A spherical model of the discrimination of the emotional expressions of a schematic human face]

The four-dimensional spherical emotional space was constructed by multidimensional scaling of visually perceived differences between emotional expressions of schematic faces. In this spherical model Euclidean distances between the points representing the schematic faces are directly proportional to perceived differences of emotional expressions. Three angles of the four-dimensional sphere correspond to specific characteristics of emotions, such as emotional modality (joy, fear, anger, etc.), intensity of emotions, and emotional fullness (saturation). At the same time Cartesian coordinates represent excitations in the neuronal channels encoding line orientations. It was shown that the structure of the emotional space is similar to the structure of color space, i.e., emotional modality corresponds to color hue, emotional intensity to brightness, and emotional fullness to color saturation. The obtained evidence suggests the common mechanisms of information coding in the visual system.     

Evoked potential as a measure of perceptive and semantic differences

The informational significance of human perceptive and semantic evoked potentials to an abrupt change in non-verbal or verbal stimuli, respectively, is discussed. The amplitudes of perceptive and semantic evoked potentials were shown to be positively correlated with subjective estimates of differences between these stimuli. Multidimensional scaling of amplitude matrices and subjective estimates of differences after pair-wise replacement of the stimuli showed that colors and color names were encoded by excitation vectors of equal lengths in four-dimensional spherical space of colors. Color differences were shown to be equal to absolute values of their excitation vectors, whereas semantic differences in color names turned to be determined by the absolute values of vector differences between color memory traces represented as long-term memory excitation vectors. The data were summarized in the framework of cognitive spherical model.     

Orthogonal Relations and Color Constancy in Dichromatic Colorblindness

This paper employs uniform color space to analyze relations in dichromacy (protanopia, deuteranopia, tritanopia). Fifty percent or less of dichromats represent the classical reduction form of trichromacy, where one of three cones is inoperative but normal trichromatic color mixture such as complementary colors (pairs that mix white) are accepted by the dichromat, whose data can thus be plotted to CIE chromaticity spaces. The remaining dichromats comprise many and varied more-complex gene arrays from mutations, recombinations, etc. Though perhaps a minority, the three reductionist types provide a simple standard, in genotype and phenotype, to which the more complex remainder may be compared. Here, previously published data on dichromacy are plotted and analyzed in CIELUV uniform color space to find spatial relations in terms of color appearance space (e.g., hue angle). Traditional residual (seen) hues for protanopia and deuteranopia (both red–green colorblindness) are yellow and blue, but analysis indicates the protanopic residual hues are more greenish yellow and reddish blue than in tradition. Results for three illuminants (D65, D50, B) imply four principles in the spatial structure of dichromacy: (1) complementarity of confusion hue pairs and of residual hue pairs; (2) orthogonality of confusion locus and residual hues locus at their intersection with the white point, in each dichromatic type; (3) orthogonality of protanopic and tritanopic confusion loci; and (4) inverse relations between protanopic and tritanopic systems generally, such that one''s confusion hues are the other''s residual hues. Two of the three dichromatic systems do not represent components of normal trichromatic vision as sometimes thought but are quite different. Wavelength shifts between illuminants demonstrate chromatic adaptation correlates exactly with that in trichromatic vision. In theory these results clarify relations in and between types of dichromacy. They also apply in Munsell and CIELAB color spaces but inexactly to the degree they employ inexact complementarity.     

Molecular basis of abnormal red-green color vision: a family with three types of color vision defects

The molecular nature of three different types of X-linked color-vision defects, protanomaly, deuteranomaly, and protanopia, in a large 3-generation family was determined. In the protanomalous and protanopic males the normal red pigment gene was replaced by a 5' red-3' green fusion gene. The protanomalous male had more red pigment DNA in his fusion gene than did the more severely affected protanopic individual. The deuteranomalous individual had four green pigment genes and one 5' green-3' red fusion gene. These results extend those of Nathans et al., who proposed that most red-green color-vision defects arise as a result of unequal crossing-over between the red and green pigment genes. The various data suggest that differences in severity of color-vision defects associated with fusion genes are caused by differences in crossover sites between the red and green pigment genes. Currently used molecular methodology is not sufficiently sensitive to define these fusion points accurately, and the specific color-vision defect within the deutan or protan class cannot be predicted. The DNA patterns for color-vision genes of female heterozygotes have not previously been described. Patterns of heterozygotes may not be distinguishable from those of normals. However, a definite assignment of the various color pigment gene arrays could be carried out by family study. Two compound heterozygotes for color-vision defects who tested as normal by anomaloscopy were found to carry abnormal fusion genes. In addition, a normal red pigment gene was present on one chromosome and at least one normal green pigment gene was present on the other.(ABSTRACT TRUNCATED AT 250 WORDS)     

