We found rhythmic oscillations in visual contrast sensitivity time locked to the execution of a voluntary reaching action. Three aspects appear particularly relevant. First, the oscillations emerge a long time before the action onset. Second, the action was not visually guided, all visual information being completely irrelevant for motor planning and execution. Third, oscillations were found for targets presented in both the left and right visual hemifields. The present results strongly suggest an automatic nonspecific coupling between early motor planning and early visual processing, possibly mediated by transient synchronization of motor and visual neuronal activities.. The observed rhythmicity in visual contrast sensitivity is the likely behavioral signature of oscillatory activity in visual areas within the theta band. Previous studies have established a firm relationship between the probability of perceiving a near-threshold visual stimulus and the prestimulus phase of ongoing cortical ...
Mars Letter Contrast Sensitivity Test. Identifying functional losses in low contrast perception (often associated with glare sensitivity). Buy online.
Objectives: To determine whether blurred vision caused by exposure to triethylamine (TEA) can be detected by the measurement of contrast sensitivity. Methods: 41 cold box core makers of three foundries and 82 control workers were examined. A detailed ocular and medical history was obtained from the subjects. The contrast sensitivity of the core makers was measured on Monday and Friday of the same week both before and immediately after work and also on a third day, when air samples of TEA were collected. Contrast sensitivity and visual acuity were measured by optotype figures at full contrast, 2.5% contrast, and 0.6% contrast. The changes in contrast sensitivity were used for the analysis. The results of binocular vision and the results of the dominant eye were analysed. Urine specimens for the analysis of TEA were collected on every occasion when contrast sensitivity was measured. Results: 78% of the core makers had had symptoms of blurred vision, and31% had had trouble driving or working. The ...
Purpose: : To evaluate human achromatic spatial contrast sensitivity (CSF) with transient visual evoked cortical potential (tVECP). To compare electrophysiological and psychophysical measurements. Methods: : Six healthy subjects (21 ± 2 years-old) were monocularly tested. The stimuli were black and white horizontal sinusoidal gratings, 40 cd/m2 mean luminance, presented in a 5º circular patch. Six spatial frequencies were used: 0.4, 0.8, 2, 4, 8, and 10 cycles per degree (cpd), in 1 Hz squarewave reversal mode. Electrophysiological contrast thresholds were estimated by linear regressions fitted to data point representing P100 tVECP amplitude as a function of log contrast, extrapolated to zero amplitude. Psychophysics measurements were performed in the same spatial frequencies plus 1 and 6 cpd, using identical spatio-temporal configuration as used in tVECP experiments (dynamic presentation) and using stationary stimuli (static presentation). Psychophysical contrast sensitivity was obtained ...
Contrast sensitivity function is decreased in many disease entities notably: cataract, age related macular degeneration and glaucoma. It is also lowered in individuals that undergo kerato-refractive surgery procedures. Traditional contrast sensitivity tests printed on charts are limited in the fact that a certain working distance is needed and are prone to degradation due to use. The electronic M&S Smart System contrast sensitivity testing unit provides the flexibility to use at variable distance and provides better resolution capabilities especially at lower contrast due to the visual display system. The purpose of the study was to evaluate the short-term repeatability and use of Landolt C contrast sensitivity function test in ocular healthy and in individuals with decreased visual function.. ...
Contrast discrimination is an important type of information for establishing image quality metrics based on human vision. We used a dual-masking paradigm to study how contrast discrimination can be influenced by the presence of adjacent stimuli. In a dual masking paradigm, the observers task is to detect a target superimposed on a pedestal in the presence of flankers. The flankers (1) reduce the target threshold at zero pedestal contrast; (2) reduce the size of pedestal facilitation at low pedestal contrasts; and (3) shift the TvC (Target threshold vs. pedestal contrast) function horizontally to the left on a log-log plot at high pedestal contrasts. The horizontal shift at high pedestal contrasts suggests that the flanker effect is a multiplicative factor that cannot be explained by previous models of contrast discrimination. We extended a divisive inhibition model of contrast discrimination by implementing the flanker effect as a multiplicative sensitivity modulation factor that account for ...
