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Rotgold G - - 1997
Light adaptation to illumination that is presented peripherally changes the subjective color of a central Benham disk stimulus. In our experiments we kept the peripheral illumination achromatic and remote (not even adjacent to the test stimulus). Using a high-frame-rate monitor, we produced the subjective color stimulus, to our knowledge for ...
Mullen K T - - 1997
We have tested the independence of red-green chromatic and luminance mechanisms at detection threshold using a method of subthreshold summation. Stimuli were isoluminant red-green gratings and yellow-black luminance gratings that uniquely activate the red-green color and luminance mechanisms, respectively. Stimuli were Gaussian enveloped 0.25, 1 or 4 cpd sinewave gratings, ...
van Trigt C - - 1997
The almost-illuminant-independent achromatic variable zeta [J. Opt. Soc. Am A 11, 1003 (1994)] is supplemented by two achromatic variables, both almost illuminant-independent. The results are numerically verified and obtained by means of so-called (human) visual system-response functions, defined as those linear combinations of the color-matching functions that constitute the best ...
van Trigt C - - 1997
The rationale for color opponency is investigated. A principle of optimal discrimination of visual information is introduced: If two visual variables are kept fixed, the third one, left free, must vary as much as possible. We prove that, if satisfied, the principle requires the existence of two chromatic functions, which ...
D'Zmura M - - 1997
Visual search for targets that combine color and shape features that are shared by distracting items can be conducted spatially in parallel. Experimental results show that parallel search for color/shape conjunctions is possible when the shapes chosen let observers segregate the spatially interspersed items into figure and ground and when, ...
Gerling J - - 1997
We compared electrophysiological responses [pattern-ERG (PERG) and VEP] and psychophysical measures to color stimuli to separate different forms of anomalous color vision. PERG and VEP were recorded from seven normals and 14 subjects with congenital color vision deficiencies. Stimuli were color checkerboards with 0.5 deg check size, phase reversing at ...
Goda N - - 1997
A series of experiments were designed to examine how luminance and color cues influence the occurrence of neon color spreading for the Ehrenstein pattern plus the cross pattern. The proportion of "see" responses for color spreading was obtained for different combinations of the luminance and color of the pattern components. ...
Miyahara E - - 1997
'Color from motion' describes the perception of a spread of subjective color over achromatic regions seen as moving. The effect is produced with a stimulus display consisting of colored dots, randomly placed upon a white field, with dots in the test region differing in both chromaticity and luminance from those ...
Patterson R - - 1997
The search for methods to demonstrate and accurately measure contact area and pressure within human joints has been and remains an active one. Presenssor is a measuring system developed by Fuji Photo Film Co., Ltd. and used in medical applications. The color intensity fades with time and exposure to light. ...
Wilson-Pauwels L - - 1997
Visual cues are powerful tools for directing the user's eyes to relevant information. When incorporated into the design of a medical/scientific illustration, important details are more quickly conveyed. This article discusses the use of line, color, contrast, light and shadow, spatial relationships, image size and location, rhythm, and graphic devices ...
Cicerone C M - - 1997
'Color from motion' describes the perception of a spread of subjective color over achromatic regions seen as moving. The effect can be produced in a display of multiple frames shown in quick succession, each frame consisting of a fixed, random placement of colored dots on a high-luminance white background with ...
Kemp S E - - 1997
We previously found that untrained subjects make nonrandom color matches to odors and that the color matches are stable over time (Gilbert, Martin, & Kemp, 1996). Here we investigate further aspects of the cross-modal associations between vision and olfaction: whether perceptual dimensions of odor vary systemically with those of vision. ...
Accornero N - - 1997
Color visual field analysis has proven highly sensitive for early visual impairments diagnosis in M. S., yet it has never attained widespread popularity usually because the procedure is difficult to standardize, the devices are costly, and the test is fatiguing. We propose a computerized procedure running on standard PC, cost ...
Kabai P - - 1997
Visual discrimination between colors and patterns was studied in telencephalectomized chicks of Japanese quail lines that were artificially selected for early approach preferences for particular colors and patterns. Since these preferences are not conditional on prior learning, they provide an effective experimental paradigm to study visual discrimination without reliance on ...
Allan L G - - 1997
Although there is considerable evidence supporting an associative interpretation of contingent color aftereffects, there are data that appear inconsistent with this interpretation. New findings from seven experiments are presented indicating that, contrary to earlier claims, contingent color aftereffects are observed after induction with (1) single orthogonal black bars on colored ...
Sandusky C L - - 1996
The effects of sample thickness (0.5, 1.0, and 1.5 cm), background color (white, pink, green, and gray), and illuminant (D-65, A, and F) on color measurement of broiler tissue were determined. Color values from the anterior portions of the two Pectoralis superficialis muscles were not different from each other, allowing ...
