scholarly journals First- and second-order contributions to depth perception in anti-correlated random dot stereograms

2018 ◽  
Author(s):  
Jordi M. Asher ◽  
Paul B. Hibbard
Keyword(s):  
Binocular Disparity ◽  
Second Order ◽  
Gap Size ◽  
Neural Responses ◽  
Random Dot Stereograms ◽  
Coarse Spatial Resolution ◽  
Correct Direction ◽  
Random Dot Stereogram ◽  
Circular Target ◽  
Detection Mechanisms

ABSTRACTThe binocular energy model of neural responses predicts that depth from binocular disparity might be perceived in the reversed direction when the contrast of dots presented to one eye is reversed. While reversed depth has been found using anti-correlated random-dot stereogram (ACRDS) the findings are inconsistent across studies. The mixed findings may be accounted for by the presence of a gap between the target and surround, or as a result of overlap of dots around the vertical edges of the stimuli. To test this, we assessed whether (1) the gap size (0, 19.2 or 38.4 arc min) (2) the correlation of dots or (3) the border orientation (circular target, or horizontal or vertical edge) affected the perception of depth. Reversed depth from ACRDS (circular no-gap condition) was seen by a minority of participants, but this effect reduced as the gap size increased. Depth was mostly perceived in the correct direction for ACRDS edge stimuli, with the effect increasing with the gap size. The inconsistency across conditions can be accounted for by the relative reliability of first- and second-order depth detection mechanisms, and the coarse spatial resolution of the latter.

Binocular Utilization of Monocular Cues That are Undetectable Monocularly

Perception ◽  
1978 ◽  
Vol 7 (3) ◽  
pp. 315-322 ◽  
Author(s):  
Bela Julesz ◽  
Hans-Peter Oswald
Keyword(s):  
Eye Movements ◽  
Binocular Disparity ◽  
Detection Threshold ◽  
Density Difference ◽  
Latency Time ◽  
Wide Range ◽  
Random Dot Stereograms ◽  
Perception Time ◽  
Dot Density ◽  
Random Dot Stereogram

The latency time of tracking dynamic random-dot stereograms can be shortened by as much as 100 ms when monocular cues are added by introducing a difference in dot density between target and surround. It has been tacitly assumed that perception time will be reduced only if the added monocular cues are above the detection threshold for each eye. However, the experiments reported here clearly show that stereoscopic performance as measured by an eye tracking task can be greatly enhanced by added monocular cues that cannot be detected. Observers were instructed to track a suddenly displaced vertical bar (portrayed as a dynamic random-dot stereogram) while their eye movements were recorded by EOG. The bar had either a given binocular disparity or zero binocular disparity with respect to its surround. For the target with a disparity (in a wide range), the latency time of tracking decreased by more than 30 ms (10%) as density difference increased from 0 to 4%, whereas in the control conditions with no stereoscopic cues (zero disparity) subjects were unable to track the bar at all within that range of density difference. Thus stereopsis is greatly aided by minimal monocular cues that by themselves elude monocular detection.

Assessing the Role of Vergence Changes in the Perception of Random-Dot Stereograms by Using Open-Loop Control of Vergence

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 131-131 ◽  
Author(s):  
B J Rogers ◽  
M F Bradshaw
Keyword(s):  
Open Loop ◽  
Open Loop Control ◽  
Complex Surfaces ◽  
Loop Control ◽  
Random Dot Stereograms ◽  
Disparity Range ◽  
The Difference ◽  
Random Dot Stereogram ◽  
University Of Chicago Press

The fact that the 3-D shape of surfaces depicted by random dot stereograms can take several seconds or even tens of seconds to appear has been attributed to the failure to make appropriate vergence changes [B Julesz, 1971 Foundations of Cyclopean Perception (Chicago, IL: University of Chicago Press)]. Alternatively, the long latencies could be a consequence of the processing time needed to match the disparate images. To distinguish between these possibilities we measured perceptual latencies in a situation in which vergence changes had no effect on retinal disparities. To do this, horizontal eye movements were recorded with the aid of close-fitting scleral search coils in both eyes and the difference signal used to shift horizontally the two halves of a random-dot stereogram by equal and opposite amounts. When the amount of shift was equal to the magnitude of the vergence change, changes of vergence had no effect on the pattern of disparities—open-loop vergence. Three observers were presented with a sequence of stereograms depicting both ‘simple’ surfaces (a single square lying in front of the surround) and ‘complex’ surfaces, including spirals, ‘wedding cakes’, and saddle shapes under both normal and open-loop conditions. Under open-loop conditions, the complete 3-D shape was never perceived when the disparity range of the stereogram was large (>40 min arc), demonstrating the necessity of vergence changes, but the 3-D structure of ‘complex’ surfaces did build up over a period of several seconds indicating a separate disparity processing limitation.

