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visual perception alterations in COVID-19:a preliminary study

International Journal of Ophthalmology(English edition) 2023年第1期16卷 1-9页

作者： María Begoña Coco-Martín Luis Leal-Vega Irene Alcoceba-Herrero Ainhoa Molina-Martín Dolores de-Fez María JoséLuque Carlos Dueñas-Gutiérrez Juan Francisco Arenillas-Lara David PPiñero Group of Applied Clinical Neurosciences and Advanced Data Analysis Department of MedicineDermatology and ToxicologyUniversity of ValladolidValladolid 47005Spain Group of Optics and visual perception Department of OpticsPharmacology and AnatomyUniversity of AlicanteAlicante 03690Spain Department of Optics and Optometry and Vision SciencesUniversity of ValenciaValencia 46100Spain COVID-19 Unit Department of Internal MedicineUniversity Clinical Hospital of ValladolidValladolid 47003Spain Stroke Unit Department of NeurologyUniversity Clinical Hospital of ValladolidValladolid 47003Spain Clinical Optometry Unit Department of OphthalmologyVithas Medimar International HospitalAlicante 03016Spain

AIM:To compare the visual perception(color and chromatic-achromatic contrast vision)of a small cohort of COVID-19 patients at the time of infection and after 6mo with that of a healthy population matched for sex and age.METHODS:A total of 25 patients(9 females,16 males,mean age:54±10y)with COVID-19 hospitalized in the COVID-19 Unit of the University Clinical Hospital of Valladolid were recruited for this preliminary study.visual perception,as determined by monocular measurement of contrast sensitivity function(CSF)and color vision was assessed in each patient using the Optopad test.The results obtained were then compared with those of a sample of 16 age-and sex-matched healthy controls(5 females,11 males,mean age:50±6y)in which the same measurement procedure was repeated.Statistically significant differences between groups were assessed using the Mann-Whitney U test.Measurements were repeated after a minimum follow-up period of 6mo and statistically significant differences between the two time points in each group were assessed using the Wilcoxon signed rank test.RESULTS:Discrimination thresholds(color and chromatic-achromatic contrast vision)and their corresponding sensitivity,calculated as the inverse of the discrimination threshold,were evaluated.Analysis of the data revealed higher contrast threshold results(i.e.,worse contrast sensitivity)in the COVID-19 group than in the control group for all spatial frequencies studied in the Optopad-CSF achromatic test and most of the spatial frequencies studied in the Optopad-CSF chromatic test for the red-green and blue-yellow mechanisms.In addition,color threshold results in the COVID-19 group were also significantly higher(i.e.,worse color sensitivity)for almost all color mechanisms studied in the Optopad-Color test.At 6mo,most of the differences found between the groups were maintained despite COVID-19 recovery.CONCLUSION:The present results provide preliminary evidence that visual perception may be impaired in COVID-19,even when the infection has passed.Although fur

关键词： SARS-CoV-2 COVID-19 visual perception contrast sensitivity function color vision

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visual perception on the architectural elements of the built heritage of a historic temple town： A case study of Kumbakonam, India

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Frontiers of Architectural Research 2017年第1期6卷 96-107页

作者： K. Kiruthisa K. Thirumaran Department of Architecture National Institute of Technology Tiruchirappalli Tamilnadu 620015 India

This paper aims to investigate the changes in the virtual perception on the built heritage at the traditional core setttement of Kumbakonam Town at Tamitnadu and to analyze their implica- tions. Specifically, the major objectives of the study are （1） to identify the architectural elements that manifest the built heritage of Kumbakonam Town and （2） to assess the contMbutions of these elements to the changes in the visuat perception of the town. To achieve these objectives, this study adopts an empirical model that analyzes the architectural elements of the buildings in the study area. Direct observations and documentations of 373 buildings are collected to analyze those etements that contribute to the changes in the visual perception on the built heritage of Kumbakonam Town. An ordinary regression model is used to examine the characteristics of the built heritage across the chariot processional route of the town. Several architectural elements, including pitasters, horizontal cornices, arched windows, and ornamental parapets, improve the image of the town. These empirical findings support the policy framework that enhances the visual perception of Kumbakonam Town.