THE DARK ADAPTATION OF THE COLOR ANOMALOUS MEASURED WITH LIGHTS OF DIFFERENT HUES

Determinations of minimum light thresholds as a function of time in the dark have been made for four color normal, three deuteranopic (or deuteranomalous), and four protanopic (or protanomalous) subjects. Measurements were made with red, reddish orange, yellow, green, violet, and white test lights. Dark adaptation curves for the deuteranopes and deuteranomalous are essentially identical with those of the color normal for all colors. The cone portions of the protanopic dark adaptation curves measured with the red, reddish orange, yellow, and white lights are higher than the corresponding data for the color normal, the discrepancy between the two sets of data decreasing from the long to short wave lengths. Dark adaptation curves for the protanopes and protanomalous measured with green and violet light are essentially normal in appearance. A theoretical explanation is advanced to account for these findings in terms of the known sensitivity characteristics of the normal and color-anomalous eye.     

Estimation of color and brightness differences by neurons in the rabbit superior colliculus

Changes in activity of 83 neurons in the rabbit colliculus superior evoked by the replacement of eight color and eight achromatic stimuli in pairs were analyzed. It was found out that neurons displayed the early and late phasic responses (within 50-90 and 120-300 ms respectively, after the replacement) and long-term tonic response component, which depended on stimuli intensity. Analysis of phasic component revealed three neuronal groups. The first group (n=25, 30%) selected on the basis of the earliest component, was specialized to differentiate stimuli only by intensities. The perceptual spaces of these neurons reconstructed on the basis of spike discharge in the earliest response were two-dimensional. The second group of neurons (n=16, 19%) selected on the basis of the late phasic component demonstrated four-dimensional structure of perceptual space. Neurons of the third group (n=4, 5%) possessed a two-dimensional structure of perceptual space reconstructed by the analysis of the early component, whereas analysis of the late response revealed a four-dimensional structure. We suggest that information about differences between stimuli in color and intensity coming from cortical neurons is necessary for the reconstruction of four-dimensional space. The structure of perceptual spaces reconstructed on the basis of phasic responses of neurons in the colliculus superior was similar to the spaces of neurons in the primary visual cortex and lateral geniculate nucleus. The structure of perceptual space reconstructed on the basis of neuronal spikes was also similar to the space calculated from the N85 component of the visual evoked potential recorded under similar conditions. This finding confirms the general principle of vector coding in the visual system.     

Evolution of avian plumage color in a tetrahedral color space: a phylogenetic analysis of new world buntings

We use a tetrahedral color space to describe and analyze male plumage color variation and evolution in a clade of New World buntings--Cyanocompsa and Passerina (Aves: Cardinalidae). The Goldsmith color space models the relative stimulation of the four retinal cones, using the integrals of the product of plumage reflectance spectra and cone sensitivity functions. A color is represented as a vector defined by the relative stimulation of the four cone types--ultraviolet, blue, green, and red. Color vectors are plotted in a tetrahedral, or quaternary, plot with the achromatic point at the origin and the ultraviolet/violet channel along the Z-axis. Each color vector is specified by the spherical coordinates theta, phi, and r. Hue is given by the angles theta and phi. Chroma is given by the magnitude of r, the distance from the achromatic origin. Color vectors of all distinct patches in a plumage characterize the plumage color phenotype. We describe the variation in color space occupancy of male bunting plumages, using various measures of color contrast, hue contrast and diversity, and chroma. Comparative phylogenetic analyses using linear parsimony (in MacClade) and generalized least squares (GLS) models (in CONTINUOUS) with a molecular phylogeny of the group document that plumage color evolution in the clade has been very dynamic. The single best-fit GLS evolutionary model of plumage color variation over the entire clade is a directional change model with no phylogenetic correlation among species. However, phylogenetic innovations in feather color production mechanisms--derived pheomelanin and carotenoid expression in two lineages--created new opportunities to colonize novel areas of color space and fostered the explosive differentiation in plumage color. Comparison of the tetrahedral color space of Goldsmith with that of Endler and Mielke demonstrates that both provide essentially identical results. Evolution of avian ultraviolet/violet opsin sensitivity in relation to chromatic experience is discussed.     

