Peripheral and Central Factors Limiting Spatial Contrast Sensitivity in Infant Macaque Monkeys

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 207-207
Author(s):  
L Kiorpes ◽  
J A Movshon
Keyword(s):  
Contrast Sensitivity ◽  
Developmental Process ◽  
Signal To Noise Ratio ◽  
Intrinsic Noise ◽  
Visual Sensitivity ◽  
Macaca Nemestrina ◽  
Contrast Threshold ◽  
Spatial Frequencies ◽  
Two Parameters ◽  
Central Factors

To evaluate the contribution of peripheral and central factors to the development of visual sensitivity, we measured contrast thresholds for sinusoidal gratings (0.5 – 4.2 cycles deg−1), presented alone and in the presence of added dynamic visual noise, in infant monkeys. We wished to use the changes in contrast threshold during development, in the presence and absence of masking noise, to establish what mechanisms might be responsible for this developmental process. We tested Macaca nemestrina monkeys, aged 1 – 18 months, on a spatial contrast detection task, and analysed the masking functions to calculate two parameters: equivalent intrinsic noise ( Neq, the noise contrast at which squared contrast threshold was doubled), and signal-to-noise ratio ( Rsn, the asymptotic ratio of threshold to noise contrast at high noise contrasts). We hypothesise, following Pelli, that Neq measures a peripheral limit while Rsn measures a central one. Our data suggest that intrinsic noise is high in infants and falls with contrast threshold during development, thus supporting the hypothesis that peripheral factors set an important limit on the development of contrast sensitivity. However, the relationship between Neq and contrast threshold varied somewhat with spatial frequency. At low spatial frequencies, contrast threshold was well specified by knowledge of Neq, whereas at higher spatial frequencies, changes in Rsn had a relatively greater weight. We conclude that peripheral factors set an important limit on the development of sensitivity at all spatial frequencies; central factors are needed to account for some aspects of development at higher frequencies.

Comparison of contrast sensitivity in macaque monkeys and humans

2019 ◽  
Vol 36 ◽  
Author(s):  
William H. Ridder ◽  
Kai Ming Zhang ◽  
Apoorva Karsolia ◽  
Michael Engles ◽  
James Burke
Keyword(s):  
Contrast Sensitivity ◽  
Macaca Mulatta ◽  
Macaca Fascicularis ◽  
Area Under The Curve ◽  
Macaca Nemestrina ◽  
Published Data ◽  
Sensitivity Functions ◽  
Spatial Frequencies ◽  
Double Exponential ◽  
Normal Humans

AbstractContrast sensitivity functions reveal information about a subject’s overall visual ability and have been investigated in several species of nonhuman primates (NHPs) with experimentally induced amblyopia and glaucoma. However, there are no published studies comparing contrast sensitivity functions across these species of normal NHPs. The purpose of this investigation was to compare contrast sensitivity across these primates to determine whether they are similar. Ten normal humans and eight normal NHPs (Macaca fascicularis) took part in this project. Previously published data from Macaca mulatta and Macaca nemestrina were also compared. Threshold was operationally defined as two misses in a row for a descending method of limits. A similar paradigm was used for the humans except that the descending method of limits was combined with a spatial, two-alternative forced choice (2-AFC) technique. The contrast sensitivity functions were fit with a double exponential function. The averaged peak contrast sensitivity, peak spatial frequency, acuity, and area under the curve for the humans were 268.9, 3.40 cpd, 27.3 cpd, and 2345.4 and for the Macaca fascicularis were 99.2, 3.93 cpd, 26.1 cpd, and 980.9. A two-sample t-test indicated that the peak contrast sensitivities (P = 0.001) and areas under the curve (P = 0.010) were significantly different. The peak spatial frequencies (P = 0.150) and the extrapolated visual acuities (P = 0.763) were not different. The contrast sensitivities for the Macaca fascicularis, Macaca mulatta, and Macaca nemestrina were qualitatively and quantitatively similar. The contrast sensitivity functions for the NHPs had lower peak contrast sensitivities and areas under the curve than the humans. Even though different methods have been used to measure contrast sensitivity in different species of NHP, the functions are similar. The contrast sensitivity differences and similarities between humans and NHPs need to be considered when using NHPs to study human disease.

