WorldWideScience

Sample records for subjects accessed visualizing

  1. The Problem of Subject Access to Visual Materials

    Directory of Open Access Journals (Sweden)

    Heather P. Jespersen

    2004-09-01

    Full Text Available This article discusses the problem of giving subject access to works of art. We survey both concept-based and content-based access by computers and by indexers/catalogers respectively, as well as issues of interoperability, database and indexer consistency, and cataloging standards. The authors, both of whom are trained art historians, question attempts to mystify fine art subject matter by the creation of clever library science systems that are executed by the naive. Only when trained art historians and knowledgeable catalogers are finally responsible for providing subject access to works of art, will true interoperability and consistency happen.

  2. Image size invariant visual cryptography for general access structures subject to display quality constraints.

    Science.gov (United States)

    Lee, Kai-Hui; Chiu, Pei-Ling

    2013-10-01

    Conventional visual cryptography (VC) suffers from a pixel-expansion problem, or an uncontrollable display quality problem for recovered images, and lacks a general approach to construct visual secret sharing schemes for general access structures. We propose a general and systematic approach to address these issues without sophisticated codebook design. This approach can be used for binary secret images in non-computer-aided decryption environments. To avoid pixel expansion, we design a set of column vectors to encrypt secret pixels rather than using the conventional VC-based approach. We begin by formulating a mathematic model for the VC construction problem to find the column vectors for the optimal VC construction, after which we develop a simulated-annealing-based algorithm to solve the problem. The experimental results show that the display quality of the recovered image is superior to that of previous papers.

  3. Ergonomics and accessibility for people with visual impairment in hotels.

    Science.gov (United States)

    Dos Santos, Larissa Nascimento; de Carvalho, Ricardo José Matos

    2012-01-01

    This article presents a diagnosis of luxury or superior hotels in the city of Natal, located in the state of Rio Grande do Norte, in northeastern Brazil, in what concerns accessibility to the visually impaired. The main objective is to present the guiding principles to design actions and interventions that must be considered in the preparation or revision of technical standards and manuals of good practice in accessibility related to people with visual impairments who are hotel users. The survey showed that the hotels do not meet the normative indications of accessibility, their facilities are in-accessible (have prevented access) or of reduced accessibility and its employees are not prepared to provide adequate hospital services for people with visual impairment. It was concluded that some of the accessibility problems faced by people with visual impairments are also faced by people in general.

  4. OPACs: The User and Subject Access.

    Science.gov (United States)

    Carson, Elizabeth

    1985-01-01

    This survey of the literature reveals user and professional opinions of changes in subject access features available for online public access catalogs. Highlights include expanded access to fields already incorporated into traditional MARC record, access to context of the record, and design of the user interface. Twenty-four references are cited.…

  5. Visual accessibility in graphic design: A client–designer communication failure

    OpenAIRE

    Cornish, Katie; Goodman-Deane, Joy; Ruggeri, Kai; Clarkson, P. John

    2015-01-01

    It is essential that graphic design is visually clear and accessible. However, evidence suggests that a lack of consideration is given to visual accessibility in print-based graphic design. Furthermore, effective client-designer communication is a vital component in this. This paper investigates current graphic design practice, with regard to visual accessibility, specifically focussing on client-designer communication. A survey of 122 graphic designers and clients identified that these two g...

  6. Access to electronic resources by visually impaired people

    Directory of Open Access Journals (Sweden)

    Jenny Craven

    2003-01-01

    Full Text Available Research into access to electronic resources by visually impaired people undertaken by the Centre for Research in Library and Information Management has not only explored the accessibility of websites and levels of awareness in providing websites that adhere to design for all principles, but has sought to enhance understanding of information seeking behaviour of blind and visually impaired people when using digital resources.

  7. Making LibrariesAccessible for Visually Impaired Users: Practical Advice For Librarians

    Directory of Open Access Journals (Sweden)

    Devney Hamilton

    2011-12-01

    Full Text Available This article provides an introduction to making university libraries accessible to visually impaired users. It includes a summary of how visually impaired students access information and how libraries can provide access to materials, devices and software, and staff support to ensure visually impaired students ’ equal opportunity to use the library. The practical advice for librarians are based on interviews with 18 visually impaired university students and professionals who specialize in media, library services and information retrieval.

  8. Differential effects of visual feedback on subjective visual vertical accuracy and precision.

    Directory of Open Access Journals (Sweden)

    Daniel Bjasch

    Full Text Available The brain constructs an internal estimate of the gravitational vertical by integrating multiple sensory signals. In darkness, systematic head-roll dependent errors in verticality estimates, as measured by the subjective visual vertical (SVV, occur. We hypothesized that visual feedback after each trial results in increased accuracy, as physiological adjustment errors (A-/E-effect are likely based on central computational mechanisms and investigated whether such improvements were related to adaptational shifts of perceived vertical or to a higher cognitive strategy. We asked 12 healthy human subjects to adjust a luminous arrow to vertical in various head-roll positions (0 to 120deg right-ear down, 15deg steps. After each adjustment visual feedback was provided (lights on, display of previous adjustment and of an earth-vertical cross. Control trials consisted of SVV adjustments without feedback. At head-roll angles with the largest A-effect (90, 105, and 120deg, errors were reduced significantly (p0.05 influenced. In seven subjects an additional session with two consecutive blocks (first with, then without visual feedback was completed at 90, 105 and 120deg head-roll. In these positions the error-reduction by the previous visual feedback block remained significant over the consecutive 18-24 min (post-feedback block, i.e., was still significantly (p<0.002 different from the control trials. Eleven out of 12 subjects reported having consciously added a bias to their perceived vertical based on visual feedback in order to minimize errors. We conclude that improvements of SVV accuracy by visual feedback, which remained effective after removal of feedback for ≥18 min, rather resulted from a cognitive strategy than by adapting the internal estimate of the gravitational vertical. The mechanisms behind the SVV therefore, remained stable, which is also supported by the fact that SVV precision - depending mostly on otolith input - was not affected by visual

  9. Teach yourself visually Access 2013

    CERN Document Server

    McFedries, Paul

    2013-01-01

    The easy, visual way to learn this popular database program Part of the Office 2013 productivity suite, Access enables you to organize, present, analyze, and share data on a network or over the web. With this Visual guide to show you how, you'll master the fundamentals of this robust database application in no time. Clear, step-by-step instructions are illustrated with full-color screen shots that show exactly what you should see on your screen. Learn to enter new records; create, edit, and design tables and forms; develop queries that generate specific reports; add smart tags to y

  10. Study on the primary visual cortex of visually impaired subjects by means of 123I-IMP SPECT and MRI

    International Nuclear Information System (INIS)

    Ishikawa, Nobuyoshi; Satou, Motohiro; Takeda, Tohoru; Itai, Yuji; Nishijo, Kazushi.

    1995-01-01

    We conducted a study of rCBF in the primary visual cortex of visually impaired subjects who have not been subjected to external stimulation for a long period, by means of 123 I-IMP SPECT and MRI. The four subjects had lost their sight due to brain tumors (n=2), glaucoma (n=1) and trauma (n=1). 123 I-IMP SPECT showed no differences between the visually impaired group and a visually sound control group on visual analysis as well as semiquantitative analysis. MRI of the visually impaired subjects showed no organic changes, such as atrophy, in the occipital cortex. In conclusion, visually impaired subjects have no decrease in rCBF and no anatomical changes in the primary visual cortex. (author)

  11. Accessibility of dynamic web applications with emphasis on visually impaired users

    Directory of Open Access Journals (Sweden)

    Kingsley Okoye

    2014-09-01

    Full Text Available As the internet is fast migrating from static web pages to dynamic web pages, the users with visual impairment find it confusing and challenging when accessing the contents on the web. There is evidence that dynamic web applications pose accessibility challenges for the visually impaired users. This study shows that a difference can be made through the basic understanding of the technical requirement of users with visual impairment and addresses a number of issues pertinent to the accessibility needs for such users. We propose that only by designing a framework that is structurally flexible, by removing unnecessary extras and thereby making every bit useful (fit-for-purpose, will visually impaired users be given an increased capacity to intuitively access e-contents. This theory is implemented in a dynamic website for the visually impaired designed in this study. Designers should be aware of how the screen reading software works to enable them make reasonable adjustments or provide alternative content that still corresponds to the objective content to increase the possibility of offering faultless service to such users. The result of our research reveals that materials can be added to a content repository or re-used from existing ones by identifying the content types and then transforming them into a flexible and accessible one that fits the requirements of the visually impaired through our method (no-frill + agile methodology rather than computing in advance or designing according to a given specification.

  12. Implementing Recommendations From Web Accessibility Guidelines: A Comparative Study of Nondisabled Users and Users With Visual Impairments.

    Science.gov (United States)

    Schmutz, Sven; Sonderegger, Andreas; Sauer, Juergen

    2017-09-01

    The present study examined whether implementing recommendations of Web accessibility guidelines would have different effects on nondisabled users than on users with visual impairments. The predominant approach for making Web sites accessible for users with disabilities is to apply accessibility guidelines. However, it has been hardly examined whether this approach has side effects for nondisabled users. A comparison of the effects on both user groups would contribute to a better understanding of possible advantages and drawbacks of applying accessibility guidelines. Participants from two matched samples, comprising 55 participants with visual impairments and 55 without impairments, took part in a synchronous remote testing of a Web site. Each participant was randomly assigned to one of three Web sites, which differed in the level of accessibility (very low, low, and high) according to recommendations of the well-established Web Content Accessibility Guidelines 2.0 (WCAG 2.0). Performance (i.e., task completion rate and task completion time) and a range of subjective variables (i.e., perceived usability, positive affect, negative affect, perceived aesthetics, perceived workload, and user experience) were measured. Higher conformance to Web accessibility guidelines resulted in increased performance and more positive user ratings (e.g., perceived usability or aesthetics) for both user groups. There was no interaction between user group and accessibility level. Higher conformance to WCAG 2.0 may result in benefits for nondisabled users and users with visual impairments alike. Practitioners may use the present findings as a basis for deciding on whether and how to implement accessibility best.

  13. Accessing Earth Science Data Visualizations through NASA GIBS & Worldview

    Science.gov (United States)

    Cechini, M. F.; Boller, R. A.; Baynes, K.; Wong, M. M.; King, B. A.; Schmaltz, J. E.; De Luca, A. P.; King, J.; Roberts, J. T.; Rodriguez, J.; Thompson, C. K.; Pressley, N. N.

    2017-12-01

    For more than 20 years, the NASA Earth Observing System (EOS) has operated dozens of remote sensing satellites collecting nearly 15 Petabytes of data that span thousands of science parameters. Within these observations are keys the Earth Scientists have used to unlock many things that we understand about our planet. Also contained within these observations are a myriad of opportunities for learning and education. The trick is making them accessible to educators and students in convenient and simple ways so that effort can be spent on lesson enrichment and not overcoming technical hurdles. The NASA Global Imagery Browse Services (GIBS) system and NASA Worldview website provide a unique view into EOS data through daily full resolution visualizations of hundreds of earth science parameters. For many of these parameters, visualizations are available within hours of acquisition from the satellite. For others, visualizations are available for the entire mission of the satellite. Accompanying the visualizations are visual aids such as color legends, place names, and orbit tracks. By using these visualizations, educators and students can observe natural phenomena that enrich a scientific education. This poster will provide an overview of the visualizations available in NASA GIBS and Worldview and how they are accessed. We invite discussion on how the visualizations can be used or improved for educational purposes.

  14. The content of visual working memory alters processing of visual input prior to conscious access: Evidence from pupillometry

    NARCIS (Netherlands)

    Gayet, S.; Paffen, C.L.E.; Guggenmos, M.; Sterzer, P.; Stigchel, S. van der

    2017-01-01

    Visual working memory (VWM) allows for keeping relevant visual information available after termination of its sensory input. Storing information in VWM, however, affects concurrent conscious perception of visual input: initially suppressed visual input gains prioritized access to consciousness when

  15. Robust Subjective Visual Property Prediction from Crowdsourced Pairwise Labels.

    Science.gov (United States)

    Fu, Yanwei; Hospedales, Timothy M; Xiang, Tao; Xiong, Jiechao; Gong, Shaogang; Wang, Yizhou; Yao, Yuan

    2016-03-01

    The problem of estimating subjective visual properties from image and video has attracted increasing interest. A subjective visual property is useful either on its own (e.g. image and video interestingness) or as an intermediate representation for visual recognition (e.g. a relative attribute). Due to its ambiguous nature, annotating the value of a subjective visual property for learning a prediction model is challenging. To make the annotation more reliable, recent studies employ crowdsourcing tools to collect pairwise comparison labels. However, using crowdsourced data also introduces outliers. Existing methods rely on majority voting to prune the annotation outliers/errors. They thus require a large amount of pairwise labels to be collected. More importantly as a local outlier detection method, majority voting is ineffective in identifying outliers that can cause global ranking inconsistencies. In this paper, we propose a more principled way to identify annotation outliers by formulating the subjective visual property prediction task as a unified robust learning to rank problem, tackling both the outlier detection and learning to rank jointly. This differs from existing methods in that (1) the proposed method integrates local pairwise comparison labels together to minimise a cost that corresponds to global inconsistency of ranking order, and (2) the outlier detection and learning to rank problems are solved jointly. This not only leads to better detection of annotation outliers but also enables learning with extremely sparse annotations.

  16. Ubiquitous Accessibility for People with Visual Impairments: Are We There Yet?

    Science.gov (United States)

    Billah, Syed Masum; Ashok, Vikas; Porter, Donald E; Ramakrishnan, I V

    2017-05-01

    Ubiquitous access is an increasingly common vision of computing, wherein users can interact with any computing device or service from anywhere, at any time. In the era of personal computing, users with visual impairments required special-purpose, assistive technologies, such as screen readers, to interact with computers. This paper investigates whether technologies like screen readers have kept pace with, or have created a barrier to, the trend toward ubiquitous access, with a specific focus on desktop computing as this is still the primary way computers are used in education and employment. Towards that, the paper presents a user study with 21 visually-impaired participants, specifically involving the switching of screen readers within and across different computing platforms, and the use of screen readers in remote access scenarios. Among the findings, the study shows that, even for remote desktop access-an early forerunner of true ubiquitous access-screen readers are too limited, if not unusable. The study also identifies several accessibility needs, such as uniformity of navigational experience across devices, and recommends potential solutions. In summary, assistive technologies have not made the jump into the era of ubiquitous access, and multiple, inconsistent screen readers create new practical problems for users with visual impairments.

  17. Accessibility Limits Recall from Visual Working Memory

    Science.gov (United States)

    Rajsic, Jason; Swan, Garrett; Wilson, Daryl E.; Pratt, Jay

    2017-01-01

    In this article, we demonstrate limitations of accessibility of information in visual working memory (VWM). Recently, cued-recall has been used to estimate the fidelity of information in VWM, where the feature of a cued object is reproduced from memory (Bays, Catalao, & Husain, 2009; Wilken & Ma, 2004; Zhang & Luck, 2008). Response…

  18. Teaching the iPhone with Voiceover Accessibility to People with Visual Impairments

    Science.gov (United States)

    Celusnak, Brian M.

    2016-01-01

    Moving from a conventional telephone keypad to a cellular telephone with a touchscreen can seem quite challenging for some people. When one is visually impaired, there is always the option of using VoiceOver, the iPhone's built-in access technology that is designed to allow individuals with visual impairments the ability to access the visual…

  19. Efficient Unsteady Flow Visualization with High-Order Access Dependencies

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiang; Guo, Hanqi; Yuan, Xiaoru

    2016-04-19

    We present a novel high-order access dependencies based model for efficient pathline computation in unsteady flow visualization. By taking longer access sequences into account to model more sophisticated data access patterns in particle tracing, our method greatly improves the accuracy and reliability in data access prediction. In our work, high-order access dependencies are calculated by tracing uniformly-seeded pathlines in both forward and backward directions in a preprocessing stage. The effectiveness of our proposed approach is demonstrated through a parallel particle tracing framework with high-order data prefetching. Results show that our method achieves higher data locality and hence improves the efficiency of pathline computation.

  20. Non-visual Web Browsing: Beyond Web Accessibility.

    Science.gov (United States)

    Ramakrishnan, I V; Ashok, Vikas; Billah, Syed Masum

    2017-07-01

    People with vision impairments typically use screen readers to browse the Web. To facilitate non-visual browsing, web sites must be made accessible to screen readers, i.e., all the visible elements in the web site must be readable by the screen reader. But even if web sites are accessible, screen-reader users may not find them easy to use and/or easy to navigate. For example, they may not be able to locate the desired information without having to listen to a lot of irrelevant contents. These issues go beyond web accessibility and directly impact web usability. Several techniques have been reported in the accessibility literature for making the Web usable for screen reading. This paper is a review of these techniques. Interestingly, the review reveals that understanding the semantics of the web content is the overarching theme that drives these techniques for improving web usability.

  1. Physical and Visual Accessibilities in Intensive Care Units: A Comparative Study of Open-Plan and Racetrack Units.

    Science.gov (United States)

    Rashid, Mahbub; Khan, Nayma; Jones, Belinda

    2016-01-01

    This study compared physical and visual accessibilities and their associations with staff perception and interaction behaviors in 2 intensive care units (ICUs) with open-plan and racetrack layouts. For the study, physical and visual accessibilities were measured using the spatial analysis techniques of Space Syntax. Data on staff perception were collected from 81 clinicians using a questionnaire survey. The locations of 2233 interactions, and the location and length of another 339 interactions in these units were collected using systematic field observation techniques. According to the study, physical and visual accessibilities were different in the 2 ICUs, and clinicians' primary workspaces were physically and visually more accessible in the open-plan ICU. Physical and visual accessibilities affected how well clinicians' knew their peers and where their peers were located in these units. Physical and visual accessibilities also affected clinicians' perception of interaction and communication and of teamwork and collaboration in these units. Additionally, physical and visual accessibilities showed significant positive associations with interaction behaviors in these units, with the open-plan ICU showing stronger associations. However, physical accessibilities were less important than visual accessibilities in relation to interaction behaviors in these ICUs. The implications of these findings for ICU design are discussed.

  2. Subjective visual vertical after treatment of benign paroxysmal positional vertigo

    Directory of Open Access Journals (Sweden)

    Maristela Mian Ferreira

    Full Text Available Abstract Introduction: Otolith function can be studied by testing the subjective visual vertical, because the tilt of the vertical line beyond the normal range is a sign of vestibular dysfunction. Benign paroxysmal positional vertigo is a disorder of one or more labyrinthine semicircular canals caused by fractions of otoliths derived from the utricular macula. Objective: To compare the subjective visual vertical with the bucket test before and immediately after the particle repositioning maneuver in patients with benign paroxysmal positional vertigo. Methods: We evaluated 20 patients. The estimated position where a fluorescent line within a bucket reached the vertical position was measured before and immediately after the particle repositioning maneuver. Data were tabulated and statistically analyzed. Results: Before repositioning maneuver, 9 patients (45.0% had absolute values of the subjective visual vertical above the reference standard and 2 (10.0% after the maneuver; the mean of the absolute values of the vertical deviation was significantly lower after the intervention (p < 0.001. Conclusion: There is a reduction of the deviations of the subjective visual vertical, evaluated by the bucket test, immediately after the particle repositioning maneuver in patients with benign paroxysmal positional vertigo.

  3. Diffusion accessibility as a method for visualizing macromolecular surface geometry.

    Science.gov (United States)

    Tsai, Yingssu; Holton, Thomas; Yeates, Todd O

    2015-10-01

    Important three-dimensional spatial features such as depth and surface concavity can be difficult to convey clearly in the context of two-dimensional images. In the area of macromolecular visualization, the computer graphics technique of ray-tracing can be helpful, but further techniques for emphasizing surface concavity can give clearer perceptions of depth. The notion of diffusion accessibility is well-suited for emphasizing such features of macromolecular surfaces, but a method for calculating diffusion accessibility has not been made widely available. Here we make available a web-based platform that performs the necessary calculation by solving the Laplace equation for steady state diffusion, and produces scripts for visualization that emphasize surface depth by coloring according to diffusion accessibility. The URL is http://services.mbi.ucla.edu/DiffAcc/. © 2015 The Protein Society.

  4. Use of subjective and objective criteria to categorise visual disability.

    Science.gov (United States)

    Kajla, Garima; Rohatgi, Jolly; Dhaliwal, Upreet

    2014-04-01

    Visual disability is categorised using objective criteria. Subjective measures are not considered. To use subjective criteria along with objective ones to categorise visual disability. Ophthalmology out-patient department; teaching hospital; observational study. Consecutive persons aged >25 years, with vision disability; group-zero: normal range of vision, to group-X: no perception of light, bilaterally. Snellen's vision; binocular contrast sensitivity (Pelli-Robson chart); automated binocular visual field (Humphrey; Esterman test); and vision-related quality of life (Indian Visual Function Questionnaire-33; IND-VFQ33) were recorded. SPSS version-17; Kruskal-wallis test was used to compare contrast sensitivity and visual fields across groups, and Mann-Whitney U test for pair-wise comparison (Bonferroni adjustment; P visual fields were comparable for differing disability grades except when disability was severe (P disability grades but comparable for groups III (78.51 ± 6.86) and IV (82.64 ± 5.80), and groups IV and V (77.23 ± 3.22); these were merged to generate group 345; similarly, global scores were comparable for adjacent groups V and VI (72.53 ± 6.77), VI and VII (74.46 ± 4.32), and VII and VIII (69.12 ± 5.97); these were merged to generate group 5678; thereafter, contrast sensitivity and global and individual IND-VFQ33 scores could differentiate between different grades of disability in the five new groups. Subjective criteria made it possible to objectively reclassify visual disability. Visual disability grades could be redefined to accommodate all from zero-100%.

  5. Subject Access Project. Third Quarterly Report.

    Science.gov (United States)

    Atherton, Pauline

    This third quarterly report for the period January to March 1977 describes the production schedule, records, and estimated costs and times in creating the Subject Access Project data base. Plans for on-line use of the data base and search strategy design are outlined. A table of specifications for preparing the data base for on-line searching is…

  6. Accessibility of health clubs for people with mobility disabilities and visual impairments.

    Science.gov (United States)

    Rimmer, James H; Riley, Barth; Wang, Edward; Rauworth, Amy

    2005-11-01

    We sought to examine the accessibility of health clubs to persons with mobility disabilities and visual impairments. We assessed 35 health clubs and fitness facilities as part of a national field trial of a new instrument, Accessibility Instruments Measuring Fitness and Recreation Environments (AIMFREE), designed to assess accessibility of fitness facilities in the following domains: (1) built environment, (2) equipment, (3) swimming pools, (4) information, (5) facility policies, and (6) professional behavior. All facilities had a low to moderate level of accessibility. Some of the deficiencies concerned specific Americans with Disabilities Act guidelines pertaining to the built environment, whereas other deficiency areas were related to aspects of the facilities' equipment, information, policies, and professional staff. Persons with mobility disabilities and visual impairments have difficulty accessing various areas of fitness facilities and health clubs. AIMFREE is an important tool for increasing awareness of these accessibility barriers for people with disabilities.

  7. Regulations To Be Made In Urban Areas In Order To Improve Accessibility Of The “Visually-Impaired

    Directory of Open Access Journals (Sweden)

    Pelin Gökgür

    2014-06-01

    Full Text Available In our country, disabled people encounter many problems in integrating with the city and city life. The most important one is the "accessibility" in the physical space. Providing accessibility require disabled to move without being in need of any help, without any prevention and to participate in the life activities. It is seen in our country that the obstacle-free walkways for the disabled do not exist in the cities including the pedestrian areas, the legal arrangements with respect thereto are not yet able to achieve the required conditions in the physical environment, and the required sanctions and controls are not sufficient. Moreover, inability to present accurately the difference in the needs as based on the disability type is exposed in the problems that occur in the arrangements realized. The basic needs of "visually-impaired" people in the urban space, which constitutes the subject matter of the study can be listed as; safety, to understand where s/he is going, to know where s/he is and to obtain information about the surrounding. For the visually-impaired people to obtain such needs depends on their ability to move alone in the urban space. One of the most important issues in achieving this is "orientation". "Orientation" involves the process of determination of the person's own position and relation with the important objects around. It is known that the "accessibility" of a visually-impaired person is based on orientation and the arrangements in the physical environment in achieving this are very important. In this study, the purpose is to present the significance of "orientation" directed to increase the accessibility of the "visually-impaired" people in the urban space and as based on this, to discuss "the arrangements required to be realized in the physical environment”.

  8. Accessibility of Shared Space by Visually Challenged People

    NARCIS (Netherlands)

    Melis-Dankers, Bart J.M.; Havik, Else M.; Steyvers, Frank J.J.M.; Petrie, Helen; Kooijman, Aart C.; Kouroupetroglou, Georgios

    Shared Space is a concept that comprises the design of a public space. There are concerns about the accessibility of Shared Spaces for people who are visually challenged. In this paper we give a systematic overview of the appearance of Shared Spaces in the Netherlands and the consequences that these

  9. Visual inspection requirements for high-reliability random-access memories

    International Nuclear Information System (INIS)

    Andrade, A.; McHenery, J.

    1981-09-01

    Visual inspection requirements are given for random-access memories for deep-space satellite electronics. The requirements, based primarily on Military Standard 883B, are illustrated in the order of their manufacturing operation to clarify and facilitate inspection procedures

  10. Filling the Astronomical Void - A Visual Medium for a Visual Subject

    Science.gov (United States)

    Ryan, J.