The observed shift in the contrast gain function is consistent with previous measures of spatial vision loss with age. For instance, Sloane, Owsley, and Jackson (1988) measured contrast sensitivity for young and old observers with spatial frequencies ranging from 0.5 to 8 c/deg and luminance levels ranging from mesopic to photopic. At a low temporal frequency, the slope of the sensitivity function (inverse of the threshold function) spanning the range of luminance was steeper for older than younger observers at spatial frequencies below 4 c/deg. This means that older observers required more contrast at low luminance levels to detect a sine-wave grating than their younger counterparts. This pattern of contrast sensitivity loss is consistent with a reduction in the contrast gain slope of the underlying mechanism at low spatial frequencies. In addition, suprathreshold measures of spatial vision performance also support a reduction in contrast gain within one (or both) of the pathways. Losses in ...
The observed shift in the contrast gain function is consistent with previous measures of spatial vision loss with age. For instance, Sloane, Owsley, and Jackson (1988) measured contrast sensitivity for young and old observers with spatial frequencies ranging from 0.5 to 8 c/deg and luminance levels ranging from mesopic to photopic. At a low temporal frequency, the slope of the sensitivity function (inverse of the threshold function) spanning the range of luminance was steeper for older than younger observers at spatial frequencies below 4 c/deg. This means that older observers required more contrast at low luminance levels to detect a sine-wave grating than their younger counterparts. This pattern of contrast sensitivity loss is consistent with a reduction in the contrast gain slope of the underlying mechanism at low spatial frequencies. In addition, suprathreshold measures of spatial vision performance also support a reduction in contrast gain within one (or both) of the pathways. Losses in ...
This study aimed to explore the neural development status of the visual system of children (around 8 years old) using contrast sensitivity. We achieved this by eliminating the influence of higher order aberrations (HOAs) with adaptive optics correction. We measured HOAs, modulation transfer functions (MTFs) and contrast sensitivity functions (CSFs) of six children and five adults with both corrected and uncorrected HOAs. We found that when HOAs were corrected, children and adults both showed improvements in MTF and CSF. However, the CSF of children was still lower than the adult level, indicating the difference in contrast sensitivity between groups cannot be explained by differences in optical factors. Further study showed that the difference between the groups also could not be explained by differences in non-visual factors. With these results we concluded that the neural systems underlying vision in children of around 8 years old are still immature in contrast sensitivity.
Human contrast sensitivity to visual patterns vs. model predictions.a, Probability distribution of the 512 possible 3×3 1-bit pixel patterns (grey histogram).
Rabin Contrast Sensitivity (CS) Test. Contrast sensitivity test comparable to the Small Letter Contrast Test. Buy online from Precision Vision!
To evaluate the effects on contrast sensitivity (CS) measurements of intravitreal bevacizumab injections associated with standard metabolic control in eyes
With the increasing rise of toxicity, and the increasing awareness of this huge problem, we need to have ways of determining which patients are likely to b
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Contrast response functions (CRFs) for the VEP were obtained with a Discrete Fourier Transform (DFT) technique employing swept contrast gratings. VEP CRFs in infants were found to have a form similar to those observed in adults, being linear functions of log contrast over a range of near-threshold c …
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Neural activity during repeated presentations of a sensory stimulus exhibits considerable trial-by-trial variability. Previous studies have reported that trial-by-trial neural variability is reduced (quenched) by the presentation of a stimulus. However, the functional significance and behavioral relevance of variability quenching, and the potential physiological mechanisms that may drive it have rarely been studied. Here we recorded neural activity with EEG as subjects performed a two-interval forced-choice contrast discrimination task. Trial-by-trial neural variability was quenched by approximately 40% after the presentation of the stimulus, relative to the variability apparent before stimulus presentation, yet there were large differences in the magnitude of variability quenching across subjects. Individual magnitudes of quenching predicted individual discrimination capabilities such that subjects who exhibited larger quenching had smaller contrast discrimination thresholds and steeper ...