Neuromelanin associated redox-active iron is increased in the substantia nigra of patients with Parkinson's disease

Degeneration of dopaminergic neurones during Parkinson's disease is most extensive in the subpopulation of melanized-neurones located in the substantia nigra pars compacta. Neuromelanin is a dark pigment produced in the dopaminergic neurones of the human substantia nigra and has the ability to bind a variety of metal ions, especially iron. Post-mortem analyses of the human brain have established that oxidative stress and iron content are enhanced in association with neuronal death. As redox-active iron (free Fe2+ form) and other transition metals have the ability to generate highly reactive hydroxyl radicals by a catalytic process, we investigated the redox activity of neuromelanin (NM)-aggregates in a group of parkinsonian patients, who presented a statistically significant reduction (- 70%) in the number of melanized-neurones and an increased non-heme (Fe3+) iron content as compared with a group of matched-control subjects. The level of redox activity detected in neuromelanin-aggregates was significantly increased (+ 69%) in parkinsonian patients and was highest in patients with the most severe neuronal loss. This change was not observed in tissue in the immediate vicinity of melanized-neurones. A possible consequence of an overloading of neuromelanin with redox-active elements is an increased contribution to oxidative stress and intraneuronal damage in patients with Parkinson's disease.     

The reconstruction of the perceptual spaces of brightness and color on the basis of visual evoked potentials and their comparison with the data from behavioral trials

The visual evoked potentials to a change in color stimuli were studied. The amplitude of the N85 component was correlated with color discrimination. In cases when the brightness of one color was fixed and that of the other one changed, the amplitude dynamics of N85 was V-shaped with the minimum corresponding to the point of equal brightness of both colors. The N85 amplitude in this point serves as a measure of discrimination between stimuli chromaticity. The perceptual color space in rabbit (possessing two cone pigments) was constructed in accordance with the amplitudes of N85 to color change. This space represented a hypersphere in the four-dimensional Euclidean space. The perceptual spaces for brightness and color reconstructed on the basis of conditioning probabilities and N85 amplitudes evoked by replacement of colored and achromatic stimuli were shown to coincide. This suggests the common mechanism of the vector color coding.     

In Situ Detection of a PCR-Synthesized Human Pancentromeric DNA Hybridization Probe by Color Pigment Immunostaining: Application for Dicentric Assay Automation

We report a low cost and efficient method for synthesizing a human pancentromeric DNA probe by the polymerase chain reaction (PRC) and an optimized protocol for in situ detection using color pigment immunostaining. The DNA template used in the PCR was a 2.4 kb insert containing human alphoid repeated sequences of pancentromeric DNA subcloned into pUC9 (Miller et al. 1988) and the primers hybridized to internal sequences of the 172 bp consensus tandem repeat associated with human centromeres. PCR was performed in the presence of biotin-11-dUTP, and the product was used for in situ hybridization to detect the pancentromeric region of human chromosomes in metaphase spreads. Detection of pancentromeric probe was achieved by immunoenzymatic color pigment painting to yield a permanent image detected at high resolution by bright field microscopy. The ability to synthesize the centromeric probe rapidly and to detect it with color pigment immunostaining will lead to enhanced identification and eventually to automation of various chromosome aberration assays.     

Molecular evolution of human visual pigment genes

By comparing the published DNA sequences for (a) the genes encoding the human visual color pigments (red, green, and blue) with (b) the genes encoding human, bovine, and Drosophila rhodopsins, a phylogenetic tree for the mammalian pigment genes has been constructed. This evolutionary tree shows that the common ancestor of the visual color pigment genes diverged first from that of the rhodopsin genes; then the common ancestor of the red and green pigment genes and the ancestor of the blue pigment gene diverged; and finally the red and green pigment genes diverged from each other much more recently. Nucleotide substitutions in the rhodopsin genes are best explained by the neutral theory of molecular evolution. However, important functional adaptations seem to have occurred twice during the evolution of the color pigment genes in humans: first, to the common ancestor of the three color pigment genes after its divergence from the ancestor of the rhodopsin gene and, second, to the ancestor of the red pigment gene after its divergence from that of the green pigment gene.     