    1996-12-01

    Astronomy is fundamentally a visual subject. The modern science of astronomy has at its foundation the ancient art of observing the sky visually. The visual elements of astronomy are arguably the most important. Every person in the entire world is affected by visually-observed astronomical phenomena such as the seasonal variations in daylight. However, misconceptions abound and the average person cannot recognize the simple signs in the sky that point to the direction, the hour and the season. Educators and astronomy popularizers widely lament that astronomy is not appreciated in our society. Yet, there is a remarkable dearth of popular literature for teaching the visual elements of astronomy. This is what I refer to as *the astronomical void.* Typical works use illustrations sparsely, relying most heavily on text-based descriptions of the visual astronomical phenomena. Such works leave significant inferential gaps to the inexperienced reader, who is unequipped for making astronomical observations. Thus, the astronomical void remains unfilled by much of the currently available literature. I therefore propose the introduction of a visually-oriented medium for teaching the visual elements of Astronomy. To this end, I have prepared a series of astronomy "comic strips" that are intended to fill the astronomical void. By giving the illustrations the central place, the comic strip medium permits the depiction of motion and other sequential activity, thus effectively representing astronomical phenomena. In addition to the practical advantages, the comic strip is a "user friendly" medium that is inviting and entertaining to a reader. At the present time, I am distributing a monthly comic strip entitled *Starman*, which appears in the newsletters of over 120 local astronomy organizations and on the web at http://www.cyberdrive.net/ starman. I hope to eventually publish a series of full-length books and believe that astronomical comic strips will help expand the perimeter of

  11. [The subject repositories of strategy of the Open Access initiative].

    Science.gov (United States)

    Soares Guimarães, M C; da Silva, C H; Horsth Noronha, I

    2012-11-01

    The subject repositories are defined as a set of digital objects resulting from the research related to a specific disciplinary field and occupy a still restricted space in the discussion agenda of the Free Access Movement when compared to amplitude reached in the discussion of Institutional Repositories. Although the Subject Repository comes to prominence in the field, especially for the success of initiatives such as the arXiv, PubMed and E-prints, the literature on the subject is recognized as very limited. Despite its roots in the Library and Information Science, and focus on the management of disciplinary collections (subject area literature), there is little information available about the development and management of subject repositories. The following text seeks to make a brief summary on the topic as a way to present the potential to develop subject repositories in order to strengthen the initiative of open access.

  12. Difference in Subjective Accessibility of On Demand Recall of Visual, Taste, and Olfactory Memories

    Directory of Open Access Journals (Sweden)

    Petr Zach

    2018-01-01

    Full Text Available We present here significant difference in the evocation capability between sensory memories (visual, taste, and olfactory throughout certain categories of the population. As object for this memory recall we selected French fries that are simple and generally known. From daily life we may intuitively feel that there is much better recall of the visual and auditory memory compared to the taste and olfactory ones. Our results in young (age 12–21 years mostly females and some males show low capacity for smell and taste memory recall compared to far greater visual memory recall. This situation raises question whether we could train smell and taste memory recall so that it could become similar to visual or auditory ones. In our article we design technique of the volunteers training that could potentially lead to an increase in the capacity of their taste and olfactory memory recollection.

  13. Layers Of Visual Imagination And Degrees Of Subjectivity In Listening Experiences Exploring Visual Imagination In Acousmatic Composition And Listening

    Directory of Open Access Journals (Sweden)

    Stefano Poillucci

    2015-08-01

    Full Text Available Abstract Electroacoustic music especially Acousmatic is often perceived differently between listeners and a wide variety of visual images is evoked. This because of the spectromorphological qualities and the abstract reality in which this kind of music carries the listener into. In everyday life it seems that we have a natural tendency to assess and understand reality around us and to quantise how and if the perceived circumstances could affect our wellbeing. Some studies also affirm that brain and the biological function of the sensory and perceptual processes are commonly identical in each listener. This gives evidence that arises the interest to investigate which variations the subjectivity of visual imagery depends on and if it is possible to unfold it in various layers. This experimental research has taken in consideration questionnaire-based listening tests to gather details from each listening experience and to get a better understanding of the visual imagery evoked by electroacoustic compositions into the listeners mind and its degrees of objectivity and subjectivity. The compositions used in the experiment were both composed by the author with the intention of guiding listeners into their personal perceptual-imaginative journey by delivering encoded perhaps objective sonic cues. This paper is a theoretical inter-disciplinary analysis backed by research on the foundations of senses perception cognition emotions etc. An artistic approach based on scientific evidences led to the theorization of layers of imagination and their bias to produce visual images with a degree of subjectivity that lies into micro aspects of sounds and in the perceptual and innate knowledge of each individual. Glossary The terms listed here have been invented or readapted for the purpose of the study in order to make concepts easier to assimilate and understand. Aural World sonic world with intrinsic features Smalley 1997. The purely auditory realm which an

  14. The automatic visual simulation of words: A memory reactivated mask slows down conceptual access.

    Science.gov (United States)

    Rey, Amandine E; Riou, Benoit; Vallet, Guillaume T; Versace, Rémy

    2017-03-01

    How do we represent the meaning of words? The present study assesses whether access to conceptual knowledge requires the reenactment of the sensory components of a concept. The reenactment-that is, simulation-was tested in a word categorisation task using an innovative masking paradigm. We hypothesised that a meaningless reactivated visual mask should interfere with the simulation of the visual dimension of concrete words. This assumption was tested in a paradigm in which participants were not aware of the link between the visual mask and the words to be processed. In the first phase, participants created a tone-visual mask or tone-control stimulus association. In the test phase, they categorised words that were presented with 1 of the tones. Results showed that words were processed more slowly when they were presented with the reactivated mask. This interference effect was only correlated with and explained by the value of the visual perceptual strength of the words (i.e., our experience with the visual dimensions associated with concepts) and not with other characteristics. We interpret these findings in terms of word access, which may involve the simulation of sensory features associated with the concept, even if participants were not explicitly required to access visual properties. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  15. Visual BOLD Response in Late Blind Subjects with Argus II Retinal Prosthesis.

    Directory of Open Access Journals (Sweden)

    E Castaldi

    2016-10-01

    Full Text Available Retinal prosthesis technologies require that the visual system downstream of the retinal circuitry be capable of transmitting and elaborating visual signals. We studied the capability of plastic remodeling in late blind subjects implanted with the Argus II Retinal Prosthesis with psychophysics and functional MRI (fMRI. After surgery, six out of seven retinitis pigmentosa (RP blind subjects were able to detect high-contrast stimuli using the prosthetic implant. However, direction discrimination to contrast modulated stimuli remained at chance level in all of them. No subject showed any improvement of contrast sensitivity in either eye when not using the Argus II. Before the implant, the Blood Oxygenation Level Dependent (BOLD activity in V1 and the lateral geniculate nucleus (LGN was very weak or absent. Surprisingly, after prolonged use of Argus II, BOLD responses to visual input were enhanced. This is, to our knowledge, the first study tracking the neural changes of visual areas in patients after retinal implant, revealing a capacity to respond to restored visual input even after years of deprivation.

  16. Effects of lead on the visual system of occupationally exposed subjects

    Energy Technology Data Exchange (ETDEWEB)

    Cavalleri, A.; Trimarchi, F.; Gelmi, C.; Baruffini, A.; Minoia, C.; Biscaldi, G.; Gallo, G.

    1982-01-01

    A quantitative measurement of visual field in mesopic adaptation was performed for 35 workers occupationally exposed to lead and 35 referents matched for age, smoking, and alcohol consumption. The mean level (+/- SD) of lead in blood was 47 +/- 16 microgram/100 ml (2.25 +/- 0.77 mumol/l) (range 21-82 microgram/100 ml (1.01-3.94 mumol/l)). In 10 exposed subjects a central scotoma was found that was not evidenced in any of the referents. A highly significant decrease in visual sensitivity was observed for the exposed subjects a central scotoma was found that was not evidenced in any of the referents. A highly significant decrease in visual sensitivity was observed for the exposed subjects. The results point to damage of central and peripheral optic nerve fibers. In the most severe cases, central vision is preferentially affected, and therefore the results are suggestive of subclinical optic neuropathy.

  17. Accessible engineering drawings for visually impaired machine operators.

    Science.gov (United States)

    Ramteke, Deepak; Kansal, Gayatri; Madhab, Benu

    2014-01-01

    An engineering drawing provides manufacturing information to a machine operator. An operator plans and executes machining operations based on this information. A visually impaired (VI) operator does not have direct access to the drawings. Drawing information is provided to them verbally or by using sample parts. Both methods have limitations that affect the quality of output. Use of engineering drawings is a standard practice for every industry; this hampers employment of a VI operator. Accessible engineering drawings are required to increase both independence, as well as, employability of VI operators. Today, Computer Aided Design (CAD) software is used for making engineering drawings, which are saved in CAD files. Required information is extracted from the CAD files and converted into Braille or voice. The authors of this article propose a method to make engineering drawings information directly accessible to a VI operator.

  18. Accessibility of shared space for visually impaired persons : A comparative field study

    NARCIS (Netherlands)

    Havik, Else; Steyvers, Franciscus J.J.M.; Kooijman, Aart; Melis, Bart

    Shared Space is a concept that comprises the design and planning process of a public space. There are concerns about the accessibility of Shared Spaces for people who are visually impaired. In a comparative field study, the wayfinding performance of 25 visually impaired persons (VIPs) was observed

  19. Visual perception of spatial subjects

    International Nuclear Information System (INIS)

    Osterloh, K.R.S.; Ewert, U.

    2007-01-01

    Principally, any imaging technology consists of two consecutive, though strictly separated processes: data acquisition and subsequent processing to generate an image that can be looked at, either on a monitor screen or printed on paper. Likewise, the physiological process of viewing can be separated into vision and perception, though these processes are much more overlapping. Understanding the appearance of a subject requires the entire sequence from receiving the information carried e.g. by photons up to an appropriate processing leading to the perception of the subject shown. As a consequence, the imagination of a subject is a result of both, technological and physiological processes. Whenever an evaluation of an image is critical, also the physiological part of the processing should be considered. However, an image has two dimensions in the first place and reality is spatial, it has three dimensions. This problem has been tackled on a philosophical level at least since Platon's famous discussion on the shadow image in a dark cave. The mere practical point is which structural details can be perceived and what may remain undetected depending on the mode of presentation. This problem cannot be resolved without considering each single step of visual perception. Physiologically, there are three 'tools' available to understanding the spatial structure of a subject: binocular viewing, following the course of perspective projection and motion to collect multiple aspects. Artificially, an object may be cut in various ways to display the interior or covering parts could be made transparent within a model. Samples will be shown how certain details of a subject can be emphasised or hidden depending on the way of presentation. It needs to be discussed what might help to perceive the true spatial structure of a subject with all relevant details and what could be misleading. (authors)

  20. Visual perception of spatial subjects

    Energy Technology Data Exchange (ETDEWEB)

    Osterloh, K.R.S.; Ewert, U. [Federal Institute for Materials Research and Testing (BAM), Berlin (Germany)

    2007-07-01

    Principally, any imaging technology consists of two consecutive, though strictly separated processes: data acquisition and subsequent processing to generate an image that can be looked at, either on a monitor screen or printed on paper. Likewise, the physiological process of viewing can be separated into vision and perception, though these processes are much more overlapping. Understanding the appearance of a subject requires the entire sequence from receiving the information carried e.g. by photons up to an appropriate processing leading to the perception of the subject shown. As a consequence, the imagination of a subject is a result of both, technological and physiological processes. Whenever an evaluation of an image is critical, also the physiological part of the processing should be considered. However, an image has two dimensions in the first place and reality is spatial, it has three dimensions. This problem has been tackled on a philosophical level at least since Platon's famous discussion on the shadow image in a dark cave. The mere practical point is which structural details can be perceived and what may remain undetected depending on the mode of presentation. This problem cannot be resolved without considering each single step of visual perception. Physiologically, there are three 'tools' available to understanding the spatial structure of a subject: binocular viewing, following the course of perspective projection and motion to collect multiple aspects. Artificially, an object may be cut in various ways to display the interior or covering parts could be made transparent within a model. Samples will be shown how certain details of a subject can be emphasised or hidden depending on the way of presentation. It needs to be discussed what might help to perceive the true spatial structure of a subject with all relevant details and what could be misleading. (authors)

  1. Subjective visual vertical assessment with mobile virtual reality system

    Directory of Open Access Journals (Sweden)

    Ingrida Ulozienė

    Full Text Available Background and objective: The subjective visual vertical (SVV is a measure of a subject's perceived verticality, and a sensitive test of vestibular dysfunction. Despite this, and consequent upon technical and logistical limitations, SVV has not entered mainstream clinical practice. The aim of the study was to develop a mobile virtual reality based system for SVV test, evaluate the suitability of different controllers and assess the system's usability in practical settings. Materials and methods: In this study, we describe a novel virtual reality based system that has been developed to test SVV using integrated software and hardware, and report normative values across healthy population. Participants wore a mobile virtual reality headset in order to observe a 3D stimulus presented across separate conditions – static, dynamic and an immersive real-world (“boat in the sea” SVV tests. The virtual reality environment was controlled by the tester using a Bluetooth connected controllers. Participants controlled the movement of a vertical arrow using either a gesture control armband or a general-purpose gamepad, to indicate perceived verticality. We wanted to compare 2 different methods for object control in the system, determine normal values and compare them with literature data, to evaluate the developed system with the help of the system usability scale questionnaire and evaluate possible virtually induced dizziness with the help of subjective visual analog scale. Results: There were no statistically significant differences in SVV values during static, dynamic and virtual reality stimulus conditions, obtained using the two different controllers and the results are compared to those previously reported in the literature using alternative methodologies. The SUS scores for the system were high, with a median of 82.5 for the Myo controller and of 95.0 for the Gamepad controller, representing a statistically significant difference between the two

  2. A Flexible Visualization Tool for Rapid Access to EFIT Results

    International Nuclear Information System (INIS)

    Zhang Ruirui; Xiao Bingjia; Luo Zhengping

    2014-01-01

    This paper introduces the design and implementation of an interactive tool, the EASTViewer, for the visualization of plasma equilibrium reconstruction results for EAST (the Experimental Advanced Superconducting Tokamak). Aimed at the operating system independently, Python, when combined with the PyGTK toolkit, is used as the programming language. Using modular design, the EASTViewer provides a unified interface with great flexibility. It is easy to access numerous data sources either from local data files or an MDSplus tree, and with the pre-defined configuration files, it can be extended to other tokamaks. The EASTViewer has been used as the major tool to visualize equilibrium data since the second EAST campaign in 2008, and it has been verified that the EASTViewer features a user-friendly interface, and has easy access to numerous data sources and cross-platforms. (fusion engineering)

  3. The dynamics of visual experience, an EEG study of subjective pattern formation.

    Directory of Open Access Journals (Sweden)

    Mark A Elliott

    Full Text Available BACKGROUND: Since the origin of psychological science a number of studies have reported visual pattern formation in the absence of either physiological stimulation or direct visual-spatial references. Subjective patterns range from simple phosphenes to complex patterns but are highly specific and reported reliably across studies. METHODOLOGY/PRINCIPAL FINDINGS: Using independent-component analysis (ICA we report a reduction in amplitude variance consistent with subjective-pattern formation in ventral posterior areas of the electroencephalogram (EEG. The EEG exhibits significantly increased power at delta/theta and gamma-frequencies (point and circle patterns or a series of high-frequency harmonics of a delta oscillation (spiral patterns. CONCLUSIONS/SIGNIFICANCE: Subjective-pattern formation may be described in a way entirely consistent with identical pattern formation in fluids or granular flows. In this manner, we propose subjective-pattern structure to be represented within a spatio-temporal lattice of harmonic oscillations which bind topographically organized visual-neuronal assemblies by virtue of low frequency modulation.

  4. Visually representing reality: aesthetics and accessibility aspects

    Science.gov (United States)

    van Nes, Floris L.

    2009-02-01

    This paper gives an overview of the visual representation of reality with three imaging technologies: painting, photography and electronic imaging. The contribution of the important image aspects, called dimensions hereafter, such as color, fine detail and total image size, to the degree of reality and aesthetic value of the rendered image are described for each of these technologies. Whereas quite a few of these dimensions - or approximations, or even only suggestions thereof - were already present in prehistoric paintings, apparent motion and true stereoscopic vision only recently were added - unfortunately also introducing accessibility and image safety issues. Efforts are made to reduce the incidence of undesirable biomedical effects such as photosensitive seizures (PSS), visually induced motion sickness (VIMS), and visual fatigue from stereoscopic images (VFSI) by international standardization of the image parameters to be avoided by image providers and display manufacturers. The history of this type of standardization, from an International Workshop Agreement to a strategy for accomplishing effective international standardization by ISO, is treated at some length. One of the difficulties to be mastered in this process is the reconciliation of the, sometimes opposing, interests of vulnerable persons, thrill-seeking viewers, creative video designers and the game industry.

  5. Difference in Subjective Accessibility of On Demand Recall of Visual, Taste, and Olfactory Memories

    OpenAIRE

    Zach, Petr; Zimmelová, Petra; Mrzílková, Jana; Kutová, Martina

    2018-01-01

    We present here significant difference in the evocation capability between sensory memories (visual, taste, and olfactory) throughout certain categories of the population. As object for this memory recall we selected French fries that are simple and generally known. From daily life we may intuitively feel that there is much better recall of the visual and auditory memory compared to the taste and olfactory ones. Our results in young (age 12–21 years) mostly females and some males show low cap...

  6. Relationship between macular pigment and visual function in subjects with early age-related macular degeneration.

    Science.gov (United States)

    Akuffo, Kwadwo Owusu; Nolan, John M; Peto, Tunde; Stack, Jim; Leung, Irene; Corcoran, Laura; Beatty, Stephen

    2017-02-01

    To investigate the relationship between macular pigment (MP) and visual function in subjects with early age-related macular degeneration (AMD). 121 subjects with early AMD enrolled as part of the Central Retinal Enrichment Supplementation Trial (CREST; ISRCTN13894787) were assessed using a range of psychophysical measures of visual function, including best corrected visual acuity (BCVA), letter contrast sensitivity (CS), mesopic and photopic CS, mesopic and photopic glare disability (GD), photostress recovery time (PRT), reading performance and subjective visual function, using the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). MP was measured using customised heterochromatic flicker photometry. Letter CS, mesopic and photopic CS, photopic GD and mean reading speed were each significantly (p0.05, for all). MP relates positively to many measures of visual function in unsupplemented subjects with early AMD. The CREST trial will investigate whether enrichment of MP influences visual function among those afflicted with this condition. ISRCTN13894787. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  7. Avaliação da vertical visual subjetiva em indivíduos brasileiros normais Subjective visual vertical evaluation in normal Brazilian subjects

    Directory of Open Access Journals (Sweden)

    Aline M. Kozoroski Kanashiro

    2007-06-01

    Full Text Available A função otolítica pode ser avaliada pela Vertical Visual Subjetiva (VVS que determina a capacidade de um indivíduo julgar se objetos estão na posição vertical na ausência de outras referências visuais. O objetivo deste estudo foi avaliar a VVS em indivíduos brasileiros normais usando um aparelho portátil. As medidas da VVS foram realizadas em 160 indivíduos (16 a 85 anos. O valor médio da VVS foi obtido após dez ajustes. A VVS teve valores médios entre -2,0º e +2,4º (média=0,18º, e DP=0,77º. Não houve diferença entre as médias da VVS em relação à idade (teste de Kruskal-Wallis; p=0,40, mas as faixas etárias maiores tiveram variância maior (teste de Levene; p=0,016. Os valores da VVS encontrados neste estudo foram semelhantes aos registrados na literatura. Não houve diferença nas médias das inclinações da VVS de acordo com a idade, mas foi encontrada maior variância entre indivíduos mais idosos.Otolith function can be evaluated by subjective visual vertical (SVV that determine the capacity of a subject to judge if the objects are on vertical position with absence of any visual reference. The aim of this study was to evaluate the SVV in a sample of normal Brazilian subjects using a portable device. Measurements of SVV were performed in 160 normal subjects (aged from 16 to 85. SVV mean value was obtained after ten adjustments. SVV mean values ranged from -2.0º to +2.4º (mean=0.18º, and SD=0.77. Considering all age groups, there was no difference of SVV mean values (Kruskal-Wallis test; p=0.40, but older groups had a greater variance (Levene test; p=0.016. SVV values observed in this study are comparable to those described in previous studies. Although there was no difference in mean SVV-inclination according to age, there was a greater variance in older subjects.

  8. Cognitive factors in subjective stabilization of the visual world.

    Science.gov (United States)

    Bridgeman, B

    1981-08-01

    If an eye movement signal is fed through a galvanic mirror, to move a projected image which a subject is inspecting, prominent objects in the image may seem to jiggle or jump with the the eye when the gain is just below the threshold for detecting a jump of the entire image (Brune and Lücking 1969). We have refined and extended this observation with both naive and practiced subjects, finding results which contradict all of the current theories about the mechanism of stabilization of the visual world and suggest that cognitive factors in perception important influences on the stabilization process. Using this method with a paired photocell system to detect horizontal eye movements, some subjects saw a prominent object in the display jump slightly while the rest of the scene remained stable. The task was done first with landscape slides, then repeated with Escher prints where two sets of alternating figures completely filled the image. Subjects could concentrate on one set of forms as the "figure" and the other as the "ground", and reverse the two at will. In a majority of practiced subjects and in smaller proportion of naive subjects, motion of part of the "figure" was seen regardless of which alternative set of forms constituted it. Reversibility of the effect controlled for influence of object size, brightness, etc. in inducing the selective jump. These and related observations show that cognitive or attentional variables are as important as image properties or gain alone in determining subjective stabilization of the visual world, though current theories (inflow, outflow, cancellation, etc.) consider image position to be simple variable. Another experiment showed that image movement on the retina during saccades cannot explain saccadic suppression of displacement.

  9. ARCAS (ACACIA Regional Climate-data Access System) -- a Web Access System for Climate Model Data Access, Visualization and Comparison

    Science.gov (United States)

    Hakkarinen, C.; Brown, D.; Callahan, J.; hankin, S.; de Koningh, M.; Middleton-Link, D.; Wigley, T.

    2001-05-01

    A Web-based access system to climate model output data sets for intercomparison and analysis has been produced, using the NOAA-PMEL developed Live Access Server software as host server and Ferret as the data serving and visualization engine. Called ARCAS ("ACACIA Regional Climate-data Access System"), and publicly accessible at http://dataserver.ucar.edu/arcas, the site currently serves climate model outputs from runs of the NCAR Climate System Model for the 21st century, for Business as Usual and Stabilization of Greenhouse Gas Emission scenarios. Users can select, download, and graphically display single variables or comparisons of two variables from either or both of the CSM model runs, averaged for monthly, seasonal, or annual time resolutions. The time length of the averaging period, and the geographical domain for download and display, are fully selectable by the user. A variety of arithmetic operations on the data variables can be computed "on-the-fly", as defined by the user. Expansions of the user-selectable options for defining analysis options, and for accessing other DOD-compatible ("Distributed Ocean Data System-compatible") data sets, residing at locations other than the NCAR hardware server on which ARCAS operates, are planned for this year. These expansions are designed to allow users quick and easy-to-operate web-based access to the largest possible selection of climate model output data sets available throughout the world.

  10. KML-Based Access and Visualization of High Resolution LiDAR Topography

    Science.gov (United States)

    Crosby, C. J.; Blair, J. L.; Nandigam, V.; Memon, A.; Baru, C.; Arrowsmith, J. R.

    2008-12-01

    Over the past decade, there has been dramatic growth in the acquisition of LiDAR (Light Detection And Ranging) high-resolution topographic data for earth science studies. Capable of providing digital elevation models (DEMs) more than an order of magnitude higher resolution than those currently available, LiDAR data allow earth scientists to study the processes that contribute to landscape evolution at resolutions not previously possible yet essential for their appropriate representation. These datasets also have significant implications for earth science education and outreach because they provide an accurate representation of landforms and geologic hazards. Unfortunately, the massive volume of data produced by LiDAR mapping technology can be a barrier to their use. To make these data available to a larger user community, we have been exploring the use of Keyhole Markup Language (KML) and Google Earth to provide access to LiDAR data products and visualizations. LiDAR digital elevation models are typically delivered in a tiled format that lends itself well to a KML-based distribution system. For LiDAR datasets hosted in the GEON OpenTopography Portal (www.opentopography.org) we have developed KML files that show the extent of available LiDAR DEMs and provide direct access to the data products. Users interact with these KML files to explore the extent of the available data and are able to select DEMs that correspond to their area of interest. Selection of a tile loads a download that the user can then save locally for analysis in their software of choice. The GEON topography system also has tools available that allow users to generate custom DEMs from LiDAR point cloud data. This system is powerful because it enables users to access massive volumes of raw LiDAR data and to produce DEM products that are optimized to their science applications. We have developed a web service that converts the custom DEM models produced by the system to a hillshade that is delivered to

  11. Maintenance information management using access/visual basic

    International Nuclear Information System (INIS)

    Memory A, Michael; Cumbia W, Brad

    1998-01-01

    The Accelerator Electronic Support Group (AES) is the group responsible for maintaining over 100 subsystems of the Nuclear Physics Accelerator at Jefferson Lab. Presently, there are 30 employees in the AES group. It is each individual's responsibility to make entries into the AES Database. This Access/Visual Basic based database is the center for all work performed to the Accelerator by the AES group. At any time, an AES technologist can supply valuable information needed to track pending maintenance, data analysis of recurring problems, inventory tracking and the ability to export all of this information to a web based electronic log generated by Jefferson Lab Operations Group

  12. Characterizing head motion in three planes during combined visual and base of support disturbances in healthy and visually sensitive subjects.