04.02.2019 ► Spatial resolution is a key property of eyes when it comes to understanding how animals perceive visual signals. In the current paper (J. Vision), Matteo Santon et al. describe the contrast sensitivity function of a small, benthic marine triplefin fish, using an optokinetic reflex approach. Compared to other fish, the authors conclude that such reflex seems to be adapted to process low spatial frequency information from stimuli in the peripheral visual field and show that small marine fish can feature excellent contrast sensitivity at optimal spatial frequency. ...
A multiresolution-analysis-based local contrast transform is proposed to enhance local structures in x-ray images. The local contrast is defined as a ratio of the local intensity variation to the local mean. With wavelet multiresolution decomposition, the detail coefficients and approximation coefficients are interpreted, respectively, as local variations and local averages in virtue of the localization property of wavelet transform. Based on the local contrast transform, an algorithm is developed to modify coefficients before wavelet synthesis. An across-scale local contrast is obtained when the scale associated with the local variation is different from that of the local mean. The nonlinearity and local adaptiveness properties of local contrast transform result in structural enhancement in local dark regions in the reconstructed images. We applied this technique to deboned poultry inspection using x-ray images. Because of its high x-ray absorption, a foreign inclusion appears as a ...
Measuring eyesight for drivers involves several different important categories of vision. A positive result of Visual Acuity Screening is that it ensures that signs and other critical markings in the roadway environment (lane markings) would be adequately legible to most drivers. Thus a minimum level to driving in Ireland, with 2 functioning eyes, is 6/12 for Group 1 applicants (A1, A, B,EB, M or W) and 6/7.5 for Group 2 applicants (C1, C, EC1, EC, D1, D, ED1, ED), trucks, buses etc Contrast sensitivity refers to the amount of contrast a person needs in order to detect or identify an object or pattern in varying light levels. Think of trying to read the eye chart through a fog. A fog that is getting more and more dense. A person who has poor contrast sensitivity requires a higher contrast to see objects or patterns from a person who has good contrast sensitivity i.e. they need a more stark black on white difference. Impairment of contrast sensitivity can result from a number of different eye and ...
TY - CHAP. T1 - Fixation, contrast sensitivity and childrens reading. AU - Cornelissen, P. PY - 1993. Y1 - 1993. M3 - Chapter. SN - 0-444-89949-9. VL - 3. T3 - Studies In Visual Information Processing. SP - 139. EP - 162. BT - Facets of dyslexia and its remediation. ER - ...
Can anybody suggest some colors and simple fonts fot text (heading) on a grey background. Please check the image attached. Thank you!
Nodes with grey background indicate a prediction accuracy for the nodes greater than 0.6. Isolated nodes do not have connections due to the structure difference
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Test for quick measurement of low contrast visual acuity at 25%, 10%, 5%, 2.5%, and 1.25% contrast by measuring the distance where the symbols are seen. 10M symbols correspond to visual acuity 0.10 at 1 m, 0.05 at 0.5 m and 0.3 at 3 m. VA values are thus easy to calculate. Test includes a ...
We assessed the accuracy of contrast-defined shape detection of stimuli of constant aspect ratio, namely, circular bandpass stimuli whose radii were sinusoidally varied about a mean radius. Performance for these contrast-defined shapes, which we show is determined by the global rather than the local attributes of the stimulus, is 2-8 times worse than that for their luminance-defined counterparts, suggesting separate processing limitations. By spatially and orientationally filtering the two-dimensional fractal-noise carriers of which these stimuli were composed, we determined whether there are specific rules concerning the spatial and orientational input to shape detectors from mechanisms sensitive to the carrier structure. The results suggest that second-order circularity detectors receive mixed input from spatial-frequency-tuned and orientationally tuned cells.. © 2001 Optical Society of America. Full Article , PDF Article ...
