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Martinovic J, Boyanova A, Andersen SK. Division and spreading of attention across color. Cereb Cortex 2024; 34:bhae240. [PMID: 38858841 PMCID: PMC11164655 DOI: 10.1093/cercor/bhae240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 05/16/2024] [Indexed: 06/12/2024] Open
Abstract
Biological systems must allocate limited perceptual resources to relevant elements in their environment. This often requires simultaneous selection of multiple elements from the same feature dimension (e.g. color). To establish the determinants of divided attentional selection of color, we conducted an experiment that used multicolored displays with four overlapping random dot kinematograms that differed only in hue. We manipulated (i) requirement to focus attention to a single color or divide it between two colors; (ii) distances of distractor hues from target hues in a perceptual color space. We conducted a behavioral and an electroencephalographic experiment, in which each color was tagged by a specific flicker frequency and driving its own steady-state visual evoked potential. Behavioral and neural indices of attention showed several major consistencies. Concurrent selection halved the neural signature of target enhancement observed for single targets, consistent with an approximately equal division of limited resources between two hue-selective foci. Distractors interfered with behavioral performance in a context-dependent fashion but their effects were asymmetric, indicating that perceptual distance did not adequately capture attentional distance. These asymmetries point towards an important role of higher-level mechanisms such as categorization and grouping-by-color in determining the efficiency of attentional allocation in complex, multicolored scenes.
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Affiliation(s)
- Jasna Martinovic
- School of Philosophy, Psychology and Language Sciences, University of Edinburgh, 7 George Square, EH8 9JZ, Edinburgh, United Kingdom
| | - Antoniya Boyanova
- School of Psychology, University of Aberdeen, William Guild Building, AB24 3UB, Aberdeen, United Kingdom
| | - Søren K Andersen
- School of Psychology, University of Aberdeen, William Guild Building, AB24 3UB, Aberdeen, United Kingdom
- Department of Psychology, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark
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2
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Martinovic J. Acquisition of colour categories through learning: Differences between hue and lightness. Cognition 2024; 242:105657. [PMID: 37980878 DOI: 10.1016/j.cognition.2023.105657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 09/20/2023] [Accepted: 10/30/2023] [Indexed: 11/21/2023]
Abstract
Colour categories are acquired through learning, but the nature of this process is not fully understood. Some category distinctions are defined by hue (e.g. red/purple) but other by lightness (red/pink). The aim of this study was to investigate if the acquisition of key information for making accurate cross-boundary discriminations poses different challenges for hue-defined as opposed to lightness-defined boundaries. To answer this question, hue- and lightness-learners were trained on a novel category boundary within the GREEN region of colour space. After training, hue- and lightness-learners as well as untrained controls performed delayed same-different discrimination for lightness and hue pairs. In addition to discrimination data, errors during learning and category-labelling strategies were examined. Errors during learning distributed non-uniformly and in accordance with the Bezold-Brücke effect, which accounts for darker colours at the green-blue boundary appearing greener and lighter colours appearing bluer. Only hue-learners showed discrimination improvements due to category boundary acquisition. Thus, acquisition is more efficient for hue-category compared to lightness-category boundaries. Almost all learners reported using category-labelling strategies, with hue-learners almost exclusively using 'green'/'blue' and lightness learners using a wider range of labels, most often 'light'/'dark'. Thus, labels play an important role in colour category learning and such labelling does not conform to everyday naming: here, the label 'blue' is used for exemplars that would normally be named 'green'. In conclusion, labelling serves the purpose of highlighting key information that differentiates exemplars across the category boundary, and basic colour terms may be particularly effective in facilitating such attentional guidance.
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Affiliation(s)
- Jasna Martinovic
- Department of Psychology, School of Philosophy, Psychology and Linguistics, University of Edinburgh, 7 George Square, EH8 9JZ Edinburgh, Scotland, UK.
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3
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van Leeuwen JEP, McDougall A, Mylonas D, Suárez-González A, Crutch SJ, Warren JD. Pupil responses to colorfulness are selectively reduced in healthy older adults. Sci Rep 2023; 13:22139. [PMID: 38092848 PMCID: PMC10719259 DOI: 10.1038/s41598-023-48513-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 11/27/2023] [Indexed: 12/17/2023] Open
Abstract
The alignment between visual pathway signaling and pupil dynamics offers a promising non-invasive method to further illuminate the mechanisms of human color perception. However, only limited research has been done in this area and the effects of healthy aging on pupil responses to the different color components have not been studied yet. Here we aim to address this by modelling the effects of color lightness and chroma (colorfulness) on pupil responses in young and older adults, in a closely controlled passive viewing experiment with 26 broad-spectrum digital color fields. We show that pupil responses to color lightness and chroma are independent from each other in both young and older adults. Pupil responses to color lightness levels are unaffected by healthy aging, when correcting for smaller baseline pupil sizes in older adults. Older adults exhibit weaker pupil responses to chroma increases, predominantly along the Green-Magenta axis, while relatively sparing the Blue-Yellow axis. Our findings complement behavioral studies in providing physiological evidence that colors fade with age, with implications for color-based applications and interventions both in healthy aging and later-life neurodegenerative disorders.
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Affiliation(s)
- Janneke E P van Leeuwen
- Dementia Research Centre, UCL Queen Square Institute of Neurology, University College London, 8-11 Queen Square, London, WC1N 3AR, UK.