    Science.gov (United States)

    Keshner, E A; Dhaher, Y

    2008-07-01

    Multiplanar environmental motion could generate head instability, particularly if the visual surround moves in planes orthogonal to a physical disturbance. We combined sagittal plane surface translations with visual field disturbances in 12 healthy (29-31 years) and 3 visually sensitive (27-57 years) adults. Center of pressure (COP), peak head angles, and RMS values of head motion were calculated and a three-dimensional model of joint motion was developed to examine gross head motion in three planes. We found that subjects standing quietly in front of a visual scene translating in the sagittal plane produced significantly greater (pplane of platform motion significantly increased (phistory of vestibular disorder produced large, delayed compensatory head motion. Orthogonal head motions were significantly greater in visually sensitive than in healthy subjects in the dark (pplanes orthogonal to the direction of a physical perturbation. These results suggest that the mechanisms controlling head orientation in space are distinct from those that control trunk orientation in space. These behaviors would have been missed if only COP data were considered. Data suggest that rehabilitation training can be enhanced by combining visual and mechanical perturbation paradigms.

  13. Characterizing the nature of visual conscious access: the distinction between features and locations.

    Science.gov (United States)

    Huang, Liqiang

    2010-08-24

    The difference between the roles of features and locations has been a central topic in the theoretical debates on visual attention. A recent theory proposed that momentary visual awareness is limited to one Boolean map, that is the linkage of one feature per dimension with a set of locations (L. Huang & H. Pashler, 2007). This theory predicts that: (a) access to the features of a set of objects is inefficient whereas access to their locations is efficient; (b) shuffling the locations of objects disrupts access to their features whereas shuffling the features of objects has little impact on access to their locations. Both of these predictions were confirmed in Experiments 1 and 2. Experiments 3 and 4 showed that this feature/location distinction remains when the task involves the detection of changes to old objects rather than the coding of new objects. Experiments 5 and 6 showed that, in a pre-specified set, one missing location can be readily detected, but detecting one missing color is difficult. Taken together, multiple locations seem to be accessed and represented together as a holistic pattern, but features have to be handled as separate labels, one at a time, and do not constitute a pattern in featural space.

  14. The Impact of Cataract Surgery on Subjective Visual Functions and ...

    African Journals Online (AJOL)

    2016-12-13

    Dec 13, 2016 ... The second eye surgery confers additional gains in terms of VF and QoL in ... subjective visual function (VF) and QoL of our patients.[10-12]. Most similar ... For reprints contact: reprints@medknow.com. How to cite this article: ...

  15. Mining Social Tagging Data for Enhanced Subject Access for Readers and Researchers

    Science.gov (United States)

    Lawson, Karen G.

    2009-01-01

    Social tagging enables librarians to partner with users to provide enhanced subject access. This paper quantifies and compares LC subject headings from each of 31 different subject divisions with user tags from Amazon.com and LibraryThing assigned to the same titles. The intersection and integration of these schemas is described and evaluated.…

  16. Vector model for mapping of visual space to subjective 4-D sphere

    International Nuclear Information System (INIS)

    Matuzevicius, Dalius; Vaitkevicius, Henrikas

    2014-01-01

    Here we present a mathematical model of binocular vision that maps a visible physical world to a subjective perception of it. The subjective space is a set of 4-D vectors whose components are outputs of four monocular neurons from each of the two eyes. Monocular neurons have one of the four types of concentric receptive fields with Gabor-like weighting coefficients. Next this vector representation of binocular vision is implemented as a pool of neurons where each of them is selective to the object's particular location in a 3-D visual space. Formally each point of the visual space is being projected onto a 4-D sphere. Proposed model allows determination of subjective distances in depth and direction, provides computational means for determination of Panum's area and explains diplopia and allelotropia

  17. AR4VI: AR as an Accessibility Tool for People with Visual Impairments.

    Science.gov (United States)

    Coughlan, James M; Miele, Joshua

    2017-10-01

    Although AR technology has been largely dominated by visual media, a number of AR tools using both visual and auditory feedback have been developed specifically to assist people with low vision or blindness - an application domain that we term Augmented Reality for Visual Impairment (AR4VI). We describe two AR4VI tools developed at Smith-Kettlewell, as well as a number of pre-existing examples. We emphasize that AR4VI is a powerful tool with the potential to remove or significantly reduce a range of accessibility barriers. Rather than being restricted to use by people with visual impairments, AR4VI is a compelling universal design approach offering benefits for mainstream applications as well.

  18. Subjective Evaluation of Audiovisual Signals

    Directory of Open Access Journals (Sweden)

    F. Fikejz

    2010-01-01

    Full Text Available This paper deals with subjective evaluation of audiovisual signals, with emphasis on the interaction between acoustic and visual quality. The subjective test is realized by a simple rating method. The audiovisual signal used in this test is a combination of images compressed by JPEG compression codec and sound samples compressed by MPEG-1 Layer III. Images and sounds have various contents. It simulates a real situation when the subject listens to compressed music and watches compressed pictures without the access to original, i.e. uncompressed signals.

  19. Information matching the content of visual working memory is prioritized for conscious access.

    Science.gov (United States)

    Gayet, Surya; Paffen, Chris L E; Van der Stigchel, Stefan

    2013-12-01

    Visual working memory (VWM) is used to retain relevant information for imminent goal-directed behavior. In the experiments reported here, we found that VWM helps to prioritize relevant information that is not yet available for conscious experience. In five experiments, we demonstrated that information matching VWM content reaches visual awareness faster than does information not matching VWM content. Our findings suggest a functional link between VWM and visual awareness: The content of VWM is recruited to funnel down the vast amount of sensory input to that which is relevant for subsequent behavior and therefore requires conscious access.

  20. 75 FR 28331 - Meaningful Access to United States Currency for Blind and Visually Impaired Persons

    Science.gov (United States)

    2010-05-20

    ... feature is used in some foreign currency, and the Study's data indicated that this feature was more... Currency for Blind and Visually Impaired Persons AGENCY: Bureau of Engraving and Printing, Department of... meaningful access to U.S. currency to people who are blind and visually impaired pursuant to section 504 of...

  1. The Correlation between Subjective and Objective Visual Function Test in Optic Neuropathy Patients

    Directory of Open Access Journals (Sweden)

    Ungsoo Kim

    2012-10-01

    Full Text Available Purpose: To investigate the correlation between visual acuity and quantitative measurements of visual evoked potentials (VEP, optical coherence tomography (OCT, and visual field test (VF in optic neuropathy patients. Methods: We evaluated 28 patients with optic neuropathy. Patients who had pale disc, visual acuity of less than 0.5 and abnormal visual field defect were included. At the first visit, we performed visual acuity and VF as subjective methods and OCT and VEP as objective methods. In the spectral domain OCT, rim volume, average and temporal quadrant retinal nerve fiber layer (RNFL thickness were measured. And pattern VEP (N75, P100, N135 latency, and P100 amplitude and Humphrey 24-2 visual field test (mean deviation and pattern standard deviation were obtained. Using Spearman's correlation coefficient, the correlation between visual acuity and various techniques were assessed. Results: Visual acuity was most correlated with the mean deviation of Humphrey perimetry.

  2. Causal role of prefrontal cortex in the threshold for access to consciousness.

    Science.gov (United States)

    Del Cul, A; Dehaene, S; Reyes, P; Bravo, E; Slachevsky, A

    2009-09-01

    What neural mechanisms support our conscious perception of briefly presented stimuli? Some theories of conscious access postulate a key role of top-down amplification loops involving prefrontal cortex (PFC). To test this issue, we measured the visual backward masking threshold in patients with focal prefrontal lesions, using both objective and subjective measures while controlling for putative attention deficits. In all conditions of temporal or spatial attention cueing, the threshold for access to consciousness was systematically shifted in patients, particular after a lesion of the left anterior PFC. The deficit affected subjective reports more than objective performance, and objective performance conditioned on subjective visibility was essentially normal. We conclude that PFC makes a causal contribution to conscious visual perception of masked stimuli, and outline a dual-route signal detection theory of objective and subjective decision making.

  3. What Is the Unit of Visual Attention? Object for Selection, but Boolean Map for Access

    Science.gov (United States)

    Huang, Liqiang

    2010-01-01

    In the past 20 years, numerous theories and findings have suggested that the unit of visual attention is the object. In this study, I first clarify 2 different meanings of unit of visual attention, namely the unit of access in the sense of measurement and the unit of selection in the sense of division. In accordance with this distinction, I argue…

  4. Wearing weighted backpack dilates subjective visual duration: The role of functional linkage between weight experience and visual timing

    Directory of Open Access Journals (Sweden)

    Lina eJia

    2015-09-01

    Full Text Available Bodily state plays a critical role in our perception. In the present study, we asked the question whether and how bodily experience of weights influences time perception. Participants judged durations of a picture (a backpack or a trolley bag presented on the screen, while wearing different weight backpacks or without backpack. The results showed that the subjective dura-tion of the backpack picture was dilated when participants wore a medium weighted backpack relative to an empty backpack or without backpack, regardless of identity (e.g., color of the visual backpack. However, the duration dilation was not manifested for the picture of trolley bag. These findings suggest that weight experience modulates visual duration estimation through the linkage between the wore backpack and to-be-estimated visual target. The con-gruent action affordance between the wore backpack and visual inputs plays a critical role in the functional linkage between inner experience and time perception. We interpreted our findings within the framework of embodied time perception.

  5. An Alternative Option to Dedicated Braille Notetakers for People with Visual Impairments: Universal Technology for Better Access

    Science.gov (United States)

    Hong, Sunggye

    2012-01-01

    Technology provides equal access to information and helps people with visual impairments to complete tasks more independently. Among various assistive technology options for people with visual impairments, braille notetakers have been considered the most significant because of their technological innovation. Braille notetakers allow users who are…

  6. Accessibility of Shared Space for visually impaired persons : An inventory in the Netherlands

    NARCIS (Netherlands)

    Havik, Else M; Melis - Dankers, Bart JM; Steyvers, Frank JJM; Kooijman, Aart C

    Shared Space is a concept that comprises the design and planning process of a public space. There are concerns about the accessibility of Shared Spaces for people who are visually impaired. This study provides a systematic overview of the appearance of Shared Spaces in the Netherlands and the

  7. Access NASA Satellite Global Precipitation Data Visualization on YouTube

    Science.gov (United States)

    Liu, Z.; Su, J.; Acker, J. G.; Huffman, G. J.; Vollmer, B.; Wei, J.; Meyer, D. J.

    2017-12-01

    Since the satellite era began, NASA has collected a large volume of Earth science observations for research and applications around the world. Satellite data at 12 NASA data centers can also be used for STEM activities such as disaster events, climate change, etc. However, accessing satellite data can be a daunting task for non-professional users such as teachers and students because of unfamiliarity of terminology, disciplines, data formats, data structures, computing resources, processing software, programing languages, etc. Over the years, many efforts have been developed to improve satellite data access, but barriers still exist for non-professionals. In this presentation, we will present our latest activity that uses the popular online video sharing web site, YouTube, to access visualization of global precipitation datasets at the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC). With YouTube, users can access and visualize a large volume of satellite data without necessity to learn new software or download data. The dataset in this activity is the 3-hourly TRMM (Tropical Rainfall Measuring Mission) Multi-satellite Precipitation Analysis (TMPA). The video consists of over 50,000 data files collected since 1998 onwards, covering a zone between 50°N-S. The YouTube video will last 36 minutes for the entire dataset record (over 19 years). Since the time stamp is on each frame of the video, users can begin at any time by dragging the time progress bar. This precipitation animation will allow viewing precipitation events and processes (e.g., hurricanes, fronts, atmospheric rivers, etc.) on a global scale. The next plan is to develop a similar animation for the GPM (Global Precipitation Measurement) Integrated Multi-satellitE Retrievals for GPM (IMERG). The IMERG provides precipitation on a near-global (60°N-S) coverage at half-hourly time interval, showing more details on precipitation processes and development, compared to the 3

  8. Cross-modal prediction changes the timing of conscious access during the motion-induced blindness.

    Science.gov (United States)

    Chang, Acer Y C; Kanai, Ryota; Seth, Anil K

    2015-01-01

    Despite accumulating evidence that perceptual predictions influence perceptual content, the relations between these predictions and conscious contents remain unclear, especially for cross-modal predictions. We examined whether predictions of visual events by auditory cues can facilitate conscious access to the visual stimuli. We trained participants to learn associations between auditory cues and colour changes. We then asked whether congruency between auditory cues and target colours would speed access to consciousness. We did this by rendering a visual target subjectively invisible using motion-induced blindness and then gradually changing its colour while presenting congruent or incongruent auditory cues. Results showed that the visual target gained access to consciousness faster in congruent than in incongruent trials; control experiments excluded potentially confounding effects of attention and motor response. The expectation effect was gradually established over blocks suggesting a role for extensive training. Overall, our findings show that predictions learned through cross-modal training can facilitate conscious access to visual stimuli. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Auditory and Visual Memory Span: Cognitive Processing by TMR Individuals with Down Syndrome or Other Etiologies.

    Science.gov (United States)

    Varnhagen, Connie K.; And Others

    1987-01-01

    Auditory and visual memory span were examined with 13 Down Syndrome and 15 other trainable mentally retarded young adults. Although all subjects demonstrated relatively poor auditory memory span, Down Syndrome subjects were especially poor at long-term memory access for visual stimulus identification and short-term storage and processing of…

  10. An Evaluation of a Computer-Based Training on the Visual Analysis of Single-Subject Data

    Science.gov (United States)

    Snyder, Katie

    2013-01-01

    Visual analysis is the primary method of analyzing data in single-subject methodology, which is the predominant research method used in the fields of applied behavior analysis and special education. Previous research on the reliability of visual analysis suggests that judges often disagree about what constitutes an intervention effect. Considering…

  11. Enabling Seamless Access to Digital Graphical Contents for Visually Impaired Individuals via Semantic-Aware Processing

    Directory of Open Access Journals (Sweden)

    Baoxin Li

    2007-11-01

    Full Text Available Vision is one of the main sources through which people obtain information from the world, but unfortunately, visually-impaired people are partially or completely deprived of this type of information. With the help of computer technologies, people with visual impairment can independently access digital textual information by using text-to-speech and text-to-Braille software. However, in general, there still exists a major barrier for people who are blind to access the graphical information independently in real-time without the help of sighted people. In this paper, we propose a novel multi-level and multi-modal approach aiming at addressing this challenging and practical problem, with the key idea being semantic-aware visual-to-tactile conversion through semantic image categorization and segmentation, and semantic-driven image simplification. An end-to-end prototype system was built based on the approach. We present the details of the approach and the system, report sample experimental results with realistic data, and compare our approach with current typical practice.

  12. Enabling Seamless Access to Digital Graphical Contents for Visually Impaired Individuals via Semantic-Aware Processing

    Directory of Open Access Journals (Sweden)

    Wang Zheshen

    2007-01-01

    Full Text Available Vision is one of the main sources through which people obtain information from the world, but unfortunately, visually-impaired people are partially or completely deprived of this type of information. With the help of computer technologies, people with visual impairment can independently access digital textual information by using text-to-speech and text-to-Braille software. However, in general, there still exists a major barrier for people who are blind to access the graphical information independently in real-time without the help of sighted people. In this paper, we propose a novel multi-level and multi-modal approach aiming at addressing this challenging and practical problem, with the key idea being semantic-aware visual-to-tactile conversion through semantic image categorization and segmentation, and semantic-driven image simplification. An end-to-end prototype system was built based on the approach. We present the details of the approach and the system, report sample experimental results with realistic data, and compare our approach with current typical practice.

  13. Comparison of visual outcomes and subjective visual quality after bilateral implantation of a diffractive trifocal intraocular lens and blended implantation of apodized diffractive bifocal intraocular lenses

    Directory of Open Access Journals (Sweden)

    Gundersen KG

    2016-05-01

    Full Text Available Kjell G Gundersen,1 Rick Potvin21IFocus Øyeklinikk AS, Haugesund, Norway; 2Science in Vision, Akron, NY, USAPurpose: To compare the visual acuity (VA and quality of vision between bilateral implantation of a trifocal intraocular lens (IOL and blended bifocal IOLs with an intermediate add in the dominant eye and a near add in the nondominant eye.Patients and methods: Patients with either trifocal or blended bifocal IOLs implanted were recruited after surgery. Subjects returned for a single diagnostic visit between 3 and 24 months after surgery. VA was tested at various distances, including low-contrast acuity and acuity at their preferred reading distance. A binocular defocus curve was obtained, and subjective visual function and quality of vision were evaluated.Results: Twenty-five trifocal subjects and 30 blended bifocal subjects were enrolled. There were no significant differences in low-contrast acuity, preferred reading distance, or acuity at that reading distance. Binocular vision at 4 m, 60 cm, and 40 cm was not statistically significantly different. The trifocal provided statistically significantly better visual acuity (P<0.05 at vergences from -0.5 to -1.5 D (from 2 m to 67 cm viewing distance, P<0.05. There was no statistically significant difference in the near vision subscale scores of the 39-question National Eye Institute Visual Function Questionnaire or the overall scores of the Quality of Vision questionnaire, though significantly more trifocal subjects reported that the observed visual disturbances were “bothersome” (P<0.05.Conclusion: Both lens modalities provided subjects with excellent binocular near and distance vision, with similar low rates of visual disturbances and good reported functional vision. The trifocal IOL provided significantly better intermediate VA in the viewing distance range of 2 m to 67 cm, corresponding to viewing things such as a car dashboard or grocery shelf. VA was similar between groups at

  14. J-TEXT WebScope: An efficient data access and visualization system for long pulse fusion experiment

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Wei, E-mail: zhenghaku@gmail.com [State Key Laboratory of Advanced Electromagnetic Engineering and Technology in Huazhong University of Science and Technology, Wuhan 430074 (China); School of Electrical and Electronic Engineering in Huazhong University of Science and Technology, Wuhan 430074 (China); Wan, Kuanhong; Chen, Zhi; Hu, Feiran; Liu, Qiang [State Key Laboratory of Advanced Electromagnetic Engineering and Technology in Huazhong University of Science and Technology, Wuhan 430074 (China); School of Electrical and Electronic Engineering in Huazhong University of Science and Technology, Wuhan 430074 (China)

    2016-11-15

    Highlights: • No matter how large the data is, the response time is always less than 500 milliseconds. • It is intelligent and just gives you the data you want. • It can be accessed directly over the Internet without installing special client software if you already have a browser. • Adopt scale and segment technology to organize data. • To support a new database for the WebScope is quite easy. • With the configuration stored in user’s profile, you have your own portable WebScope. - Abstract: Fusion research is an international collaboration work. To enable researchers across the world to visualize and analyze the experiment data, a web based data access and visualization tool is quite important [1]. Now, a new WebScope based on RIA (Rich Internet Application) is designed and implemented to meet these requirements. On the browser side, a fluent and intuitive interface is provided for researchers at J-TEXT laboratory and collaborators from all over the world to view experiment data and related metadata. The fusion experiments will feature long pulse and high sampling rate in the future. The data access and visualization system in this work has adopted segment and scale concept. Large data samples are re-sampled in different scales and then split into segments for instant response. It allows users to view extremely large data on the web browser efficiently, without worrying about the limitation on the size of the data. The HTML5 and JavaScript based web front-end can provide intuitive and fluent user experience. On the server side, a RESTful (Representational State Transfer) web API, which is based on ASP.NET MVC (Model View Controller), allows users to access the data and its metadata through HTTP (HyperText Transfer Protocol). An interface to the database has been designed to decouple the data access and visualization system from the data storage. It can be applied upon any data storage system like MDSplus or JTEXTDB, and this system is very easy to

  15. J-TEXT WebScope: An efficient data access and visualization system for long pulse fusion experiment

    International Nuclear Information System (INIS)

    Zheng, Wei; Wan, Kuanhong; Chen, Zhi; Hu, Feiran; Liu, Qiang

    2016-01-01

    Highlights: • No matter how large the data is, the response time is always less than 500 milliseconds. • It is intelligent and just gives you the data you want. • It can be accessed directly over the Internet without installing special client software if you already have a browser. • Adopt scale and segment technology to organize data. • To support a new database for the WebScope is quite easy. • With the configuration stored in user’s profile, you have your own portable WebScope. - Abstract: Fusion research is an international collaboration work. To enable researchers across the world to visualize and analyze the experiment data, a web based data access and visualization tool is quite important [1]. Now, a new WebScope based on RIA (Rich Internet Application) is designed and implemented to meet these requirements. On the browser side, a fluent and intuitive interface is provided for researchers at J-TEXT laboratory and collaborators from all over the world to view experiment data and related metadata. The fusion experiments will feature long pulse and high sampling rate in the future. The data access and visualization system in this work has adopted segment and scale concept. Large data samples are re-sampled in different scales and then split into segments for instant response. It allows users to view extremely large data on the web browser efficiently, without worrying about the limitation on the size of the data. The HTML5 and JavaScript based web front-end can provide intuitive and fluent user experience. On the server side, a RESTful (Representational State Transfer) web API, which is based on ASP.NET MVC (Model View Controller), allows users to access the data and its metadata through HTTP (HyperText Transfer Protocol). An interface to the database has been designed to decouple the data access and visualization system from the data storage. It can be applied upon any data storage system like MDSplus or JTEXTDB, and this system is very easy to

  16. Achievable Rate Estimation of IEEE 802.11ad Visual Big-Data Uplink Access in Cloud-Enabled Surveillance Applications.

    Science.gov (United States)

    Kim, Joongheon; Kim, Jong-Kook

    2016-01-01

    This paper addresses the computation procedures for estimating the impact of interference in 60 GHz IEEE 802.11ad uplink access in order to construct visual big-data database from randomly deployed surveillance camera sensing devices. The acquired large-scale massive visual information from surveillance camera devices will be used for organizing big-data database, i.e., this estimation is essential for constructing centralized cloud-enabled surveillance database. This performance estimation study captures interference impacts on the target cloud access points from multiple interference components generated by the 60 GHz wireless transmissions from nearby surveillance camera devices to their associated cloud access points. With this uplink interference scenario, the interference impacts on the main wireless transmission from a target surveillance camera device to its associated target cloud access point with a number of settings are measured and estimated under the consideration of 60 GHz radiation characteristics and antenna radiation pattern models.

  17. The use of mobile devices as assistive technology in resource-limited environments: access for learners with visual impairments in Kenya.

    Science.gov (United States)

    Foley, Alan R; Masingila, Joanna O

    2015-07-01

    In this paper, the authors explore the use of mobile devices as assistive technology for students with visual impairments in resource-limited environments. This paper provides initial data and analysis from an ongoing project in Kenya using tablet devices to provide access to education and independence for university students with visual impairments in Kenya. The project is a design-based research project in which we have developed and are refining a theoretically grounded intervention--a model for developing communities of practice to support the use of mobile technology as an assistive technology. We are collecting data to assess the efficacy and improve the model as well as inform the literature that has guided the design of the intervention. In examining the impact of the use of mobile devices for the students with visual impairments, we found that the devices provide the students with (a) access to education, (b) the means to participate in everyday life and (c) the opportunity to create a community of practice. Findings from this project suggest that communities of practice are both a viable and a valuable approach for facilitating the diffusion and support of mobile devices as assistive technology for students with visual impairments in resource-limited environments. Implications for Rehabilitation The use of mobile devices as assistive technology in resource-limited environments provides students with visual impairments access to education and enhanced means to participate in everyday life. Communities of practice are both a viable and a valuable approach for facilitating the diffusion and support of mobile devices as assistive technology for students with visual impairments in resource-limited environments. Providing access to assistive technology early and consistently throughout students' schooling builds both their skill and confidence and also demonstrates the capabilities of people with visual impairments to the larger society.

  18. Cognitive and functional patterns of nondemented subjects with equivocal visual amyloid PET findings

    International Nuclear Information System (INIS)

    Payoux, P.; Delrieu, J.; Gallini, A.; Cantet, C.; Voisin, T.; Gillette-Guyonnet, S.; Vellas, B.; Adel, D.; Salabert, A.S.; Hitzel, A.; Tafani, M.; Verbizier, D. de; Darcourt, J.; Fernandez, P.; Monteil, J.; Carrie, I.; Pontecorvo, M.; Andrieu, S.

    2015-01-01

    Despite good to excellent inter-reader agreement in the evaluation of amyloid load on PET scans in subjects with Alzheimer's disease, some equivocal findings have been reported in the literature. We aimed to describe the clinical characteristics of subjects with equivocal PET images. Nondemented subjects aged 70 years or more were enrolled from the MAPT trial. Cognitive and functional assessments were conducted at baseline, at 6 months, and annually for 3 years. During the follow-up period, 271 subjects had 18 F-AV45 PET scans. Images were visually assessed by three observers and classified as positive, negative or equivocal (if one observer disagreed). After debate, equivocal images were reclassified as positive (EP+) or negative (EP-). Scans were also classified by semiautomated quantitative analysis using mean amyloid uptake of cortical regions. We evaluated agreement among the observers, and between visual and quantitative assessments using kappa coefficients, and compared the clinical characteristics of the subjects according to their PET results. In 158 subjects (58.30 %) the PET scan was negative for amyloid, in 77 (28.41 %) the scan was positive and in 36 (13.28 %) the scan was equivocal. Agreement among the three observers was excellent (kappa 0.80). Subjects with equivocal images were more frequently men (58 % vs. 37 %) and exhibited intermediate scores on cognitive and functional scales between those of subjects with positive and negative scans. Amyloid load differed between the EP- and negative groups and between the EP+ and positive groups after reclassification. Equivocal amyloid PET images could represent a neuroimaging entity with intermediate amyloid load but without a specific neuropsychological pattern. Clinical follow-up to assess cognitive evolution in subjects with equivocal scans is needed. (orig.)