Principal Investigator:KAJITA Etsuko, Project Period (FY):1997 - 1998, Research Category:Grant-in-Aid for Scientific Research (C), Section:一般, Research Field:Nursing
This dataset contains contrast measurements at luminances from 0.02 cd/m^2 (mesopic) to 7000 cd/m^2 (photopic). The stimuli were Gabor patches at f = 0.5, 1, 2, 4, 6 cpd in three colour directions. Please refer to README.md for further details. For more information, please also see the project page: https://www.cl.cam.ac.uk/research/rainbow/projects/hdr-csf ...
Dynamic Vision Sensors (DVS) have recently appeared as a new paradigm for vision sensing and processing. They feature unique characteristics such as contra
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The CyberPower Smart App Sinewave PR1000LCD uninterruptible power supply (UPS) with LCD Control Panel and Active PFC compatible pure sine wave output safeguards mission-critical servers, telecom equip
TY - JOUR. T1 - Differential impact of exogenous and endogenous attention on the contrast sensitivity function across eccentricity. AU - Jigo, Michael. AU - Carrasco, Marisa. N1 - Funding Information: We thank Antoine Barbot, Rachel Denison, Antonio Fern?ndez, David Heeger, Michael Landy, and Jonathan Winawer for their helpful comments, as well as Maya Mosley for assistance in data collection. Funded by National Institutes of Health R01-EY019693 and NEI R21-EY026185 to MC. Publisher Copyright: © 2020 Association for Research in Vision and Ophthalmology Inc. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.. PY - 2020. Y1 - 2020. N2 - Both exogenous and endogenous covert spatial attention enhance contrast sensitivity, a fundamental measure of visual function that depends substantially on the spatial frequency and eccentricity of a stimulus. Whether and how each type of attention systematically improves contrast sensitivity across spatial frequency and eccentricity are fundamental to ...
The goal of this study was to predict visual acuity (VA) and contrast sensitivity function (CSF)with tissue redness grading after pterygium surgery. A total of 67 primary pterygium participants were selected from patients who visited an ophthalmology clinic. We developed a semi-automated computer program to measure the pterygium fibrovascular redness from digital pterygium images. The final outcome of this software is a continuous scale grading of 1 (minimum redness) to 3 (maximum redness). The region of interest (ROI)was selected manually using the software. Reliability was determined by repeat grading of all 67 images, and its association with CSF and VA was examined. The mean and standard deviation of redness of the pterygium fibrovascular images was 1.88 ± 0.55. Intra-grader and inter-grader reliability estimates were high with intraclass correlation ranging from 0.97 to 0.98. The new grading was positively associated with CSF (p , 0.01) and VA (p , 0.01). The redness grading was able to ...
Fingerprint Dive into the research topics of Visual function of a patient with advanced adrenoleukodystrophy: Comparison of luminance and color contrast sensitivities. Together they form a unique fingerprint. ...
Purpose: AMD is one of the leading causes of vision loss globally. Since color vision impairment is often one of the first symptoms of retinal disease, earlier AMD detection may be possible using color vision screenings. This potential detection could result in earlier treatment and decreased progression of the disease before irreversible damage to sight occurs.. Methods: Patients from the Illinois Eye Institute and Chicago Eye Institute were asked to perform the King Devick Variable Color Contrast Sensitivity(VCCSC) iPad test monocularly at their best corrected near visual acuity with black, red, blue, green, and yellow letters at various contrast levels (100%,75%,50%, and 25%). Identification accuracy (out of 5 letters) was recorded as both color and contrast changed.. Results: Data was analyzed using SPSS v21. All values are presented as means±SEM. The control group (n=35) age 50-79 years (46% male, 54% female). The non-exudative (NE) AMD(n=26) age 60-82 years (67% male, 33% female). A ...