Lenhard M - - 1996
The aim of this study was to obtain information about tooth color changes in 25 extracted human incisors resulting from repeated bleaching with a 10 percent carbamide peroxide gel. Using a colorimeter, the author recorded color changes in the L*a*b* color space after each bleaching period. The observed tooth color ...
Naikar N - - 1996
One subject with complete forebrain commissurotomy (L.B.), another with posterior callosotomy (D.K.), and eight normal controls were presented with successive pairs of red and/or green lights, on either side of the retinal midline and within the left and right visual fields. All of the subjects could discriminate the direction of ...
Jin E W - - 1996
Color constancy is the perceived stability of the color of objects despite changes in the light illuminating them. An object's color is considered constant if the current perceived color is judged to be in accord with the remembered one. Thus the accuracy and precision of color memory are fundamental to ...
Lucassen M P - - 1996
Color constancy was studied under conditions simulating either natural or extremely artificial illumination. Four test illuminants were used: two broadband phases of daylight (correlated color temperatures 4000 and 25,000 K) and two spectrally impoverished metamers of these lights, each consisting of only two wavelengths. A computer controlled color monitor was ...
Morita T - - 1996
A variety of types of artificial illumination has recently become available, differing in the quality of illumination and range of color temperature. In our previous studies we found that in subjects with normal color vision the nocturnal fall in core temperature and the increase of urinary melatonin excretion were suppressed ...
Corballis M C - - 1996
Pairs of red and green digits were flashed in the opposite visual fields of L.B., a man with complete forebrain commissurotomy. He was highly accurate in naming both digits, the green ones alone, or the red ones alone, regardless of field. In contrast, he was relatively poor at naming the ...
Gegenfurtner K R - - 1996
In recent years the idea of parallel and independent processing streams for different visual attributes has become a guiding principle for linking the organization, architecture and function of the visual system. Findings concerning the segregation of motion and color information have been at the forefront of the evidence in favor ...
Wray J - - 1996
It is known that the perceived color of an object depends on the context in which it is viewed, its reflectance properties and the spectral distribution of the illuminating light. What is not known, however, is how the visual system functions so that color percepts depend upon the integration of ...
Kuriki I - - 1996
Color-constancy mechanisms have been studied and discussed in a number of investigations. However, there has been little attempt to reveal how color constancy deteriorates as the conditions for it become less than optimal. We carried out a series of asymmetric color-matching experiments, using two criteria: surface-color match and apparent-color match. ...
Zuccari A G - - 1996
This article describes the use of a device for assisting in identification of the direction of the arc of rotation while locating the transverse horizontal opening and closing axis of the mandible. Translucent disks are mounted on the point of the styli of a kinematic face-bow and centering magnets are ...
Saito M - - 1996
To measure and compare the main color-preference tendencies in Japan, China, and Indonesia, 490 subjects (175 Japanese, 158 Chinese, and 157 Indonesian) were asked to choose from a color chart the three colors they liked most and the three they liked least and to state the reasons for their choices. ...
Klein C - - 1996
In a delayed matching-to-sample task, the impact of clear or ambiguous go versus clear no-go signals on the post-imperative negative variation (PINV) was examined in 11 patients with a chronic schizophrenic disorder (DSM-III-R) and in a control group of 13 healthy subjects matched to the patient sample by age, sex, ...
Crognale M A - - 1996
The contribution of chromatic mechanisms to motion processing is currently debated. Although OKN as a measure of motion processing has been employed for chromatic stimuli, the contribution of chromatic mechanisms to the production of OKN has not been assessed directly. We measured voluntary-pursuit and involuntary-stare OKN responses to drifting patterns ...
Rabin J C - - 1996
BACKGROUND: Some military aviators have reported difficulty discriminating the color of cockpit warning lights when wearing plastic sunglasses. This difficulty could be due to lenses that are too dark or are nonneutral and thus alter color vision. A study was performed to identify the origin of this problem, recommend solutions, ...
Díaz J A - - 1996
Before a CRT color display is calibrated, the levels of the brightness and contrast controls should be considered. These levels have different effects on the relationship between the chromaticity coordinates of the red-green-blue (RGB) channels and the voltage applied to the gun as well as on the color gamut. Using ...
Moreno I - - 1996
Polychromatic object recognition based on circular whitening preprocessing of red-green-blue components and multichannel matched filtering is described. Computer simulations and experimental results are provided to facilitate recognizing a color target among objects of similar shape but with different color contents. Experimental results are obtained with an optical correlator with two ...
Joseph J E - - 1996
The influence of color as a surface feature versus its influence as stored knowledge in object recognition was assessed. Participants decided whether a briefly presented and masked picture matched a test name. For pictures and words referring to similarly shaped objects, semantic color similarity (SCS) was present when picture and ...
