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.

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 The marine gastropod Conomurex luhuanus (Strombidae) has high-resolution spatial vision and eyes with complex retinas

2021 ◽  
Author(s):  
Alison R Irwin ◽  
Suzanne T Williams ◽  
Daniel I Speiser ◽  
Nicholas W Roberts
Keyword(s):  
Electron Microscopy ◽  
Contrast Sensitivity ◽  
Spatial Resolution ◽  
Imaging Techniques ◽  
Visual Stimuli ◽  
Angular Size ◽  
Spatial Vision ◽  
Cell Types ◽  
Low Contrast ◽  
Snail Family

All species within the conch snail family Strombidae possess large camera-type eyes that are surprisingly well-developed compared to those found in most other gastropods. Although these eyes are known to be structurally complex, very little research on their visual function has been conducted. Here, we use isoluminant expanding visual stimuli to measure the spatial resolution and contrast sensitivity of a strombid, Conomurex luhuanus. Using these stimuli, we show that this species responds to objects as small as 1.06° in its visual field. We also show that C. luhuanus responds to Michelson contrasts of 0.07, a low contrast sensitivity between object and background. The defensive withdrawal response elicited by visual stimuli of such small angular size and low contrast suggests that conch snails may use spatial vision for the early detection of potential predators. We support these findings with morphological estimations of spatial resolution of 1.04 ± 0.14°. These anatomical data therefore agree with the behavioural measures and highlight the benefits of integrating morphological and behavioural approaches in animal vision studies. Furthermore, using contemporary imaging techniques including serial block-face scanning electron microscopy (SBF-SEM), in conjunction with transmission electron microscopy (TEM), we found that C. luhuanus have more complex retinas, in terms of cell type diversity, than previous studies of the group have discovered using TEM alone. We found the C. luhuanus retina is comprised of six cell types, including a newly identified ganglion cell and accessory photoreceptor, rather than the previously described four cell types.

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

2020 ◽  
Vol 20 (13) ◽  
pp. 17
Author(s):  
Scott W. J. Mooney ◽  
Nazia M. Alam ◽  
N. Jeremy Hill ◽  
Glen T. Prusky
Keyword(s):  
Eye Movements ◽  
Contrast Sensitivity ◽  
Sensitivity Functions

Pediatric Cataract Surgery: Comparison between Ages at Surgery and Contrast Sensitivity Outcomes

2019 ◽  
Vol 43 (1) ◽  
pp. 50
Author(s):  
Aquirina Caesari Putri ◽  
Rozalina Loebis
Keyword(s):  
Visual Acuity ◽  
Cataract Surgery ◽  
Contrast Sensitivity ◽  
Cataract Extraction ◽  
Significant Negative Correlation ◽  
Natural World ◽  
P Value ◽  
Pediatric Cataract ◽  
Low Contrast ◽  
Significant Difference

Background: Pediatric cataracts are major causes of children’s blindness. Surgery has proven to be beneficial in terms of visual function prognosis. Contrast sensitivity evaluation after surgery is as important as visual acuity considering that natural world consists of various objects in low-to-medium contrasts. The purpose of this study is to analyze the difference of contrast sensitivity outcomes based on ages at surgery. Method: Retrospective data of children with pediatric developmental cataract from July 2013 to November 2015 were collected. All children who underwent cataract surgery at 60-months-old or less were randomized into two groups, ≤24 months and >24-to-60 months. Contrast sensitivity was then examined with preferential-looking method using Hiding Heidi low-contrast test face chart. The main outcome measures were contrast sensitivity of both groups. Age-at-evaluation, cataract onset, duration of follow-up, duration of deprivation and visual acuity were also noted. Result: Of 14 children (23 eyes), 11 eyes (47,8%) were in ≤24 months group, 12eyes (52,2%) were in >24-to-60 months group. All eyes underwent cataract extraction and similar type of intraocular lens implantation. Mean age-at-surgery was 28,2 months±16,8 (SD). Mean contrast sensitivity for each group was 47,50 %±42,29 and 18,33%±27,38, respectively, with p-value 0,031. Further analysis of Spearman’s correlation test demonstrated significant negative correlation (rs = -0,559; p = 0,006) between the two groups. Conclusion: There was statistically significant difference in contrast sensitivity between those who underwent surgery at ≤24 months and >24-to-60 months. Children who underwent surgery at older ages tend to have better contrast sensitivity afterwards.

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 Genetic disruption of the On visual pathway affects cortical orientation selectivity and contrast sensitivity in mice

2014 ◽  
Vol 111 (11) ◽  
pp. 2276-2286 ◽  
Author(s):  
Rashmi Sarnaik ◽  
Hui Chen ◽  
Xiaorong Liu ◽  
Jianhua Cang
Keyword(s):  
Contrast Sensitivity ◽  
Visual Pathway ◽  
Response Variability ◽  
Stimulus Contrast ◽  
Wild Type ◽  
Low Contrast ◽  
Pharmacological Blockade ◽  
Single Unit Recordings ◽  
On And Off Pathways

The retina signals stimulus contrast via parallel On and Off pathways and sends the information to higher visual centers. Here we study the role of the On pathway using mice that have null mutations in the On-specific GRM6 receptor in the retina (Pinto LH, Vitaterna MH, Shimomura K, Siepka SM, Balannik V, McDearmon EL, Omura C, Lumayag S, Invergo BM, Brandon M, Glawe B, Cantrell DR, Donald R, Inayat S, Olvera MA, Vessey KA, Kirstan A, McCall MA, Maddox D, Morgans CW, Young B, Pletcher MT, Mullins RF, Troy JB, Takahashi JS. Vis Neurosci 24: 111–123, 2007; Maddox DM, Vessey KA, Yarbrough GL, Invergo BM, Cantrell DR, Inayat S, Balannik V, Hicks WL, Hawes NL, Byers S, Smith RS, Hurd R, Howell D, Gregg RG, Chang B, Naggert JK, Troy JB, Pinto LH, Nishina PM, McCall MA. J Physiol 586: 4409–4424, 2008). In these “nob” mice, single unit recordings in the primary visual cortex (V1) reveal degraded selectivity for orientations due to an increased response at nonpreferred orientations. Contrast sensitivity in the nob mice is reduced with severe deficits at low contrast, consistent with the phenotype of night blindness in human patients with mutations in Grm6. These cortical deficits can be largely explained by reduced input drive and increased response variability seen in nob V1. Interestingly, increased variability is also observed in the superior colliculus of these mice but does not affect its tuning properties. Further, the increased response variability in the nob mice is traced to the retina, a result phenocopied by acute pharmacological blockade of the On pathway in wild-type retina. Together, our results suggest that the On and Off pathways normally interact to increase response reliability in the retina, which in turn propagates to various central visual targets and affects their functional properties.

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