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Niepel G - - 1990
Transient electroretinograms to a reversing color-contrast checkerboard pattern (P-ERG) were recorded in a protanomalous, a deuteranomalous, and a normal observer. Alternate monochromatic checks were of constant wavelength (630 nm red-531 nm green), while the relative energies were varied systematically. When changing the radiance ratio 630 nm-531 nm of the stimulus, ...
Breitmeyer B G - - 1990
The magnitudes of metacontrast masking and of stroboscopic motion were investigated as a function of the color of isoluminant backgrounds on which the stimuli consisting of rectangular-shaped luminance decrements appeared. White, green, and red backgrounds were employed. Background isoluminance was obtained by minimal flicker settings with heterochromatic flicker of uniform ...
Adams R J - - 1990
We used an habituation procedure to explore newborns' ability to detect successive changes in luminance and based on those data, their ability to discriminate chromatic from achromatic stimuli. Newborns were very insensitive to successive changes in luminance: after habituating to a white square of given luminance, they showed no evidence ...
Poirson A B - - 1990
When plotted in three-dimensional color-space, thresholds of colored lights fall on or near the surface of an ellipsoid. Using data reported in the literature, we estimate the deviation between sets of spectral threshold measurements and the ellipsoid that passes closest to the data. Seventy-three percent of the reported spectral thresholds ...
Duncker G - - 1990
Several visual functions were examined before and during self-application of therapeutic doses of digitoxin. The ERG recordings showed a reduction of the critical flicker fusion frequency from 70 Hz to 35-40 Hz. Recovery of color vision after macular photostress was examined with Nagel's anomaloscope and Jaeger's tritanomaloscope. After digitoxin intake ...
Jordan J R JR - - 1990
Although previous research has shown that depth perception is weak for isoluminant stereograms, the possibility remains that color plays an important role in stereopsis when luminance variations are present. To examine this possibility, we measured the relative contribution of chromatic and luminance cues in solving the correspondence problem for ambiguous ...
Van den Berg T J TJ The Netherlands Ophthalmic Research Institute, - - 1989
As a consequence of animal reduction of the light regimes have been tried on patients with retinitis pigmentosa. The trials have been very limited and have not given reason for hope that such reduced light therapy may be beneficial. However, RP patients trying red glasses have reported acute subjective improvement ...
O'Brien W J - - 1989
The purpose of this study was to re-arrange the master Bioform shade guide into a long-range one-dimensional color system based upon color difference. Although most shade guides may show local order when arranged according to hue, long-range order has not been established. However, shade guide arrangement according to a logical ...
Tootell R B - - 1989
To study the functional organization of secondary visual cortex (V2) in the primate, 14C-2-deoxy-d-glucose (DG) was injected while macaque monkeys were shown specific visual stimuli. Wherever possible, patterns of DG uptake were compared with the position of dark and light cytochrome oxidase (cytox) stripes (Tootell et al., 1983). Often, the ...
Neitz J - - 1989
The color vision of three domestic dogs was examined in a series of behavioral discrimination experiments. Measurements of increment-threshold spectral sensitivity functions and direct tests of color matching indicate that the dog retina contains two classes of cone photopigment. These two pigments are computed to have spectral peaks of about ...
Ram R S - - 1989
Photoacoustic spectroscopy, using a PZT transducer, is a quick, direct, and accurate technique to measure ink colors from the absorption region and maximum absorption position.
Watanabe T - - 1989
The present study examined whether color spreading and illusory contours in the neon color spreading effect of Ehrenstein figures are governed by different mechanisms. In the experiment, Ehrenstein figures with colored crosses inserted in the central gaps were used. There were three luminance conditions: the luminance of the Ehrenstein figures ...
Merigan W H - - 1989
Chromatic and achromatic contrast sensitivity were measured in a human observer, 2 normal macaque monkeys, and 3 monkeys with severe toxicant-induced damage to the parvocellular projecting retinogeniculate pathway (P cell-deficient monkeys). Damage to the P pathway was produced by the oral administration of acrylamide monomer (Eskin and Merigan, 1986). Contrast ...
Hovis J K - - 1989
Dichoptic color mixing has been a controversial issue for nearly two centuries. The first dispute arose from the fact that dichoptic color mixtures occur only under certain conditions. A later controversy arose over the implications of dichoptic color mixtures to color vision theories. The present consensus is that dichoptic color ...
Romero J - - 1989
Three chromatic reference stimuli (red, green, and blue) seen under five adaptation conditions (red, green, blue, achromatic, and darkness) were appearance-matched to subsequent color stimuli seen under achromatic conditions. The experimental results have been used to verify the opponent-color color-vision model and also to check the validity of some of ...
Micheli-Tzanakou E - - 1989
An interactive PC-based computer controlled system is described that can be used for collection and analysis of data of Visual Evoked Potentials (VEPs). Visual stimuli are generated on a high-resolution color monitor driven by an Enhanced Graphics Adaptor (EGA). The VEP waveforms are digitized by an A/D converter at a ...