Poirson A B - - 1996
We have studied how contrast threshold sensitivity depends jointly on pattern and color. We measured sensitivity to colored Gabor patches from 0.5 to 8 c/deg. At each spatial frequency, we measured in many different color directions. We analyze the sensitivity measurements using a series of nested models. We conclude that ...
Durgin F H - - 1996
An aftereffect of perceived texture density contingent on the color of a surrounding region is reported. In a series of experiments, participants were adapted, with fixation, to stimuli in which the relative density of two achromatic texture regions was perfectly correlated with the color presented in a surrounding region. Following ...
Jacobs G H - - 1996
The past 15 years have brought much progress in our understanding of several basic features of primate color vision. There has been particular success in cataloging the spectral properties of the cone photopigments found in retinas of a number of primate species and in elucidating the relationship between cone opsin ...
Melgosa M - - 1996
Threshold-discrimination ellipses were obtained by three normal observers, at five color centers, by the use of two experimental devices, which provided light-surface colors, and the same method and experimental conditions. The ellipses obtained for each center in both devices were quite similar when the sample distributions were appropriate and slightly ...
Gegenfurtner K R - - 1996
We investigated the representation of color in cortical area V2 of macaque monkeys, and the association of color with other stimulus attributes. We measured the selectivity of individual V2 neurons for color, motion, and form. Most neurons in V2 were orientation selective, about half of them were selective for color, ...
Macaluso C - - 1996
Chromatic information is carried only by the parvocellular pathway, giving the neurophysiologist the opportunity for eliciting specific responses. Further subdivision of the parvo chromatic system in two opponent chromatic mechanisms is potentially of great interest, given that the anatomical correlate seems to reside in subclasses of parvo ganglion cells that ...
Trusseli H J - - 1996
Digital signal processing tools are used to determine the proper sampling of color spectra and the effect of sampling on the accuracy of derived properties such as CIE tristimulus values and color rendering indexes. It is found that 10 nm sampling is adequate for most applications, but not for more ...
Miller P E - - 1995
Compared with the visual system in human beings, the canine visual system could be considered inferior in such aspects as degree of binocular overlap, color perception, accommodative range, and visual acuity. However, in other aspects of vision, such as ability to function in dim light, rapidity with which the retina ...
Lemon J C - - 1995
The limited service of facial prostheses is the result of degradation of the elastomer and color instability. Deterioration may be caused by many factors, which include environmental exposure and changes in humidity. This investigation assessed the efficacy of an additive, intrinsic, broad-spectrum ultraviolet light absorber on the color stability of ...
Paul S J - - 1995
The final color of all-ceramic restorations is mainly dependent on the light-transmission characteristics of the different components of the ceramic material. This article is a report on the improvement in light reflection and light transmission possible with the new In-Ceram Spinell crown system, which provides a natural-looking appearance.
Kulp T D - - 1995
The Jameson and Hurvich opponent-colors model of hue and saturation was tested for spectral and non-spectral lights. Four observers described the color of lights by scaling hue and saturation. The lights ranged from 440 to 640 nm and consisted of five purities: 1.0, 0.80, 0.60, 0.40 and 0.20. Admixtures of ...
Beatty M W - - 1995
Five dry pigments and one maxillofacial elastomer were evaluated for color changes (delta E) resulting from prolonged exposure to two types of ultraviolet light. The elastomer, pigments, and pigmented elastomers were subjected to each ultraviolet light source for 400, 600, and 1800 hours, and delta E color shifts were determined. ...
Hovis J K - - 1995
Colorimetric analyses were performed in both normal trichromatic and dichromatic color spaces to determine whether several light sources were suitable illuminants for the Farnsworth-Munsell Panel D-15 (D-15) color vision test. Results for fluorescent lamps showed that lamps with a correlated color temperature (CCT) of 7200 degrees K and a general ...
He J C - - 1995
Individual differences in abnormal color vision are well known. A fundamental unresolved problem is the great variation in color vision even among those classified as having the same color-vision defect. Several physiological hypotheses have been proposed to account for this variation but little consideration has been given to how (and ...
Jiménez J R - - 1995
The influence of color signals on stereopsis has been studied using figural-stimuli stereograms with variations introduced according to the opponent chromatic channels (red-green and yellow-blue), derived from Boynton's color-vision model. We used wallpaper stereograms, which enable the rank-order disparity ranges of the chromatic and luminance signals to be compared with ...
Fry G A - - 1995
The spectrum locus on the CIE Chromaticity Diagram represents monochromatic stimuli which have been exposed to a dark adapted fovea. Some of these colors can be made to appear more saturated by chromatic adaptation. The colors both inside the spectrum locus and the supersaturated colors outside are bounded by a ...
Mahon L E - - 1995
BACKGROUND: We considered whether the color discrimination of mild color defectives scoring < or = 100 is the same as that of normals. METHODS: We analyzed the FM 100-hue results of 126 normals and 94 congenital color defectives retrospectively by considering the Total Error Score (TES) and individual cap errors ...
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