scholarly journals Neuronal basis of perceptual learning in striate cortex

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Zhen Ren ◽  
Jiawei Zhou ◽  
Zhimo Yao ◽  
Zhengchun Wang ◽  
Nini Yuan ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Perceptual Learning ◽  
Contrast Sensitivity ◽  
Striate Cortex ◽  
Signal To Noise Ratio ◽  
High Spatial Frequency ◽  
Sensitivity Training ◽  
Spatial Frequencies ◽  
Cortex Area ◽  
Adult Cats

Abstract It is well known that, in humans, contrast sensitivity training at high spatial frequency (SF) not only leads to contrast sensitivity improvement, but also results in an improvement in visual acuity as assessed with gratings (direct effect) or letters (transfer effect). However, the underlying neural mechanisms of this high spatial frequency training improvement remain to be elucidated. In the present study, we examined four properties of neurons in primary visual cortex (area 17) of adult cats that exhibited significantly improved acuity after contrast sensitivity training with a high spatial frequency grating and those of untrained control cats. We found no difference in neuronal contrast sensitivity or tuning width (Width) between the trained and untrained cats. However, the trained cats showed a displacement of the cells’ optimal spatial frequency (OSF) to higher spatial frequencies as well as a larger neuronal signal-to-noise ratio (SNR). Furthermore, both the neuronal differences in OSF and SNR were significantly correlated with the improvement of acuity measured behaviorally. These results suggest that striate neurons might mediate the perceptual learning-induced improvement for high spatial frequency stimuli by an alteration in their spatial frequency representation and by an increased SNR.

An Assessment of Decision-Making as a Possible Factor in the Age-Related Loss of Contrast Sensitivity

Perception ◽  
1986 ◽  
Vol 15 (5) ◽  
pp. 541-552 ◽  
Author(s):  
James D Morrison ◽  
James Reilly
Keyword(s):  
Decision Making ◽  
Contrast Sensitivity ◽  
Contrast Threshold ◽  
Sinusoidal Grating ◽  
Hit Rate ◽  
Grating Pattern ◽  
Age Related ◽  
Spatial Frequencies ◽  
Young Subjects ◽  
Contrast Thresholds

The possibility that changes in decision-making may contribute to the age-related decline in contrast sensitivity has been investigated in nineteen young subjects (ages 21–38 years) and twenty-seven old subjects (ages 55–92 years). A signal detection paradigm was employed in which the detection of stationary sinusoidal grating patterns was measured at 3 and 15 cycles deg−1 for a range of contrasts which were psychophysically equivalent for each subject. A decline in contrast sensitivity with age at the spatial frequencies studied was confirmed for contrast thresholds obtained both by the ascending method and from the 50% hit rate for detection of the grating pattern. The criterion adopted for decision-making, expressed as both β and percentage bias, did not change significantly between young and old subjects at 15 cycles deg−1. At 3 cycles deg−1, criterion β did not change significantly at x0.8, x1.0, or x1.2 contrast threshold, but at contrast giving 50% hit rate there was a significant increase with age. The percentage bias increased significantly at contrast threshold but not at 50% hit rate. It is inferred from the results that the loss of contrast sensitivity was not accountable in terms of the adoption of a more conservative criterion by older subjects. Hence visual loss in ageing is attributed to changes within the visual pathway rather than within higher decision-making centres.

scholarly journals Contrast sensitivity, V1 neural activity, and natural vision

2017 ◽  
Vol 117 (2) ◽  
pp. 492-508 ◽  
Author(s):  
James E. Niemeyer ◽  
Michael A. Paradiso
Keyword(s):  
Eye Movements ◽  
Contrast Sensitivity ◽  
Visual Processing ◽  
Brain Area ◽  
Saccadic Eye Movements ◽  
Visual Sensitivity ◽  
Natural Image ◽  
Spatial Frequencies ◽  
Natural Vision ◽  
Common Laboratory

