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Sample records for aging visual system

  1. Age-related gene expression change of GABAergic system in visual cortex of rhesus macaque.

    PubMed

    Liao, Chenghong; Han, Qian; Ma, Yuanye; Su, Bing

    2016-09-30

    Degradation of visual function is a common phenomenon during aging and likely mediated by change in the impaired central visual pathway. Treatment with GABA or its agonist could recover the ability of visual neurons in the primary visual cortex of senescent macaques. However, little is known about how GABAergic system change is related to the aged degradation of visual function in nonhuman primate. With the use of quantitative PCR method, we measured the expression change of 24 GABA related genes in the primary visual cortex (Brodmann's 17) of different age groups. In this study, both of mRNA and protein of glutamic acid decarboxylase (GAD65) were measured by real-time RT-PCR and Western blot, respectively. Results revealed that the level of GAD65 message was not significantly altered, but the proteins were significantly decreased in the aged monkey. As GAD65 plays an important role in GABA synthesis, the down-regulation of GAD65 protein was likely the key factor leading to the observed GABA reduction in the primary visual cortex of the aged macaques. In addition, 7 of 14 GABA receptor genes were up-regulated and one GABA receptor gene was significantly reduced during aging process even after Banjamini correction for multiple comparisons (P<0.05). These results suggested that the dysregulation of GAD65 protein might contribute to some age-related neural visual dysfunctions and most of GABA receptor genes induce a clear indication of compensatory effect for the reduced GABA release in the healthy aged monkey cortex. PMID:27196061

  2. Aging and Visual Impairment.

    ERIC Educational Resources Information Center

    Morse, A. R.; And Others

    1987-01-01

    Eye diseases of the aged include diabetic retinopathy, senile cataracts, senile macular degeneration, and glaucoma. Environmental modifications such as better levels of illumination and reduction of glare can enhance an individual's ability to function. Programs to screen and treat visual problems in elderly persons are called for. (Author/JDD)

  3. Visual Alert System

    NASA Technical Reports Server (NTRS)

    1985-01-01

    A visual alert system resulted from circuitry developed by Applied Cybernetics Systems for Langley as part of a space related telemetry system. James Campman, Applied Cybernetics president, left the company and founded Grace Industries, Inc. to manufacture security devices based on the Langley technology. His visual alert system combines visual and audible alerts for hearing impaired people. The company also manufactures an arson detection device called the electronic nose, and is currently researching additional applications of the NASA technology.

  4. The ups and downs of global motion perception: a paradoxical advantage for smaller stimuli in the aging visual system

    PubMed Central

    Hutchinson, Claire V.; Ledgeway, Tim; Allen, Harriet A.

    2014-01-01

    Recent evidence suggests that normal aging is typically accompanied by impairment in the ability to perceive the global (overall) motion of visual objects in the world. The purpose of this study was to examine the interplay between age-related changes in the ability to perceive translational global motion (up vs. down) and important factors such as the spatial extent (size) over which movement occurs and how cluttered the moving elements are (density). We used random dot kinematograms (RDKs) and measured motion coherence thresholds (% signal elements required to reliably discriminate global direction) for young and older adults. We did so as a function of the number and density of local signal elements, and the aperture area in which they were displayed. We found that older adults’ performance was relatively unaffected by changes in aperture size, the number and density of local elements in the display. In young adults, performance was also insensitive to element number and density but was modulated markedly by display size, such that motion coherence thresholds decreased as aperture area increased (participants required fewer local elements to move coherently to determine the overall image direction). With the smallest apertures tested, young participants’ motion coherence thresholds were considerably higher (~1.5 times worse) than those of their older counterparts. Therefore, when RDK size is relatively small, older participants were actually better than young participants at processing global motion. These findings suggest that the normal (disease-free) aging process does not lead to a general decline in perceptual ability and in some cases may be visually advantageous. The results have important implications for the understanding of the consequences of aging on visual function and a number of potential explanations are explored. These include age-related changes in spatial summation, reduced cortical inhibition, neural blur and attentional resource

  5. Visual cortex in aging and Alzheimer's disease: changes in visual field maps and population receptive fields

    PubMed Central

    Brewer, Alyssa A.; Barton, Brian

    2012-01-01

    Although several studies have suggested that cortical alterations underlie such age-related visual deficits as decreased acuity, little is known about what changes actually occur in visual cortex during healthy aging. Two recent studies showed changes in primary visual cortex (V1) during normal aging; however, no studies have characterized the effects of aging on visual cortex beyond V1, important measurements both for understanding the aging process and for comparison to changes in age-related diseases. Similarly, there is almost no information about changes in visual cortex in Alzheimer's disease (AD), the most common form of dementia. Because visual deficits are often reported as one of the first symptoms of AD, measurements of such changes in the visual cortex of AD patients might improve our understanding of how the visual system is affected by neurodegeneration as well as aid early detection, accurate diagnosis and timely treatment of AD. Here we use fMRI to first compare the visual field map (VFM) organization and population receptive fields (pRFs) between young adults and healthy aging subjects for occipital VFMs V1, V2, V3, and hV4. Healthy aging subjects do not show major VFM organizational deficits, but do have reduced surface area and increased pRF sizes in the foveal representations of V1, V2, and hV4 relative to healthy young control subjects. These measurements are consistent with behavioral deficits seen in healthy aging. We then demonstrate the feasibility and first characterization of these measurements in two patients with mild AD, which reveal potential changes in visual cortex as part of the pathophysiology of AD. Our data aid in our understanding of the changes in the visual processing pathways in normal aging and provide the foundation for future research into earlier and more definitive detection of AD. PMID:24570669

  6. The Drosophila visual system

    PubMed Central

    Zhu, Yan

    2013-01-01

    A compact genome and a tiny brain make Drosophila the prime model to understand the neural substrate of behavior. The neurogenetic efforts to reveal neural circuits underlying Drosophila vision started about half a century ago, and now the field is booming with sophisticated genetic tools, rich behavioral assays, and importantly, a greater number of scientists joining from different backgrounds. This review will briefly cover the structural anatomy of the Drosophila visual system, the animal’s visual behaviors, the genes involved in assembling these circuits, the new and powerful techniques, and the challenges ahead for ultimately identifying the general principles of biological computation in the brain.   A typical brain utilizes a great many compact neural circuits to collect and process information from the internal biological and external environmental worlds and generates motor commands for observable behaviors. The fruit fly Drosophila melanogaster, despite of its miniature body and tiny brain, can survive in almost any corner of the world.1 It can find food, court mate, fight rival conspecific, avoid predators, and amazingly fly without crashing into trees. Drosophila vision and its underlying neuronal machinery has been a key research model for at least half century for neurogeneticists.2 Given the efforts invested on the visual system, this animal model is likely to offer the first full understanding of how visual information is computed by a multi-cellular organism. Furthermore, research in Drosophila has revealed many genes that play crucial roles in the formation of functional brains across species. The architectural similarities between the visual systems of Drosophila and vertebrate at the molecular, cellular, and network levels suggest new principles discovered at the circuit level on the relationship between neurons and behavior in Drosophila shall also contribute greatly to our understanding of the general principles for how bigger brains work.3

  7. Solar System Visualizations

    NASA Technical Reports Server (NTRS)

    Brown, Alison M.

    2005-01-01

    Solar System Visualization products enable scientists to compare models and measurements in new ways that enhance the scientific discovery process, enhance the information content and understanding of the science results for both science colleagues and the public, and create.visually appealing and intellectually stimulating visualization products. Missions supported include MER, MRO, and Cassini. Image products produced include pan and zoom animations of large mosaics to reveal the details of surface features and topography, animations into registered multi-resolution mosaics to provide context for microscopic images, 3D anaglyphs from left and right stereo pairs, and screen captures from video footage. Specific products include a three-part context animation of the Cassini Enceladus encounter highlighting images from 350 to 4 meter per pixel resolution; Mars Reconnaissance Orbiter screen captures illustrating various instruments during assembly and testing at the Payload Hazardous Servicing Facility at Kennedy Space Center; and an animation of Mars Exploration Rover Opportunity's 'Rub al Khali' panorama where the rover was stuck in the deep fine sand for more than a month. This task creates new visualization products that enable new science results and enhance the public's understanding of the Solar System and NASA's missions of exploration.

  8. GVS - GENERAL VISUALIZATION SYSTEM

    NASA Technical Reports Server (NTRS)

    Keith, S. R.

    1994-01-01

    The primary purpose of GVS (General Visualization System) is to support scientific visualization of data output by the panel method PMARC_12 (inventory number ARC-13362) on the Silicon Graphics Iris computer. GVS allows the user to view PMARC geometries and wakes as wire frames or as light shaded objects. Additionally, geometries can be color shaded according to phenomena such as pressure coefficient or velocity. Screen objects can be interactively translated and/or rotated to permit easy viewing. Keyframe animation is also available for studying unsteady cases. The purpose of scientific visualization is to allow the investigator to gain insight into the phenomena they are examining, therefore GVS emphasizes analysis, not artistic quality. GVS uses existing IRIX 4.0 image processing tools to allow for conversion of SGI RGB files to other formats. GVS is a self-contained program which contains all the necessary interfaces to control interaction with PMARC data. This includes 1) the GVS Tool Box, which supports color histogram analysis, lighting control, rendering control, animation, and positioning, 2) GVS on-line help, which allows the user to access control elements and get information about each control simultaneously, and 3) a limited set of basic GVS data conversion filters, which allows for the display of data requiring simpler data formats. Specialized controls for handling PMARC data include animation and wakes, and visualization of off-body scan volumes. GVS is written in C-language for use on SGI Iris series computers running IRIX. It requires 28Mb of RAM for execution. Two separate hardcopy documents are available for GVS. The basic document price for ARC-13361 includes only the GVS User's Manual, which outlines major features of the program and provides a tutorial on using GVS with PMARC_12 data. Programmers interested in modifying GVS for use with data in formats other than PMARC_12 format may purchase a copy of the draft GVS 3.1 Software Maintenance

  9. Complex Digital Visual Systems

    ERIC Educational Resources Information Center

    Sweeny, Robert W.

    2013-01-01

    This article identifies possibilities for data visualization as art educational research practice. The author presents an analysis of the relationship between works of art and digital visual culture, employing aspects of network analysis drawn from the work of Barabási, Newman, and Watts (2006) and Castells (1994). Describing complex network…

  10. Crawling-Onset Age Predicts Visual Cliff Avoidance in Infants.

    ERIC Educational Resources Information Center

    Richards, John E.; Rader, Nancy

    1981-01-01

    Two experiments tested the effects of crawling-onset age, amount of crawling experience, and testing age on avoidance of the deep side of a visual cliff apparatus by human infants. Crawling-onset age disciminated between infants because crawling during the tactile phase interferes with later visual control of locomotion. (Author/RD)

  11. How to Select Visuals: The Information-Visualization System.

    ERIC Educational Resources Information Center

    Langdon, Danny G.

    1986-01-01

    Presents an overview and an example of use of the Information-Visualization System, an approach to visual selection enabling educators to match desired learning outcomes with the best visuals to carry the message. Decision tables and resource book containing visual options, information types, and suggested methods of enhancing visuals are…

  12. Helicopter Visual Aid System

    NASA Technical Reports Server (NTRS)

    Baisley, R. L.

    1973-01-01

    The results of an evaluation of police helicopter effectiveness revealed a need for improved visual capability. A JPL program developed a method that would enhance visual observation capability for both day and night usage and demonstrated the feasibility of the adopted approach. This approach made use of remote pointable optics, a display screen, a slaved covert searchlight, and a coupled camera. The approach was proved feasible through field testing and by judgement against evaluation criteria.

  13. Functional Visual Acuity in Age-Related Macular Degeneration

    PubMed Central

    Tomita, Yohei; Nagai, Norihiro; Suzuki, Misa; Shinoda, Hajime; Uchida, Atsuro; Mochimaru, Hiroshi; Izumi-Nagai, Kanako; Sasaki, Mariko; Tsubota, Kazuo; Ozawa, Yoko

    2016-01-01

    ABSTRACT Purpose We evaluated whether a functional visual acuity (FVA) system can detect subtle changes in central visual acuity that reflect pathological findings associated with age-related macular degeneration (AMD). Methods Twenty-eight patients with unilateral AMD and logMAR monocular best corrected VA better than 0 in both eyes, as measured by conventional chart examination, were analyzed between November 2012 and April 2013. After measuring conventional VA, FVA, and contrast VA with best correction, routine eye examinations including spectral domain–optical coherence tomography were performed. Standard Schirmer test was performed, and corneal and lens densities were measured. Results The FVA score (p < 0.001) and visual maintenance ratio (p < 0.001) measured by the FVA system, contrast VA (p < 0. 01), and conventional VA (p < 0.01) were significantly worse in the AMD-affected eyes than in the fellow eyes. No significant differences were observed in the anterior segment conditions. Forward stepwise regression analysis demonstrated that the length of interdigitation zone disruption, as visualized by optical coherence tomography imaging, correlated with the FVA score (p < 0.01) but not with any other parameters investigated. Conclusions The FVA system detects subtle changes in best corrected VA in AMD-affected eyes and reflects interdigitation zone disruption, an anatomical change in the retina recorded by optical coherence tomography. Further studies are required to understand the value of the FVA system in detecting subtle changes in AMD. PMID:26583795

  14. Aging Effect on Visual and Spatial Components of Working Memory

    ERIC Educational Resources Information Center

    Beigneux, Katia; Plaie, Thierry; Isingrini, Michel

    2007-01-01

    The aim of this study was to evaluate the effect of aging on the storage of visual and spatial working memory according to Logie's model of working memory (1995). In a first experiment young, elderly, and very old subjects carried out two tasks usually used to measure visual span (Visual Patterns Test) and spatial span (Corsi Block Tapping test).…

  15. Effects of aging on audio-visual speech integration.

    PubMed

    Huyse, Aurélie; Leybaert, Jacqueline; Berthommier, Frédéric

    2014-10-01

    This study investigated the impact of aging on audio-visual speech integration. A syllable identification task was presented in auditory-only, visual-only, and audio-visual congruent and incongruent conditions. Visual cues were either degraded or unmodified. Stimuli were embedded in stationary noise alternating with modulated noise. Fifteen young adults and 15 older adults participated in this study. Results showed that older adults had preserved lipreading abilities when the visual input was clear but not when it was degraded. The impact of aging on audio-visual integration also depended on the quality of the visual cues. In the visual clear condition, the audio-visual gain was similar in both groups and analyses in the framework of the fuzzy-logical model of perception confirmed that older adults did not differ from younger adults in their audio-visual integration abilities. In the visual reduction condition, the audio-visual gain was reduced in the older group, but only when the noise was stationary, suggesting that older participants could compensate for the loss of lipreading abilities by using the auditory information available in the valleys of the noise. The fuzzy-logical model of perception confirmed the significant impact of aging on audio-visual integration by showing an increased weight of audition in the older group. PMID:25324091

  16. Science information systems: Visualization

    NASA Technical Reports Server (NTRS)

    Wall, Ray J.

    1991-01-01

    Future programs in earth science, planetary science, and astrophysics will involve complex instruments that produce data at unprecedented rates and volumes. Current methods for data display, exploration, and discovery are inadequate. Visualization technology offers a means for the user to comprehend, explore, and examine complex data sets. The goal of this program is to increase the effectiveness and efficiency of scientists in extracting scientific information from large volumes of instrument data.

  17. Do gender differences in audio-visual benefit and visual influence in audio-visual speech perception emerge with age?

    PubMed Central

    Alm, Magnus; Behne, Dawn

    2015-01-01

    Gender and age have been found to affect adults’ audio-visual (AV) speech perception. However, research on adult aging focuses on adults over 60 years, who have an increasing likelihood for cognitive and sensory decline, which may confound positive effects of age-related AV-experience and its interaction with gender. Observed age and gender differences in AV speech perception may also depend on measurement sensitivity and AV task difficulty. Consequently both AV benefit and visual influence were used to measure visual contribution for gender-balanced groups of young (20–30 years) and middle-aged adults (50–60 years) with task difficulty varied using AV syllables from different talkers in alternative auditory backgrounds. Females had better speech-reading performance than males. Whereas no gender differences in AV benefit or visual influence were observed for young adults, visually influenced responses were significantly greater for middle-aged females than middle-aged males. That speech-reading performance did not influence AV benefit may be explained by visual speech extraction and AV integration constituting independent abilities. Contrastingly, the gender difference in visually influenced responses in middle adulthood may reflect an experience-related shift in females’ general AV perceptual strategy. Although young females’ speech-reading proficiency may not readily contribute to greater visual influence, between young and middle-adulthood recurrent confirmation of the contribution of visual cues induced by speech-reading proficiency may gradually shift females AV perceptual strategy toward more visually dominated responses. PMID:26236274

  18. Auditory and visual memory losses in aging populations.

    PubMed

    Boyle, E; Aparicio, A M; Kaye, J; Acker, M

    1975-06-01

    Seventy-four men and women (age range, 44-77 years) were tested for short-term auditory and visual memory as part of a larger series of memory and cognitive function tests. All test scores for visual memory, including facial photograph recognition when a sequence requirement was adhered to, showed a significant decline (p smaller than .05) in a comparison of subjects aged 44-54 and subjects aged 55-64. This decline was not observed with the two tests of auditory memory. Thus the data indicate that short-term visual memory may be more susceptible to aging than is auditory memory. PMID:1127202

  19. Visualizing Parallel Computer System Performance

    NASA Technical Reports Server (NTRS)

    Malony, Allen D.; Reed, Daniel A.

    1988-01-01

    Parallel computer systems are among the most complex of man's creations, making satisfactory performance characterization difficult. Despite this complexity, there are strong, indeed, almost irresistible, incentives to quantify parallel system performance using a single metric. The fallacy lies in succumbing to such temptations. A complete performance characterization requires not only an analysis of the system's constituent levels, it also requires both static and dynamic characterizations. Static or average behavior analysis may mask transients that dramatically alter system performance. Although the human visual system is remarkedly adept at interpreting and identifying anomalies in false color data, the importance of dynamic, visual scientific data presentation has only recently been recognized Large, complex parallel system pose equally vexing performance interpretation problems. Data from hardware and software performance monitors must be presented in ways that emphasize important events while eluding irrelevant details. Design approaches and tools for performance visualization are the subject of this paper.

  20. Differential Age Effects on Spatial and Visual Working Memory

    ERIC Educational Resources Information Center

    Oosterman, Joukje M.; Morel, Sascha; Meijer, Lisette; Buvens, Cleo; Kessels, Roy P. C.; Postma, Albert

    2011-01-01

    The present study was intended to compare age effects on visual and spatial working memory by using two versions of the same task that differed only in presentation mode. The working memory task contained both a simultaneous and a sequential presentation mode condition, reflecting, respectively, visual and spatial working memory processes. Young…

  1. Component-Based Visualization System

    NASA Technical Reports Server (NTRS)

    Delgado, Francisco

    2005-01-01

    A software system has been developed that gives engineers and operations personnel with no "formal" programming expertise, but who are familiar with the Microsoft Windows operating system, the ability to create visualization displays to monitor the health and performance of aircraft/spacecraft. This software system is currently supporting the X38 V201 spacecraft component/system testing and is intended to give users the ability to create, test, deploy, and certify their subsystem displays in a fraction of the time that it would take to do so using previous software and programming methods. Within the visualization system there are three major components: the developer, the deployer, and the widget set. The developer is a blank canvas with widget menu items that give users the ability to easily create displays. The deployer is an application that allows for the deployment of the displays created using the developer application. The deployer has additional functionality that the developer does not have, such as printing of displays, screen captures to files, windowing of displays, and also serves as the interface into the documentation archive and help system. The third major component is the widget set. The widgets are the visual representation of the items that will make up the display (i.e., meters, dials, buttons, numerical indicators, string indicators, and the like). This software was developed using Visual C++ and uses COTS (commercial off-the-shelf) software where possible.

  2. SUBSURFACE VISUAL ALARM SYSTEM ANALYSIS

    SciTech Connect

    D.W. Markman

    2001-08-06

    The ''Subsurface Fire Hazard Analysis'' (CRWMS M&O 1998, page 61), and the document, ''Title III Evaluation Report for the Surface and Subsurface Communication System'', (CRWMS M&O 1999a, pages 21 and 23), both indicate the installed communication system is adequate to support Exploratory Studies Facility (ESF) activities with the exception of the mine phone system for emergency notification purposes. They recommend the installation of a visual alarm system to supplement the page/party phone system The purpose of this analysis is to identify data communication highway design approaches, and provide justification for the selected or recommended alternatives for the data communication of the subsurface visual alarm system. This analysis is being prepared to document a basis for the design selection of the data communication method. This analysis will briefly describe existing data or voice communication or monitoring systems within the ESF, and look at how these may be revised or adapted to support the needed data highway of the subsurface visual alarm. system. The existing PLC communication system installed in subsurface is providing data communication for alcove No.5 ventilation fans, south portal ventilation fans, bulkhead doors and generator monitoring system. It is given that the data communication of the subsurface visual alarm system will be a digital based system. It is also given that it is most feasible to take advantage of existing systems and equipment and not consider an entirely new data communication system design and installation. The scope and primary objectives of this analysis are to: (1) Briefly review and describe existing available data communication highways or systems within the ESF. (2) Examine technical characteristics of an existing system to disqualify a design alternative is paramount in minimizing the number of and depth of a system review. (3) Apply general engineering design practices or criteria such as relative cost, and degree of

  3. Entrance Age and Visual Motor Integration.

    ERIC Educational Resources Information Center

    Foote, Elizabeth

    This study examines the degree of correlation between the age of a child on entering kindergarten and the child's academic achievement. A review of literature provides evidence that premature learning may actually create a block to later learning. One study reported that many chronologically young children who had a higher than average I.Q. failed…

  4. Age-Related Changes in Visual Pseudoneglect

    ERIC Educational Resources Information Center

    Schmitz, Remy; Peigneux, Philippe

    2011-01-01

    Pseudoneglect is a slight but consistent leftward attentional bias commonly observed in healthy young populations, purportedly explained by right hemispheric dominance. It has been suggested that normal aging might be associated with a decline of the right hemisphere. According to this hypothesis, a few studies have shown that elderly tend to…

  5. Space shuttle visual simulation system design study

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A recommendation and a specification for the visual simulation system design for the space shuttle mission simulator are presented. A recommended visual system is described which most nearly meets the visual design requirements. The cost analysis of the recommended system covering design, development, manufacturing, and installation is reported. Four alternate systems are analyzed.

  6. [Visualization of the age-related changes in expressions of DNA methyltransferases in mouse oocytes using two-photon imaging system].

    PubMed

    Tian, Ning; Zhang, Lu; Zheng, Jing-Hao; Li, Ying; Ma, Wan-Yun

    2012-12-01

    Quantum dot (QD) is widely used as fluorescent labeling dye for its strong anti-fluorescence quenching, high quantum yield, wide absorption spectra, and narrow emission spectra. In the present paper, QD 585-labeled DNA methyltransferases (Dnmts) and Hoechst 33342-labeled chromosomes were imaged simultaneously using two-photon imaging system. The authors' results showed that aging mouse oocytes may be not suitable for in-vitro maturation: both the localizations and expression levels of Dnmts in in-vitro matured oocytes of aging mice were changed, and these changes may be related to the abnormal DNA methylation modification. PMID:23427529

  7. [The effect of age on inhibition of visual fixation of the rotatory-induced nystagmus reaction].

    PubMed

    Aust, G

    1993-01-01

    The interactive functions between sensory systems show changes that depend on the development of the growing body. Important conditions for the development of the visual suppression of vestibular evoked nystagmus reactions are the maturation of the visual system, the presence of a functioning vestibular system and close connections between both systems. Response to vestibular, visual and combined vestibular and visual stimulation does not only change during early childhood. We have also learnt from studies of adults of different ages that there are characteristic changes in nystagmus reactions to vestibular stimulation, in optokinetic reactions and in vestibular-spinal functions during the whole period of life. 272 randomly selected neuro-otologic routine patients aged between one year and four months and eighty-eight years and ten months were included in the study to analyse age-related changes of visual suppression during rotatory stimulation. The rotatory stimulation consisted of an sinusoidal stimulus pattern with amplitudes of +/- 180 degrees and a period duration of 20s. The vestibular stimulation was performed in total darkness and with a visual target which was attached to the chair in front of the patient's eyes. The results of this study demonstrate that the amplitudes of nystagmus reactions, evoked by sinusoidal harmonic acceleration, can be quantitatively suppressed by visual fixation. The degree of suppression depends on age. The fixation indices provide the ability to measure the degree of this suppression in percent. The trend to better fixation suppression increases up to the end of the age of forty. The ability to suppress vestibular nystagmus decreases, however, after reaching the fortieth year of life. The analysis of smooth pursuit shows after the sixtieth year of life a continuous rise in the number of saccades with increasing age. These changes are caused by aging processes in cerebral tissues which lead to functional changes e.g. in the

  8. Relating Standardized Visual Perception Measures to Simulator Visual System Performance

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary K.; Sweet, Barbara T.

    2013-01-01

    Human vision is quantified through the use of standardized clinical vision measurements. These measurements typically include visual acuity (near and far), contrast sensitivity, color vision, stereopsis (a.k.a. stereo acuity), and visual field periphery. Simulator visual system performance is specified in terms such as brightness, contrast, color depth, color gamut, gamma, resolution, and field-of-view. How do these simulator performance characteristics relate to the perceptual experience of the pilot in the simulator? In this paper, visual acuity and contrast sensitivity will be related to simulator visual system resolution, contrast, and dynamic range; similarly, color vision will be related to color depth/color gamut. Finally, we will consider how some characteristics of human vision not typically included in current clinical assessments could be used to better inform simulator requirements (e.g., relating dynamic characteristics of human vision to update rate and other temporal display characteristics).

  9. The Prevalence of Age-Related Eye Diseases and Visual Impairment in Aging: Current Estimates

    PubMed Central

    Klein, Ronald; Klein, Barbara E. K.

    2013-01-01

    Purpose. To examine prevalence of five age-related eye conditions (age-related cataract, AMD, open-angle glaucoma, diabetic retinopathy [DR], and visual impairment) in the United States. Methods. Review of published scientific articles and unpublished research findings. Results. Cataract, AMD, open-angle glaucoma, DR, and visual impairment prevalences are high in four different studies of these conditions, especially in people over 75 years of age. There are disparities among racial/ethnic groups with higher age-specific prevalence of DR, open-angle glaucoma, and visual impairment in Hispanics and blacks compared with whites, higher prevalence of age-related cataract in whites compared with blacks, and higher prevalence of late AMD in whites compared with Hispanics and blacks. The estimates are based on old data and do not reflect recent changes in the distribution of age and race/ethnicity in the United States population. There are no epidemiologic estimates of prevalence for many visually-impairing conditions. Conclusions. Ongoing prevalence surveys designed to provide reliable estimates of visual impairment, AMD, age-related cataract, open-angle glaucoma, and DR are needed. It is important to collect objective data on these and other conditions that affect vision and quality of life in order to plan for health care needs and identify areas for further research. PMID:24335069

  10. Space shuttle visual simulation system design study

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The current and near-future state-of-the-art in visual simulation equipment technology is related to the requirements of the space shuttle visual system. Image source, image sensing, and displays are analyzed on a subsystem basis, and the principal conclusions are used in the formulation of a recommended baseline visual system. Perceptibility and visibility are also analyzed.

  11. Aging affects postural tracking of complex visual motion cues.

    PubMed

    Sotirakis, H; Kyvelidou, A; Mademli, L; Stergiou, N; Hatzitaki, V

    2016-09-01

    Postural tracking of visual motion cues improves perception-action coupling in aging, yet the nature of the visual cues to be tracked is critical for the efficacy of such a paradigm. We investigated how well healthy older (72.45 ± 4.72 years) and young (22.98 ± 2.9 years) adults can follow with their gaze and posture horizontally moving visual target cues of different degree of complexity. Participants tracked continuously for 120 s the motion of a visual target (dot) that oscillated in three different patterns: a simple periodic (simulated by a sine), a more complex (simulated by the Lorenz attractor that is deterministic displaying mathematical chaos) and an ultra-complex random (simulated by surrogating the Lorenz attractor) pattern. The degree of coupling between performance (posture and gaze) and the target motion was quantified in the spectral coherence, gain, phase and cross-approximate entropy (cross-ApEn) between signals. Sway-target coherence decreased as a function of target complexity and was lower for the older compared to the young participants when tracking the chaotic target. On the other hand, gaze-target coherence was not affected by either target complexity or age. Yet, a lower cross-ApEn value when tracking the chaotic stimulus motion revealed a more synchronous gaze-target relationship for both age groups. Results suggest limitations in online visuo-motor processing of complex motion cues and a less efficient exploitation of the body sway dynamics with age. Complex visual motion cues may provide a suitable training stimulus to improve visuo-motor integration and restore sway variability in older adults. PMID:27126061

  12. Presentation Technology in the Age of Electronic Eloquence: From Visual Aid to Visual Rhetoric

    ERIC Educational Resources Information Center

    Cyphert, Dale

    2007-01-01

    Attention to presentation technology in the public speaking classroom has grown along with its contemporary use, but instruction generally positions the topic as a subset of visual aids. As contemporary public discourse enters an age of electronic eloquence, instructional focus on verbal communication might limit students' capacity to effectively…

  13. [Visual fixation features after treatment of exudative age macular degeneration].