关键词： visual perception Built heritage Ordinal regression Architectural ele-ments Historic town

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通过深度神经网络与皮层网络的多级整合增强自然感知的神经编码模型

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Science Bulletin 2024年第11期69卷 1738-1747页

作者：李远宁杨虎铮顾实 School of Biomedical Engineering&State Key Laboratory of Advanced Medical Materials and Devices ShanghaiTech UniversityShanghai 201210China School of Computer Science and Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Department of Computer and Information Science University of PennsylvaniaPhiladelphiaPA 19104USA Shenzhen Institute for Advanced Study University of Electronic Science and Technology of ChinaShenzhen 518110China

Cognitive neuroscience aims to develop computational models that can accurately predict and explain neural responses to sensory inputs in the cortex. Recent studies attempt to leverage the representation power of deep neural networks(DNNs) to predict the brain response and suggest a correspondence between artificial and biological neural networks in their feature representations. However, typical voxel-wise encoding models tend to rely on specific networks designed for computer vision tasks, leading to suboptimal brain-wide correspondence during cognitive tasks. To address this challenge, this work proposes a novel approach that upgrades voxel-wise encoding models through multi-level integration of features from DNNs and information from brain networks. Our approach combines DNN feature-level ensemble learning and brain atlas-level model integration, resulting in significant improvements in predicting whole-brain neural activity during naturalistic video perception. Furthermore, this multi-level integration framework enables a deeper understanding of the brain's neural representation mechanism, accurately predicting the neural response to complex visual concepts. We demonstrate that neural encoding models can be optimized by leveraging a framework that integrates both data-driven approaches and theoretical insights into the functional structure of the cortical networks.

关键词： Neural encoding visual perception Artificial neural networks Functional neuroimaging Naturalistic stimuli

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MF-CFI:A fused evaluation index for camouflage patterns based on human visual perception

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Defence Technology（防务技术） 2021年第5期17卷 1602-1608页

作者： Xin Yang Wei-dong Xu Qi Jia Jun Liu National Key Laboratory of Lightning Protection and Electromagnetic Camouflage Army Engineering UniversityNanjingJiangsu210007China

The evaluation index of camouflage patterns is important in the field of military application.It is the goal that researchers have always pursued to make the computable evaluation indicators more in line with the human visual mechanism.In order to make the evaluation method more computationally intelligent,a Multi-Feature Camouflage Fused Index(MF-CFI)is proposed based on the comparison of grayscale,color and texture features between the target and the background.In order to verify the effectiveness of the proposed index,eye movement experiments are conducted to compare the proposed index with existing indexes including Universal Image Quality Index(UIQI),Camouflage Similarity Index(CSI)and Structural Similarity(SSIM).Twenty-four different simulated targets are designed in a grassland background,28 observers participate in the experiment and record the eye movement data during the observation process.The results show that the highest Pearson correlation coefficient is observed between MF-CFI and the eye movement data,both in the designed digital camouflage patterns and largespot camouflage patterns.Since MF-CFI is more in line with the detection law of camouflage targets in human visual perception,the proposed index can be used for the comparison and parameter optimization of camouflage design algorithms.

关键词： Camouflage evaluation visual perception Effect assessment Fused index Eye movement analysis

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Photonic synapses with ultralow energy consumption for artificial visual perception and brain storage

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Opto-Electronic Advances 2022年第9期5卷 1-13页

作者： Caihong Li Wen Du Yixuan Huang Jihua Zou Lingzhi Luo Song Sun Alexander OGovorov Jiang Wu Hongxing Xu Zhiming Wang Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China Microsystem and Terahertz Research Center China Academy of Engineering PhysicsChengdu 610200China Institute of Electronic Engineering China Academy of Engineering PhysicsMianyang 621999China Department of Physics and Astronomy Ohio UniversityAthensOhio 45701United States State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of ChinaChengdu 610065China School of Physics and Technology Wuhan UniversityWuhan 430072China

The human visual system,dependent on retinal cells,can be regarded as a complex combination of optical system and nervous system.Artificial retinal system could mimic the sensing and processing function of human eyes.Optically stimulated synaptic devices could serve as the building blocks for artificial retinas and subsequent information transmission system to brain.Herein,photonic synaptic transistors based on polycrystalline MoS_(2),which could simulate human visual perception and brain storage,are presented.Moreover,the photodetection range from visible light to near-infrared light of MoS_(2) multilayer could extend human eyes’vision limitation to near-infrared light.Additionally,the photonic synaptic transistor shows an ultrafast speed within 5μs and ultralow power consumption under optical stimuli about 40 aJ,several orders of magnitude lower than biological synapses(50 ms and 10 fJ).Furthermore,the backgate control could act as emotional modulation of the artificial brain to enhance or suppress memory function,i.***.the intensity of photoresponse.The proposed carrier trapping/detrapping as the main working mechanism is presented for the device.In addition,synaptic functionalities including short synaptic plasticity,long synaptic plasticity and paired-pulse facilitation could be successfully simulated based on the prepared device.Furthermore,the large difference between short synaptic plasticity and long synaptic plasticity reveals the better image pre-processing function of the prepared photonic synapses.The classical Pavlovian conditioning associated with the associative learning is successfully implemented as well.Therefore,the efficient and rich functionalities demonstrate the potential of the MoS_(2) synaptic device that integrates sensing-memory-preprocessing capabilities for realizing artificial neural networks with different emotions that mimic human retina and brain.