Contrast sensitivity is fundamental to natural visual processing and an important tool for characterizing both visual function and clinical disorders. We simultaneously measured contrast sensitivity and neural contrast response functions and compared measurements in common laboratory conditions with naturalistic conditions. In typical experiments, a subject holds fixation and a stimulus is flashed on, whereas in natural vision, saccades bring stimuli into view. Motivated by our previous V1 findings, we tested the hypothesis that perceptual contrast sensitivity is lower in natural vision and that this effect is associated with corresponding changes in V1 activity. We found that contrast sensitivity and V1 activity are correlated and that the relationship is similar in laboratory and naturalistic paradigms. However, in the more natural situation, contrast sensitivity is reduced up to 25% compared with that in a standard fixation paradigm, particularly at lower spatial frequencies, and this effect correlates with significant reductions in V1 responses. Our data suggest that these reductions in natural vision result from fast adaptation on one fixation that lowers the response on a subsequent fixation. This is the first demonstration of rapid, natural-image adaptation that carries across saccades, a process that appears to constantly influence visual sensitivity in natural vision. NEW & NOTEWORTHY Visual sensitivity and activity in brain area V1 were studied in a paradigm that included saccadic eye movements and natural visual input. V1 responses and contrast sensitivity were significantly reduced compared with results in common laboratory paradigms. The parallel neural and perceptual effects of eye movements and stimulus complexity appear to be due to a form of rapid adaptation that carries across saccades.

Acuity and contrast sensitivity of the bluegill sunfish and how they change during optic nerve regeneration

2007 ◽  
Vol 24 (3) ◽  
pp. 319-331 ◽  
Author(s):  
D.P.M. NORTHMORE ◽  
D.-J. OH ◽  
M.A. CELENZA
Keyword(s):  
Optic Nerve ◽  
Spatial Frequency ◽  
Contrast Sensitivity ◽  
Cutoff Frequency ◽  
Lepomis Macrochirus ◽  
High Spatial Frequency ◽  
Contrast Threshold ◽  
Bluegill Sunfish ◽  
Sensitivity Functions ◽  
Spatial Frequencies

Spatial vision was studied in the bluegill sunfish, Lepomis macrochirus (9.5–14 cm standard length) to assess the limitations imposed by the optics of the eye, the retinal receptor spacing and the retinotectal projection during regeneration. Examination of images formed by the dioptric elements of the eye showed that spatial frequencies up to 29 c/° could be imaged on the retina. Cone spacing was measured in the retina of fresh, intact eyes. The spacing of rows of double cones predicted 3.4 c/° as the cutoff spatial frequency; the spacing between rows of single and double cones predicted 6.7 c/°. Contrast sensitivity functions were obtained psychophysically in normals and fish with one regenerating optic nerve. Fish were trained to orient to gratings (mean luminance = 25 cd/m2) presented to either eye. In normals, contrast sensitivity functions were similar in shape and bandwidth to those of other species, peaking at 0.4 c/° with a minimum contrast threshold of 0.03 and a cutoff at about 5 c/°, which was within the range predicted by cone spacing. Given that the optical cutoff frequency exceeds that predicted by cone spacing, it is possible that gratings could be detected by aliasing with the bluegill's regular cone mosaic. However, tests with high contrast gratings up to 15 c/° found no evidence of such detection. After crushing one optic nerve in three trained sunfish, recovery of visual avoidance, dorsal light reflex and orienting to gratings, were monitored over 315 days. At 64–69 days postcrush, responses to gratings reappeared, and within 2–5 days contrast sensitivity at low (0.15 c/°) and medium (1.0 c/°) spatial frequencies had returned to normal. At a high spatial frequency (2.93 c/°) recovery was much slower, and complete only in one fish.

scholarly journals Selective modulation of visual sensitivity during fixation

2018 ◽  
Vol 119 (6) ◽  
pp. 2059-2067 ◽  
Author(s):  
Chris Scholes ◽  
Paul V. McGraw ◽  
Neil W. Roach
Keyword(s):  
Eye Movements ◽  
Spatial Frequency ◽  
Contrast Sensitivity ◽  
Eye Movement ◽  
Visual Processing ◽  
Spatial Scales ◽  
Gain Control ◽  
Visual Sensitivity ◽  
Ocular Movements ◽  
Spatial Frequencies

