What is visible across the visual field?

2020 ◽  
Author(s):  
Andrew Haun
Keyword(s):  
Visual Field ◽  
Spatial Scale ◽  
Contrast Sensitivity ◽  
Spatial Vision ◽  
Retinal Eccentricity ◽  
Natural Scenes ◽  
Edge Information ◽  
Detailed Model ◽  
Sensitivity Functions

In this paper I use a detailed model of human spatial vision to estimate the visibility of some perceptual properties across the visual field, including aspects of colorfulness, sharpness, and blurriness. The model is constructed to reproduce several patterns of human contrast sensitivity, functions of contrast, scale and retinal eccentricity. I apply the model to colorful, complex natural scenes, and estimate the degree to which color and edge information are present in the model’s representation of the scenes. I find that, aside from the intrinsic drift in the spatial scale of the representation, there are not large qualitative differences between foveal and peripheral representations of ‘colorfulness’ and ‘sharpness’.

scholarly journals What is visible across the visual field?

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Andrew M Haun
Keyword(s):  
Visual Field ◽  
Visual Perception ◽  
Peripheral Vision ◽  
Spatial Vision ◽  
Natural Scenes ◽  
Natural Scene ◽  
Foveal Vision ◽  
Edge Information ◽  
Detailed Model ◽  
Natural Scene Images

Abstract It is sometimes claimed that because the resolution and sensitivity of visual perception are better in the fovea than in the periphery, peripheral vision cannot support the same kinds of colour and sharpness percepts as foveal vision. The fact that a scene nevertheless seems colourful and sharp throughout the visual field then poses a puzzle. In this study, I use a detailed model of human spatial vision to estimate the visibility of certain properties of natural scenes, including aspects of colourfulness, sharpness, and blurriness, across the visual field. The model is constructed to reproduce basic aspects of human contrast and colour sensitivity over a range of retinal eccentricities. I apply the model to colourful, complex natural scene images, and estimate the degree to which colour and edge information are present in the model’s representation of the scenes. I find that, aside from the intrinsic drift in the spatial scale of the representation, there are not large qualitative differences between foveal and peripheral representations of ‘colourfulness’ and ‘sharpness’.

scholarly journals Gradiate: a radial sweep approach to measuring detailed contrast sensitivity functions from eye movements

2020 ◽  
Author(s):  
Scott William Joseph Mooney ◽  
Nazia Alam ◽  
N. Jeremy Hill ◽  
Glen T. Prusky
Keyword(s):  
Eye Movements ◽  
Aspect Ratio ◽  
Contrast Sensitivity ◽  
Spatial Vision ◽  
Shape Factors ◽  
High Agreement ◽  
Low Contrast ◽  
Sensitivity Functions ◽  
Logmar Acuity ◽  
Visual Health

The contrast sensitivity function (CSF) is an informative measure of visual health, but the practical difficulty of measuring it has impeded detailed analyses of its relationship to different visual disorders. Furthermore, most existing tasks cannot be used in populations with cognitive impairment. We analyzed detailed CSFs measured with a non-verbal procedure called “Gradiate”, which efficiently infers visibility from eye movements and manipulates stimulus appearance in real time. Sixty observers of varying age (38 with refractive error) were presented with moving stimuli. Stimulus spatial frequency and contrast advanced along fifteen radial sweeps through CSF space in response to stimulus-congruent eye movements. A point on the CSF was recorded when tracking ceased. Gradiate CSFs were reliable and in high agreement with independent low contrast acuity thresholds. Overall CSF variation was largely captured by two orthogonal factors (“radius” and “slope”), or two orthogonal shape factors when size was normalized (“aspect ratio” and “curvature”). CSF radius was highly predictive of LogMAR acuity, as were aspect ratio and curvature together, but only radius was predictive of observer age. Our findings suggest that Gradiate holds promise for assessing spatial vision in both verbal and non-verbal populations and indicate that variation between detailed CSFs can reveal useful information about visual health.

scholarly journals Sensitivity to visual motion in amblyopic macaque monkeys

2006 ◽  
Vol 23 (2) ◽  
pp. 247-256 ◽  
Author(s):  
LYNNE KIORPES ◽  
CHAO TANG ◽  
J. ANTHONY MOVSHON
Keyword(s):  
Contrast Sensitivity ◽  
Visual Motion ◽  
Spatial Scales ◽  
Spatial Vision ◽  
Motion Sensitivity ◽  
Sensitivity Functions ◽  
Wide Range ◽  
Spatial Contrast Sensitivity ◽  
Spatiotemporal Integration ◽  
Fellow Eyes

Amblyopia is usually considered to be a deficit in spatial vision. But there is evidence that amblyopes may also suffer specific deficits in motion sensitivity as opposed to losses that can be explained by the known deficits in spatial vision. We measured sensitivity to visual motion in random dot displays for strabismic and anisometropic amblyopic monkeys. We used a wide range of spatial and temporal offsets and compared the performance of the fellow and amblyopic eye for each monkey. The amblyopes were severely impaired at detecting motion at fine spatial and long temporal offsets, corresponding to fine spatial scale and slow speeds. This impairment was also evident for the untreated fellow eyes of strabismic but not anisometropic amblyopes. Motion sensitivity functions for amblyopic eyes were shifted toward large spatial scales for amblyopic compared to fellow eyes, to a degree that was correlated with the shift in scale of the spatial contrast sensitivity function. Amblyopic losses in motion sensitivity, however, were not correlated with losses in spatial contrast sensitivity. This, combined with the specific impairment for detecting long temporal offsets, reveals a deficit in spatiotemporal integration in amblyopia which cannot be explained by the lower spatial resolution of amblyopic vision.

