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 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.

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.

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.

Stereoscopic Discrimination in Infants

Perception ◽  
1976 ◽  
Vol 5 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Janette Atkinson ◽  
Oliver Braddick
Keyword(s):  
Longitudinal Studies ◽  
Binocular Disparity ◽  
High Amplitude ◽  
Stereoscopic Vision ◽  
Random Dot Stereograms ◽  
Fixation Preference

The ability to make discriminations of binocular disparity was investigated in 2-month-old infants by two methods: (a) fixation preference between patterns differing in the disparity they contained, and (b) recovery from habituation of high-amplitude sucking when there was a change in disparity in the visual reinforcer. The stimuli were random-dot stereograms. The results for both methods indicated that at least some infants of this age could perform stereoscopic discriminations and that both techniques were feasible for development for longitudinal studies of stereoscopic vision.

Binocular-Disparity-Dependent Upper—Lower Hemifield Anisotropy and Left—Right Hemifield Isotropy as Revealed by Dynamic Random-Dot Stereograms

Perception ◽  
1976 ◽  
Vol 5 (2) ◽  
pp. 129-141 ◽  
Author(s):  
Bela Julesz ◽  
Bruno Breitmeyer ◽  
Walter Kropfl
Keyword(s):  
Spatial Resolution ◽  
Binocular Disparity ◽  
Human Cortex ◽  
Tilted Surface ◽  
Random Dot Stereograms ◽  
Fixation Marker ◽  
Left And Right ◽  
Temporal And Spatial ◽  
Monocular Depth ◽  
Visual Hemifields

Dynamic random-dot stereograms devoid of all monocular depth cues were used to measure the limits of temporal and spatial resolution in the center of the visual field. The temporal durations for detecting a small, briefly presented test square of different binocular disparity than the surround varied as a function of its location and binocular disparity. The test squares presented in the upper hemifield were detectable at consistently shorter durations than those presented in the lower hemifield for a surround disparity which was uncrossed relative to the fixation marker. For crossed surround disparity this preference reversed, resulting in a superiority of the lower hemifield. The anisotropy diminished for zero surround disparity. No such anisotropy was found when left and right visual hemifields were compared. It was also shown that this upper—lower temporal anisotropy (and left—right isotropy) is paralleled by a similar disparity-dependent upper—lower anisotropy (and left—right isotropy) in spatial resolution. Introduction of monocular clues into the stereograms tended to eliminate the anisotropics. This implies that the anisotropics reflect the spatiotemporal properties and distribution of binocular disparity detectors in the human cortex and result in a tilted surface that pivots around the horizontal midline in the space of binocular depth perception.

Computing Stereo Disparity and Motion with Known Binocular Cell Properties

1994 ◽  
Vol 6 (3) ◽  
pp. 390-404 ◽  
Author(s):  
Ning Qian
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Stereo Vision ◽  
Motion Detection ◽  
Binocular Disparity ◽  
Stereo Disparity ◽  
Random Dot Stereograms ◽  
Disparity Maps ◽  
Physiological Studies

Many models for stereo disparity computation have been proposed, but few can be said to be truly biological. There is also a rich literature devoted to physiological studies of stereopsis. Cells sensitive to binocular disparity have been found in the visual cortex, but it is not clear whether these cells could be used to compute disparity maps from stereograms. Here we propose a model for biological stereo vision based on known receptive field profiles of binocular cells in the visual cortex and provide the first demonstration that these cells could effectively solve random dot stereograms. Our model also allows a natural integration of stereo vision and motion detection. This may help explain the existence of units tuned to both disparity and motion in the visual cortex.

scholarly journals Disparity sensitivity and binocular integration in mouse visual cortex areas

2020 ◽  
Author(s):  
Alessandro La Chioma ◽  
Tobias Bonhoeffer ◽  
Mark Hübener
Keyword(s):  
Visual Cortex ◽  
Binocular Disparity ◽  
Spatial Clustering ◽  
Ocular Dominance ◽  
Three Dimensional ◽  
Strong Response ◽  
Visual Stream ◽  
Visual Areas ◽  
The Difference ◽  
Depth Percept

