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von Campenhausen C - - 1992
Retinal connections causing colors in Benham's top (pattern induced flicker colors, PIFCs) are investigated by psychophysical experiments. PIFCs are still seen when stimuli to different cones are demodulated selectively, indicating the involvement of non-opponent channels. PIFCs also occur on retinal areas next to those affected by modulated stimuli; further, both ...
Muir L E - - 1992
Although Aedes aegypti (L.) are capable of some wavelength discrimination, behavioral experiments demonstrated that color was not a stimulus to which they responded. Optical stimuli that did affect Ae. aegypti behavior were luminous reflectance, vertical contrast, and movement. Stationary objects of low reflectance and solid color were the most attractive ...
Kool F L - - 1992
We have examined the ability of observers to determine the direction of movement of a variety of colored plaid patterns. When the two plaid components are of unequal spatial frequency or of unequal luminance or chromatic contrast, observers judge the direction of movement incorrectly. These errors are correlated with a ...
Njemanze P C - - 1992
Eight normal subjects were examined in dark, light and color conditions. Mean cerebral blood flow velocity (MBFV) were recorded almost simultaneously from their posterior cerebral arteries (PCA) using transcranial Doppler (TCD) ultrasound. The side-to-side difference was significant during the dark (p = 0.0159) and color stimulation (p = 0.0001) but ...
Mullen K T - - 1992
We have tested the behavioral evidence for a separation of the processing of color contrast from motion in the human visual system. Two different aspects of motion perception are examined; the identification of the direction of movement of a chromatic grating and the perception of smooth motion. The results show ...
Kabai P - - 1992
The uptake of tritiated 2-deoxyglucose (2-DG) was examined in brains of artificially selected and unselected control quail, in relation to genetically and environmentally variable early approach preferences of a colored stimulus. The data indicated high labeling in the tectofugal and low labeling in the thalamofugal projection systems in birds exhibiting ...
Abramov I - - 1992
Hue and saturation scaling was used to measure the appearance of spectral lights as a function of stimulus size at loci spaced across the horizontal meridian. At a given locus, each hue (red, yellow, green, and blue) grew as a function of stimulus size to some asymptotic value. Growth functions ...
Skon J - - 1992
In previous studies photographic projections containing only mixtures of red and white light produced a wide variety of hues. In the present experiment similar patterns were produced on a color monitor. Squares with four combinations of red and white light were studied at two mean luminances. Subjects reported that a ...
Kooi F L - - 1992
The effect of several new stimulus parameters on the perception of a moving plaid pattern (the sum of two sine-wave gratings) were tested. It was found that: (i) the degree of perceived sliding is strongly influenced by the aperture configuration through which the plaid is viewed; (ii) the chromaticity of ...
Deguchi T - - 1992
The present study was designed to investigate the effects of color temperature of lighting sources on a contingent negative variation (CNV). Eleven male students (mean age, 23.2) volunteered as subjects. The CNV was recorded under three different color temperature conditions (3000 degrees K, 5000 degrees K and 7500 degrees K). ...
Takeichi H - - 1992
Two aspects of neon color spreading, local color spreading (neon flank) and illusory contour, were investigated by dichoptic viewing. Neon flank was not observed under appropriate dichoptic stimulation, suggesting that input to the process for local color spreading is based on monocular configuration. However, illusory contours were formed according to ...
Rock I - - 1992
It is widely acknowledged that a precondition for the perception of the world of objects and events is an early process of organization, and it has generally been assumed that such organization is based on the Gestalt laws of grouping. However, the stage at which such grouping occurs, whether early ...
Raasch T W - - 1991
A limited set of illuminants and phosphor colors are commonly used in video display terminal (VDT) working environments. This study attempts to identify any combinations of such conditions that influence performance on a visually demanding counting task. Experiments were performed to test whether the phosphor color, ambient lighting spectrum, or ...
Grigsby S S - - 1991
Spearman rank-order correlations (R) were made between the color-mixture threshold, spatial contrast sensitivity, and flicker sensitivity measurements of 38 patients with a variety of optic nerve disorders. Patients had to satisfy the following criteria: greater than 0.5 log unit loss of chromatic or achromatic sensitivity (compared to age-matched normals), central ...
Ghiradella H - - 1991
All butterfly and moth scales share the same basic architecture, but various elements of this architecture are particularly complex in those scales that exhibit structural colors. These elements include the scales' ridges and their associated lamellae and microribs, and the trabeculae, the pillars normally that act as spacers within scales. ...
Bohren C F - - 1991
Colors in birefringent airplane windows seen through polarizing filters are not especially pure nor are all colors equally probable. This is a consequence of the shape of transmission vs wavelength for a retarder-polarizer combination illuminated by partially polarized skylight. Although transmission can have a single peak in the blue or ...