- The Thinking Eye, ACAVA Limehouse Arts Foundation, London, UK.
| | - Amy McDougall
- Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, UK
| | - Dimitris Mylonas
- Faculty of Philosophy, Northeastern University London, London, UK
| | - Aida Suárez-González
- Dementia Research Centre, UCL Queen Square Institute of Neurology, University College London, 8-11 Queen Square, London, WC1N 3AR, UK
| | - Sebastian J Crutch
- Dementia Research Centre, UCL Queen Square Institute of Neurology, University College London, 8-11 Queen Square, London, WC1N 3AR, UK
| | - Jason D Warren
- Dementia Research Centre, UCL Queen Square Institute of Neurology, University College London, 8-11 Queen Square, London, WC1N 3AR, UK.
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4
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Toscani M, Wolf P, Gegenfurtner KR, Braun DI. Context effects on the perception of saturation of fruit colors in still-life paintings. J Vis 2023; 23:8. [PMID: 37971768 PMCID: PMC10664727 DOI: 10.1167/jov.23.13.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 09/29/2023] [Indexed: 11/19/2023] Open
Abstract
Still-life painters, especially of the so-called Golden Age (17th century) in the Netherlands, are famous for their masterful techniques of rendering reality. Their amazing abilities to depict different material properties of fruits and flowers are stunning. But how important are these careful arrangements of different objects for the perception of an individual item? Is the perceived color saturation of a single fruit influenced by its surrounding context? We selected fruits in still-life paintings as stimuli to investigate whether and how perceived saturations of fruits were affected by their original contexts. In our study, we focused especially on effects of five context properties: complementary colors, chromatic and luminance contrast, object overlap, and surround variance. Six fruit varieties depicted in high-quality digital reproductions of 48 classic and eight varieties in 64 more recent, modern still-life paintings were selected. In a single trial, eight images of fruits of the same variety appeared on a neutral gray background; half were single fruit cutouts, and the other half were the same fruits embedded in their circular contexts. Fifteen participants ranked all eight images according to perceived color saturations of the fruits. Saturation ratings showed a high agreement of 77%. Surrounding contexts led to an increase in perceived saturation of central fruits. This effect was mainly driven by object overlap, the presence of the central fruit type also in the context, and surround variance. Chroma contrast between fruits and contexts decreased saturation significantly. No significant context effects were found for complementary colors or luminance contrast. Our results show that in paintings, many of the cues that are usually experimentally isolated occur in interesting combinations and lead to an increase in perceived saturation that makes fruit objects more appealing and convincing.
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Affiliation(s)
- Matteo Toscani
- Psychology Department, Giessen University, Giessen, Germany
- Psychology Department, Bournemouth University, Poole, UK
| | - Paulina Wolf
- Psychology Department, Giessen University, Giessen, Germany
| | | | - Doris I Braun
- Psychology Department, Giessen University, Giessen, Germany
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5
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Morimoto T, Akbarinia A, Storrs K, Cheeseman JR, Smithson HE, Gegenfurtner KR, Fleming RW. Color and gloss constancy under diverse lighting environments. J Vis 2023; 23:8. [PMID: 37432844 PMCID: PMC10351023 DOI: 10.1167/jov.23.7.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2023] Open
Abstract
When we look at an object, we simultaneously see how glossy or matte it is, how light or dark, and what color. Yet, at each point on the object's surface, both diffuse and specular reflections are mixed in different proportions, resulting in substantial spatial chromatic and luminance variations. To further complicate matters, this pattern changes radically when the object is viewed under different lighting conditions. The purpose of this study was to simultaneously measure our ability to judge color and gloss using an image set capturing diverse object and illuminant properties. Participants adjusted the hue, lightness, chroma, and specular reflectance of a reference object so that it appeared to be made of the same material as a test object. Critically, the two objects were presented under different lighting environments. We found that hue matches were highly accurate, except for under a chromatically atypical illuminant. Chroma and lightness constancy were generally poor, but these failures correlated well with simple image statistics. Gloss constancy was particularly poor, and these failures were only partially explained by reflection contrast. Importantly, across all measures, participants were highly consistent with one another in their deviations from constancy. Although color and gloss constancy hold well in simple conditions, the variety of lighting and shape in the real world presents significant challenges to our visual system's ability to judge intrinsic material properties.
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Affiliation(s)
- Takuma Morimoto
- Justus Liebig University Giessen, Giessen, Germany
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | | | - Katherine Storrs
- Justus Liebig University Giessen, Giessen, Germany
- School of Psychology, University of Auckland, New Zealand
| | - Jacob R Cheeseman
- Justus Liebig University Giessen, Giessen, Germany
- Center for Mind, Brain and Behavior (CMBB), Universities of Marburg, Giessen and Darmstadt, Germany
| | - Hannah E Smithson
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | | | - Roland W Fleming
- Justus Liebig University Giessen, Giessen, Germany
- Center for Mind, Brain and Behavior (CMBB), Universities of Marburg, Giessen and Darmstadt, Germany
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Hedjar L, Toscani M, Gegenfurtner KR. Perception of saturation in natural objects. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2023; 40:A190-A198. [PMID: 37133037 DOI: 10.1364/josaa.476874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The distribution of colors across a surface depends on the interaction between its surface properties, its shape, and the lighting environment. Shading, chroma, and lightness are positively correlated: points on the object that have high luminance also have high chroma. Saturation, typically defined as the ratio of chroma to lightness, is therefore relatively constant across an object. Here we explored to what extent this relationship affects perceived saturation of an object. Using images of hyperspectral fruit and rendered matte objects, we manipulated the lightness-chroma correlation (positive or negative) and asked observers which of two objects appeared more saturated. Despite the negative-correlation stimulus having greater mean and maximum chroma, lightness, and saturation than the positive, observers overwhelmingly chose the positive as more saturated. This suggests that simple colorimetric statistics do not accurately represent perceived saturation of objects-observers likely base their judgments on interpretations about the cause of the color distribution.