At the recent ESCRS meeting in London, Dr David Evans participated as a faculty member in a course about contrast sensitivity (CS). Dr Gregory Pamel was the Course Director. During the course, Dr Evans covered the scientific basis of testing contrast sensitivity with sine-wave gratings and how it compares to standard visual acuity as a measure for real-world vision. Dr Pamel provided detailed information about the clinical significance of contrast sensitivity testing for cataract documentation, evaluation of refractive surgery outcomes and the use of CS testing to aid in evaluating the need for and results of re-treatments after initial refractive surgery. He also provided the most recent CS findings for new methods of presbyopia correction, including FDA trial data from ReVision Optics and AcuFocus. Dr Pamel then shared his thoughts about the importance of preserving patient quality of vision when correcting presbyopia and how CS testing is an important metric to determine the best outcomes. ...
The perception of speed is influenced by visual contrast. In primary visual cortex (V1), an early stage in the visual perception pathway, the neural tuning to speed is directly related to the neural tuning to temporal frequency of stimulus changes. The influence of contrast on speed perception can be caused by the joint dependency of neural responses in V1 on temporal frequency and contrast. Here, we investigated how tuning to contrast and temporal frequency in V1 of anesthetized mice are related. We found that temporal frequency tuning is contrast-dependent. V1 was more responsive at lower temporal frequencies than the dLGN, consistent with previous work at high contrast. The temporal frequency tuning moves toward higher temporal frequencies with increasing contrast. The low half-maximum temporal frequency does not change with contrast. The Heeger divisive normalization equation provides a good fit to many response characteristics in V1, but does not fit the dependency of temporal frequency and
TY - JOUR. T1 - Reaction time to motion onset of luminance and chromatic gratings is determined by perceived speed. AU - Burr, David C.. AU - Fiorentini, Adriana. AU - Morrone, Concetta. PY - 1998/12. Y1 - 1998/12. N2 - We measured reaction times for detecting motion onset for sinusoidal gratings whose contrast was modulated in either luminance or chromaticity, for various drift rates and contrasts. In general, reaction times to chromatic gratings were slower than to luminance gratings of matched cone contrast, but the difference in response depended critically on both contrast and speed. At high image speeds there was virtually no difference, whereas at low speeds, the difference was pronounced, especially at low contrasts. At high image speeds there was little dependence of reaction times on contrast (for either luminance or colour), whereas at low speeds the dependence was greater, particularly for chromatic stimuli. This pattern of results is reminiscent of those found for apparent speed of ...
Far contrast sensitivity (ie, the ability to detect slight changes in luminance before they become indistinguishable) was assessed binocularly with the participants best spectacle correction at a distance of 3 m using the Vector Vision CSV 1000 illuminated box (one site) and the Vision Contrast Test System (other site). Contrast sensitivity was assessed at spatial frequencies of 1.5, 3, 6, 12, and 18 cycles per degree (cpd). For CSV 1000, contrast sensitivity was not measured at spatial frequency 1.5 cpd because there was no option for this frequency. Raw scores were transformed to logMar (logarithm of the minimum angle of resolution) units. A higher numeric value represents better contrast sensitivity ...
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The CSF represents the reciprocal of the minimum contrast required to detect sinusoidal gratings that vary in spatial frequency (the number of cycles per degree of visual angle, cpd). As shown in the top panel of figure 3, scotopic CSFs were found to be low pass for all age groups. Statistically significant age related declines in contrast sensitivities were found for spatial frequencies at or below 1.2 cpd. This greater loss in contrast sensitivity at low spatial frequencies is quite different from photopic contrast sensitivity changes with age in which the decline in sensitivity is only at higher spatial frequencies for luminance varying stimuli.26,27 An analysis of these results in terms of optical factors could be rejected, while the results are consistent with age related changes in scotopic neural pathways.. The bottom panel of figure 3 shows the highest spatial frequency (the CSF cut-off frequency) that can be detected under scotopic conditions as a function of age. The axis on the ...