    PubMed

    Surguch, V K; Surnina, Z V; Sizova, M V

    2011-01-01

    Changes of visual fixation in patients with choroidal neovascularitation (CNV) associated with age macular degeneration (AMD) after bevacizumab are studied. 45 patients (45 eyes) with active CNV treated with intravitreal bevacizumab were enrolled into the study. Visual fixation was studied before and 3-6 months after treatment using original method that included fundus foto and fluorescein angiography. Fixation relative to fovea and lesion was evaluated. Foveal fixation beyond lesion was found in 9%, foveal fixation within lesion--in 47%, extrafoveal fixation beyond lesion--in 18%, extrafoveal fixation within lesion--in 26% of patients. Changes of fixation localization after treatment was found in 24% patients. Examination of visual fixation may be useful for prognosis of anti-VEGF treatment efficacy in patients with CNV. PMID:21721271

  14. Visually-induced reorientation illusions as a function of age.

    PubMed

    Howard, I P; Jenkin, H L; Hu, G

    2000-09-01

    We reported previously that supine subjects inside a furnished room who are tilted 90 degrees may experience themselves and the room as upright to gravity. We call this the levitation illusion because it creates sensations similar to those experienced in weightlessness. It is an example of a larger class of novel static reorientation illusions that we have explored. Stationary subjects inside a furnished room rotating about a horizontal axis experience complete self rotation about the roll or pitch axis. We call this a dynamic reorientation illusion. We have determined the incidence of static and dynamic reorientation illusions in subjects ranging in age from 9 to 78 yr. Some 90% of subjects of all ages experienced the dynamic reorientation illusion but the percentage of subjects experiencing static reorientation illusions increased with age. We propose that the dynamic illusion depends on a primitive mechanism of visual-vestibular interaction but that static reorientation illusions depend on learned visual cues to the vertical arising from the perceived tops and bottoms of familiar objects and spatial relationships between objects. Older people become more dependent on visual polarity to compensate for loss in vestibular sensitivity. Of 9 astronauts, 4 experienced the levitation illusion. The relationship between susceptibility to reorientation illusions on Earth and in space has still to be determined. We propose that the Space Station will be less disorienting if pictures of familiar objects line the walls. PMID:10993316

  15. Distinct Visual Evoked Potential Morphological Patterns for Apparent Motion Processing in School-Aged Children

    PubMed Central

    Campbell, Julia; Sharma, Anu

    2016-01-01

    Measures of visual cortical development in children demonstrate high variability and inconsistency throughout the literature. This is partly due to the specificity of the visual system in processing certain features. It may then be advantageous to activate multiple cortical pathways in order to observe maturation of coinciding networks. Visual stimuli eliciting the percept of apparent motion and shape change is designed to simultaneously activate both dorsal and ventral visual streams. However, research has shown that such stimuli also elicit variable visual evoked potential (VEP) morphology in children. The aim of this study was to describe developmental changes in VEPs, including morphological patterns, and underlying visual cortical generators, elicited by apparent motion and shape change in school-aged children. Forty-one typically developing children underwent high-density EEG recordings in response to a continuously morphing, radially modulated, circle-star grating. VEPs were then compared across the age groups of 5–7, 8–10, and 11–15 years according to latency and amplitude. Current density reconstructions (CDR) were performed on VEP data in order to observe activated cortical regions. It was found that two distinct VEP morphological patterns occurred in each age group. However, there were no major developmental differences between the age groups according to each pattern. CDR further demonstrated consistent visual generators across age and pattern. These results describe two novel VEP morphological patterns in typically developing children, but with similar underlying cortical sources. The importance of these morphological patterns is discussed in terms of future studies and the investigation of a relationship to visual cognitive performance. PMID:27445738

  16. Distinct Visual Evoked Potential Morphological Patterns for Apparent Motion Processing in School-Aged Children.

    PubMed

    Campbell, Julia; Sharma, Anu

    2016-01-01

    Measures of visual cortical development in children demonstrate high variability and inconsistency throughout the literature. This is partly due to the specificity of the visual system in processing certain features. It may then be advantageous to activate multiple cortical pathways in order to observe maturation of coinciding networks. Visual stimuli eliciting the percept of apparent motion and shape change is designed to simultaneously activate both dorsal and ventral visual streams. However, research has shown that such stimuli also elicit variable visual evoked potential (VEP) morphology in children. The aim of this study was to describe developmental changes in VEPs, including morphological patterns, and underlying visual cortical generators, elicited by apparent motion and shape change in school-aged children. Forty-one typically developing children underwent high-density EEG recordings in response to a continuously morphing, radially modulated, circle-star grating. VEPs were then compared across the age groups of 5-7, 8-10, and 11-15 years according to latency and amplitude. Current density reconstructions (CDR) were performed on VEP data in order to observe activated cortical regions. It was found that two distinct VEP morphological patterns occurred in each age group. However, there were no major developmental differences between the age groups according to each pattern. CDR further demonstrated consistent visual generators across age and pattern. These results describe two novel VEP morphological patterns in typically developing children, but with similar underlying cortical sources. The importance of these morphological patterns is discussed in terms of future studies and the investigation of a relationship to visual cognitive performance. PMID:27445738

  17. The Correlation of Age and Postoperative Visual Acuity for Age-Related Cataract

    PubMed Central

    Li, Xiaochun; Cao, Xiaoguang; Hou, Xianru; Bao, Yongzhen

    2016-01-01

    Purpose. Clinically, what is the best time for age-related cataract (ARC) patients to receive surgeries and get the most benefits is important. We explored the relationship between age and presenting postoperative visual acuity (POVA) in patients from rural China. Methods. Three Lifeline Express Hospital Eye-Train missions of Peking University People's Hospital were chosen. At the first day after surgery, 3452 ARC eyes with the presenting POVA ≥ 6/60 were enrolled. The relationship between age and POVA was analyzed statistically. Results. In these three missions, there were more female patients than males; the ratio of females to males was 1.71. The average age of females was older than males. Overall, the percentages of patients with good visual outcomes (≥6/18) were significantly decreased with aging. Different regions had variations, but the trends were the same. There was weak linear correlation between age and POVA. The correlations of females were stronger than males in Yuncheng and Sanmenxia and weaker than males in Zhoukou. Conclusion. The good visual outcomes of presenting POVA were significantly decreased with aging and there were weak linear correlations between age and POVA in rural China. The linear correlation might be influenced by the difference of gender and region. PMID:26881225

  18. Age effects on visual-perceptual processing and confrontation naming.

    PubMed

    Gutherie, Audrey H; Seely, Peter W; Beacham, Lauren A; Schuchard, Ronald A; De l'Aune, William A; Moore, Anna Bacon

    2010-03-01

    The impact of age-related changes in visual-perceptual processing on naming ability has not been reported. The present study investigated the effects of 6 levels of spatial frequency and 6 levels of contrast on accuracy and latency to name objects in 14 young and 13 older neurologically normal adults with intact lexical-semantic functioning. Spatial frequency and contrast manipulations were made independently. Consistent with the hypotheses, variations in these two visual parameters impact naming ability in young and older subjects differently. The results from the spatial frequency-manipulations revealed that, in general, young vs. older subjects are faster and more accurate to name. However, this age-related difference is dependent on the spatial frequency on the image; differences were only seen for images presented at low (e.g., 0.25-1 c/deg) or high (e.g., 8-16 c/deg) spatial frequencies. Contrary to predictions, the results from the contrast manipulations revealed that overall older vs. young adults are more accurate to name. Again, however, differences were only seen for images presented at the lower levels of contrast (i.e., 1.25%). Both age groups had shorter latencies on the second exposure of the contrast-manipulated images, but this possible advantage of exposure was not seen for spatial frequency. Category analyses conducted on the data from this study indicate that older vs. young adults exhibit a stronger nonliving-object advantage for naming spatial frequency-manipulated images. Moreover, the findings suggest that bottom-up visual-perceptual variables integrate with top-down category information in different ways. Potential implications on the aging and naming (and recognition) literature are discussed. PMID:19670050

  19. Influence of aging on visual perception and visual motor integration in Korean adults.

    PubMed

    Kim, Eunhwi; Park, Young-Kyung; Byun, Yong-Hyun; Park, Mi-Sook; Kim, Hong

    2014-08-01

    This study investigated age-related changes of cognitive function in Korean adults using the Korean-Developmental Test of Visual Perception-2 (K-DTVP-2) and the Visual Motor Integration-3rd Revision (VMI-3R) test, and determined the main factors influencing VP and VMI in older adults. For this research, 139 adults for the K-DTVP-2 and 192 adults for the VMI-3R, from a total of 283 participants, were randomly and separately recruited in province, Korea. The present study showed that the mean score of the K-DTVP-2 and VMI-3R in 10-yr age increments significantly decreased as age increased (K-DTVP-2, F= 41.120, P< 0.001; VMI-3R, F= 16.583, P< 0.001). The mean score of the VMI-3R and K-DTVP-2 were significantly decreased in participants in their 50s compared to those in their 20s (P< 0.05). Age (t= -9.130, P< 0.001), gender (t= 3.029, P= 0.003), and the presence of diseases (t= -2.504, P= 0.013) were the significant factors affecting K-DTVP-2 score. On the other hand, age (t= -6.300, P< 0.001) was the only significant factor affecting VMI-3R score. K-DTVP-2 score (Standardized β= -0.611) decreased more sensitively with aging than VMI-3R (Standardized β= -0.467). The two measurements had a significant positive correlation (r = 0.855, P< 0.001). In conclusion, it can be suggested that VP and VMI should be regularly checked from an individual's 50s, which is a critical period for detecting cognitive decline by aging. Both the K-DTVP-2 and VMI-3R could be used for determining the level of cognitive deficit by aging. PMID:25210701

  20. Advanced age brings a greater reliance on visual feedback to maintain balance during walking.

    PubMed

    Franz, Jason R; Francis, Carrie A; Allen, Matthew S; O'Connor, Shawn M; Thelen, Darryl G

    2015-04-01

    We implemented a virtual reality system to quantify differences in the use of visual feedback to maintain balance during walking between healthy young (n=12, mean age: 24 years) and healthy old (n=11, 71 years) adults. Subjects walked on a treadmill while watching a speed-matched, virtual hallway with and without mediolateral visual perturbations. A motion capture system tracked center of mass (CoM) motion and foot kinematics. Spectral analysis, detrended fluctuation analysis, and local divergence exponents quantified old and young adults' dynamic response to visual perturbations. Old and young adults walked normally with comparable CoM spectral characteristics, lateral step placement temporal persistence, and local divergence exponents. Perturbed visual flow induced significantly larger changes in mediolateral CoM motion in old vs. young adults. Moreover, visual perturbations disrupted the control of lateral step placement and compromised local dynamic stability more significantly in old than young adults. Advanced age induces a greater reliance on visual feedback to maintain balance during waking, an effect that may compensate for degradations in somatosensation. Our findings are relevant to the early diagnosis of sensory-induced balance impairments and also point to the potential use of virtual reality to evaluate sensory rehabilitation and balance training programs for old adults. PMID:25687664

  1. Advanced age brings a greater reliance on visual feedback to maintain balance during walking

    PubMed Central

    Franz, Jason R.; Francis, Carrie A.; Allen, Matthew S.; O'Connor, Shawn M.; Thelen, Darryl G.

    2015-01-01

    We implemented a virtual reality system to quantify differences in the use of visual feedback to maintain balance during walking between healthy young (n = 12, mean age: 24 years) and healthy old (n = 11, 71 years) adults. Subjects walked on a treadmill while watching a speed-matched, virtual hallway with and without mediolateral visual perturbations. A motion capture system tracked center of mass (CoM) motion and foot kinematics. Spectral analysis, detrended fluctuation analysis, and local divergence exponents quantified old and young adults’ dynamic response to visual perturbations. Old and young adults walked normally with comparable CoM spectral characteristics, lateral step placement temporal persistence, and local divergence exponents. Perturbed visual flow induced significantly larger changes in mediolateral CoM motion in old vs. young adults. Moreover, visual perturbations disrupted the control of lateral step placement and compromised local dynamic stability more significantly in old than young adults. Advanced age induces a greater reliance on visual feedback to maintain balance during waking, an effect that may compensate for degradations in somatosensation. Our findings are relevant to the early diagnosis of sensory-induced balance impairments and also point to the potential use of virtual reality to evaluate sensory rehabilitation and balance training programs for old adults. PMID:25687664

  2. Neural Plasticity Underlying Visual Perceptual Learning in Aging

    PubMed Central

    Mishra, Jyoti; Rolle, Camarin; Gazzaley, Adam

    2014-01-01

    Healthy aging is associated with a decline in basic perceptual abilities, as well as higher-level cognitive functions such as working memory. In a recent perceptual training study using moving sweeps of Gabor stimuli, Berry et al. (2010) observed that older adults significantly improved discrimination abilities on the most challenging perceptual tasks that presented paired sweeps at rapid rates of 5 & 10 Hz. Berry et al. further showed that this perceptual training engendered transfer-of-benefit to an untrained working memory task. Here, we investigated the neural underpinnings of the improvements in these perceptual tasks, as assessed by event-related potential (ERP) recordings. Early visual ERP components time-locked to stimulus onset were compared pre- and post- training, as well as relative to a no-contact control group. The visual N1 and N2 components were significantly enhanced after training, and the N1 change correlated with improvements in perceptual discrimination on the task. Further, the change observed for the N1 and N2 was associated with the rapidity of the perceptual challenge; the visual N1 (120–150 ms) was enhanced post-training for 10 Hz sweep pairs, while the N2 (240–280 ms) was enhanced for the 5 Hz sweep pairs. We speculate that these observed post-training neural enhancements reflect improvements by older adults in the allocation of attention that is required to accurately dissociate perceptually overlapping stimuli when presented in rapid sequence. PMID:25218557

  3. Designing a visualization system for hydrological data

    NASA Astrophysics Data System (ADS)

    Fuhrmann, Sven

    2000-02-01

    The field of hydrology is, as any other scientific field, strongly affected by a massive technological evolution. The spread of modern information and communication technology within the last three decades has led to an increased collection, availability and use of spatial and temporal digital hydrological data. In a two-year research period a working group in Muenster applied and developed methods for the visualization of digital hydrological data and the documentation of hydrological models. A low-cost multimedial, hydrological visualization system (HydroVIS) for the Weser river catchment was developed. The research group designed HydroVIS under freeware constraints and tried to show what kind of multimedia visualization techniques can be effectively used with a nonprofit hydrological visualization system. The system's visual components include features such as electronic maps, temporal and nontemporal cartographic animations, the display of geologic profiles, interactive diagrams and hypertext, including photographs and tables.

  4. Systems biology of aging.

    PubMed

    Bolt, Kendra; Bergman, Aviv

    2015-01-01

    Human aging occurs at rates that vary widely between organisms and cell types. We hypothesize that in both cases, variation is due to differences in heat production, heat management and molecular susceptibility to heat-induced change. Metabolic rates have long been implored for their contributions to the aging process, with a negative correlation observed between basal metabolic rate and lifespan (Savage et al., Proc Natl Acad Sci U S A 104:4718–4723, 2007, Economos, Exp Gerontol 17:145–152, 1982, Keys et al., Metabolism 22:579–587, 1973, O’Connor et al., Comp Biochem Physiol Part A, Molr & Integr Physiol 133:835–842, 2002, Speakman, J Exp Biol 208:1717–1730, 2005, Poehlman, J Am Geriatrics Soc 41:552–559, 1993). Small amounts of heat are the well-known byproduct of metabolism and other biological processes, and despite their magnitude, are sufficient to elicit alterations in biomolecular characteristics (Somero, Ann Rev Physiol 57:43–68, 1995). Existing theories of aging suggest that damage occurs to the conformations or sequences of molecules, which only shifts focus onto the implied failure of repair mechanisms. Contrarily, heat-induced changes affect the behavioral characteristics of molecules and are thus able to persist “under the radar” of heat shock proteins and other canalizing mechanisms, which recognize only physical aberrancies (Rutherford and Lindquist, Nature 396:336–342, 1998, Siegal and Bergman, Proc Natl Acad Sci U S A 99:10528–10532, 2002, Waddington, Nature 150:563–565, 1942). According to our hypothesis, behavioral changes to the binding affinities, kinetics, motilities, and functionalities are dependent on minute energetic fields within and between molecules. Exposure to the thermal byproducts of metabolism cause heritable shifts in molecular interaction schemes and diminish the integrity of genetic and epigenetic networks. Restructured topologies alter the emergent properties of networks and are observed as the

  5. Characteristics of flight simulator visual systems

    NASA Technical Reports Server (NTRS)

    Statler, I. C. (Editor)

    1981-01-01

    The physical parameters of the flight simulator visual system that characterize the system and determine its fidelity are identified and defined. The characteristics of visual simulation systems are discussed in terms of the basic categories of spatial, energy, and temporal properties corresponding to the three fundamental quantities of length, mass, and time. Each of these parameters are further addressed in relation to its effect, its appropriate units or descriptors, methods of measurement, and its use or importance to image quality.

  6. [Age-related changes of sensory system].

    PubMed

    Iwamoto, Toshihiko; Hanyu, Haruo; Umahara, Takahiko

    2013-10-01

    Pathological processes usually superimpose on physiological aging even in the sensory system including visual, hearing, olfactory, taste and somatosensory functions. Representative changes of age-related changes are presbyopia, cataracts, and presbyacusis. Reduced sense of smell is seen in normal aging, but the prominent reduction detected by the odor stick identification test is noticed especially in early stage of Alzheimer or Parkinson disease. Reduced sense of taste is well-known especially in salty sense, while the changes of sweet, bitter, and sour tastes are different among individuals. Finally, deep sensation of vibration and proprioception is decreased with age as well as superficial sensation (touch, temperature, pain). As a result, impaired sensory system could induce deterioration of the activities of daily living and quality of life in the elderly. PMID:24261198

  7. An interpersonal multimedia visualization system

    SciTech Connect

    Phillips, R.L.

    1990-01-01

    Media View is a computer program that provides a generic infrastructure for authoring and interacting with multimedia documents. Among its many applications is the ability to furnish a user with a comprehensive environment for analysis and visualization. With MediaView the user produces a document'' that contains mathematics, datasets and associated visualizations. From the dataset or embedded mathematics animated sequences can be produced in situ. The mathematical content of the document'' can be explored through manipulation with Mathematica {trademark}. Since the document'' is all digital, it can be shared with a co-worker on a local network or mailed electronically to a colleague at a distant site. Animations and any other substructure of the document'' persist through the mailing process and can be awakened at the destination by the recipient. 5 refs., 4 figs.

  8. Neural plasticity underlying visual perceptual learning in aging.

    PubMed

    Mishra, Jyoti; Rolle, Camarin; Gazzaley, Adam

    2015-07-01

    Healthy aging is associated with a decline in basic perceptual abilities, as well as higher-level cognitive functions such as working memory. In a recent perceptual training study using moving sweeps of Gabor stimuli, Berry et al. (2010) observed that older adults significantly improved discrimination abilities on the most challenging perceptual tasks that presented paired sweeps at rapid rates of 5 and 10 Hz. Berry et al. further showed that this perceptual training engendered transfer-of-benefit to an untrained working memory task. Here, we investigated the neural underpinnings of the improvements in these perceptual tasks, as assessed by event-related potential (ERP) recordings. Early visual ERP components time-locked to stimulus onset were compared pre- and post-training, as well as relative to a no-contact control group. The visual N1 and N2 components were significantly enhanced after training, and the N1 change correlated with improvements in perceptual discrimination on the task. Further, the change observed for the N1 and N2 was associated with the rapidity of the perceptual challenge; the visual N1 (120-150 ms) was enhanced post-training for 10 Hz sweep pairs, while the N2 (240-280 ms) was enhanced for the 5 Hz sweep pairs. We speculate that these observed post-training neural enhancements reflect improvements by older adults in the allocation of attention that is required to accurately dissociate perceptually overlapping stimuli when presented in rapid sequence. This article is part of a Special Issue entitled SI: Memory Å. PMID:25218557

  9. Solar System Visualization: Global Science Maps

    NASA Technical Reports Server (NTRS)

    DeJong, E. M.

    1994-01-01

    The goal of the Solar System Visualization (SSV) project is to re-explore the planets using the data from previous National Aeronautics and Space Administration (NASA) planetary missions on and public information.

  10. [Contrast transfer function of the visual system].

    PubMed

    Pak, M A; Cleveland, S J

    1991-09-01

    Visually evoked potentials were used to determine the spatial contrast response function of the visual system and the visual acuity of the pigeon. The spatial contrast response describes the relationship between the contrast in a pattern of vertical stripes, whose luminance is a function of position, and the amplitude of the visually evoked response at various spatial frequencies for a given temporal frequency (pattern reversal frequency); it indicates how particular spatial frequencies are attenuated in the visual system. The visually evoked responses were recorded using monopolar stainless steel electrodes inserted into the stratum griseum superficiale of the optic tectum; the depth of penetration was determined on the basis of a stereotactic atlas. The stimulus patterns were generated on a video monitor placed 75 cm in front of the animal's eye perpendicular to the optic axis. The spatial contrast response function measured at 10% contrast and 0.5 Hz reversal frequency shows a peak at a spatial frequency of 0.5 c/deg, corresponding to 1 degree of visual angle, and decreases progressively at higher spatial frequencies. The high-frequency limit (cut-off frequency) for resolution of sinusoidal gratings, estimated from the contrast response function, is 15.5 c/deg, corresponding to a visual acuity of 1.9 min of arc. PMID:1657228

  11. Using Visualization in Cockpit Decision Support Systems

    SciTech Connect

    Aragon, Cecilia R.

    2005-07-01

    In order to safely operate their aircraft, pilots must makerapid decisions based on integrating and processing large amounts ofheterogeneous information. Visual displays are often the most efficientmethod of presenting safety-critical data to pilots in real time.However, care must be taken to ensure the pilot is provided with theappropriate amount of information to make effective decisions and notbecome cognitively overloaded. The results of two usability studies of aprototype airflow hazard visualization cockpit decision support systemare summarized. The studies demonstrate that such a system significantlyimproves the performance of helicopter pilots landing under turbulentconditions. Based on these results, design principles and implicationsfor cockpit decision support systems using visualization arepresented.

  12. Age-related changes in the attentional control of visual cortex: A selective problem in the left visual hemifield

    PubMed Central

    Nagamatsu, Lindsay S.; Carolan, Patrick; Liu-Ambrose, Teresa Y.L.; Handy, Todd C.

    2012-01-01

    To what extent does our visual-spatial attention change with age? In this regard, it has been previously reported that relative to young controls, seniors show delays in attention-related sensory facilitation. Given this finding, our study was designed to examine two key questions regarding age-related changes in the effect of spatial attention on sensory-evoked responses in visual cortex –– are there visual field differences in the age-related impairments in sensory processing, and do these impairments co-occur with changes in the executive control signals associated with visual spatial orienting? Therefore, our study examined both attentional control and attentional facilitation in seniors (aged 66 to 74 years) and young adults (aged 18 to 25 years) using a canonical spatial orienting task. Participants responded to attended and unattended peripheral targets while we recorded event-related potentials (ERPs) to both targets and attention-directing spatial cues. We found that not only were sensory-evoked responses delayed in seniors specifically for unattended events in the left visual field as measured via latency shifts in the lateral occipital P1 elicited by visual targets, but seniors also showed amplitude reductions in the anterior directing attentional negativity (ADAN) component elicited by cues directing attention to the left visual field. At the same time, seniors also had significantly higher error rates for targets presented in the left vs. right visual field. Taken together, our data thus converge on the conclusion that age-related changes in visual spatial attention involve both sensory-level and executive attentional control processes, and that these effects appear to be strongly associated with the left visual field. PMID:21356222

  13. Hybrid system modeling, simulation, and visualization: a crane system

    NASA Astrophysics Data System (ADS)

    Hiniduma Udugama Gamage, Sahan S.; Palmer, Patrick R.

    2003-08-01

    Modeling and visualization of a complex hybrid system with different domains of energy flow and signal flow are described in this paper. It is a crane system situated in a barge complete with the load, electrical power, drive and control systems. A dynamically and functionally accurate model of the crane was developed. The implementation is in the freely available software suit of Virtual Test Bed (VTB) for simulation and Visual Extension Engine (VXE) for visualization. The bidirectional interaction of simulator and visualizer is fully utilized in this application. The further challenges confronted in implementing this particular system and any other complex system are discussed and possible solutions are suggested.

  14. Earth orbital teleoperator visual system evaluation program

    NASA Technical Reports Server (NTRS)

    Shields, N. L., Jr.; Kirkpatrick, M., III; Frederick, P. N.; Malone, T. B.

    1975-01-01

    Empirical tests of range estimation accuracy and resolution, via television, under monoptic and steroptic viewing conditions are discussed. Test data are used to derive man machine interface requirements and make design decisions for an orbital remote manipulator system. Remote manipulator system visual tasks are given and the effects of system parameters of these tasks are evaluated.

  15. [Review of visual display system in flight simulator].

    PubMed

    Xie, Guang-hui; Wei, Shao-ning

    2003-06-01

    Visual display system is the key part and plays a very important role in flight simulators and flight training devices. The developing history of visual display system is recalled and the principle and characters of some visual display systems including collimated display systems and back-projected collimated display systems are described. The future directions of visual display systems are analyzed. PMID:12934618

  16. Towards reasoning visualization in expert systems

    NASA Technical Reports Server (NTRS)

    Selig, William John; Johannes, James D.

    1989-01-01

    Preliminary results are presented of ongoing research to develop visualization paradigms for expert systems reasoning processes. The results are based in part on a prototype implementation that is being developed to visualize the reasoning processes of a rule-based forward chaining expert system. The research is based on the premise that the presentation of information at the highest applicable conceptual level will enhance the assimilation of that information. Hierarchical levels in both the syntactic and semantic levels of reasoning in expert systems are described in detail.

  17. Visual systems - The state of the art

    NASA Astrophysics Data System (ADS)

    Shorrock, David

    State-of-the-art, computer-generated image simulator visual systems typically encompass a data base which generates the model of the operating environment, an image generator, and a display system suitable for the applications envisaged. Two basic approaches to such systems are discernible: those employing hybrid raster/calligraphy and those using raster/continuous tone. Attention is presently given to such capabilities and elements of visual displays as texture effects, transparencies, fade level-of-detail management, animation effects, and image generator functions for daylight and night/dusk conditions, as well as prospective developments in this field.

  18. Thematic World Wide Web Visualization System

    Energy Science and Technology Software Center (ESTSC)

    1996-10-10

    WebTheme is a system designed to facilitate world wide web information access and retrieval through visualization. It consists of two principal pieces, a WebTheme Server which allows users to enter in a query and automatocally harvest and process information of interest, and a WebTheme browser, which allows users to work with both Galaxies and Themescape visualizations of their data within a JAVA capable world wide web browser. WebTheme is an Internet solution, meaning that accessmore » to the server and the resulting visualizations can all be performed through the use of a WWW browser. This allows users to access and interact with SPIRE (Spatial Paradigm for Information Retrieval and Exploration) based visualizations through a web browser regardless of what computer platforms they are running on. WebTheme is specifically designed to create databases by harvesting and processing WWW home pages available on the Internet.« less

  19. Reduction in the retinotopic early visual cortex with normal aging and magnitude of perceptual learning

    PubMed Central

    Chang, Li-Hung; Yotsumoto, Yuko; Salat, David H.; Andersen, George J.; Watanabe, Takeo; Sasaki, Yuka

    2014-01-01

    While normal aging is known to reduce cortical structures globally, the effects of aging on local structures and functions of early visual cortex are less understood. Here, using standard retinotopic mapping and magnetic resonance imaging (MRI) morphological analyses, we investigated whether aging affects areal size of the early visual cortex, which were retinotopically localized, and whether those morphological measures were associated with individual performance on visual perceptual learning. First, significant age-associated reduction was found in the areal size of V1, V2, and V3. Second, individual ability of visual perceptual learning was significantly correlated with areal size of V3 in older adults. These results demonstrate that aging changes local structures of the early visual cortex and the degree of change may be associated with individual visual plasticity. PMID:25277041

  20. Visual Tutoring System for Programming Multiprocessor Networks.

    ERIC Educational Resources Information Center

    Trichina, Elena

    1996-01-01

    Describes a visual tutoring system for programming distributive-memory multiprocessor networks. Highlights include difficulties of parallel programming, and three instructional modes in the system, including a hypertext-like lecture, a question-answer mode, and an expert aid mode. (Author/LRW)

  1. Rehabilitation and Visual Impairment: A Human System.

    ERIC Educational Resources Information Center

    Vander Kolk, Charles J.

    1982-01-01

    The rehabilitation of visually impaired persons can be conceptualized by a human systems approach. This paper explaines seven levels of human systems, related factors, and 10 assumptions that lead to high standards for rehabilitation workers and organizations. The concepts are applied to work with clients and use in rehabilitation agencies.…

  2. Transformation of visual direction requires the cognitive visual system

    NASA Astrophysics Data System (ADS)

    Bridgeman, Bruce

    2001-06-01

    We differentiate a cognitive branch of the visual system form a sensorimotor branch with the Roelofs effect, a perception that a target's position is biased in the direction opposite the offset of a surrounding fame. When a small fixed target is presented inside a frame that is offset to one side, normal humans perceive the target to be deviated in the direction opposite the frame's offset. They can still jab the target accurately, however, even though it is perceptually mislocalized. This dissociation indicates that motor coordinates are coded in a 'sensorimotor', possibly dorsal, pathway containing visual information that can be inconsistent with perceived information in a 'cognitive', possibly ventral pathway. Lack of a Roelofs effect indicates use of information in the sensorimotor pathway, independent from perception. We ask whether the sensorimotor pathway can handle a transformation of target position, in an anti-jabbing task analogous to anti-saccade tasks: the observer jabs a position symmetrically opposite the target's position, relative to the midline of the head. A 1 deg left or right. Observers were to jab the symmetrically opposite position as soon as the target disappeared. The result was a large and consistent Roelofs effect for an open-loop motor task, indicating that information from the cognitive pathway must be used to perform this task.

