Hue naming: A test of the validity of Werner and Wooten’s average observer

Fifteen subjects scaled monochromatic lights ranging from 460 to 640 nm by assigning percentages to the names blue, green, yellow, and red, representing the proportion of these hues perceived in the lights. The resulting hue-naming functions were compared to those predicted from the opponent-chromatic response functions of Werner and Wooten’s (1979b) proposed average observer. The agreement between the two sets of functions was reasonably good, which strengthens the validity of their average observer.     

Infants are trichromats.

Two experiments were conducted to demonstrate that human infants 3 months of age perceive color in a normal, trichromatic manner. In the first experiment, the visual attention of 30 infants was monitored in a habituation-dishabituation paradigm that used spectral and white lights with brightness factors eliminated. Infants discriminated white from monochromatic light in a region of the spectrum (490–500 nm) where color-normal adults can but color-deficient adults cannot. In the second experiment which also used a habituation paradigm, eight infants showed good discrimination between hues in a region of the spectrum (560–580 nm) where color-deficient adults typically show no hue discrimination. Results from these studies of the neutral zone and hue discrimination evidence trichromatic vision in infancy and are discussed in the context of their several clinical, social, and intellectual implications.     

The pigeon's perception of saturation.

Three experiments used similar methods to investigate the pigeon's perception of saturation of monochromatic lights. This trial-wise procedure consisted of brief presentations of positive and negative stimuli in random sequence. Pecks to the positive stimuli were occasionally reinforced on a low fixed-ratio schedule. The first study determined absolute thresholds for "white" and monochromatic lights by establishing a discrimination between lights of various radiances and a dark key. Experiment II investigated generalization from a white light to various monochromatic lights under conditions that minimized the use of luminance as a cue. The third experiment examined discrimination of various monochromatic lights along a colorimetric purity continuum; responses to white light were reinforced, while responses to lights that combined white and monochromatic lights in various proportions were not. The results indicated that lights of different wavelength differ in saturation, but that all are discriminable from white. Wavelengths between 550 and 600 nm are least saturated for the pigeon, and saturation increases markedly as wavelength decreases below this region of the spectrum.     

Delayed monochromatic hue matches indicate characteristics of visual memory

Short-term memory for 16 monochromatic hues from 425 to 640 nm was measured after six delays from .1 to 24.3 sec by means of an iterative, momentary stimulus-matching technique. Small shifts were revealed in the remembered hue produced by certain wavelengths at some delays. These shifts did not follow trends consistent with a storage dependent on sensory pathway characteristics, perceptually unique hues, or semantic encoding but may reflect entropic effects in a storage that is remarkably unbiased. By indicating the discriminability of hues in memory, standard deviations of the delayed matches reveal other characteristics of what is stored: Their smooth, exponential growth questions the existence of "levels" and permits estimating the half-life of hue memory; their continued resemblance to the discrimination function for simultaneously perceived hues suggests that the stored activity; closely resembled the sensory response of color. The results also indicate how successive comparisons may be corrected in applied color work.     

明视条件下人眼对低频间断光的亮度感觉

本实验是以异色亮度匹配方法,探索视觉系统对在明视觉水平上的低频、不同时间调制的单色光和白光的亮度感觉特性。结果发现,闪光刺激在临界频率以上作用于视觉系统所产生的亮度感觉是遵循塔耳玻特-普拉托定律。而对在临界频率以下亮暗比为4/1的间断单色光刺激所需的周期平均亮度低于恒定单色光所需的亮度幅度,这表明塔耳玻特(Talbort)定律不适用于低频、高亮暗比的间断单色光。仅适用于间断单色光刺激的亮暗比低于1,波长为650纳米的间断单色光。     

Psychophysical saturation scales and the spectral sensitivity in human vision

Summary For mixtures of white and colored lights, the intensity of the colored light necessary to produce a linear psychophysical saturation curve is determined. This intensity may be defined as equilibrium between chromatic and achromatic excitation. From a measurement of the equilibrium throughout the spectrum, a spectral sensitivity function may be derived. According to the hypothesis of Börsken and Hemminger (1980), this function describes the spectral sensitivity of the achromatic channel in human color vision.     