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7
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Marlow PJ, Gegenfurtner KR, Anderson BL. The role of color in the perception of three-dimensional shape. Curr Biol 2022; 32:1387-1394.e3. [PMID: 35139361 PMCID: PMC8967406 DOI: 10.1016/j.cub.2022.01.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/13/2021] [Accepted: 01/10/2022] [Indexed: 12/02/2022]
Abstract
The human visual system can derive information about three-dimensional (3D) shape from the structure of light reflected by surfaces. Most research on single static images has focused on the 3D shape information contained in variations of brightness caused by interactions between the illumination and local surface orientation (“shading”).1, 2, 3, 4, 5, 6 Although color can enhance the recovery of surface shading when color and brightness vary independently,7, 8, 9 there is no evidence that color alone provides any information about 3D shape. Here, we show that the wavelength-dependent reflectance of chromatic materials provides information about the 3D shape of translucent materials. We show that different wavelengths of light undergo varying degrees of subsurface light transport, which generates multiple forms of spatial structure: wavelengths that are weakly reflected generate shading-like image structure, linked to 3D surface orientation, whereas wavelengths that penetrate more deeply into the material are primarily constrained by the direction of surface curvature (convexities and concavities).10 Psychophysical experiments demonstrate that the enhanced perception of 3D shape in chromatic translucent surfaces arises from the shading structure generated by weakly reflected wavelengths, which, in turn, generates correlated spatial variations in saturation. These results demonstrate a new functional role for color in the perception of the 3D shape of translucent materials. Color carries information used to perceive three-dimensional shape Translucent surfaces internally scatter some wavelengths of light more than others Wavelengths weakly scattered carry information about surface orientation Wavelengths strongly scattered carry information about surface curvature
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Affiliation(s)
- Phillip J Marlow
- The University of Sydney, School of Psychology, Sydney, NSW 2006, Australia.
| | - Karl R Gegenfurtner
- Giessen University, Department of Psychology, 23 Ludwigstrasse, 35390 Giessen, Germany
| | - Barton L Anderson
- The University of Sydney, School of Psychology, Sydney, NSW 2006, Australia.
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8
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Shi Y, Yao X, Xu J, Hu X, Tu L, Lan F, Cui J, Cui L, Huang J, Li J, Bi Z, Li J. A New Approach of Fatigue Classification Based on Data of Tongue and Pulse With Machine Learning. Front Physiol 2022; 12:708742. [PMID: 35197858 PMCID: PMC8859319 DOI: 10.3389/fphys.2021.708742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 11/03/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Fatigue is a common and subjective symptom, which is associated with many diseases and suboptimal health status. A reliable and evidence-based approach is lacking to distinguish disease fatigue and non-disease fatigue. This study aimed to establish a method for early differential diagnosis of fatigue, which can be used to distinguish disease fatigue from non-disease fatigue, and to investigate the feasibility of characterizing fatigue states in a view of tongue and pulse data analysis. METHODS Tongue and Face Diagnosis Analysis-1 (TFDA-1) instrument and Pulse Diagnosis Analysis-1 (PDA-1) instrument were used to collect tongue and pulse data. Four machine learning models were used to perform classification experiments of disease fatigue vs. non-disease fatigue. RESULTS The results showed that all the four classifiers over "Tongue & Pulse" joint data showed better performances than those only over tongue data or only over pulse data. The model accuracy rates based on logistic regression, support vector machine, random forest, and neural network were (85.51 ± 1.87)%, (83.78 ± 4.39)%, (83.27 ± 3.48)% and (85.82 ± 3.01)%, and with Area Under Curve estimates of 0.9160 ± 0.0136, 0.9106 ± 0.0365, 0.8959 ± 0.0254 and 0.9239 ± 0.0174, respectively. CONCLUSION This study proposed and validated an innovative, non-invasive differential diagnosis approach. Results suggest that it is feasible to characterize disease fatigue and non-disease fatigue by using objective tongue data and pulse data.
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Affiliation(s)
- Yulin Shi
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Pudong, China
| | - Xinghua Yao
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Pudong, China
| | - Jiatuo Xu
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Pudong, China
| | - Xiaojuan Hu
- Shanghai Innovation Center of TCM Health Service, Shanghai University of Traditional Chinese Medicine, Pudong, China
| | - Liping Tu
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Pudong, China
| | - Fang Lan
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Pudong, China
| | - Ji Cui
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Pudong, China
| | - Longtao Cui
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Pudong, China
| | - Jingbin Huang
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Pudong, China
| | - Jun Li
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Pudong, China
| | - Zijuan Bi
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Pudong, China
| | - Jiacai Li
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Pudong, China
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9
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Shi Y, Hu X, Cui J, Li J, Bi Z, Li J, Fu H, Wang Y, Cui L, Xu J. Correlation Analysis of Data of Tongue and Pulse in Patients With Disease Fatigue and Sub-health Fatigue. INQUIRY: THE JOURNAL OF HEALTH CARE ORGANIZATION, PROVISION, AND FINANCING 2022; 59:469580211060781. [PMID: 35112891 PMCID: PMC8819780 DOI: 10.1177/00469580211060781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Fatigue is one of the most common subjective symptoms of abnormal health state,
there is still no reliable and stable evaluation method to distinguish disease
fatigue and non-disease fatigue. Studies have shown that tongue diagnosis and
pulse diagnosis are the reflection of overall state of the body. This study aims
to explore the distribution rules and correlation of data of tongue and pulse in
population with disease fatigue and sub-health fatigue and provide a new method
of clinical diagnosis of fatigue from the perspective of tongue diagnosis and
pulse diagnosis. In this study, a total of 736 people were selected and divided
into healthy controls (n = 250), sub-health fatigue group (n = 242), and disease
fatigue group (n = 244). TFDA-1 tongue diagnosis instrument and PDA-1 pulse
diagnosis instrument were used to collect tongue image and sphygmogram, simple
correlation analysis and canonical correlation analysis were used to analyze the
correlation of tongue and pulse data about the two groups of fatigue people. The
study had shown that tongue and pulse data could provide a certain reference for
the diagnosis of different types of fatigue, tongue and pulse data in disease
fatigue and sub-health fatigue population had different distribution rules, and
there was a simple correlation and canonical correlation in the disease fatigue
population, the coefficient of canonical correlation was .649 (P <.05).