  3. Using Visualization in Cockpit Decision Support Systems

    NASA Technical Reports Server (NTRS)

    Aragon, Cecilia R.

    2005-01-01

    In order to safely operate their aircraft, pilots must make rapid decisions based on integrating and processing large amounts of heterogeneous information. Visual displays are often the most efficient method of presenting safety-critical data to pilots in real time. However, care must be taken to ensure the pilot is provided with the appropriate amount of information to make effective decisions and not become cognitively overloaded. The results of two usability studies of a prototype airflow hazard visualization cockpit decision support system are summarized. The studies demonstrate that such a system significantly improves the performance of helicopter pilots landing under turbulent conditions. Based on these results, design principles and implications for cockpit decision support systems using visualization are presented.

  4. Visual system for automatic car registration

    NASA Astrophysics Data System (ADS)

    Altamirano-Robles, Leopoldo; Arias-Estrada, Miguel; Lopez-Lopez, Aurelio; Lemuz-Lopez, Rafael

    2001-04-01

    In this paper we propose a system for capturing and processing car identification labels. The system captures the required images for the registration process using a CCD camera with an appropriate mount. Images are analyzed and stored by the system, generating a report, where all the captured visual information is included. The information is further stored in a way, that allows the retrieval of each report. Results and discussion about the system are presented.

  5. Earth orbital teleoperator visual system evaluation program

    NASA Technical Reports Server (NTRS)

    Frederick, P. N.; Shields, N. L., Jr.; Kirkpatrick, M., III

    1977-01-01

    Visual system parameters and stereoptic television component geometries were evaluated for optimum viewing. The accuracy of operator range estimation using a Fresnell stereo television system with a three dimensional cursor was examined. An operator's ability to align three dimensional targets using vidicon tube and solid state television cameras as part of a Fresnell stereoptic system was evaluated. An operator's ability to discriminate between varied color samples viewed with a color television system was determined.

  6. Age-related changes in the visual pathways: blame it on the axon.

    PubMed

    Calkins, David J

    2013-12-01

    The aging visual system is marked by a decline in some, but not all, key functions. Some of this decline is attributed to changes in the optics of the eye, but other aspects must have a neural basis. Across mammals, with aging there is remarkable persistence of central structures to which retinal ganglion cell (RGC) axons project with little or no loss of neurons. Similarly, RGC bodies in the retina are subject to variable age-related loss, with most mammals showing none over time. In contrast, the RGC axon itself is highly vulnerable. Across species, the rate of axon loss in the optic nerve is related inversely to the total number of axons at maturity and lifespan. The result of this scaling is approximately a 40% total decline in axon number. Evidence suggests that the consistent vulnerability of RGC axons to aging arises from their high metabolic demand combined with diminishing resources. Thus, therapeutic interventions that conserve bioenergetics may have potential to abate age-related decline in visual function. PMID:24335066

  7. Visualization tool for advanced laser system development

    NASA Astrophysics Data System (ADS)

    Crockett, Gregg A.; Brunson, Richard L.

    2002-06-01

    Simulation development for Laser Weapon Systems design and system trade analyses has progressed to new levels with the advent of object-oriented software development tools and PC processor capabilities. These tools allow rapid visualization of upcoming laser weapon system architectures and the ability to rapidly respond to what-if scenario questions from potential user commands. These simulations can solve very intensive problems in short time periods to investigate the parameter space of a newly emerging weapon system concept, or can address user mission performance for many different scenario engagements. Equally important to the rapid solution of complex numerical problems is the ability to rapidly visualize the results of the simulation, and to effectively interact with visualized output to glean new insights into the complex interactions of a scenario. Boeing has applied these ideas to develop a tool called the Satellite Visualization and Signature Tool (SVST). This Windows application is based upon a series of C++ coded modules that have evolved from several programs at Boeing-SVS. The SVST structure, extensibility, and some recent results of applying the simulation to weapon system concepts and designs will be discussed in this paper.

  8. Integrated voice and visual systems research topics

    NASA Technical Reports Server (NTRS)

    Williams, Douglas H.; Simpson, Carol A.

    1986-01-01

    A series of studies was performed to investigate factors of helicopter speech and visual system design and measure the effects of these factors on human performance, both for pilots and non-pilots. The findings and conclusions of these studies were applied by the U.S. Army to the design of the Army's next generation threat warning system for helicopters and to the linguistic functional requirements for a joint Army/NASA flightworthy, experimental speech generation and recognition system.

  9. Energy metabolism of the visual system

    PubMed Central

    Wong-Riley, Margaret T.T.

    2012-01-01

    The visual system is one of the most energetically demanding systems in the brain. The currency of energy is ATP, which is generated most efficiently from oxidative metabolism in the mitochondria. ATP supports multiple neuronal functions. Foremost is repolarization of the membrane potential after depolarization. Neuronal activity, ATP generation, blood flow, oxygen consumption, glucose utilization, and mitochondrial oxidative metabolism are all interrelated. In the retina, phototransduction, neurotransmitter utilization, and protein/organelle transport are energy-dependent, yet repolarization-after-depolarization consumes the bulk of the energy. Repolarization in photoreceptor inner segments maintains the dark current. Repolarization by all neurons along the visual pathway following depolarizing excitatory glutamatergic neurotransmission preserves cellular integrity and permits reactivation. The higher metabolic activity in the magno- versus the parvo-cellular pathway, the ON- versus the OFF-pathway in some (and the reverse in other) species, and in specialized functional representations in the visual cortex all reflect a greater emphasis on the processing of specific visual attributes. Neuronal activity and energy metabolism are tightly coupled processes at the cellular and even at the molecular levels. Deficiencies in energy metabolism, such as in diabetes, mitochondrial DNA mutation, mitochondrial protein malfunction, and oxidative stress can lead to retinopathy, visual deficits, neuronal degeneration, and eventual blindness. PMID:23226947

  10. Visualizing Terrestrial and Aquatic Systems in 3D

    EPA Science Inventory

    The need for better visualization tools for environmental science is well documented, and the Visualization for Terrestrial and Aquatic Systems project (VISTAS) aims to both help scientists produce effective environmental science visualizations and to determine which visualizatio...

  11. Maturation of Visual and Auditory Temporal Processing in School-Aged Children

    ERIC Educational Resources Information Center

    Dawes, Piers; Bishop, Dorothy V. M.

    2008-01-01

    Purpose: To examine development of sensitivity to auditory and visual temporal processes in children and the association with standardized measures of auditory processing and communication. Methods: Normative data on tests of visual and auditory processing were collected on 18 adults and 98 children aged 6-10 years of age. Auditory processes…

  12. AGING SYSTEM DESIGN DEVELOPMENT STRATEGY

    SciTech Connect

    J. Beesley

    2005-02-07

    This plan provides an overview, work to date, and the path forward for the design development strategy of the Aging cask for aging commercial spent nuclear fuel (CSNF) at the Yucca Mountain Project (YMP) repository site. Waste for subsurface emplacement at the repository includes US Department of Energy (DOE) high-level radioactive waste (HLW), DOE SNF, commercial fuel in dual-purpose canisters (DPCs), uncanistered bare fuel, naval fuel, and other waste types. Table 1-1 lists the types of radioactive materials that may be aged at YMP, and those materials that will not be placed in an aging cask or module. This plan presents the strategy for design development of the Aging system. The Aging system will not handle naval fuel, DOE HLW, MCOs, or DOE SNF since those materials will be delivered to the repository in a state and sequence that allows them to be placed into waste packages for emplacement. Some CSNF from nuclear reactors, especially CSNF that is thermally too hot for emplacement underground, will need to be aged at the repository.

  13. Visual navigation system for autonomous indoor blimps

    NASA Astrophysics Data System (ADS)

    Campos, Mario F.; de Souza Coelho, Lucio

    1999-07-01

    Autonomous dirigibles - aerial robots that are a blimp controlled by computer based on information gathered by sensors - are a new and promising research field in Robotics, offering several original work opportunities. One of them is the study of visual navigation of UAVs. In the work described in this paper, a Computer Vision and Control system was developed to perform automatically very simple navigation task for a small indoor blimp. The vision system is able to track artificial visual beacons - objects with known geometrical properties - and from them a geometrical methodology can extract information about orientation of the blimp. The tracking of natural landmarks is also a possibility for the vision technique developed. The control system uses that data to keep the dirigible on a programmed orientation. Experimental results showing the correct and efficient functioning of the system are shown and have your implications and future possibilities discussed.

  14. Dependency visualization for complex system understanding

    SciTech Connect

    Smart, J.A.C.

    1994-09-01

    With the volume of software in production use dramatically increasing, the importance of software maintenance has become strikingly apparent. Techniques now sought and developed for reverse engineering and design extraction and recovery. At present, numerous commercial products and research tools exist which are capable of visualizing a variety of programming languages and software constructs. The list of new tools and services continues to grow rapidly. Although the scope of the existing commercial and academic product set is quite broad, these tools still share a common underlying problem. The ability of each tool to visually organize object representations is increasingly impaired as the number of components and component dependencies within systems increases. Regardless of how objects are defined, complex ``spaghetti`` networks result in nearly all large system cases. While this problem is immediately apparent in modem systems analysis involving large software implementations, it is not new. As will be discussed in Chapter 2, related problems involving the theory of graphs were identified long ago. This important theoretical foundation provides a useful vehicle for representing and analyzing complex system structures. While the utility of directed graph based concepts in software tool design has been demonstrated in literature, these tools still lack the capabilities necessary for large system comprehension. This foundation must therefore be expanded with new orgnizational and visualization constructs necessary to meet this challenge. This dissertation addresses this need by constructing a conceptual model and a set of methods for interactively exploring, organizing, and understanding the structure of complex software systems.

  15. Visualizing systems engineering data with Java

    SciTech Connect

    Barter, Robert H.; Vinzant, Aleta

    1998-11-10

    Systems Engineers are required to deal with complex sets of data. To be useful, the data must be managed effectively, and presented in meaningful terms to a wide variety of information consumers. Two software patterns are presented as the basis for exploring the visualization of systems engineering data. The Model, View, Controller pattern defines an information management system architecture. The Entity, Relation, Attribute pattern defines the information model. MVC "Views" then form the basis for the user interface between the information consumer and the MVC "Controller"/"Model" combination. A Java tool set is described for exploring alternative views into the underlying complex data structures encountered in systems engineering.

  16. Foundations of Advanced Information Visualization for Visual Information (Retrieval) Systems.

    ERIC Educational Resources Information Center

    Rorvig, Mark; Hemmje, Matthias

    1999-01-01

    Reports on a conference workshop that addressed Visual Information Retrieval Interfaces (VIRIs). Topics include evaluation methods; task dimension for evaluating VIRIs; efforts to fund European development of VIRIs; metrics, including cosine vector; navigation among documents; and interactions with users. (LRW)

  17. Mobile visual examination and repackaging (MOVER) system

    SciTech Connect

    Los Alamos National Laboratory

    2001-01-01

    Process engineering and waste technology teams at LOS Alamos National Laboratory delivered a prototype Mobile Visual Examination and Repackaging (MOVER) system to the Waste Isolation Pilot Plant (WIPP) outside of Carlsbad, NM in October, 2000. This system was developed in response to compliance issues with legacy waste that was packaged in 55 gallons drums prior to release of WIPP's waste acceptance criteria (WAC). A statistical percentage of these 55 gallon drums will be opened and visually examined (VE) as part of re-characterization using Non-destructive examination (NDE) procedures. VE is an intrusive technique since the drum is opened, and as a result, there are more risks in spreading contamination. Hence, VE is performed in a glovebox to protect the workers and the environment. During VE, waste is pulled out of one drum, visually examined, the amount of plutonium measured if necessary, and the waste repackaged into one or more drums. MOVER can perform all these operations, along with having the capability to house the glovebox operations and all support equipment in a 40-foot-long container that can be transported to a site on a semi-trailer. This container is divided into three rooms, providing the level of safety and containment of a fixed facility. A key asset of mobile systems is the inherent need for modular design that reduces infrastructure costs and overhead. A mobile system like MOVER represents a technology base aimed at meeting DOE schedules to accelerate decommissioning of many sites.

  18. Visually Exploring Worldwide Incidents Tracking System Data

    SciTech Connect

    Chhatwal, Shree D.; Rose, Stuart J.

    2008-01-27

    This paper presents refinements of an existing analytic tool, Juxter, which was developed for the visualization of multi-dimensional categorical data, and explores its application to support exploration and interaction with open source Worldwide Incidents Tracking System (WITS) data. The volume and complexity of data available on terrorism makes it hard to analyze. Information systems that can efficiently and effectively collect, access, analyze, and report terrorist incidents can help in further studies focused on preventing, detecting, and responding to terrorist attacks. Existing interfaces to the WITS data support advanced search capabilities, and geolocation but lack functionality for identifying patterns and trends. To better support efficient browsing we have refined Juxter’s existing capabilities for filtering, selecting, and sorting elements and categories within the visualization.

  19. Early screening of an infant's visual system

    NASA Astrophysics Data System (ADS)

    Costa, Manuel F. M.; Jorge, Jorge M.

    1999-06-01

    It is of utmost importance to the development of the child's visual system that she perceives clear focused retinal images. Furthermore if the refractive problems are not corrected in due time amblyopia may occur--myopia and hyperopia can only cause important problems in the future when they are significantly large, however for the astigmatism (rather frequent in infants) and anisometropia the problems tend to be more stringent. The early evaluation of the visual status of human infants is thus of critical importance. Photorefraction is a convenient technique for this kind of subjects. Essentially a light beam is delivered into the eyes. It is refracted by the ocular media, strikes the retina, focusing or not, reflects off and is collected by a camera. The photorefraction setup we established using new technological breakthroughs on the fields of imaging devices, digital image processing and fiber optics, allows a fast noninvasive evaluation of children visual status (refractive errors, accommodation, strabismus, ...). Results of the visual screening of a group of risk' child descents of blinds or amblyopes will be presented.

  20. A Space and Atmospheric Visualization Science System

    NASA Technical Reports Server (NTRS)

    Szuszczewicz, E. P.; Blanchard, P.; Mankofsky, A.; Goodrich, C.; Kamins, D.; Kulkarni, R.; Mcnabb, D.; Moroh, M.

    1994-01-01

    SAVS (a Space and Atmospheric Visualization Science system) is an integrated system with user-friendly functionality that employs a 'push-button' software environment that mimics the logical scientific processes in data acquisition, reduction, analysis, and visualization. All of this is accomplished without requiring a detailed understanding of the methods, networks, and modules that link the tools and effectively execute the functions. This report describes SAVS and its components, followed by several applications based on generic research interests in interplanetary and magnetospheric physics (IMP/ISTP), active experiments in space (CRRES), and mission planning focused on the earth's thermospheric, ionospheric, and mesospheric domains (TIMED). The final chapters provide a user-oriented description of interface functionalities, hands-on operations, and customized modules, with details of the primary modules presented in the appendices. The overall intent of the report is to reflect the accomplishments of the three-year development effort and to introduce potential users to the power and utility of the integrated data acquisition, analysis, and visualization system.

  1. Influence of loupes and age on the near visual acuity of practicing dentists

    NASA Astrophysics Data System (ADS)

    Eichenberger, Martina; Perrin, Philippe; Neuhaus, Klaus W.; Bringolf, Ueli; Lussi, Adrian

    2011-03-01

    We evaluated the near visual acuity of 40 dentists and its improvement by using different magnification devices. The acuity was tested with miniaturized E-optotype tests on a negatoscope under the following conditions: 1. natural visual acuity, 300 mm; 2. single lens loupe, 2×, 250 mm; 3. Galilean loupe, 2.5×, 380 mm; and 4. Keplerian loupe, 4.3×, 400 mm. In part 1, the influence of the magnification devices was investigated for all dentists. The Keplerian loupe obtained the highest visual acuity (4.64), followed by the Galilean loupe (2.43), the single lens loupe (1.42), and natural visual acuity (1.19). For part 2, the dentists were classified according to their age (=40 years). The younger dentists' group achieved a significantly higher visual acuity with all magnification devices (p<0.001). For part 3, the dentists were grouped according to their natural visual acuity. The group with the higher natural visual acuity achieved significantly higher visual acuity with all magnification devices than did the group of dentists with the lower natural visual acuity (p<0.01). It can be concluded that near visual acuity varies highly between individuals and decreases during the lifetime. Independent of age or natural vision, visual acuity can be significantly improved by using magnification devices.

  2. 47 CFR 87.483 - Audio visual warning systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Audio visual warning systems. 87.483 Section 87... AVIATION SERVICES Stations in the Radiodetermination Service § 87.483 Audio visual warning systems. An audio visual warning system (AVWS) is a radar-based obstacle avoidance system. AVWS...

  3. A Steady State Visually Evoked Potential Investigation of Memory and Ageing

    ERIC Educational Resources Information Center

    Macpherson, Helen; Pipingas, Andrew; Silberstein, Richard

    2009-01-01

    Old age is generally accompanied by a decline in memory performance. Specifically, neuroimaging and electrophysiological studies have revealed that there are age-related changes in the neural correlates of episodic and working memory. This study investigated age-associated changes in the steady state visually evoked potential (SSVEP) amplitude and…

  4. Child and Symbol Factors in Learning to Read a Visually Complex Writing System

    ERIC Educational Resources Information Center

    Nag, Sonali; Snowling, Margaret; Quinlan, Philip; Hulme, Charles

    2014-01-01

    In Kannada, visual features are arranged in blocks called "akshara," making this a visually more complex writing system than typical alphabetic orthographies. Akshara knowledge was assessed concurrently and 8 months later in 113 children in the first years of reading instruction (aged 4-7 years). Mixed effects logistic regression models…

  5. Video stabilization based on human visual system

    NASA Astrophysics Data System (ADS)

    Lee, Yun Gu

    2014-09-01

    A video stabilization method based on a new concept inspired by the human visual system is presented. The human eye provides a stable scene by continuously changing the eye's orientation in a way that always places the focused target in the center of one's view. Similar to the human eye, the proposed algorithm focuses only on a single target object within a scene and stabilizes the target on the two-dimensional image plane by rotating a camera in three-dimensional space while most previous methods consider all objects in a video. The rotational angles of the camera along the x and y axes are simply predicted from a translational motion vector of the target object on the image plane. Hence, the proposed algorithm can provide a vivid video as if it was seen through the eye. Efficient video stabilization by approximating the human visual system is introduced, a practical method for real-time devices. Experimental results demonstrate that the visual feelings of the compensated videos are different depending on the selected target object and the approximating method provides a reasonable performance.

  6. Image quality assessment and human visual system

    NASA Astrophysics Data System (ADS)

    Gao, Xinbo; Lu, Wen; Tao, Dacheng; Li, Xuelong

    2010-07-01

    This paper summaries the state-of-the-art of image quality assessment (IQA) and human visual system (HVS). IQA provides an objective index or real value to measure the quality of the specified image. Since human beings are the ultimate receivers of visual information in practical applications, the most reliable IQA is to build a computational model to mimic the HVS. According to the properties and cognitive mechanism of the HVS, the available HVS-based IQA methods can be divided into two categories, i.e., bionics methods and engineering methods. This paper briefly introduces the basic theories and development histories of the above two kinds of HVS-based IQA methods. Finally, some promising research issues are pointed out in the end of the paper.

  7. SNF AGING SYSTEM DESCRIPTION DOCUMENT

    SciTech Connect

    L.L. Swanson

    2005-04-06

    The purpose of this system description document (SDD) is to establish requirements that drive the design of the spent nuclear fuel (SNF) aging system and associated bases, which will allow the design effort to proceed. This SDD will be revised at strategic points as the design matures. This SDD identifies the requirements and describes the system design, as it currently exists, with emphasis on attributes of the design provided to meet the requirements. This SDD is an engineering tool for design control; accordingly, the primary audience and users are design engineers. This SDD is part of an iterative design process. It leads the design process with regard to the flow down of upper tier requirements onto the system. Knowledge of these requirements is essential in performing the design process. The SDD follows the design with regard to the description of the system. The description provided in the SDD reflects the current results of the design process. Throughout this SDD, the term aging cask applies to vertical site-specific casks and to horizontal aging modules. The term overpack is a vertical site-specific cask that contains a dual-purpose canister (DPC) or a disposable canister. Functional and operational requirements applicable to this system were obtained from ''Project Functional and Operational Requirements'' (F&OR) (Curry 2004 [DIRS 170557]). Other requirements that support the design process were taken from documents such as ''Project Design Criteria Document'' (PDC) (BSC 2004 [DES 171599]), ''Site Fire Hazards Analyses'' (BSC 2005 [DIRS 172174]), and ''Nuclear Safety Design Bases for License Application'' (BSC 2005 [DIRS 171512]). The documents address requirements in the ''Project Requirements Document'' (PRD) (Canori and Leitner 2003 [DIRS 166275]). This SDD includes several appendices. Appendix A is a Glossary; Appendix B is a list of key system charts, diagrams, drawings, lists and additional supporting information; and Appendix C is a list of

  8. Effects of aging on pointing movements under restricted visual feedback conditions.

    PubMed

    Zhang, Liancun; Yang, Jiajia; Inai, Yoshinobu; Huang, Qiang; Wu, Jinglong

    2015-04-01

    The goal of this study was to investigate the effects of aging on pointing movements under restricted visual feedback of hand movement and target location. Fifteen young subjects and fifteen elderly subjects performed pointing movements under four restricted visual feedback conditions that included full visual feedback of hand movement and target location (FV), no visual feedback of hand movement and target location condition (NV), no visual feedback of hand movement (NM) and no visual feedback of target location (NT). This study suggested that Fitts' law applied for pointing movements of the elderly adults under different visual restriction conditions. Moreover, significant main effect of aging on movement times has been found in all four tasks. The peripheral and central changes may be the key factors for these different characteristics. Furthermore, no significant main effects of age on the mean accuracy rate under condition of restricted visual feedback were found. The present study suggested that the elderly subjects made a very similar use of the available sensory information as young subjects under restricted visual feedback conditions. In addition, during the pointing movement, information about the hand's movement was more useful than information about the target location for young and elderly subjects. PMID:25506638

  9. Age, Sex, and Verbal Abilities Affect Location of Linguistic Connectivity in Ventral Visual Pathway

    ERIC Educational Resources Information Center

    Burman, Douglas D.; Minas, Taylor; Bolger, Donald J.; Booth, James R.

    2013-01-01

    Previous studies have shown that the "strength" of connectivity between regions can vary depending upon the cognitive demands of a task. In this study, the "location" of task-dependent connectivity from the primary visual cortex (V1) was examined in 43 children (ages 9-15) performing visual tasks; connectivity maxima were identified for a visual…

  10. Visualization of system dynamics using phasegrams

    PubMed Central

    Herbst, Christian T.; Herzel, Hanspeter; Švec, Jan G.; Wyman, Megan T.; Fitch, W. Tecumseh

    2013-01-01

    A new tool for visualization and analysis of system dynamics is introduced: the phasegram. Its application is illustrated with both classical nonlinear systems (logistic map and Lorenz system) and with biological voice signals. Phasegrams combine the advantages of sliding-window analysis (such as the spectrogram) with well-established visualization techniques from the domain of nonlinear dynamics. In a phasegram, time is mapped onto the x-axis, and various vibratory regimes, such as periodic oscillation, subharmonics or chaos, are identified within the generated graph by the number and stability of horizontal lines. A phasegram can be interpreted as a bifurcation diagram in time. In contrast to other analysis techniques, it can be automatically constructed from time-series data alone: no additional system parameter needs to be known. Phasegrams show great potential for signal classification and can act as the quantitative basis for further analysis of oscillating systems in many scientific fields, such as physics (particularly acoustics), biology or medicine. PMID:23697715

  11. Top-down modulation of visual and auditory cortical processing in aging.

    PubMed

    Guerreiro, Maria J S; Eck, Judith; Moerel, Michelle; Evers, Elisabeth A T; Van Gerven, Pascal W M

    2015-02-01

    Age-related cognitive decline has been accounted for by an age-related deficit in top-down attentional modulation of sensory cortical processing. In light of recent behavioral findings showing that age-related differences in selective attention are modality dependent, our goal was to investigate the role of sensory modality in age-related differences in top-down modulation of sensory cortical processing. This question was addressed by testing younger and older individuals in several memory tasks while undergoing fMRI. Throughout these tasks, perceptual features were kept constant while attentional instructions were varied, allowing us to devise all combinations of relevant and irrelevant, visual and auditory information. We found no top-down modulation of auditory sensory cortical processing in either age group. In contrast, we found top-down modulation of visual cortical processing in both age groups, and this effect did not differ between age groups. That is, older adults enhanced cortical processing of relevant visual information and suppressed cortical processing of visual distractors during auditory attention to the same extent as younger adults. The present results indicate that older adults are capable of suppressing irrelevant visual information in the context of cross-modal auditory attention, and thereby challenge the view that age-related attentional and cognitive decline is due to a general deficits in the ability to suppress irrelevant information. PMID:25300470

  12. Holodeck: Telepresence Dome Visualization System Simulations

    NASA Technical Reports Server (NTRS)

    Hite, Nicolas

    2012-01-01

    This paper explores the simulation and consideration of different image-projection strategies for the Holodeck, a dome that will be used for highly immersive telepresence operations in future endeavors of the National Aeronautics and Space Administration (NASA). Its visualization system will include a full 360 degree projection onto the dome's interior walls in order to display video streams from both simulations and recorded video. Because humans innately trust their vision to precisely report their surroundings, the Holodeck's visualization system is crucial to its realism. This system will be rigged with an integrated hardware and software infrastructure-namely, a system of projectors that will relay with a Graphics Processing Unit (GPU) and computer to both project images onto the dome and correct warping in those projections in real-time. Using both Computer-Aided Design (CAD) and ray-tracing software, virtual models of various dome/projector geometries were created and simulated via tracking and analysis of virtual light sources, leading to the selection of two possible configurations for installation. Research into image warping and the generation of dome-ready video content was also conducted, including generation of fisheye images, distortion correction, and the generation of a reliable content-generation pipeline.

  13. Desktop chaotic systems: Intuition and visualization

    NASA Technical Reports Server (NTRS)

    Bright, Michelle M.; Melcher, Kevin J.; Qammar, Helen K.; Hartley, Tom T.

    1993-01-01

    This paper presents a dynamic study of the Wildwood Pendulum, a commercially available desktop system which exhibits a strange attractor. The purpose of studying this chaotic pendulum is twofold: to gain insight in the paradigmatic approach of modeling, simulating, and determining chaos in nonlinear systems; and to provide a desktop model of chaos as a visual tool. For this study, the nonlinear behavior of this chaotic pendulum is modeled, a computer simulation is performed, and an experimental performance is measured. An assessment of the pendulum in the phase plane shows the strange attractor. Through the use of a box-assisted correlation dimension methodology, the attractor dimension is determined for both the model and the experimental pendulum systems. Correlation dimension results indicate that the pendulum and the model are chaotic and their fractal dimensions are similar.

  14. Visual Support System for Report Distinctiveness Evaluation

    NASA Astrophysics Data System (ADS)

    Sunayama, Wataru; Kawaguchi, Toshiaki

    In recent years, as the Internet has grown, electronic reports have come to be used in educational organizations such as universities. Though reports written by hand must be evaluated by hand except for stereotype descriptions or numerical answers, electronic reports can be rated by computer. There are two major criteria in rating reports, correctness and distinctiveness. Correctness is rated by absolute criteria and distinctiveness is rated by relative criteria. Relative evaluation is difficult because raters should memorize all contents of submitted reports to provide objective rates. In addition, electronic data are easily copied or exchanged by students. This paper presents a report evaluation support system with which raters can compare each report and give objective rates for distinctiveness. This system evaluates each report by objective similarity criteria and visualizes them in a two-dimensional interface as the calculated distinctiveness order. Experimental results show the system is valid and effective for estimating associations between reports.

  15. Neurotoxic actions of methylmercury on the primate visual system

    SciTech Connect

    Merigan, W.H.; Maurissen, J.P.J.; Weiss, B.; Eskin, T.; Lapham, L.W.

    1983-01-01

    Visual system consequences of exposure to methylmercury were studied in six adult, macaque monkeys. Visual field measures, visual thresholds, and morphological examination were used to determine the nature and possible reversibility of alterations in vision. Visual field constriction (especially in the inferior-nasal field) was an early and apparently reversible indicator of methylmercury intoxication. Such a field loss was found in the absence of either visual threeshold changes or morphologic alterations in visual cortex. More severe poisoning resulted in persistent field constriction, disruption of visual thresholds, and death. A single monkey showed a permanent, bilateral concentric constriction of visual fields. The locus of visual cortex pathology in this monkey corresponded to the projection of the peripheral visual field.

  16. 30 CFR 77.309 - Visual check of system equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Visual check of system equipment. 77.309 Section 77.309 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Thermal Dryers § 77.309 Visual check of system equipment. Frequent visual checks shall...

  17. 30 CFR 77.309 - Visual check of system equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Visual check of system equipment. 77.309 Section 77.309 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Thermal Dryers § 77.309 Visual check of system equipment. Frequent visual checks shall...

