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Color contrast sensitivity

Kazumichi Matsumiya, Masayuki Sato, Satoshi Shioiri
Two phenomena have been reported to affect the perceived displacement of a visual target during saccadic eye movements: the blanking effect and landmark effect. In the blanking effect, temporarily blanking the target after a saccade improves displacement judgments. In the landmark effect, illusory target displacement occurs when a continuously presented landmark is displaced during a saccade, and the target is temporarily blanked after the saccade without displacement. We show that the strengths of the blanking and landmark effects vary with stimulus contrast...
October 20, 2016: Vision Research
N Platz Batista da Silva, M Schauer, M Hornung, S Lang, L P Beyer, I Wiesinger, C Stroszczynski, E M Jung
OBJECTIVE: To evaluate the efficacy of strain elastography (SE) using semi-quantitative measurement methods compared to constrast enhanced ultrasound during liver tumor surgery (Io-CEUS) for dignity assessment of focal liver lesions(FLL). MATERIAL AND METHODS: Prospective data acquisition and retrospective analysis of US data of 100 patients (116 lesions) who underwent liver tumor surgery between 10/2010 and 03/2016. Retrospective reading of SE color patterns was performed establishing groups depending on dominant color (>50% blue = stiff, inhomogenous, >50% yellow/red/green = soft tissue)...
October 20, 2016: Clinical Hemorheology and Microcirculation
A Ridder, M L T M Müller, V Kotagal, K A Frey, R L Albin, N I Bohnen
OBJECTIVES: Dopaminergic degeneration affects both nigrostriatal projection neurons and retinal amacrine cells in Parkinson disease (PD). Parkinsonian retinopathy is associated with impaired color discrimination and contrast sensitivity. Some prior studies described associations between color discrimination deficits and cognitive deficits in PD, suggesting that contrast discrimination deficits are due, at least in part, to cognitive deficits in PD. We investigated the relationship between cognitive deficits and impaired contrast sensitivity in PD...
October 7, 2016: Parkinsonism & related Disorders
Benjamin Gagl
BACKGROUND: Highlighted text in the Internet (i.e., hypertext) is predominantly blue and underlined. The perceptibility of these hypertext characteristics was heavily questioned by applied research and empirical tests resulted in inconclusive results. The ability to recognize blue text in foveal and parafoveal vision was identified as potentially constrained by the low number of foveally centered blue light sensitive retinal cells. The present study investigates if foveal and parafoveal perceptibility of blue hypertext is reduced in comparison to normal black text during reading...
2016: PeerJ
Jonathan S Cant, Yaoda Xu
Our visual system can extract summary statistics from large collections of objects without forming detailed representations of the individual objects in the ensemble. In a region in ventral visual cortex encompassing the collateral sulcus and the parahippocampal gyrus and overlapping extensively with the scene-selective parahippocampal place area (PPA), we have previously reported fMRI adaptation to object ensembles when ensemble statistics repeated, even when local image features differed across images (e...
September 27, 2016: Journal of Cognitive Neuroscience
Vito Cantisani, Emanuele David, Donatella Ferrari, Fabrizio Fanelli, Luca Di Marzo, Carlo Catalano, Filippo Benedetto, Domenico Spinelli, Athanasios Katsargyris, Alfredo Blandino, Giorgio Ascenti, Ferdinando D'Ambrosio
OBJECTIVE: To evaluate the diagnostic effectiveness of color-Doppler ultrasound with Superb Microvascular Imaging (SMI) compared to ultrasound with contrast agent (CEUS), CT multi-slice angiography (64 slices) and angiography required for therapeutic reasons, for follow-up after endovascular aneurysm repair (EVAR) MATERIALS AND METHODS: from March 2014 to May 2015, 57 patients treated with EVAR were evaluated with CT, CEUS, CDUS, SMI and angiography in cases requiring treatment. Evaluation included sac diameter, stent-graft integrity, identification and classification of endoleaks...
September 23, 2016: Annals of Vascular Surgery
Xiaotian Sun, Tenghui Dong, Yiliang Bi, Min Min, Wei Shen, Yang Xu, Yan Liu
Endoscopy has been widely used in diagnosing gastrointestinal mucosal lesions. However, there are still lack of objective endoscopic criteria. Linked color imaging (LCI) is newly developed endoscopic technique which enhances color contrast. Thus, we investigated the clinical application of LCI and further analyzed pixel brightness for RGB color model. All the lesions were observed by white light endoscopy (WLE), LCI and blue laser imaging (BLI). Matlab software was used to calculate pixel brightness for red (R), green (G) and blue color (B)...