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Affiliation(s)
- Yulin Shi
- Department of Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xiaojuan Hu
- Shanghai Collaborative Innovation Center of Health Service in Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ji Cui
- Department of Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jun Li
- Department of Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zijuan Bi
- Department of Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jiacai Li
- Department of Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Hongyuan Fu
- Department of Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yu Wang
- Department of Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Longtao Cui
- Department of Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jiatuo Xu
- Department of Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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10
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A New Method for Syndrome Classification of Non-Small-Cell Lung Cancer Based on Data of Tongue and Pulse with Machine Learning. BIOMED RESEARCH INTERNATIONAL 2021; 2021:1337558. [PMID: 34423031 PMCID: PMC8373490 DOI: 10.1155/2021/1337558] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 07/12/2021] [Accepted: 07/23/2021] [Indexed: 12/18/2022]
Abstract
Objective To explore the data characteristics of tongue and pulse of non-small-cell lung cancer with Qi deficiency syndrome and Yin deficiency syndrome, establish syndrome classification model based on data of tongue and pulse by using machine learning methods, and evaluate the feasibility of syndrome classification based on data of tongue and pulse. Methods We collected tongue and pulse of non-small-cell lung cancer patients with Qi deficiency syndrome (n = 163), patients with Yin deficiency syndrome (n = 174), and healthy controls (n = 185) using intelligent tongue diagnosis analysis instrument and pulse diagnosis analysis instrument, respectively. We described the characteristics and examined the correlation of data of tongue and pulse. Four machine learning methods, namely, random forest, logistic regression, support vector machine, and neural network, were used to establish the classification models based on symptom, tongue and pulse, and symptom and tongue and pulse, respectively. Results Significant difference indices of tongue diagnosis between Qi deficiency syndrome and Yin deficiency syndrome were TB-a, TB-S, TB-Cr, TC-a, TC-S, TC-Cr, perAll, and the tongue coating texture indices including TC-CON, TC-ASM, TC-MEAN, and TC-ENT. Significant difference indices of pulse diagnosis were t4 and t5. The classification performance of each model based on different datasets was as follows: tongue and pulse < symptom < symptom and tongue and pulse. The neural network model had a better classification performance for symptom and tongue and pulse datasets, with an area under the ROC curves and accuracy rate which were 0.9401 and 0.8806. Conclusions It was feasible to use tongue data and pulse data as one of the objective diagnostic basis in Qi deficiency syndrome and Yin deficiency syndrome of non-small-cell lung cancer.
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Abstract
Visual images can be described in terms of the illuminants and objects that are causal to the light reaching the eye, the retinal image, its neural representation, or how the image is perceived. Respecting the differences among these distinct levels of description can be challenging but is crucial for a clear understanding of color vision. This article approaches color by reviewing what is known about its neural representation in the early visual cortex, with a brief description of signals in the eye and the thalamus for context. The review focuses on the properties of single neurons and advances the general theme that experimental approaches based on knowledge of feedforward signals have promoted greater understanding of the neural code for color than approaches based on correlating single-unit responses with color perception. New data from area V1 illustrate the strength of the feedforward approach. Future directions for progress in color neurophysiology are discussed: techniques for improved single-neuron characterization, for investigations of neural populations and small circuits, and for the analysis of natural image statistics.