  18. Reduced Haemodynamic Response in the Ageing Visual Cortex Measured by Absolute fNIRS

    PubMed Central

    Ward, Laura McKernan; Aitchison, Ross Thomas; Tawse, Melisa; Simmers, Anita Jane; Shahani, Uma

    2015-01-01

    The effect of healthy ageing on visual cortical activation is still to be fully explored. This study aimed to elucidate whether the haemodynamic response (HDR) of the visual cortex altered as a result of ageing. Visually normal (healthy) participants were presented with a simple visual stimulus (reversing checkerboard). Full optometric screening was implemented to identify two age groups: younger adults (n = 12, mean age 21) and older adults (n = 13, mean age 71). Frequency-domain Multi-distance (FD-MD) functional Near-Infrared Spectroscopy (fNIRS) was used to measure absolute changes in oxygenated [HbO] and deoxygenated [HbR] haemoglobin concentrations in the occipital cortices. Utilising a slow event-related design, subjects viewed a full field reversing checkerboard with contrast and check size manipulations (15 and 30 minutes of arc, 50% and 100% contrast). Both groups showed the characteristic response of increased [HbO] and decreased [HbR] during stimulus presentation. However, older adults produced a more varied HDR and often had comparable levels of [HbO] and [HbR] during both stimulus presentation and baseline resting state. Younger adults had significantly greater concentrations of both [HbO] and [HbR] in every investigation regardless of the type of stimulus displayed (p<0.05). The average variance associated with this age-related effect for [HbO] was 88% and [HbR] 91%. Passive viewing of a visual stimulus, without any cognitive input, showed a marked age-related decline in the cortical HDR. Moreover, regardless of stimulus parameters such as check size, the HDR was characterised by age. In concurrence with present neuroimaging literature, we conclude that the visual HDR decreases as healthy ageing proceeds. PMID:25909849

  19. Visualizing the Politics of Innocence in the Age of AIDS

    ERIC Educational Resources Information Center

    Mitchell, Claudia; Walsh, Shannon; Larkin, June

    2004-01-01

    We are concerned with the ways in which social constructions of age can contribute to reducing or exacerbating the vulnerability of young people, and for this reason we refer to the issue as one of "the politics of innocence". The focus of this paper is on gender, youth and HIV prevention/AIDS awareness in the context of South Africa and…

  20. Changes in Infants' Visual Scanning across the 2- to 14-Week Age Period.

    ERIC Educational Resources Information Center

    Bronson, Gordon W.

    1990-01-01

    Longitudinal findings concerning five male and five female infants suggest a number of age-related changes in the dominant mode of visual scanning. Changes involve attention to locations of stimulus contours and prominent features of the stimulus, accuracy of saccades, and reversion to scanning behaviors typical of younger ages under certain…

  1. Age Differences in Visual Working Memory Capacity: Not Based on Encoding Limitations

    ERIC Educational Resources Information Center

    Cowan, Nelson; AuBuchon, Angela M.; Gilchrist, Amanda L.; Ricker, Timothy J.; Saults, J. Scott

    2011-01-01

    Why does visual working memory performance increase with age in childhood? One recent study (Cowan et al., 2010b) ruled out the possibility that the basic cause is a tendency in young children to clutter working memory with less-relevant items (within a concurrent array, colored items presented in one of two shapes). The age differences in memory…

  2. Age Effects in the Use of Sentence Context in Visual Word Recognition.

    ERIC Educational Resources Information Center

    Madden, David J.

    Age-related deficits may exist in episodic memory (knowledge of the context in which an item appeared previously) and semantic memory (knowledge of an item's meaning independent of the context). In order to examine adult age differences in semantic priming effects and subsequent episodic retention for visually presented words, 24 young (18-22…

  3. Visual Turing test for computer vision systems.

    PubMed

    Geman, Donald; Geman, Stuart; Hallonquist, Neil; Younes, Laurent

    2015-03-24

    Today, computer vision systems are tested by their accuracy in detecting and localizing instances of objects. As an alternative, and motivated by the ability of humans to provide far richer descriptions and even tell a story about an image, we construct a "visual Turing test": an operator-assisted device that produces a stochastic sequence of binary questions from a given test image. The query engine proposes a question; the operator either provides the correct answer or rejects the question as ambiguous; the engine proposes the next question ("just-in-time truthing"). The test is then administered to the computer-vision system, one question at a time. After the system's answer is recorded, the system is provided the correct answer and the next question. Parsing is trivial and deterministic; the system being tested requires no natural language processing. The query engine employs statistical constraints, learned from a training set, to produce questions with essentially unpredictable answers-the answer to a question, given the history of questions and their correct answers, is nearly equally likely to be positive or negative. In this sense, the test is only about vision. The system is designed to produce streams of questions that follow natural story lines, from the instantiation of a unique object, through an exploration of its properties, and on to its relationships with other uniquely instantiated objects. PMID:25755262

  4. Effects of age, gender, and stimulus presentation period on visual short-term memory.

    PubMed

    Kunimi, Mitsunobu

    2016-01-01

    This study focused on age-related changes in visual short-term memory using visual stimuli that did not allow verbal encoding. Experiment 1 examined the effects of age and the length of the stimulus presentation period on visual short-term memory function. Experiment 2 examined the effects of age, gender, and the length of the stimulus presentation period on visual short-term memory function. The worst memory performance and the largest performance difference between the age groups were observed in the shortest stimulus presentation period conditions. The performance difference between the age groups became smaller as the stimulus presentation period became longer; however, it did not completely disappear. Although gender did not have a significant effect on d' regardless of the presentation period in the young group, a significant gender-based difference was observed for stimulus presentation periods of 500 ms and 1,000 ms in the older group. This study indicates that the decline in visual short-term memory observed in the older group is due to the interaction of several factors. PMID:26745456

  5. Visual Turing test for computer vision systems

    PubMed Central

    Geman, Donald; Geman, Stuart; Hallonquist, Neil; Younes, Laurent

    2015-01-01

    Today, computer vision systems are tested by their accuracy in detecting and localizing instances of objects. As an alternative, and motivated by the ability of humans to provide far richer descriptions and even tell a story about an image, we construct a “visual Turing test”: an operator-assisted device that produces a stochastic sequence of binary questions from a given test image. The query engine proposes a question; the operator either provides the correct answer or rejects the question as ambiguous; the engine proposes the next question (“just-in-time truthing”). The test is then administered to the computer-vision system, one question at a time. After the system’s answer is recorded, the system is provided the correct answer and the next question. Parsing is trivial and deterministic; the system being tested requires no natural language processing. The query engine employs statistical constraints, learned from a training set, to produce questions with essentially unpredictable answers—the answer to a question, given the history of questions and their correct answers, is nearly equally likely to be positive or negative. In this sense, the test is only about vision. The system is designed to produce streams of questions that follow natural story lines, from the instantiation of a unique object, through an exploration of its properties, and on to its relationships with other uniquely instantiated objects. PMID:25755262

  6. Divergent Trajectories in the Aging Mind: Changes in Working Memory for Affective Versus Visual Information With Age

    PubMed Central

    Mikels, Joseph A.; Larkin, Gregory R.; Reuter-Lorenz, Patricia A.; Carstensen, Laura L.

    2009-01-01

    Working memory mediates the short-term maintenance of information. Virtually all empirical research on working memory involves investigations of working memory for verbal and visual information. Whereas aging is typically associated with a deficit in working memory for these types of information, recent findings suggestive of relatively well-preserved long-term memory for emotional information in older adults raise questions about working memory for emotional material. This study examined age differences in working memory for emotional versus visual information. Findings demonstrate that, despite an age-related deficit for the latter, working memory for emotion was unimpaired. Further, older adults exhibited superior performance on positive relative to negative emotion trials, whereas their younger counterparts exhibited the opposite pattern. PMID:16420130

  7. Age-related changes in visual exploratory behavior in a natural scene setting

    PubMed Central

    Hamel, Johanna; De Beukelaer, Sophie; Kraft, Antje; Ohl, Sven; Audebert, Heinrich J.; Brandt, Stephan A.

    2013-01-01

    Diverse cognitive functions decline with increasing age, including the ability to process central and peripheral visual information in a laboratory testing situation (useful visual field of view). To investigate whether and how this influences activities of daily life, we studied age-related changes in visual exploratory behavior in a natural scene setting: a driving simulator paradigm of variable complexity was tested in subjects of varying ages with simultaneous eye- and head-movement recordings via a head-mounted camera. Detection and reaction times were also measured by visual fixation and manual reaction. We considered video computer game experience as a possible influence on performance. Data of 73 participants of varying ages were analyzed, driving two different courses. We analyzed the influence of route difficulty level, age, and eccentricity of test stimuli on oculomotor and driving behavior parameters. No significant age effects were found regarding saccadic parameters. In the older subjects head-movements increasingly contributed to gaze amplitude. More demanding courses and more peripheral stimuli locations induced longer reaction times in all age groups. Deterioration of the functionally useful visual field of view with increasing age was not suggested in our study group. However, video game-experienced subjects revealed larger saccade amplitudes and a broader distribution of fixations on the screen. They reacted faster to peripheral objects suggesting the notion of a general detection task rather than perceiving driving as a central task. As the video game-experienced population consisted of younger subjects, our study indicates that effects due to video game experience can easily be misinterpreted as age effects if not accounted for. We therefore view it as essential to consider video game experience in all testing methods using virtual media. PMID:23801970

  8. Monterey Learning Systems: Improving Academic Achievement of Visually Impaired Learners

    ERIC Educational Resources Information Center

    Daugherty, Kathryn M.

    1977-01-01

    Tested was the premise that the academic competencies of visually impaired learners could be enhanced by training procedures that combine auditory and visual skills in a project using the Monterey Learning Systems Reading and Mathematics Programs with 29 visually impaired print readers. (Author/MH)

  9. Computer Visual System (CVS) reference manual

    SciTech Connect

    Snider, D.M.; Wagner, K.L.

    1985-01-01

    This is a reference manual for the Idaho National Engineering Laboratory (INEL) Computer Visual System (CVS). The manual contains a summary of the operation of the CVS program and describes the hardware requirements. It explains the main features and operation of the program as well as how to communicate with the host computer. CVS is a high performance color graphics system. This system enables color pictures to be generated and edited on a color raster terminal and subsequently output as 35mm color transparencies and gray-scale or black and white hard copies. CVS provides processors for the construction of word slides, tables, charts, and sketches. Commands for the creation and editing of images are entered by picking items from menus displayed on the terminal screen. The CVS program executes on a Control Data Corporation (CDC) CYBER 176 computer under the NOS operating system. The user interacts with CVS through a terminal, entering commands from a keyboard and tablet. Currently, only the Advanced Electronic Design (AED) line of color terminals are supported for graphic input to CVS. As other terminals become available, modules to drive these terminals will be included.

  10. Aging changes in the female reproductive system

    MedlinePlus

    ... ency/article/004016.htm Aging changes in the female reproductive system To use the sharing features on this page, please enable JavaScript. Aging changes in the female reproductive system result mainly from changing hormone levels . One clear ...

  11. Age-related sensitive periods influence visual language discrimination in adults.

    PubMed

    Weikum, Whitney M; Vouloumanos, Athena; Navarra, Jordi; Soto-Faraco, Salvador; Sebastián-Gallés, Núria; Werker, Janet F

    2013-01-01

    Adults as well as infants have the capacity to discriminate languages based on visual speech alone. Here, we investigated whether adults' ability to discriminate languages based on visual speech cues is influenced by the age of language acquisition. Adult participants who had all learned English (as a first or second language) but did not speak French were shown faces of bilingual (French/English) speakers silently reciting sentences in either language. Using only visual speech information, adults who had learned English from birth or as a second language before the age of 6 could discriminate between French and English significantly better than chance. However, adults who had learned English as a second language after age 6 failed to discriminate these two languages, suggesting that early childhood exposure is crucial for using relevant visual speech information to separate languages visually. These findings raise the possibility that lowered sensitivity to non-native visual speech cues may contribute to the difficulties encountered when learning a new language in adulthood. PMID:24312020

  12. Age-related sensitive periods influence visual language discrimination in adults

    PubMed Central

    Weikum, Whitney M.; Vouloumanos, Athena; Navarra, Jordi; Soto-Faraco, Salvador; Sebastián-Gallés, Núria; Werker, Janet F.

    2013-01-01

    Adults as well as infants have the capacity to discriminate languages based on visual speech alone. Here, we investigated whether adults' ability to discriminate languages based on visual speech cues is influenced by the age of language acquisition. Adult participants who had all learned English (as a first or second language) but did not speak French were shown faces of bilingual (French/English) speakers silently reciting sentences in either language. Using only visual speech information, adults who had learned English from birth or as a second language before the age of 6 could discriminate between French and English significantly better than chance. However, adults who had learned English as a second language after age 6 failed to discriminate these two languages, suggesting that early childhood exposure is crucial for using relevant visual speech information to separate languages visually. These findings raise the possibility that lowered sensitivity to non-native visual speech cues may contribute to the difficulties encountered when learning a new language in adulthood. PMID:24312020

  13. Task- and age-dependent effects of visual stimulus properties on children's explicit numerosity judgments.

    PubMed

    Defever, Emmy; Reynvoet, Bert; Gebuis, Titia

    2013-10-01

    Researchers investigating numerosity processing manipulate the visual stimulus properties (e.g., surface). This is done to control for the confound between numerosity and its visual properties and should allow the examination of pure number processes. Nevertheless, several studies have shown that, despite different visual controls, visual cues remained to exert their influence on numerosity judgments. This study, therefore, investigated whether the impact of the visual stimulus manipulations on numerosity judgments is dependent on the task at hand (comparison task vs. same-different task) and whether this impact changes throughout development. In addition, we examined whether the influence of visual stimulus manipulations on numerosity judgments plays a role in the relation between performance on numerosity tasks and mathematics achievement. Our findings confirmed that the visual stimulus manipulations affect numerosity judgments; more important, we found that these influences changed with increasing age and differed between the comparison and the same-different tasks. Consequently, direct comparisons between numerosity studies using different tasks and age groups are difficult. No meaningful relationship between the performance on the comparison and same-different tasks and mathematics achievement was found in typically developing children, nor did we find consistent differences between children with and without mathematical learning disability (MLD). PMID:23860419

  14. Age-related decline of precision and binding in visual working memory.

    PubMed

    Peich, Muy-Cheng; Husain, Masud; Bays, Paul M

    2013-09-01

    Working memory declines with normal aging, but the nature of this impairment is debated. Studies based on detecting changes to arrays of visual objects have identified two possible components to age-related decline: a reduction in the number of items that can be stored, or a deficit in maintaining the associations (bindings) between individual object features. However, some investigations have reported intact binding with aging, and specific deficits arising only in Alzheimer's disease. Here, using a recently developed continuous measure of recall fidelity, we tested the precision with which adults of different ages could reproduce from memory the orientation and color of a probed array item. The results reveal a further component of cognitive decline: an age-related decrease in the resolution with which visual information can be maintained in working memory. This increase in recall variability with age was strongest under conditions of greater memory load. Moreover, analysis of the distribution of errors revealed that older participants were more likely to incorrectly report one of the unprobed items in memory, consistent with an age-related increase in misbinding. These results indicate a systematic decline with age in working memory resources that can be recruited to store visual information. The paradigm presented here provides a sensitive index of both memory resolution and feature binding, with the potential for assessing their modulation by interventions. The findings have implications for understanding the mechanisms underpinning working memory deficits in both health and disease. PMID:23978008

  15. Orbitofrontal Cortex and the Early Processing of Visual Novelty in Healthy Aging

    PubMed Central

    Kaufman, David A. S.; Keith, Cierra M.; Perlstein, William M.

    2016-01-01

    Event-related potential (ERP) studies have previously found that scalp topographies of attention-related ERP components show frontal shifts with age, suggesting an increased need for compensatory frontal activity to assist with top-down facilitation of attention. However, the precise neural time course of top-down attentional control in aging is not clear. In this study, 20 young (mean: 22 years) and 14 older (mean: 64 years) adults completed a three-stimulus visual oddball task while high-density ERPs were acquired. Colorful, novel distracters were presented to engage early visual processing. Relative to young controls, older participants exhibited elevations in occipital early posterior positivity (EPP), approximately 100 ms after viewing colorful distracters. Neural source models for older adults implicated unique patterns of orbitofrontal cortex (OFC; BA 11) activity during early visual novelty processing (100 ms), which was positively correlated with subsequent activations in primary visual cortex (BA 17). Older adult EPP amplitudes and OFC activity were associated with performance on tests of complex attention and executive function. These findings are suggestive of age-related, compensatory neural changes that may driven by a combination of weaker cortical efficiency and increased need for top-down control over attention. Accordingly, enhanced early OFC activity during visual attention may serve as an important indicator of frontal lobe integrity in healthy aging. PMID:27199744

  16. Orbitofrontal Cortex and the Early Processing of Visual Novelty in Healthy Aging.

    PubMed

    Kaufman, David A S; Keith, Cierra M; Perlstein, William M

    2016-01-01

    Event-related potential (ERP) studies have previously found that scalp topographies of attention-related ERP components show frontal shifts with age, suggesting an increased need for compensatory frontal activity to assist with top-down facilitation of attention. However, the precise neural time course of top-down attentional control in aging is not clear. In this study, 20 young (mean: 22 years) and 14 older (mean: 64 years) adults completed a three-stimulus visual oddball task while high-density ERPs were acquired. Colorful, novel distracters were presented to engage early visual processing. Relative to young controls, older participants exhibited elevations in occipital early posterior positivity (EPP), approximately 100 ms after viewing colorful distracters. Neural source models for older adults implicated unique patterns of orbitofrontal cortex (OFC; BA 11) activity during early visual novelty processing (100 ms), which was positively correlated with subsequent activations in primary visual cortex (BA 17). Older adult EPP amplitudes and OFC activity were associated with performance on tests of complex attention and executive function. These findings are suggestive of age-related, compensatory neural changes that may driven by a combination of weaker cortical efficiency and increased need for top-down control over attention. Accordingly, enhanced early OFC activity during visual attention may serve as an important indicator of frontal lobe integrity in healthy aging. PMID:27199744

  17. A Visualization System for Interactive Exploration of the Cardiac Anatomy.

    PubMed

    Zhang, Lei; Wang, Kuanquan; Yang, Fei; Lu, Wenjing; Wang, Kechao; Zhang, Yue; Liang, Xiaoqing; Han, Dongchen; Zhu, Ying Julie

    2016-06-01

    Because of the complex and fine structure, visualization of the heart still remains a challenging task, which makes it an active research topic. In this paper, we present a visualization system for medical data, which takes advantage of the recent graphics processing unit (GPU) and can provide real-time cardiac visualization. This work focuses on investigating the anatomical structure visualization of the human heart, which is fundamental to the cardiac visualization, medical training and diagnosis assistance. Several state-of-the-art cardiac visualization methods are integrated into the proposed system and a task specified visualization method is proposed. In addition, auxiliary tools are provided to generate user specified visualization results. The contributions of our work lie in two-fold: for doctors and medical staff, the system can provide task specified visualization with interactive visualization tools; for researchers, the proposed platform can serve as a baseline for comparing different rendering methods and can easily incorporate new rendering methods. Experimental results show that the proposed system can provide favorable cardiac visualization results in terms of both effectiveness and efficiency. PMID:27098778

  18. Preserving visual saliency in image to sound substitution systems

    NASA Astrophysics Data System (ADS)

    Ancuti, Codruta O.; Ancuti, Cosmin; Bekaert, Philippe

    2009-02-01

    Color plays a significant role in the scene interpretation in terms of visual perception. Numerous visual substitution systems deal with grayscale images disregarding this information from original image. Visually percept color-based details often fade due to the grayscale conversion and that can mislead the overall comprehension of the considered scene. We present a decolorization method that considers color contrast and preserve color saliency after transformation. We exploit this model to enhance the perception of visually disable persons over the interpreted images by the substitution system. The results demonstrate that our enhance system is capable to improves the overall scene interpretation in comparison with similar substitution system.

  19. Auditory and Visual Continuous Performance Tests: Relationships with Age, Gender, Cognitive Functioning, and Classroom Behavior

    ERIC Educational Resources Information Center

    Lehman, Elyse Brauch; Olson, Vanessa A.; Aquilino, Sally A.; Hall, Laura C.

    2006-01-01

    Elementary school children in three grade groups (Grades K/1, 3, and 5/6) completed either the auditory or the visual 1/9 vigilance task from the Gordon Diagnostic System (GDS) as well as subtests from the Wechsler Intelligence Scale for Children--Third Edition and auditory or visual processing subtests from the Woodcock-Johnson Tests of Cognitive…

  20. 40 CFR 202.22 - Visual exhaust system inspection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Visual exhaust system inspection. 202... Standards § 202.22 Visual exhaust system inspection. No motor carrier subject to these regulations shall operate any motor vehicle of a type to which this regulation is applicable unless the exhaust system...

  1. Visual Development and Neuropsychological Profile in Preterm Children from 6 Months to School Age.

    PubMed

    Sayeur, Mélissa Sue; Vannasing, Phetsamone; Tremblay, Emmanuel; Lepore, Franco; McKerral, Michelle; Lassonde, Maryse; Gallagher, Anne

    2015-08-01

    The aim of this semilongitudinal study was to investigate the development of central visual pathways in children born preterm but without major neurologic impairments and to establish their cognitive and behavioral profile at school age. Ten children born preterm were assessed at 6 months and at school age, using visual evoked potentials at both time points and cognitive and behavioral tests at school age. We also tested 10 age-matched children born full-term. At 6 months' corrected age, we found no significant differences between preterm and full-term groups for either amplitude or latency of N1 and P1 components. At school age, the preterm group manifested significantly higher N1 amplitudes and tended to show higher P1 amplitudes than the full-term group. We found no significant differences in cognitive and behavioral measures at school age. These results suggest that preterm birth affects visual pathways development, yet the children born preterm did not manifest cognitive problems. PMID:25414236

  2. Development of the visually impaired person guidance system using GPS.

    PubMed

    Soeda, Koji; Aoki, Shingo; Yanashima, Kenji; Magatani, Kazushige

    2004-01-01

    Most of the visually impaired are able to walk independently, if they have the mental map of their walking area. However, in their unknown area, they cannot walk alone and they need a guide dog or help of others for walking. And not only a supporter of the visually impaired but a visually impaired person receives stress while walking. More over in Japan, there are about 300,000 visually impaired persons, and are about 900 guide dogs. These number of guide dogs are too few. Therefore, an auto navigation system for the visually impaired is required in Japan. Our objective is the development of the auto navigation system for the visually impaired. This navigation system obtains the position of an user (visually impaired user) by DGPS. From the digital map data base in our system and the position of an use are analyzed, and suitable route to the destination is calculated, and then our system guides the way to the destination to the user. In this paper, we'd like to report about our new navigation system for the visually impaired and report some experimental results of our system. From these results, we think our system will be a powerful for the visually impaired. PMID:17271403

  3. Visual Awareness Is Limited by the Representational Architecture of the Visual System.

    PubMed

    Cohen, Michael A; Nakayama, Ken; Konkle, Talia; Stantić, Mirta; Alvarez, George A

    2015-11-01

    Visual perception and awareness have strict limitations. We suggest that one source of these limitations is the representational architecture of the visual system. Under this view, the extent to which items activate the same neural channels constrains the amount of information that can be processed by the visual system and ultimately reach awareness. Here, we measured how well stimuli from different categories (e.g., faces and cars) blocked one another from reaching awareness using two distinct paradigms that render stimuli invisible: visual masking and continuous flash suppression. Next, we used fMRI to measure the similarity of the neural responses elicited by these categories across the entire visual hierarchy. Overall, we found strong brain-behavior correlations within the ventral pathway, weaker correlations in the dorsal pathway, and no correlations in early visual cortex (V1-V3). These results suggest that the organization of higher level visual cortex constrains visual awareness and the overall processing capacity of visual cognition. PMID:26226078

  4. Computer systems and methods for visualizing data

    DOEpatents

    Stolte, Chris; Hanrahan, Patrick

    2010-07-13

    A method for forming a visual plot using a hierarchical structure of a dataset. The dataset comprises a measure and a dimension. The dimension consists of a plurality of levels. The plurality of levels form a dimension hierarchy. The visual plot is constructed based on a specification. A first level from the plurality of levels is represented by a first component of the visual plot. A second level from the plurality of levels is represented by a second component of the visual plot. The dataset is queried to retrieve data in accordance with the specification. The data includes all or a portion of the dimension and all or a portion of the measure. The visual plot is populated with the retrieved data in accordance with the specification.

  5. Motor Skill Performance of School-Age Children with Visual Impairments

    ERIC Educational Resources Information Center

    Houwen, S.; Visscher, C.; Lemmink, K. A. P. M.; Hartman, E.

    2008-01-01

    The aim of this study was to examine the performance of children with visual impairments (VI) aged 7 to 10 years on different types of motor skills. Furthermore, the association between the degree of the VI and motor performance was examined. The motor performance of 48 children with VI (32 males, 16 females; mean age 8y 10mo [SD 1y 1mo]) was…

  6. A knowledge based system for scientific data visualization

    NASA Technical Reports Server (NTRS)

    Senay, Hikmet; Ignatius, Eve

    1992-01-01

    A knowledge-based system, called visualization tool assistant (VISTA), which was developed to assist scientists in the design of scientific data visualization techniques, is described. The system derives its knowledge from several sources which provide information about data characteristics, visualization primitives, and effective visual perception. The design methodology employed by the system is based on a sequence of transformations which decomposes a data set into a set of data partitions, maps this set of partitions to visualization primitives, and combines these primitives into a composite visualization technique design. Although the primary function of the system is to generate an effective visualization technique design for a given data set by using principles of visual perception the system also allows users to interactively modify the design, and renders the resulting image using a variety of rendering algorithms. The current version of the system primarily supports visualization techniques having applicability in earth and space sciences, although it may easily be extended to include other techniques useful in other disciplines such as computational fluid dynamics, finite-element analysis and medical imaging.

  7. Age-related slowing of response selection and production in a visual choice reaction time task.

    PubMed

    Woods, David L; Wyma, John M; Yund, E William; Herron, Timothy J; Reed, Bruce

    2015-01-01

    Aging is associated with delayed processing in choice reaction time (CRT) tasks, but the processing stages most impacted by aging have not been clearly identified. Here, we analyzed CRT latencies in a computerized serial visual feature-conjunction task. Participants responded to a target letter (probability 40%) by pressing one mouse button, and responded to distractor letters differing either in color, shape, or both features from the target (probabilities 20% each) by pressing the other mouse button. Stimuli were presented randomly to the left and right visual fields and stimulus onset asynchronies (SOAs) were adaptively reduced following correct responses using a staircase procedure. In Experiment 1, we tested 1466 participants who ranged in age from 18 to 65 years. CRT latencies increased significantly with age (r = 0.47, 2.80 ms/year). Central processing time (CPT), isolated by subtracting simple reaction times (SRT) (obtained in a companion experiment performed on the same day) from CRT latencies, accounted for more than 80% of age-related CRT slowing, with most of the remaining increase in latency due to slowed motor responses. Participants were faster and more accurate when the stimulus location was spatially compatible with the mouse button used for responding, and this effect increased slightly with age. Participants took longer to respond to distractors with target color or shape than to distractors with no target features. However, the additional time needed to discriminate the more target-like distractors did not increase with age. In Experiment 2, we replicated the findings of Experiment 1 in a second population of 178 participants (ages 18-82 years). CRT latencies did not differ significantly in the two experiments, and similar effects of age, distractor similarity, and stimulus-response spatial compatibility were found. The results suggest that the age-related slowing in visual CRT latencies is largely due to delays in response selection and

  8. Age-related slowing of response selection and production in a visual choice reaction time task

    PubMed Central

    Woods, David L.; Wyma, John M.; Yund, E. William; Herron, Timothy J.; Reed, Bruce

    2015-01-01

    Aging is associated with delayed processing in choice reaction time (CRT) tasks, but the processing stages most impacted by aging have not been clearly identified. Here, we analyzed CRT latencies in a computerized serial visual feature-conjunction task. Participants responded to a target letter (probability 40%) by pressing one mouse button, and responded to distractor letters differing either in color, shape, or both features from the target (probabilities 20% each) by pressing the other mouse button. Stimuli were presented randomly to the left and right visual fields and stimulus onset asynchronies (SOAs) were adaptively reduced following correct responses using a staircase procedure. In Experiment 1, we tested 1466 participants who ranged in age from 18 to 65 years. CRT latencies increased significantly with age (r = 0.47, 2.80 ms/year). Central processing time (CPT), isolated by subtracting simple reaction times (SRT) (obtained in a companion experiment performed on the same day) from CRT latencies, accounted for more than 80% of age-related CRT slowing, with most of the remaining increase in latency due to slowed motor responses. Participants were faster and more accurate when the stimulus location was spatially compatible with the mouse button used for responding, and this effect increased slightly with age. Participants took longer to respond to distractors with target color or shape than to distractors with no target features. However, the additional time needed to discriminate the more target-like distractors did not increase with age. In Experiment 2, we replicated the findings of Experiment 1 in a second population of 178 participants (ages 18–82 years). CRT latencies did not differ significantly in the two experiments, and similar effects of age, distractor similarity, and stimulus-response spatial compatibility were found. The results suggest that the age-related slowing in visual CRT latencies is largely due to delays in response selection and

  9. Aging of non-visual spectral sensitivity to light in humans: compensatory mechanisms?

    PubMed

    Najjar, Raymond P; Chiquet, Christophe; Teikari, Petteri; Cornut, Pierre-Loïc; Claustrat, Bruno; Denis, Philippe; Cooper, Howard M; Gronfier, Claude

    2014-01-01

    The deterioration of sleep in the older population is a prevalent feature that contributes to a decrease in quality of life. Inappropriate entrainment of the circadian clock by light is considered to contribute to the alteration of sleep structure and circadian rhythms in the elderly. The present study investigates the effects of aging on non-visual spectral sensitivity to light and tests the hypothesis that circadian disturbances are related to a decreased light transmittance. In a within-subject design, eight aged and five young subjects were exposed at night to 60 minute monochromatic light stimulations at 9 different wavelengths (420-620 nm). Individual sensitivity spectra were derived from measures of melatonin suppression. Lens density was assessed using a validated psychophysical technique. Although lens transmittance was decreased for short wavelength light in the older participants, melatonin suppression was not reduced. Peak of non-visual sensitivity was, however, shifted to longer wavelengths in the aged participants (494 nm) compared to young (484 nm). Our results indicate that increased lens filtering does not necessarily lead to a decreased non-visual sensitivity to light. The lack of age-related decrease in non-visual sensitivity to light may involve as yet undefined adaptive mechanisms. PMID:24465738

  10. Self-Perceptions of Visually Impaired Children Aged 3-10 in India.

    ERIC Educational Resources Information Center

    Christy, Beula; Shanimole; Nuthetie, Rishita

    2002-01-01

    A study analyzed the self-perceptions of 50 Indian children (ages 3-10) with visual impairments in their expressions of mood and feelings, needs and wants, and preferences and decision making. Children had difficulty expressing sympathy, particularly younger children. Children also difficulty choosing what they wanted to wear. (Contains 7…

  11. Reliability and Validity of the TGMD-2 in Primary-School-Age Children with Visual Impairments

    ERIC Educational Resources Information Center

    Houwen, Suzanne; Hartman, Esther; Jonker, Laura; Visscher, Chris

    2010-01-01

    This study examines the psychometric properties of the Test of Gross Motor Development-2 (TGMD-2) in children with visual impairments (VI). Seventy-five children aged between 6 and 12 years with VI completed the TGMD-2 and the Movement Assessment Battery for Children (Movement ABC). The internal consistency of the TGMD-2 was found to be high…

  12. Factors Affecting the Successful Employment of Transition-Age Youths with Visual Impairments

    ERIC Educational Resources Information Center

    McDonnall, Michele Capella; Crudden, Adele

    2009-01-01

    The following variables were found to be associated with employment for transition-age youths with visual impairments who are served by vocational rehabilitation agencies: work experience, academic competence, self-determination, use of assistive technology, and locus of control. Self-esteem and involvement with the counselor were not associated…

  13. The Employment and Postsecondary Educational Status of Transition-Age Youths with Visual Impairments

    ERIC Educational Resources Information Center

    McDonnall, Michele Capella

    2010-01-01

    A limited amount of information is available about the employment and postsecondary educational status of transition-age youths with visual impairments. Reports on the employment and postsecondary education tend to focus on overall results and usually do not provide detailed analyses by disability groups. In this article, the author presents the…

  14. Rapid Resumption of Interrupted Search Is Independent of Age-Related Improvements in Visual Search

    ERIC Educational Resources Information Center

    Lleras, Alejandro; Porporino, Mafalda; Burack, Jacob A.; Enns, James T.

