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Wilson A - - 1981
Transient visual-evoked cortical potentials (VECP's) were recorded for equal luminance chromatic flashes presented against a dark background and for substitutions of chromatic stimuli for achromatic fields of equal luminance. The VECP's for the flashed targets had larger amplitudes and shorter latencies than those for the substituted targets. These findings are ...
Bowman K J - - 1981
Navigation lights are a set of color-coded signals intended to indicate the presence, orientation, and relative direction of aircraft at night, and thereby reduce the possibility of midair collisions. It is known that some people with defective color vision have difficulty with quite simple codes. Accordingly, the International Civil Aviation ...
Meyer G E - - 1981
Past research based on the McCollough effect and efficacy of chromatic cues in stereopsis suggests that color information is difficult to process binocularly as compared to form information. This study evaluates this proposition using a reaction time paradigm. Subjects decided whether two simultaneous visual stimuli were the same in shape ...
Barna G J - - 1981
A study was undertaken to evaluate the influence of light intensity on the ability to discriminate color differences within the color range of natural teeth. The results show that shade selection is not significantly affected within the range of 75 to 300 fc. Neither the specialty of the dentist nor ...
Breton M E - - 1981
Two observers were classified as deuteranopes by standard tests including two-degree anomaloscope matches. Color matching similar to the Rayleigh type was then carried out for a 10-degree field size at retinal illuminance ranging from 1 to more than 3000 trolands (td). The results show that at the larger field size ...
Neeley W E - - 1981
A new instrument was conceived and designed for quantitative measurement of chromophoric areas or colored spots such as are produced in (e.g.) thin-layer chromatography. The areas to be measured are subdivided grid-like into small subunits, and the absorbance of each of these is measured. The sum of absorbances for all ...
Fry G A - - 1981
The Ives effect is the discrepancy between photometric matches made by direct comparison and those made by flicker. When white is used as a standard stimulus, the discrepancy appears to be related to the saturation of the test stimulus. The two methods of photometry involve differences in adaptation. In flicker, ...
Gerhart G - - 1981
A technique is presented for color encoding holographic interferometric fringe patterns using an extended white-light source. The color encoding is performed on the smeared Fourier spectra which are derived from an on-focus multiplexed interferometric hologram. This color encoding technique offers the advantages of direct comparison of different fringe patterns which ...
Gelineau E P - - 1981
A three-part investigation was conducted to explore the meaning of color preferences. Phase 1 used a Q-sort technique to assess intra-individual stability of preferences over 5 wk. Phase 2 used principal components analysis to discern the manner in which preferences were being made. Phase 3 used canonical correlation to evaluate ...
Costas R R - - 1981
The association of skin color with coronary heart disease risk factors was studied in 4,000 urban Puerto Rican men. Skin color on the inner upper arm was classified according to the von Luschan color tiles. Using this grading, men were separated into two groups of light or dark skin color. ...
Carter E C - - 1981
The principle that things are easier to find if they contrast with their environment is expressed quantitatively. Two indices of conspicuousness, relative fixation rate and search time, are shown to be related to the color difference between the target and background objects. The color difference equations used are CIELAB, CIELUV, ...
Fischer G J - - 1981
Color pecking preferences in day-old, dark-hatched domestic chicks of 2 breeds were studied as a function of (1) target luminance (dim, medium, or bright) when testing was in darkness and in the light (Experiments I and II): (2) method of equilibrating target brightnesses (i.e., objectively or subjectively: Experiments III and ...
Ebenhöh H - - 1981
Saturation and hue perceived in monochromatic stimuli and in light mixtures were scaled psychophysically by a direct magnitude estimation method. The colors were of aperture mode and were presented against a dark background. As a result opponent-colors functions were obtained which show the hue sensations produced by the lights of ...
Saunders D R - - 1980
It is proposed that the best measure of individual Stroop interference is the logarithm of the ratio between time to read the interference card and time to read the pure color card, i.e., logs(C/B). A review of the literature shows a very close correlation across studies between Stroop interference so-defined ...
Bailey J E - - 1980
Pathology of the visual system can alter perception in the central and peripheral visual field. Pseudoisochromatic plates and pigment panel tests can be used to study macular color vision. Perimetric techniques using color targets extends testing to the peripheral field. This facilitates detection of early, sometimes subtle defects that are ...
Yu F T - - 1980
A real-time white light pseudocolor encoding technique for spatial frequency and density encodings is presented. In spatial frequency color coding, the encoding is accomplished by spatial filtering of the color signal spectra, while in density pseudocoloring, the encoding consists of contrast reversal of a color object image. The technique is ...
Silberglied R E - - 1980
Experimental obliteration of high-contrast wing stripes of the neotropical butterfly Anartia fatima affected neither survival nor wing damage in a natural population over a 5-month period. There is no direct evidence supporting the hypothesis that so-called disruptive wing patterns function as protective coloration in butterflies.