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Affiliation(s)
- Gregory D Horwitz
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195, USA; .,Washington National Primate Research Center, University of Washington, Seattle, Washington 98121, USA
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12
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Basson EP, Zeiler GE, Kamerman PR, Meyer LCR. Use of blood colour for assessment of arterial oxygen saturation in immobilized impala (Aepyceros melampus). Vet Anaesth Analg 2021; 48:725-733. [PMID: 34362689 DOI: 10.1016/j.vaa.2021.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 03/07/2021] [Accepted: 05/06/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To determine the relationship between arterial blood colour [as defined by the International Commission on Illumination (CIE) L∗a∗b∗ colour space] and haemoglobin oxygen saturation [functional saturation (SaO2) and fractional saturation (FO2Hb)], and if arterial blood colour can be used to predict arterial haemoglobin oxygen saturation. STUDY DESIGN Descriptive study as an adjunct to two prospective randomized crossover studies. ANIMALS A group of 10 wild caught adult female impala (Aepyceros melampus) weighing 34.1 ± 5.2 kg (mean ± standard deviation). METHODS Impala were immobilized with potent opioids (0.09 mg kg-1 of etorphine or thiafentanil). A total of 163 arterial blood samples were collected anaerobically into heparinized syringes from arterial cannulae and analysed immediately using spectrocolourimetry and co-oximetry. Data were analysed by modelling the relationship between predicted arterial blood colour CIE L∗a∗b∗ components and SaO2 and FO2Hb. The models were then used to predict values for L∗, a∗ and b∗ to produce a colour palette for the range of SaO2 and FO2Hb used. The modified version of the Farnsworth-Munsell hue test was used to assess the subjective ordering of the resulting colour palette by 20 observers. RESULTS The second-order polynomial (quadratic) model produced the best fit for all three arterial blood colour CIE L∗a∗b∗ components for both SaO2 and FO2Hb. The regression models were used to generate predicted arterial blood colour CIE L∗a∗b∗ components for the midpoint of each decile over a range of SaO2 and FO2Hb percentages (15% to 95%). The resulting colour palettes were correctly ordered by all observers in the SaO2 range of 45-95% saturation. CONCLUSIONS AND CLINICAL RELEVANCE An association between arterial blood colour (as defined by CIE L∗a∗b∗ components) and SaO2 and FO2Hb exists, and arterial blood colour can be used to give a clinically useful estimate of arterial haemoglobin oxygen saturation in impala.
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Affiliation(s)
- Etienne P Basson
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa; Centre for Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
| | - Gareth E Zeiler
- Centre for Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa; Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Peter R Kamerman
- School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Leith C R Meyer
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa; Centre for Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
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13
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Isherwood ZJ, Huynh-Thu Q, Arnison M, Monaghan D, Toscani M, Perry S, Honson V, Kim J. Surface properties and the perception of color. J Vis 2021; 21:7. [PMID: 33576764 PMCID: PMC7888285 DOI: 10.1167/jov.21.2.7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We examined whether perception of color saturation and lightness depends on the three-dimensional (3D) shape and surface gloss of surfaces rendered to have different hues. In Experiment 1, we parametrically varied specular roughness of predominantly planar surfaces with different mesoscopic relief heights. The orientation of surfaces was varied relative to the light source and observer. Observers matched perceived lightness and chroma (effectively saturation) using spherical objects rendered using CIE LCH color space. We observed strong interactions between perceived saturation and lightness with changes in surface orientation and surface properties (specular roughness and 3D relief height). Declines in saturation and increases in lightness were observed with increasing specular roughness. Changes in relief height had greater effects on perceived saturation and lightness for blue hues compared with reddish and greenish hues. Experiment 2 found inverse correlations between perceived gloss and specular roughness across conditions. Experiment 3 estimated perceived specular coverage and found that a weighted combination of perceived gloss and specular coverage could account for perceived color saturation and lightness, with different coefficients accounting for the perceptual experience for each of the three hue conditions. These findings suggest that perceived color saturation and lightness depend on the separation of specular highlights from diffuse shading informative of chromatic surface reflectance.
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Affiliation(s)
- Zoey J Isherwood
- School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia.,Department of Psychology, University of Nevada, Reno, NV, USA.,
| | - Quan Huynh-Thu
- Canon Information Systems Research Australia, Macquarie Park, New South Wales, Australia.,Nearmap, Sydney, New South Wales, Australia.,
| | - Matthew Arnison
- Canon Information Systems Research Australia, Macquarie Park, New South Wales, Australia.,Bandicoot Imaging Sciences, Sydney, New South Wales, Australia.,
| | - David Monaghan
- Canon Information Systems Research Australia, Macquarie Park, New South Wales, Australia.,Bandicoot Imaging Sciences, Sydney, New South Wales, Australia.,
| | - Matteo Toscani
- Abteilung Allgemeine Psychologie, Justus-Liebig-Universität Giessen, Giessen, Germany.,
| | - Stuart Perry
- Faculty of Engineering and IT, University of Technology Sydney, Sydney, New South Wales, Australia.,
| | - Vanessa Honson
- School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia.,
| | - Juno Kim
- School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia.,
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14
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Shi Y, Hu X, Cui J, Cui L, Huang J, Ma X, Jiang T, Yao X, Lan F, Li J, Bi Z, Li J, Wang Y, Fu H, Wang J, Lin Y, Bai J, Guo X, Tu L, Xu J. Clinical data mining on network of symptom and index and correlation of tongue-pulse data in fatigue population. BMC Med Inform Decis Mak 2021; 21:72. [PMID: 33627103 PMCID: PMC7905588 DOI: 10.1186/s12911-021-01410-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 01/28/2021] [Indexed: 12/19/2022] Open
Abstract
Background Fatigue is a kind of non-specific symptom, which occurs widely in sub-health and various diseases. It is closely related to people's physical and mental health. Due to the lack of objective diagnostic criteria, it is often neglected in clinical diagnosis, especially in the early stage of disease. Many clinical practices and researches have shown that tongue and pulse conditions reflect the body's overall state. Establishing an objective evaluation method for diagnosing disease fatigue and non-disease fatigue by combining clinical symptom, index, and tongue and pulse data is of great significance for clinical treatment timely and effectively. Methods In this study, 2632 physical examination population were divided into healthy controls, sub-health fatigue group, and disease fatigue group. Complex network technology was used to screen out core symptoms and Western medicine indexes of sub-health fatigue and disease fatigue population. Pajek software was used to construct core symptom/index network and core symptom-index combined network. Simultaneously, canonical correlation analysis was used to analyze the objective tongue and pulse data between the two groups of fatigue population and analyze the distribution of tongue and pulse data. Results Some similarities were found in the core symptoms of sub-health fatigue and disease fatigue population, but with different node importance. The node-importance difference indicated that the diagnostic contribution rate of the same symptom to the two groups was different. The canonical correlation coefficient of tongue and pulse data in the disease fatigue group was 0.42 (P < 0.05), on the contrast, correlation analysis of tongue and pulse in the sub-health fatigue group showed no statistical significance. Conclusions The complex network technology was suitable for correlation analysis of symptoms and indexes in fatigue population, and tongue and pulse data had a certain diagnostic contribution to the classification of fatigue population.