    2011-01-01

    In this study, 7-19-year-olds performed an interrupted visual search task in two experiments. Our question was whether the tendency to respond within 500 ms after a second glimpse of a display (the "rapid resumption" effect ["Psychological Science", 16 (2005) 684-688]) would increase with age in the same way as overall search efficiency. The…

  15. Age-Related Visual Changes and Their Impications for the Motor Skill Performance of Older Adults.

    ERIC Educational Resources Information Center

    Haywood, Kathleen M.; Trick, Linda R.

    Physical changes in and conditions of the eye associated with the normal aging process are discussed with reference to their impact on performance in physical and recreational activities. Descriptions are given of characteristic changes in visual acuity in the areas of: (1) presbyopia (inability to clearly focus near images); (2) sensitivity to…

  16. Aging of Non-Visual Spectral Sensitivity to Light in Humans: Compensatory Mechanisms?

    PubMed Central

    Najjar, Raymond P.; Chiquet, Christophe; Teikari, Petteri; Cornut, Pierre-Loïc; Claustrat, Bruno; Denis, Philippe; Gronfier, Claude

    2014-01-01

    The deterioration of sleep in the older population is a prevalent feature that contributes to a decrease in quality of life. Inappropriate entrainment of the circadian clock by light is considered to contribute to the alteration of sleep structure and circadian rhythms in the elderly. The present study investigates the effects of aging on non-visual spectral sensitivity to light and tests the hypothesis that circadian disturbances are related to a decreased light transmittance. In a within-subject design, eight aged and five young subjects were exposed at night to 60 minute monochromatic light stimulations at 9 different wavelengths (420–620 nm). Individual sensitivity spectra were derived from measures of melatonin suppression. Lens density was assessed using a validated psychophysical technique. Although lens transmittance was decreased for short wavelength light in the older participants, melatonin suppression was not reduced. Peak of non-visual sensitivity was, however, shifted to longer wavelengths in the aged participants (494 nm) compared to young (484 nm). Our results indicate that increased lens filtering does not necessarily lead to a decreased non-visual sensitivity to light. The lack of age-related decrease in non-visual sensitivity to light may involve as yet undefined adaptive mechanisms. PMID:24465738

  17. Age-of-Acquisition Effects in Visual Word Recognition: Evidence from Expert Vocabularies

    ERIC Educational Resources Information Center

    Stadthagen-Gonzalez, Hans; Bowers, Jeffrey S.; Damian, Markus F.

    2004-01-01

    Three experiments assessed the contributions of age-of-acquisition (AoA) and frequency to visual word recognition. Three databases were created from electronic journals in chemistry, psychology and geology in order to identify technical words that are extremely frequent in each discipline but acquired late in life. In Experiment 1, psychologists…

  18. Stress Constellations and Coping Styles of Older Adults with Age-Related Visual Impairment

    ERIC Educational Resources Information Center

    Lee, Kyoung Othelia; Brennan, Mark

    2006-01-01

    Narrative data from two earlier studies of adaptation to age-related visual impairment were examined for constellations of stressors and coping styles. In the course of previous qualitative analyses, the researchers identified stress and coping codes according to behavioral, psychological, and social domains using a grounded theory approach. In…

  19. Effective maintenance practices to manage system aging

    NASA Astrophysics Data System (ADS)

    Chockie, Alan; Bjorkelo, Kenneth

    A study for the Nuclear Regulatory Commission was recently undertaken to identify effective maintenance practices that could be adapted by the nuclear industry in the United States to assist in managing the aging degradation of plant systems and components. Four organizations were examined to assess the influence of maintenance programs on addressing the system and component aging degradation issues. An effective maintenance program was found to be essential to the management of system and component aging. Four key elements of an effective maintenance program that are important to an aging management were identified: (1) the selection of critical systems and components; (2) the development of an understanding of aging through the collection and analysis of equipment performance information; (3) the development of appropriate preventive and predictive maintenance tasks to manage equipment and system aging degradation; and (4) the use of feedback mechanisms to continuously improve the management of aging systems and components. These elements were found to be common to all four organizations.

  20. TOPICAL REVIEW: Prosthetic interfaces with the visual system: biological issues

    NASA Astrophysics Data System (ADS)

    Cohen, Ethan D.

    2007-06-01

    The design of effective visual prostheses for the blind represents a challenge for biomedical engineers and neuroscientists. Significant progress has been made in the miniaturization and processing power of prosthesis electronics; however development lags in the design and construction of effective machine brain interfaces with visual system neurons. This review summarizes what has been learned about stimulating neurons in the human and primate retina, lateral geniculate nucleus and visual cortex. Each level of the visual system presents unique challenges for neural interface design. Blind patients with the retinal degenerative disease retinitis pigmentosa (RP) are a common population in clinical trials of visual prostheses. The visual performance abilities of normals and RP patients are compared. To generate pattern vision in blind patients, the visual prosthetic interface must effectively stimulate the retinotopically organized neurons in the central visual field to elicit patterned visual percepts. The development of more biologically compatible methods of stimulating visual system neurons is critical to the development of finer spatial percepts. Prosthesis electrode arrays need to adapt to different optimal stimulus locations, stimulus patterns, and patient disease states.

  1. Long-term Effects of Prenatal Omega-3 Fatty Acid Intake on Visual Function in School-Age Children

    PubMed Central

    Jacques, Caroline; Levy, Emile; Muckle, Gina; Jacobson, Sandra W.; Bastien, Célyne; Dewailly, Éric; Ayotte, Pierre; Jacobson, Joseph L.; Saint-Amour, Dave

    2010-01-01

    Objective To assess the long-term effect of omega-3 polyunsaturated fatty acids (n-3 PUFA) intake during gestation on visual development. Study design We examined the long-term effects in 136 school-age Inuit children exposed to high levels of n-3 PUFAs during gestation using visual evoked potentials (VEPs). VEP protocols using color and motion stimuli were used to assess parvo- and magnocellular responses. Concentrations of the two major n-3 PUFAs (DHA and EPA) were measured in umbilical cord and child plasma phospholipids, reflecting pre- and postnatal exposure, respectively. Results After adjustment for confounders, cord plasma DHA was associated with shorter latencies of the N1 and P1 components of the color VEPs. No effects were found for current n-3 PUFA body burden or motion-onset VEPs. Conclusion This study demonstrates beneficial effects of DHA intake during gestation on visual system function at school age. DHA is particularly important for the early development and long-term function of the visual parvocellular pathway. PMID:20797725

  2. Development of the Visual System and Implications for Early Intervention.

    ERIC Educational Resources Information Center

    Glass, Penny

    2002-01-01

    This article summarizes the early development of the visual system within the context of the other sensory systems and preterm birth and relates this information to early intervention. Retinopathy of prematurely, ocular defects, cortical visual impairment and potential impact of the neonatal intensive care unit environment are discussed. (Contains…

  3. 40 CFR 202.22 - Visual exhaust system inspection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Visual exhaust system inspection. 202.22 Section 202.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE... Standards § 202.22 Visual exhaust system inspection. No motor carrier subject to these regulations...

  4. The Response to Visual Form Deprivation Differs with Age in Marmosets

    PubMed Central

    Troilo, David; Nickla, Debora L.

    2007-01-01

    Purpose To characterize the effects of visual form deprivation by diffuser in marmoset monkey eyes across a range of ages. Methods Twenty-four common marmosets were grouped by onset of deprivation (group 1: 0-39 days, n = 6; group 2: 40-99 days, n = 10; and group 3: 100-200 days, n = 8). Monocular form deprivation was induced with a white translucent diffuser worn for 28 to 88 days (mean durations: group 1, 32 days; group 2, 56 days; and group 3, 51 days). Refractive state, corneal curvature, and vitreous chamber depth were measured after cycloplegia. Both experimental and control eyes were measured multiple times before, during, and after the visual deprivation period. Results Marmosets in all age groups tested were susceptible to visual form deprivation myopia; however, the response to form deprivation was variable and included a majority with axial myopia (n = 15), several nonresponders (n = 4), a single late responder (axial myopia after the end of deprivation period), and several axial hyperopes (n = 4). For all animals that responded with axial myopia, the increase in vitreous chamber depth and myopia was inversely proportional to the age of onset of deprivation (ANOVA, P < 0.05). After the end of the period of deprivation, recovery from myopia by reduction of the axial growth rate was observed in three animals from group 1 and three animals from group 2. Conclusions Form deprivation by diffusers disrupted emmetropization in marmosets over a range of ages. The responses varied among individuals and with age, suggesting that the maturity of the eye may influence the response to visual signals responsible for form deprivation myopia and perhaps emmetropization. Recovery from diffuser-induced form deprivation myopia was apparent in some animals, in contrast to that reported for visual deprivation by lid-suturing, and appears more prevalent in the younger animals. PMID:15914598

  5. Crowding is proportional to visual acuity in young and aging eyes.

    PubMed

    Yehezkel, Oren; Sterkin, Anna; Lev, Maria; Polat, Uri

    2015-01-01

    Spatial crowding decreases object recognition and conscious visual perception in clutter. In a previous study we used brief presentation times to reveal the effects of a crowded presentation in the fovea. Here we aimed to test the relationships between varying visual acuity (VA) and crowding in the fovea, under the assumption that in uncorrected presbyopia, the processing is relatively normal, whereas the retinal input is blurred. We tested whether normal participants whose near VA is gradually reduced due to age-related deterioration (presbyopia, or "aging eye") will show an acuity-dependent increase in foveal crowding. We used brief presentations and acuity-threshold letter targets in order to magnify the crowding-effect amplitude in the fovea. A total of 195 participants with an age range of 20-68 years and an average of 44.3 ± 11.7 years (M ± SD) were divided into four age groups, all without any optical correction for the near distance. Our findings show that crowding is proportional to VA. This proportionality is affected by VA-age dependency, with a nonlinear S-shaped pattern: A steep VA reduction begins to develop, which is compatible with the normal onset age of presbyopia symptoms and a saturation in the VA-age dependency in the oldest age group, for which we propose a VA-eccentricity account. Finally, there is a high variance in the crowding amplitude in the young, even before the onset age of presbyopia symptoms, suggesting crowding conditions with limited presentation times as a highly sensitive measure of VA, which predicts visual performance in complex tasks, such as reading. PMID:26129861

  6. The Effects of Visual Stimuli on the Spoken Narrative Performance of School-Age African American Children

    ERIC Educational Resources Information Center

    Mills, Monique T.

    2015-01-01

    Purpose: This study investigated the fictional narrative performance of school-age African American children across 3 elicitation contexts that differed in the type of visual stimulus presented. Method: A total of 54 children in Grades 2 through 5 produced narratives across 3 different visual conditions: no visual, picture sequence, and single…

  7. Effects of gestational length, gender, postnatal age, and birth order on visual contrast sensitivity in infants

    PubMed Central

    Dobkins, Karen R.; Bosworth, Rain G.; McCleery, Joseph P.

    2010-01-01

    To investigate effects of visual experience versus preprogrammed mechanisms on visual development, we used multiple regression analysis to determine the extent to which a variety of variables (that differ in the extent to which they are tied to visual experience) predict luminance and chromatic (red/green) contrast sensitivity (CS), which are mediated by the magnocellular (M) and parvocellular (P) subcortical pathways, respectively. Our variables included gestational length (GL), birth weight (BW), gender, postnatal age (PNA), and birth order (BO). Two-month-olds (n = 60) and 6-month-olds (n = 122) were tested. Results revealed that (1) at 2 months, infants with longer GL have higher luminance CS; (2) at both ages, CS significantly increases over a ~21-day range of PNA, but this effect is stronger in 2- than 6-month-olds and stronger for chromatic than luminance CS; (3) at 2 months, boys have higher luminance CS than girls; and (4) at 2 months, firstborn infants have higher CS, while at 6 months, non-firstborn infants have higher CS. The results for PNA/GL are consistent with the possibility that P pathway development is more influenced by variables tied to visual experience (PNA), while M pathway development is more influenced by variables unrelated to visual experience (GL). Other variables, including prenatal environment, are also discussed. PMID:19810800

  8. A visual warning system to reduce struck-by or pinning accidents involving mobile mining equipment.

    PubMed

    Sammarco, J; Gallagher, S; Mayton, A; Srednicki, J

    2012-11-01

    This paper describes an experiment to examine whether a visual warning system can improve detection of moving machine hazards that could result in struck-by or pinning accidents. Thirty-six participants, twelve each in one of three age groups, participated in the study. A visual warning system capable of providing four different modes of warning was installed on a continuous mining machine that is used to mine coal. The speed of detecting various machine movements was recorded with and without the visual warning system. The average speed of detection for forward and reverse machine movements was reduced by 75% when using the flashing mode of the visual warning system. This translated to 0.485 m of machine travel for the fast speed condition of 19.8 m/min, which is significant in the context of the confined spaces of a mine. There were no statistically significant differences among age groups in the ability to detect machine movements for the visual warning modes in this study. The visual warning system shows promise as a safety intervention for reducing struck-by or pinning accidents involving continuous mining machines. The methods and results of this study could be applied to other moving machinery used in mining or other industries where moving machinery poses struck-by or pinning hazards. PMID:22503737

  9. Cognitive aging on latent constructs for visual processing capacity: a novel structural equation modeling framework with causal assumptions based on a theory of visual attention

    PubMed Central

    Nielsen, Simon; Wilms, L. Inge

    2015-01-01

    We examined the effects of normal aging on visual cognition in a sample of 112 healthy adults aged 60–75. A testbattery was designed to capture high-level measures of visual working memory and low-level measures of visuospatial attention and memory. To answer questions of how cognitive aging affects specific aspects of visual processing capacity, we used confirmatory factor analyses in Structural Equation Modeling (SEM; Model 2), informed by functional structures that were modeled with path analyses in SEM (Model 1). The results show that aging effects were selective to measures of visual processing speed compared to visual short-term memory (VSTM) capacity (Model 2). These results are consistent with some studies reporting selective aging effects on processing speed, and inconsistent with other studies reporting aging effects on both processing speed and VSTM capacity. In the discussion we argue that this discrepancy may be mediated by differences in age ranges, and variables of demography. The study demonstrates that SEM is a sensitive method to detect cognitive aging effects even within a narrow age-range, and a useful approach to structure the relationships between measured variables, and the cognitive functional foundation they supposedly represent. PMID:25642206

  10. The visual system of male scale insects

    NASA Astrophysics Data System (ADS)

    Buschbeck, Elke K.; Hauser, Martin

    2009-03-01

    Animal eyes generally fall into two categories: (1) their photoreceptive array is convex, as is typical for camera eyes, including the human eye, or (2) their photoreceptive array is concave, as is typical for the compound eye of insects. There are a few rare examples of the latter eye type having secondarily evolved into the former one. When viewed in a phylogenetic framework, the head morphology of a variety of male scale insects suggests that this group could be one such example. In the Margarodidae (Hemiptera, Coccoidea), males have been described as having compound eyes, while males of some more derived groups only have two single-chamber eyes on each side of the head. Those eyes are situated in the place occupied by the compound eye of other insects. Since male scale insects tend to be rare, little is known about how their visual systems are organized, and what anatomical traits are associated with this evolutionary transition. In adult male Margarodidae, one single-chamber eye (stemmateran ocellus) is present in addition to a compound eye-like region. Our histological investigation reveals that the stemmateran ocellus has an extended retina which is formed by concrete clusters of receptor cells that connect to its own first-order neuropil. In addition, we find that the ommatidia of the compound eyes also share several anatomical characteristics with simple camera eyes. These include shallow units with extended retinas, each of which is connected by its own small nerve to the lamina. These anatomical changes suggest that the margarodid compound eye represents a transitional form to the giant unicornal eyes that have been described in more derived species.

  11. Test report, earth orbiter teleoperator visual system evaluation program

    NASA Technical Reports Server (NTRS)

    Kirkpatrick, M.; Shields, N. L., Jr.; Malone, T. B.

    1974-01-01

    Work carried out to identify human performance requirements for remotely manned system is reported. Specifically, an evaluation was made of the human visual system. Data cover distance estimation 4, solid target alignment 2, motion detection 1, and motion detection 2.

  12. [Research of the visual electrophysiology record system based on DSP].

    PubMed

    Xiong, Kai; Hou, Min-Xian; Ye, Guan-Rong

    2005-03-01

    An application of digital signal processor (DSP) in the visual electrophysiology record system is presented in this paper. The system's design and implementation are described in detail. Results of its simulation and the clinical experiments are acceptable. PMID:16011113

  13. Age Differential Effects of Severity of Visual Impairment on Mortality among Older Adults in China

    PubMed Central

    Gu, Danan; Zhou, Junshan; Yong, Vanessa; Sautter, Jessica; Saito, Yasuhiko

    2015-01-01

    We use a population-based longitudinal survey in China from 2002 to 2005 to examine age differentials in the association between severity of visual impairment and mortality risk in older adults. Controlling for numerous factors and baseline health, a substantial age difference is found. Young-old women and men aged 65–79 with severe visual impairments have 161% (hazard ratio=2.61) and 52% (hazard ratio =1.52) higher risk of death respectively as compared to their unimpaired counterparts. Mild impairment does not increase mortality risk among young-old adults, while both mild and severe impairment increase mortality risk by 33% and 32% for women and 24% and 34% for men among the oldest-old as a whole when all factors are controlled for. We conclude that visual impairment is an independent predictor of mortality and severe visual impairment likely plays a stronger role in determining mortality risk among young-old adults than among the oldest-old. PMID:25474802

  14. Temporal entrainment of visual attention in children: effects of age and deafness

    PubMed Central

    Dye, Matthew W. G.

    2014-01-01

    The major documented effect of auditory deprivation on visual processing is enhanced spatial attention, in particular to the visual periphery and to moving stimuli. However, there is a parallel literature that has reported deficits in temporal aspects of visual processing in individuals with profound hearing losses. This study builds upon previous work showing possible deficits in processing of rapid serial visual presentation streams in deaf children [Restorative Neurology and Neuroscience (2010), 28, 181–192]. Deaf native signers of American Sign Language and hearing children and adults were asked to perform a 2-AFC identification task with a visual target embedded in a stream of visual stimuli presented at 6 Hz. Both children and adults displayed attentional awakening, whereby target identification accuracy improved as the number of stimuli preceding the target increased. For deaf children, however, this awakening effect was less pronounced than that observed in hearing children, interpreted as difficulty sustaining entrainment to the stimulus stream. The data provide the first account of attentional awakening in children, showing that it improves across the 6–13 year age range. They also provide additional support to the possibility of domain-general alterations in the processing of temporal information in the absence of auditory input. PMID:25236173

  15. Temporal entrainment of visual attention in children: effects of age and deafness.

    PubMed

    Dye, Matthew W G

    2014-12-01

    The major documented effect of auditory deprivation on visual processing is enhanced spatial attention, in particular to the visual periphery and to moving stimuli. However, there is a parallel literature that has reported deficits in temporal aspects of visual processing in individuals with profound hearing losses. This study builds upon previous work showing possible deficits in processing of rapid serial visual presentation streams in deaf children [Restorative Neurology and Neuroscience (2010), 28, 181-192]. Deaf native signers of American Sign Language and hearing children and adults were asked to perform a 2-AFC identification task with a visual target embedded in a stream of visual stimuli presented at 6 Hz. Both children and adults displayed attentional awakening, whereby target identification accuracy improved as the number of stimuli preceding the target increased. For deaf children, however, this awakening effect was less pronounced than that observed in hearing children, interpreted as difficulty sustaining entrainment to the stimulus stream. The data provide the first account of attentional awakening in children, showing that it improves across the 6-13 year age range. They also provide additional support to the possibility of domain-general alterations in the processing of temporal information in the absence of auditory input. PMID:25236173

  16. An annotation system for 3D fluid flow visualization

    NASA Technical Reports Server (NTRS)

    Loughlin, Maria M.; Hughes, John F.

    1995-01-01

    Annotation is a key activity of data analysis. However, current systems for data analysis focus almost exclusively on visualization. We propose a system which integrates annotations into a visualization system. Annotations are embedded in 3D data space, using the Post-it metaphor. This embedding allows contextual-based information storage and retrieval, and facilitates information sharing in collaborative environments. We provide a traditional database filter and a Magic Lens filter to create specialized views of the data. The system has been customized for fluid flow applications, with features which allow users to store parameters of visualization tools and sketch 3D volumes.

  17. Visual Field Function in School-Aged Children with Spastic Unilateral Cerebral Palsy Related to Different Patterns of Brain Damage

    ERIC Educational Resources Information Center

    Jacobson, Lena; Rydberg, Agneta; Eliasson, Ann-Christin; Kits, Annika; Flodmark, Olof

    2010-01-01

    Aim: To relate visual field function to brain morphology in children with unilateral cerebral palsy (CP). Method: Visual field function was assessed using the confrontation technique and Goldmann perimetry in 29 children (15 males, 14 females; age range 7-17y, median age 11y) with unilateral CP classified at Gross Motor Function Classification…

  18. Framework for an Information Visualization System

    Energy Science and Technology Software Center (ESTSC)

    2006-08-11

    The Program is a suite of Windows-based software applications and services for ingesting, storing, and analyzing large quantities of disparate inforamtion. The software supports the ingestion and storage of any information that can be represented in eXtensible Markup Language (XML) format. Stored information can be subsequently retrieved via search operations, then "visualized" in multiple ways using a client application that supports a variety of analytical functions. Visualization capabilities include tools for depicting a variety ofmore » relationships that may be present in the information, including geospatial, temporal, topical, categorical, and network relationships.« less

  19. History of visual systems in the Systems Engineering Simulator

    NASA Technical Reports Server (NTRS)

    Christianson, David C.

    1989-01-01

    The Systems Engineering Simulator (SES) houses a variety of real-time computer generated visual systems. The earliest machine dates from the mid-1960's and is one of the first real-time graphics systems in the world. The latest acquisition is the state-of-the-art Evans and Sutherland CT6. Between the span of time from the mid-1960's to the late 1980's, tremendous strides have been made in the real-time graphics world. These strides include advances in both software and hardware engineering. The purpose is to explore the history of the development of these real-time computer generated image systems from the first machine to the present. Hardware advances as well as software algorithm changes are presented. This history is not only quite interesting but also provides us with a perspective with which we can look backward and forward.

  20. Age-related changes in auditory and visual interactions in temporal rate perception

    PubMed Central

    Brooks, Cassandra J.; Anderson, Andrew J.; Roach, Neil W.; McGraw, Paul V.; McKendrick, Allison M.

    2015-01-01

    We investigated how aging affects the integration of temporal rate for auditory flutter (amplitude modulation) presented with visual flicker. Since older adults were poorer at detecting auditory amplitude modulation, modulation depth was individually adjusted so that temporal rate was equally discriminable for 10 Hz flutter and flicker, thereby balancing the reliability of rate information available to each sensory modality. With age-related sensory differences normalized in this way, rate asynchrony skewed both auditory and visual rate judgments to the same extent in younger and older adults. Therefore, reliability-based weighting of temporal rate is preserved in older adults. Concurrent presentation of synchronous 10 Hz flicker and flutter improved temporal rate discrimination consistent with statistically optimal integration in younger but not older adults. In a control experiment, younger adults were presented with the same physical auditory stimulus as older adults. This time, rate asynchrony skewed perceived rate with greater auditory weighting rather than balanced integration. Taken together, our results indicate that integration of discrepant auditory and visual rates is not altered due to the healthy aging process once sensory deficits are accounted for, but that aging does abolish the minor improvement in discrimination performance seen in younger observers when concordant rates are integrated. PMID:26624937

  1. The simple fly larval visual system can process complex images.

    PubMed

    Justice, Elizabeth Daubert; Macedonia, Nicholas James; Hamilton, Catherine; Condron, Barry

    2012-01-01

    Animals that have simple eyes are thought to only detect crude visual detail such as light level. However, predatory insect larvae using a small number of visual inputs seem to distinguish complex image targets. Here we show that Drosophila melanogaster larvae, which have 12 photoreceptor cells per hemisphere, are attracted to distinct motions of other, tethered larvae and that this recognition requires the visual system but not the olfactory system. In addition, attraction to tethered larvae still occurs across a clear plastic barrier, does not occur significantly in the dark and attraction occurs to a computer screen movie of larval motion. By altering the artificial attractant movie, we conclude that visual recognition involves both spatial and temporal components. Our results demonstrate that a simple but experimentally tractable visual system can distinguish complex images and that processing in the relatively large central brain may compensate for the simple input. PMID:23093193

  2. Brightness Induction and Suprathreshold Vision: Effects of Age and Visual Field

    PubMed Central

    McCourt, Mark E.; Leone, Lynnette M.; Blakeslee, Barbara

    2014-01-01

    A variety of visual capacities show significant age-related alterations. We assessed suprathreshold contrast and brightness perception across the lifespan in a large sample of healthy participants (N = 155; 142) ranging in age from 16–80 years. Experiment 1 used a quadrature-phase motion cancelation technique (Blakeslee & McCourt, 2008) to measure canceling contrast (in central vision) for induced gratings at two temporal frequencies (1 Hz and 4 Hz) at two test field heights (0.5° or 2° × 38.7°; 0.052 c/d). There was a significant age-related reduction in canceling contrast at 4 Hz, but not at 1 Hz. We find no age-related change in induction magnitude in the 1 Hz condition. We interpret the age-related decline in grating induction magnitude at 4 Hz to reflect a diminished capacity for inhibitory processing at higher temporal frequencies. In Experiment 2 participants adjusted the contrast of a matching grating (0.5° or 2° × 38.7°; 0.052 c/d) to equal that of both real (30% contrast, 0.052 c/d) and induced (McCourt, 1982) standard gratings (100% inducing grating contrast; 0.052 c/d). Matching gratings appeared in the upper visual field (UVF) and test gratings appeared in the lower visual field (LVF), and vice versa, at eccentricities of ±7.5°. Average induction magnitude was invariant with age for both test field heights. There was a significant age-related reduction in perceived contrast of stimuli in the LVF versus UVF for both real and induced gratings. PMID:25462024

  3. Visualizing Terrestrial and Aquatic Systems in 3-D

    EPA Science Inventory

    The environmental modeling community has a long-standing need for affordable, easy-to-use tools that support 3-D visualization of complex spatial and temporal model output. The Visualization of Terrestrial and Aquatic Systems project (VISTAS) aims to help scientists produce effe...

  4. Inputs to prefrontal cortex support visual recognition in the aging brain

    PubMed Central

    Gilbert, Jessica R.; Moran, Rosalyn J.