  19. Cognitive and functional patterns of nondemented subjects with equivocal visual amyloid PET findings

    Energy Technology Data Exchange (ETDEWEB)

    Payoux, P. [Purpan University Hospital, Department of Nuclear Medicine, CHU Toulouse, Toulouse (France); Inserm, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Universite de Toulouse, UPS, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); INSERM U825, CHU Purpan, Toulouse Cedex (France); Delrieu, J. [Purpan University Hospital, Gerontopole, Department of Geriatrics, CHU Toulouse, Toulouse (France); INSERM UMR 1027, Toulouse (France); Gallini, A.; Cantet, C.; Voisin, T.; Gillette-Guyonnet, S.; Vellas, B. [Universite de Toulouse, UPS, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Purpan University Hospital, Gerontopole, Department of Geriatrics, CHU Toulouse, Toulouse (France); INSERM UMR 1027, Toulouse (France); Adel, D.; Salabert, A.S. [Inserm, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Hitzel, A. [Purpan University Hospital, Department of Nuclear Medicine, CHU Toulouse, Toulouse (France); Universite de Toulouse, UPS, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Tafani, M. [Purpan University Hospital, Department of Nuclear Medicine, CHU Toulouse, Toulouse (France); Inserm, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Universite de Toulouse, UPS, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Verbizier, D. de [Montpellier University Hospital, Department of Nuclear Medicine, Montpellier (France); Darcourt, J. [Centre Antoine Lacassagne, Nuclear Medicine Department, Nice (France); University of Nice-Sophia Antipolis, Nice (France); Fernandez, P. [Pellegrin University Hospital Bordeaux, Nuclear Medicine Department, Bordeaux (France); University Bordeaux II, CNRS UMR 5287 - INCIA, Victor Segalen, Bordeaux (France); Monteil, J. [University Hospital, Department of Nuclear Medicine, Limoges (France); University of Limoges, Limoges (France); Carrie, I. [Purpan University Hospital, Gerontopole, Department of Geriatrics, CHU Toulouse, Toulouse (France); Pontecorvo, M. [Avid Radiopharmaceuticals, Philadelphia, PA (United States); Andrieu, S. [Universite de Toulouse, UPS, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Purpan University Hospital, Gerontopole, Department of Geriatrics, CHU Toulouse, Toulouse (France); INSERM UMR 1027, Toulouse (France); CHU Toulouse, Department of Epidemiology and Public Health, Toulouse (France)

    2015-08-15

    Despite good to excellent inter-reader agreement in the evaluation of amyloid load on PET scans in subjects with Alzheimer's disease, some equivocal findings have been reported in the literature. We aimed to describe the clinical characteristics of subjects with equivocal PET images. Nondemented subjects aged 70 years or more were enrolled from the MAPT trial. Cognitive and functional assessments were conducted at baseline, at 6 months, and annually for 3 years. During the follow-up period, 271 subjects had {sup 18}F-AV45 PET scans. Images were visually assessed by three observers and classified as positive, negative or equivocal (if one observer disagreed). After debate, equivocal images were reclassified as positive (EP+) or negative (EP-). Scans were also classified by semiautomated quantitative analysis using mean amyloid uptake of cortical regions. We evaluated agreement among the observers, and between visual and quantitative assessments using kappa coefficients, and compared the clinical characteristics of the subjects according to their PET results. In 158 subjects (58.30 %) the PET scan was negative for amyloid, in 77 (28.41 %) the scan was positive and in 36 (13.28 %) the scan was equivocal. Agreement among the three observers was excellent (kappa 0.80). Subjects with equivocal images were more frequently men (58 % vs. 37 %) and exhibited intermediate scores on cognitive and functional scales between those of subjects with positive and negative scans. Amyloid load differed between the EP- and negative groups and between the EP+ and positive groups after reclassification. Equivocal amyloid PET images could represent a neuroimaging entity with intermediate amyloid load but without a specific neuropsychological pattern. Clinical follow-up to assess cognitive evolution in subjects with equivocal scans is needed. (orig.)

  20. Intuitive tactile zooming for graphics accessed by individuals who are blind and visually impaired.

    Science.gov (United States)

    Rastogi, Ravi; Pawluk, T V Dianne; Ketchum, Jessica

    2013-07-01

    One possibility of providing access to visual graphics for those who are visually impaired is to present them tactually: unfortunately, details easily available to vision need to be magnified to be accessible through touch. For this, we propose an "intuitive" zooming algorithm to solve potential problems with directly applying visual zooming techniques to haptic displays that sense the current location of a user on a virtual diagram with a position sensor and, then, provide the appropriate local information either through force or tactile feedback. Our technique works by determining and then traversing the levels of an object tree hierarchy of a diagram. In this manner, the zoom steps adjust to the content to be viewed, avoid clipping and do not zoom when no object is present. The algorithm was tested using a small, "mouse-like" display with tactile feedback on pictures representing houses in a community and boats on a lake. We asked the users to answer questions related to details in the pictures. Comparing our technique to linear and logarithmic step zooming, we found a significant increase in the correctness of the responses (odds ratios of 2.64:1 and 2.31:1, respectively) and usability (differences of 36% and 19%, respectively) using our "intuitive" zooming technique.

  1. The Helioviewer Project: Browsing, Visualizing and Accessing Petabytes of Solar Data

    Science.gov (United States)

    Mueller, Daniel; Hughitt, V. K.; Langenberg, M.; Ireland, J.; Pagel, S.; Schmidt, L.; Garcia Ortiz, J. P.; Dimitoglou, G.; Fleck, B.

    2010-05-01

    After its successful launch, NASA's Solar Dynamics Observatory (SDO) will soon return more than 1 Terabyte worth of images per day. This unprecedented torrent of data will pose an entirely new set of challenges with respect to data access, data browsing and searching for interesting data while avoiding the proverbial search for "a needle in a haystack". In order to fully exploit SDO's wealth of data and connect it to data from other solar missions like SOHO, scientists need to be able to interactively browse and visualize many different data products spanning a large range of physical length and time scales. So far, all tools available to the scientific community either require downloading all potentially relevant data sets beforehand in their entirety or provide only movies with a fixed resolution and cadence. The Helioviewer project offers a solution to these challenges by providing a suite of tools that are based on the new JPEG 2000 compression standard and enable scientists and the general public alike to intuitively browse visualize and access petabytes of image data remotely: - JHelioviewer, a cross-platform application that offers movie streaming and real-time processing using the JPEG 2000 Interactive Protocol (JPIP) and OpenGL, as well as feature/event overlays. - helioviewer.org, a web-based image and feature/event browser. - Server-side services to stream movies of arbitrary spatial and temporal resolution in a region-of-interest and quality-progressive form, a JPEG 2000 image database and a feature/event server. All the services can be accessed through well-documented interfaces (APIs). - Code to convert images into JPEG 2000 format. This presentation will give an overview of the Helioviewer Project, illustrate new features and highlight the advantages of JPEG 2000 as a data format for solar physics that has the potential to revolutionize the way high-resolution image data are disseminated and analyzed.

  2. Achievable Rate Estimation of IEEE 802.11ad Visual Big-Data Uplink Access in Cloud-Enabled Surveillance Applications.

    Directory of Open Access Journals (Sweden)

    Joongheon Kim

    Full Text Available This paper addresses the computation procedures for estimating the impact of interference in 60 GHz IEEE 802.11ad uplink access in order to construct visual big-data database from randomly deployed surveillance camera sensing devices. The acquired large-scale massive visual information from surveillance camera devices will be used for organizing big-data database, i.e., this estimation is essential for constructing centralized cloud-enabled surveillance database. This performance estimation study captures interference impacts on the target cloud access points from multiple interference components generated by the 60 GHz wireless transmissions from nearby surveillance camera devices to their associated cloud access points. With this uplink interference scenario, the interference impacts on the main wireless transmission from a target surveillance camera device to its associated target cloud access point with a number of settings are measured and estimated under the consideration of 60 GHz radiation characteristics and antenna radiation pattern models.

  3. Effect of Colour of Object on Simple Visual Reaction Time in Normal Subjects

    Directory of Open Access Journals (Sweden)

    Sunita B. Kalyanshetti

    2014-01-01

    Full Text Available The measure of simple reaction time has been used to evaluate the processing speed of CNS and the co-ordination between the sensory and motor systems. As the reaction time is influenced by different factors; the impact of colour of objects in modulating the reaction time has been investigated in this study. 200 healthy volunteers (female gender 100 and male gender100 of age group 18-25 yrs were included as subjects. The subjects were presented with two visual stimuli viz; red and green light by using an electronic response analyzer. Paired‘t’ test for comparison of visual reaction time for red and green colour in male gender shows p value<0.05 whereas in female gender shows p<0.001. It was observed that response latency for red colour was lesser than that of green colour which can be explained on the basis of trichromatic theory.

  4. The Influence of Water Access in Subjective Well-Being: Some Evidence in Yucatan, Mexico

    Science.gov (United States)

    Guardiola, Jorge; Gonzalez-Gomez, Francisco; Grajales, Angel Lendechy

    2013-01-01

    The literature on happiness or subjective well-being has explored the determinants of happiness without taking into consideration the role that water plays. In this paper we attempt to draw attention to water in subjective well-being studies. Approximately one hundred million people do not have access to water. A lack of clean water causes…

  5. Gravity dependence of the effect of optokinetic stimulation on the subjective visual vertical.

    Science.gov (United States)

    Ward, Bryan K; Bockisch, Christopher J; Caramia, Nicoletta; Bertolini, Giovanni; Tarnutzer, Alexander Andrea

    2017-05-01

    Accurate and precise estimates of direction of gravity are essential for spatial orientation. According to Bayesian theory, multisensory vestibular, visual, and proprioceptive input is centrally integrated in a weighted fashion based on the reliability of the component sensory signals. For otolithic input, a decreasing signal-to-noise ratio was demonstrated with increasing roll angle. We hypothesized that the weights of vestibular (otolithic) and extravestibular (visual/proprioceptive) sensors are roll-angle dependent and predicted an increased weight of extravestibular cues with increasing roll angle, potentially following the Bayesian hypothesis. To probe this concept, the subjective visual vertical (SVV) was assessed in different roll positions (≤ ± 120°, steps = 30°, n = 10) with/without presenting an optokinetic stimulus (velocity = ± 60°/s). The optokinetic stimulus biased the SVV toward the direction of stimulus rotation for roll angles ≥ ± 30° ( P stimulation. Variability and optokinetic bias were correlated ( R 2 = 0.71, slope = 0.71, 95% confidence interval = 0.57-0.86). An optimal-observer model combining an optokinetic bias with vestibular input reproduced measured errors closely. These findings support the hypothesis of a weighted multisensory integration when estimating direction of gravity with optokinetic stimulation. Visual input was weighted more when vestibular input became less reliable, i.e., at larger roll-tilt angles. However, according to Bayesian theory, the variability of combined cues is always lower than the variability of each source cue. If the observed increase in variability, although nonsignificant, is true, either it must depend on an additional source of variability, added after SVV computation, or it would conflict with the Bayesian hypothesis. NEW & NOTEWORTHY Applying a rotating optokinetic stimulus while recording the subjective visual vertical in different whole body roll angles, we noted the optokinetic

  6. Data Lakes and Data Visualization: An Innovative Approach to Address the Challenges of Access to Health Care in Mississippi.

    Science.gov (United States)

    Krause, Denise D

    2015-01-01

    There are a variety of challenges to developing strategies to improve access to health care, but access to data is critical for effective evidence-based decision-making. Many agencies and organizations throughout Mississippi have been collecting quality health data for many years. However, those data have historically resided in data silos and have not been readily shared. A strategy was developed to build and coordinate infrastructure, capacity, tools, and resources to facilitate health workforce and population health planning throughout the state. Realizing data as the foundation upon which to build, the primary objective was to develop the capacity to collect, store, maintain, visualize, and analyze data from a variety of disparate sources -- with the ultimate goal of improving access to health care. Specific aims were to: 1) build a centralized data repository and scalable informatics platform, 2) develop a data management solution for this platform and then, 3) derive value from this platform by facilitating data visualization and analysis. A managed data lake was designed and constructed for health data from disparate sources throughout the state of Mississippi. A data management application was developed to log and track all data sources, maps and geographies, and data marts. With this informatics platform as a foundation, a variety of tools are used to visualize and analyze data. To illustrate, a web mapping application was developed to examine the health workforce geographically and attractive data visualizations and dynamic dashboards were created to facilitate health planning and research. Samples of data visualizations that aim to inform health planners and policymakers are presented. Many agencies and organizations throughout the state benefit from this platform. The overarching goal is that by providing timely, reliable information to stakeholders, Mississippians in general will experience improved access to quality care.

  7. Rapid Eye Movements (REMs) and visual dream recall in both congenitally blind and sighted subjects

    Science.gov (United States)

    Bértolo, Helder; Mestre, Tiago; Barrio, Ana; Antona, Beatriz

    2017-08-01

    Our objective was to evaluate rapid eye movements (REMs) associated with visual dream recall in sighted subjects and congenital blind. During two consecutive nights polysomnographic recordings were performed at subjects home. REMs were detected by visual inspection on both EOG channels (EOG-H, EOG-V) and further classified as occurring isolated or in bursts. Dream recall was defined by the existence of a dream report. The two groups were compared using t-test and also the two-way ANOVA and a post-hoc Fisher test (for the features diagnosis (blind vs. sighted) and dream recall (yes or no) as a function of time). The average of REM awakenings per subject and the recall ability were identical in both groups. CB had a lower REM density than CS; the same applied to REM bursts and isolated eye movements. In the two-way ANOVA, REM bursts and REM density were significantly different for positive dream recall, mainly for the CB group and for diagnosis; furthermore for both features significant results were obtained for the interaction of time, recall and diagnosis; the interaction of recall and time was however, stronger. In line with previous findings the data show that blind have lower REMs density. However the ability of dream recall in congenitally blind and sighted controls is identical. In both groups visual dream recall is associated with an increase in REM bursts and density. REM bursts also show differences in the temporal profile. REM visual dream recall is associated with increased REMs activity.

  8. Exploring interoperability: The advancements and challenges of improving data discovery, access, and visualization of scientific data through the NOAA Earth Information System (NEIS). (Invited)

    Science.gov (United States)

    Stewart, J.; Lynge, J.; Hackathorn, E.; MacDermaid, C.; Pierce, R.; Smith, J.

    2013-12-01

    Interoperability is a complex subject and often leads to different definitions in different environments. An interoperable framework of web services can improve the user experience by providing an interface for interaction with data regardless of it's format or physical location. This in itself improves accessibility to data, fosters data exploration and use, and provides a framework for new tools and applications. With an interoperable system you have: -- Data ready for action. Services model facilitates agile response to events. Services can be combined or reused quickly, upgraded or modified independently. -- Any data available through an interoperable framework can be operated on or combined with other data. Integrating standardized formats and access. -- New and existing systems have access to wide variety of data. Any new data added is easily incorporated with minimal changes required. The possibilities are limitless. The NOAA Earth Information System (NEIS) at the Earth System Research Laboratory (ESRL) is continuing research into an interoperable framework of layered services designed to facilitate the discovery, access, integration, visualization, and understanding of all NOAA (past, present, and future) data. An underlying philosophy of NEIS is to take advantage of existing off-the-shelf technologies and standards to minimize development of custom code allowing everyone to take advantage of the framework to meet these goals above. This framework, while built by NOAA are not limited to NOAA data or applications. Any other data available through similar services or applications that understand these standards can work interchangeably. Two major challenges are under active research at ESRL are data discoverability and fast access to big data. This presentation will provide an update on development of NEIS, including these challenges, the findings, and recommendations on what is needed for an interoperable system, as well as ongoing research activities

  9. Learning where to look: electrophysiological and behavioral indices of visual search in young and old subjects.

    Science.gov (United States)

    Looren de Jong, H; Kok, A; Woestenburg, J C; Logman, C J; Van Rooy, J C

    1988-06-01

    The present investigation explores the way young and elderly subjects use regularities in target location in a visual display to guide search for targets. Although both young and old subjects show efficient use of search strategies, slight but reliable differences in reaction times suggest decreased ability in the elderly to use complex cues. Event-related potentials were very different for the young and the old. In the young, P3 amplitudes were larger on trials where the rule that governed the location of the target became evident; this was interpreted as an effect of memory updating. Enhanced positive Slow Wave amplitude indicated uncertainty in random search conditions. Elderly subjects' P3 and SW, however, seemed unrelated to behavioral performance, and they showed a large negative Slow Wave at central and parietal sites to randomly located targets. The latter finding was tentatively interpreted as a sign of increased effort in the elderly to allocate attention in visual space. This pattern of behavioral and ERP results suggests that age-related differences in search tasks can be understood in terms of changes in the strategy of allocating visual attention.

  10. Tutoring math platform accessible for visually impaired people.

    Science.gov (United States)

    Maćkowski, Michał Sebastian; Brzoza, Piotr Franciszek; Spinczyk, Dominik Roland

    2018-04-01

    There are many problems with teaching and assessing impaired students in higher education, especially in technical science, where the knowledge is represented mostly by structural information like: math formulae, charts, graphs, etc. Developing e-learning platform for distance education solves this problem only partially due to the lack of accessibility for the blind. The proposed method is based on the decomposition of the typical mathematical exercise into a sequence of elementary sub-exercises. This allows for interactive resolving of math exercises and assessment of the correctness of exercise solutions at every stage. The presented methods were prepared and evaluated by visually impaired people and students. The article presents the accessible interactive tutoring platform for math teaching and assessment, and experience in exploring it. The results of conducted research confirm good understanding of math formulae described according to elaborated rules. Regardless of the level of complexity of the math formulae the level of math formulae understanding is higher for alternative structural description. The proposed solution enables alternative descriptions of math formulae. Based on the research results, the tool for computer-aided interactive learning of mathematics adapted to the needs of the blind has been designed, implemented and deployed as a platform for on-site and online and distance learning. The designed solution can be very helpful in overcoming many barriers that occur while teaching impaired students. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Performance of brain-damaged, schizophrenic, and normal subjects on a visual searching task.

    Science.gov (United States)

    Goldstein, G; Kyc, F

    1978-06-01

    Goldstein, Rennick, Welch, and Shelly (1973) reported on a visual searching task that generated 94.1% correct classifications when comparing brain-damaged and normal subjects, and 79.4% correct classifications when comparing brain-damaged and psychiatric patients. In the present study, representing a partial cross-validation with some modification of the test procedure, comparisons were made between brain-damaged and schizophrenic, and brain-damaged and normal subjects. There were 92.5% correct classifications for the brain-damaged vs normal comparison, and 82.5% correct classifications for the brain-damaged vs schizophrenic comparison.

  12. Data visualization methods, data visualization devices, data visualization apparatuses, and articles of manufacture

    Science.gov (United States)

    Turner, Alan E.; Crow, Vernon L.; Payne, Deborah A.; Hetzler, Elizabeth G.; Cook, Kristin A.; Cowley, Wendy E.

    2015-06-30

    Data visualization methods, data visualization devices, data visualization apparatuses, and articles of manufacture are described according to some aspects. In one aspect, a data visualization method includes accessing a plurality of initial documents at a first moment in time, first processing the initial documents providing processed initial documents, first identifying a plurality of first associations of the initial documents using the processed initial documents, generating a first visualization depicting the first associations, accessing a plurality of additional documents at a second moment in time after the first moment in time, second processing the additional documents providing processed additional documents, second identifying a plurality of second associations of the additional documents and at least some of the initial documents, wherein the second identifying comprises identifying using the processed initial documents and the processed additional documents, and generating a second visualization depicting the second associations.

  13. A subjective scheduler for subjective dedicated networks

    Science.gov (United States)

    Suherman; Fakhrizal, Said Reza; Al-Akaidi, Marwan

    2017-09-01

    Multiple access technique is one of important techniques within medium access layer in TCP/IP protocol stack. Each network technology implements the selected access method. Priority can be implemented in those methods to differentiate services. Some internet networks are dedicated for specific purpose. Education browsing or tutorial video accesses are preferred in a library hotspot, while entertainment and sport contents could be subjects of limitation. Current solution may use IP address filter or access list. This paper proposes subjective properties of users or applications are used for priority determination in multiple access techniques. The NS-2 simulator is employed to evaluate the method. A video surveillance network using WiMAX is chosen as the object. Subjective priority is implemented on WiMAX scheduler based on traffic properties. Three different traffic sources from monitoring video: palace, park, and market are evaluated. The proposed subjective scheduler prioritizes palace monitoring video that results better quality, xx dB than the later monitoring spots.

  14. Book4All: A Tool to Make an e-Book More Accessible to Students with Vision/Visual-Impairments

    Science.gov (United States)

    Calabrò, Antonello; Contini, Elia; Leporini, Barbara

    Empowering people who are blind or otherwise visually impaired includes ensuring that products and electronic materials incorporate a broad range of accessibility features and work well with screen readers and other assistive technology devices. This is particularly important for students with vision impairments. Unfortunately, authors and publishers often do not include specific criteria when preparing the contents. Consequently, e-books can be inadequate for blind and low vision users, especially for students. In this paper we describe a semi-automatic tool developed to support operators who adapt e-documents for visually impaired students. The proposed tool can be used to convert a PDF e-book into a more suitable accessible and usable format readable on desktop computer or on mobile devices.

  15. Improving Access to Accommodations: Reducing Political and Institutional Barriers for Canadian Postsecondary Students with Visual Impairments

    Science.gov (United States)

    Ostrowski, Christopher P.

    2016-01-01

    Challenges to obtaining quality academic accommodations for students with visual impairments in postsecondary education hinder accessibility and the success of such students. The limitations of current policies and practices intended to address the needs of students in Canada are examined and potential solutions are discussed. Further systemic…

  16. Extraction of retinal tacks from subjects implanted with an epiretinal visual prosthesis.

    Science.gov (United States)

    de Juan, Eugene; Spencer, Rand; Barale, Pierre-Olivier; da Cruz, Lyndon; Neysmith, Jordan

    2013-10-01

    Retinal tacks, first developed for the treatment of complex retinal detachments, have more recently been used for the fixation of epiretinal electrode arrays as part of implanted visual prostheses. Here, we report on the clinical experience of extracting four such tacks after chronic implantation. The ability to safely extract retinal tacks ensures that epiretinal devices can be repositioned or removed if necessary. Custom-built, titanium alloy retinal tacks were mechanically removed from the posterior coats after prolonged implantation (up to 19 months). The resulting wound was characterized by clinical evaluation, fundus photography, and fluorescein angiography while being monitored for stability over time. The wounds were also compared to earlier published reports of the healing response around retinal tacks in human subjects. Tack extraction was accomplished successfully, without complication, in all four subjects. The wound site was readily identified by pale scar tissue. No change in the wound size or appearance was noted over many months of post-operative observation (up to 22 months after explant). No adverse effects on overall ocular health were detected. Extraction of retinal tacks from subjects implanted with epiretinal prostheses can be performed without significant complication. The long-term healing response appears to be stable and localized in eyes afflicted with retinitis pigmentosa or choroideremia. There was also minimal, if any, impact on the local circulatory system. These cases suggest that the use of retinal tacks for anchoring epiretinal visual prostheses does not preclude safe repositioning or removal of the device more than a year after implant.

  17. New orientation and accessibility option for persons with visual impairment: transportation applications for remote infrared audible signage.

    Science.gov (United States)

    Crandall, William; Bentzen, Billie Louise; Myers, Linda; Brabyn, John

    2001-05-01

    BACKGROUND: For a blind or visually impaired person, a vital prerequisite to accessing any feature of the built environment is being able to find this feature. Braille signs, even where available, do not replace the functions of print signage because they cannot be read from a distance. Remotely readable infrared signs utilise spoken infrared message transmissions to label key environmental features, so that a blind person with a suitable receiver can locate and identify them from a distance. METHODS: Three problems that are among the most challenging and dangerous faced by blind travellers are negotiating complex transit stations, locating bus stops and safely and efficiently crossing light-controlled intersections. We report the results of human factors studies using a remote infrared audible sign system (RIAS), Talking Signs(R), in these critical tasks, examining issues such as the amount of training needed to use the system, its impact on performance and safety, benefits for different population subgroups and user opinions of its value. RESULTS: Results are presented in the form of both objective performance measures and in subjects' ratings of the usefulness of the system in performing these tasks. Findings are that blind people can quickly and easily learn to use remote infrared audible signage effectively and that its use improves travel safety, efficiency and independence.? CONCLUSIONS: The technology provides equal access to a wide variety of public facilities.

  18. Accessing forgotten memory traces from long-term memory via visual movements

    Directory of Open Access Journals (Sweden)

    Estela eCamara

    2014-11-01

    Full Text Available Because memory retrieval often requires overt responses, it is difficult to determine to what extend forgetting occurs as a problem in explicit accessing of long-term memory traces. In this study, we used eye-tracking measures in combination with a behavioural task that favoured high forgetting rates to investigate the existence of memory traces from long-term memory in spite of failure in accessing them consciously. In 2 experiments, participants were encouraged to encode a large set of sound-picture-location associations. In a later test, sounds were presented and participants were instructed to visually scan, before a verbal memory report, for the correct location of the associated pictures in an empty screen. We found the reactivation of associated memories by sound cues at test biased oculomotor behaviour towards locations congruent with memory representations, even when participants failed to consciously provide a memory report of it. These findings reveal the emergence of a memory-guided behaviour that can be used to map internal representations of forgotten memories from long-term memory.

  19. Non-visual Interfaces and Network Games for Blind Users

    OpenAIRE

    Ina, Satoshi

    2002-01-01

    Visually impaired people have difficulty with communication of graphical information. It is to be more difficult for them to work/play in cooperation with sighted people at a distance. We developed a non-visual access method to a graphical screen through tactile and auditory sense, and applied it into network board/card games as a joint workspace for blind and sighted users via communication of image, sound, and voice. We took an "IGO" type boardgame and a Card game "SEVENS" as sample subject...

  20. Subject Access Problems of Different Types of OPAC Users Or, the Double Challenge.

    Science.gov (United States)

    Cochrane, Pauline A.