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Affiliation(s)
- Yulin Shi
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Xiaojuan Hu
- Shanghai Innovation Center of TCM Health Service, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Ji Cui
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Longtao Cui
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Jingbin Huang
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Xuxiang Ma
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Tao Jiang
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Xinghua Yao
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Fang Lan
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Jun Li
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Zijuan Bi
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Jiacai Li
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Yu Wang
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Hongyuan Fu
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Jue Wang
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Yanting Lin
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Jingxuan Bai
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Xiaojing Guo
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Liping Tu
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China.
| | - Jiatuo Xu
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China.
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15
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Blurring of ancient wall paintings caused by binder decay in the pigment layer. Sci Rep 2020; 10:21075. [PMID: 33273650 PMCID: PMC7713070 DOI: 10.1038/s41598-020-78117-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 10/26/2020] [Indexed: 11/24/2022] Open
Abstract
In this paper, the effect of binder decay rather than a change in the pigments on the blurring of ancient wall paintings was researched. The simulated wall paintings were prepared by brushing an aqueous solution containing gelatine and ochre grains on the surface of cylindrical compressed soil samples. Then, the dried samples were calcined at 650 °C for 2 h to obtain the simulated wall paintings with the degraded binder gelatine. Next, the calcined samples were brushed with a certain amount of acetone solution containing an ionic liquid ([BMIm]PF6) to obtain the corresponding repaired samples. Based on the results from various characterization methods (UV–vis, FTIR, XRD, XPS, SEM, TG), the following conclusions were drawn. The degradation of the binder caused by calcination increases the surface roughness of the painting layer, resulting in enhanced scattering. In this case, because scattering decrease the light absorption by the pigments, even if unchanged pigment exists in the painting layer, its colour can become blurred. The filling of the ionic liquid into the pores caused by gelatine decay in the painting layer can decrease the scattering, and the blurred colour can be restored to some extent. As typical examples, this principle was successfully applied to restore the blurred colour of an ancient Chinese wall painting (Tang Dynasty) and a pottery (Eastern Han Dynasty).
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16
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Yang Y, Li Z, Wu S. Low-Light Image Brightening via Fusing Additional Virtual Images. SENSORS 2020; 20:s20164614. [PMID: 32824474 PMCID: PMC7472317 DOI: 10.3390/s20164614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 11/24/2022]
Abstract
Capturing high-quality images via mobile devices in low-light or backlighting conditions is very challenging. In this paper, a new, single image brightening algorithm is proposed to enhance an image captured in low-light conditions. Two virtual images with larger exposure times are generated to increase brightness and enhance fine details of the underexposed regions. In order to reduce the brightness change, the virtual images are generated via intensity mapping functions (IMFs) which are computed using available camera response functions (CRFs). To avoid possible color distortion in the virtual image due to one-to-many mapping, a least square minimization problem is formulated to determine brightening factors for all pixels in the underexposed regions. In addition, an edge-preserving smoothing technique is adopted to avoid noise in the underexposed regions from being amplified in the virtual images. The final brightened image is obtained by fusing the original image and two virtual images via a gradient domain guided image filtering (GGIF) based multiscale exposure fusion (MEF) with properly defined weights for all the images. Experimental results show that the relative brightness and color are preserved better by the proposed algorithm. The details in bright regions are also preserved well in the final image. The proposed algorithm is expected to be useful for computational photography on smart phones.
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Affiliation(s)
- Yi Yang
- Institute of Robotics and Intelligent Systems, School of Information Science and Engineering, Wuhan University of Science and Technology, Wuhan 430081, China;
| | - Zhengguo Li
- Institute for Infocomm Research, Singapore 138632, Singapore;
| | - Shiqian Wu
- Institute of Robotics and Intelligent Systems, School of Information Science and Engineering, Wuhan University of Science and Technology, Wuhan 430081, China;
- Correspondence: ; Tel.: +86-136-2711-4410
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17
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Schloss KB, Witzel C, Lai LY. Blue hues don't bring the blues: questioning conventional notions of color-emotion associations. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2020; 37:813-824. [PMID: 32400715 DOI: 10.1364/josaa.383588] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 03/15/2020] [Indexed: 06/11/2023]
Abstract
It is commonly held that yellow is happy and blue is sad, but the reason remains unclear. Part of the problem is that researchers tend to focus on understanding why yellow is happy and blue is sad, but this may be a misleading characterization of color-emotion associations. In this study, we disentangle the contribution of lightness, chroma, and hue in color-happy/sad associations by controlling for lightness and chroma either statistically or colorimetrically. We found that after controlling for lightness and chroma, colors with blue hue were no sadder than colors with yellow hue, and in some cases, colors with blue hue were actually happier. These results can help guide future efforts to understand the nature of color-emotion associations.
