14 research outputs found

    Non-rigidity induced by luminance gratings in structure-from-motion displays

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    An illusory motion between the brightest and darkest strips of luminance gratings used as texture over a slanted plane and rotating around a vertical axis was observed. This effect could not be expected from the theoretical analysis of structure-from-motion displays. The conditions for the perceived non-rigidity produced by the luminance gratings were evaluated in Experiment 1.  The results showed that the symmetry of the luminance profile, the slant of the planes and the motion direction modified the perceived orientation only of the brightest stripes. The effect is not due to the interpretation of the brightness variation of the moving gratings as caused by a stationary light source (Experiment 2) or by motion sharpening of the blurred edges in the gratings (Experiment 3). Potential explanations of the observed effect based on interaction between the processes of brightness filling-in and the motion information processing are discussed.Durant la rotation d’un plan oblique autour d’un axe vertical un mouvement illusoire est observé entre les bandes claires et sombres d’une grille lumineuse utilisée comme texture.  Un tel effet ne pouvait être prévu par l’analyse théorique de l’établissement de la structure à partir du mouvement. Les conditions pour cette non-rigidité perçue, produite par grilles lumineuses sont examinées dans la première étude.  Les résultats montrent que la symétrie du profile lumineux, la pente des plans et la direction du mouvement modifient l’orientation perçue uniquement des plus claires bandes. L’effet n’est pas dû à l’interprétation des bandes claires des grilles mouvantes comme dans le cas de source lumineuse stationnaire (Etude 2) ou dans celui de l’augmentation de la netteté du mouvement du flou des bords de la grille perçues (Expérimente 3). Des explications alternatives de l’effet observé sont discutées, basées sur les interactions entre les processus du remplissage de la luminosité et du mouvement

    Non-rigidity induced by luminance gratings in structure-from-motion displays

    Get PDF
    An illusory motion between the brightest and darkest strips of luminance gratings used as texture over a slanted plane and rotating around a vertical axis was observed. This effect could not be expected from the theoretical analysis of structure-from-motion displays. The conditions for the perceived non-rigidity produced by the luminance gratings were evaluated in Experiment 1.  The results showed that the symmetry of the luminance profile, the slant of the planes and the motion direction modified the perceived orientation only of the brightest stripes. The effect is not due to the interpretation of the brightness variation of the moving gratings as caused by a stationary light source (Experiment 2) or by motion sharpening of the blurred edges in the gratings (Experiment 3). Potential explanations of the observed effect based on interaction between the processes of brightness filling-in and the motion information processing are discussed.Durant la rotation d’un plan oblique autour d’un axe vertical un mouvement illusoire est observé entre les bandes claires et sombres d’une grille lumineuse utilisée comme texture.  Un tel effet ne pouvait être prévu par l’analyse théorique de l’établissement de la structure à partir du mouvement. Les conditions pour cette non-rigidité perçue, produite par grilles lumineuses sont examinées dans la première étude.  Les résultats montrent que la symétrie du profile lumineux, la pente des plans et la direction du mouvement modifient l’orientation perçue uniquement des plus claires bandes. L’effet n’est pas dû à l’interprétation des bandes claires des grilles mouvantes comme dans le cas de source lumineuse stationnaire (Etude 2) ou dans celui de l’augmentation de la netteté du mouvement du flou des bords de la grille perçues (Expérimente 3). Des explications alternatives de l’effet observé sont discutées, basées sur les interactions entre les processus du remplissage de la luminosité et du mouvement

    Human Heading Perception Based on Form and Motion Combination

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    International audienceThis paper presents a study on human perception of the heading on the base of motion and form visual cues integration. The authors examine how human age influences this process. Because the visual stimuli are in general uncertain, or in some cases even conflicting, the process of combination is estimated on the base on the well known Normalized Conjunctive Consensus fusion rule, as well as on the base of the more efficient Dezert-Smarandache Theory (DSmT) of plausible and paradoxical reasoning, and more precisely on the probabilistic Proportional Conflict Redistribution rule no.5 defined within it. The main goal is focused on how these fusion rules succeed to model consistent and adequate predictions about both individuals' behavior, and age-contingent groups of individuals

    Elimination of the color discrimination impairment along the blue–yellow axis in patients with hypothyroidism after treatment with levothyroxine as assessed by the Farnsworth–Munsell 100 hue test.