    2016-01-01

    Predictive coding models of brain function propose that top-down cortical signals promote efficient neural codes by carrying predictions of upcoming sensory events. We hypothesized that older brains would employ these codes more prominently given their longer repertoire of sensory experience. We measured the connectivity underlying stimulus-evoked responses in cortical visual networks using electroencephalography and dynamic causal modeling and found that in young adults with reported normal or corrected-to-normal vision, signals propagated from early visual regions and reverberated along reciprocal connections to temporal, parietal and frontal cortices, while in contrast, the network was driven by both early visual and prefrontal inputs in older adults with reported normal or corrected-to-normal vision. Previously thought of as exceptions to the rule of bottom-up signal propagation, our results demonstrate a prominent role for prefrontal inputs in driving vision in aged brains in line with lifespan-dependent predictive neural codes. PMID:27550752

  5. Inputs to prefrontal cortex support visual recognition in the aging brain.

    PubMed

    Gilbert, Jessica R; Moran, Rosalyn J

    2016-01-01

    Predictive coding models of brain function propose that top-down cortical signals promote efficient neural codes by carrying predictions of upcoming sensory events. We hypothesized that older brains would employ these codes more prominently given their longer repertoire of sensory experience. We measured the connectivity underlying stimulus-evoked responses in cortical visual networks using electroencephalography and dynamic causal modeling and found that in young adults with reported normal or corrected-to-normal vision, signals propagated from early visual regions and reverberated along reciprocal connections to temporal, parietal and frontal cortices, while in contrast, the network was driven by both early visual and prefrontal inputs in older adults with reported normal or corrected-to-normal vision. Previously thought of as exceptions to the rule of bottom-up signal propagation, our results demonstrate a prominent role for prefrontal inputs in driving vision in aged brains in line with lifespan-dependent predictive neural codes. PMID:27550752

  6. The eye and visual nervous system: anatomy, physiology and toxicology.

    PubMed Central

    McCaa, C S

    1982-01-01

    The eyes are at risk to environmental injury by direct exposure to airborne pollutants, to splash injury from chemicals and to exposure via the circulatory system to numerous drugs and bloodborne toxins. In addition, drugs or toxins can destroy vision by damaging the visual nervous system. This review describes the anatomy and physiology of the eye and visual nervous system and includes a discussion of some of the more common toxins affecting vision in man. Images FIGURE 1. FIGURE 2. PMID:7084144

  7. Visualization of an entangled channel spin-1 system

    SciTech Connect

    Sirsi, Swarnamala; Adiga, Veena

    2010-08-15

    Covariance matrix formalism gives powerful entanglement criteria for continuous as well as finite dimensional systems. We use this formalism to study a mixed channel spin-1 system which is well known in nuclear reactions. A spin-j state can be visualized as being made up of 2j spinors which are represented by a constellation of 2j points on a Bloch sphere using Majorana construction. We extend this formalism to visualize an entangled mixed spin-1 system.

  8. Effects of Aging on the Digestive System

    MedlinePlus

    ... Mail Facebook TwitterTitle Google+ LinkedIn Home Digestive Disorders Biology of the Digestive System Effects of Aging on ... Version. DOCTORS: Click here for the Professional Version Biology of the Digestive System Overview of the Digestive ...

  9. Aging changes in the nervous system

    MedlinePlus

    ... ency/article/004023.htm Aging changes in the nervous system To use the sharing features on this page, please enable JavaScript. The brain and nervous system are your body's central control center. They control ...

  10. Own-race and own-age biases facilitate visual awareness of faces under interocular suppression

    PubMed Central

    Stein, Timo; End, Albert; Sterzer, Philipp

    2014-01-01

    The detection of a face in a visual scene is the first stage in the face processing hierarchy. Although all subsequent, more elaborate face processing depends on the initial detection of a face, surprisingly little is known about the perceptual mechanisms underlying face detection. Recent evidence suggests that relatively hard-wired face detection mechanisms are broadly tuned to all face-like visual patterns as long as they respect the typical spatial configuration of the eyes above the mouth. Here, we qualify this notion by showing that face detection mechanisms are also sensitive to face shape and facial surface reflectance properties. We used continuous flash suppression (CFS) to render faces invisible at the beginning of a trial and measured the time upright and inverted faces needed to break into awareness. Young Caucasian adult observers were presented with faces from their own race or from another race (race experiment) and with faces from their own age group or from another age group (age experiment). Faces matching the observers’ own race and age group were detected more quickly. Moreover, the advantage of upright over inverted faces in overcoming CFS, i.e., the face inversion effect (FIE), was larger for own-race and own-age faces. These results demonstrate that differences in face shape and surface reflectance influence access to awareness and configural face processing at the initial detection stage. Although we did not collect data from observers of another race or age group, these findings are a first indication that face detection mechanisms are shaped by visual experience with faces from one’s own social group. Such experience-based fine-tuning of face detection mechanisms may equip in-group faces with a competitive advantage for access to conscious awareness. PMID:25136308

  11. Own-race and own-age biases facilitate visual awareness of faces under interocular suppression.

    PubMed

    Stein, Timo; End, Albert; Sterzer, Philipp

    2014-01-01

    The detection of a face in a visual scene is the first stage in the face processing hierarchy. Although all subsequent, more elaborate face processing depends on the initial detection of a face, surprisingly little is known about the perceptual mechanisms underlying face detection. Recent evidence suggests that relatively hard-wired face detection mechanisms are broadly tuned to all face-like visual patterns as long as they respect the typical spatial configuration of the eyes above the mouth. Here, we qualify this notion by showing that face detection mechanisms are also sensitive to face shape and facial surface reflectance properties. We used continuous flash suppression (CFS) to render faces invisible at the beginning of a trial and measured the time upright and inverted faces needed to break into awareness. Young Caucasian adult observers were presented with faces from their own race or from another race (race experiment) and with faces from their own age group or from another age group (age experiment). Faces matching the observers' own race and age group were detected more quickly. Moreover, the advantage of upright over inverted faces in overcoming CFS, i.e., the face inversion effect (FIE), was larger for own-race and own-age faces. These results demonstrate that differences in face shape and surface reflectance influence access to awareness and configural face processing at the initial detection stage. Although we did not collect data from observers of another race or age group, these findings are a first indication that face detection mechanisms are shaped by visual experience with faces from one's own social group. Such experience-based fine-tuning of face detection mechanisms may equip in-group faces with a competitive advantage for access to conscious awareness. PMID:25136308

  12. Visual Performance in Patients with Neovascular Age-Related Macular Degeneration Undergoing Treatment with Intravitreal Ranibizumab

    PubMed Central

    Loughman, James; Nolan, John M.; Stack, Jim; Pesudovs, Konrad; Meagher, Katherine A.; Beatty, Stephen

    2013-01-01

    Purpose. To assess visual function and its response to serial intravitreal ranibizumab (Lucentis, Genentech) in patients with neovascular age-related macular degeneration (nv-AMD). Methods. Forty-seven eyes of 47 patients with nv-AMD, and corrected distance visual acuity (CDVA) logMAR 0.7 or better, undergoing intravitreal injections of ranibizumab, were enrolled into this prospective study. Visual function was assessed using a range of psychophysical tests, while mean foveal thickness (MFT) was determined by optical coherence tomography (OCT). Results. Group mean (±sd) MFT reduced significantly from baseline (233 (±59)) to exit (205 (±40)) (P = 0.001). CDVA exhibited no change between baseline and exit visits (P = 0.48 and P = 0.31, resp.). Measures of visual function that did exhibit statistically significant improvements (P < 0.05 for all) included reading acuity, reading speed, mesopic and photopic contrast sensitivity (CS), mesopic and photopic glare disability (GD), and retinotopic ocular sensitivity (ROS) at all eccentricities. Conclusion. Eyes with nv-AMD undergoing intravitreal ranibizumab injections exhibit improvements in many parameters of visual function. Outcome measures other than CDVA, such as CS, GD, and ROS, should not only be considered in the design of studies investigating nv-AMD, but also in treatment and retreatment strategies for patients with the condition. PMID:23533703

  13. Visual Analytics for Complex Engineering Systems: Hybrid Visual Steering of Simulation Ensembles.

    PubMed

    Matković, Krešimir; Gračanin, Denis; Splechtna, Rainer; Jelović, Mario; Stehno, Benedikt; Hauser, Helwig; Purgathofer, Werner

    2014-12-01

    In this paper we propose a novel approach to hybrid visual steering of simulation ensembles. A simulation ensemble is a collection of simulation runs of the same simulation model using different sets of control parameters. Complex engineering systems have very large parameter spaces so a naïve sampling can result in prohibitively large simulation ensembles. Interactive steering of simulation ensembles provides the means to select relevant points in a multi-dimensional parameter space (design of experiment). Interactive steering efficiently reduces the number of simulation runs needed by coupling simulation and visualization and allowing a user to request new simulations on the fly. As system complexity grows, a pure interactive solution is not always sufficient. The new approach of hybrid steering combines interactive visual steering with automatic optimization. Hybrid steering allows a domain expert to interactively (in a visualization) select data points in an iterative manner, approximate the values in a continuous region of the simulation space (by regression) and automatically find the "best" points in this continuous region based on the specified constraints and objectives (by optimization). We argue that with the full spectrum of optimization options, the steering process can be improved substantially. We describe an integrated system consisting of a simulation, a visualization, and an optimization component. We also describe typical tasks and propose an interactive analysis workflow for complex engineering systems. We demonstrate our approach on a case study from automotive industry, the optimization of a hydraulic circuit in a high pressure common rail Diesel injection system. PMID:26356894

  14. Visual function in term infants with hypoxic-ischaemic insults: correlation with neurodevelopment at 2 years of age

    PubMed Central

    Mercuri, E.; Haataja, L.; Guzzetta, A.; Anker, S.; Cowan, F.; Rutherford, M.; Andrew, R.; Braddick, O.; Cioni, G.; Dubowitz, L.; Atkinson, J.

    1999-01-01

    AIMS—To determine if there is any association between the findings of visual assessment performed at the age of 5 months and neurodevelopmental outcome at the age of 2 years in children who have sustained hypoxic-ischaemic insults.
METHODS—Twenty nine term infants with hypoxic-ischaemic encephalopathy and/or brain lesions on neonatal magnetic resonance imaging (MRI) were prospectively evaluated. At 5 months of age all the infants had their visual function assessed using the Atkinson Battery of Child Development for Examining Functional Vision, which includes the assessments of optokinetic nystagmus (OKN), acuity, visual fields, fixation shift and phase and orientation reversal visual evoked potentials. At 2 years of age the children had a structured neurological evaluation and a Griffiths developmental assessment.
RESULTS—There was good correlation between the extent of the early detected visual impairment and both neuromotor and global development. Children with more than three out of five abnormal visual tests at 5 months of age tended to have abnormal neurological examination results and abnormal developmental quotients. Children with three or fewer abnormalities tended to have developmental quotients in the normal range; the level of their performance, however, was still related to the number of visual tests passed.
CONCLUSIONS—Individual visual tests can provide important prognostic information. While abnormal OKN and acuity were always associated with abnormal outcome, normal results on visual evoked potentials and fixation shift tended to be associated with normal outcome.

 PMID:10325784

  15. The effects of age and experience on memory for visually presented music.

    PubMed

    Meinz, E J; Salthouse, T A

    1998-01-01

    Increased age is often associated with lower levels of performance in tests of memory for spatial information. The primary question in the current study was whether this relationship could be moderated as a function of one's relevant experience and/or knowledge. Stimulus materials consisted of short (7-11 note), visually presented musical melodies and structurally equivalent nonmusical stimuli. Participants (N = 128) were recruited from a wide range of age and experience levels. Although there were strong main effects of age and experience on memory for music, there was no evidence that the age-related differences in memory for these stimuli were smaller for individuals with moderate to large amounts of experience with music. PMID:9469173

  16. A steady state visually evoked potential investigation of memory and ageing.

    PubMed

    Macpherson, Helen; Pipingas, Andrew; Silberstein, Richard

    2009-04-01

    Old age is generally accompanied by a decline in memory performance. Specifically, neuroimaging and electrophysiological studies have revealed that there are age-related changes in the neural correlates of episodic and working memory. This study investigated age-associated changes in the steady state visually evoked potential (SSVEP) amplitude and latency associated with memory performance. Participants were 15 older (59-67 years) and 14 younger (20-30 years) adults who performed an object working memory (OWM) task and a contextual recognition memory (CRM) task, whilst the SSVEP was recorded from 64 electrode sites. Retention of a single object in the low demand OWM task was characterised by smaller frontal SSVEP amplitude and latency differences in older adults than in younger adults, indicative of an age-associated reduction in neural processes. Recognition of visual images in the more difficult CRM task was accompanied by larger, more sustained SSVEP amplitude and latency decreases over temporal parietal regions in older adults. In contrast, the more transient, frontally mediated pattern of activity demonstrated by younger adults suggests that younger and older adults utilize different neural resources to perform recognition judgements. The results provide support for compensatory processes in the aging brain; at lower task demands, older adults demonstrate reduced neural activity, whereas at greater task demands neural activity is increased. PMID:19135766

  17. Effects of healthy ageing on precision and binding of object location in visual short term memory.

    PubMed

    Pertzov, Yoni; Heider, Maike; Liang, Yuying; Husain, Masud

    2015-03-01

    Visual short term memory (STM) declines as people get older, but the nature of this deterioration is not well understood. We tested 139 healthy subjects (19-83 years) who were first required to identify a previously seen object and then report its location using a touchscreen. Results demonstrated an age-related decline in both object identification and localization. Deterioration in localization performance was apparent even when only 1 item had to be remembered, worsening disproportionately with increasing memory load. Thus, age-dependent memory degradation cannot be explained simply by a decrease in the number of items that can be held in visual STM but rather by the precision with which they are recalled. More important, there was no evidence for a significant decrease in object-location binding with increasing age. Thus, although precision for object identity and location declines with age, the ability to associate object identity to its location seems to remain unimpaired. As it has been reported that binding deficits in STM might be the first cognitive signs of early Alzheimer's disease (AD), the finding that object-location binding processes are relatively intact with normal aging supports the possible suitability of using misbinding as an index measures for probing early diagnosis of AD. PMID:25528066

  18. Brain activation by visual erotic stimuli in healthy middle aged males.

    PubMed

    Kim, S W; Sohn, D W; Cho, Y-H; Yang, W S; Lee, K-U; Juh, R; Ahn, K-J; Chung, Y-A; Han, S-I; Lee, K H; Lee, C U; Chae, J-H

    2006-01-01

    The objective of the present study was to identify brain centers, whose activity changes are related to erotic visual stimuli in healthy, heterosexual, middle aged males. Ten heterosexual, right-handed males with normal sexual function were entered into the present study (mean age 52 years, range 46-55). All potential subjects were screened over 1 h interview, and were encouraged to fill out questionnaires including the Brief Male Sexual Function Inventory. All subjects with a history of sexual arousal disorder or erectile dysfunction were excluded. We performed functional brain magnetic resonance imaging (fMRI) in male volunteers when an alternatively combined erotic and nonerotic film was played for 14 min and 9 s. The major areas of activation associated with sexual arousal to visual stimuli were occipitotemporal area, anterior cingulate gyrus, insula, orbitofrontal cortex, caudate nucleus. However, hypothalamus and thalamus were not activated. We suggest that the nonactivation of hypothalamus and thalamus in middle aged males may be responsible for the lesser physiological arousal in response to the erotic visual stimuli. PMID:16467858

  19. Age Differences in Visual-Auditory Self-Motion Perception during a Simulated Driving Task.

    PubMed

    Ramkhalawansingh, Robert; Keshavarz, Behrang; Haycock, Bruce; Shahab, Saba; Campos, Jennifer L

    2016-01-01

    Recent evidence suggests that visual-auditory cue integration may change as a function of age such that integration is heightened among older adults. Our goal was to determine whether these changes in multisensory integration are also observed in the context of self-motion perception under realistic task constraints. Thus, we developed a simulated driving paradigm in which we provided older and younger adults with visual motion cues (i.e., optic flow) and systematically manipulated the presence or absence of congruent auditory cues to self-motion (i.e., engine, tire, and wind sounds). Results demonstrated that the presence or absence of congruent auditory input had different effects on older and younger adults. Both age groups demonstrated a reduction in speed variability when auditory cues were present compared to when they were absent, but older adults demonstrated a proportionally greater reduction in speed variability under combined sensory conditions. These results are consistent with evidence indicating that multisensory integration is heightened in older adults. Importantly, this study is the first to provide evidence to suggest that age differences in multisensory integration may generalize from simple stimulus detection tasks to the integration of the more complex and dynamic visual and auditory cues that are experienced during self-motion. PMID:27199829

  20. Age Differences in Visual-Auditory Self-Motion Perception during a Simulated Driving Task

    PubMed Central

    Ramkhalawansingh, Robert; Keshavarz, Behrang; Haycock, Bruce; Shahab, Saba; Campos, Jennifer L.

    2016-01-01

    Recent evidence suggests that visual-auditory cue integration may change as a function of age such that integration is heightened among older adults. Our goal was to determine whether these changes in multisensory integration are also observed in the context of self-motion perception under realistic task constraints. Thus, we developed a simulated driving paradigm in which we provided older and younger adults with visual motion cues (i.e., optic flow) and systematically manipulated the presence or absence of congruent auditory cues to self-motion (i.e., engine, tire, and wind sounds). Results demonstrated that the presence or absence of congruent auditory input had different effects on older and younger adults. Both age groups demonstrated a reduction in speed variability when auditory cues were present compared to when they were absent, but older adults demonstrated a proportionally greater reduction in speed variability under combined sensory conditions. These results are consistent with evidence indicating that multisensory integration is heightened in older adults. Importantly, this study is the first to provide evidence to suggest that age differences in multisensory integration may generalize from simple stimulus detection tasks to the integration of the more complex and dynamic visual and auditory cues that are experienced during self-motion. PMID:27199829

  1. Systems biology approaches in aging research.

    PubMed

    Chauhan, Anuradha; Liebal, Ulf W; Vera, Julio; Baltrusch, Simone; Junghanß, Christian; Tiedge, Markus; Fuellen, Georg; Wolkenhauer, Olaf; Köhling, Rüdiger

    2015-01-01

    Aging is a systemic process which progressively manifests itself at multiple levels of structural and functional organization from molecular reactions and cell-cell interactions in tissues to the physiology of an entire organ. There is ever increasing data on biomedical relevant network interactions for the aging process at different scales of time and space. To connect the aging process at different structural, temporal and spatial scales, extensive systems biological approaches need to be deployed. Systems biological approaches can not only systematically handle the large-scale datasets (like high-throughput data) and the complexity of interactions (feedback loops, cross talk), but also can delve into nonlinear behaviors exhibited by several biological processes which are beyond intuitive reasoning. Several public-funded agencies have identified the synergistic role of systems biology in aging research. Using one of the notable public-funded programs (GERONTOSYS), we discuss how systems biological approaches are helping the scientists to find new frontiers in aging research. We elaborate on some systems biological approaches deployed in one of the projects of the consortium (ROSage). The systems biology field in aging research is at its infancy. It is open to adapt existing systems biological methodologies from other research fields and devise new aging-specific systems biological methodologies. PMID:25341520

  2. Conceptual design study for a teleoperator visual system, phase 1

    NASA Technical Reports Server (NTRS)

    Adams, D.; Grant, C.; Johnson, C.; Meirick, R.; Polhemus, C.; Ray, A.; Rittenhouse, D.; Skidmore, R.

    1972-01-01

    Results are reported for work performed during the first phase of the conceptual design study for a teleoperator visual system. This phase consists of four tasks: General requirements, concept development, subsystem requirements and analysis, and concept evaluation.

  3. Aging and brain rejuvenation as systemic events

    PubMed Central

    Bouchard, Jill; Villeda, Saul A

    2015-01-01

    The effects of aging were traditionally thought to be immutable, particularly evident in the loss of plasticity and cognitive abilities occurring in the aged central nervous system (CNS). However, it is becoming increasingly apparent that extrinsic systemic manipulations such as exercise, caloric restriction, and changing blood composition by heterochronic parabiosis or young plasma administration can partially counteract this age-related loss of plasticity in the aged brain. In this review, we discuss the process of aging and rejuvenation as systemic events. We summarize genetic studies that demonstrate a surprising level of malleability in organismal lifespan, and highlight the potential for systemic manipulations to functionally reverse the effects of aging in the CNS. Based on mounting evidence, we propose that rejuvenating effects of systemic manipulations are mediated, in part, by blood-borne ‘pro-youthful’ factors. Thus, systemic manipulations promoting a younger blood composition provide effective strategies to rejuvenate the aged brain. As a consequence, we can now consider reactivating latent plasticity dormant in the aged CNS as a means to rejuvenate regenerative, synaptic, and cognitive functions late in life, with potential implications even for extending lifespan. PMID:25327899

  4. Description and performance of the Langley visual landing display system

    NASA Technical Reports Server (NTRS)

    Rollins, J. D.

    1978-01-01

    A television/model board system is described which provides a means of generating a six-degree-of-freedom visual out-the-window scene for the pilot of a simulated aircraft. The hardware and its performance of capability for meeting the visual requirements for a wide range of simulation studies are detailed. Also included is a description of the computer software required for the system. An example of software implementation in a real-time computer program is provided.

  5. Age-related decline of peripheral visual processing: the role of eye movements.

    PubMed

    Beurskens, Rainer; Bock, Otmar

    2012-03-01

    Earlier work suggests that the area of space from which useful visual information can be extracted (useful field of view, UFoV) shrinks in old age. We investigated whether this shrinkage, documented previously with a visual search task, extends to a bimanual tracking task. Young and elderly subjects executed two concurrent tracking tasks with their right and left arms. The separation between tracking displays varied from 3 to 35 cm. Subjects were asked to fixate straight ahead (condition FIX) or were free to move their eyes (condition FREE). Eye position was registered. In FREE, young subjects tracked equally well at all display separations. Elderly subjects produced higher tracking errors, and the difference between age groups increased with display separation. Eye movements were comparable across age groups. In FIX, elderly and young subjects tracked less well at large display separations. Seniors again produced higher tracking errors in FIX, but the difference between age groups did not increase reliably with display separation. However, older subjects produced a substantial number of illicit saccades, and when the effect of those saccades was factored out, the difference between young and older subjects' tracking did increase significantly with display separation in FIX. We conclude that the age-related shrinkage of UFoV, previously documented with a visual search task, is observable with a manual tracking task as well. Older subjects seem to partly compensate their deficit by illicit saccades. Since the deficit is similar in both conditions, it may be located downstream from the convergence of retinal and oculomotor signals. PMID:22179529

  6. The immune system and aging: a review.

    PubMed

    Castelo-Branco, Camil; Soveral, Iris

    2014-01-01

    Abstract The concept of immunosenescence reflects age-related changes in immune responses, both cellular and serological, affecting the process of generating specific responses to foreign and self-antigens. The decline of the immune system with age is reflected in the increased susceptibility to infectious diseases, poorer response to vaccination, increased prevalence of cancer, autoimmune and other chronic diseases. Both innate and adaptive immune responses are affected by the aging process; however, the adaptive response seems to be more affected by the age-related changes in the immune system. Additionally, aged individuals tend to present a chronic low-grade inflammatory state that has been implicated in the pathogenesis of many age-related diseases (atherosclerosis, Alzheimer's disease, osteoporosis and diabetes). However, some individuals arrive to advanced ages without any major health problems, referred to as healthy aging. The immune system dysfunction seems to be somehow mitigated in this population, probably due to genetic and environmental factors yet to be described. In this review, an attempt is made to summarize the current knowledge on how the immune system is affected by the aging process. PMID:24219599

  7. Visually Coupled Systems (VCS): The Virtual Panoramic Display (VPD) System

    NASA Technical Reports Server (NTRS)

    Kocian, Dean F.

    1992-01-01

    The development and impact is described of new visually coupled system (VCS) equipment designed to support engineering and human factors research in the military aircraft cockpit environment. VCS represents an advanced man-machine interface (MMI). Its potential to improve aircrew situational awareness seems enormous, but its superiority over the conventional cockpit MMI has not been established in a conclusive and rigorous fashion. What has been missing is a 'systems' approach to technology advancement that is comprehensive enough to produce conclusive results concerning the operational viability of the VCS concept and verify any risk factors that might be involved with its general use in the cockpit. The advanced VCS configuration described here, was ruggedized for use in military aircraft environments and was dubbed the Virtual Panoramic Display (VPD). It was designed to answer the VCS portion of the systems problem, and is implemented as a modular system whose performance can be tailored to specific application requirements. The overall system concept and the design of the two most important electronic subsystems that support the helmet mounted parts, a new militarized version of the magnetic helmet mounted sight and correspondingly similar helmet display electronics, are discussed in detail. Significant emphasis is given to illustrating how particular design features in the hardware improve overall system performance and support research activities.

  8. A comparative evaluation of visual tracking systems

    NASA Astrophysics Data System (ADS)

    Gatt, Adam; Wong, Sebastien; Kearney, David; Watts, Edward

    2009-05-01

    This paper provides comparative evaluations of two visual object tracking algorithms - the Shape Estimating Filter (SEF), a homogeneous extension of the basic correlation tracker; and its multi-object counterpart the Competitive Attentional Correlation Tracker using Shape (CACTuS). The CACTuS is evaluated comparatively against its predecessor to show direct improvement in tracking effectiveness. Our approach will involve an evaluation framework consisting of a range of modern, peer reviewed tracking performance metrics, allowing for a detailed multi-faceted analysis of tracking results. As such we provide an overview of current performance evaluation methods, including techniques for multi-object tracker evaluation.

  9. Visual scanning behavior is related to recognition performance for own- and other-age faces

    PubMed Central

    Proietti, Valentina; Macchi Cassia, Viola; dell’Amore, Francesca; Conte, Stefania; Bricolo, Emanuela

    2015-01-01

    It is well-established that our recognition ability is enhanced for faces belonging to familiar categories, such as own-race faces and own-age faces. Recent evidence suggests that, for race, the recognition bias is also accompanied by different visual scanning strategies for own- compared to other-race faces. Here, we tested the hypothesis that these differences in visual scanning patterns extend also to the comparison between own and other-age faces and contribute to the own-age recognition advantage. Participants (young adults with limited experience with infants) were tested in an old/new recognition memory task where they encoded and subsequently recognized a series of adult and infant faces while their eye movements were recorded. Consistent with findings on the other-race bias, we found evidence of an own-age bias in recognition which was accompanied by differential scanning patterns, and consequently differential encoding strategies, for own-compared to other-age faces. Gaze patterns for own-age faces involved a more dynamic sampling of the internal features and longer viewing time on the eye region compared to the other regions of the face. This latter strategy was extensively employed during learning (vs. recognition) and was positively correlated to discriminability. These results suggest that deeply encoding the eye region is functional for recognition and that the own-age bias is evident not only in differential recognition performance, but also in the employment of different sampling strategies found to be effective for accurate recognition. PMID:26579056

  10. The Two Visual Systems Hypothesis: New Challenges and Insights from Visual form Agnosic Patient DF.

    PubMed

    Whitwell, Robert L; Milner, A David; Goodale, Melvyn A

    2014-01-01

    Patient DF, who developed visual form agnosia following carbon monoxide poisoning, is still able to use vision to adjust the configuration of her grasping hand to the geometry of a goal object. This striking dissociation between perception and action in DF provided a key piece of evidence for the formulation of Goodale and Milner's Two Visual Systems Hypothesis (TVSH). According to the TVSH, the ventral stream plays a critical role in constructing our visual percepts, whereas the dorsal stream mediates the visual control of action, such as visually guided grasping. In this review, we discuss recent studies of DF that provide new insights into the functional organization of the dorsal and ventral streams. We confirm recent evidence that DF has dorsal as well as ventral brain damage - and that her dorsal-stream lesions and surrounding atrophy have increased in size since her first published brain scan. We argue that the damage to DF's dorsal stream explains her deficits in directing actions at targets in the periphery. We then focus on DF's ability to accurately adjust her in-flight hand aperture to changes in the width of goal objects (grip scaling) whose dimensions she cannot explicitly report. An examination of several studies of DF's grip scaling under natural conditions reveals a modest though significant deficit. Importantly, however, she continues to show a robust dissociation between form vision for perception and form vision-for-action. We also review recent studies that explore the role of online visual feedback and terminal haptic feedback in the programming and control of her grasping. These studies make it clear that DF is no more reliant on visual or haptic feedback than are neurologically intact individuals. In short, we argue that her ability to grasp objects depends on visual feedforward processing carried out by visuomotor networks in her dorsal stream that function in the much the same way as they do in neurologically intact individuals. PMID

  11. Sunfall: a collaborative visual analytics system for astrophysics

    SciTech Connect

    Aragon, Cecilia R.; Aragon, Cecilia R.; Bailey, Stephen J.; Poon, Sarah; Runge, Karl; Thomas, Rollin C.

    2008-07-07

    Computational and experimental sciences produce and collect ever-larger and complex datasets, often in large-scale, multi-institution projects. The inability to gain insight into complex scientific phenomena using current software tools is a bottleneck facing virtually all endeavors of science. In this paper, we introduce Sunfall, a collaborative visual analytics system developed for the Nearby Supernova Factory, an international astrophysics experiment and the largest data volume supernova search currently in operation. Sunfall utilizes novel interactive visualization and analysis techniques to facilitate deeper scientific insight into complex, noisy, high-dimensional, high-volume, time-critical data. The system combines novel image processing algorithms, statistical analysis, and machine learning with highly interactive visual interfaces to enable collaborative, user-driven scientific exploration of supernova image and spectral data. Sunfall is currently in operation at the Nearby Supernova Factory; it is the first visual analytics system in production use at a major astrophysics project.

  12. A phytochemical-rich diet may explain the absence of age-related decline in visual acuity of Amazonian hunter-gatherers in Ecuador.

