Accurately processing orientation information is a fundamental component of visual performance. Single-unit recordings have shown that the orientation tuning of individual neurons in macaque cortical areas V1 and V2 is reduced dramatically with age (M. T. Schmolesky, Y. Wang, M. Pu, & A. G. Leventhal, 2000; S. Yu, Y. Wang, X. Li, Y. Zhou, & A. G. Leventhal, 2006). These researchers suggest that...

The Humphrey 30-2 visual field was examined 9 times before and after an 8-km jog in one subject, whose contrast sensitivity had been found to improve after jogging. The mean deviation improved statistically significantly suggesting better sensitivity of the visual system after jogging. Our results suggest that in some individuals physical exercise influences the factors which lie behind the vis...

Subjective detailedness is the spontaneously perceived overall detailedness of an image. Cursory experience suggests that, for identical objective detailedness, subjective detailedness is higher in small than in large images. While previous studies hint towards a size-dependence of subjective detailedness, they are not conclusive regarding the magnitude, direction and robustness of the effect, ...

Sensitivity to slow movement improves substantially during the early postnatal months. Thresholds were measured for slow oscillatory displacements for 68 infants aged 6, 12, 18, and 24 weeks. Standing wave line stimuli were used; 6-week-olds were tested at 1.2 Hz, and infants in the three older age groups were tested at either 0.6 or 1.2 Hz. Six-week-olds as a group were very insensitive to the...

We investigated the possibility that the spatial imprecision of amblyopic eyes can be accounted for by the relative insensitivity to contrast that has been documented for these eyes. Thresholds for the discrimination of spatial misalignment, a measure of spatial uncertainty, were determined for three amblyopes and one normal for targets ranging in contrast from detection threshold to 99%. We fo...

1. We measured spatial and temporal sensitivity of 81 X-cells and 46 Y-cells in the lateral geniculate nucleus of cats by determining contrast thresholds of single cells to counterphased, sine-wave gratings. The plots of contrast sensitivity (reciprocal of the contrast threshold) as a function of spatial or temporal frequency of the sine-wave grating represent the contrast sensitivity functions...

purpose: to compare aspheric and spherical hydrophilic intraocular lenses (iols) in terms of contrast sensitivity and visual acuity in photopic and mesopic conditions. methods: this triple-blind randomized clinical trial was performed on 40 eyes of 40 patients at al-zahra eye center, zahedan, iran. the eyes were randomized to standard phacoemulsification procedure with spherical (adapt, b&l;) o...

purpose: to investigate the relationship between higher-order aberrations (hoas) and contrast sensitivity function (csf) in myopes. methods: in this cross-sectional study, hoas and csf were measured in myopic eyes over a 6-mm pupil. pupil diameter was measured in photopic condition. the correlation between hoas and csf was investigated using multivariate linear regression analysis. results: sev...

BACKGROUND Perceptual learning has been documented in adult humans over a wide range of tasks. Although the often-observed specificity of learning is generally interpreted as evidence for training-induced plasticity in early cortical areas, physiological evidence for training-induced changes in early visual cortical areas is modest, despite reports of learning-induced changes of cortical activi...