2016: Scientific Reports
Anja Kraneburg, Steffen Franke, Ralf Methling, Barbara Griefahn
UNLABELLED: We studied the influence of correlated color temperature (CCT) of 7 polychromatic white light illuminations (1600 K-14,000 K, 200 lx) in two experiments. Visual performance was tested in 17 students (8 men) during daytime. Visual acuity, contrast sensitivity and sleepiness did not vary with illuminations but polychromatic white light of <2000 K impaired color discrimination. Melatonin synthesis was tested with weekly intervals in 8 trials from 10pm to 2am (7 polychromatic illuminations and a dim light reference (<0...
January 2017: Applied Ergonomics
Euphemia W Mu, Jesse M Lewin, Mary L Stevenson, Shane A Meehan, John A Carucci, Daniel S Gareau
Importance: Confocal microscopy has the potential to provide rapid bedside pathologic analysis, but clinical adoption has been limited in part by the need for physician retraining to interpret grayscale images. Digitally stained confocal mosaics (DSCMs) mimic the colors of routine histologic specimens and may increase adaptability of this technology. Objective: To evaluate the accuracy and precision of 3 physicians using DSCMs before and after training to detect basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) in Mohs micrographic surgery fresh-tissue specimens...
September 7, 2016: JAMA Dermatology
Kaitlin S Bohon, Katherine L Hermann, Thorsten Hansen, Bevil R Conway
The lateral geniculate nucleus is thought to represent color using two populations of cone-opponent neurons [L vs M; S vs (L + M)], which establish the cardinal directions in color space (reddish vs cyan; lavender vs lime). How is this representation transformed to bring about color perception? Prior work implicates populations of glob cells in posterior inferior temporal cortex (PIT; the V4 complex), but the correspondence between the neural representation of color in PIT/V4 complex and the organization of perceptual color space is unclear...
July 2016: ENeuro
Mindaugas Mitkus, Gabrielle A Nevitt, Johannis Danielsen, Almut Kelber
Procellariiform or 'tubenosed' seabirds are challenged to find prey and orient over the seemingly featureless oceans. Previous studies have found that life history strategy (burrow vs. surface nesting) was correlated to foraging strategy. Burrow nesters tended to track prey using dimethyl sulphide (DMS), a compound associated with phytoplankton, whereas surface-nesting species did not. Burrow nesters also tended to be smaller and more cryptic, whereas surface nesters were larger with contrasting plumage coloration...
September 2, 2016: Journal of Experimental Biology
Jeff Rabin, Brook Houser, Carolyn Talbert, Ruh Patel
PURPOSE: In Feb 2015 an image of a dress posted on Tumblr triggered an internet phenomenon: Is the Dress blue and black (BB) or white and gold (WG)? Many claim BB and others insist WG while the true colors are BB. The prevailing theory is that assumptions about the illuminant govern perception of the Dress with WG due to bluish lighting and BB due to yellowish. Our purpose was to determine if early stage optical, retinal and/or neural factors also impact perception of the Dress. METHODS: Thirty-nine subjects were categorized as BB or WG based on their initial perception of the Dress and their perception reported when viewing the Dress on iPhone 5, iPad, and 22" LCD displays...
2016: PloS One
Baisheng Dai, Xiangqian Wu, Wei Bu
Retinal microaneurysms (MAs) are the earliest clinically observable lesions of diabetic retinopathy. Reliable automated MAs detection is thus critical for early diagnosis of diabetic retinopathy. This paper proposes a novel method for the automated MAs detection in color fundus images based on gradient vector analysis and class imbalance classification, which is composed of two stages, i.e. candidate MAs extraction and classification. In the first stage, a candidate MAs extraction algorithm is devised by analyzing the gradient field of the image, in which a multi-scale log condition number map is computed based on the gradient vectors for vessel removal, and then the candidate MAs are localized according to the second order directional derivatives computed in different directions...