Multiple visual pigments in a photoreceptor of the salamander retina

Although a given retina typically contains several visual pigments, each formed from a retinal chromophore bound to a specific opsin protein, single photoreceptor cells have been thought to express only one type of opsin. This design maximizes a cell''s sensitivity to a particular wavelength band and facilitates wavelength discrimination in retinas that process color. We report electrophysiological evidence that the ultraviolet-sensitive cone of salamander violates this rule. This cell contains three different functional opsins. The three opsins could combine with the two different chromophores present in salamander retina to form six visual pigments. Whereas rods and other cones of salamander use both chromophores, they appear to express only one type of opsin per cell. In visual pigment absorption spectra, the bandwidth at half-maximal sensitivity increases as the pigment''s wavelength maximum decreases. However, the bandwidth of the UV-absorbing pigment deviates from this trend; it is narrow like that of a red-absorbing pigment. In addition, the UV-absorbing pigment has a high apparent photosensitivity when compared with that of red- and blue-absorbing pigments and rhodopsin. These properties suggest that the mechanisms responsible for spectrally tuning visual pigments separate two absorption bands as the wavelength of maximal sensitivity shifts from UV to long wavelengths.     

对比分析四维容积超声及彩色多普勒超声在胎儿肺静脉异位引流诊断中的应用

摘要 目的：对比分析四维容积超声及彩色多普勒超声在胎儿肺静脉异位引流（APVC）诊断中的应用价值。方法：采用回顾性分析方法,2019年1月到2022年1月选择在本院进行诊治的胎儿肺静脉异位引流孕妇60例作为研究对象,都给予四维容积超声及彩色多普勒超声,记录影像学特征并判断诊断价值。结果：在60例孕妇中,彩色多普勒超声检查判断为胎儿肺静脉异位引流51例,诊断敏感性为85.0 %;四维容积超声检查判断为胎儿肺静脉异位引流59例,诊断敏感性为98.3 %,四维容积超声检查对胎儿肺静脉异位引流的诊断敏感性明显高于彩色多普勒超声检查（P<0.05）。彩色多普勒超声检查与四维容积超声检查诊断的特异性都为100.0%。在60例孕妇中,判断为胎儿肺静脉异位引流心上型32例,心下型28例;心上型的肺静脉引流途径为肺静脉-垂直静脉-右上腔静脉22例、肺静脉-垂直静脉-左上腔静脉10例,心下型的肺静脉引流途径为肺静脉-垂直静脉-左头臂静脉-右上腔静脉6例、肺静脉-垂直静脉-门静脉22例。合并心脏畸形32例,合并畸形率为53.3 %;有51例孕妇终止妊娠,9例孕妇继续妊娠,其中8例未经治疗者新生儿期死亡,1例在3月龄死亡。结论：相对于彩色多普勒超声,四维容积超声在胎儿肺静脉异位引流诊断中的应用可提高诊断敏感性,可有效反映肺静脉回流情况,可指导临床进行早期干预。     

Characterizing the Human Cone Photoreceptor Mosaic via Dynamic Photopigment Densitometry

Densitometry is a powerful tool for the biophysical assessment of the retina. Until recently, this was restricted to bulk spatial scales in living humans. The application of adaptive optics (AO) to the conventional fundus camera and scanning laser ophthalmoscope (SLO) has begun to translate these studies to cellular scales. Here, we employ an AOSLO to perform dynamic photopigment densitometry in order to characterize the optical properties and spectral types of the human cone photoreceptor mosaic. Cone-resolved estimates of optical density and photosensitivity agree well with bulk estimates, although show smaller variability than previously reported. Photopigment kinetics of individual cones derived from their selective bleaching allowed efficient mapping of cone sub-types in human retina. Estimated uncertainty in identifying a cone as long vs middle wavelength was less than 5%, and the total time taken per subject ranged from 3–9 hours. Short wavelength cones were delineated in every subject with high fidelity. The lack of a third cone-type was confirmed in a protanopic subject. In one color normal subject, cone assignments showed 91% correspondence against a previously reported cone-typing method from more than a decade ago. Combined with cone-targeted stimulation, this brings us closer in studying the visual percept arising from a specific cone type and its implication for color vision circuitry.     

Storage Stability and Thermal Stability of Hordeumin,an Anthocyanin Pigment from Barley

Hordeumin stored at –40 to –80^oC in 1% HCI–methanol suffered neither from color reduction nor discoloration. After heating at 80°C for 60 min, hordeumin showed a pigment retention rate of 100%. This characteristic is because the pigment is a composite high-molecular weight compound consisting of anthocyanins and polyphenols, It was determined, however, that discoloration and browning occurred more rapidly than color reduction during storage and heating of the pigment.     