    PubMed

    London, Douglas S; Beezhold, Bonnie

    2015-02-01

    Myopia is absent in undisturbed hunter-gatherers but ubiquitous in modern populations. The link between dietary phytochemicals and eye health is well established, although transition away from a wild diet has reduced phytochemical variety. We hypothesized that when larger quantities and greater variety of wild, seasonal phytochemicals are consumed in a food system, there will be a reduced prevalence of degenerative-based eye disease as measured by visual acuity. We compared food systems and visual acuity across isolated Amazonian Kawymeno Waorani hunter-gatherers and neighboring Kichwa subsistence agrarians, using dietary surveys, dietary pattern observation, and Snellen Illiterate E visual acuity examinations. Hunter-gatherers consumed more food species (130 vs. 63) and more wild plants (80 vs. 4) including 76 wild fruits, thereby obtaining larger variety and quantity of phytochemicals than agrarians. Visual acuity was inversely related to age only in agrarians (r = -.846, P < .001). As hypothesized, when stratified by age (<40 and ≥ 40 years), Mann-Whitney U tests revealed that hunter-gatherers maintained high visual acuity throughout life, whereas agrarian visual acuity declined (P values < .001); visual acuity of younger participants was high across the board, however, did not differ between groups (P > .05). This unusual absence of juvenile-onset vision problems may be related to local, organic, whole food diets of subsistence food systems isolated from modern food production. Our results suggest that intake of a wider variety of plant foods supplying necessary phytochemicals for eye health may help maintain visual acuity and prevent degenerative eye conditions as humans age. PMID:25636674

  13. One of the most well-established age-related changes in neural activity disappears after controlling for visual acuity.

    PubMed

    Porto, Fábio H G; Tusch, Erich S; Fox, Anne M; Alperin, Brittany R; Holcomb, Phillip J; Daffner, Kirk R

    2016-04-15

    Numerous studies using a variety of imaging techniques have reported age-related differences in neural activity while subjects carry out cognitive tasks. Surprisingly little attention has been paid to the potential impact of age-associated changes in sensory acuity on these findings. Studies in the visual modality frequently report that their subjects had "normal or corrected- to-normal vision." However, in most cases, there is no indication that visual acuity was actually measured, and it is likely that the investigators relied largely on self-reported visual status of subjects, which is often inaccurate. We investigated whether differences in visual acuity influence one of the most commonly observed findings in the event-related potentials literature on cognitive aging, a reduction in posterior P3b amplitude, which is an index of cognitive decision-making/updating. Well-matched young (n=26) and old adults (n=29) participated in a visual oddball task. Measured visual acuity with corrective lenses was worse in old than young adults. Results demonstrated that the robust age-related decline in P3b amplitude to visual targets disappeared after controlling for visual acuity, but was unaffected by accounting for auditory acuity. Path analysis confirmed that the relationship between age and diminished P3b to visual targets was mediated by visual acuity, suggesting that conveyance of suboptimal sensory data due to peripheral, rather than central, deficits may undermine subsequent neural processing. We conclude that until the relationship between age-associated differences in visual acuity and neural activity during experimental tasks is clearly established, investigators should exercise caution attributing results to differences in cognitive processing. PMID:26825439

  14. Visual Contextual Effects of Orientation, Contrast, Flicker, and Luminance: All Are Affected by Normal Aging

    PubMed Central

    Nguyen, Bao N.; McKendrick, Allison M.

    2016-01-01

    The perception of a visual stimulus can be markedly altered by spatial interactions between the stimulus and its surround. For example, a grating stimulus appears lower in contrast when surrounded by a similar pattern of higher contrast: a phenomenon known as surround suppression of perceived contrast. Such center–surround interactions in visual perception are numerous and arise from both cortical and pre-cortical neural circuitry. For example, perceptual surround suppression of luminance and flicker are predominantly mediated pre-cortically, whereas contrast and orientation suppression have strong cortical contributions. Here, we compare the perception of older and younger observers on a battery of tasks designed to assess such visual contextual effects. For all visual dimensions tested (luminance, flicker, contrast, and orientation), on average the older adults showed greater suppression of central targets than the younger adult group. The increase in suppression was consistent in magnitude across all tasks, suggesting that normal aging produces a generalized, non-specific alteration to contextual processing in vision. PMID:27148047

  15. Differential development of visual attention skills in school-age children

    PubMed Central

    Dye, Matthew W. G.; Bavelier, Daphne

    2009-01-01

    Children aged 7–17 years and adults aged 18–22 years were tested on three aspects of visual attention: the ability to distribute visual attention across the field to search for a target, the time required for attention to recover from being directed towards a target, and the number of objects to which attention can be simultaneously allocated. The data suggested different developmental trajectories for these components of visual attention within the same set of participants. This suggests that, to some extent, spatial, temporal and object-based attentional processes are subserved by different neural resources which develop at different rate. In addition, participants who played action games showed enhanced performance on all aspects of attention tested as compared to non-gamers. These findings reveal a potential facilitation of development of attentional skills in children who are avid players of action video games. As these games are predominantly drawing a male audience, young girls are at risk of underperforming on such tests, calling for a careful control of video game usage when assessing gender differences in attentional tasks. PMID:19836409

  16. Anterior Lamina Cribrosa Surface Depth, Age, and Visual Field Sensitivity in the Portland Progression Project

    PubMed Central

    Ren, Ruojin; Yang, Hongli; Gardiner, Stuart K.; Fortune, Brad; Hardin, Christy; Demirel, Shaban; Burgoyne, Claude F.

    2014-01-01

    Purpose. To assess the effect of age on spectral-domain optical coherence tomography (SDOCT)-detected lamina cribrosa depth while controlling for visual field (VF) status and retinal nerve fiber layer thickness (RNFLT) in 221 high-risk ocular hypertension and glaucoma patients enrolled in the Portland Progression Project. Methods. In this cross-sectional study, each participant underwent 870-nm SDOCT to obtain high-resolution radial B-scans centered on the optic nerve head (ONH) and a standardized ophthalmologic examination, including automated perimetry, on the same day. For each ONH, an anterior lamina cribrosa surface depth (ALCSD) parameter was generated as the average perpendicular distance from each anterior lamina cribrosa surface point relative to Bruch's membrane opening (BMO) reference plane within all 24 delineated B-scans. The relative effects of age, age-corrected VF status (mean deviation [MD]), and RNFLT on ALCSD were analyzed. Results. The mean age ± SD of participants was 64 ± 11 years (range, 33–90 years). The relationship between ALCSD and MD was age-dependent. ALCSD = 407.68 − 67.13 × MD − 0.08 × Age + 0.89 × MD × Age (MD, P = 0.001; MD × Age, P = 0.004). The relationship between ALCSD and RNFLT may also be age-dependent but did not achieve significance (interaction term, P = 0.067). ALCSD increased with worse VF status in younger eyes but not in older eyes. In older eyes, the anterior lamina was shallower than in younger eyes for the same VF status and RNFLT. Conclusions. These data are consistent with the concept that structure/structure and structure/function relationships change with age. PMID:24474264

  17. Effects of aging and sensory loss on glial cells in mouse visual and auditory cortices

    PubMed Central

    Tremblay, Marie-Ève; Zettel, Martha L.; Ison, James R.; Allen, Paul D.; Majewska, Ania K.

    2011-01-01

    Normal aging is often accompanied by a progressive loss of receptor sensitivity in hearing and vision, whose consequences on cellular function in cortical sensory areas have remained largely unknown. By examining the primary auditory (A1) and visual (V1) cortices in two inbred strains of mice undergoing either age-related loss of audition (C57BL/6J) or vision (CBA/CaJ), we were able to describe cellular and subcellular changes that were associated with normal aging (occurring in A1 and V1 of both strains) or specifically with age-related sensory loss (only in A1 of C57BL/6J or V1 of CBA/CaJ), using immunocytochemical electron microscopy and light microscopy. While the changes were subtle in neurons, glial cells and especially microglia were transformed in aged animals. Microglia became more numerous and irregularly distributed, displayed more variable cell body and process morphologies, occupied smaller territories, and accumulated phagocytic inclusions that often displayed ultrastructural features of synaptic elements. Additionally, evidence of myelination defects were observed, and aged oligodendrocytes became more numerous and were more often encountered in contiguous pairs. Most of these effects were profoundly exacerbated by age-related sensory loss. Together, our results suggest that the age-related alteration of glial cells in sensory cortical areas can be accelerated by activity-driven central mechanisms that result from an age-related loss of peripheral sensitivity. In light of our observations, these age-related changes in sensory function should be considered when investigating cellular, cortical and behavioral functions throughout the lifespan in these commonly used C57BL/6J and CBA/CaJ mouse models. PMID:22223464

  18. Synchronization trigger control system for flow visualization

    NASA Technical Reports Server (NTRS)

    Chun, K. S.

    1987-01-01

    The use of cinematography or holographic interferometry for dynamic flow visualization in an internal combustion engine requires a control device that globally synchronizes camera and light source timing at a predefined shaft encoder angle. The device is capable of 0.35 deg resolution for rotational speeds of up to 73 240 rpm. This was achieved by implementing the shaft encoder signal addressed look-up table (LUT) and appropriate latches. The developed digital signal processing technique achieves 25 nsec of high speed triggering angle detection by using direct parallel bit comparison of the shaft encoder digital code with a simulated angle reference code, instead of using angle value comparison which involves more complicated computation steps. In order to establish synchronization to an AC reference signal whose magnitude is variant with the rotating speed, a dynamic peak followup synchronization technique has been devised. This method scrutinizes the reference signal and provides the right timing within 40 nsec. Two application examples are described.

  19. Defining the cortical visual systems: "what", "where", and "how"

    NASA Technical Reports Server (NTRS)

    Creem, S. H.; Proffitt, D. R.; Kaiser, M. K. (Principal Investigator)

    2001-01-01

    The visual system historically has been defined as consisting of at least two broad subsystems subserving object and spatial vision. These visual processing streams have been organized both structurally as two distinct pathways in the brain, and functionally for the types of tasks that they mediate. The classic definition by Ungerleider and Mishkin labeled a ventral "what" stream to process object information and a dorsal "where" stream to process spatial information. More recently, Goodale and Milner redefined the two visual systems with a focus on the different ways in which visual information is transformed for different goals. They relabeled the dorsal stream as a "how" system for transforming visual information using an egocentric frame of reference in preparation for direct action. This paper reviews recent research from psychophysics, neurophysiology, neuropsychology and neuroimaging to define the roles of the ventral and dorsal visual processing streams. We discuss a possible solution that allows for both "where" and "how" systems that are functionally and structurally organized within the posterior parietal lobe.

  20. How Information Visualization Systems Change Users' Understandings of Complex Data

    ERIC Educational Resources Information Center

    Allendoerfer, Kenneth Robert

    2009-01-01

    User-centered evaluations of information systems often focus on the usability of the system rather its usefulness. This study examined how a using an interactive knowledge-domain visualization (KDV) system affected users' understanding of a domain. Interactive KDVs allow users to create graphical representations of domains that depict important…

  1. VISUAL SYSTEM DYSFUNCTION FOLLOWING ACUTE TRIMETHYLTIN EXPOSURE IN RATS

    EPA Science Inventory

    Trimethyltin (TMT) has been shown to produce damage in the limbic system and several other brain areas. To date, damage to sensory systems has not been reported. The present study investigated the integrity of the visual system following acute exposure to TMT. Rats were chronical...

  2. VisualEyes: a modular software system for oculomotor experimentation.

    PubMed

    Guo, Yi; Kim, Eun H; Kim, Eun; Alvarez, Tara; Alvarez, Tara L

    2011-01-01

    Eye movement studies have provided a strong foundation forming an understanding of how the brain acquires visual information in both the normal and dysfunctional brain.(1) However, development of a platform to stimulate and store eye movements can require substantial programming, time and costs. Many systems do not offer the flexibility to program numerous stimuli for a variety of experimental needs. However, the VisualEyes System has a flexible architecture, allowing the operator to choose any background and foreground stimulus, program one or two screens for tandem or opposing eye movements and stimulate the left and right eye independently. This system can significantly reduce the programming development time needed to conduct an oculomotor study. The VisualEyes System will be discussed in three parts: 1) the oculomotor recording device to acquire eye movement responses, 2) the VisualEyes software written in LabView, to generate an array of stimuli and store responses as text files and 3) offline data analysis. Eye movements can be recorded by several types of instrumentation such as: a limbus tracking system, a sclera search coil, or a video image system. Typical eye movement stimuli such as saccadic steps, vergent ramps and vergent steps with the corresponding responses will be shown. In this video report, we demonstrate the flexibility of a system to create numerous visual stimuli and record eye movements that can be utilized by basic scientists and clinicians to study healthy as well as clinical populations. PMID:21490568

  3. The Orbital Maneuvering Vehicle Training Facility visual system concept

    NASA Technical Reports Server (NTRS)

    Williams, Keith

    1989-01-01

    The purpose of the Orbital Maneuvering Vehicle (OMV) Training Facility (OTF) is to provide effective training for OMV pilots. A critical part of the training environment is the Visual System, which will simulate the video scenes produced by the OMV Closed-Circuit Television (CCTV) system. The simulation will include camera models, dynamic target models, moving appendages, and scene degradation due to the compression/decompression of video signal. Video system malfunctions will also be provided to ensure that the pilot is ready to meet all challenges the real-world might provide. One possible visual system configuration for the training facility that will meet existing requirements is described.

  4. Demonstration results of an automated visual inspection system tool

    NASA Astrophysics Data System (ADS)

    Maram, J.; Gutow, D.; Coleman, P.; Norman, A.

    1992-07-01

    The general design and operation of an automated system for the visual inspection of the Space Shuttle Main Engine (SSME) Main Combustion Chamber injector are described. The software has been developed, and the system, in its simplified implementation, has been used in laboratory tests and in an engine test stand evaluation installed in an SSME Technology Test Bed engine. Each of the system functions have been separately demonstrated in the engine test stand evaluation. Through the further development of software and hardware, automated visual inspection systems will be able to provide a more reliable database to improve safety and reliability in rocket engine operations at a greatly reduced expenditure in time and money.

  5. AGeS: A Software System for Microbial Genome Sequence Annotation

    PubMed Central

    Kumar, Kamal; Desai, Valmik; Cheng, Li; Khitrov, Maxim; Grover, Deepak; Satya, Ravi Vijaya; Yu, Chenggang; Zavaljevski, Nela; Reifman, Jaques

    2011-01-01

    Background The annotation of genomes from next-generation sequencing platforms needs to be rapid, high-throughput, and fully integrated and automated. Although a few Web-based annotation services have recently become available, they may not be the best solution for researchers that need to annotate a large number of genomes, possibly including proprietary data, and store them locally for further analysis. To address this need, we developed a standalone software application, the Annotation of microbial Genome Sequences (AGeS) system, which incorporates publicly available and in-house-developed bioinformatics tools and databases, many of which are parallelized for high-throughput performance. Methodology The AGeS system supports three main capabilities. The first is the storage of input contig sequences and the resulting annotation data in a central, customized database. The second is the annotation of microbial genomes using an integrated software pipeline, which first analyzes contigs from high-throughput sequencing by locating genomic regions that code for proteins, RNA, and other genomic elements through the Do-It-Yourself Annotation (DIYA) framework. The identified protein-coding regions are then functionally annotated using the in-house-developed Pipeline for Protein Annotation (PIPA). The third capability is the visualization of annotated sequences using GBrowse. To date, we have implemented these capabilities for bacterial genomes. AGeS was evaluated by comparing its genome annotations with those provided by three other methods. Our results indicate that the software tools integrated into AGeS provide annotations that are in general agreement with those provided by the compared methods. This is demonstrated by a >94% overlap in the number of identified genes, a significant number of identical annotated features, and a >90% agreement in enzyme function predictions. PMID:21408217

  6. Olfactory-visual congruence effects stable across ages: yellow is warmer when it is pleasantly lemony.

    PubMed

    Guerdoux, Estelle; Trouillet, Raphaël; Brouillet, Denis

    2014-07-01

    This study aimed to examine the age-related differences in the olfactory-visual cross-correspondences and the extent to which they are moderated by the odors pleasantness. Sixty participants aged from 20- to 75- years (young, middle-aged and older adults) performed a priming task to explore the influence of six olfactory primes (lemon, orange, rose, thyme, mint and fish) on the categorization (cool vs. warm) of six subsequent color targets (yellow, orange, pink, malachite green, grass-green, and blue-gray). We tested mixed effects models. Response times were regressed on covariates models using both fixed effects (Groups of age, olfactory Pleasantness and multimodal Condition) and cross-random effects (Subject, Color and Odor). The random effects coding for Odor (p < .001) and Color (p = .001) were significant. There was a significant interaction effect ( p= .004) between Condition × Pleasantness, but not with Groups of age. The compatibility effect (i.e., when odors and colors were congruent, the targets processing were facilitated) was as much enhanced as the olfactory primes were pleasant. Cross-correspondences between olfaction and vision may be robust in aging. They should be considered alongside spatiotemporal but also emotional congruency. PMID:24924850

  7. The emotional blink: adult age differences in visual attention to emotional information.

    PubMed

    Langley, Linda K; Rokke, Paul D; Stark, Atiana C; Saville, Alyson L; Allen, Jaryn L; Bagne, Angela G

    2008-12-01

    To assess age differences in attention-emotion interactions, the authors asked young adults (ages 18-33 years) and older adults (ages 60-80 years) to identify target words in a rapid serial visual presentation (RSVP) task. The second of two target words was neutral or emotional in content (positive in Experiment 1, negative in Experiment 2). In general, the ability to identify targets from a word stream declined with age. Age differences specific to the attentional blink were greatly reduced when baseline detection accuracy was equated between groups. With regard to emotion effects, older adults showed enhanced identification of both positive and negative words relative to neutral words, whereas young adults showed enhanced identification of positive words and reduced identification of negative words. Together these findings suggest that the nature of attention-emotion interactions changes with age, but there was little support for a motivational shift consistent with emotional regulation goals at an early stage of cognitive processing. PMID:19140657

  8. Grey matter connectivity within and between auditory, language and visual systems in prelingually deaf adolescents

    PubMed Central

    Li, Wenjing; Li, Jianhong; Wang, Zhenchang; Li, Yong; Liu, Zhaohui; Yan, Fei; Xian, Junfang; He, Huiguang

    2015-01-01

    Abstract Purpose: Previous studies have shown brain reorganizations after early deprivation of auditory sensory. However, changes of grey matter connectivity have not been investigated in prelingually deaf adolescents yet. In the present study, we aimed to investigate changes of grey matter connectivity within and between auditory, language and visual systems in prelingually deaf adolescents. Methods: We recruited 16 prelingually deaf adolescents and 16 age-and gender-matched normal controls, and extracted the grey matter volume as the structural characteristic from 14 regions of interest involved in auditory, language or visual processing to investigate the changes of grey matter connectivity within and between auditory, language and visual systems. Sparse inverse covariance estimation (SICE) was utilized to construct grey matter connectivity between these brain regions. Results: The results show that prelingually deaf adolescents present weaker grey matter connectivity within auditory and visual systems, and connectivity between language and visual systems declined. Notably, significantly increased brain connectivity was found between auditory and visual systems in prelingually deaf adolescents. Conclusions: Our results indicate “cross-modal” plasticity after deprivation of the auditory input in prelingually deaf adolescents, especially between auditory and visual systems. Besides, auditory deprivation and visual deficits might affect the connectivity pattern within language and visual systems in prelingually deaf adolescents. PMID:25698109

  9. The Relationship between Perceived Computer Competence and the Employment Outcomes of Transition-Aged Youths with Visual Impairments

    ERIC Educational Resources Information Center

    Zhou, Li; Smith, Derrick W.; Parker, Amy T.; Griffin-Shirley, Nora

    2013-01-01

    Introduction: The study reported here explored the relationship between the self-perceived computer competence and employment outcomes of transition-aged youths with visual impairments. Methods: Data on 200 in-school youths and 190 out-of-school youths with a primary disability of visual impairment were retrieved from the database of the first…

  10. Parsing Heterogeneity in Autism Spectrum Disorders: Visual Scanning of Dynamic Social Scenes in School-Aged Children

    ERIC Educational Resources Information Center

    Rice, Katherine; Moriuchi, Jennifer M.; Jones, Warren; Klin, Ami

    2012-01-01

    Objective: To examine patterns of variability in social visual engagement and their relationship to standardized measures of social disability in a heterogeneous sample of school-aged children with autism spectrum disorders (ASD). Method: Eye-tracking measures of visual fixation during free-viewing of dynamic social scenes were obtained for 109…

  11. Age-Related Declines in Early Sensory Memory: Identification of Rapid Auditory and Visual Stimulus Sequences

    PubMed Central

    Fogerty, Daniel; Humes, Larry E.; Busey, Thomas A.

    2016-01-01

    Age-related temporal-processing declines of rapidly presented sequences may involve contributions of sensory memory. This study investigated recall for rapidly presented auditory (vowel) and visual (letter) sequences presented at six different stimulus onset asynchronies (SOA) that spanned threshold SOAs for sequence identification. Younger, middle-aged, and older adults participated in all tasks. Results were investigated at both equivalent performance levels (i.e., SOA threshold) and at identical physical stimulus values (i.e., SOAs). For four-item sequences, results demonstrated best performance for the first and last items in the auditory sequences, but only the first item for visual sequences. For two-item sequences, adults identified the second vowel or letter significantly better than the first. Overall, when temporal-order performance was equated for each individual by testing at SOA thresholds, recall accuracy for each position across the age groups was highly similar. These results suggest that modality-specific processing declines of older adults primarily determine temporal-order performance for rapid sequences. However, there is some evidence for a second amodal processing decline in older adults related to early sensory memory for final items in a sequence. This selective deficit was observed particularly for longer sequence lengths and was not accounted for by temporal masking. PMID:27199737

  12. Stereoscopic Displays And The Human Dual Visual System

    NASA Astrophysics Data System (ADS)

    Clapp, Robert E.

    1986-05-01

    There is only one real world. We "see" that world as extending into three dimensions because we look at it with two visual systems and with two eyes. We are not presented with two "pictures" of the real world, but with two separate sets of inputs into two separate systems. The analog of the eye as a camera has been a constant problem in the visualization of the "seeing" process. Overcoming the persistence of such an approach is the first requirement in developing a true stereoscopic display system. The eye is a dynamic sensing apparatus and supplies the brain with visual inputs. The brain constructs the scene we "see", and is responsible for our perceptions of the visual world. The sensory inputs from the human dual visual system (Ambient - wide FOV, Focal - detail FOV) are combined with other body senses in this perceptual process. Indeed, other body senses, in some degree, direct and control where and at what our eyes look. This process of conceptualization of the "real" world as perceived by ourselves can be related only within limits to the "real" world as perceived by others.. This paper addresses the processes by which our minds (with sensor inputs) work to form our stereoscopic perceptual concepts of the world, real or simulated, and the advantages (and problems) caused by our egocentric reduction of those data inputs. Discussion and evaluation of stereoscopic display systems compares current and future display systems.

  13. Regulating Critical Period Plasticity: Insight from the Visual System to Fear Circuitry for Therapeutic Interventions

    PubMed Central

    Nabel, Elisa M.; Morishita, Hirofumi

    2013-01-01

    Early temporary windows of heightened brain plasticity called critical periods developmentally sculpt neural circuits and contribute to adult behavior. Regulatory mechanisms of visual cortex development – the preeminent model of experience-dependent critical period plasticity-actively limit adult plasticity and have proved fruitful therapeutic targets to reopen plasticity and rewire faulty visual system connections later in life. Interestingly, these molecular mechanisms have been implicated in the regulation of plasticity in other functions beyond vision. Applying mechanistic understandings of critical period plasticity in the visual cortex to fear circuitry may provide a conceptual framework for developing novel therapeutic tools to mitigate aberrant fear responses in post traumatic stress disorder. In this review, we turn to the model of experience-dependent visual plasticity to provide novel insights for the mechanisms regulating plasticity in the fear system. Fear circuitry, particularly fear memory erasure, also undergoes age-related changes in experience-dependent plasticity. We consider the contributions of molecular brakes that halt visual critical period plasticity to circuitry underlying fear memory erasure. A major molecular brake in the visual cortex, perineuronal net formation, recently has been identified in the development of fear systems that are resilient to fear memory erasure. The roles of other molecular brakes, myelin-related Nogo receptor signaling and Lynx family proteins – endogenous inhibitors for nicotinic acetylcholine receptor, are explored in the context of fear memory plasticity. Such fear plasticity regulators, including epigenetic effects, provide promising targets for therapeutic interventions. PMID:24273519

  14. Aging assessment for active fire protection systems

    SciTech Connect

    Ross, S.B.; Nowlen, S.P.; Tanaka, T.

    1995-06-01

    This study assessed the impact of aging on the performance and reliability of active fire protection systems including both fixed fire suppression and fixed fire detection systems. The experience base shows that most nuclear power plants have an aggressive maintenance and testing program and are finding degraded fire protection system components before a failure occurs. Also, from the data reviewed it is clear that the risk impact of fire protection system aging is low. However, it is assumed that a more aggressive maintenance and testing program involving preventive diagnostics may reduce the risk impact even further.

  15. Visual Debugging of Visualization Software: A Case Study for Particle Systems

    SciTech Connect

    Angel, Edward; Crossno, Patricia

    1999-07-12

    Visualization systems are complex dynamic software systems. Debugging such systems is difficult using conventional debuggers because the programmer must try to imagine the three-dimensional geometry based on a list of positions and attributes. In addition, the programmer must be able to mentally animate changes in those positions and attributes to grasp dynamic behaviors within the algorithm. In this paper we shall show that representing geometry, attributes, and relationships graphically permits visual pattern recognition skills to be applied to the debugging problem. The particular application is a particle system used for isosurface extraction from volumetric data. Coloring particles based on individual attributes is especially helpful when these colorings are viewed as animations over successive iterations in the program. Although we describe a particular application, the types of tools that we discuss can be applied to a variety of problems.

  16. Stereoscopy and the Human Visual System

    PubMed Central

    Banks, Martin S.; Read, Jenny C. A.; Allison, Robert S.; Watt, Simon J.

    2012-01-01

    Stereoscopic displays have become important for many applications, including operation of remote devices, medical imaging, surgery, scientific visualization, and computer-assisted design. But the most significant and exciting development is the incorporation of stereo technology into entertainment: specifically, cinema, television, and video games. In these applications for stereo, three-dimensional (3D) imagery should create a faithful impression of the 3D structure of the scene being portrayed. In addition, the viewer should be comfortable and not leave the experience with eye fatigue or a headache. Finally, the presentation of the stereo images should not create temporal artifacts like flicker or motion judder. This paper reviews current research on stereo human vision and how it informs us about how best to create and present stereo 3D imagery. The paper is divided into four parts: (1) getting the geometry right, (2) depth cue interactions in stereo 3D media, (3) focusing and fixating on stereo images, and (4) how temporal presentation protocols affect flicker, motion artifacts, and depth distortion. PMID:23144596

  17. [Auditory guidance systems for the visually impaired people].

    PubMed

    He, Jing; Nie, Min; Luo, Lan; Tong, Shanbao; Niu, Jinhai; Zhu, Yisheng

    2010-04-01

    Visually impaired people face many inconveniences because of the loss of vision. Therefore, scientists are trying to design various guidance systems for improving the lives of the blind. Based on sensory substitution, auditory guidance has become an interesting topic in the field of biomedical engineering. In this paper, we made a state-of-technique review of the auditory guidance system. Although there have been many technical challenges, the auditory guidance system would be a useful alternative for the visually impaired people. PMID:20481341

  18. Visual Cues for an Adaptive Expert System.

    ERIC Educational Resources Information Center

    Miller, Helen B.

    NCR (National Cash Register) Corporation is pursuing opportunities to make their point of sale (POS) terminals easy to use and easy to learn. To approach the goal of making the technology invisible to the user, NCR has developed an adaptive expert prototype system for a department store POS operation. The structure for the adaptive system, the…

  19. Automatic visual inspection system for microelectronics

    NASA Technical Reports Server (NTRS)

    Micka, E. Z. (Inventor)

    1975-01-01

    A system for automatically inspecting an integrated circuit was developed. A device for shining a scanning narrow light beam at an integrated circuit to be inspected and another light beam at an accepted integrated circuit was included. A pair of photodetectors that receive light reflected from these integrated circuits, and a comparing system compares the outputs of the photodetectors.

  20. Retinal waves coordinate patterned activity throughout the developing visual system

    PubMed Central

    Ackman, James B.; Burbridge, Timothy J.; Crair, Michael C.