Adams R J - - 1989
Recent anatomical and behavioral evidence suggests that important visual functions like color vision may be severely limited at birth. Therefore, we examined human newborns' ability to discriminate among stimuli of different wavelength by habituating them to a 16 degrees chromatic square of widely varying luminance (as wide as 1.1 log ...
Haenen H T - - 1989
A new method to control the averaging process and to check the stability of evoked potential (EP) components is described. The principle of the method is based on the display of the consecutive averages of the EP after each stimulus in a color-coded picture. In this way the evolution of ...
Cavanagh P - - 1989
The colors, textures, and shapes of shadows are physically constrained in several ways in natural scenes. The visual system appears to ignore these constraints, however, and to accept many patterns as shadows even though they could not occur naturally. In the stimuli that we have studied, the only requirements for ...
Volbrecht V J - - 1989
Three color-normal observers described the appearance of colors under conditions of temporal induction. One of four inducing fields (unique blue, unique green, unique yellow, unique white) was foveally viewed for 5 sec followed immediately by a 400 msec reference stimulus of the same size (0.75 deg) and spatial location as ...
Uchikawa H - - 1989
Color samples selected from the OSA Uniform Color Scales set were seen isolated in a dark field, illuminated by hidden projectors. These appeared as self-luminous aperture colors when thus isolated. We employed a categorical color-naming procedure to assess color appearance. Achromatic surrounds of 33 min width, if adjacent to samples ...
Saito H H NHK Science and Technical Research Laboratories, Tokyo, - - 1989
Based on the fact that a great majority of cells in the middle temporal (MT) area of the macaque respond to movement of luminance contours with directional selectivity, this area has been thought to be concerned with the analysis of visual motion. However, objects can be discriminated from the background ...
Neumeyer C - - 1989
Spectral sensitivity of the goldfish was measured under white room light of 5 lx and 1.5 lx illuminance, using a behavioral training technique. Compared with the result obtained under 25 lx (Neumeyer, 1984), the functions differed remarkably in the mid- and longwave spectral ranges. Under 1.5 lx, the longwave maximum ...
Stevenson J G - - 1989
Literature reports of good correlation between two-dimensional color Doppler and ventriculography for estimation of the severity of atrioventricular valve regurgitation have appeared. Local experience has been variable. The purpose of this study was to evaluate three factors for their effect on two-dimensional color Doppler display of the apparent area of ...
Uchikawa K - - 1989
Color samples selected from the OSA Uniform Color Scales set were viewed without any surround. Separate light sources were used to illuminate the samples and to control the state of adaptation of the subject, thereby separating two factors that are normally confounded. A color-naming procedure was used to assess shifts ...
Geri G A - - 1988
The directional sensitivity (DS) of the red (pi 5), green (pi 4), and blue (pi 1) color mechanisms was measured for both the horizontal and vertical pupil meridians, thus localizing the peak of each pi-mechanism DS function within the two-dimensional pupillary aperture. In the horizontal meridian, there were greater differences ...
Webster M A - - 1988
We have used a factor analysis of the Stiles-Burch [Opt. Acta 6, 1 (1959)] 10 degrees field color matches to examine the basis of individual differences in the color matches made by observers with normal color vision. The differences in the matches are primarily due to interobserver variations in the ...
Blackwell K T - - 1988
In order to study color constancy, the color appearance of the center of a center-surround paradigm was measured by using multiple-alternative forced-response matching. The center was presented with (1) no surround, (2) an adjacent chromatic surround, or (3) a chromatic surround separated from the center by an achromatic gap. The ...
Rosenstiel S F - - 1988
Certain variables were tested for their influence on the color of ceramic metal restorations. The variables included firing temperature, condensation technique, modeling liquid, and brand of porcelain. In addition, the color of different nominal shades was compared. The color was measured with a Minolta CR-121 small-area colorimeter. The small (7 ...
Binzel R P - - 1988
Time-resolved multicolor photometric observations of Pluto-Charon mutual events have been used to derive individual colors for these two bodies and to investigate the degree of color differences between their synchronous facing and opposite hemispheres. Pluto is significantly redder than Charon, where direct measurements of the anti-Charon hemisphere of Pluto and ...
Schmeisser E T - - 1988
Detecting a target in a visually noisy back-ground depends on the ability of the observer to discriminate the target from the surrounding terrain. Visible laser irradiation at less than damage levels may act as a masking source by reducing the observer's ability to resolve differences in the visual scene. The ...
Korth M - - 1988
Previous studies on color vision using the electroretinogram or the evoked potential have concentrated only on brightness and hue but not on the saturation of color. In the present investigation patterns of alternate stripes of a highly saturated color and a totally desaturated color (= white) of equal brightness were ...
Arden G - - 1988
We report a method for computer enhancement of color vision tests. In our graphics system 256 colors are selected from a much larger range and displayed on a screen divided into 768 x 288 pixels. Eight-bit digital-to-analogue converters drive a high quality monitor with separate inputs to the red, green, ...