Laser in situ keratomileusis (LASIK) surgery has been performed worldwide since 1990. Historically, LASIK has been reported to decrease contrast sensitivity post operatively and patients have been advised to take the day off of work and potentially the day after LASIK. More recently, utilizing advanced laser technology for optimized corneal ablation and creation of the flap has the potential for improved LASIK surgery results and improved recovery time. Visual recovery and management of immediate post operative visual acuity is important for patient satisfaction ...
A new contrast sensitivity system was built with an iPAD connected to a 24 TFT-screen TFT monitor with a HDMI cable. The monitor was calibrated with a colorimeter. An image, showing incrementing spatial frequency along the x-axis and decreasing contrast along the Y-axis, was generated with custom software that allowed imaging on the the iPAD or the TFT monitor. While watching the image on the TFT monitor at 5 m, the subject was asked to draw a line in between contrast perceived and no contrast perceived. The line drawn by the subject was shown on the screen in use after the end of the tracking. The contrast perceived at each spatial frequency was stored in a data file. Totally, 20 subjects with visual acuity 1.0 and no known eye pathology were randomized on 2 groups with 6 males and 4 males to be measured for contrast sensitivity on both eyes with Vistech 6500 chart or UCST, depending on group belonging. Spectral contrast sensitivity was recorded for each eye and the time consumed for ...
PURPOSE: Loss of neuroretinal structure and function, ascribed to a HIV-associated Neuroretinal Disorder (HIV-NRD), in the absence of ocular opportunistic infections, has been reported in HIV-infected individuals treated with combination antiretroviral therapy (cART). Whether HIV-infected individuals with prolonged well-suppressed infection remain at risk for HIV-NRD, is unknown. METHODS: Ninety-two HIV-infected men with suppressed viremia on cART for at least 12 months (HIV+) and 63 HIV-uninfected, highly comparable, male controls (HIV-), aged at least 45 years, underwent functional measurements of spatial (Pelli Robson contrast sensitivity [PR CS]) and temporal contrast sensitivity (TCS) and straylight, as well as spectral-domain optical coherence tomography analysis measured total and individual retinal layer thickness ...
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Background: Amblyopic observers present abnormal spatial interactions between a low-contrast sinusoidal target and high-contrast collinear flankers. It has been demonstrated that perceptual learning (PL) can modulate these low-level lateral interacti
Purpose: To investigate whether a small angle glare test in a clinical setting can produce and detect a significant decrease in contrast sensitivity with age in normal young and elderly eyes. Methods: Contrast sensitivity (CS), with and without glare, was measured in 20 subjects. The subjects were all fully corrected. CS was measured using the Freiburg Visual Acuity & Contrast Test (FrACT) software running on a Macintosh imac (CRT). In our set-up the software uses a 4AFC-method, and the test distance was 4 meters. Glare was induced by a Fostec DCR® II light source with a randomised fiberoptical bundle mirrored into the centre of a Landolt C test target. Full test symmetry was accomplished by using this glare set-up. The test target and the glare source subtended an angle of about 1.3° and 0.2° respectively, yielding a 0.5° glare angle. The target mean luminance was 61 cd/m2 and the illuminance at the eye was 15 lux with glare. Results: We measured 20 subjects (20 to 59 yrs) with no known ...
It oversees the development of new device technologies such as sources and detectors as components, active elements such as modulators/switches, integration of optical components to perform various functions, development of active optical system/subsystem technologies including hardware, propagation considerations, and beam manipulation techniques.