During periods of steady fixation, we make small-amplitude ocular movements, termed microsaccades, at a rate of 1–2 every second. Early studies provided evidence that visual sensitivity is reduced during microsaccades—akin to the well-established suppression associated with larger saccades. However, the results of more recent work suggest that microsaccades may alter retinal input in a manner that enhances visual sensitivity to some stimuli. Here we parametrically varied the spatial frequency of a stimulus during a detection task and tracked contrast sensitivity as a function of time relative to microsaccades. Our data reveal two distinct modulations of sensitivity: suppression during the eye movement itself and facilitation after the eye has stopped moving. The magnitude of suppression and facilitation of visual sensitivity is related to the spatial content of the stimulus: suppression is greatest for low spatial frequencies, while sensitivity is enhanced most for stimuli of 1–2 cycles/°, spatial frequencies at which we are already most sensitive in the absence of eye movements. We present a model in which the tuning of suppression and facilitation is explained by delayed lateral inhibition between spatial frequency channels. Our data show that eye movements actively modulate visual sensitivity even during fixation: the detectability of images at different spatial scales can be increased or decreased depending on when the image occurs relative to a microsaccade. NEW & NOTEWORTHY Given the frequency with which we make microsaccades during periods of fixation, it is vital that we understand how they affect visual processing. We demonstrate two selective modulations of contrast sensitivity that are time-locked to the occurrence of a microsaccade: suppression of low spatial frequencies during each eye movement and enhancement of higher spatial frequencies after the eye has stopped moving. These complementary changes may arise naturally because of sluggish gain control between spatial channels.

scholarly journals Binocular Summation Is Intact in Intermittent Exotropia After Surgery

2021 ◽  
Vol 8 ◽  
Author(s):  
Meiping Xu ◽  
Yiya Chen ◽  
Yiyi Peng ◽  
Zhifen He ◽  
Jun Jiang ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Contrast Sensitivity ◽  
Visual Information ◽  
Threshold Level ◽  
Contrast Threshold ◽  
Binocular Summation ◽  
Intermittent Exotropia ◽  
Probability Summation ◽  
Spatial Frequencies ◽  
Significant Difference

Purpose: To determine binocular summation of surgically treated intermittent exotropia (IXT) patients by measuring the contrast threshold.Methods: We recruited 38 surgically treated IXT patients aged 8–24 years and 20 age-matched healthy controls. All participants had normal or corrected-to-normal visual acuity (Snellen ≥ 20/20) in both eyes. The IXT patients had undergone the surgery at least a year prior to the study. Twenty-one of them obtained good alignment and 17 experienced a recurrence of exotropia. We measured the observers' monocular and binocular contrast sensitivities (CS) at six spatial frequencies (1.5, 3, 6, 12, 18, 24 cycles/degree) as an index of visual information processing at the threshold level. Binocular summation was evaluated against a baseline model of simple probability summation based on the CS at each spatial frequency and the area under the log contrast sensitivity function (AULCSF).Results: The exo-deviation of IXTs with good alignment was −6.38 ± 3.61 prism diopters (pd) at 33 cm and −5.14 ± 4.07 pd at 5 m. For the patients with recurrence, it was −23.47 ± 5.53 pd and −21.12 ± 4.28 pd, respectively. There was no significant difference in the binocular summation ratio (BSR) between the surgically treated IXT patients, including those with good alignment and recurrence, and normal controls at each spatial frequency [F(2,55) = 0.416, P = 0.662] and AULCSF [F(2,55) = 0.469, P = 0.628]. In addition, the BSR was not associated with stereopsis (r = −0.151, P = 0.365).Conclusion: Our findings of normal contrast sensitivity binocular summation ratio in IXT after surgical treatment suggest that the ability of the visual cortex in processing binocular information is intact at the contrast threshold level.