Livingstone M - - 1988
Anatomical and physiological observations in monkeys indicate that the primate visual system consists of several separate and independent subdivisions that analyze different aspects of the same retinal image: cells in cortical visual areas 1 and 2 and higher visual areas are segregated into three interdigitating subdivisions that differ in their ...
Tootell R B - - 1988
Using spatially diffuse stimuli (or sinusoidal gratings of very low spatial frequency), levels of 14C-2-deoxy-d-glucose (DG) uptake produced by color-varying stimuli are much greater than those produced by luminance-varying stimuli in macaque striate cortex. Such a difference in DG results is consistent with previous psychophysical and electrophysiological results from man ...
Jiménez del Barco L - - 1988
The differential chromaticity thresholds of three color stimuli have been determined from metameric matches carried out during the cone-plateau period after photopigment bleaching. The results are compared with some recently published ones [E. Hita, L. Jiménez del Barco, and J. Romero, J. Opt. Soc. Am. A 3, 1203 (1986)] obtained ...
Biederman G B - - 1988
In a procedure intended to determine color preference in pigeons (which partially replicated Catania, Owens, & von Lossberg, 1983), two keys were illuminated by different colors drawn from a set of amber, red, green, or blue stimuli; this was followed by the presentation of grain when either of the two ...
Moffitt K - - 1988
A visual perception experiment was conducted to determine the chromatic aftereffects of viewing a yellow-green field that simulated the display of current night vision goggles. Six females and two males served as subjects in a color-naming procedure. Subjects sequentially viewed an adaptation field, which was either yellow-green or white, and ...
Ejima Y - - 1988
The threshold-duration functions were determined for a 520-, 570-, or 650-nm test presented upon the various monochromatic backgrounds. The variation of the threshold-duration functions with the background intensity, taken with the 520- or 650-nm test, showed a strong dependence on the background wavelength. This wavelength difference became prominent for the ...
Lennie P - - 1988
We review the physiological and psychophysical research on mechanisms of color vision. Psychophysical work has led to the formulation of explicit theories of the early stages of color vision. The principal postulates of these theories have been confirmed by physiologists (e.g., the existence of three classes of receptors and second-stage ...
Takahashi S - - 1988
Colored afterimages were obtained after the eye was exposed to the adapting field consisting of the figure-ground configuration of colored lights with the same hue and different saturation. When a colored patch was surrounded by a more saturated field, the color of the afterimage was similar to that of the ...
Mollon J D - - 1988
We confirm a remarkable but forgotten property of human color vision that was described over 50 years ago by Tyndall [J. Opt. Soc. Am 23, 12 (1933)]: if wavelength discrimination is measured in the region of 455 nm, the sensitivity of the eye improves when a large fraction of the ...
MacLeod C M - - 1988
Three experiments varied the extent of practice in an analog of the Stroop color-work task. Each experiment involved four phases: (a) baseline naming of four familiar colors, (b) training in consistently naming four novel shapes by using the names of the same four colors, (c) naming the colors when they ...
Werner A - - 1988
A multicolored display was illuminated by 3 bands of wavelengths corresponding to the maxima of the spectral sensitivities of the 3 types of photoreceptors found in the bee retina. The intensity of each band could be varied individually. The light fluxes emitted by the colored areas of the multicolored display ...
Muller R H - - 1987
A colorimetric analysis of white-light interference colors for transparent films on absorbing substrates has shown that specific angles of incidence exist for which the purity of interference colors is predicted to be greatest for s- or p-polarized light. These optimum angles of incidence depend primarily on the optical constants of ...
Emmerson P G - - 1987
The effects of human visual chromatic adaptation underwater are usually reported in subjective terms. The present study aimed to generate data that could be discussed within the internationally recognized CIE color metric. Adaptation was assessed in two underwater environments (blue and green backgrounds). Divers were required to color match stimuli ...
Seaber J H - - 1987
After using video display terminals (VDT), some persons notice that achromatic patterns appear faintly colored hours after terminal use. We investigated the incidence of this effect, the McCollough effect (ME), among 125 VDT users. Subjects completed a questionnaire regarding work habits and certain life-style aspects. They were shown photographs of ...
Meyer G E - - 1987
Two experiments examined the dependence of illusory colors on boundary salience and depth stratification by using flicker-induced depth. The first used a subjective-contour stimulus that appeared as a translucent colored rectangle covering a set of inducing circles and a dark background. The circles were then flickered so as to be ...
Yu F T - - 1987
A microchannel spatial light modulator-based white-light optical processor is presented. The basic principle of the system performance is studied. The operating characteristics of the spectral and contrast responses are measured. Applications to real-time optical processing operations which include the intensity color encoding analog hard clipping in colors are provided.
Sheedy J E - - 1987
Color constancy refers to the phenomenon that the perceived colors of objects are largely unaltered by changes in the illuminant or by viewing through colored filters. Deviations from perfect constancy, induced by filters similar to ophthalmic tints, were investigated in this study. Munsell color chips were forced-choice categorized into R, ...
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