scholarly journals Stimulus Dependence of Disparity Coding in Primate Visual Area V4

2005 ◽  
Vol 93 (1) ◽  
pp. 620-626 ◽  
Author(s):  
Jay Hegdé ◽  
David C. Van Essen
Keyword(s):  
Binocular Disparity ◽  
Three Dimensional ◽  
Visual Area ◽  
Tuning Curves ◽  
Depth Cues ◽  
Area V4 ◽  
Random Dot Stereograms ◽  
Dimensional Shape ◽  
Visual Area V4 ◽  
Three Dimensional Shape

Disparity tuning in visual cortex has been shown using a variety of stimulus types that contain stereoscopic depth cues. It is not known whether different stimuli yield similar disparity tuning curves. We studied whether cells in visual area V4 of the macaque show similar disparity tuning profiles when the same set of disparity values were tested using bars or dynamic random dot stereograms, which are among the most commonly used stimuli for this purpose. In a majority of V4 cells (61%), the shape of the disparity tuning profile differed significantly for the two stimulus types. The two sets of stimuli yielded statistically indistinguishable disparity tuning profiles for only a small minority (6%) of V4 cells. These results indicate that disparity tuning in V4 is stimulus-dependent. Given the fact that bar stimuli contain two-dimensional (2-D) shape cues, and the random dot stereograms do not, our results also indicate that V4 cells represent 2-D shape and binocular disparity in an interdependent fashion, revealing an unexpected complexity in the analysis of depth and three-dimensional shape.

scholarly journals Processing of first and second order binocular disparity by the human visual system

2012 ◽  
Vol 12 (9) ◽  
pp. 39-39
Author(s):  
C. Quaia ◽  
B. Sheliga ◽  
L. Optican ◽  
B. Cumming
Keyword(s):  
Visual System ◽  
Human Visual System ◽  
Binocular Disparity ◽  
Second Order

How is Depth Perception Affected by Long-Term Wearing of Left-Right Reversing Spectacles?

Perception ◽  
1993 ◽  
Vol 22 (8) ◽  
pp. 971-984 ◽  
Author(s):  
Makoto Ichikawa ◽  
Hiroyuki Egusa
Keyword(s):  
Depth Perception ◽  
Binocular Disparity ◽  
Depth Cues ◽  
Directional Relation ◽  
Random Dot Stereogram ◽  
Binocular Depth

The plasticity of binocular depth perception was investigated. Six subjects wore left-right reversing spectacles continuously for 10 or 11 days. On looking through the spectacles, the relation between the direction of physical depth (convex or concave) and the direction of binocular disparity (crossed or uncrossed) was reversed, but other depth cues did not change. When subjects observed stereograms through a haploscope and were asked to judge the direction of perceived depth, the directional relation between perceived depth and disparity was reversed both in the two line-contoured stereograms and in the random-dot stereogram in the middle of the wearing period, but the normal relation often returned late in the wearing period. When subjects observed two objects while wearing the spectacles and were asked which appeared the nearer, veridical depth perception increased as the wearing-time passed. These results indicate that the visual transformation reversing the direction of binocular disparity causes changes both in binocular stereopsis and in processes integrating different depth cues.

Second-order neural responses after contralateral vestibular nerve sectioning

1983 ◽  
Vol 4 (2) ◽  
pp. 101-106 ◽  
Author(s):  
Richard W. Babin ◽  
Jai H. Ryu ◽  
Brian F. McCabe
Keyword(s):  
Second Order ◽  
Vestibular Nerve ◽  
Neural Responses

Effect of Spatial Structure Defined by Binocular Disparity with Uniform Luminance on Lightness

Perception ◽  
2019 ◽  
Vol 49 (1) ◽  
pp. 3-20
Author(s):  
Kei Kanari ◽  
Hirohiko Kaneko
Keyword(s):  
Spatial Structure ◽  
Visual System ◽  
Uniform Distribution ◽  
Binocular Disparity ◽  
Stimulus Space ◽  
Luminance Distribution ◽  
Scene Structure ◽  
Structure Relation ◽  
Random Dot Stereogram ◽  
The Relationship

We examined whether lightness is determined based on the experience of the relationship between a scene’s illumination and its spatial structure in actual environments. For this purpose, we measured some characteristics of scene structure and the illuminance in actual scenes and found some correlations between them. In the psychophysical experiments, a random-dot stereogram consisting of dots with uniform distribution was used to eliminate the effects of local luminance and texture contrasts. Participants matched the lightness of a presented target patch in the stimulus space to that of a comparison patch by adjusting the latter’s luminance. Results showed that the matched luminance tended to increase when the target patch was interpreted as receiving weak illumination in some conditions. These results suggest that the visual system can probably infer a scene’s illumination from a spatial structure without luminance distribution information under an illumination–spatial structure relation.