AbstractBinocular disparity, the difference between the two eyes’ images, is a powerful cue to generate the three-dimensional depth percept known as stereopsis. In primates, binocular disparity is processed in multiple areas of the visual cortex, with distinct contributions of higher areas to specific aspects of depth perception. Mice, too, can perceive stereoscopic depth, and neurons in primary visual cortex (V1) and higher-order, lateromedial (LM) and rostrolateral (RL) areas were found to be sensitive to binocular disparity. A detailed characterization of disparity tuning properties across mouse visual areas is lacking, however, and acquiring such data might help clarifying the role of higher areas for disparity processing and establishing putative functional correspondences to primate areas. We used two-photon calcium imaging to characterize the disparity tuning properties of neurons in mouse visual areas V1, LM, and RL in response to dichoptically presented binocular gratings, as well as correlated and anticorrelated random dot stereograms (RDS). In all three areas, many neurons were tuned to disparity, showing strong response facilitation or suppression at optimal or null disparity, respectively. This was even the case in neurons classified as monocular by conventional ocular dominance measurements. Spatial clustering of similarly tuned neurons was observed at a scale of about 10 μm. Finally, we probed neurons’ sensitivity to true stereo correspondence by comparing responses to correlated and anticorrelated RDS. Area LM, akin to primate ventral visual stream areas, showed higher selectivity for correlated stimuli and reduced anticorrelated responses, indicating higher-level disparity processing in LM compared to V1 and RL.

scholarly journals Processing of Shape Defined by Disparity in Monkey Inferior Temporal Cortex

2001 ◽  
Vol 85 (2) ◽  
pp. 735-744 ◽  
Author(s):  
Hiroki Tanaka ◽  
Takanori Uka ◽  
Kenji Yoshiyama ◽  
Makoto Kato ◽  
Ichiro Fujita
Keyword(s):  
Visual Cues ◽  
Binocular Disparity ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Response Modulation ◽  
Random Dot Stereograms ◽  
Fixation Task ◽  
Per Se ◽  
Extracellular Activity

Neurons in the monkey inferior temporal cortex (IT) have been shown to respond to shapes defined by luminance, texture, or motion. In the present study, we determined whether IT neurons respond to shapes defined solely by binocular disparity, and if so, whether signals of disparity and other visual cues to define shape converge on single IT neurons. We recorded extracellular activity from IT neurons while monkeys performed a fixation task. Among the neurons that responded to at least one of eight random-dot stereograms (RDSs) containing different disparity-defined shapes, 21% varied their responses to different RDSs. Responses of most of the neurons were positively correlated between two sets of RDSs, which consisted of different dot patterns but defined the same set of eight shapes, whereas responses to RDSs and their monocular images were not correlated. This indicates that the response modulation for the eight RDSs reflects selectivity for shapes (or their component contours) defined by disparity, although responses were also affected by dot patterns per se. Among the neurons that showed selectivity for shapes defined by luminance or disparity, 44% were activated by both cues. Responses of these neurons to luminance-defined shapes and those to disparity-defined shapes were often positively correlated to each other. Furthermore the stimulus rank, which was determined by the magnitude of responses to shapes, generally matched between these cues. The same held true between disparity and texture cues. The results suggest that the signals of disparity, luminance, and texture cues to define the shapes converge on a population of single IT neurons to produce the selectivity for shapes.

scholarly journals Learning to See Random-Dot Stereograms

Perception ◽  
1992 ◽  
Vol 21 (2) ◽  
pp. 227-243 ◽  
Author(s):  
Alice J O'Toole ◽  
Daniel J Kersten
Keyword(s):  
Learning Effects ◽  
Retinal Position ◽  
Selective Visual Attention ◽  
Random Dot Stereograms ◽  
Position Specificity ◽  
Random Dot Patterns ◽  
Depth Percept ◽  
Specificity Of Learning ◽  
Specific Learning

In the present study some specific properties of the learning effects reported for random-dot stereograms are examined. In experiment 1 the retinal position-specific learning effect was reproduced and in a follow-up experiment it was shown that the position specificity of learning can be accounted for by selective visual attention. In experiments 2 and 3 evidence was obtained that suggests that observers can learn, to a certain degree, monocular random-dot patterns and that this learning facilitates the depth percept. This result indicates that the traditional belief that random-dot stereograms are devoid of monocularly recognizable or useful forms should be reconsidered. In the second set of experiments the learning of two binocular surface properties of random-dot stereograms, depth edges and internal depth regions, was investigated. It was shown in experiment 4 that the depth edges of random-dot stereograms are not learned, whereas the results of experiment 5 indicate that the internal depth regions are learned. Finally, in experiment 6 it was shown that depth edges are learned when the internal depth regions of the stereogram are ambiguous. The results are discussed in terms of the importance of the particular type of stimulus used in the learning process and in terms of perceptual learning and attention.

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