Spectral sensitivity of the Sooty mangabey

Purkinje shift and scotopic and photopic spectral sensitivity functions were determined for four Sooty mangabeys and five human controls using a flicker technique in a four-choice discrete trials task. Results-indicate a Purkinje shift similar in magnitude and frequency locus to that of human controls. Scotopic spectral sensitivity was almost identical to that of human controls, although both species showed reduced sensitivity relative to the standard CIE function, -at short wavelengths. Photopic spectral sensitivity disclosed enhanced sensitivity in the blue and reduced sensitivity (0.3–0.4 log units) in the red relative to human controls.     

Qualities of color vision in infancy.

Four-month-old infants attended differentially to eight equally bright, monochromatic spectral lights; that is, they discriminated colors. Moreover, infants showed the same pattern of differential attention regardless of experimental group (different groups of infants saw different subsets of all possible pairings of colors) or experimental method (paired comparisons or single stimulus). In general, the differential attention of infants to colors parallels the ratings of the pleasantness of those same colors by adults. Finally, infants looked significantly longer at color category centers than at color category boundaries. These results suggest that looking at this early stage of infancy can better be understood in terms of preference rather than in terms of stimulus categorization. The results also provide further evidence for a neural excitation model of early visual attention.     

Comparison of changes in sensitivity and sensation: implications for the response-intensity function of the human photopic system

Brightness magnitude estimations of foveally presented flashes deviate from a power function. Increment threshold functions for test lights presented upon these same flashes deviate drastically from a constant Weber fraction. These departures from the classic laws of sensation and sensitivity are shown to be in qualitative agreement and to be affected in similar ways by changes in steady adapting fields. Both sets of data can be fit over the lower range of flash intensities by models based on a saturating response function; both sets deviate from these models at high flash intensities in ways consistent with a nonsaturating response function.     

Reexamination of spectral mechanisms in the rat (Rattus norvegicus)

The spectral mechanisms of the rat were studied in electrophysiological and behavioral experiments. The photopic electroretinogram (ERG) was recorded (a) to rapidly flickering lights, (b) during the cone phase of dark adaptation, and (c) with a flicker photometric procedure. Each procedure indicated the presence of a single cone mechanism having a lambda max of about 510 nm. Increment-threshold spectral sensitivity functions measured in a behavioral test situation yielded the same conclusion. A behavioral experiment failed to produce any evidence for the presence of color vision in this rodent. The consistent conclusion from both behavioral and electrophysiological experiments is that the rat retina contains only a single photopic spectral mechanism.     

Verbal reaction times to hues vs hue names and forms vs form names

Iwo choice reaction time (RI) studies were carried out in which different classes of stimuli—hues vs hue names in one study and forms vs form names in the other—occurred in independent lists of2, 4, and6 equally probable alternatives. Mean choice RIs were faster for hue names and form names than for hues and forms with4 and6 alternatives, but no significant differences were found in the2-stimulus lists. In both studies, significant list length by stimulus type (e.g., hues vs hue names) interactions indicated greater increase in mean RI with increases in list length for forms and hues than for form names and hue names. It was concluded that differential amounts of generalization of interference aceounted for the interactions. Effects of experimental variables on inferred components of RI were also examined.     

Scotopic contrast hues displaced toward red

Stabell, B. & Stabell, U. Scotopic contrast hues displaced toward red. Scand. J. Psychol., 1973, 14, 316–319.-The displacement of scotopic contrast hues toward red, contrary to predictions based on the opponent color theory of Hering, is explained on the assumption that the violet receptor system has a negligible sensitivity at the yellow cardinal point, while all the receptor systems are activated at the blue cardinal point.     

Emotion regulation difficulties in anorexia nervosa: Relationship to self-perceived sensory sensitivity

Changes in sensation (e.g., prickly skin) are crucial constituents of emotional experience, and the intensity of perceived changes has been linked to emotional intensity and dysregulation. The current study examined the relationship between sensory sensitivity and emotion regulation among adults with anorexia nervosa (AN), a disorder characterised by disturbance in the experience of the body. Twenty-one individuals with AN, 20 individuals with AN who were weight–restored, and 23 typical controls completed self-report measures of sensory sensitivity and emotion regulation. AN participants reported heightened sensory sensitivity and greater difficulty regulating emotions relative to controls. Self-perceived sensory sensitivity was associated with greater emotion dysregulation. Weight-restored AN participants reported greater ability to regulate emotions than their currently underweight counterparts, despite heightened sensitivity. Findings suggest that hypersensitivity may be a persisting feature in AN, and that weight restoration may involve improved ability to cope with sensation.     