Theeuwes J - - 1991
Three visual search experiments tested whether top-down selectivity toward particular stimulus dimensions is possible during preattentive parallel search. Subjects viewed multielement displays in which two salient items, each unique in a different dimension--that is, color and intensity (Experiment 1) or color and form (Experiments 2 and 3)--were simultaneously present. One ...
Bundesen C - - 1991
Nissen (1985) compared selection by location with selection by color or shape in partial-report experiments. Her analysis of response contingencies when a target was defined in terms of one attribute (location, color, or shape), and when the task was to report the two remaining attributes, suggested a special role for ...
Guth S L - - 1991
A multizone color model is described. It has nonlinear receptor gain control, two postreceptor opponent-colors processing stages, and neural compression late in the visual pathway. It is assumed that gain control can be activated by receptor responses from a test light itself (self-adaptation) and (or) by receptor responses from other ...
Dunwoody L - - 1991
Color can influence physical and emotional variables, but the evidence is equivocal. Replications are often hampered by inadequate specification of colored stimuli. It is proposed that a standardized method for reporting colored stimuli should be employed to facilitate empirical testing of the effects of color, namely, the CIE chromaticity coordinates ...
Van Toi V - - 1991
The flicker sensitivity of the human eye may be characterized by the De Lange curve (temporal modulation transfer function plot). In the curves of two out of eight observers, D. H. Kelly [J. Opt. Soc. Am. 52,940-947 (1962)] found three peaks instead of one, as had been reported in previous ...
Luria S M - - 1991
Subjects matched the color of a vertical target line, presented in 1 of 10 colors, to a set of 10 colors. The target line was presented either in isolation or together with 5 additional colored lines. Neither mean reaction time nor the number of matching errors increased when the extraneous ...
Adams R J - - 1991
Several photoreceptoral and neural models have been proposed to account for the development of human vision. To further evaluate those applicable to color vision, the present study examined 40 neonates' (mean age = 3.2 days) chromatic-achromatic discriminations in the mid-spectral region by using an habituation procedure and measures to minimize ...
Sharpe L T - - 1991
A randomly dotted yellow disk was rotated at a speed of 5 rpm, alternating in direction every 10 sec. Its change in direction of rotation was paired with a change in surround color, which was either red or green. After 15 min of exposure, observers reported vivid motion aftereffects contingent ...
Ye S P - - 1991
A simple video position-digitizer has been developed for studying the movement patterns of small animals. This report provides a complete procedure for constructing the circuit, which when used in conjunction with a conventional video camera and an IBM PC compatible computer, automatically digitizes and records the path of a dark ...
Abramov I - - 1991
Hue and saturation scaling were used to measure the appearance of spectral lights as a function of stimulus size for nine loci across the horizontal retinal meridian. At a given locus, each hue (R, Y, G, and B) grew as a function of stimulus size up to some asymptotic value. ...
Neumeyer C - - 1991
Spectral sensitivity was measured under different adaptation levels using a behavioral training technique in which the fish had to discriminate between a dark test field and a test field illuminated with monochromatic light. Depending on which of the two test fields was used as training test field, two functions were ...
Cavanagh P - - 1991
By opposing drifting luminance and color gratings, we have measured the "equivalent luminance contrast" of color, the contribution that color makes to motion. We found that this equivalent contrast was highest (greater than 10%) for low spatial and temporal frequencies and was higher for red/green than for blue/yellow stimuli. Equivalent ...
Endler J A - - 1991
Color patterns of natural populations of guppies (Poecilia reticulata) are a compromise between sexual selection and predation avoidance. Field data on ambient light spectra, water transmission spectra, courtship and attack distances, and cone pigments of guppies and their predators were used to calculate measures of conspicuousness of guppies under various ...
Courtney S M - - 1991
We propose a model of temporal signal processing within the retina based on temporal differences between the color pathways which may explain the phenomenon of subjective color. We quantify the model by inferring impulse response functions from physiological data, and predict the output of the different color pathways to temporally ...
Papathomas T V - - 1991
Starting with the experiments of Ramachandran and Gregory (Nature, 275, 55-56, 1978), several psychophysical studies in apparent motion (AM) have established that the perception of motion is significantly impaired at equiluminance. Still debated, however, is whether color alone can resolve ambiguities in AM. We report here on several psychophysical experiments, ...
D'Zmura M - - 1991
Colored targets pop out of displays under conditions in which the standard red-green, yellow-blue and black-white mechanisms cannot directly mediate detection. Experimental evidence suggests that observers possess chromatic detection mechanisms tuned to intermediate hues such as orange as well as to hues characterizing the standard color-opponent mechanisms and that these ...
Honig W K - - 1991
In 5 experiments, pigeons learned to discriminate uniform arrays of colored elements from mixed arrays containing 2 colors in various proportions. When only the uniform arrays were positive, mixture-negative gradients were obtained. When only the arrays containing equal numbers of red and blue elements were positive, mixture-positive gradients were obtained. ...