    1989-01-01

    Reviews the problems of users of online public access catalogs and argues that it is necessary to think of all searching problems as systems problems rather than user failures, and to concentrate research in the area of systems enhancements. A list of improved tools needed for subject searching in online catalogs is identified. (CLB)

  1. 論線上目錄之主題檢索 Subject Access in Online Catalog

    Directory of Open Access Journals (Sweden)

    Ming-Yueh Tsay

    1995-09-01

    Full Text Available 無This paper first (describes the current clevelopments of online catalog subject access. In particular, it emphasizes the application of DDC, LCC and LCSH for retrieving subject information through online catalogs. Subsequently, studies in the literature on enhancements to the above subject searching as well as keywords or phrases extracted from the bibliographic record are discussed. Finally, an overall pictures of online catalog which is under the Internet environment and some directions in which the future online catalog should evolve are provided.

  2. Factors Associated with Visual Fatigue from Curved Monitor Use: A Prospective Study of Healthy Subjects.

    Directory of Open Access Journals (Sweden)

    Haeng Jin Lee

    Full Text Available To investigate the factors associated with visual fatigue using monitors with various radii of curvature.Twenty normal healthy adults (8 men, 12 women; mean age, 26.2 ± 2.5 years prospectively watched five types of monitors including flat, 4000R, 3000R, 2000R, and 1000R curved monitors for 30 min. An experienced examiner measured the ophthalmological factors including near point of accommodation (NPA, near point of convergence (NPC, refraction, parameters during pupil response at light and saccadic movement just before and after the visual tasks. The questionnaires about subjective ocular symptoms were also investigated just before and after the visual tasks.The NPA increased after the visual tasks with a flat monitor compared with the curved monitors, with the 1000R curved monitor showing the smallest change (p = 0.020. The NPC increased for every monitor after the visual tasks; the largest increase occurred with the flat monitor (p = 0.001. There was no difference in refractive error, pupil response, or saccadic movement in the comparison of before and after the visual tasks. Among the nine factors in the questionnaire, the score of "eye pain" was significantly higher for the flat monitor versus the 1000R curved monitor after the visual tasks (p = 0.034.We identified NPA, NPC, and eye pain as factors associated with visual fatigue. Also, the curvature of the monitor was related to the visual fatigue.

  3. Museum activities in dementia care: Using visual analog scales to measure subjective wellbeing.

    Science.gov (United States)

    Johnson, Joana; Culverwell, Alison; Hulbert, Sabina; Robertson, Mitch; Camic, Paul M

    2017-07-01

    Introduction Previous research has shown that people with dementia and caregivers derive wellbeing-related benefits from viewing art in a group, and that facilitated museum object handling is effective in increasing subjective wellbeing for people with a range of health conditions. The present study quantitatively compared the impact of two museum-based activities and a social activity on the subjective wellbeing of people with dementia and their caregivers. Methods A quasi-experimental crossover design was used. People with early to middle stage dementia and caregivers ( N = 66) participated in museum object handling, a refreshment break, and art viewing in small groups. Visual analog scales were used to rate subjective wellbeing pre and post each activity. Results Mixed-design analysis of variances indicated wellbeing significantly increased during the session, irrespective of the order in which the activities were presented. Wellbeing significantly increased from object handling and art viewing for those with dementia and caregivers across pooled orders, but did not in the social activity of a refreshment break. An end-of-intervention questionnaire indicated that experiences of the session were positive. Conclusion Results provide a rationale for considering museum activities as part of a broader psychosocial, relational approach to dementia care and support the use of easy to administer visual analog scales as a quantitative outcome measure. Further partnership working is also supported between museums and healthcare professionals in the development of nonclinical, community-based programs for this population.

  4. Experimental Study on Subjective Evaluation for Visual Information by Event-Related Potential: Evaluation of Food and its Appearance

    Directory of Open Access Journals (Sweden)

    Motoshi Tanaka

    2011-10-01

    Full Text Available Evaluating subjective judgment for visual information by event-related potential (ERP quantitatively was studied. Pictures of food were displayed as visual information. And P300 component of the ERP was focused. The P300 is related to cognition and/or judgment, and has the latency in the range from 250 to 500 ms. As a fundamental study, the ERP was measured when subjectively judging food and its appearance by three-grade scale with the opinion “like”, “favorite” and “more favorite”. Sushi and cooked rice were selected as typical foods. And bottles which had almost the same shape without labels, but the colors were different, were used for an opinion test of the food appearance. Five pictures for each food were chosen by subjects before measurements. And no food which the subjects disliked was chosen because almost the same P300 amplitude appeared in both cases where the subjects judged as “like” and “dislike”. In results, the P300 amplitude by each subject's opinion was different, and the P300 area (surrounded by ERP waveform from the latency 250 to 500 ms became larger when the subjects judged as “more favorite”. These results indicate the feasibility of quantitative evaluation of subjective judgment by the ERP.

  5. Understanding and Improving Blind Students' Access to Visual Information in Computer Science Education

    Science.gov (United States)

    Baker, Catherine M.

    Teaching people with disabilities tech skills empowers them to create solutions to problems they encounter and prepares them for careers. However, computer science is typically taught in a highly visual manner which can present barriers for people who are blind. The goal of this dissertation is to understand and decrease those barriers. The first projects I present looked at the barriers that blind students face. I first present the results of my survey and interviews with blind students with degrees in computer science or related fields. This work highlighted the many barriers that these blind students faced. I then followed-up on one of the barriers mentioned, access to technology, by doing a preliminary accessibility evaluation of six popular integrated development environments (IDEs) and code editors. I found that half were unusable and all had some inaccessible portions. As access to visual information is a barrier in computer science education, I present three projects I have done to decrease this barrier. The first project is Tactile Graphics with a Voice (TGV). This project investigated an alternative to Braille labels for those who do not know Braille and showed that TGV was a potential alternative. The next project was StructJumper, which created a modified abstract syntax tree that blind programmers could use to navigate through code with their screen reader. The evaluation showed that users could navigate more quickly and easily determine the relationships of lines of code when they were using StructJumper compared to when they were not. Finally, I present a tool for dynamic graphs (the type with nodes and edges) which had two different modes for handling focus changes when moving between graphs. I found that the modes support different approaches for exploring the graphs and therefore preferences are mixed based on the user's preferred approach. However, both modes had similar accuracy in completing the tasks. These projects are a first step towards

  6. DDC in DSpace: Integration of Multi-lingual Subject Access System in Institutional Digital Repositories

    Directory of Open Access Journals (Sweden)

    Bijan Kumar Roy

    2017-12-01

    Full Text Available The paper discusses the nature of Knowledge Organization Systems (KOSs and shows how these can support digital library users. It demonstrates processes related to integration of KOS like the Dewey Decimal Classification, 22nd edition (DDC22 in DSpace software (http://www.dspace.org/ for organizing and retrieving (browsing and searching scholarly objects. An attempt has been made to use the DDC22 available in Bengali language and highlights the required mechanisms for system-level integration. It may help repository administrator to build IDR (Institutional Digital Repository integrated with SKOS-enabled multilingual subject access systems for supporting subject descriptors based indexing (DC.Subject metadata element, structured navigation (browsing and efficient searching.

  7. High School Teachers' Perspectives on Supporting Students with Visual Impairments toward Higher Education: Access, Barriers, and Success

    Science.gov (United States)

    Reed, Maureen; Curtis, Kathryn

    2011-01-01

    The objective of the study presented here was to understand the experiences of teachers in assisting students with visual impairments in making the transition to higher education. The teachers reported barriers in high school that affect students' access to and success in higher education. Furthermore, institutions of higher education provided…

  8. Interactive effects of carbon footprint information and its accessibility on value and subjective qualities of food products.

    Science.gov (United States)

    Kimura, Atsushi; Wada, Yuji; Kamada, Akiko; Masuda, Tomohiro; Okamoto, Masako; Goto, Sho-ichi; Tsuzuki, Daisuke; Cai, Dongsheng; Oka, Takashi; Dan, Ippeita

    2010-10-01

    We aimed to explore the interactive effects of the accessibility of information and the degree of carbon footprint score on consumers' value judgments of food products. Participants (n=151, undergraduate students in Japan) rated their maximum willingness to pay (WTP) for four food products varying in information accessibility (active-search or read-only conditions) and in carbon footprint values (low, middle, high, or non-display) provided. We also assessed further effects of information accessibly and carbon footprint value on other product attributes utilizing the subjective estimation of taste, quality, healthiness, and environmental friendliness. Results of the experiment demonstrated an interactive effect of information accessibility and the degree of carbon emission on consumer valuation of carbon footprint-labeled food. The carbon footprint value had a stronger impact on participants' WTP in the active-search condition than in the read-only condition. Similar to WTP, the results of the subjective ratings for product qualities also exhibited an interactive effect of the two factors on the rating of environmental friendliness for products. These results imply that the perceived environmental friendliness inferable from a carbon footprint label contributes to creating value for a food product.

  9. Nobody Can See Atoms: Science Camps Highlighting Approaches for Making Chemistry Accessible to Blind and Visually Impaired Students

    Science.gov (United States)

    Wedler, Henry B.; Boyes, Lee; Davis, Rebecca L.; Flynn, Dan; Franz, Annaliese; Hamann, Christian S.; Harrison, Jason G.; Lodewyk, Michael W.; Milinkevich, Kristin A.; Shaw, Jared T.; Tantillo, Dean J.; Wang, Selina C.

    2014-01-01

    Curricula for three chemistry camp experiences for blind and visually impaired (BVI) individuals that incorporated single- and multiday activities and experiments accessible to BVI students are described. Feedback on the camps from students, mentors, and instructors indicates that these events allowed BVI students, who in many cases have been…

  10. A Comparison of Keyword Subject Searching on Six British University OPACs Online Public Access Catalogs.

    Science.gov (United States)

    Aanonson, John

    1987-01-01

    Compares features of online public access catalogs (OPACs) at six British universities: (1) Cambridge; (2) Hull; (3) Newcastle; (4) Surrey; (5) Sussex; and (6) York. Results of keyword subject searches on two topics performed on each of the OPACs are reported and compared. Six references are listed. (MES)

  11. TheCellMap.org: A Web-Accessible Database for Visualizing and Mining the Global Yeast Genetic Interaction Network.

    Science.gov (United States)

    Usaj, Matej; Tan, Yizhao; Wang, Wen; VanderSluis, Benjamin; Zou, Albert; Myers, Chad L; Costanzo, Michael; Andrews, Brenda; Boone, Charles

    2017-05-05

    Providing access to quantitative genomic data is key to ensure large-scale data validation and promote new discoveries. TheCellMap.org serves as a central repository for storing and analyzing quantitative genetic interaction data produced by genome-scale Synthetic Genetic Array (SGA) experiments with the budding yeast Saccharomyces cerevisiae In particular, TheCellMap.org allows users to easily access, visualize, explore, and functionally annotate genetic interactions, or to extract and reorganize subnetworks, using data-driven network layouts in an intuitive and interactive manner. Copyright © 2017 Usaj et al.

  12. Flow visualization

    CERN Document Server

    Merzkirch, Wolfgang

    1974-01-01

    Flow Visualization describes the most widely used methods for visualizing flows. Flow visualization evaluates certain properties of a flow field directly accessible to visual perception. Organized into five chapters, this book first presents the methods that create a visible flow pattern that could be investigated by visual inspection, such as simple dye and density-sensitive visualization methods. It then deals with the application of electron beams and streaming birefringence. Optical methods for compressible flows, hydraulic analogy, and high-speed photography are discussed in other cha

  13. Barriers to accessing eye care services among visually impaired populations in rural Andhra Pradesh, South India

    Directory of Open Access Journals (Sweden)

    Kovai Vilas

    2007-01-01

    Full Text Available Purpose: To understand the reasons why people in rural south India with visual impairment arising from various ocular diseases do not seek eye care. Materials and Methods: A total of 5,573 persons above the age of 15 were interviewed and examined in the South Indian state of Andhra Pradesh covering the districts of Adilabad, West Godavari and Mahaboobnagar. A pre-tested structured questionnaire on barriers to eye care was administered by trained field investigators. Results: Of the eligible subjects, 1234 (22.1%, N=5573 presented with distant visual acuity < 20/60 or equivalent visual field loss in the better eye. Of these, 898 (72.7%, N=1234 subjects had not sought treatment despite noticing a decrease in vision citing personal, economic and social reasons. The analysis also showed that the odds of seeking treatment was significantly higher for literates [odds ratio (OR 1.91, 95% confidence interval (CI 1.38 to 2.65], for those who would be defined as blind by visual acuity category (OR 1.35, 95% CI 0.96 to 1.90 and for those with cataract and other causes of visual impairment (OR 1.50, 95% CI 1.11 to 2.03. Barriers to seeking treatment among those who had not sought treatment despite noticing a decrease in vision over the past five years were personal in 52% of the respondents, economic in 37% and social in 21%. Conclusion: Routine planning for eye care services in rural areas of India must address the barriers to eye care perceived by communities to increase the utilization of services.

  14. Use of Sine Shaped High-Frequency Rhythmic Visual Stimuli Patterns for SSVEP Response Analysis and Fatigue Rate Evaluation in Normal Subjects

    Directory of Open Access Journals (Sweden)

    Ahmadreza Keihani

    2018-05-01

    Full Text Available Background: Recent EEG-SSVEP signal based BCI studies have used high frequency square pulse visual stimuli to reduce subjective fatigue. However, the effect of total harmonic distortion (THD has not been considered. Compared to CRT and LCD monitors, LED screen displays high-frequency wave with better refresh rate. In this study, we present high frequency sine wave simple and rhythmic patterns with low THD rate by LED to analyze SSVEP responses and evaluate subjective fatigue in normal subjects.Materials and Methods: We used patterns of 3-sequence high-frequency sine waves (25, 30, and 35 Hz to design our visual stimuli. Nine stimuli patterns, 3 simple (repetition of each of above 3 frequencies e.g., P25-25-25 and 6 rhythmic (all of the frequencies in 6 different sequences e.g., P25-30-35 were chosen. A hardware setup with low THD rate (<0.1% was designed to present these patterns on LED. Twenty two normal subjects (aged 23–30 (25 ± 2.1 yrs were enrolled. Visual analog scale (VAS was used for subjective fatigue evaluation after presentation of each stimulus pattern. PSD, CCA, and LASSO methods were employed to analyze SSVEP responses. The data including SSVEP features and fatigue rate for different visual stimuli patterns were statistically evaluated.Results: All 9 visual stimuli patterns elicited SSVEP responses. Overall, obtained accuracy rates were 88.35% for PSD and > 90% for CCA and LASSO (for TWs > 1 s. High frequency rhythmic patterns group with low THD rate showed higher accuracy rate (99.24% than simple patterns group (98.48%. Repeated measure ANOVA showed significant difference between rhythmic pattern features (P < 0.0005. Overall, there was no significant difference between the VAS of rhythmic [3.85 ± 2.13] compared to the simple patterns group [3.96 ± 2.21], (P = 0.63. Rhythmic group had lower within group VAS variation (min = P25-30-35 [2.90 ± 2.45], max = P35-25-30 [4.81 ± 2.65] as well as least individual pattern VAS (P25

  15. Assessment of visual disability using visual evoked potentials.

    Science.gov (United States)

    Jeon, Jihoon; Oh, Seiyul; Kyung, Sungeun

    2012-08-06

    The purpose of this study is to validate the use of visual evoked potential (VEP) to objectively quantify visual acuity in normal and amblyopic patients, and determine if it is possible to predict visual acuity in disability assessment to register visual pathway lesions. A retrospective chart review was conducted of patients diagnosed with normal vision, unilateral amblyopia, optic neuritis, and visual disability who visited the university medical center for registration from March 2007 to October 2009. The study included 20 normal subjects (20 right eyes: 10 females, 10 males, ages 9-42 years), 18 unilateral amblyopic patients (18 amblyopic eyes, ages 19-36 years), 19 optic neuritis patients (19 eyes: ages 9-71 years), and 10 patients with visual disability having visual pathway lesions. Amplitude and latencies were analyzed and correlations with visual acuity (logMAR) were derived from 20 normal and 18 amblyopic subjects. Correlation of VEP amplitude and visual acuity (logMAR) of 19 optic neuritis patients confirmed relationships between visual acuity and amplitude. We calculated the objective visual acuity (logMAR) of 16 eyes from 10 patients to diagnose the presence or absence of visual disability using relations derived from 20 normal and 18 amblyopic eyes. Linear regression analyses between amplitude of pattern visual evoked potentials and visual acuity (logMAR) of 38 eyes from normal (right eyes) and amblyopic (amblyopic eyes) subjects were significant [y = -0.072x + 1.22, x: VEP amplitude, y: visual acuity (logMAR)]. There were no significant differences between visual acuity prediction values, which substituted amplitude values of 19 eyes with optic neuritis into function. We calculated the objective visual acuity of 16 eyes of 10 patients to diagnose the presence or absence of visual disability using relations of y = -0.072x + 1.22 (-0.072). This resulted in a prediction reference of visual acuity associated with malingering vs. real

  16. Electrophysiological assessment of the time course of bilingual visual word recognition: Early access to language membership.

    Science.gov (United States)

    Yiu, Loretta K; Pitts, Michael A; Canseco-Gonzalez, Enriqueta

    2015-08-01

    Previous research examining the time course of lexical access during word recognition suggests that phonological processing precedes access to semantic information, which in turn precedes access to syntactic information. Bilingual word recognition likely requires an additional level: knowledge of which language a specific word belongs to. Using the recording of event-related potentials, we investigated the time course of access to language membership information relative to semantic (Experiment 1) and syntactic (Experiment 2) encoding during visual word recognition. In Experiment 1, Spanish-English bilinguals viewed a series of printed words while making dual-choice go/nogo and left/right hand decisions based on semantic (whether the word referred to an animal or an object) and language membership information (whether the word was in English or in Spanish). Experiment 2 used a similar paradigm but with syntactic information (whether the word was a noun or a verb) as one of the response contingencies. The onset and peak latency of the N200, a component related to response inhibition, indicated that language information is accessed earlier than semantic information. Similarly, language information was also accessed earlier than syntactic information (but only based on peak latency). We discuss these findings with respect to models of bilingual word recognition and language comprehension in general. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Contrast and strength of visual memory and imagery differentially affect visual perception.

    Science.gov (United States)

    Saad, Elyana; Silvanto, Juha

    2013-01-01

    Visual short-term memory (VSTM) and visual imagery have been shown to modulate visual perception. However, how the subjective experience of VSTM/imagery and its contrast modulate this process has not been investigated. We addressed this issue by asking participants to detect brief masked targets while they were engaged either in VSTM or visual imagery. Subjective experience of memory/imagery (strength scale), and the visual contrast of the memory/mental image (contrast scale) were assessed on a trial-by-trial basis. For both VSTM and imagery, contrast of the memory/mental image was positively associated with reporting target presence. Consequently, at the sensory level, both VSTM and imagery facilitated visual perception. However, subjective strength of VSTM was positively associated with visual detection whereas the opposite pattern was found for imagery. Thus the relationship between subjective strength of memory/imagery and visual detection are qualitatively different for VSTM and visual imagery, although their impact at the sensory level appears similar. Our results furthermore demonstrate that imagery and VSTM are partly dissociable processes.

  18. Contrast and strength of visual memory and imagery differentially affect visual perception.

    Directory of Open Access Journals (Sweden)

    Elyana Saad

    Full Text Available Visual short-term memory (VSTM and visual imagery have been shown to modulate visual perception. However, how the subjective experience of VSTM/imagery and its contrast modulate this process has not been investigated. We addressed this issue by asking participants to detect brief masked targets while they were engaged either in VSTM or visual imagery. Subjective experience of memory/imagery (strength scale, and the visual contrast of the memory/mental image (contrast scale were assessed on a trial-by-trial basis. For both VSTM and imagery, contrast of the memory/mental image was positively associated with reporting target presence. Consequently, at the sensory level, both VSTM and imagery facilitated visual perception. However, subjective strength of VSTM was positively associated with visual detection whereas the opposite pattern was found for imagery. Thus the relationship between subjective strength of memory/imagery and visual detection are qualitatively different for VSTM and visual imagery, although their impact at the sensory level appears similar. Our results furthermore demonstrate that imagery and VSTM are partly dissociable processes.

  19. A visual test based on a freeware software for quantifying and displaying night-vision disturbances: study in subjects after alcohol consumption.

    Science.gov (United States)

    Castro, José J; Ortiz, Carolina; Pozo, Antonio M; Anera, Rosario G; Soler, Margarita

    2014-05-07

    In this work, we propose the Halo test, a simple visual test based on a freeware software for quantifying and displaying night-vision disturbances perceived by subjects under different experimental conditions, more precisely studying the influence of the alcohol consumption on visual function. In the Halo test, viewed on a monitor, the subject's task consists of detecting luminous peripheral stimuli around a central high-luminance stimulus over a dark background. The test, performed by subjects before and after consuming alcoholic drinks, which deteriorate visual performance, evaluates the influence that alcohol consumption exerts on the visual-discrimination capacity under low illumination conditions. Measurements were made monocularly and binocularly. Pupil size was also measured in both conditions (pre/post). Additionally, we used a double-pass device to measure objectively the optical-quality of the eye and corroborate the results from the Halo test. We found a significant deterioration of the discrimination capacity after alcohol consumption, indicating that the higher the breath-alcohol content, the greater the deterioration of the visual-discrimination capacity. After alcohol intake, the graphical results showed a greater area of undetected peripheral stimuli around the central high-luminance stimulus. An enlargement of the pupil was also observed and the optical quality of the eye was deteriorated after alcohol consumption. A greater influence of halos and other night-vision disturbances were reported with the Halo test after alcohol consumption. The Halo freeware software constitutes a positive contribution for evaluating nighttime visual performance in clinical applications, such as reported here, but also in patients after refractive surgery (where halos are present) or for monitoring (time course) some ocular pathologies under pharmacological treatment.

  20. Accessibility observations of visually impaired users using the South African National Accessibility Portal

    CSIR Research Space (South Africa)

    Coetzee, L

    2008-05-01

    Full Text Available . Improving web site accessibility has proven to be a challenging task with a myriad of standards, accessibility testing tools and few technical guides for implementation. This paper presents the South African National Accessibility Portal (NAP), which is used...

  1. The difference in subjective and objective complexity in the visual short-term memory

    DEFF Research Database (Denmark)

    Dall, Jonas Olsen; Sørensen, Thomas Alrik

    Several studies discuss the influence of complexity on the visual short term memory; some have demonstrated that short-term memory is surprisingly stable regardless of content (e.g. Luck & Vogel, 1997) where others have shown that memory can be influenced by the complexity of stimulus (e.g. Alvarez...... characters. On the contrary expertise or word frequency may reflect what could be termed subjective complexity, as this relate directly to the individual mental categories established. This study will be able to uncover more details on how we should define complexity of objects to be encoded into short-term....... & Cavanagh, 2004). But the term complexity is often not clearly defined. Sørensen (2008; see also Dall, Katsumi, & Sørensen, 2016) suggested that complexity can be related to two different types; objective and subjective complexity. This distinction is supported by a number of studies on the influence...

  2. Long-term effects of serial anodal tDCS on motion perception in subjects with occipital stroke measured in the unaffected visual hemifield

    Directory of Open Access Journals (Sweden)

    Manuel C Olma

    2013-06-01

    Full Text Available Transcranial direct current stimulation (tDCS is a novel neuromodulatory tool that has seen early transition to clinical trials, although the high variability of these findings necessitates further studies in clincally-relevant populations. The majority of evidence into effects of repeated tDCS is based on research in the human motor system, but it is unclear whether the long-term effects of serial tDCS are motor-specific or transferable to other brain areas. This study aimed to examine whether serial anodal tDCS over the visual cortex can exogenously induce long-term neuroplastic changes in the visual cortex. However, when the visual cortex is affected by a cortical lesion, up-regulated endogenous neuroplastic adaptation processes may alter the susceptibility to tDCS. To this end, motion perception was investigated in the unaffected hemifield of subjects with unilateral visual cortex lesions. Twelve subjects with occipital ischaemic lesions participated in a within-subject, sham-controlled, double-blind study. MRI-registered sham or anodal tDCS (1.5 mA, 20 minutes was applied on five consecutive days over the visual cortex. Motion perception was tested before and after stimulation sessions and at 14- and 28-day follow-up. After a 16-day interval an identical study block with the other stimulation condition (anodal or sham tDCS followed. Serial anodal tDCS over the visual cortex resulted in an improvement in motion perception, a function attributed to MT/V5. This effect was still measurable at 14- and 28-day follow-up measurements. Thus, this may represent evidence for long-term tDCS-induced plasticity and has implications for the design of studies examining the time course of tDCS effects in both the visual and motor systems.

  3. Access Customized Forms

    OpenAIRE

    Cosma Emil; Jeflea Victor

    2010-01-01

    By using Word, Excel or PowerPoint one can automate routine operations using the VBA language (Visual Basic for Applications). This language is also used in Access, allowing access to data stored in tables or queries. Thus, Access and VBA resources can be used together. Access is designed for programming forms and reports (among other things), so there won’t be found any of the VBA editor’s specific forms.

  4. Influence of age, spatial memory, and ocular fixation on localization of auditory, visual, and bimodal targets by human subjects.