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18
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Danilova MV, Mollon JD. Discrimination of hue angle and discrimination of colorimetric purity assessed with a common metric. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2020; 37:A226-A236. [PMID: 32400547 DOI: 10.1364/josaa.382382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 02/17/2020] [Indexed: 06/11/2023]
Abstract
It has been suggested that thresholds for discriminating colorimetric purity are systematically higher than those for discriminating hue angle, a difference captured in Judd's phrase "the super-importance of hue." However, to compare the two types of discrimination, the measured thresholds must be expressed in the same units. An attractive test is offered by measurements along the horizontal lines in the chromaticity diagram of MacLeod and Boynton [ J. Opt. Soc. Am.69, 1183 (1979)JOSAAH0030-394110.1364/JOSA.69.001183], i.e., a chromaticity diagram. A horizontal line that extends radially from the white point represents a variation in colorimetric purity alone (and subjectively a variation that is primarily in saturation). In contrast, a horizontal line that runs along the $x$x axis of the diagram, close to the long-wave spectrum locus, corresponds predominantly to variation in hue angle. Yet, in both cases, only the ratio of the excitations of the long- and middle-wave cones is being modulated, and so the thresholds can be expressed in a common metric. Measuring forced-choice thresholds for 180 ms foveal targets presented on a steady field metameric to Illuminant D65, we do not find general support for Judd's working rule that thresholds for purity are systematically twice those for saturation. Thresholds for colorimetric purity were only a little higher than those for hue angle, and the advantage for hue was seen in only part of the ranges that were tested. However, in the upper-left quadrant of the MacLeod-Boynton diagram, where the excitation of short-wave cones is high and where both hue angle and colorimetric purity vary along any given horizontal line, thresholds were indeed sometimes half those observed for discrimination of purity alone.
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19
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Honson V, Huynh-Thu Q, Arnison M, Monaghan D, Isherwood ZJ, Kim J. Effects of Shape, Roughness and Gloss on the Perceived Reflectance of Colored Surfaces. Front Psychol 2020; 11:485. [PMID: 32265792 PMCID: PMC7101081 DOI: 10.3389/fpsyg.2020.00485] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 03/02/2020] [Indexed: 11/13/2022] Open
Abstract
This study examined perceptual differentiation of specular from diffuse shading for the recovery of surface color and gloss. In Experiment 1, we parametrically varied the mesoscale relief height of globally planar surfaces, specular sharpness and the orientation of the surface relative to the light source. We obtained psychophysical matches for perceived color saturation and value (HSV), but also considered whether the main effects could be influenced by color space used when transforming data to perceptually-uniform CIE LCH space. Results revealed strong interactions between perceived color attributes and the lighting conditions, the structure of specular reflections, and surface relief. Declines in saturation were observed with increasing specular roughness (using an HSV color representation), but no similar decline was observed in chroma (using a CIE LCH color representation). Experiment 2 found strong negative correlations between perceived gloss and specular roughness. Perceived gloss also depended on mesoscopic relief height and orientation of the surface relative to the light source. Declines in perceived gloss moderately accounted for the variability in color saturation and value matches obtained in Experiment 1. We found information about perceived specular coverage could further improve the model's accountability of perceived color saturation and lightness (Experiment 3). These findings together suggest that perceived color saturation and color value depends on the visual system's ability to distinguish the underlying diffuse shading from specular highlights in images.
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Affiliation(s)
- Vanessa Honson
- Sensory Processes Research Laboratory, School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
| | - Quan Huynh-Thu
- Canon Information Systems Research Australia (CiSRA), Sydney, NSW, Australia
- Nearmap, Sydney, NSW, Australia
| | - Matthew Arnison
- Canon Information Systems Research Australia (CiSRA), Sydney, NSW, Australia
- Bandicoot Imaging Sciences, Sydney, NSW, Australia
| | - David Monaghan
- Canon Information Systems Research Australia (CiSRA), Sydney, NSW, Australia
- Bandicoot Imaging Sciences, Sydney, NSW, Australia
| | - Zoey J. Isherwood
- Sensory Processes Research Laboratory, School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
- School of Psychology, University of Wollongong, Wollongong, NSW, Australia
| | - Juno Kim
- Sensory Processes Research Laboratory, School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
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20
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Hardman A, Töllner T, Martinovic J. Neural differences between chromatic- and luminance-driven attentional salience in visual search. J Vis 2020; 20:5. [PMID: 32196068 PMCID: PMC7408945 DOI: 10.1167/jovi.20.3.5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Accepted: 11/28/2019] [Indexed: 12/02/2022] Open
Abstract
Previous electroencephalographic research on attentional salience did not fully capture the complexities of low-level vision, which relies on both cone-opponent chromatic and cone-additive luminance mechanisms. We systematically varied color and luminance contrast using a visual search task for a higher contrast target to assess the degree to which the salience-computing attentional mechanisms are constrained by low-level visual inputs. In our first experiment, stimuli were defined by contrast that isolated chromatic or luminance mechanisms. In our second experiment, targets were defined by contrasts that isolated or combined achromatic and chromatic mechanisms. In both experiments, event-related potential waveforms contralateral and ipsilateral to the target were qualitatively different for chromatic- compared to luminance-defined stimuli. The same was true of the difference waves computed from these waveforms, with isoluminant stimuli eliciting a mid-latency posterior contralateral negativity (PCN) component and achromatic stimuli eliciting a complex of multiple components, including an early posterior contralateral positivity followed by a late-latency PCN. Combining color with luminance resulted in waveform and difference wave patterns equivalent to those of achromatic stimuli. When large levels of chromaticity contrast were added to targets with small levels of luminance contrast, PCN latency was speeded. In conclusion, the mechanisms underlying attentional salience are constrained by the low-level inputs they receive. Furthermore, speeded PCN latencies for stimuli that combine color and luminance signals compared to stimuli that contain luminance alone demonstrate that color and luminance channels are integrated during pre-attentive visual processing, before top-down allocation of attention is triggered.