Schiller P H - - 1991
It has been proposed that the functions of the two major parallel channels of the primate visual system, the color-opponent and the broad-band, can be determined in psychophysical experiments by eliminating luminance but maintaining chrominance information (isoluminance), since under such conditions the broad-band channel is believed to be silenced. To ...
Spekreijse H - - 1991
To answer the question whether, like man, ethambutol treated fish would become color-blind, wavelength discrimination was measured behaviorally in goldfish, preceding, during and after ethambutol treatment. The results are that of the three high discrimination abilities at around 400, 500 and 600 nm, ethambutol affected the latter one. Red-green discrimination ...
Chaudhuri A - - 1990
Current approaches to the problem of equating different colors for luminance (chromatic isoluminance) rely upon human reports of perceptual events that are reduced at some luminance ratio. In this report, a technique is described that evokes a vivid percept of motion of a textured pattern only at isoluminance. Furthermore, in ...
Wolfe J M - - 1990
In visual search for a conjunction it is much more difficult to search for the conjunction of 2 colors or 2 orientations than for Color x Orientation or Color x Shape conjunctions. The result is not limited to particular colors or shapes. Two colors cannot occupy the same spatial location ...
Solomon S S - - 1990
Fire departments have long used red as the traditional color for fire apparatus and have been reluctant to change. Optometric research and literature offers ample proof that red is a poorly detected color. This paper views the shortcomings of red. Simultaneously, it reports that the ancillary equipment and markings used ...
Schiller P H - - 1990
The functions of the primate color-opponent and broad-band channels were assessed by examining the visual capacities of rhesus monkeys following selective lesions of parvocellular and magnocellular lateral geniculate nucleus, which respectively relay these two channels to the cortex. Parvocellular lesions impaired color vision, high spatial-frequency form vision, and fine stereopsis. ...
Schein S J - - 1990
Spectral properties of 129 cells in the V4 area of 5 macaque monkeys were studied quantitatively with narrow-band and broad-band colored lights. The large majority of cells exhibited some degree of wavelength sensitivity within their receptive fields. The half-bandwidth of the primary peak in the spectral-response curve was less than ...
Nagy A L - - 1990
Color differences required for fast parallel searches were measured for small and large display fields. The main purpose of the measurement was to test the hypothesis that serial searches obtained with small color differences in large display fields are due to poor discrimination in the peripheral visual field and to ...
Creutzfeldt O - - 1990
It has been suggested that object colors in a colored environment are the result of combining in perception the (relative) brightness of each spectral component rather than of just mixing the spectral luminances. We tested this hypothesis with the following experiment: A pair of center-surround targets made of colored papers ...
Drum B - - 1990
Vector models of color vision predict that the chromatic saturation of near-threshold incremental stimuli should grow with increasing achromatic adaptation. In contrast, colorimetric models predict that saturation should decrease with increasing adaptation in correspondence with excitation purity. An experimental test disagrees with both predictions, but is consistent with a two-process ...
Peutzfeldt A - - 1990
The color stability of three composite resins used in the inlay/onlay technique was determined by means of irradiation with UV-light and by water storage. Generally, water storage resulted in greater changes in color than did UV-light, but no correlation was found between the results of the two chromogenic procedures. The ...
Pastoor S - - 1990
This study examined legibility performance and subjective preference for text/background color combinations displayed on a video monitor. Luminance contrast was fixed at two preoptimized levels, either with text brighter than the background (10:1) or vice versa (1:6.5). In Experiment 1, 32 subjects rated about 800 color combinations. No evidence suggested ...
Travis D S - - 1990
We have investigated the effects of chromatic and luminance contrast on reading colored text on multicolor displays. Stimuli were defined in a color space with three cardinal axes. Two of these axes are chromatic and maximally modulate the opponent mechanisms of color vision; the third is an achromatic axis. We ...
Mullen K T - - 1990
The experiments that we report aim to elucidate the linkage between cone outputs and color sensation. This is investigated by measuring wavelength discrimination between stimuli at threshold levels of detection. Stimuli are large spots (0.75 deg) presented on a white background. A 2 x 2 alternate forced choice method is ...
Neitz J - - 1990
Earlier we reported that Rayleigh matches made by males with normal color vision fall into distinct groups, and proposed that this behavior reflects an X-chromosome linked polymorphism in the spectral positioning of cone pigments (Neitz & Jacobs, 1986). In the present experiments two different color matches were obtained from each ...
Stone M A - - 1990
The design of a physician's office can affect whether patients return, follow advice, or recommend the physician to other people. Color is an important element in design. It can make people relaxed or excited; it can help or hinder vision. Decreased color perception and differentiation occurs with increased age. In ...
Boynton R M - - 1990
Using single color terms of their choice, nine subjects named each of 424 colors twice under carefully-controlled conditions. Compared to any other color names, the chromatic basic color terms (red, green, yellow, blue, orange, purple, brown and pink) are all used more consistently within subjects, with greater consensus between subjects, ...
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