    Science.gov (United States)

    Dobreva, Marina S; O'Neill, William E; Paige, Gary D

    2012-12-01

    A common complaint of the elderly is difficulty identifying and localizing auditory and visual sources, particularly in competing background noise. Spatial errors in the elderly may pose challenges and even threats to self and others during everyday activities, such as localizing sounds in a crowded room or driving in traffic. In this study, we investigated the influence of aging, spatial memory, and ocular fixation on the localization of auditory, visual, and combined auditory-visual (bimodal) targets. Head-restrained young and elderly subjects localized targets in a dark, echo-attenuated room using a manual laser pointer. Localization accuracy and precision (repeatability) were quantified for both ongoing and transient (remembered) targets at response delays up to 10 s. Because eye movements bias auditory spatial perception, localization was assessed under target fixation (eyes free, pointer guided by foveal vision) and central fixation (eyes fixed straight ahead, pointer guided by peripheral vision) conditions. Spatial localization across the frontal field in young adults demonstrated (1) horizontal overshoot and vertical undershoot for ongoing auditory targets under target fixation conditions, but near-ideal horizontal localization with central fixation; (2) accurate and precise localization of ongoing visual targets guided by foveal vision under target fixation that degraded when guided by peripheral vision during central fixation; (3) overestimation in horizontal central space (±10°) of remembered auditory, visual, and bimodal targets with increasing response delay. In comparison with young adults, elderly subjects showed (1) worse precision in most paradigms, especially when localizing with peripheral vision under central fixation; (2) greatly impaired vertical localization of auditory and bimodal targets; (3) increased horizontal overshoot in the central field for remembered visual and bimodal targets across response delays; (4) greater vulnerability to

  5. Effects of Visual Communication Tool and Separable Status Display on Team Performance and Subjective Workload in Air Battle Management

    National Research Council Canada - National Science Library

    Schwartz, Daniel; Knott, Benjamin A; Galster, Scott M

    2008-01-01

    ... ambient cabin noise while performing several visual and manual tasks. The purpose of this study is to compare team performance and subjective workload on a simulated AWACS scenario, for two conditions of communication...

  6. Statistics for library and information services a primer for using open source R software for accessibility and visualization

    CERN Document Server

    Friedman, Alon

    2016-01-01

    Statistics for Library and Information Services, written for non-statisticians, provides logical, user-friendly, and step-by-step instructions to make statistics more accessible for students and professionals in the field of Information Science. It emphasizes concepts of statistical theory and data collection methodologies, but also extends to the topics of visualization creation and display, so that the reader will be able to better conduct statistical analysis and communicate his/her findings. The book is tailored for information science students and professionals. It has specific examples of dataset sets, scripts, design modules, data repositories, homework assignments, and a glossary lexicon that matches the field of Information Science. The textbook provides a visual road map that is customized specifically for Information Science instructors, students, and professionals regarding statistics and visualization. Each chapter in the book includes full-color illustrations on how to use R for the statistical ...

  7. Contrast and Strength of Visual Memory and Imagery Differentially Affect Visual Perception

    OpenAIRE

    Saad, Elyana; Silvanto, Juha

    2013-01-01

    Visual short-term memory (VSTM) and visual imagery have been shown to modulate visual perception. However, how the subjective experience of VSTM/imagery and its contrast modulate this process has not been investigated. We addressed this issue by asking participants to detect brief masked targets while they were engaged either in VSTM or visual imagery. Subjective experience of memory/imagery (strength scale), and the visual contrast of the memory/mental image (contrast scale) were assessed on...

  8. Multimedia Visualizer: An Animated, Object-Based OPAC.

    Science.gov (United States)

    Lee, Newton S.

    1991-01-01

    Describes the Multimedia Visualizer, an online public access catalog (OPAC) that uses animated visualizations to make it more user friendly. Pictures of the system are shown that illustrate the interactive objects that patrons can access, including card catalog drawers, librarian desks, and bookshelves; and access to multimedia items is described.…

  9. Der grüne Weg zu Open Access: institutionelle und fachliche Repositorien / The Green Road to Open access: institutional and subject repositories

    Directory of Open Access Journals (Sweden)

    Bauer, Bruno

    2009-06-01

    Full Text Available The recent issue 1/2009 of GMS Medizin – Bibliothek – Information has a focus on „The green road to open Access: institutional and subject repositories“. Self-archiving and storing scholarly publications on a print server were also central topics in many presentations at the 9th International Bielefeld Conference in February 2009. The authors in this issue are Birgit Schmidt and Karin Ilg-Hartecke (Open Access in Deutschland – erweiterte Perspektiven für die Wissenschaft, Christoph Bruch and Anja Lengenfelder (Unterstützung des Grünen Weges zu Open Access an der Max-Planck-Gesellschaft, Ulrich Herb and Matthias Müller (Nuancen in Grün: Betrieb eines institutionellen und disziplinären Repositoriums – Erfahrungen und Entwicklungen an der Saarländischen Universitäts- und Landesbibliothek, Timo Borst and Jan B. Weiland (EconStor: ein fachliches Repositorium für die Wirtschaftswissenschaften, Antonella de Robbio and Michael Katzmayr (The management of an international open access repository: the case of E-LIS and Christian Gumpenberger (The EPrints story: Southampton as the cradle of institutional self-archiving.Furthermore this focus issue features an interview of a representative of a research funding organisation (Repositorien: Der grüne Weg zu Open Access Publishing aus der Perspektive einer Forschungsförderungsorganisation. 10 Fragen von Bruno Bauer an Falk Reckling, Mitarbeiter des FWF Der Wissenschaftsfonds and an interview of a publisher (Repositorien: Der grüne Weg zu Open Access Publishing aus der Perspektive der International Association of Scientific, Technical & Medical Publishers (STM: 10 Fragen von Bruno Bauer an Barbara Kalumenos, Director of Public Affairs bei STM.

  10. Secondary visual workload capability with primary visual and kinesthetic-tactual displays

    Science.gov (United States)

    Gilson, R. D.; Burke, M. W.; Jagacinski, R. J.

    1978-01-01

    Subjects performed a cross-adaptive tracking task with a visual secondary display and either a visual or a quickened kinesthetic-tactual (K-T) primary display. The quickened K-T display resulted in superior secondary task performance. Comparisons of secondary workload capability with integrated and separated visual displays indicated that the superiority of the quickened K-T display was not simply due to the elimination of visual scanning. When subjects did not have to perform a secondary task, there was no significant difference between visual and quickened K-T displays in performing a critical tracking task.

  11. Subjective evaluation of two stereoscopic imaging systems exploiting visual attention to improve 3D quality of experience

    Science.gov (United States)

    Hanhart, Philippe; Ebrahimi, Touradj

    2014-03-01

    Crosstalk and vergence-accommodation rivalry negatively impact the quality of experience (QoE) provided by stereoscopic displays. However, exploiting visual attention and adapting the 3D rendering process on the fly can reduce these drawbacks. In this paper, we propose and evaluate two different approaches that exploit visual attention to improve 3D QoE on stereoscopic displays: an offline system, which uses a saliency map to predict gaze position, and an online system, which uses a remote eye tracking system to measure real time gaze positions. The gaze points were used in conjunction with the disparity map to extract the disparity of the object-of-interest. Horizontal image translation was performed to bring the fixated object on the screen plane. The user preference between standard 3D mode and the two proposed systems was evaluated through a subjective evaluation. Results show that exploiting visual attention significantly improves image quality and visual comfort, with a slight advantage for real time gaze determination. Depth quality is also improved, but the difference is not significant.

  12. Research on the Design of Visually Impaired Interactive Accessibility in Large Urban Public Transport System

    Science.gov (United States)

    Zhang, Weiru

    2017-12-01

    In medieval times, due to people’s reliance on belief, public space of Christianity came into being. With the rise of secularization, religion gradually turned into private belief, and accordingly public space returned to private space. In the 21st century, due to people’s reliance on intelligent devices, information-interactive public space emerges, and as information interaction is constantly constraining the visually impaired, public space regressed to the exclusive space of limited people[1]. Modernity is marked by technical rationality, but an ensuing basic problem lies in the separation between human action, ethics and public space. When technology fails to overcome obstacles for a particular group, the gap between the burgeoning intelligent phenomena and the increasing ratio of visually impaired is also expanding, ultimately resulting in a growing number of “blind spots” in information-interactive space. Technological innovation not only promotes the development of the information industry, but also promotes the rapid development of the transportation industry. Traffic patterns are diversifying and diverging nowadays, but it’s a fatal blow for people with visually disabilities, Because they still can only experience the most traditional mode of transportation, sometimes even not go out. How to guarantee their interactive accessibility in large urban public transport system right, currently, is a very important research direction.

  13. Stream specificity and asymmetries in feature binding and content-addressable access in visual encoding and memory.

    Science.gov (United States)

    Huynh, Duong L; Tripathy, Srimant P; Bedell, Harold E; Ögmen, Haluk

    2015-01-01

    Human memory is content addressable-i.e., contents of the memory can be accessed using partial information about the bound features of a stored item. In this study, we used a cross-feature cuing technique to examine how the human visual system encodes, binds, and retains information about multiple stimulus features within a set of moving objects. We sought to characterize the roles of three different features (position, color, and direction of motion, the latter two of which are processed preferentially within the ventral and dorsal visual streams, respectively) in the construction and maintenance of object representations. We investigated the extent to which these features are bound together across the following processing stages: during stimulus encoding, sensory (iconic) memory, and visual short-term memory. Whereas all features examined here can serve as cues for addressing content, their effectiveness shows asymmetries and varies according to cue-report pairings and the stage of information processing and storage. Position-based indexing theories predict that position should be more effective as a cue compared to other features. While we found a privileged role for position as a cue at the stimulus-encoding stage, position was not the privileged cue at the sensory and visual short-term memory stages. Instead, the pattern that emerged from our findings is one that mirrors the parallel processing streams in the visual system. This stream-specific binding and cuing effectiveness manifests itself in all three stages of information processing examined here. Finally, we find that the Leaky Flask model proposed in our previous study is applicable to all three features.

  14. Metacognition of visual short-term memory: Dissociation between objective and subjective components of VSTM

    Directory of Open Access Journals (Sweden)

    Silvia eBona

    2013-02-01

    Full Text Available The relationship between the objective accuracy of visual-short term memory (VSTM representations and their subjective conscious experience is unknown. We investigated this issue by assessing how the objective and subjective components of VSTM in a delayed cue-target orientation discrimination task are affected by intervening distracters. On each trial, participants were shown a memory cue (a grating, the orientation of which they were asked to hold in memory. On approximately half of the trials, a distractor grating appeared during the maintenance interval; its orientation was either identical to that of the memory cue, or it differed by 10 or 40 degrees. The distractors were masked and presented briefly, so they were only consciously perceived on a subset of trials. At the end of the delay period, a memory test probe was presented, and participants were asked to indicate whether it was tilted to the left or right relative to the memory cue (VSTM accuracy; objective performance. In order to assess subjective metacognition, participants were asked indicate the vividness of their memory for the original memory cue. Finally, participants were asked rate their awareness of the distracter. Results showed that objective VSTM performance was impaired by distractors only when the distractors were very different from the cue, and that this occurred with both subjectively visible and invisible distractors. Subjective metacognition, however, was impaired by distractors of all orientations, but only when these distractors were subjectively invisible. Our results thus indicate that the objective and subjective components of VSTM are to some extent dissociable.

  15. Inter- and intra-observer agreement of BI-RADS-based subjective visual estimation of amount of fibroglandular breast tissue with magnetic resonance imaging: comparison to automated quantitative assessment

    International Nuclear Information System (INIS)

    Wengert, G.J.; Helbich, T.H.; Woitek, R.; Kapetas, P.; Clauser, P.; Baltzer, P.A.; Vogl, W.D.; Weber, M.; Meyer-Baese, A.; Pinker, Katja

    2016-01-01

    To evaluate the inter-/intra-observer agreement of BI-RADS-based subjective visual estimation of the amount of fibroglandular tissue (FGT) with magnetic resonance imaging (MRI), and to investigate whether FGT assessment benefits from an automated, observer-independent, quantitative MRI measurement by comparing both approaches. Eighty women with no imaging abnormalities (BI-RADS 1 and 2) were included in this institutional review board (IRB)-approved prospective study. All women underwent un-enhanced breast MRI. Four radiologists independently assessed FGT with MRI by subjective visual estimation according to BI-RADS. Automated observer-independent quantitative measurement of FGT with MRI was performed using a previously described measurement system. Inter-/intra-observer agreements of qualitative and quantitative FGT measurements were assessed using Cohen's kappa (k). Inexperienced readers achieved moderate inter-/intra-observer agreement and experienced readers a substantial inter- and perfect intra-observer agreement for subjective visual estimation of FGT. Practice and experience reduced observer-dependency. Automated observer-independent quantitative measurement of FGT was successfully performed and revealed only fair to moderate agreement (k = 0.209-0.497) with subjective visual estimations of FGT. Subjective visual estimation of FGT with MRI shows moderate intra-/inter-observer agreement, which can be improved by practice and experience. Automated observer-independent quantitative measurements of FGT are necessary to allow a standardized risk evaluation. (orig.)

  16. Inter- and intra-observer agreement of BI-RADS-based subjective visual estimation of amount of fibroglandular breast tissue with magnetic resonance imaging: comparison to automated quantitative assessment

    Energy Technology Data Exchange (ETDEWEB)

    Wengert, G.J.; Helbich, T.H.; Woitek, R.; Kapetas, P.; Clauser, P.; Baltzer, P.A. [Medical University of Vienna/ Vienna General Hospital, Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Vienna (Austria); Vogl, W.D. [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Computational Imaging Research Lab, Wien (Austria); Weber, M. [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Division of General and Pediatric Radiology, Wien (Austria); Meyer-Baese, A. [State University of Florida, Department of Scientific Computing in Medicine, Tallahassee, FL (United States); Pinker, Katja [Medical University of Vienna/ Vienna General Hospital, Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Vienna (Austria); State University of Florida, Department of Scientific Computing in Medicine, Tallahassee, FL (United States); Memorial Sloan-Kettering Cancer Center, Department of Radiology, Molecular Imaging and Therapy Services, New York City, NY (United States)

    2016-11-15

    To evaluate the inter-/intra-observer agreement of BI-RADS-based subjective visual estimation of the amount of fibroglandular tissue (FGT) with magnetic resonance imaging (MRI), and to investigate whether FGT assessment benefits from an automated, observer-independent, quantitative MRI measurement by comparing both approaches. Eighty women with no imaging abnormalities (BI-RADS 1 and 2) were included in this institutional review board (IRB)-approved prospective study. All women underwent un-enhanced breast MRI. Four radiologists independently assessed FGT with MRI by subjective visual estimation according to BI-RADS. Automated observer-independent quantitative measurement of FGT with MRI was performed using a previously described measurement system. Inter-/intra-observer agreements of qualitative and quantitative FGT measurements were assessed using Cohen's kappa (k). Inexperienced readers achieved moderate inter-/intra-observer agreement and experienced readers a substantial inter- and perfect intra-observer agreement for subjective visual estimation of FGT. Practice and experience reduced observer-dependency. Automated observer-independent quantitative measurement of FGT was successfully performed and revealed only fair to moderate agreement (k = 0.209-0.497) with subjective visual estimations of FGT. Subjective visual estimation of FGT with MRI shows moderate intra-/inter-observer agreement, which can be improved by practice and experience. Automated observer-independent quantitative measurements of FGT are necessary to allow a standardized risk evaluation. (orig.)

  17. [As opposed to normal subjects, eyelid position doesn't interfere with postural behavior in blind subjects].

    Science.gov (United States)

    Olin, C; Rougier, P

    2009-12-01

    A previous study has shown some behavioral differences in normal subjects depending on the position of the eyelids: the postural behavior was varying if the subject had the eyes open in darkness or the eyes closed. In this study, we explore the possible role of vision on this behavior. The postural behavior of 12 blind and nine visually impaired participants was studied during undisturbed upright stance. In this sample, no difference was found in the conditions eyes open in the dark and eyes closed: the observed behavior in blind and visually impaired subjects is different compared to normal sighted subjects who show a visual preference even in total darkness when the eyes are open. Our two groups (blind and visually impaired) actually show a difference on the median frequency of the centre of gravity displacements. Our results suggest an adaptive mechanism of the central nervous system in healthy individuals to predominantly weigh visual cues when the eyelids remain open. Good visual acuity and time seem to be necessary for this process.

  18. Cortical networks involved in visual awareness independent of visual attention

    OpenAIRE

    Webb, Taylor W.; Igelström, Kajsa M.; Schurger, Aaron; Graziano, Michael S. A.

    2016-01-01

    Do specific areas of the brain participate in subjective visual experience? We measured brain activity in humans using fMRI. Participants were aware of a visual stimulus in one condition and unaware of it in another condition. The two conditions were balanced for their effect on visual attention. Specific brain areas were more active in the aware than in the unaware condition, suggesting they were involved in subjective awareness independent of attention. The largest cluster of activity was f...

  19. Do We Know others' Visual Liking?

    Directory of Open Access Journals (Sweden)

    Ryosuke Niimi

    2014-12-01

    Full Text Available Although personal liking varies considerably, there is a general trend of liking shared by many people (public favour. Visual liking in particular may be largely shared by people, as it is strongly influenced by relatively low-level perceptual factors. If so, it is likely that people have correct knowledge of public favour. We examined the human ability to predict public favour. In three experiments, participants rated the subjective likability of various visual objects (e.g. car, chair, and predicted the mean liking rating by other participants. Irrespective of the object's category, the correlation between individual prediction and actual mean liking of others (prediction validity was not higher than the correlation between the predictor's own liking and the mean liking of others. Further, individual prediction correlated more with the predictor's own liking than it was with others' liking. Namely, predictions were biased towards the predictor's subjective liking (a variation of the false consensus effect. The results suggest that humans do not have (or cannot access correct knowledge of public favour. It was suggested that increasing the number of predictors is the appropriate strategy for making a good prediction of public favour.

  20. Left Gastric Vein Visualization with Hepatopetal Flow Information in Healthy Subjects Using Non-Contrast-Enhanced Magnetic Resonance Angiography with Balanced Steady-State Free-Precession Sequence and Time-Spatial Labeling Inversion Pulse.

    Science.gov (United States)

    Furuta, Akihiro; Isoda, Hiroyoshi; Ohno, Tsuyoshi; Ono, Ayako; Yamashita, Rikiya; Arizono, Shigeki; Kido, Aki; Sakashita, Naotaka; Togashi, Kaori

    2018-01-01

    To selectively visualize the left gastric vein (LGV) with hepatopetal flow information by non-contrast-enhanced magnetic resonance angiography under a hypothesis that change in the LGV flow direction can predict the development of esophageal varices; and to optimize the acquisition protocol in healthy subjects. Respiratory-gated three-dimensional balanced steady-state free-precession scans were conducted on 31 healthy subjects using two methods (A and B) for visualizing the LGV with hepatopetal flow. In method A, two time-spatial labeling inversion pulses (Time-SLIP) were placed on the whole abdomen and the area from the gastric fornix to the upper body, excluding the LGV area. In method B, nonselective inversion recovery pulse was used and one Time-SLIP was placed on the esophagogastric junction. The detectability and consistency of LGV were evaluated using the two methods and ultrasonography (US). Left gastric veins by method A, B, and US were detected in 30 (97%), 24 (77%), and 23 (74%) subjects, respectively. LGV flow by US was hepatopetal in 22 subjects and stagnant in one subject. All hepatopetal LGVs by US coincided with the visualized vessels in both methods. One subject with non-visualized LGV in method A showed stagnant LGV by US. Hepatopetal LGV could be selectively visualized by method A in healthy subjects.

  1. Brain-heart linear and nonlinear dynamics during visual emotional elicitation in healthy subjects.

    Science.gov (United States)

    Valenza, G; Greco, A; Gentili, C; Lanata, A; Toschi, N; Barbieri, R; Sebastiani, L; Menicucci, D; Gemignani, A; Scilingo, E P

    2016-08-01

    This study investigates brain-heart dynamics during visual emotional elicitation in healthy subjects through linear and nonlinear coupling measures of EEG spectrogram and instantaneous heart rate estimates. To this extent, affective pictures including different combinations of arousal and valence levels, gathered from the International Affective Picture System, were administered to twenty-two healthy subjects. Time-varying maps of cortical activation were obtained through EEG spectral analysis, whereas the associated instantaneous heartbeat dynamics was estimated using inhomogeneous point-process linear models. Brain-Heart linear and nonlinear coupling was estimated through the Maximal Information Coefficient (MIC), considering EEG time-varying spectra and point-process estimates defined in the time and frequency domains. As a proof of concept, we here show preliminary results considering EEG oscillations in the θ band (4-8 Hz). This band, indeed, is known in the literature to be involved in emotional processes. MIC highlighted significant arousal-dependent changes, mediated by the prefrontal cortex interplay especially occurring at intermediate arousing levels. Furthermore, lower and higher arousing elicitations were associated to not significant brain-heart coupling changes in response to pleasant/unpleasant elicitations.

  2. Subjective and objective measurements of visual fatigue induced by excessive disparities in stereoscopic images

    Science.gov (United States)

    Jung, Yong Ju; Kim, Dongchan; Sohn, Hosik; Lee, Seong-il; Park, Hyun Wook; Ro, Yong Man

    2013-03-01

    As stereoscopic displays have spread, it is important to know what really causes the visual fatigue and discomfort and what happens in the visual system in the brain behind the retina while viewing stereoscopic 3D images on the displays. In this study, functional magnetic resonance imaging (fMRI) was used for the objective measurement to assess the human brain regions involved in the processing of the stereoscopic stimuli with excessive disparities. Based on the subjective measurement results, we selected two subsets of comfort videos and discomfort videos in our dataset. Then, a fMRI experiment was conducted with the subsets of comfort and discomfort videos in order to identify which brain regions activated while viewing the discomfort videos in a stereoscopic display. We found that, when viewing a stereoscopic display, the right middle frontal gyrus, the right inferior frontal gyrus, the right intraparietal lobule, the right middle temporal gyrus, and the bilateral cuneus were significantly activated during the processing of excessive disparities, compared to those of small disparities (< 1 degree).

  3. Novel Scientific Visualization Interfaces for Interactive Information Visualization and Sharing

    Science.gov (United States)

    Demir, I.; Krajewski, W. F.

    2012-12-01

    As geoscientists are confronted with increasingly massive datasets from environmental observations to simulations, one of the biggest challenges is having the right tools to gain scientific insight from the data and communicate the understanding to stakeholders. Recent developments in web technologies make it easy to manage, visualize and share large data sets with general public. Novel visualization techniques and dynamic user interfaces allow users to interact with data, and modify the parameters to create custom views of the data to gain insight from simulations and environmental observations. This requires developing new data models and intelligent knowledge discovery techniques to explore and extract information from complex computational simulations or large data repositories. Scientific visualization will be an increasingly important component to build comprehensive environmental information platforms. This presentation provides an overview of the trends and challenges in the field of scientific visualization, and demonstrates information visualization and communication tools in the Iowa Flood Information System (IFIS), developed within the light of these challenges. The IFIS is a web-based platform developed by the Iowa Flood Center (IFC) to provide access to and visualization of flood inundation maps, real-time flood conditions, flood forecasts both short-term and seasonal, and other flood-related data for communities in Iowa. The key element of the system's architecture is the notion of community. Locations of the communities, those near streams and rivers, define basin boundaries. The IFIS provides community-centric watershed and river characteristics, weather (rainfall) conditions, and streamflow data and visualization tools. Interactive interfaces allow access to inundation maps for different stage and return period values, and flooding scenarios with contributions from multiple rivers. Real-time and historical data of water levels, gauge heights, and

  4. Using Visual Information to Determine the Subjective Valuation of Public Space for Transportation : Application to Subway Crowding Costs in NYC

    Science.gov (United States)

    2017-11-30

    The objective of this project is to explore the role of visual information in determining the users subjective valuation of multidimensional trip attributes that are relevant in decision-making, but are neglected in standard travel demand models. ...

  5. Understanding visual consciousness in autism spectrum disorders.

    Science.gov (United States)

    Yatziv, Tal; Jacobson, Hilla

    2015-01-01

    The paper focuses on the question of what the (visual) perceptual differences are between individuals with autism spectrum disorders (ASD) and typically developing (TD) individuals. We argue against the view that autistic subjects have a deficiency in the most basic form of perceptual consciousness-namely, phenomenal consciousness. Instead, we maintain, the perceptual atypicality of individuals with autism is of a more conceptual and cognitive sort-their perceptual experiences share crucial aspects with TD individuals. Our starting point is Ben Shalom's (2005, 2009) three-level processing framework for explaining atypicality in several domains of processing among autistics, which we compare with two other tripartite models of perception-Jackendoff's (1987) and Prinz's (2000, 2005a, 2007) Intermediate Level Hypothesis and Lamme's (2004, 2006, 2010) neural account of consciousness. According to these models, whereas the second level of processing is concerned with viewer-centered visual representations of basic visual properties and incorporates some early forms of integration, the third level is more cognitive and conceptual. We argue that the data suggest that the atypicality in autism is restricted mainly to the third level. More specifically, second-level integration, which is the mark of phenomenal consciousness, is typical, yet third-level integration of perceptual objects and concepts is atypical. Thus, the basic experiences of individuals with autism are likely to be similar to typical subjects' experiences; the main difference lies in the sort of cognitive access the subjects have to their experiences. We conclude by discussing implications of the suggested analysis of experience in autism for conceptions of phenomenal consciousness.

  6. Visualization in cryogenic environment: Application to two-phase studies

    Science.gov (United States)

    Rousset, Bernard; Chatain, Denis; Puech, Laurent; Thibault, Pierre; Viargues, François; Wolf, Pierre-Etienne

    2009-10-01

    This paper reviews recent technical developments devoted to the study of cryogenic two-phase fluids. These techniques span from simple flow visualization to quantitative measurements of light scattering. It is shown that simple flow pattern configurations are obtained using classical optical tools (CCD cameras, endoscopes), even in most severe environments (high vacuum, high magnetic field). Quantitative measurements include laser velocimetry, particle sizing, and light scattering analysis. In the case of magnetically compensated gravity boiling oxygen, optical access is used to control the poistioning of a bubble subject to buoyancy forces in an experimental cell. Flow visualization on a two-phase superfluid helium pipe-flow, performed as a support of LHC cooldown studies, leads to flow pattern characterization. Visualization includes stratified and atomized flows. Thanks to the low refractive index contrast between the liquid and its vapor, quantitative results on droplet densities can be obtained even in a multiple scattering regime.