2016: PloS One
Xiao-Yun Xiao, Xin Chen, Xiao-Feng Guan, Huan Wu, Wei Qin, Bao-Ming Luo
OBJECTIVE: To evaluate the diagnostic performance of superb microvascular imaging (SMI) in breast lesions, comparing with contrast-enhanced ultrasonographic microvascular imaging (MVI). METHODS: From April to November 2015, 132 patients (with 132 breast lesions) were enrolled in the retrospective study. All lesions were evaluated with colour Doppler flow imaging (CDFI), colour SMI (cSMI), monochrome SMI (mSMI) and contrast-enhanced ultrasonographic MVI. Receiver-operating characteristic curve analysis was performed to compare the diagnostic performance of SMI and MVI for discrimination between benign and malignant breast lesions...
October 2016: British Journal of Radiology
Mimi Kim, Kyung Mi Jang, Jae-Hun Kim, Woo Kyoung Jeong, Seong Hyun Kim, Tae Wook Kang, Young Kon Kim, Dong Ik Cha, Kyunga Kim
OBJECTIVES: To evaluate the value of dynamic enhancement patterns on contrast-enhanced MR images by adding signal intensity colour mapping (SICM) to differentiate mass-forming focal pancreatitis (MFFP) from pancreatic ductal adenocarcinoma (PDAC). METHODS: Forty-one clinicopathologically proven MFFPs and 144 surgically confirmed PDACs were enrolled. Laboratory and MR imaging parameters were used to differentiate MFFP from PDAC. In particular, enhancement patterns on MR images adding SICM were evaluated...
August 10, 2016: European Radiology
Eric C Ehman, Andrew S Phelps, Michael A Ohliger, Sue J Rhee, John D MacKenzie, Jesse L Courtier
PURPOSE: To evaluate the fused, colorized diffusion weighted imaging (DWI) and anatomic T2 images compared to routine contrast-enhanced T1 images at pediatric magnetic resonance enterography (MRE). METHODS: Fused, colorized DWI/T2 images were created from patients with magnetic resonance enterography (MRE) and colonoscopy/biopsy. Radiologists noted inflammation in five bowel segments (terminal ileum-rectosigmoid colon) on postcontrast images and DWI/T2 images. Test characteristics and agreement were calculated...
July 21, 2016: Clinical Imaging
Maria M Del Viva, Giovanni Punzi, Steven K Shevell
The visual system is able to recognize a scene based on a sketch made of very simple features. This ability is likely crucial for survival, when fast image recognition is necessary, and it is believed that a primal sketch is extracted very early in the visual processing. Such highly simplified representations can be sufficient for accurate object discrimination, but an open question is the role played by color in this process. Rich color information is available in natural scenes, yet artist's sketches are usually monochromatic; and, black-and-white movies provide compelling representations of real world scenes...
2016: PloS One
Girena Slatkeviciene, Rasa Liutkeviciene, Brigita Glebauskiene, Dalia Zaliuniene, Loresa Kriauciuniene, Giedrimantas Bernotas, Arimantas Tamasauskas
PURPOSE: Our objective was to estimate the maximum color contrast sensitivity (MCCS) thresholds in individuals with chiasma opticum damage. METHODS: The pilot study tested 41 people with pituitary adenoma (PA) and 100 age- and gender-matched controls. Patients were divided into two groups according to PA size, PA ≤1 cm or PA >1 cm. A new MCCS test program was used for color discrimination. RESULTS: The mean total error score (TES) of MCCS was 1...
August 2016: Korean Journal of Ophthalmology: KJO
Timothy G Shepard, Emily A Swanson, Comfrey L McCarthy, Rhea T Eskew
Narrowly tuned, selective noise masking of chromatic detection has been taken as evidence for the existence of a large number of color mechanisms (i.e., higher order color mechanisms). Here we replicate earlier observations of selective masking of tests in the (L,M) plane of cone space when the noise is placed near the corners of the detection contour. We used unipolar Gaussian blob tests with three different noise color directions, and we show that there are substantial asymmetries in the detection contours-asymmetries that would have been missed with bipolar tests such as Gabor patches...
July 1, 2016: Journal of Vision
Jeffrey S Phillips, Corey T McMillan, Edward E Smith, Murray Grossman
Semantic category learning is dependent upon several factors, including the nature of the learning task, as well as individual differences in the quality and heterogeneity of exemplars that an individual encounters during learning. We trained healthy older adults (n=39) and individuals with a diagnosis of Alzheimer's disease or Mild Cognitive Impairment (n=44) to recognize instances of a fictitious animal, a "crutter". Each stimulus item contained 10 visual features (e.g., color, tail shape) which took one of two values for each feature (e...
July 6, 2016: Neuropsychologia
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