scholarly journals Overestimation of stereo thresholds by the TNO stereotest is not due to global stereopsis

2017 ◽  
Vol 37 (4) ◽  
pp. 507-520 ◽  
Author(s):  
Kathleen Vancleef ◽  
Jenny C. A. Read ◽  
William Herbert ◽  
Nicola Goodship ◽  
Maeve Woodhouse ◽  
...  
Keyword(s):  
Global Stereopsis

Global Stereopsis

1988 ◽  
pp. 427-430
Author(s):  
B. Julesz
Keyword(s):  
Global Stereopsis

Binocular visual processing in the owl’s telencephalon

1979 ◽  
Vol 204 (1157) ◽  
pp. 435-454 ◽  
Keyword(s):  
Visual Processing ◽  
Striate Cortex ◽  
Functional Organization ◽  
Receptive Fields ◽  
Field Size ◽  
Evolutionary Origins ◽  
Structural Differences ◽  
Output Neurons ◽  
Global Stereopsis ◽  
Orientation Movement

Single neurons recorded from the owl’s visual Wulst are surprisingly similar to those found in mammalian striate cortex. The receptive fields of Wulst neurons are elaborated, in an apparently hierarchical fashion,from those of their monocular, concentrically organized inputs to produce binocular interneurons with increasingly sophisticated requirements for stimulus orientation, movement and binocular disparity. Output neurons located in the superficial laminae of the Wulst are the most sophisticated of all, with absolute requirements for a combination of stimuli, which include binocular presentation at a particular horizontal binocular dis­parity, and with no response unless all of the stimulus conditions are satisfied simultaneously. Such neurons have the properties required for ‘global stereopsis,’ including a receptive field size many times larger than their optimal stimulus, which is more closely matched to the receptive fields of the simpler, disparity-selective interneurons. These marked similarities in functional organization between the avian and mammalian systems exist in spite of a number of structural differences which reflect their separate evolutionary origins. Discussion therefore includes the possibility that there may exist for nervous systems only a very small number of possible solutions, perhaps a unique one, to the problem of stereopsis.

Global stereopsis in human albinos

1989 ◽  
Vol 29 (10) ◽  
pp. 1359-1370 ◽  
Author(s):  
Patricia Apkarian ◽  
Dirk Reits
Keyword(s):  
Global Stereopsis

A New Random-Dot Stereo Illusion and its Application to the Anstis–Howard–Rogers Effect

Perception ◽  
1984 ◽  
Vol 13 (5) ◽  
pp. 547-553
Author(s):  
James Thomas Enright
Keyword(s):  
Geometrical Optics ◽  
Visual Noise ◽  
Visual Images ◽  
Dynamic Visual Noise ◽  
Residual Component ◽  
Different Depths ◽  
Global Stereopsis ◽  
Stable Surfaces ◽  
Local Depth

When the dynamic visual noise of an untuned television set is viewed with image defocusing (positive lenses) and with a narrow vertical obstruction partially blocking the pupil of one eye, the video ‘snow’ seems to separate into two stable surfaces at different depths, divided by a vertical discontinuity. The main features of this illusion can be quantitatively accounted for in terms of the optics of defocused images and the retinal disparities predicted from blur circles. A residual component of the illusion, however, which was perceived by a majority of subjects, cannot be readily explained by geometrical optics; it apparently reflects a more subtle aspect in the processing of visual images, corresponding to the Anstis–Howard–Rogers stereo-effect, in which local depth configurations can bias global stereopsis. Several novel aspects of that effect are described, based on use of this obstructed-pupil illusion as the evoking stimulus.

Global Stereopsis in Rhesus Monkeys

1975 ◽  
Vol 27 (1) ◽  
pp. 93-109 ◽  
Author(s):  
A. Cowey ◽  
A. M. Parkinson ◽  
L. Warnick
Keyword(s):  
Rhesus Monkeys ◽  
Polarized Light ◽  
Naive Animal ◽  
Depth Cues ◽  
Final Experiment ◽  
Random Dot Stereograms ◽  
Global Stereopsis ◽  
Incontrovertible Evidence

In three separate experiments an attempt was made to demonstrate global stereopsis in two rhesus monkeys by using random dot stereograms projected and viewed through polarizing filters. Although both animals learned a number of discriminations, control tests showed that both were perceiving non-depth cues such as monocular identification of minute pattern differences or brightness differences caused by reflections of polarized light. In a final experiment red/green anaglyph forms of the stereograms were viewed through red/green filters. Both monkeys, together with a third experimentally naive animal, showed incontrovertible evidence of prompt discrimination based on stereopsis. This paper makes a number of recommendations about the use of random dot stereograms to demonstrate global stereopsis in animals.

Depth Perception in Alzheimer's Disease

1996 ◽  
Vol 83 (3) ◽  
pp. 987-995 ◽  
Author(s):  
Mario F. Mendez ◽  
Monique M. Cherrier ◽  
Robert S. Meadows
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Depth Perception ◽  
Motion Parallax ◽  
Relative Size ◽  
Depth Cues ◽  
Visuospatial Deficits ◽  
Visuospatial Functions ◽  
Monocular Depth ◽  
Global Stereopsis

Abnormal depth perception contributes to visuospatial deficits in Alzheimer's disease. Disturbances in stereopsis, motion parallax, and the interpretation of static monocular depth cues may result from neuropathology in the visual cortex. We evaluated 15 patients with mild Alzheimer's disease and 15 controls matched for age, sex, and education on measures of local stereopsis (stereoscopic testing), global stereopsis (random dots), motion parallax (Howard-Dolman apparatus), and monocular depth perception by relative size, interposition, and perspective. Compared to controls, the patients were significantly impaired in over-all depth perception. This impairment was largely due to disturbances in local stereopsis and in the interpretation of depth from perspective, independent of other visuospatial functions. Patients with Alzheimer's disease have disturbed interpretation of monocular as well as binocular depth cues. This information could lead to optic interventions to improve their visual depth perception.

scholarly journals Transfer of Perceptual Learning From Local Stereopsis to Global Stereopsis in Adults With Amblyopia: A Preliminary Study

2021 ◽  
Vol 15 ◽  
Author(s):  
Adrien Chopin ◽  
Michael A. Silver ◽  
Yasha Sheynin ◽  
Jian Ding ◽  
Dennis Michael Levi
Keyword(s):  
Visual System ◽  
Transfer Of Learning ◽  
Image Features ◽  
Stereoscopic Vision ◽  
Stage Model ◽  
Single System ◽  
Matching Problem ◽  
Preliminary Study ◽  
Global Stereopsis ◽  
Global And Local

It has long been debated whether the analysis of global and local stereoscopic depth is performed by a single system or by separate systems. Global stereopsis requires the visual system to solve a complex binocular matching problem to obtain a coherent percept of depth. In contrast, local stereopsis requires only a simple matching of similar image features. In this preliminary study, we recruited five adults with amblyopia who lacked global stereopsis and trained them on a computerized local stereopsis depth task for an average of 12 h. Three out of five (60%) participants recovered fine global stereoscopic vision through training. Those who recovered global stereopsis reached a learning plateau more quickly on the local stereopsis task, and they tended to start the training with better initial local stereopsis performance, to improve more on local stereopsis with training, and to have less severe amblyopia. The transfer of learning from local stereopsis to global stereopsis is compatible with an interacting two-stage model.

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