Wavelength effects on simple reaction time

Simple reaction time was measured to spectral lights matched photometrically in luminance. When these lights were presented on a dimmer achromatic background, reaction time did not vary as a function of wavelength. Moreover, reaction times to white and chromatic lights were the same. When the luminance of the background was the same as that of the chromatic lights, reaction time increased and showed a strong effect of wavelength. Reaction time in this condition appeared to follow a saturation function. The results are described in terms of the operation of achromatic and chromatic processing channels.     

The use of visual and name codes in scanning and classifying colors

The effect of incongruent color words on speed of classifying ink colors was measured in visual scanning tasks and in card sorting tasks. In both cases, little or no interference effects were noted when the classification allowed focusing on a single ink color or a set of highly similar colors (adjacent hues). Substantial interference occurred when the task required grouping of three dissimilar colors (nonadjacent hues). These findings suggest that the relative efficiency of name and visual codes in making perceptual classifications is largely dependent upon the memory requirements imposed by the task.     

Equal-onset contours of vibrotactile stimuli

Characteristic sensations of “surge” occur at onset of vibratory stimulation, analogous to the experience of musical “attack” in the auditory modality. Such a cutaneous sensation may have a phenomenal reality that is discriminable from the sensitivity to either of its physical determinants of time and intensity. Contours of equal-onset sensation obtained by the method of adjustment permitted the assessment of the relative contributions of these two parameters. Both rise time and intensity were found to be significant factors in the determination of contours of equal-onset sensation obtained by either time adjustment or adjustment of vibratory intensity. Equating onset by intensity adjustment was found to be more difficult than equating onset by time adjustment.     

Multidimensional scaling of color difference in the pigeon

Pigeons were required to discriminate between “identical” vs “different” pairs of lights in a yes/no signal-detection task with a symmetrical payoff matrix. If the two lights projected on the two halves of the bipartite field constituting the center response key in a three-key chamber were identical in wavelength composition, a single peck on the right key was reinforced with food. If the two lights differed in wavelength composition, then left-key pecks were reinforced. In Experiment 1, each of six pigeons experienced all possible pairs of 11 spectral lights and 1 purple light (66 pairs). In Experiment 2, the set of lights was expanded to 15 (105 pairs) and included a white light. The percentage of correct choices was taken as an index of the dissimilarity between the two lights constituting a pair. The rank-order information available in these dissimilarity measures was used to determine coordinate projections for each light in a two-dimensional Euclidean space. The configuration obtained in this manner was interpreted as a color circle for the pigeon.     

Colour changes as a function of luminance contrast.

When spectral light increases in luminance, the hues change. Normally, long-wavelength light becomes increasingly yellow, and short-wavelength light turns blue or blue-green. This is known as the Bezold-Brücke hue shift. Less notice has been paid to the change in relative chromatic content (saturation or chromatic strength) that accompanies these shifts in hue. As luminance contrast increases from zero, chromatic strength increases to reach a maximum at a luminance that is wavelength dependent. Short-wavelength blueish light reaches this maximum at low relative luminances, whereas midspectral yellowish stimuli need several log units higher luminance. Red and green are somewhere in between. For luminances above this maximum, the chromatic content usually diminishes, and most light becomes more whitish in appearance. In this study it is demonstrated how the combined chromatic appearance of hue and chromatic strength change with intensity. Both phenomena find a common physiological interpretation in the nonlinear and nonmonotonic responses of colour-opponent P cells in the retina and lateral geniculate nucleus of the primate. A model that combines the outputs of six P-cell types accounts for observers' estimates of hue and chromatic strength.     

The diagnosticity of color for emotional objects

Object classification can be facilitated if simple diagnostic features can be used to determine class membership. Previous studies have found that simple shapes may be diagnostic for emotional content and automatically alter the allocation of visual attention. In the present study, we analyzed whether color is diagnostic of emotional content and tested whether emotionally diagnostic hues alter the allocation of visual attention. Reddish-yellow hues are more common in (i.e., diagnostic of) emotional images, particularly images with positive emotional content. An exogenous cueing paradigm was employed to test whether these diagnostic hues orient attention differently from other hues due to the emotional diagnosticity. In two experiments, we found that participants allocated attention differently to diagnostic hues than to non-diagnostic hues, in a pattern indicating a broadening of spatial attention when cued with diagnostic hues. Moreover, the attentional broadening effect was predicted by self-reported measures of affective style, linking the behavioral effect to emotional processes. These results confirm the existence and use of diagnostic features for the rapid detection of emotional content.