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Ive heard about this a while ago, but now its statistically proven. Shooting Games can increase/help a players vision. It has to do with Contrast Sensitivity, apparently shooting games (Like Call of Duty 4 or Halo 3) increase and exercise your Contrast Sensitivity. What is contrast sensitivity? It is your ability to notice tiny changes…
Contrast Downloads. MSU Smart Brightness & Contrast - Free high-qualitybrightness & contr plugin for VirtualDub. CrispyPix - Brighten and sharpen images, zoom, adjust contrast...all from inside Microsoft Internet Explorer. Right-click on the image and you get an easy-to-use interface. Buy it now, or download a free trial
We present a spatial frequency domain multiplexing method for extending the imaging depth range of a SDOCT system without any expensive device. This method uses two reference arms with different round-trip optical delay to probe different depth regions within the sample. Two galvo scanners with different pivot-offset distances in the reference arms are used for spatial frequency modulation and multiplexing. While simultaneously driving the galvo scanners in the reference arms and the sample arm, the spatial spectrum of the acquired two-dimensional OCT spectral interferogram corresponding to the shallow and deep depth of the sample will be shifted to the different frequency bands in the spatial frequency domain. After data filtering, image reconstruction and fusion the spatial frequency multiplexing SDOCT system can provide an approximately 1.9 fold increase in the effective ranging depth compared with that of a conventional single-reference-arm full-range SDOCT system ...
Computational modeling is a useful method for generating hypotheses about the contributions of impaired neurobiological mechanisms, and their interactions, to psychopathology. Modeling is being increasingly used to further our understanding of schizophrenia, but to date, it has not been applied to questions regarding the common perceptual disturbances in the disorder. In this article, we model aspects of low-level visual processing and demonstrate how this can lead to testable hypotheses about both the nature of visual abnormalities in schizophrenia and the relationships between the mechanisms underlying these disturbances and psychotic symptoms. Using a model that incorporates retinal, lateral geniculate nucleus (LGN), and V1 activity, as well as gain control in the LGN, homeostatic adaptation in V1, lateral excitation and inhibition in V1, and self-organization of synaptic weights based on Hebbian learning and divisive normalization, we show that (a) prior data indicating ...
Disclosed herein are systems and methods for calibrating a continuous analyte sensor, such as a continuous glucose sensor. One such system utilizes one or more electrodes to measure an additional analyte. Such measurements may provide a baseline or sensitivity measurement for use in calibrating the sensor. Furthermore, baseline and/or sensitivity measurements may be used to trigger events such as digital filtering of data or suspending display of data.
We used a cross-modal dual task to examine how changing visual-task demands influenced auditory processing, namely auditory thresholds for amplitude- and frequency-modulated sounds. Observers had to attend to two consecutive intervals of sounds and report which interval contained the auditory stimulus that was modulated in amplitude (Experiment 1) or frequency (Experiment 2). During auditory-stimulus presentation, observers simultaneously attended to a rapid sequential visual presentation-two consecutive intervals of streams of visual letters-and had to report which interval contained a particular color (low load, demanding less attentional resources) or, in separate blocks of trials, which interval contained more of a target letter (high load, demanding more attentional resources). We hypothesized that if attention is a shared resource across vision and audition, an easier visual task should free up more attentional resources for auditory processing on an unrelated task, hence improving auditory
Mean age of LCG (48 eyes) was significantly higher(29.26±5.00vs26.45±3.74,P=0.006). F/M ratio was comparable in two groups and 2.7 in total. Post-op CDVA was comparable in two groups(1.22±0.23vs1.25±0.44,P = 0.7). Post-op UDVA was higher in HCG(1.31±0.37vs1.15±0.23,P =0.001). Pre-op mean manifest SE was more myopic in LCG(-4.41±2.02vs-3.28±1.41,P = 0.001) while post-op SE were comparable. Mean post-op photopic and mesopic contrast sensitivities were better in HCG; however mean improvement of contrast sensitivities were higher in LCG. Pre-op mean Defocus and Pentafoil aberrations were higher in LCG. After the operation they became comparable ...
