scholarly journals Treated amblyopes remain deficient in spatial vision: A contrast sensitivity and external noise study

2007 ◽  
Vol 47 (1) ◽  
pp. 22-34 ◽  
Author(s):  
Changbing Huang ◽  
Liming Tao ◽  
Yifeng Zhou ◽  
Zhong-Lin Lu
Keyword(s):  
Contrast Sensitivity ◽  
Spatial Vision ◽  
External Noise

Spatial vision in strabismic cats

1983 ◽  
Vol 50 (1) ◽  
pp. 287-296 ◽  
Author(s):  
K. Holopigian ◽  
R. Blake
Keyword(s):  
Contrast Sensitivity ◽  
Preceding Paper ◽  
Spatial Vision ◽  
Performance Difference ◽  
Single Class ◽  
Convergent Strabismus ◽  
Contrast Thresholds

Contrast thresholds for detection of stationary and flickering gratings were measured behaviorally for each eye of cats raised with induced convergent strabismus. The performance of the deviating eye was inferior to that of the nondeviating eye when test patterns were stationary. Flicker served to reduce the performance difference between the eyes in two cats but not in a third. These results suggest that strabismus amblyopia may not result from deficits within a single class of neurons. In all strabismic cats the contrast sensitivity of the nondeviating eye was significantly reduced relative to normal cats. These behavioral findings, including the deficits found bilaterally, correspond very well with results from cortical recordings from these and other strabismic cats presented in the preceding paper (7).

Bandwidth of the Contrast Sensitivity Function as an Index of Spatial Vision with Application to Refraction

1990 ◽  
Vol 67 (4) ◽  
pp. 260-267 ◽  
Author(s):  
BAI-CHUAN JIANG ◽  
CHARLES T. SCIALFA ◽  
RICHARD A. TYRRELL ◽  
PHILIP M. GARVEY ◽  
HERSCHEL W. LEIBOWITZ
Keyword(s):  
Contrast Sensitivity ◽  
Spatial Vision ◽  
Sensitivity Function ◽  
Contrast Sensitivity Function

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.

Spatial Vision and Aging. I: Contrast Sensitivity

1980 ◽  
Vol 35 (5) ◽  
pp. 692-699 ◽  
Author(s):  
R. Sekuler ◽  
L. P. Hutman
Keyword(s):  
Contrast Sensitivity ◽  
Spatial Vision

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 External noise paradigms, contrast sensitivity and aging

2013 ◽  
Vol 13 (9) ◽  
pp. 274-274
Author(s):  
J. Renaud ◽  
R. Allard ◽  
S. Molinatti ◽  
J. Faubert
Keyword(s):  
Contrast Sensitivity ◽  
External Noise

scholarly journals Ocellar spatial vision in Myrmecia ants

2021 ◽  
Author(s):  
Bhavana Penmetcha ◽  
Yuri Ogawa ◽  
Laura A. Ryan ◽  
Nathan S. Hart ◽  
Ajay Narendra
Keyword(s):  
Apis Mellifera ◽  
Contrast Sensitivity ◽  
Spatial Vision ◽  
Flight Time ◽  
Resolving Power ◽  
Compound Eyes ◽  
Pattern Electroretinography ◽  
Visual Systems ◽  
Visual Properties ◽  
European Honeybee

In addition to the compound eyes, insects possess simple eyes known as ocelli. Input from the ocelli modulates optomotor responses, flight-time initiation, and phototactic responses—behaviours that are mediated predominantly by the compound eyes. In this study, using pattern electroretinography (pERG), we investigated the contribution of the compound eyes to ocellar spatial vision in the diurnal Australian bull ant Myrmecia tarsata by measuring the contrast sensitivity and spatial resolving power of the ocellar second-order neurons under various occlusion conditions. Furthermore, in four species of Myrmecia ants active at different times of the day, and in European honeybee Apis mellifera, we characterized the ocellar visual properties when both visual systems were available. Among the ants, we found that the time of activity had no significant effect on ocellar spatial vision. Comparing day-active ants and the honeybee we did not find any significant effect of locomotion on ocellar spatial vision. In M. tarsata, when the compound eyes were occluded, the amplitude of the pERG signal from the ocelli reduced by three times compared to conditions when the compound eyes were available. The signals from the compound eyes maintained the maximum contrast sensitivity of the ocelli as 13 (7.7%), and the spatial resolving power as 0.29 cpd. We conclude that ocellar spatial vison improves significantly with input from the compound eyes, with a noticeably larger improvement in contrast sensitivity than in spatial resolving power.