  7. A University Web Portal redesign applying accessibility patterns. Breaking Down Barriers for Visually Impaired Users

    Directory of Open Access Journals (Sweden)

    Hernán Sosa

    2015-08-01

    Full Text Available Definitely, the WWW and ICTs have become the preferred media for the interaction between society and its citizens, and public and private organizations have today the possibility of deploying their activities through the Web. In particular, university education is a domain where the benefits of these technological resources can strongly contribute in caring for students. However, most university Web portals are inaccessible to their user community (students, professors, and non-teaching staff, between others, since these portals do not take into account the needs of people with different capabilities. In this work, we propose an accessibility pattern driven process to the redesign of university Web portals, aiming to break down barriers for visually impaired users. The approach is implemented to a real case study: the Web portal of Universidad Nacional de la Patagonia Austral (UNPA. The results come from applying accessibility recommendations and evaluation tools (automatic and manual from internationally recognized organizations, to both versions of the Web portal: the original and the redesign one.

  8. Neural circuits of eye movements during performance of the visual exploration task, which is similar to the responsive search score task, in schizophrenia patients and normal subjects

    International Nuclear Information System (INIS)

    Nemoto, Yasundo; Matsuda, Tetsuya; Matsuura, Masato

    2004-01-01

    Abnormal exploratory eye movements have been studied as a biological marker for schizophrenia. Using functional MRI (fMRI), we investigated brain activations of 12 healthy and 8 schizophrenic subjects during performance of a visual exploration task that is similar to the responsive search score task to clarify the neural basis of the abnormal exploratory eye movement. Performance data, such as the number of eye movements, the reaction time, and the percentage of correct answers showed no significant differences between the two groups. Only the normal subjects showed activations at the bilateral thalamus and the left anterior medial frontal cortex during the visual exploration tasks. In contrast, only the schizophrenic subjects showed activations at the right anterior cingulate gyms during the same tasks. The activation at the different locations between the two groups, the left anterior medial frontal cortex in normal subjects and the right anterior cingulate gyrus in schizophrenia subjects, was explained by the feature of the visual tasks. Hypoactivation at the bilateral thalamus supports a dysfunctional filtering theory of schizophrenia. (author)

  9. Evidence-Based Communication Practices for Children with Visual Impairments and Additional Disabilities: An Examination of Single-Subject Design Studies

    Science.gov (United States)

    Parker, Amy T.; Grimmett, Eric S.; Summers, Sharon

    2008-01-01

    This review examines practices for building effective communication strategies for children with visual impairments, including those with additional disabilities, that have been tested by single-subject design methodology. The authors found 30 studies that met the search criteria and grouped intervention strategies to align any evidence of the…

  10. Pro Access 2010 Development

    CERN Document Server

    Collins, Mark

    2011-01-01

    Pro Access 2010 Development is a fundamental resource for developing business applications that take advantage of the features of Access 2010 and the many sources of data available to your business. In this book, you'll learn how to build database applications, create Web-based databases, develop macros and Visual Basic for Applications (VBA) tools for Access applications, integrate Access with SharePoint and other business systems, and much more. Using a practical, hands-on approach, this book will take you through all the facets of developing Access-based solutions, such as data modeling, co

  11. Examination of accessibility for disabled people at metro stations

    Directory of Open Access Journals (Sweden)

    Evren Burak Enginöz

    2016-07-01

    enforcements, as well as insufficient user’s knowledge cause our cities inaccessible. Therefore, we have to increase the awareness of our community on accessible city life and transportation systems rather than make laws and hope for recovery. In this context, a case study is intended to examine the approaches on barrier-free design and level of accessibility at metro stations in Turkey. With the scope of this case study, current informative, stimulating and guiding regulations, vertical and horizontal implementations on circulation areas at metro stations are examined by an accessible design control list Accessible design control list consists of 28 questions that have been selected from Turkish Ministry of Family and Social Policies-People with Disabilities and Elderly General Service Accessibility check Lists and Turkish World Handicapped Foundation- Outdoors and Indoors Accessibility Check Lists. With the help of question we can examine the passengers’ expectations on the quality of informative, stimulating and guiding signboards at entrance, circulations and surroundings of metro stations; except the legislations related to the product sizes and constraints that designers or professionals have to obey The questions are answered by disabled passengers who use Kadıkoy Ayrılık Cesme main transmission metro station. Disabled passengers are divided into two subject groups. First subject group consist of 5 visually impaired and partially impaired people. The second subject group consist of 7 wheelchair users. Experimentally, asked all the subject groups to make a journey beginning from the entrance of metro station to the train platforms without getting any help. After they completed their journey, they were requested to answer the questions of control list and describe the positive and negative situations from their experiences. According to the result of examining the approaches on barrier-free design and the level of accessibility at Ayrılıkcesme main transmission

  12. O emprego de linguagens acessíveis para alunos com deficiência visual em aulas de Óptica Using accessible language with students with visual impairment when studying Optics

    Directory of Open Access Journals (Sweden)

    Eder Pires de Camargo

    2008-12-01

    Full Text Available O presente artigo encontra-se inserido dentro de um estudo que busca compreender as principais alternativas para a inclusão de alunos com deficiência visual no contexto do ensino de física. Focalizando aulas de óptica, analisa as viabilidades comunicacionais entre licenciandos e discentes com deficiência visual. Para tal, enfatiza as estruturas empírica e semântico-sensorial das linguagens utilizadas, indicando fatores geradores de acessibilidade às informações veiculadas. Recomenda, ainda, alternativas que visam dar condições à participação efetiva do discente com deficiência visual no processo comunicativo, das quais se destacam: a identificação da estrutura semântico-sensorial dos significados veiculados, o conhecimento da história visual do aluno, a utilização de linguagens de estrutura empírica tátil-auditiva interdependente em contextos interativos, bem como, a exploração das potencialidades comunicacionais das linguagens constituídas de estruturas empíricas fundamental auditiva, e auditiva e visual independentes.This paper is part of a broader study aiming to understand the main alternatives for including students with visual impairments in the context of teaching physics. It analyzes the feasibility of communication between future physics teachers and their students with visual impairments during classes on optics. To this end, the study emphasizes empirical and semantic-sensorial structures of language that need to be used, indicating factors that enable access to information the teacher means to impart. Alternatives are recommended in order to enable students with visual impairments to participate as fully as possible in the communicative process. Among them we emphasize: the identification of semantic-sensorial structures; understanding the student's visual history; using interdependent empirical tactile-audio language structures in interactive contexts, as well as exploring communicational potentialities

  13. Clinical study on relationship of visualization of the cerebral arteries in MR angiography to age, sex, laterality or lacunar infarction in neurologically normal subjects

    Energy Technology Data Exchange (ETDEWEB)

    Kajiya, Yoriko [Kagoshima Univ. (Japan). Faculty of Medicine

    1995-08-01

    The purpose of this study is to assess the correlation between the visualization of cerebral peripheral arteries in magnetic resonance angiography (MRA) and aging, sex, laterality or lacunar infarctions in magnetic resonance imaging (MRI). Two hundred forty-four neurologically normal subjects (119 males and 125 females, aged 7 to 82 yrs.) were evaluated with MRA and MRI. A three-dimensional Fourier transformation (3DFT-TOF) pulse sequence with slab thickness of 115 mm was used to obtain axial, sagittal and coronal projection images. The imaging parameters were 30/11/1 (TR/TE/excitations) using a 20 degree flip angle and the voxel size was 0.9 x 1.1 x 0.9 mm. A total of 6 arteries including bilateral anterior cerebral arteries (ACAs), middle cerebral arteries (MCAs) and posterior cerebral arteries (PCAs) for every subject were each graded into 8 scores by the degree of visualization of the arteries. Asymptomatic lacunar infarctions were analyzed in subjects of fifties or more. They were scored as 0-2 based on their size and the scores were summed. An age-related decline of visualization of the cerebral arteries was observed in ACA (r=-0.603, p<0.001), MCA (r=-0.452, p<0.001) and PCA (r=-0.537, p<0.001). Females during the fifth decade had a higher score of visualization of the arteries than males (p<0.01). No substantial relationship was observed between visualization of the arteries and sex in other decades, laterality or lacunar infarctions. The MRA using a 3DFT-TOF pulse sequence with slab thickness of 115 mm disclosed an age-related decline of visualization of the cerebral arteries and a sex-dependent difference of the visualization in the fifth decade probably due to the decline of the blood flow velocity with aging and a difference in it between females and males in the fifth decade, respectively. (J.P.N.).

  14. Clinical study on relationship of visualization of the cerebral arteries in MR angiography to age, sex, laterality or lacunar infarction in neurologically normal subjects

    International Nuclear Information System (INIS)

    Kajiya, Yoriko

    1995-01-01

    The purpose of this study is to assess the correlation between the visualization of cerebral peripheral arteries in magnetic resonance angiography (MRA) and aging, sex, laterality or lacunar infarctions in magnetic resonance imaging (MRI). Two hundred forty-four neurologically normal subjects (119 males and 125 females, aged 7 to 82 yrs.) were evaluated with MRA and MRI. A three-dimensional Fourier transformation (3DFT-TOF) pulse sequence with slab thickness of 115 mm was used to obtain axial, sagittal and coronal projection images. The imaging parameters were 30/11/1 (TR/TE/excitations) using a 20 degree flip angle and the voxel size was 0.9 x 1.1 x 0.9 mm. A total of 6 arteries including bilateral anterior cerebral arteries (ACAs), middle cerebral arteries (MCAs) and posterior cerebral arteries (PCAs) for every subject were each graded into 8 scores by the degree of visualization of the arteries. Asymptomatic lacunar infarctions were analyzed in subjects of fifties or more. They were scored as 0-2 based on their size and the scores were summed. An age-related decline of visualization of the cerebral arteries was observed in ACA (r=-0.603, p<0.001), MCA (r=-0.452, p<0.001) and PCA (r=-0.537, p<0.001). Females during the fifth decade had a higher score of visualization of the arteries than males (p<0.01). No substantial relationship was observed between visualization of the arteries and sex in other decades, laterality or lacunar infarctions. The MRA using a 3DFT-TOF pulse sequence with slab thickness of 115 mm disclosed an age-related decline of visualization of the cerebral arteries and a sex-dependent difference of the visualization in the fifth decade probably due to the decline of the blood flow velocity with aging and a difference in it between females and males in the fifth decade, respectively. (J.P.N.)

  15. Constructing visual representations

    DEFF Research Database (Denmark)

    Huron, Samuel; Jansen, Yvonne; Carpendale, Sheelagh

    2014-01-01

    tangible building blocks. We learned that all participants, most of whom had little experience in visualization authoring, were readily able to create and talk about their own visualizations. Based on our observations, we discuss participants’ actions during the development of their visual representations......The accessibility of infovis authoring tools to a wide audience has been identified as a major research challenge. A key task in the authoring process is the development of visual mappings. While the infovis community has long been deeply interested in finding effective visual mappings......, comparatively little attention has been placed on how people construct visual mappings. In this paper, we present the results of a study designed to shed light on how people transform data into visual representations. We asked people to create, update and explain their own information visualizations using only...

  16. Perceptual integration without conscious access

    NARCIS (Netherlands)

    Fahrenfort, Johannes J.; Van Leeuwen, Jonathan; Olivers, Christian N.L.; Hogendoorn, Hinze

    2017-01-01

    The visual system has the remarkable ability to integrate fragmentary visual input into a perceptually organized collection of surfaces and objects, a process we refer to as perceptual integration. Despite a long tradition of perception research, it is not known whether access to consciousness is

  17. Toward an improved haptic zooming algorithm for graphical information accessed by individuals who are blind and visually impaired.

    Science.gov (United States)

    Rastogi, Ravi; Pawluk, Dianne T V

    2013-01-01

    An increasing amount of information content used in school, work, and everyday living is presented in graphical form. Unfortunately, it is difficult for people who are blind or visually impaired to access this information, especially when many diagrams are needed. One problem is that details, even in relatively simple visual diagrams, can be very difficult to perceive using touch. With manually created tactile diagrams, these details are often presented in separate diagrams which must be selected from among others. Being able to actively zoom in on an area of a single diagram so that the details can be presented at a reasonable size for exploration purposes seems a simpler approach for the user. However, directly using visual zooming methods have some limitations when used haptically. Therefore, a new zooming method is proposed to avoid these pitfalls. A preliminary experiment was performed to examine the usefulness of the algorithm compared to not using zooming. The results showed that the number of correct responses improved with the developed zooming algorithm and participants found it to be more usable than not using zooming for exploration of a floor map.

  18. Vision as subjective perception; La vision, une perception subjective

    Energy Technology Data Exchange (ETDEWEB)

    Reppas, J.B. [Harvard Univ., Cambridge, MA (United States). Biological Labs.; Dale, A.; Sereno, M.; Tootell, R.

    1996-07-01

    The human brain is not very different of the monkey`s one: at least, its visual cortex is organized as a similar scheme. Specialized areas in the movement analysis are found and others in the forms perception. In this work, the author tries to answer to the following questions: (1)why so many visual areas? What are exactly their role in vision? Thirteen years of experimentation have not allowed to answer to these questions. The cerebral NMR imaging gives the opportunity of understanding the subjective perception of the visual world. One step which is particularly described in this work is to know how the visual cortex reacts to the optical illusions. (O.M.).

  19. Perceptual integration without conscious access.

    Science.gov (United States)

    Fahrenfort, Johannes J; van Leeuwen, Jonathan; Olivers, Christian N L; Hogendoorn, Hinze

    2017-04-04

    The visual system has the remarkable ability to integrate fragmentary visual input into a perceptually organized collection of surfaces and objects, a process we refer to as perceptual integration. Despite a long tradition of perception research, it is not known whether access to consciousness is required to complete perceptual integration. To investigate this question, we manipulated access to consciousness using the attentional blink. We show that, behaviorally, the attentional blink impairs conscious decisions about the presence of integrated surface structure from fragmented input. However, despite conscious access being impaired, the ability to decode the presence of integrated percepts remains intact, as shown through multivariate classification analyses of electroencephalogram (EEG) data. In contrast, when disrupting perception through masking, decisions about integrated percepts and decoding of integrated percepts are impaired in tandem, while leaving feedforward representations intact. Together, these data show that access consciousness and perceptual integration can be dissociated.

  20. Public Interest in Accessing the INIS Collection

    International Nuclear Information System (INIS)

    Savić, Dobrica

    2016-01-01

    Since its creation in 1970, the International Nuclear Information System (INIS) has collected and provided access to more than 3.8 million bibliographic references to publications, documents, technical reports, non‐copyrighted documentation, and other grey literature, as well as over a million full texts. Overall, there are 800 GB of data in the INIS repository. Public interest in accessing this collection has been remarkable. This year alone, there were more than one million sessions and almost two million page views. During the same period, there were 1.6 million full text document downloads. The INIS collection consists of seven types of literature – computer media, patents, books, reports, journal articles, miscellaneous and audio‐visuals. This paper provides an overview of the INIS collection subject coverage, and the distribution of different types of grey literature. It also provides INIS repository access statistics based on Google Analytics and other Web search data pertaining to public interest in accessing these different types of literature and the uniqueness of the collection. As one of the world's largest collections of published information on the peaceful uses of nuclear science and technology, INIS represents an extraordinary example of world cooperation. 154 INIS members share and allow access to their valuable nuclear information resources, preserving them for future generations and offering a freely available nuclear knowledge repository. (author)

  1. Accessible Geoscience - Digital Fieldwork

    Science.gov (United States)

    Meara, Rhian

    2017-04-01

    Accessible Geoscience is a developing field of pedagogic research aimed at widening participation in Geography, Earth and Environmental Science (GEES) subjects. These subjects are often less commonly associated with disabilities, ethnic minorities, low income socio-economic groups and females. While advancements and improvements have been made in the inclusivity of these subject areas in recent years, access and participation of disabled students remains low. While universities are legally obligated to provide reasonable adjustments to ensure accessibility, the assumed incompatibility of GEES subjects and disability often deters students from applying to study these courses at a university level. Instead of making reasonable adjustments if and when they are needed, universities should be aiming to develop teaching materials, spaces and opportunities which are accessible to all, which in turn will allow all groups to participate in the GEES subjects. With this in mind, the Swansea Geography Department wish to enhance the accessibility of our undergraduate degree by developing digital field work opportunities. In the first instance, we intend to digitise three afternoon excursions which are run as part of a 1st year undergraduate module. Each of the field trips will be digitized into English- and Welsh-medium formats. In addition, each field trip will be digitized into British Sign Language (BSL) to allow for accessibility for D/deaf and hard of hearing students. Subtitles will also be made available in each version. While the main focus of this work is to provide accessible fieldwork opportunities for students with disabilities, this work also has additional benefits. Students within the Geography Department will be able to revisit the field trips, to revise and complete associated coursework. The use of digitized field work should not replace opportunities for real field work, but its use by the full cohort of students will begin to "normalize" accessible field

  2. A link between visual disambiguation and visual memory.

    Science.gov (United States)

    Hegdé, Jay; Kersten, Daniel

    2010-11-10

    Sensory information in the retinal image is typically too ambiguous to support visual object recognition by itself. Theories of visual disambiguation posit that to disambiguate, and thus interpret, the incoming images, the visual system must integrate the sensory information with previous knowledge of the visual world. However, the underlying neural mechanisms remain unclear. Using functional magnetic resonance imaging (fMRI) of human subjects, we have found evidence for functional specialization for storing disambiguating information in memory versus interpreting incoming ambiguous images. Subjects viewed two-tone, "Mooney" images, which are typically ambiguous when seen for the first time but are quickly disambiguated after viewing the corresponding unambiguous color images. Activity in one set of regions, including a region in the medial parietal cortex previously reported to play a key role in Mooney image disambiguation, closely reflected memory for previously seen color images but not the subsequent disambiguation of Mooney images. A second set of regions, including the superior temporal sulcus, showed the opposite pattern, in that their responses closely reflected the subjects' percepts of the disambiguated Mooney images on a stimulus-to-stimulus basis but not the memory of the corresponding color images. Functional connectivity between the two sets of regions was stronger during those trials in which the disambiguated percept was stronger. This functional interaction between brain regions that specialize in storing disambiguating information in memory versus interpreting incoming ambiguous images may represent a general mechanism by which previous knowledge disambiguates visual sensory information.

  3. Geoscience data visualization and analysis using GeoMapApp

    Science.gov (United States)

    Ferrini, Vicki; Carbotte, Suzanne; Ryan, William; Chan, Samantha

    2013-04-01

    Increased availability of geoscience data resources has resulted in new opportunities for developing visualization and analysis tools that not only promote data integration and synthesis, but also facilitate quantitative cross-disciplinary access to data. Interdisciplinary investigations, in particular, frequently require visualizations and quantitative access to specialized data resources across disciplines, which has historically required specialist knowledge of data formats and software tools. GeoMapApp (www.geomapapp.org) is a free online data visualization and analysis tool that provides direct quantitative access to a wide variety of geoscience data for a broad international interdisciplinary user community. While GeoMapApp provides access to online data resources, it can also be packaged to work offline through the deployment of a small portable hard drive. This mode of operation can be particularly useful during field programs to provide functionality and direct access to data when a network connection is not possible. Hundreds of data sets from a variety of repositories are directly accessible in GeoMapApp, without the need for the user to understand the specifics of file formats or data reduction procedures. Available data include global and regional gridded data, images, as well as tabular and vector datasets. In addition to basic visualization and data discovery functionality, users are provided with simple tools for creating customized maps and visualizations and to quantitatively interrogate data. Specialized data portals with advanced functionality are also provided for power users to further analyze data resources and access underlying component datasets. Users may import and analyze their own geospatial datasets by loading local versions of geospatial data and can access content made available through Web Feature Services (WFS) and Web Map Services (WMS). Once data are loaded in GeoMapApp, a variety options are provided to export data and/or 2D/3D

  4. Use of Sine Shaped High-Frequency Rhythmic Visual Stimuli Patterns for SSVEP Response Analysis and Fatigue Rate Evaluation in Normal Subjects.

    Science.gov (United States)

    Keihani, Ahmadreza; Shirzhiyan, Zahra; Farahi, Morteza; Shamsi, Elham; Mahnam, Amin; Makkiabadi, Bahador; Haidari, Mohsen R; Jafari, Amir H

    2018-01-01

    Background: Recent EEG-SSVEP signal based BCI studies have used high frequency square pulse visual stimuli to reduce subjective fatigue. However, the effect of total harmonic distortion (THD) has not been considered. Compared to CRT and LCD monitors, LED screen displays high-frequency wave with better refresh rate. In this study, we present high frequency sine wave simple and rhythmic patterns with low THD rate by LED to analyze SSVEP responses and evaluate subjective fatigue in normal subjects. Materials and Methods: We used patterns of 3-sequence high-frequency sine waves (25, 30, and 35 Hz) to design our visual stimuli. Nine stimuli patterns, 3 simple (repetition of each of above 3 frequencies e.g., P25-25-25) and 6 rhythmic (all of the frequencies in 6 different sequences e.g., P25-30-35) were chosen. A hardware setup with low THD rate ( 90% for CCA and LASSO (for TWs > 1 s). High frequency rhythmic patterns group with low THD rate showed higher accuracy rate (99.24%) than simple patterns group (98.48%). Repeated measure ANOVA showed significant difference between rhythmic pattern features ( P rhythmic [3.85 ± 2.13] compared to the simple patterns group [3.96 ± 2.21], ( P = 0.63). Rhythmic group had lower within group VAS variation (min = P25-30-35 [2.90 ± 2.45], max = P35-25-30 [4.81 ± 2.65]) as well as least individual pattern VAS (P25-30-35). Discussion and Conclusion: Overall, rhythmic and simple pattern groups had higher and similar accuracy rates. Rhythmic stimuli patterns showed insignificantly lower fatigue rate than simple patterns. We conclude that both rhythmic and simple visual high frequency sine wave stimuli require further research for human subject SSVEP-BCI studies.

  5. Visual functions and disability in diabetic retinopathy patients.

    Science.gov (United States)

    Shrestha, Gauri Shankar; Kaiti, Raju

    2014-01-01

    This study was undertaken to find correlations between visual functions and visual disabilities in patients with diabetic retinopathy. A cross-sectional study was carried out among 38 visually impaired diabetic retinopathy subjects at the Low Vision Clinic of B.P. Koirala Lions Centre for Ophthalmic Studies, Kathmandu. The subjects underwent assessment of distance and near visual acuity, objective and subjective refraction, contrast sensitivity, color vision, and central and peripheral visual fields. The visual disabilities of each subject in their daily lives were evaluated using a standard questionnaire. Multiple regression analysis between visual functions and visual disabilities index was assessed. The majority of subjects (42.1%) were of the age group 60-70 years. Best corrected visual acuity was found to be 0.73±0.2 in the better eye and 0.93±0.27 in the worse eye, which was significantly different at p=0.002. Visual disability scores were significantly higher for legibility of letters (1.2±0.3) and sentences (1.4±0.4), and least for clothing (0.7±0.3). Visual disability index for legibility of letters and sentences was significantly correlated with near visual acuity and peripheral visual field. Contrast sensitivity was also significantly correlated with the visual disability index, and total scores. Impairment of near visual acuity, contrast sensitivity, and peripheral visual field correlated significantly with different types of visual disability. Hence, these clinical tests should be an integral part of the visual assessment of diabetic eyes. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  6. Visual bias in subjective assessments of automotive sounds

    DEFF Research Database (Denmark)

    Ellermeier, Wolfgang; Legarth, Søren Vase

    2006-01-01

    In order to evaluate how strong the influence of visual input on sound quality evaluation may be, a naive sample of 20 participants was asked to judge interior automotive sound recordings while simultaneously being exposed to pictures of cars. twenty-two recordings of second-gear acceleration...

  7. Genetic moderation of cocaine subjective effects by variation in the TPH1, TPH2, and SLC6A4 serotonin genes.

    Science.gov (United States)

    Patriquin, Michelle A; Hamon, Sara C; Harding, Mark J; Nielsen, Ellen M; Newton, Thomas F; De La Garza, Richard; Nielsen, David A

    2017-10-01

    This study investigated variants of tryptophan hydroxylase (TPH)1, TPH2, and SLC6A4 in the moderation of the subjective effects of cocaine. Non-treatment-seeking cocaine-dependent individuals (N=66) were intravenously administered saline and cocaine (40 mg) in a randomized order. Participants self-reported subjective effects of cocaine using a visual analog scale starting before administration of saline or cocaine (-15 min) to up to 20 min after infusion. Self-report ratings on the visual analog scale ranged from 0 (no effect) to 100 (greatest effect). Participants were genotyped for the TPH1 rs1799913, TPH2 rs4290270, and SLC6A4 5-HTTLPR variants. Repeated-measures analysis of covariance was used to examine changes in subjective effect scores over time while controlling for population structure. Participants carrying the TPH1 rs1799913 A allele reported greater subjective response to cocaine for 'stimulated' and 'access' relative to the CC genotype group. Those carrying the TPH2 rs4290270 A allele reported higher 'good effect' and lower 'depressed' effect relative to the TT genotype group. Those carrying the SLC6A4 5-HTTLPR S' allele reported greater 'desire' and 'access' compared with the L'L' genotype group. These findings indicate that TPH1, TPH2, and SLC6A4 variants moderate the subjective effects of cocaine in non-treatment-seeking cocaine-dependent participants.