Small changes in contrast sensitivity after LASIK can be documented using a dedicated computer program displaying optotypes on a monitor. Contrast sensitivity is impaired at 1 and 3 months, while complete recovery is observed after 6 months. This course is partly concealed if the spectacle refraction is not taken into account ...
A red background is used for men whose data has not yet been fully analyzed. His position on the tree is not yet final, and will in general be downstream of the current position. He may not be positive for all the SNPs/INDELs in the block he descends from.. Men whose NGS data have been fully analyzed are indicated with a grey background color.. Those men with a grey background and a pink bar to their left have been finalized, but havent gone through as much scrutinity as earlier kits have. In particular, no search has been made for recurrent SNPs or other unusual mutations. For the vast majority of kits, this has no effect at all, but I will review them as necessary in the future.. ...
A red background is used for men whose data has not yet been fully analyzed. His position on the tree is not yet final, and will in general be downstream of the current position. He may not be positive for all the SNPs/INDELs in the block he descends from.. Men whose NGS data have been fully analyzed are indicated with a grey background color.. Those men with a grey background and a pink bar to their left have been finalized, but havent gone through as much scrutinity as earlier kits have. In particular, no search has been made for recurrent SNPs or other unusual mutations. For the vast majority of kits, this has no effect at all, but I will review them as necessary in the future.. ...
Development of Population since 1875 within the Current Boundaries (Blue Line: Population; Dotted Line: Comparison to Population Development of Brandenburg state; Grey Background: Time of Nazi rule; Red Background: Time of Communist rule) Development of Population since 1875 within the Current Boundaries (Blue Line: Population; Dotted Line: Comparison to Population Development of Brandenburg state; Grey Background: Time of Nazi rule; Red Background: Time of Communist rule) Recent Population Development (Blue Line) and Forecasts Recent Population Development (Blue Line) and Forecasts Detailed data sources are to be found in the Wikimedia Commons
We know that adults contrast sensitivity and spatial resolution are better along the horizontal than vertical meridian -a.k.a. horizontal vertical anisotropy (HVA)- and better in the lower than upper vertical meridian -a.k.a. vertical meridian asymmetry (VMA; Carrasco et al., Spatial Vision 2000, JOV 2002). We also know that for adults the speed of information accrual follows the same pattern, i.e. it is faster along the horizontal meridian and slowest at the North locations (Carrasco et al., VSS 2002). In this study, we investigated the developmental course of these asymmetries with children ages 5-12, by using stimuli of different levels of familiarity, such as shapes, letters and numbers. We used a 4AFC character identification task to determine the presence and extent of the HVA and VMA. Each trial consisted of a central fixation point followed by a 1 stimulus, presented for 50 ms. The stimulus appeared at one of 10 possible eccentricities, ranging from 4 to 13 , along each of the 8 ...
An apparatus is disclosed for making unchirped holographic diffraction gratings that are formed from curved lines in a thin film. The gratings so made focus as well as reflect light that is confined to the film incorporating the grating. SU BACKGROUND OF THE INVENTION Gratings have been incorporated in integrated optics devices for several purposes, including the fabrication of distributed feedback lasers, light-wave couplers, and band-rejection filters. Integrated-optics gratings known to the prior art were composed at straight lines, and therefore could not focus the light being processed. Gratings that combine focusing and diffraction were known to be desirable, but the prior art was unable to produce them. The closest prior art that has come to our attention is a method and apparatus for producing curved-line holographic gratings that have unequally spaced, or chirped, lines (U.S. Pat. No. 3,578,845, issued on May 18, 1971 to K. E. Brooks et al). This reference teaches the production of gratings
In this report we present a confocal Raman system to identify the unique spectral features of two proteins, Interleukin-10 and Angiotensin Converting Enzyme. Characteristic Raman spectra were successfully acquired and identified for the first time to our knowledge, showing the potential of Raman spectroscopy as a non-invasive investigation tool for biomedical applications.