Spatial vision of the cat: Variation with eccentricity

1991 ◽  
Vol 6 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Tatiana Pasternak ◽  
Kris Horn
Keyword(s):  
Spatial Frequency ◽  
Contrast Sensitivity ◽  
High Spatial Frequency ◽  
Spatial Vision ◽  
Target Size ◽  
Horizontal Meridian ◽  
Resolution Limit ◽  
Vertical Meridian ◽  
Area Centralis ◽  
Grating Acuity

AbstractWe examined the grating acuity and contrast sensitivity of cats whose eye position was monitored with a scleral search-coil technique. During each trial, the cat was required to maintain fixation on a laser spot and respond to the presence or the absence of a grating by pressing a right or left pedal. With this procedure, acuity was measured along the horizontal and vertical meridian over a range of eccentricities in the nasal, temporal, superior, and inferior retina. In addition, contrast sensitivity for stationary and drifting gratings was measured for the temporal retina along the horizontal meridian. Acuity in area centralis reached about 3.5 cycle\deg and declined by 0.5 octaves at 4 deg and by about 1.3 octaves at 16-deg eccentricity in the nasal retina. The acuity was higher in the nasal than temporal retina. At all eccentricities, spatial resolution exceeded the resolution limit derived from Y (alpha)-cell properties. Contrast sensitivity also decreased as the eccentricity increased when the target size was held constant. The slope of sensitivity-eccentricity function was relatively shallow for a low spatial frequency (0.30 cycle\deg) with sensitivity decreasing by a factor of 1.5–2 at 8-deg eccentricity. The slope of the sensitivity falloff for high spatial-frequency gratings (1.2 cycle\deg) was steeper, with a 5–10-fold difference in sensitivity between 0 and 8 deg. By varying the target size, we determined that the summation area in the cat is about a factor of 3 smaller in area centralis than a 16-deg eccentricity. When the size of the centrally and peripherally viewed targets was scaled relative to visual acuity, the sensitivity was constant across the visual field.

scholarly journals Development of sensitivity to visual motion in macaque monkeys

2004 ◽  
Vol 21 (6) ◽  
pp. 851-859 ◽  
Author(s):  
LYNNE KIORPES ◽  
J. ANTHONY MOVSHON
Keyword(s):  
Contrast Sensitivity ◽  
Visual Motion ◽  
Spatial Vision ◽  
Macaca Nemestrina ◽  
First Year ◽  
Motion Sensitivity ◽  
Macaque Monkeys ◽  
Spatial Frequencies ◽  
Visual Areas ◽  
The Relationship

The development of spatial vision is relatively well documented in human and nonhuman primates. However, little is known about the development of sensitivity to motion. We measured the development of sensitivity to direction of motion, and the relationship between motion and contrast sensitivity in macaque monkeys as a function of age. Monkeys (Macaca nemestrina, aged between 10 days and 3 years) discriminated direction of motion in random-dot kinematograms. The youngest monkeys showed directionally selective orienting and the ability to integrate motion signals at large dot displacements and fast speeds. With age, coherence sensitivity improved for all spatial and temporal dot displacements tested. The temporal interval between the dots was far less important than the spatial offset in determining the animals' performance at all but the youngest ages. Motion sensitivity improved well beyond the end of the first postnatal year, when mid-spatial-frequency contrast sensitivity reached asymptote, and continued for at least 3 years. Sensitivity to contrast at high spatial frequencies also continued to develop beyond the end of the first year. We conclude that the development of motion sensitivity depends on mechanisms beyond the low-level filters presumed to limit acuity and contrast sensitivity, and most likely reflects the function of extrastriate visual areas.

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