Interaction of several mono- and dihydroxybenzene derivatives of various depigmenting potencies with L-3,4-dihydroxyphenylalanine-melanin

Certain mono- and dihydroxybenzene derivatives cause depigmentation of skin and hair, and appear to be selectively cytotoxic for melanized pigment cells. As direct physical and/or chemical interaction between depigmenter (DP) and pigment melanin may play a role in depigmentation, we have carried out preliminary studies in model systems where such interactions may easily be separated from effects due to tyrosinase, melanosomal proteins, and other components. We have used synthetic L-3,4-hydroxyphenylalanine (L-DOPA)-melanin as a protein-free model pigment and potassium ferricyanide as a model electron acceptor. Compounds studied were catechol, 4-t-butylcatechol, 4-methylcatechol, 3,4-dihydroxyphenylalanine (DOPA), 3,4-dihydroxyphenylacetic acid, hydroquinone, 4-methoxyphenol, 4-t-butylphenol, and 2,6, di-t-butyl-4-methylphenol (BHT) in 0.1 M phosphate buffer, pH 7.4. These compounds vary widely in their ability to depigment hair and skin. Ferricyanide reduction by DP in the presence and absence of melanin was monitored spectrophotometrically. The sparingly soluble BHT and 4-t-butylphenol did not reduce ferricyanide in the absence or presence of melanin. For the other compounds, kinetic analysis demonstrated direct interaction between each DP and melanin. Except for dihydroxyphenylacetic acid, reduction kinetics were consistent with a mechanism involving noninteractive binding of both DP and ferricyanide to melanin prior to coupled electron transfer through the melanin backbone. Kinetic analysis afforded KB, a thermodynamic constant (M-1) for DP-melanin binding, and k', a rate parameter (M s-1) for electron transfer. A dimensionless enhancement factor (EF) was defined as k'KB/ks, with ks a pseudo-first-order constant (s-1) for ferricyanide reduction in the absence of melanin. Depending on the reductant, melanin either retards (EF less than 1) or accelerates (EF greater than 1) the rate of ferricyanide reduction. There appears to be a direct relationship between EF and depigmenting potency. There is no relationship between depigmenting power and the ability per se of the DP to bind to melanin or to reduce ferricyanide.     

Vector representation of associative learning

I. P. Pavlov [12] has shown that conditioned reflexes are selective both with respect to conditioned stimuli and to conditioned reflexes elicited by those conditioned stimuli. At the neuronal level selective aspects of conditioned stimuli are based on detectors selectively tuned to respective stimuli. The selective aspects of conditioned reflexes are due to command neurons representing specific unconditioned reflexes. It can be assumed that conditioned reflexes result from association between selective detectors and specific command neurons. The detectors activated by a conditioned stimulus constitute a combination of excitations--a detector excitation vector. The detector excitation vector acts on a command neuron via a set of plastic synapses--a synaptic weight vector. Plastic synapses are modified in the process of learning making command neuron selectively tuned to a specific conditioned stimulus. The selective tuning of a particular command neuron to a specific excitation vector referred to a conditioned stimulus is a basis of associative learning. The probabilities of conditioned reflexes elicited by conditioned and differential stimuli implicitly contain information concerning excitation vectors that encode respective stimuli. Contribution of the vector code to associative learning was explored combining differential color conditioning with intracellular recording from color-coding neurons. It was shown that colors in carps and monkeys are represented on a hypersphere in the four-dimensional space similar to human color space. The basis of the color space is constituted by red-green, blue-yellow, brightness and darkness neurons.     

De novo synthesis of phytochrome in pumpkin hooks

Phytochrome becomes density labeled in the hook of pumpkin (Cucurbita pepo L.) seedlings grown in the dark on D₂O, indicating that the protein moiety of the pigment is synthesized de novo during development. Red light causes a rapid decline of the total phytochrome level in the hook of etiolated seedlings but upon return to the dark, phytochrome again accumulates. These newly appearing molecules are also synthesized de novo. Newly synthesized phytochrome in both dark-grown and red-irradiated seedlings is in the red-absorbing form. Turnover of the red-absorbing form is indicated by the density labeling of phytochrome during a period when the total phytochrome level in the hook of dark-grown seedlings remains constant. However, it was not possible to determine whether this results from intracellular turnover or turnover of the whole cell population during hook growth.