Young R E - - 1980
Two species of mesopelagic squid greatly altered the color of their bio-luminescence during counterillumination. The color change was triggered by changes in water temperature corresponding to those normally encountered by these vertically migrating animals. These squid can probably conceal themselves under the different colors of downwelling light that they encounter ...
Pratt F - - 1980
The brightness of colors in a number of paintings by Francis Pratt appeared to vary as a function of the viewing distance. These pictures were composed of narrow strips of different colors varying in brightness and saturation. Five experiments were undertaken to replicate and study this effect under controlled conditions ...
Spiegler J B - - 1980
The usual (geometric) procedure to determine the chromaticity coordinates of a color that results from the additive mixture of colored stimuli is to plot the coordinates of these stimuli on the CIE chromaticity diagram and apply the center-of-gravity rule. This procedure, however, may become inaccurate and cumbersome if more than ...
Maguire W M - - 1980
After viewing red vertical stripes and green horizontal stripes, the eye subsequently views white vertical stripes as greenish and white horizontal stripes as pinkish. It has been theorized that this phenomenon, known as the McCollough effect, is related to long-tern adaptation of cells tuned for both color and orientation. Such ...
Fry G A - - 1980
A bipartite stimulus 2 degrees in diameter was used to study the Bezold-Brücke phenomenon for purple colors. A mixture of 460 nm and 667 nm in one half at a given luminance was matched with a mixture of the same two wavelengths at a luminance level 10 times higher. The ...
Kong K L - - 1980
The compound eye of the grasshopper Phlaeoba has alternating bands that appear clear or brown. Electroretinograms recorded from the individual bands have different action spectra: The spectrum of the clear band peaks at 525 nanometers and that of the brown band at 545 nanometers. Spectrally selective whole-eye adaptation with light ...
Guth S L - - 1980
The inclusion of cone mechanisms in a slightly revised version of an earlier model allows accounts of phenomena that involve receptor effects as well as dichromatic color vision. Intensity-dependent parameters that stimulate the adaptation of receptors and opponent and nonopponent mechanisms are varied to predict a wide range of data ...
Kovach J K - - 1980
Visual preferences were studied in 18,225 quail chicks (Coturnix coturnix japonica) of three genetic populations, in relation to 185 pairs of systematically varied and combined flash rates, flash amplitudes, luminances, and colors. Results indicate additive and nonadditive interactions between preference values of stimulus elements embedded in complex stimulus information. Flicker ...
Honjyo K - - 1979
Reference and test stimuli were produced on two separate color television screens to evaluate the color discrimination ability of the human eye for near-white colors. Each test stimulus had a luminance approximately equal to that of the reference, but was slightly different in chromaticity, e.g., [deltax] less than 0.01, [deltay] ...
Kubota T - - 1979
Experimental techniques are described for recording Lippmann color holograms in methylene-blue-sensitized dichromated gelatin. 458-, 488-, and 514.5-nm light from an argon laser and 633-nm light from a He-Ne laser are used to record the holograms. Data on the diffraction efficiency and wavelength selectivity are presented.
Nagy A L - - 1979
A color-naming method was used to examine the large-field red/green discriminations of dichromats screened with standard tests. The stimulus was a 12 degrees annular field with the central 4 degrees removed, flashed for 300 ms. Four wavelengths were equated in brightness for each observer at two retinal illuminance levels, approximately ...
Gouras P - - 1979
Color-opponent ganglion cells in the monkey retina respond to luminance flicker at high temporal frequencies. Color opponency, which makes these cells so selective of wavelength at low temporal frequencies, is progressively lost at high frequencies. This loss is due to a frequency-dependent phase shift between the responses of spectrally different ...
Valenzeno D P - - 1979
Ignorance of phototoxicity by the general biomedical community constitutes a health hazard. Certain food colorants and dyes proposed for use in angiography produce lethal effects in cells and whole organisms on light exposure but not in the dark. Yet-light-relatedness is usually neglected in toxicity studies. We urge that the specific ...
Nissen M J - - 1979
The investigation of visual processing mediated solely by chromatic information requires conditions preventing a subject's use of the luminance differences normally accompanying a chromatic change. In Experiment 1, which involved a discriminative reaction time (RT) task, chromatic and white stimuli of the same luminance were presented on a dimmer achromatic ...
Fernandez B Q - - 1979
The purpose of the present study was to determine discrimination learning rates as a function of the nature of the stimulus and the relevant dimension. Ss were 160 preschool boys and girls. The design consisted of two stimuli (faces and cups), two constant dimensions (size and form), and two relevant ...
Fields L - - 1979
After establishing discrimination between a red positive stimulus and a green negative stimulus, the lowest intensity colors that restricted all responding to the positive stimulus were determined. Then, two new white lines differing in terms of line orientation were each superimposed on one of the colors and were increased in ...
