest to analyse social impacts of energy policies, and quantify energy poverty indicators also from modelling. This paper first shortly outlines how the expenditure-based indicators using HBS micro data may be directly linked to existing macroeconomic models through their defining variables (energy expenditure and income). As endogenous modelling based on micro data is difficult, the link may be country-specific elasticities. The main contribution of the paper is a systematic in-depth sensitivity analysis of the two indicators to changes in income and energy expenditure following varying patterns in the underlying distributions of the micro data. The results may be used by future soft links to models. The results display sometimes counterintuitive effects. We find that whether these indicators increase/decrease after a change of income or energy expenditure largely depends on the specific country-wise income and energy expenditure distribution between households on a micro-level. Due to their definition, the examined indicators are especially sensitive, when income changes alter the indicator threshold values, which in these cases are the median values in underlying distributions. We discuss these findings and relate them to several indicator shortcomings and potential remedies through changes in indicator definition.

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