关键词： MoS_(2)synaptic transistors visual perception ultralow power consumption memory

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Real-time information recombination of complex 3D tree model based on visual perception

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Science China(Information Sciences) 2013年第9期56卷 96-109页

作者： FAN Jing FAN YunYi DONG TianYang JI Lei School of Computer Science and Technology Zhejiang University of Technology

It is important for the rapid visualization of large scale forest scene to dynamically simplify and recombine model data. In order to preserve the geometric features and visual perception of tree model, this paper presents a real-time information recombination method of complex 3D tree model based on visual perception. This method adopts visual attention model and the visual characteristic of tree structures, and then uses geometry-based and image-based methods to simplify tree models and construct a hybrid representation model. The hybrid representation model reflects the visual perception features of 3D tree models that can embody topological semantics in dynamic simulation. In addition, this method automatically extracts the representation information of 3D tree model based on visual perception, and recombines model information in real time according to the dynamic viewpoint of virtual scene. Finally, this method is applied in the simplification of different tree models, and it is compared with the existing tree model simplification methods. Experimental results show that this method can not only preserve better visual perception for 3D tree models, but also effectively decrease the geometric data of forest scene, and improve the rendering efficiency of forest scene.

关键词： visual perception model simplification 3D tree real-time recombination hybrid representation

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Achieving the visual perception and Gestalt Psychology in Sultan Hassan Mosque Building

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Open Journal of Applied Sciences 2021年第1期11卷 21-40页

作者： Essam Metwally Department of Interior Design Faculty of Architecture and Design American University of Madaba Amman Jordan

The gestalt principles are perception and what is visually communicated by objects. These principles describe the visual language within which we work. Understanding how a designer realizes things visually will help designers communicate better. Many designers use Gestalt principles to have a structure visual stimulus, so as to create interfaces that are easy for users to understand. Because the understanding of visual perception is a critical item in any designer’s toolkit. Islamic heritage buildings also contain many architectural values, especially the Sultan Hassan Mosque in Cairo. Through this paper, we will verify the use of gestalt principles of visual perception in the building design. Because the psychological organization of the design, achieves the understanding and awareness of the current relationships between the elements, depending on the extent of regularity, accuracy, and consistency of the design elements. This makes us recognize the esthetic values of Sultan Hassan’s building and mosque. The visual delight we get from architecture begins with how we perceive it. So, in order to understand how visual delight arises, we must first understand how we perceive and interpret visual stimuli. Especially since the principles of gestalt confirm that the human brain tends to make tricks and illusions. Therefore, we found the mosque designer had exploited this fact during the design process, to exclude any possibility of the resulting misunderstanding. The designer achieved the psychological preparation of the visitor by using some principles of visual perception of the Gestalt theory, such as growth, continuity, and hierarchy.

关键词： Gestalt Principles visual perception Psychological Organization Esthetic Values Islamic Heritage Buildings

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The Color of Natural Teeth Investigated by visual perception and Spectrophotometer

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Open Journal of Stomatology 2015年第2期5卷 26-35页

作者： Teuta Pustina-Krasniqi Ariana Bytyci Teuta Bicaj Enis Ahmedi Linda Dula Zana Lila Arlinda Dragusha Nexhmije Ajeti Department of Prosthetic Dentistry Dental BranchMedical FacultyUniversity of PrishtinaPrishtinaKosovo Private Dental Office PrishtinaKosovo Department of Endodontic and Dental Pathology Dental BranchMedical FacultyUniversity of PrishtinaPrishtinaKosovo

The advantage of electronic devices is to eliminate the subjectivity. Based on individual capabilities, visual perception has its disadvantages. The aim of this study was to find out the possible shade difference between the upper and lower teeth, visual perception versus spectrophotometry as well as proving that females are better in visual perception of colour matching. 82 subjects (dental students) of this study determined the color of each other’s natural teeth. The color of 1640 teeth (incisors, canines and premolars), was matched by visual perception and by Vita Easyshade spectrophotometer. The matching was focused on the middle third of buccal surfaces of the examined teeth. In this study, it was found that there was a difference of color between the teeth of the upper and lower jaw. The percentage of the accordance between two methods was 28.35% for all examined teeth. The color determination at central incisors showed the highest value of accordance 40.85%. Based on Vitapan 3D Mastershade, the most frequent color was 2M2.