High R W - - 1979
Eight adult male subjects participated in a counterbalanced, repeated-measures design to determine the relative efficacy of color and black-and-white visual sexual stimuli in eliciting sexual arousing, as objectively measured by a mercury-in-rubber strain gauge transducer. There were no consistent or significant differences in either the intensity of the pattern of ...
Ikeda M - - 1979
When two lights of different wavelengths are dichoptically presented to the eyes to form a single visual field, the fusion of colors cannot be assured unless the difference is relatively small. The limit of the wavelength difference delta lambda beyond which no homogeneous color is obtained was determined for the ...
Woo G C - - 1979
Three subjective determinations of the reading addition required by each of 10 subjects were obtained in this study with the use of a cross cylinder grid target, a variable color, near-point, grid target and an ordinary reading card. All three methods gave similar results. In addition, there was no change ...
Kinney J A - - 1979
Measures were made of the ability of color-defective men to judge correctly the colors of navigation lights (red, green, or white) presented to them at night under realistic sea conditions. Eighty-one color-defective men were employed; they were categorized as to type and degree of defect using a battery of five ...
Hoyenga K B - - 1979
The effects of stimulus color and gender upon the perception of an afterimage were examined. The Ss were 32 male and 32 female college undergraduate volunteers. Eight Ss of each gender viewed a pinpoint flash of light through one of four filters: blue-green (Wratten 44A), red (Wratten 92), yellow (Wratten ...
Kinameri K - - 1979
A minicomputer controlled scanning colorimeter has been developed, which automatically measures the distribution of chromaticity coordinates over the phosphor screen of a color picture tube. After measurement, the distribution of chromaticity difference vectors is displayed immediately on a CRT screen. Mean color difference is calculated for all points measured. This ...
McCarter A - - 1979
The chromatic Hermann grid illusion was investigated in sixteen subjects, with variation of the lightness contrast between the chromatic inducing squares and the background, and the saturation and hue of the inducing squares. Subjects made magnitude estimates of the sharpness and clarity of perceived dots at the intersections of the ...
Harker D - - 1978
Combinations of translations and color permutations are derived that leave a periodic array of colored points-a colored lattice-apparently unchanged. It is found that there are three types of colored lattices: (1) those in which all rows and nets have more than one color, (2) those in which there are rows ...
Bird J F - - 1978
The elements of vision are brightness and color varying in time and space, constituting a vector space-time function: the visual sensation field. The sensory-field generated from the light-field variations on the retina is analyzed here in terms of elemental space-time responses (Green's functions). Both chromaticity and intensity variations in either ...
Tai A - - 1978
A simple technique utilizing a white-light processing system for the pseudocolor encoding of photographic materials by density is presented. Pseudocolored output of many different color codes is obtained by selectively spatial filtering the dispersed colors of the various high-diffraction orders of a halftone input. Besides permitting a large variety of ...
Luyten W J - - 1978
An analysis has been made for solar motion for 128 very faint white dwarfs of color class b or a. While about 40% of these stars may be high-velocity objects, it seems definitely indicated that the luminosity of all of them is considerably lower than that for the "normal" white ...
Hemenway K - - 1978
The hypothesis that perceived dimensionality of projection drawings is influenced by perceived organization was tested in two experiments. Organization was biased by coloration: The drawings were (a) uncolored, (b) colored in ways that emphasized plausible three-dimensional parts of the represented objects, or (c) colored in ways that emphasized two-dimensional (2D) ...
Fields L - - 1978
A successive discrimination between red positive and green negative stimuli was established with pigeon subjects. Then, lines with different angular orientations were superimposed on one of the colors to form compound stimuli. Finally, either the colored element of the positive compound, the colored element of the negative compound, or both ...
Plass G N - - 1978
The color of the ocean is calculated from a model that realistically takes into account the various types of scattering and absorption events that occur in both the atmosphere and ocean. Solar photons are followed through the atmosphere and into the ocean by a Monte Carlo technique. The reflection and ...
Charman W N - - 1978
Previous studies of the effects of color on the accommodation response are reviewed. The monocular, steady-state response to targets under various colors of illumination is investigated. It is shown that trained observers change their level of accommodation, when viewing a target at a constant distance, to compensate for the varying ...
Gunkel R D - - 1978
A simple and informative method is described for determining the type and extent of color defects. The subjects' responses are registered automatically on a chromaticity diagram that is based on the newtonian model. Color defects are readily identifiable by a skewing of the normal central gray area toward the defectively ...
Greenhouse D S - - 1978
The detectability of a brief color shift towards red or towards green of a foveally viewed yellow target is less by 25% if the observer is uncertain as to the direction of the color shift. This result matches a prediction of the theory of signal detectability: When signal parameters become ...
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