scholarly journals Association of ocular blood flow and contrast sensitivity in normal tension glaucoma

2021 ◽  
Author(s):  
David Kuerten ◽  
Matthias Fuest ◽  
Peter Walter ◽  
Babac Mazinani ◽  
Niklas Plange
Keyword(s):  
Blood Flow ◽  
Visual Field ◽  
Contrast Sensitivity ◽  
Visual Field Defect ◽  
Prospective Trial ◽  
Normal Tension Glaucoma ◽  
Ocular Blood Flow ◽  
Retinal Blood Flow ◽  
Control Group ◽  
Field Defect

Abstract Purpose To investigate the relationship of ocular blood flow (via arteriovenous passage time, AVP) and contrast sensitivity (CS) in healthy as well as normal tension glaucoma (NTG) subjects. Design Mono-center comparative prospective trial Methods Twenty-five NTG patients without medication and 25 healthy test participants were recruited. AVP as a measure of retinal blood flow was recorded via fluorescein angiography after CS measurement using digital image analysis. Association of AVP and CS at 4 spatial frequencies (3, 6, 12, and 18 cycles per degree, cpd) was explored with correlation analysis. Results Significant differences regarding AVP, visual field defect, intraocular pressure, and CS measurement were recorded in-between the control group and NTG patients. In NTG patients, AVP was significantly correlated to CS at all investigated cpd (3 cpd: r =  − 0.432, p< 0.03; 6 cpd: r =  − 0.629, p< 0.0005; 12 cpd: r =  − 0.535, p< 0.005; and 18 cpd: r =  − 0.58, p< 0.001), whereas no significant correlations were found in the control group. Visual acuity was significantly correlated to CS at 6, 12, and 18 cpd in NTG patients (r =  − 0.68, p< 0.002; r =  − 0.54, p< .02, and r =  − 0.88, p< 0.0001 respectively), however not in healthy control patients. Age, visual field defect MD, and PSD were not significantly correlated to CS in in the NTG group. MD and PSD were significantly correlated to CS at 3 cpd in healthy eyes (r = 0.55, p< 0.02; r =  − 0.47, p< 0.03). Conclusion Retinal blood flow alterations show a relationship with contrast sensitivity loss in NTG patients. This might reflect a disease-related link between retinal blood flow and visual function. This association was not recorded in healthy volunteers.

scholarly journals Association of Vistech contrast sensitivity and visual field findings in glaucoma.

1991 ◽  
Vol 75 (9) ◽  
pp. 558-560 ◽  
Author(s):  
W E Sponsel ◽  
K L DePaul ◽  
J F Martone ◽  
M B Shields ◽  
A R Ollie ◽  
...  
Keyword(s):  
Visual Field ◽  
Contrast Sensitivity

scholarly journals Predicting individual contrast sensitivity functions from acuity and letter contrast sensitivity measurements

2016 ◽  
Vol 16 (15) ◽  
pp. 15 ◽  
Author(s):  
Steven M. Thurman ◽  
Pinakin Gunvant Davey ◽  
Kaydee Lynn McCray ◽  
Violeta Paronian ◽  
Aaron R. Seitz
Keyword(s):  
Contrast Sensitivity ◽  
Sensitivity Functions ◽  
Individual Contrast

scholarly journals Visual numerosity estimation is based on anisotropic representations of visual space

2021 ◽  
Author(s):  
Miao Li ◽  
Bert Reynvoet ◽  
Bilge Sayim
Keyword(s):  
Visual Field ◽  
Convex Hull ◽  
Visual Fields ◽  
Spatial Vision ◽  
Visual Space ◽  
Stimulus Features ◽  
Numerosity Estimation ◽  
Numerosity Perception ◽  
Average Eccentricity ◽  
Shed Light

Humans can estimate the number of visually displayed items without counting. This capacity of numerosity perception has often been attributed to a dedicated system to estimate numerosity, or alternatively to the exploitation of various stimulus features, such as density, convex hull, the size of items and occupancy area. The distribution of the presented items is usually not varied with eccentricity in the visual field. However, our visual fields are highly asymmetric, and to date, it is unclear how inhomogeneities of the visual field impact numerosity perception. Besides eccentricity, a pronounced asymmetry is the radial-tangential anisotropy. For example, in crowding, radially placed flankers interfere more strongly with target perception than tangentially placed flankers. Similarly, in redundancy masking, the number of perceived items in repeating patterns is reduced when the items are arranged radially but not when they are arranged tangentially. Here, we investigated whether numerosity perception is subject to the radial-tangential anisotropy of spatial vision to shed light on the underlying topology of numerosity perception. Observers were presented with varying numbers of discs and asked to report the perceived number. There were two conditions. Discs were predominantly arranged radially in the “radial” condition and tangentially in the “tangential” condition. Additionally, the spacing between discs was scaled with eccentricity. Physical properties, such as average eccentricity, average spacing, convex hull, and density were kept as similar as possible in the two conditions. Radial arrangements were expected to yield underestimation compared to tangential arrangements. Consistent with the hypothesis, numerosity estimates in the radial condition were lower compared to the tangential condition. Magnitudes of radial alignment (as well as predicted crowding strength) correlated with the observed numerosity estimates. Our results demonstrate a robust radial-tangential anisotropy, suggesting that the topology of spatial vision determines numerosity estimation. We suggest that asymmetries of spatial vision should be taken into account when investigating numerosity estimation.

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