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Affiliation(s)
- Amanda Hardman
- School of Psychology, University of Aberdeen, Aberdeen, UK
| | - Thomas Töllner
- Department of Experimental Psychology, Ludwig-Maximilians-University Munich, Munich, Germany
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21
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Witzel C, Maule J, Franklin A. Red, yellow, green, and blue are not particularly colorful. J Vis 2019; 19:27. [DOI: 10.1167/19.14.27] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Christoph Witzel
- Experimental Psychology, Justus-Liebig-University, Gießen, Germany
- ://www.allpsych.uni-giessen.de/chris/
| | - John Maule
- School of Psychology, University of Sussex, Brighton, UK
- ://www.sussex.ac.uk/profiles/201831
| | - Anna Franklin
- School of Psychology, University of Sussex, Brighton, UK
- ://www.sussex.ac.uk/profiles/256540
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22
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Haigh SM, Chamanzar A, Grover P, Behrmann M. Cortical Hyper‐Excitability in Migraine in Response to Chromatic Patterns. Headache 2019; 59:1773-1787. [DOI: 10.1111/head.13620] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Sarah M. Haigh
- Department of Psychology, Institute for Neuroscience University of Nevada Reno NV USA
- Department of Psychology, Center for the Neural Basis of Cognition Carnegie Mellon University Pittsburgh PA USA
| | - Alireza Chamanzar
- Department of Electrical and Computer Engineering Carnegie Mellon University Pittsburgh PA USA
| | - Pulkit Grover
- Department of Electrical and Computer Engineering Carnegie Mellon University Pittsburgh PA USA
| | - Marlene Behrmann
- Department of Psychology, Center for the Neural Basis of Cognition Carnegie Mellon University Pittsburgh PA USA
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23
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Conway BR, Eskew RT, Martin PR, Stockman A. A tour of contemporary color vision research. Vision Res 2018; 151:2-6. [PMID: 29959956 PMCID: PMC6345392 DOI: 10.1016/j.visres.2018.06.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 06/12/2018] [Accepted: 06/23/2018] [Indexed: 11/17/2022]
Abstract
The study of color vision encompasses many disciplines, including art, biochemistry, biophysics, brain imaging, cognitive neuroscience, color preferences, colorimetry, computer modelling, design, electrophysiology, language and cognition, molecular genetics, neuroscience, physiological optics, psychophysics and physiological optics. Coupled with the elusive nature of the subjective experience of color, this wide range of disciplines makes the study of color as challenging as it is fascinating. This overview of the special issue Color: Cone Opponency and Beyond outlines the state of the science of color, and points to some of the many questions that remain to be answered in this exciting field.
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Affiliation(s)
- Bevil R Conway
- National Eye Institute and National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rhea T Eskew
- Department of Psychology, 125 Nightingale Hall, Northeastern University, Boston, MA 02115, USA
| | - Paul R Martin
- Save Sight Institute and School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Andrew Stockman
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, England, United Kingdom
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Abstract
Color has been scientifically investigated by linking color appearance to colorimetric measurements of the light that enters the eye. However, the main purpose of color perception is not to determine the properties of incident light, but to aid the visual perception of objects and materials in our environment. We review the state of the art on object colors, color constancy, and color categories to gain insight into the functional aspects of color perception. The common ground between these areas of research is that color appearance is tightly linked to the identification of objects and materials and the communication across observers. In conclusion, we argue that research should focus on how color processing is adapted to the surface properties of objects in the natural environment in order to bridge the gap between the known early stages of color perception and the subjective appearance of color.
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Affiliation(s)
- Christoph Witzel
- Department of Psychology, University of Giessen, 35394 Giessen, Germany;,
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25
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Martinovic J, Andersen SK. Cortical summation and attentional modulation of combined chromatic and luminance signals. Neuroimage 2018; 176:390-403. [PMID: 29730493 DOI: 10.1016/j.neuroimage.2018.04.066] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 04/05/2018] [Accepted: 04/28/2018] [Indexed: 11/26/2022] Open
Abstract
Cortical networks that process colour and luminance signals are often studied separately, although colour appearance depends on both colour and luminance. In fact, objects in everyday life are very rarely defined by only colour or only luminance, necessitating an investigation into combined processing of these signals. We used steady-state visual evoked potentials (SSVEPs) to investigate (1) cortical summation of luminance and chromatic contrast and (2) attentional modulation of neural activity driven by competing stimuli that differ in chromoluminant content. Our stimuli combined fixed amounts of chromatic contrast from either of the two cone-opponent mechanisms (bluish and yellowish; reddish and greenish) with two different levels of positive luminance contrast. Our experiments found evidence of non-linear processing of combined colour and luminance signals, which most likely originates in V1-V3 neurons tuned to both colour and luminance. Differences between luminance contrast of stimuli were found to be a key determinant for the size of feature-based voluntary attentional effects in SSVEPs, with colours of lower contrast than the colour they were presented with receiving the highest level of attentional modulation. Our results indicate that colour and luminance contrast are processed interdependently, both in terms of perception and in terms of attentional selection, with a potential candidate mediating their link being stimulus appearance, which depends on both chromaticity and luminance.
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