    2014-01-01

    Summary The morphologic and functional development of the vertebrate nervous system is initially governed by genetic factors and subsequently refined by neuronal activity. However, fundamental features of the nervous system emerge before sensory experience is possible. Thus, activity-dependent development occurring before the onset of experience must be driven by spontaneous activity, but the origin and nature of activity in vivo remains largely untested. Here we use optical methods to demonstrate in live neonatal mice that waves of spontaneous retinal activity are present and propagate throughout the entire visual system before eye opening. This patterned activity encompassed the visual field, relied on cholinergic neurotransmission, preferentially initiated in the binocular retina, and exhibited spatiotemporal correlations between the two hemispheres. Retinal waves were the primary source of activity in the midbrain and primary visual cortex, but only modulated ongoing activity in secondary visual areas. Thus, spontaneous retinal activity is transmitted through the entire visual system and carries patterned information capable of guiding the activity-dependent development of complex intra- and inter- hemispheric circuits before the onset of vision. PMID:23060192

  1. The Drosophila larval visual system: high-resolution analysis of a simple visual neuropil.

    PubMed

    Sprecher, Simon G; Cardona, Albert; Hartenstein, Volker

    2011-10-01

    The task of the visual system is to translate light into neuronal encoded information. This translation of photons into neuronal signals is achieved by photoreceptor neurons (PRs), specialized sensory neurons, located in the eye. Upon perception of light the PRs will send a signal to target neurons, which represent a first station of visual processing. Increasing complexity of visual processing stems from the number of distinct PR subtypes and their various types of target neurons that are contacted. The visual system of the fruit fly larva represents a simple visual system (larval optic neuropil, LON) that consists of 12 PRs falling into two classes: blue-senstive PRs expressing Rhodopsin 5 (Rh5) and green-sensitive PRs expressing Rhodopsin 6 (Rh6). These afferents contact a small number of target neurons, including optic lobe pioneers (OLPs) and lateral clock neurons (LNs). We combine the use of genetic markers to label both PR subtypes and the distinct, identifiable sets of target neurons with a serial EM reconstruction to generate a high-resolution map of the larval optic neuropil. We find that the larval optic neuropil shows a clear bipartite organization consisting of one domain innervated by PRs and one devoid of PR axons. The topology of PR projections, in particular the relationship between Rh5 and Rh6 afferents, is maintained from the nerve entering the brain to the axon terminals. The target neurons can be subdivided according to neurotransmitter or neuropeptide they use as well as the location within the brain. We further track the larval optic neuropil through development from first larval instar to its location in the adult brain as the accessory medulla. PMID:21781960

  2. The Drosophila larval visual system: high-resolution analysis of a simple visual neuropil

    PubMed Central

    Sprecher, Simon G.; Cardona, Albert; Hartenstein, Volker

    2012-01-01

    The task of the visual system is to translate light into neuronal encoded information. This translation of photons into neuronal signals is achieved by photoreceptor neurons (PRs), specialized sensory neurons, located in the eye. Upon perception of light the PRs will send a signal to target neurons, which represent a first station of visual processing. Increasing complexity of visual processing stems from the number of distinct PR-subtypes and their various types of target neurons that are contacted. The visual system of the fruit fly larva represents a simple visual system (larval optic neuropil, LON) that consists of 12 PRs falling into two classes: blue-senstive PRs expressing Rhodopsin 5 (Rh5) and green-sensitive PRs expressing Rhodopsin 6 (Rh6). These afferents contact a small number of target neurons, including optic lobe pioneers (OLPs) and lateral clock neurons (LNs). We combine the use of genetic markers to label both PR-subtypes and the distinct, identifiable sets of target neurons with a serial EM reconstruction to generate a high-resolution map of the larval optic neuropil. We find that the larval optic neuropil shows a clear bipartite organization consisting of one domain innervated by PRs and one devoid of PR axons. The topology of PR projections, in particular the relationship between Rh5 and Rh6 afferents, is maintained from the nerve entering the brain to the axon terminals. The target neurons can be subdivided according to neurotransmitter or neuropeptide they use as well as the location within the brain. We further track the larval optic neuropil through development from first larval instar to its location in the adult brain as the accessory medulla. PMID:21781960

  3. Effects of Aging on the Respiratory System.

    ERIC Educational Resources Information Center

    Levitzky, Michael G.

    1984-01-01

    Relates alterations in respiratory system functions occurring with aging to changes in respiratory system structure during the course of life. Main alterations noted include loss of alveolar elastic recoil, alteration in chest wall structure and decreased respiratory muscle strength, and loss of surface area and changes in pulmonary circulation.…

  4. Ageing and feature binding in visual working memory: The role of presentation time.

    PubMed

    Rhodes, Stephen; Parra, Mario A; Logie, Robert H

    2016-01-01

    A large body of research has clearly demonstrated that healthy ageing is accompanied by an associative memory deficit. Older adults exhibit disproportionately poor performance on memory tasks requiring the retention of associations between items (e.g., pairs of unrelated words). In contrast to this robust deficit, older adults' ability to form and temporarily hold bound representations of an object's surface features, such as colour and shape, appears to be relatively well preserved. However, the findings of one set of experiments suggest that older adults may struggle to form temporary bound representations in visual working memory when given more time to study objects. However, these findings were based on between-participant comparisons across experimental paradigms. The present study directly assesses the role of presentation time in the ability of younger and older adults to bind shape and colour in visual working memory using a within-participant design. We report new evidence that giving older adults longer to study memory objects does not differentially affect their immediate memory for feature combinations relative to individual features. This is in line with a growing body of research suggesting that there is no age-related impairment in immediate memory for colour-shape binding. PMID:25993530

  5. Visual Systems for Remotely Controlled Vehicles

    NASA Technical Reports Server (NTRS)

    Rezek, T.

    1984-01-01

    The Variable Acuity Remote Viewing System is discussed. It was conceived as a technique for resolving the field of view/resolution/ bandwidth tradeoffs that exist in remote viewing systems. This system is based on the fact that integration of the human eye acuity function shows only about 130,000 pixels are required to fully support the human vision. This quantity is well within the capabilities of conventional video systems. The technique utilizes a non-linear optical system in both the sensing and display equipment. The non-linearity is achieved by a special lens which translates a uniform pixel array on its image plane into the object field as a variable angular array. This lens will record the same angular detail the eye would see when viewing the same scene and compress this detail into a uniform matrix of equal sized picture elements on its image plane. This image can be scanned with a broadcast quality tv having a 525 line raster scan. Conventional transmission equipment can then also be used to send the image information to a remote location. When received, the image is projected by a light valve projector onto a hemispherical screen by an identical non-linear lens.

  6. Expression of UNC-5 in the developing Xenopus visual system.

    PubMed

    Anderson, Richard B; Holt, Christine E

    2002-10-01

    Netrin-1 and its receptors deleted in colorectal cancer (DCC) and neogenin are expressed within the developing visual system and have been implicated in mediating axon guidance and cell migration. However, the expression of the netrin-1 receptor UNC-5 has not yet been addressed. Here we clone Xenopus UNC-5 (XUNC-5) and describe its expression within the developing visual system. Xunc-5 transcripts are expressed within the developing optic vesicles and later become restricted to the dorsal ciliary marginal zone, a site of retinoblast proliferation and differentiation. This highly restricted expression pattern could make XUNC-5 an excellent marker of dorsal retinal precursor cells. PMID:12351179

  7. The Scalable Reasoning System: Lightweight Visualization for Distributed Analytics

    SciTech Connect

    Pike, William A.; Bruce, Joseph R.; Baddeley, Robert L.; Best, Daniel M.; Franklin, Lyndsey; May, Richard A.; Rice, Douglas M.; Riensche, Roderick M.; Younkin, Katarina

    2008-11-01

    A central challenge in visual analytics is the creation of accessible, widely distributable analysis applications that bring the benefits of visual discovery to as broad a user base as possible. Moreover, to support the role of visualization in the knowledge creation process, it is advantageous to allow users to describe the reasoning strategies they employ while interacting with analytic environments. We introduce an application suite called the Scalable Reasoning System (SRS), which provides web-based and mobile interfaces for visual analysis. The service-oriented analytic framework that underlies SRS provides a platform for deploying pervasive visual analytic environments across an enterprise. SRS represents a “lightweight” approach to visual analytics whereby thin client analytic applications can be rapidly deployed in a platform-agnostic fashion. Client applications support multiple coordinated views while giving analysts the ability to record evidence, assumptions, hypotheses and other reasoning artifacts. We describe the capabilities of SRS in the context of a real-world deployment at a regional law enforcement organization.

  8. The Scalable Reasoning System: Lightweight Visualization for Distributed Analytics

    SciTech Connect

    Pike, William A.; Bruce, Joseph R.; Baddeley, Robert L.; Best, Daniel M.; Franklin, Lyndsey; May, Richard A.; Rice, Douglas M.; Riensche, Roderick M.; Younkin, Katarina

    2009-03-01

    A central challenge in visual analytics is the creation of accessible, widely distributable analysis applications that bring the benefits of visual discovery to as broad a user base as possible. Moreover, to support the role of visualization in the knowledge creation process, it is advantageous to allow users to describe the reasoning strategies they employ while interacting with analytic environments. We introduce an application suite called the Scalable Reasoning System (SRS), which provides web-based and mobile interfaces for visual analysis. The service-oriented analytic framework that underlies SRS provides a platform for deploying pervasive visual analytic environments across an enterprise. SRS represents a “lightweight” approach to visual analytics whereby thin client analytic applications can be rapidly deployed in a platform-agnostic fashion. Client applications support multiple coordinated views while giving analysts the ability to record evidence, assumptions, hypotheses and other reasoning artifacts. We describe the capabilities of SRS in the context of a real-world deployment at a regional law enforcement organization.

  9. Satellite Imagery Assisted Road-Based Visual Navigation System

    NASA Astrophysics Data System (ADS)

    Volkova, A.; Gibbens, P. W.

    2016-06-01

    There is a growing demand for unmanned aerial systems as autonomous surveillance, exploration and remote sensing solutions. Among the key concerns for robust operation of these systems is the need to reliably navigate the environment without reliance on global navigation satellite system (GNSS). This is of particular concern in Defence circles, but is also a major safety issue for commercial operations. In these circumstances, the aircraft needs to navigate relying only on information from on-board passive sensors such as digital cameras. An autonomous feature-based visual system presented in this work offers a novel integral approach to the modelling and registration of visual features that responds to the specific needs of the navigation system. It detects visual features from Google Earth* build a feature database. The same algorithm then detects features in an on-board cameras video stream. On one level this serves to localise the vehicle relative to the environment using Simultaneous Localisation and Mapping (SLAM). On a second level it correlates them with the database to localise the vehicle with respect to the inertial frame. The performance of the presented visual navigation system was compared using the satellite imagery from different years. Based on comparison results, an analysis of the effects of seasonal, structural and qualitative changes of the imagery source on the performance of the navigation algorithm is presented. * The algorithm is independent of the source of satellite imagery and another provider can be used

  10. Large-scale organization of the primate cortical visual system

    NASA Astrophysics Data System (ADS)

    Young, Malcolm P.

    1994-03-01

    The primate cortical visual system is composed of many structurally and functionally distinct areas or processing compartments, each of which receives on average about ten afferent inputs from other cortical areas and sends about the same number of output projections. The visual cortex is thus served by a very large number of cortico-cortical connections, so that the areas and their interconnections form a network of remarkable complexity. The gross organization of this cortical processing system hence represents a formidable topological problem: while the spatial position of the areas in the brain are becoming fairly well established, the gross `processing architecture,' defined by the connections, is much less well understood. I have applied optimization analysis to connectional data on the cortical visual system to address this topological problem. This approach gives qualitative and quantitative insight into the connectional topology of the primate cortical visual system and provides new evidence supporting suggestions that the system is divided into a dorsal `stream' and a ventral `stream' with limited cross-talk, that these two streams reconverge in the region of the principal sulcus (area 46) and in the superior temporal polysensory areas, that the system is hierarchically organized, and that the majority of the connections are from nearest-neighbor and next-door- but-one areas. The robustness of the results is shown by reanalyzing the connection data after various manipulations that simulate gross changes to the neuroanatomical database.

  11. Visuals and Visualisation of Human Body Systems

    ERIC Educational Resources Information Center

    Mathai, Sindhu; Ramadas, Jayashree

    2009-01-01

    This paper explores the role of diagrams and text in middle school students' understanding and visualisation of human body systems. We develop a common framework based on structure and function to assess students' responses across diagram and verbal modes. Visualisation is defined in terms of understanding transformations on structure and relating…

  12. Negotiated control between the manual and visual systems for visually guided hand reaching movements

    PubMed Central

    2014-01-01

    Background Control of reaching movements for manual work, vehicle operation, or interactions with manual interfaces requires concurrent gaze control for visual guidance of the hand. We hypothesize that reaching movements are based on negotiated strategies to resolve possible conflicting demands placed on body segments shared by the visual (gaze) and manual (hand) control systems. Further, we hypothesize that a multiplicity of possible spatial configurations (redundancy) in a movement system enables a resolution of conflicting demands that does not require sacrificing the goals of the two systems. Methods The simultaneous control of manual reach and gaze during seated reaching movements was simulated by solving an inverse kinematics model wherein joint trajectories were estimated from a set of recorded hand and head movements. A secondary objective function, termed negotiation function, was introduced to describe a means for the manual reach and gaze directing systems to balance independent goals against (possibly competing) demands for shared resources, namely the torso movement. For both systems, the trade-off may be resolved without sacrificing goal achievement by taking advantage of redundant degrees of freedom. Estimated joint trajectories were then compared to joint movement recordings from ten participants. Joint angles were predicted with and without the negotiation function in place, and model accuracy was determined using the root-mean-square errors (RMSEs) and differences between estimated and recorded joint angles. Results The prediction accuracy was generally improved when negotiation was included: the negotiated control reduced RMSE by 16% and 30% on average when compared to the systems with only manual or visual control, respectively. Furthermore, the RMSE in the negotiated control system tended to improve with torso movement amplitude. Conclusions The proposed model describes how multiple systems cooperate to perform goal-directed human movements

  13. A visually guided collision warning system with a neuromorphic architecture.

    PubMed

    Okuno, Hirotsugu; Yagi, Tetsuya

    2008-12-01

    We have designed a visually guided collision warning system with a neuromorphic architecture, employing an algorithm inspired by the visual nervous system of locusts. The system was implemented with mixed analog-digital integrated circuits consisting of an analog resistive network and field-programmable gate array (FPGA) circuits. The resistive network processes the interaction between the laterally spreading excitatory and inhibitory signals instantaneously, which is essential for real-time computation of collision avoidance with a low power consumption and a compact hardware. The system responded selectively to approaching objects of simulated movie images at close range. The system was, however, confronted with serious noise problems due to the vibratory ego-motion, when it was installed in a mobile miniature car. To overcome this problem, we developed the algorithm, which is also installable in FPGA circuits, in order for the system to respond robustly during the ego-motion. PMID:19028077

  14. Impact of Age and Myopia on the Rate of Visual Field Progression in Glaucoma Patients.

    PubMed

    Park, Hae-Young Lopilly; Hong, Kyung Euy; Park, Chan Kee

    2016-05-01

    Myopia is rapidly increasing in young populations and patients with glaucoma associated with myopia are reported to be young aged in East Asia. These young patients have a longer life expectancy, which increases their risk of end-of-life visual disabilities. There is a need to understand the clinical course of myopic glaucoma patients, which may be important for the care of these myopic populations. In this study, we evaluated the relationship between the age at presentation and the rate of glaucoma progression in the visual field (VF) according to the presence of myopia. The study was conducted as a prospective observational study including 179 patients with open-angle glaucoma who had undergone at least 5 VF examinations with a follow-up of at least 5 years. The progression rate of the mean deviation (MD) and the pattern standard deviation (PSD) are expressed as change in decibels (dB) per year. The slopes of the MD and PSD were calculated by linear regression analyses. Factors related to the slope of VF MD changes were analyzed with correlation and regression analyses. The slope of the linear fit line plotted against age at presentation and the rate of change in the VF MD was -0.026 (P < 0.001) in the myopic group and -0.008 (P = 0.167) in the nonmyopic group; the relationship was more prominent in the myopic group than the nonmyopic group. In the myopic group, age (β = -0.417; 95% confidence intervals (CI), -0.651 to -0.200; P = 0.050) and baseline untreated intraocular pressure (β = -0.179; 95% CI, -0.331 to -0.028; P = 0.022) were significantly related to the rate of change in the MD, which was only the presence of disc hemorrhage (β = -0.335; 95% CI, -0.568 to -0.018; P = 0.022) in the nonmyopic group. Age at presentation was significantly related to the rate of change in the VF in glaucomatous eyes with myopia compared to eyes without myopia. Older age was significantly related to the rate of change in the VF only in

  15. Impact of Age and Myopia on the Rate of Visual Field Progression in Glaucoma Patients

    PubMed Central

    Park, Hae-Young Lopilly; Hong, Kyung Euy; Park, Chan Kee

    2016-01-01

    Abstract Myopia is rapidly increasing in young populations and patients with glaucoma associated with myopia are reported to be young aged in East Asia. These young patients have a longer life expectancy, which increases their risk of end-of-life visual disabilities. There is a need to understand the clinical course of myopic glaucoma patients, which may be important for the care of these myopic populations. In this study, we evaluated the relationship between the age at presentation and the rate of glaucoma progression in the visual field (VF) according to the presence of myopia. The study was conducted as a prospective observational study including 179 patients with open-angle glaucoma who had undergone at least 5 VF examinations with a follow-up of at least 5 years. The progression rate of the mean deviation (MD) and the pattern standard deviation (PSD) are expressed as change in decibels (dB) per year. The slopes of the MD and PSD were calculated by linear regression analyses. Factors related to the slope of VF MD changes were analyzed with correlation and regression analyses. The slope of the linear fit line plotted against age at presentation and the rate of change in the VF MD was −0.026 (P < 0.001) in the myopic group and −0.008 (P = 0.167) in the nonmyopic group; the relationship was more prominent in the myopic group than the nonmyopic group. In the myopic group, age (β = −0.417; 95% confidence intervals (CI), −0.651 to −0.200; P = 0.050) and baseline untreated intraocular pressure (β = −0.179; 95% CI, −0.331 to −0.028; P = 0.022) were significantly related to the rate of change in the MD, which was only the presence of disc hemorrhage (β = −0.335; 95% CI, −0.568 to −0.018; P = 0.022) in the nonmyopic group. Age at presentation was significantly related to the rate of change in the VF in glaucomatous eyes with myopia compared to eyes without myopia. Older age was significantly related to the rate of

  16. Age-Related Visual and Kinesthetic Encoding Effects on Spatial Memory of a Maze-Like Floor Plan.

    ERIC Educational Resources Information Center

    Sinnott, Jan D.; And Others

    As part of an experimental research program on lifespan naturalistic and laboratory memory for spatial representation, investigators examined interactions between the effects of visual and kinesthetic encoding and age on memory for space using a modification of the Sinnott (1987) human maze paradigm. It was hypothesized that an age effect favoring…

  17. Age-Related Occipito-Temporal Hypoactivation during Visual Search: Relationships between mN2pc Sources and Performance

    ERIC Educational Resources Information Center

    Lorenzo-Lopez, L.; Gutierrez, R.; Moratti, S.; Maestu, F.; Cadaveira, F.; Amenedo, E.

    2011-01-01

    Recently, an event-related potential (ERP) study (Lorenzo-Lopez et al., 2008) provided evidence that normal aging significantly delays and attenuates the electrophysiological correlate of the allocation of visuospatial attention (N2pc component) during a feature-detection visual search task. To further explore the effects of normal aging on the…

  18. New apparatus of single particle trap system for aerosol visualization

    NASA Astrophysics Data System (ADS)

    Higashi, Hidenori; Fujioka, Tomomi; Endo, Tetsuo; Kitayama, Chiho; Seto, Takafumi; Otani, Yoshio

    2014-08-01

    Control of transport and deposition of charged aerosol particles is important in various manufacturing processes. Aerosol visualization is an effective method to directly observe light scattering signal from laser-irradiated single aerosol particle trapped in a visualization cell. New single particle trap system triggered by light scattering pulse signal was developed in this study. The performance of the device was evaluated experimentally. Experimental setup consisted of an aerosol generator, a differential mobility analyzer (DMA), an optical particle counter (OPC) and the single particle trap system. Polystylene latex standard (PSL) particles (0.5, 1.0 and 2.0 μm) were generated and classified according to the charge by the DMA. Singly charged 0.5 and 1.0 μm particles and doubly charged 2.0 μm particles were used as test particles. The single particle trap system was composed of a light scattering signal detector and a visualization cell. When the particle passed through the detector, trigger signal with a given delay time sent to the solenoid valves upstream and downstream of the visualization cell for trapping the particle in the visualization cell. The motion of particle in the visualization cell was monitored by CCD camera and the gravitational settling velocity and the electrostatic migration velocity were measured from the video image. The aerodynamic diameter obtained from the settling velocity was in good agreement with Stokes diameter calculated from the electrostatic migration velocity for individual particles. It was also found that the aerodynamic diameter obtained from the settling velocity was a one-to-one function of the scattered light intensity of individual particles. The applicability of this system will be discussed.

  19. Living Color Frame System: PC graphics tool for data visualization

    NASA Technical Reports Server (NTRS)

    Truong, Long V.

    1993-01-01

    Living Color Frame System (LCFS) is a personal computer software tool for generating real-time graphics applications. It is highly applicable for a wide range of data visualization in virtual environment applications. Engineers often use computer graphics to enhance the interpretation of data under observation. These graphics become more complicated when 'run time' animations are required, such as found in many typical modern artificial intelligence and expert systems. Living Color Frame System solves many of these real-time graphics problems.

  20. A prototype system based on visual interactive SDM called VGC

    NASA Astrophysics Data System (ADS)

    Jia, Zelu; Liu, Yaolin; Liu, Yanfang

    2009-10-01

    In many application domains, data is collected and referenced by its geo-spatial location. Spatial data mining, or the discovery of interesting patterns in such databases, is an important capability in the development of database systems. Spatial data mining recently emerges from a number of real applications, such as real-estate marketing, urban planning, weather forecasting, medical image analysis, road traffic accident analysis, etc. It demands for efficient solutions for many new, expensive, and complicated problems. For spatial data mining of large data sets to be effective, it is also important to include humans in the data exploration process and combine their flexibility, creativity, and general knowledge with the enormous storage capacity and computational power of today's computers. Visual spatial data mining applies human visual perception to the exploration of large data sets. Presenting data in an interactive, graphical form often fosters new insights, encouraging the information and validation of new hypotheses to the end of better problem-solving and gaining deeper domain knowledge. In this paper a visual interactive spatial data mining prototype system (visual geo-classify) based on VC++6.0 and MapObject2.0 are designed and developed, the basic algorithms of the spatial data mining is used decision tree and Bayesian networks, and data classify are used training and learning and the integration of the two to realize. The result indicates it's a practical and extensible visual interactive spatial data mining tool.

  1. Visualizing Terrestrial and Aquatic Systems in 3D - in IEEE VisWeek 2014

    EPA Science Inventory

    The need for better visualization tools for environmental science is well documented, and the Visualization for Terrestrial and Aquatic Systems project (VISTAS) aims to both help scientists produce effective environmental science visualizations and to determine which visualizatio...

  2. Structural and Functional Brain Changes beyond Visual System in Patients with Advanced Glaucoma

    PubMed Central

    Motolese, Ilaria; De Leucio, Alessandro; Iester, Michele; Motolese, Eduardo; Federico, Antonio; De Stefano, Nicola

    2014-01-01

    In order to test the hypothesis that in primary open angle glaucoma (POAG), an important cause of irreversible blindness, a spreading of neurodegeneration occurs through the brain, we performed multimodal MRI and subsequent whole-brain explorative voxelwise analyses in 13 advanced POAG patients and 12 age-matched normal controls (NC). Altered integrity (decreased fractional anisotropy or increased diffusivities) of white matter (WM) tracts was found not only along the visual pathway of POAG but also in nonvisual WM tracts (superior longitudinal fascicle, anterior thalamic radiation, corticospinal tract, middle cerebellar peduncle). POAG patients also showed brain atrophy in both visual cortex and other distant grey matter (GM) regions (frontoparietal cortex, hippocampi and cerebellar cortex), decreased functional connectivity (FC) in visual, working memory and dorsal attention networks and increased FC in visual and executive networks. In POAG, abnormalities in structure and FC within and outside visual system correlated with visual field parameters in the poorer performing eyes, thus emphasizing their clinical relevance. Altogether, this represents evidence that a vision disorder such as POAG can be considered a widespread neurodegenerative condition. PMID:25162716

  3. A simpler primate brain: the visual system of the marmoset monkey

    PubMed Central

    Solomon, Samuel G.; Rosa, Marcello G. P.

    2014-01-01

    Humans are diurnal primates with high visual acuity at the center of gaze. Although primates share many similarities in the organization of their visual centers with other mammals, and even other species of vertebrates, their visual pathways also show unique features, particularly with respect to the organization of the cerebral cortex. Therefore, in order to understand some aspects of human visual function, we need to study non-human primate brains. Which species is the most appropriate model? Macaque monkeys, the most widely used non-human primates, are not an optimal choice in many practical respects. For example, much of the macaque cerebral cortex is buried within sulci, and is therefore inaccessible to many imaging techniques, and the postnatal development and lifespan of macaques are prohibitively long for many studies of brain maturation, plasticity, and aging. In these and several other respects the marmoset, a small New World monkey, represents a more appropriate choice. Here we review the visual pathways of the marmoset, highlighting recent work that brings these advantages into focus, and identify where additional work needs to be done to link marmoset brain organization to that of macaques and humans. We will argue that the marmoset monkey provides a good subject for studies of a complex visual system, which will likely allow an important bridge linking experiments in animal models to humans. PMID:25152716

  4. ATS displays: A reasoning visualization tool for expert systems

    NASA Technical Reports Server (NTRS)

    Selig, William John; Johannes, James D.

    1990-01-01

    Reasoning visualization is a useful tool that can help users better understand the inherently non-sequential logic of an expert system. While this is desirable in most all expert system applications, it is especially so for such critical systems as those destined for space-based operations. A hierarchical view of the expert system reasoning process and some characteristics of these various levels is presented. Also presented are Abstract Time Slice (ATS) displays, a tool to visualize the plethora of interrelated information available at the host inferencing language level of reasoning. The usefulness of this tool is illustrated with some examples from a prototype potable water expert system for possible use aboard Space Station Freedom.

  5. Audio-Visual Perception System for a Humanoid Robotic Head

    PubMed Central

    Viciana-Abad, Raquel; Marfil, Rebeca; Perez-Lorenzo, Jose M.; Bandera, Juan P.; Romero-Garces, Adrian; Reche-Lopez, Pedro

    2014-01-01

    One of the main issues within the field of social robotics is to endow robots with the ability to direct attention to people with whom they are interacting. Different approaches follow bio-inspired mechanisms, merging audio and visual cues to localize a person using multiple sensors. However, most of these fusion mechanisms have been used in fixed systems, such as those used in video-conference rooms, and thus, they may incur difficulties when constrained to the sensors with which a robot can be equipped. Besides, within the scope of interactive autonomous robots, there is a lack in terms of evaluating the benefits of audio-visual attention mechanisms, compared to only audio or visual approaches, in real scenarios. Most of the tests conducted have been within controlled environments, at short distances and/or with off-line performance measurements. With the goal of demonstrating the benefit of fusing sensory information with a Bayes inference for interactive robotics, this paper presents a system for localizing a person by processing visual and audio data. Moreover, the performance of this system is evaluated and compared via considering the technical limitations of unimodal systems. The experiments show the promise of the proposed approach for the proactive detection and tracking of speakers in a human-robot interactive framework. PMID:24878593

  6. Visual-Tutorial System for Teaching Media Utilization.

    ERIC Educational Resources Information Center

    Butler, Lucius

    1979-01-01

    Discusses a self-instructional programed Visual-Tutorial learning system, designed to teach preservice elementary school teachers both theory and skills related to effective classroom utilization of audiovisual materials and equipment. An outline of the course, "Media Practicum," is included. (RAO)

  7. Aural Study Systems for the Visually Handicapped. Final Report.

    ERIC Educational Resources Information Center

    Nolan, Carson Y.; Morris, June E.

    Presented is the final report on development of an aural study system which involved approximately 1000 visually handicapped elementary, secondary, and college students. Given is background information such as the relative effectiveness of reading and listening during study, and factors that affect listening comprehension such as learner…

  8. Audio-visual perception system for a humanoid robotic head.

    PubMed

    Viciana-Abad, Raquel; Marfil, Rebeca; Perez-Lorenzo, Jose M; Bandera, Juan P; Romero-Garces, Adrian; Reche-Lopez, Pedro

    2014-01-01

    One of the main issues within the field of social robotics is to endow robots with the ability to direct attention to people with whom they are interacting. Different approaches follow bio-inspired mechanisms, merging audio and visual cues to localize a person using multiple sensors. However, most of these fusion mechanisms have been used in fixed systems, such as those used in video-conference rooms, and thus, they may incur difficulties when constrained to the sensors with which a robot can be equipped. Besides, within the scope of interactive autonomous robots, there is a lack in terms of evaluating the benefits of audio-visual attention mechanisms, compared to only audio or visual approaches, in real scenarios. Most of the tests conducted have been within controlled environments, at short distances and/or with off-line performance measurements. With the goal of demonstrating the benefit of fusing sensory information with a Bayes inference for interactive robotics, this paper presents a system for localizing a person by processing visual and audio data. Moreover, the performance of this system is evaluated and compared via considering the technical limitations of unimodal systems. The experiments show the promise of the proposed approach for the proactive detection and tracking of speakers in a human-robot interactive framework. PMID:24878593

  9. A Computerized System for Workplace Design for Visually Impaired Workers.

    ERIC Educational Resources Information Center

    Chen, J-G; Hou, C-A

    1991-01-01

    VITAL (Vision Impaired Task and Assignment Lexicon) is an integrated computerized system that performs workplace design tasks for visually impaired workers. VITAL consists of three modules: ergonomics consultation, disability index, and work measurement. Evaluation indicated that VITAL could be used as a tool to help nonprofessional vocational…

  10. SENTINEL: A Multiple Engine Information Retrieval and Visualization System.

    ERIC Educational Resources Information Center

    Fox, Kevin L.; Frieder, Ophir; Knepper, Margaret M.; Snowberg, Eric J.

    1999-01-01

    Describes SENTINEL, a prototype information-retrieval system that is a fusion of multiple information-retrieval technologies, integrating n-grams, a vector space model, and a neural network training rule. Discusses three-dimensional visualization capability, precision and recall, mathematical representation of a document, query building, and…