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    Our previous study has shown that individuals with untreated hypothyroidism display significantly higher partial error scores (√PES) along the blue–yellow axis compared to the red–green axis than normal individuals using the Farnsworth–Munsell 100 hue test [J. Opt. Soc. Am. A 37, A18 (2020)]. We wished to determine how color discrimination may change when hypothyroidism has been treated to the point of euthyroidism. Color discrimination was reassessed for 17 female individuals who had undergone treatment for hypothyroidism, and the results were compared with 22 female individuals without thyroid dysfunction. No statistically significant difference was found in the total error score (√TES) for the first and second measurements for both groups (>0.45). The √PES for the hypothyroid group improved significantly in the previously impaired color regions after the treatment. Color discrimination defects found in untreated hypothyroidism can be negated with treatment of the condition over an appropriate time period

    How the External Visual Noise Affects Motion Direction Discrimination in Autism Spectrum Disorder

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    Along with social, cognitive, and behavior deficiencies, peculiarities in sensory processing, including an atypical global motion processing, have been reported in Autism Spectrum Disorder (ASD). The question about the enhanced motion pooling in ASD is still debatable. The aim of the present study was to compare global motion integration in ASD using a low-density display and the equivalent noise (EN) approach. Fifty-seven children and adolescents with ASD or with typical development (TD) had to determine the average direction of movement of 30 Laplacian-of-Gaussian micro-patterns. They moved in directions determined by a normal distribution with a standard deviation of 2°, 5°, 10°, 15°, 25°, and 35°, corresponding to the added external noise. The data obtained showed that the ASD group has much larger individual differences in motion direction thresholds on external noise effect than the TD group. Applying the equivalent noise paradigm, we found that the global motion direction discrimination thresholds were more elevated in ASD than in controls at all noise levels. These results suggest that ASD individuals have a poor ability to integrate the local motion information in low-density displays

    hypothyroidism

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    Supplementary materials for Visual, Spatial, and Temporal Integration in Patients with Hypothyroidis

    Design and Analysis of a Relational Database for Behavioral Experiments Data Processing

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    In this paper, the results of a comparative analysis between different approaches to experimental data storage and processing are presented. Several studies related to the problem and some methods for solving it have been discussed. Different types of databases, ways of using them and the areas of their application are analyzed. For the purposes of the study, a relational database for storing and analyzing a specific data from behavioral experiments was designed. The methodology and conditions for conducting the experiments are described. Three different indicators were analyzed, respectively: memory required to store the data, time to load the data from an external file into computer memory and iteration time across all records through one cycle. The obtained results show that for storing a large number of records (in the order of tens of millions of rows), either dynamic arrays (stored on external media in binary file format), or an approach based on a local or remote database management system can be used. Regarding the data loading time, the fastest approach was the one that uses dynamic arrays. It outperforms significantly the approaches based on a local or remote database. The obtained results show that the dynamic arrays and the local data sets approaches iterated much faster across all data records than the remote database approach. The paper concludes with proposal for further developments towards using of web services

    An Analysis of a Web Service based Approach for Experimental Data Sharing

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    This paper presents the results obtained from a comparative analysis of two methods for experimental data sharing. Several works related to the topic and some approaches for processing data have been discussed. Different technolgoies related to the web services, ways of using them and the areas of their application are analyzed. For the purposes of the study, a web service for retrieving specific data from a behavioral experiments database was developed.The methodology and conditions for conducting the experiments are described. Two different indicators are analyzed, respectively: time to retrieve the data from a database and iteration time across all records through one loop. The results show that when retrieving thousands of records both web service based approach and an approach based on a remote database server can be used. However, when retrieving millions of records, the fastest approach was the one that uses remote database server. The obtainedresultsshow that the dynamic arrays (containing strings) iterated much faster across all data records than the dataset approach.</span

    Design and Analysis of a Relational Database for Behavioral Experiments Data Processing

    No full text
    In this paper, the results of a comparative analysis between different approaches to experimental data storage and processing are presented. Several studies related to the problem and some methods for solving it have been discussed. Different types of databases, ways of using them and the areas of their application are analyzed. For the purposes of the study, a relational database for storing and analyzing a specific data from behavioral experiments was designed. The methodology and conditions for conducting the experiments are described. Three different indicators were analyzed, respectively: memory required to store the data, time to load the data from an external file into computer memory and iteration time across all records through one cycle. The obtained results show that for storing a large number of records (in the order of tens of millions of rows), either dynamic arrays (stored on external media in binary file format), or an approach based on a local or remote database management system can be used. Regarding the data loading time, the fastest approach was the one that uses dynamic arrays. It outperforms significantly the approaches based on a local or remote database. The obtained results show that the dynamic arrays and the local data sets approaches iterated much faster across all data records than the remote database approach. The paper concludes with proposal for further developments towards using of web services
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