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.

scholarly journals Predictors of macular pigment and contrast threshold in Spanish healthy normolipemic subjects (45–65 years) with habitual food intake

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251324
Author(s):  
Begoña Olmedilla-Alonso ◽  
Elena Rodríguez-Rodríguez ◽  
Beatriz Beltrán-de-Miguel ◽  
Rocío Estévez-Santiago ◽  
Milagros Sánchez-Prieto
Keyword(s):  
Dietary Intake ◽  
Contrast Sensitivity ◽  
Vegetable Consumption ◽  
Hdl Cholesterol ◽  
Visual Outcome ◽  
Macular Pigment ◽  
Contrast Threshold ◽  
Serum Concentrations ◽  
Spatial Frequencies ◽  
Lower Ratio

Introduction The dietary carotenoids lutein (L) and zeaxanthin (Z) are transported in the bloodstream by lipoproteins, sequestered by adipose tissue, and eventually captured in the retina where they constitute macular pigment. There are no L&Z dietary intake recommendations nor desired blood/tissue concentrations for the Spanish general population. Our aim was to assess the correlation of L&Z habitual dietary intake (excluding food supplements), resulting serum concentrations and lipid profile with macular pigment optical density (MPOD) as well as the contrast sensitivity (CT), as visual outcome in normolipemic subjects (n = 101) aged 45–65. Methods MPOD was measured by heterochromatic flicker photometry, serum L&Z by HPLC, the dietary intake by a 3-day food records and CT using the CGT-1000-Contrast-Glaretester at six stimulus sizes, with and without glare. Results Lutein and zeaxanthin concentrations (median) in serum: 0.361 and 0.078 μmol/L, in dietary intake: 1.1 mg L+Z/day. MPOD: 0.34du. L+Z intake correlates with their serum concentrations (rho = 0.333, p = 0.001), which in turn correlates with MPOD (rho = 0.229, p = 0.000) and with fruit and vegetable consumption (rho = 0.202, p = 0.001), but not with lutein+zeaxanthin dietary intake. MPOD correlated with CT, with and without glare (rho ranges: -0.135, 0.160 and -0.121, –0.205, respectively). MPOD predictors: serum L+Z, L+Z/HDL-cholesterol (β-coeficient: -0.91±0.2, 95%CI: -1.3,-0.5) and HDL-cholesterol (R2 = 15.9%). CT predictors: MPOD, mainly at medium and smaller visual angles (corresponding to spatial frequencies for which sensitivity declines with age) and gender (β-coefficients ranges: -0.95,-0.39 and -0.13,-0.39, respectively). Conclusion A higher MPOD is associated with a lower ratio of L+Z/HDL-cholesterol and with a lower CT (higher contrast sensitivity). The HDL-cholesterol would also act indirectly on the CT improving the visual function.

scholarly journals Aspheric Intraocular Lenses Implantation for Cataract Patients with Extreme Myopia

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Yanwen Fang ◽  
Yi Lu ◽  
Aizhu Miao ◽  
Yi Luo
Keyword(s):  
Contrast Sensitivity ◽  
Visual Quality ◽  
Intraocular Lenses ◽  
Wavefront Aberrations ◽  
Spatial Frequencies ◽  
Aspheric Iol ◽  
Significant Difference ◽  
Composite Scores ◽  
Cataract Patients

Objective. To evaluate the postoperative visual quality of cataract patients with extreme myopia after implantation of aspheric intraocular lenses (IOLs). Methods. Thirty-three eyes were enrolled in this prospectivestudy. Eighteen eyes with an axial length longer than 28 mm were included in the extreme myopia group, and the other 15 eyes were included in the nonextreme myopia group. Phacoemulsification and aspheric IOL implantation were performed. Six months after cataract surgery, best-corrected visual acuity (BCVA), contrast sensitivity, and wavefront aberrations were measured, and subjective visual quality was assessed. Results. The BCVA improved significantly after surgery for both groups, and patients in the nonextreme myopia group achieved better postoperative BCVA due to better retinal status of the eyes. The evaluation of contrast sensitivity without glare was the same in both groups, whereas patients in the nonextreme myopia group performed better at intermediate spatial frequencies under glare conditions. The two groups did not show a significant difference in high-order aberrations. With regard to subjective visual quality, the composite scores of both groups did not differ significantly. Conclusions. Aspheric IOLs provided good visual outcomes in cataract patients with extreme myopia. These patients should undergo careful evaluation to determine the maculopathy severity level before surgery.

Sign in / Sign up

Export Citation Format

Share Document