Stereoscopic Illusion Based on the Proximity Principle

Perception ◽  
1989 ◽  
Vol 18 (5) ◽  
pp. 589-594 ◽  
Author(s):  
Thomas V Papathomas ◽  
Bela Julesz
Keyword(s):  
Binocular Disparity ◽  
Interesting Property ◽  
Temporal Sequence ◽  
Horizontal Direction ◽  
Periodic Stimulus ◽  
Random Dot Stereograms ◽  
Depth Percept ◽  
Proximity Principle ◽  
Random Dot Pattern ◽  
Sawtooth Waveform

A class of ambiguous random-dot stereograms were created that share the following interesting property: Although the binocular disparity forms a periodic ‘sawtooth’ waveform as a function of row number (the disparity is constant for a given row), these stimuli yield a monotonically increasing depth percept along the rows. The random-dot pattern of each row is periodic along the horizontal direction for the purpose of producing an ambiguous depth percept. It is this ambiguity that makes it possible for the periodic stimulus to give rise to a monotonic percept. This monotonic percept is substantially enhanced when the rows are shown in temporal sequence instead of all being displayed together. Experiments are reported which indicate that this illusion is due to the proximity, or pulling, effect in stereopsis.

scholarly journals Reversed depth in anti-correlated random dot stereograms and central-peripheral difference in visual inference

2017 ◽  
Author(s):  
Li Zhaoping ◽  
Joelle Ackermann
Keyword(s):  
Great Difficulty ◽  
Black Dot ◽  
Black And White ◽  
Cortical Areas ◽  
Visual Areas ◽  
Random Dot Stereograms ◽  
Monocular Image ◽  
Random Dot Stereogram ◽  
Visual Cortical ◽  
Higher Visual Areas

1AbstractTwo images of random black and white dots, one for each eye, can represent object surfaces in a threedimensional scene when the dots correspond interocularly in a random dot stereogram (RDS). The spatial disparities between the corresponding dots represent depths of object surfaces. If the dots become anti-correlated such that a black dot in one monocular image corresponds to a white dot in the other, disparity-tuned neurons in the primary visual cortex (V1) respond as if their preferred disparities become non-preferred and vice versa, thereby reversing the disparity signs reported to higher visual areas. Humans have great difficulty perceiving the reversed depth, or any depth at all, in anti-correlated RDSs. We report that the reversed depth is more easily perceived when the RDSs are viewed in peripheral visual field, supporting a recently proposed central-peripheral dichotomy in mechanisms of feedback from higher to lower visual cortical areas for visual inference.

Visual Inter-Attribute Contour Completion

Perception ◽  
10.1068/p3222 ◽  
2001 ◽  
Vol 30 (7) ◽  
pp. 855-865 ◽  
Author(s):  
Leo Poom
Keyword(s):  
Binocular Disparity ◽  
Luminance Contrast ◽  
Second Order ◽  
Temporal Contrast ◽  
Pictorial Cues ◽  
Visual Phenomenon ◽  
Completion Process ◽  
Contour Completion

A new visual phenomenon, inter-attribute illusory (completed) contours, is demonstrated. Contour completions are perceived between any combination of spatially separate pairs of inducing elements (Kanizsa-like ‘pacman’ figures) defined either by pictorial cues (luminance contrast or offset gratings), temporal contrast (motion, second-order-motion or ‘phantom’ contours), or binocular-disparity contrast. In a first experiment, observers reported the perceived occurrence of contour completion for all pair combinations of inducing elements. In a second experiment they rated the perceived clarity of the completed contours. Both methods generated similar results—contour completions were perceived even though the inducing elements were defined by different attributes. Ratings of inter-attribute clarity were no lower than in either of the two corresponding intra-attribute conditions and seem to be the average of these two ratings. The results provide evidence for the existence of attribute-invariant Gestalt processes, and on a mechanistic level indicate that the completion process operates on attribute-invariant contour detectors.

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