关键词： Teeth Color visual perception Spectrophotometer Accordance

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Effects of visual restoration on gait performance and kinematics of lower extremities in patients with age-related cataract

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Chinese Medical Journal 2023年第5期136卷 596-603页

作者： Mingxin Ao Huijuan Shi Xuemin Li Hongshi Huang Yingfang Ao Wei Wang Department of Ophthalmology Beijing Key Laboratory of Restoration of Damaged Ocular NervePeking University Third HospitalBeijing 100191China Department of Sports Medicine Institute of Sports Medicine of Peking UniversityBeijing Key Laboratory of Sports InjuriesPeking University Third HospitalBeijing 100191China.

Background:visual inputs are critical for locomotor navigation and sensorimotor integration in the elderly;however,the mechanism needs to be explored intensively.The present study assessed the gait pattern after cataract surgery to investigate the effects of visual restoration on locomotion.Methods:The prospective study recruited 32 patients(70.1±5.2 years)with bilateral age-related cataracts in the Department of Ophthalmology at Peking University Third Hospital from October 2016 to December 2019.The temporal-spatial gait parameters and kinematic parameters were measured by the Footscan system and inertial measurement units.Paired t-test was employed to compare data normally distributed and Wilcoxon rank-sum test for non-normally distributed.Results:After visual restoration,the walking speed increased by 9.3%(1.19±0.40 m/s vs.1.09±0.34 m/s,P=0.008)and exhibited an efficient gait pattern with significant decrease in gait cycle(1.02±0.08 s vs.1.04±0.07 s,P=0.012),stance time(0.66±0.06 s vs.0.68±0.06 s,P=0.045),and single support time(0.36±0.03 s vs.0.37±0.02 s,P=0.011).High amplitude of joint motion was detected in the sagittal plane in the left hip(37.6°±5.3°vs.35.5°±6.2°,P=0.014),left thigh(38.0°±5.2°vs.36.4°±5.8°,P=0.026),left shank(71.9°±5.7°vs.70.1°±5.6°,P=0.031),and right knee(59.1°±4.8°vs.56.4°±4.8°,P=0.001).The motor symmetry of thigh improved from 8.35±5.30%to 6.30±4.73%(P=0.042).Conclusions:The accelerated gait in response to visual restoration is characterized by decreased stance time and increased range of joint motion.Training programs for improving muscle strength of lower extremities might be helpful to facilitate the adaptation to these changes in gait.

关键词： Biomechanical phenomena Cataract Gait Rehabilitation visual perception

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Adaptive Reversible Visible Watermarking Based on Total Variation for BTC-Compressed Images

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Computers, Materials & Continua 2023年第3期74卷 5173-5189页

作者： Hengfu Yang Mingfang Jiang Zhichen Gao School of Computer Science Hunan First Normal UniversityChangsha410205China Hunan Provincial Key Laboratory of Informationization Technology for Basic Education Changsha410205China Department of Applied Mathematics and Statistics College of Engineering and Applied SciencesStony Brook UniversityNY 11794USA

Few previous Reversible Visible Watermarking(RVW)schemes have both good transparency and watermark visibility.An adaptive RVW scheme that integrates Total Variation and visual perception in Block Truncation Coding(BTC)compressed domain,called TVB-RVW is proposed in this paper.A new mean image estimation method for BTC-compressed images is first developed with the help of Total Variation.Then,a visual perception factor computation model is devised by fusing texture and luminance characteristics.An adaptive watermark embedding strategy is used to embed the visible watermark with the effect of the visual perception factor in the BTC domain.Moreover,a lossless embedding method of the encrypted visible watermark is exploited to deter illegal watermark removal.The visible watermark can be removed since the visual perception factor and the estimated mean image remain unchanged before and after watermark embedding.Extensive experiments validate the superiority of the proposed algorithm over previous RVW schemes in BTC in terms of the visual quality of watermarked images and watermark visibility,and it can achieve a good balance between transparency and watermark visibility.

关键词： Reversible visible watermark block truncation coding visual perception total variation

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