  8. Visual functions and disability in diabetic retinopathy patients

    OpenAIRE

    Shrestha, Gauri Shankar; Kaiti, Raju

    2013-01-01

    Purpose: This study was undertaken to find correlations between visual functions and visual disabilities in patients with diabetic retinopathy. Method: A cross-sectional study was carried out among 38 visually impaired diabetic retinopathy subjects at the Low Vision Clinic of B.P. Koirala Lions Centre for Ophthalmic Studies, Kathmandu. The subjects underwent assessment of distance and near visual acuity, objective and subjective refraction, contrast sensitivity, color vision, and central a...

  9. A new open-source Python-based Space Weather data access, visualization, and analysis toolkit

    Science.gov (United States)

    de Larquier, S.; Ribeiro, A.; Frissell, N. A.; Spaleta, J.; Kunduri, B.; Thomas, E. G.; Ruohoniemi, J.; Baker, J. B.

    2013-12-01

    Space weather research relies heavily on combining and comparing data from multiple observational platforms. Current frameworks exist to aggregate some of the data sources, most based on file downloads via web or ftp interfaces. Empirical models are mostly fortran based and lack interfaces with more useful scripting languages. In an effort to improve data and model access, the SuperDARN community has been developing a Python-based Space Science Data Visualization Toolkit (DaViTpy). At the center of this development was a redesign of how our data (from 30 years of SuperDARN radars) was made available. Several access solutions are now wrapped into one convenient Python interface which probes local directories, a new remote NoSQL database, and an FTP server to retrieve the requested data based on availability. Motivated by the efficiency of this interface and the inherent need for data from multiple instruments, we implemented similar modules for other space science datasets (POES, OMNI, Kp, AE...), and also included fundamental empirical models with Python interfaces to enhance data analysis (IRI, HWM, MSIS...). All these modules and more are gathered in a single convenient toolkit, which is collaboratively developed and distributed using Github and continues to grow. While still in its early stages, we expect this toolkit will facilitate multi-instrument space weather research and improve scientific productivity.

  10. TransVisuality : The Cultural Dimension of Visuality

    DEFF Research Database (Denmark)

    The Transvisuality Project In little more than a decade, visual culture has proven its status and commitment as an independent field of research, drawing on and continuing areas such as art history, cultural studies, semiotics and media research, as well as parts of visual sociology, visual...... for visual culture, transcending a number of disciplinary and geographical borders. The first volume, ‘Boundaries and Creative Openings’, explores the implications of a cultural dimension of ‘visuality’ when seen as a concept reflecting and challenging fundamental aspects of culture, from the arts to social...... anthropology and visual communication. Visual culture is now a well-established academic area of research and teaching, covering subjects in the humanities and social sciences. Readers and introductions have outlined the field, and research is mirrored in networks, journals and conferences on the national...

  11. The New Visual Testimonial: Narrative, Authenticity, and Subjectivity in Emerging Commercial Photographic Practice

    Directory of Open Access Journals (Sweden)

    Heather Morton

    2017-03-01

    Full Text Available By studying the cultural and aesthetic impact of increasingly pervasive digital technologies and mass amateurization, this paper examines the ramifications of the networked information economy on professional photographic practice and considers the concomitant implications for the photographic classroom. Using the framework of convergence culture as per the writings of Yochai Benkler, Henry Jenkins, Mark Deuze, and Axel Bruns, the impact of accessible and instantaneous image creation and dispersal are explored. Given the rise of consumer engagement in brand co-creation on social media platforms, we can observe massive changes to professional practice in areas such as aesthetics, and the erosion of previous sustainable business models. Indeed, as traditional notions of “expertise” shift from technological prowess to narrative and disseminative abilities, the effects on commercial practice and photographic education need to be addressed. This paper argues that there are three emerging priorities for commercial image use: narrative ability, authenticity, and subjectivity and suggests initial steps in their pedagogical application. By acknowledging these transformations, this paper explores the idea that students need to harness technique, social media influence, adaptability, subjectivity, and storytelling power in order to better serve emerging image-based needs in commercial spaces.

  12. [An epidemiological study of visual disability and visual rehabilitation in Beijing].

    Science.gov (United States)

    Zou, Yan-hong; Ding, Ji-yuan; Peng, Hong; Shi, Ji-liang; Qu, Cheng-yi; Liu, Xi-pu

    2009-12-01

    To investigate the status of visual disability and the demands for visual rehabilitation services in Beijing. Five hundred and fifty-five persons with visual disability in Beijing from the Second National Survey on Disability of China were involved in this study. Their visual disability and demands for rehabilitation were evaluated. About three fourth of the visual disabled persons were over 60 years of age. Cataract, retinal and choroidal diseases, and glaucoma were the three leading causes of the visual impairment. Medical service was the number one (82.0%) demand for the persons with visual disability, although 89.4% of them had previously received some kinds of medial services. People who had received visual aid devices or rehabilitation training were 26.7% and 5.8%, respectively, while more people showed their demand for these service (36.6% and 11.9%, respectively). The demand for visual rehabilitation varied in different groups of age and severity of disability. Accessibility of high quality medical services for preventable blindness diseases should be further promoted. Public health education on visual rehabilitation is also needed.

  13. Lateralized visual behavior in bottlenose dolphins (Tursiops truncatus) performing audio-visual tasks: the right visual field advantage.

    Science.gov (United States)

    Delfour, F; Marten, K

    2006-01-10

    Analyzing cerebral asymmetries in various species helps in understanding brain organization. The left and right sides of the brain (lateralization) are involved in different cognitive and sensory functions. This study focuses on dolphin visual lateralization as expressed by spontaneous eye preference when performing a complex cognitive task; we examine lateralization when processing different visual stimuli displayed on an underwater touch-screen (two-dimensional figures, three-dimensional figures and dolphin/human video sequences). Three female bottlenose dolphins (Tursiops truncatus) were submitted to a 2-, 3- or 4-, choice visual/auditory discrimination problem, without any food reward: the subjects had to correctly match visual and acoustic stimuli together. In order to visualize and to touch the underwater target, the dolphins had to come close to the touch-screen and to position themselves using monocular vision (left or right eye) and/or binocular naso-ventral vision. The results showed an ability to associate simple visual forms and auditory information using an underwater touch-screen. Moreover, the subjects showed a spontaneous tendency to use monocular vision. Contrary to previous findings, our results did not clearly demonstrate right eye preference in spontaneous choice. However, the individuals' scores of correct answers were correlated with right eye vision, demonstrating the advantage of this visual field in visual information processing and suggesting a left hemispheric dominance. We also demonstrated that the nature of the presented visual stimulus does not seem to have any influence on the animals' monocular vision choice.

  14. Polarity-Dependent Misperception of Subjective Visual Vertical during and after Transcranial Direct Current Stimulation (tDCS).

    Science.gov (United States)

    Santos-Pontelli, Taiza E G; Rimoli, Brunna P; Favoretto, Diandra B; Mazin, Suleimy C; Truong, Dennis Q; Leite, Joao P; Pontes-Neto, Octavio M; Babyar, Suzanne R; Reding, Michael; Bikson, Marom; Edwards, Dylan J

    2016-01-01

    Pathologic tilt of subjective visual vertical (SVV) frequently has adverse functional consequences for patients with stroke and vestibular disorders. Repetitive transcranial magnetic stimulation (rTMS) of the supramarginal gyrus can produce a transitory tilt on SVV in healthy subjects. However, the effect of transcranial direct current stimulation (tDCS) on SVV has never been systematically studied. We investigated whether bilateral tDCS over the temporal-parietal region could result in both online and offline SVV misperception in healthy subjects. In a randomized, sham-controlled, single-blind crossover pilot study, thirteen healthy subjects performed tests of SVV before, during and after the tDCS applied over the temporal-parietal region in three conditions used on different days: right anode/left cathode; right cathode/left anode; and sham. Subjects were blind to the tDCS conditions. Montage-specific current flow patterns were investigated using computational models. SVV was significantly displaced towards the anode during both active stimulation conditions when compared to sham condition. Immediately after both active conditions, there were rebound effects. Longer lasting after-effects towards the anode occurred only in the right cathode/left anode condition. Current flow models predicted the stimulation of temporal-parietal regions under the electrodes and deep clusters in the posterior limb of the internal capsule. The present findings indicate that tDCS over the temporal-parietal region can significantly alter human SVV perception. This tDCS approach may be a potential clinical tool for the treatment of SVV misperception in neurological patients.

  15. Five Steps to an Accessible Classroom Website

    Science.gov (United States)

    Amundson, Linda

    2009-01-01

    When teachers or technology coordinators publish a website, they are providing a product for a diverse group of people. That's why website design should follow accessibility guidelines. Websites should be accessible to those with visual, hearing, movement, cognitive, and speech disabilities. Good design means greater accessibility for all. This…

  16. Evidence for Non-Opponent Coding of Colour Information in Human Visual Cortex: Selective Loss of "Green" Sensitivity in a Subject with Damaged Ventral Occipito-Temporal Cortex.

    Science.gov (United States)

    Rauscher, Franziska G; Plant, Gordon T; James-Galton, Merle; Barbur, John L

    2011-01-01

    Damage to ventral occipito-temporal extrastriate visual cortex leads to the syndrome of prosopagnosia often with coexisting cerebral achromatopsia. A patient with this syndrome resulting in a left upper homonymous quadrantanopia, prosopagnosia, and incomplete achromatopsia is described. Chromatic sensitivity was assessed at a number of locations in the intact visual field using a dynamic luminance contrast masking technique that isolates the use of colour signals. In normal subjects chromatic detection thresholds form an elliptical contour when plotted in the Commission Internationale d'Eclairage, (x-y), chromaticity diagram. Because the extraction of colour signals in early visual processing involves opponent mechanisms, subjects with Daltonism (congenital red/green loss of sensitivity) show symmetric increase in thresholds towards the long wavelength ("red") and middle wavelength ("green") regions of the spectrum locus. This is also the case with acquired loss of chromatic sensitivity as a result of retinal or optic nerve disease. Our patient's results were an exception to this rule. Whilst his chromatic sensitivity in the central region of the visual field was reduced symmetrically for both "red/green" and "yellow/blue" directions in colour space, the subject's lower left quadrant showed a marked asymmetry in "red/green" thresholds with the greatest loss of sensitivity towards the "green" region of the spectrum locus. This spatially localized asymmetric loss of "green" but not "red" sensitivity has not been reported previously in human vision. Such loss is consistent with selective damage of neural substrates in the visual cortex that process colour information, but are spectrally non-opponent.

  17. Marketing engagement through visual content

    Directory of Open Access Journals (Sweden)

    Marius MANIC

    2015-12-01

    Full Text Available Engaging visual is a must in the modern marketing world. Wide access to mass communication devices, with extended visuals enhancements, made visual content an important point of interest for any publisher, on all media channels. The decreasing costs and huge variety of types are premises for an easy and effective marketing investment, with strong benefits for any company and its brands. Loyal customers are achieved and kept through visual content; the lack of it in the general marketing

  18. Developing Tests of Visual Dependency

    Science.gov (United States)

    Kindrat, Alexandra N.

    2011-01-01

    Astronauts develop neural adaptive responses to microgravity during space flight. Consequently these adaptive responses cause maladaptive disturbances in balance and gait function when astronauts return to Earth and are re-exposed to gravity. Current research in the Neuroscience Laboratories at NASA-JSC is focused on understanding how exposure to space flight produces post-flight disturbances in balance and gait control and developing training programs designed to facilitate the rapid recovery of functional mobility after space flight. In concert with these disturbances, astronauts also often report an increase in their visual dependency during space flight. To better understand this phenomenon, studies were conducted with specially designed training programs focusing on visual dependency with the aim to understand and enhance subjects ability to rapidly adapt to novel sensory situations. The Rod and Frame test (RFT) was used first to assess an individual s visual dependency, using a variety of testing techniques. Once assessed, subjects were asked to perform two novel tasks under transformation (both the Pegboard and Cube Construction tasks). Results indicate that head position cues and initial visual test conditions had no effect on an individual s visual dependency scores. Subjects were also able to adapt to the manual tasks after several trials. Individual visual dependency correlated with ability to adapt manual to a novel visual distortion only for the cube task. Subjects with higher visual dependency showed decreased ability to adapt to this task. Ultimately, it was revealed that the RFT may serve as an effective prediction tool to produce individualized adaptability training prescriptions that target the specific sensory profile of each crewmember.

  19. The value of filmed interviews: issues of visualization, visual transcrips and the reading of visual texts

    NARCIS (Netherlands)

    Witteveen, L.; Lie, R.

    2013-01-01

    The increased access to video technology advances the use of visual methodologies in research. Following these developments, researchers are confronted with new challenges. Video recordings of interviews, as compared to audio recordings, are gaining interest in qualitative field research in the

  20. Impact of a Braille-Note on Writing: Evaluating the Process, Quality, and Attitudes of Three Students Who Are Visually Impaired

    Science.gov (United States)

    Kamei-Hannan, Cheryl; Lawson, Holly

    2012-01-01

    Educators of students with visual impairments have long advocated that children who read and write in braille benefit from access to and use of a braille note-taker (BNT) with refreshable braille display. However, little research exists that evaluates whether using a BNT impacts literacy. In this single-subject study, authors investigated if using…

  1. Estudio sobre el software libre orientado a personas con discapacidad visual

    OpenAIRE

    Palomá Parra, Esaú

    2015-01-01

    Se pretende realizar un estudio sobre las herramientas TIC accesibles a las personas con discapacidad visual, que permita sugerir el diseño de un sistema universal accesible orientado a personas con discapacidad visual. Es pretén realitzar un estudi sobre les eines TIC accessibles a les persones amb discapacitat visual, que permeti suggerir el disseny d'un sistema universal accessible orientat a persones amb discapacitat visual. Master thesis for the Free Software program.

  2. Analysis of visual appearance of retinal nerve fibers in high resolution fundus images: a study on normal subjects.

    Science.gov (United States)

    Kolar, Radim; Tornow, Ralf P; Laemmer, Robert; Odstrcilik, Jan; Mayer, Markus A; Gazarek, Jiri; Jan, Jiri; Kubena, Tomas; Cernosek, Pavel

    2013-01-01

    The retinal ganglion axons are an important part of the visual system, which can be directly observed by fundus camera. The layer they form together inside the retina is the retinal nerve fiber layer (RNFL). This paper describes results of a texture RNFL analysis in color fundus photographs and compares these results with quantitative measurement of RNFL thickness obtained from optical coherence tomography on normal subjects. It is shown that local mean value, standard deviation, and Shannon entropy extracted from the green and blue channel of fundus images are correlated with corresponding RNFL thickness. The linear correlation coefficients achieved values 0.694, 0.547, and 0.512 for respective features measured on 439 retinal positions in the peripapillary area from 23 eyes of 15 different normal subjects.

  3. Perceptions, Attitudes and Institutional Factors That Influence Academic Performance of Visual Arts Students in Ghana's Senior High School Core Curriculum Subjects

    Science.gov (United States)

    Opoku-Asare, Nana Afia; Tachie-Menson, Akosua; Essel, Harry Barton

    2015-01-01

    Senior High School (SHS) students in Ghana are required to pass all core and elective curricula subjects in the West Africa Senior School Certificate Examination (WASSCE) to qualify for higher education. Unfortunately, many Visual Arts students perform poorly or fail in English, Mathematics, Integrated Science and Social Studies, which constitute…

  4. Bilingual visual word recognition and lexical access

    NARCIS (Netherlands)

    Dijkstra, A.F.J.; Kroll, J.F.; Groot, A.M.B. de

    2005-01-01

    In spite of the intuition of many bilinguals, a review of empirical studies indicates that during reading under many circumstances, possible words from different languages temporarily become active. Such evidence for "language non-selective lexical access" is found using stimulus materials of

  5. Distributed data discovery, access and visualization services to Improve Data Interoperability across different data holdings

    Science.gov (United States)

    Palanisamy, G.; Krassovski, M.; Devarakonda, R.; Santhana Vannan, S.

    2012-12-01

    The current climate debate is highlighting the importance of free, open, and authoritative sources of high quality climate data that are available for peer review and for collaborative purposes. It is increasingly important to allow various organizations around the world to share climate data in an open manner, and to enable them to perform dynamic processing of climate data. This advanced access to data can be enabled via Web-based services, using common "community agreed" standards without having to change their internal structure used to describe the data. The modern scientific community has become diverse and increasingly complex in nature. To meet the demands of such diverse user community, the modern data supplier has to provide data and other related information through searchable, data and process oriented tool. This can be accomplished by setting up on-line, Web-based system with a relational database as a back end. The following common features of the web data access/search systems will be outlined in the proposed presentation: - A flexible data discovery - Data in commonly used format (e.g., CSV, NetCDF) - Preparing metadata in standard formats (FGDC, ISO19115, EML, DIF etc.) - Data subseting capabilities and ability to narrow down to individual data elements - Standards based data access protocols and mechanisms (SOAP, REST, OpenDAP, OGC etc.) - Integration of services across different data systems (discovery to access, visualizations and subseting) This presentation will also include specific examples of integration of various data systems that are developed by Oak Ridge National Laboratory's - Climate Change Science Institute, their ability to communicate between each other to enable better data interoperability and data integration. References: [1] Devarakonda, Ranjeet, and Harold Shanafield. "Drupal: Collaborative framework for science research." Collaboration Technologies and Systems (CTS), 2011 International Conference on. IEEE, 2011. [2

  6. Visual Access in Interpreter-Mediated Learning Situations for Deaf and Hard-of-Hearing High School Students Where an Artifact Is in Use

    Science.gov (United States)

    Thomassen, Gøril

    2016-01-01

    This article highlights interpreter-mediated learning situations for deaf high school students where such mediated artifacts as technical machines, models, and computer graphics are used by the teacher to illustrate his or her teaching. In these situations, the teacher’s situated gestures and utterances, and the artifacts will contribute independent pieces of information. However, the deaf student can only have his or her visual attention focused on one source at a time. The problem to be addressed is how the interpreter coordinates the mediation when it comes to deaf students’ visual orientation. The presented discourse analysis is based on authentic video recordings from inclusive learning situations in Norway. The theoretical framework consists of concepts of role, footing, and face-work (Goffman, E. (1959). The presentation of self in everyday life. London, UK: Penguin Books). The findings point out dialogical impediments to visual access in interpreter-mediated learning situations, and the article discusses the roles and responsibilities of teachers and educational interpreters. PMID:26681267

  7. White matter damage impairs access to consciousness in multiple sclerosis.

    Science.gov (United States)

    Reuter, Françoise; Del Cul, Antoine; Malikova, Irina; Naccache, Lionel; Confort-Gouny, Sylviane; Cohen, Laurent; Cherif, André Ali; Cozzone, Patrick J; Pelletier, Jean; Ranjeva, Jean-Philippe; Dehaene, Stanislas; Audoin, Bertrand

    2009-01-15

    Global neuronal workspace theory predicts that damage to long-distance white matter (WM) tracts should impair access to consciousness during the perception of brief stimuli. To address this issue, we studied visual backward masking in 18 patients at the very first clinical stage of multiple sclerosis (MS), a neurological disease characterized by extensive WM damage, and in 18 matched healthy subjects. In our masking paradigm, the visibility of a digit stimulus increases non-linearly as a function of the interval duration between this target and a subsequent mask. In order to characterize quantitatively, for each subject, the transition between non-conscious and conscious perception of the stimulus, we used non-linear regression to fit a sigmoid curve to objective performance and subjective visibility reports as a function of target-mask delay. The delay corresponding to the inflexion point of the sigmoid, where visibility suddenly increases, was termed the "non-linear transition threshold" and used as a summary measure of masking efficiency. Objective and subjective non-linear transition thresholds were highly correlated across subjects in both groups, and were higher in patients compared to controls. In patients, variations in the non-linear transition threshold were inversely correlated to the Magnetization transfer ratio (MTR) values inside the right dorsolateral prefrontal WM, the right occipito-frontal fasciculus and the left cerebellum. This study provides clinical evidence of a relationship between impairments of conscious access and integrity of large WM bundles, particularly involving prefrontal cortex, as predicted by global neuronal workspace theory.

  8. Visually induced reorientation illusions

    Science.gov (United States)

    Howard, I. P.; Hu, G.; Oman, C. M. (Principal Investigator)

    2001-01-01

    It is known that rotation of a furnished room around the roll axis of erect subjects produces an illusion of 360 degrees self-rotation in many subjects. Exposure of erect subjects to stationary tilted visual frames or rooms produces only up to 20 degrees of illusory tilt. But, in studies using static tilted rooms, subjects remained erect and the body axis was not aligned with the room. We have revealed a new class of disorientation illusions that occur in many subjects when placed in a 90 degrees or 180 degrees tilted room containing polarised objects (familiar objects with tops and bottoms). For example, supine subjects looking up at a wall of the room feel upright in an upright room and their arms feel weightless when held out from the body. We call this the levitation illusion. We measured the incidence of 90 degrees or 180 degrees reorientation illusions in erect, supine, recumbent, and inverted subjects in a room tilted 90 degrees or 180 degrees. We report that reorientation illusions depend on the displacement of the visual scene rather than of the body. However, illusions are most likely to occur when the visual and body axes are congruent. When the axes are congruent, illusions are least likely to occur when subjects are prone rather than supine, recumbent, or inverted.

  9. Visual Evoked Response in Children Subjected to Prenatal Maternal ...

    African Journals Online (AJOL)

    neural conduction, or arousal level. S. Afr. Med. J., 48 ... pression treatment in either development or IQ, whether ... children in brain function at an electrophysiological level, ..... Perry, N. W. and Childers, D. G. (1969): The Human Visual Evoked.

  10. Spatial limits on the nonvisual self-touch illusion and the visual rubber hand illusion: subjective experience of the illusion and proprioceptive drift.

    Science.gov (United States)

    Aimola Davies, Anne M; White, Rebekah C; Davies, Martin

    2013-06-01

    The nonvisual self-touch rubber hand paradigm elicits the compelling illusion that one is touching one's own hand even though the two hands are not in contact. In four experiments, we investigated spatial limits of distance (15 cm, 30 cm, 45 cm, 60 cm) and alignment (0°, 90° anti-clockwise) on the nonvisual self-touch illusion and the well-known visual rubber hand illusion. Common procedures (synchronous and asynchronous stimulation administered for 60s with the prosthetic hand at body midline) and common assessment methods were used. Subjective experience of the illusion was assessed by agreement ratings for statements on a questionnaire and time of illusion onset. The nonvisual self-touch illusion was diminished though never abolished by distance and alignment manipulations, whereas the visual rubber hand illusion was more robust against these manipulations. We assessed proprioceptive drift, and implications of a double dissociation between subjective experience of the illusion and proprioceptive drift are discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Vividness of visual imagery and incidental recall of verbal cues, when phenomenological availability reflects long-term memory accessibility

    Directory of Open Access Journals (Sweden)

    Amedeo eD'Angiulli

    2013-02-01

    Full Text Available The relationship between vivid visual mental images and unexpected recall (incidental recall was replicated, refined and extended. In Experiment 1, participants were asked to generate mental images from imagery-evoking verbal-cues (controlled on several verbal properties and then, on a trial-by-trial basis, rate the vividness of their images; thirty minutes later, participants were surprised with a task requiring free recall of the cues. Higher vividness ratings predicted better incidental recall of the cues than individual differences (whose effect was modest. Distributional analysis of image latencies through ex-Gaussian modeling showed an inverse relation between vividness and latency. However, recall was unrelated to image latency. The follow-up Experiment 2 showed that the processes underlying trial-by-trial vividness ratings are unrelated to the Vividness of Visual Imagery Questionnaire (VVIQ, as further supported by a meta-analysis of a randomly selected sample of relevant literature. The present findings suggest that vividness may act as an index of availability of long-term sensory traces, playing a non-epiphenomenal role in facilitating the access of those memories.

  12. Vividness of visual imagery and incidental recall of verbal cues, when phenomenological availability reflects long-term memory accessibility.

    Science.gov (United States)

    D'Angiulli, Amedeo; Runge, Matthew; Faulkner, Andrew; Zakizadeh, Jila; Chan, Aldrich; Morcos, Selvana

    2013-01-01

    The relationship between vivid visual mental images and unexpected recall (incidental recall) was replicated, refined, and extended. In Experiment 1, participants were asked to generate mental images from imagery-evoking verbal cues (controlled on several verbal properties) and then, on a trial-by-trial basis, rate the vividness of their images; 30 min later, participants were surprised with a task requiring free recall of the cues. Higher vividness ratings predicted better incidental recall of the cues than individual differences (whose effect was modest). Distributional analysis of image latencies through ex-Gaussian modeling showed an inverse relation between vividness and latency. However, recall was unrelated to image latency. The follow-up Experiment 2 showed that the processes underlying trial-by-trial vividness ratings are unrelated to the Vividness of Visual Imagery Questionnaire (VVIQ), as further supported by a meta-analysis of a randomly selected sample of relevant literature. The present findings suggest that vividness may act as an index of availability of long-term sensory traces, playing a non-epiphenomenal role in facilitating the access of those memories.

  13. Analysis of Visual Appearance of Retinal Nerve Fibers in High Resolution Fundus Images: A Study on Normal Subjects

    Directory of Open Access Journals (Sweden)

    Radim Kolar

    2013-01-01

    Full Text Available The retinal ganglion axons are an important part of the visual system, which can be directly observed by fundus camera. The layer they form together inside the retina is the retinal nerve fiber layer (RNFL. This paper describes results of a texture RNFL analysis in color fundus photographs and compares these results with quantitative measurement of RNFL thickness obtained from optical coherence tomography on normal subjects. It is shown that local mean value, standard deviation, and Shannon entropy extracted from the green and blue channel of fundus images are correlated with corresponding RNFL thickness. The linear correlation coefficients achieved values 0.694, 0.547, and 0.512 for respective features measured on 439 retinal positions in the peripapillary area from 23 eyes of 15 different normal subjects.

  14. Altered visual information processing systems in bipolar disorder: evidence from visual MMN and P3

    Directory of Open Access Journals (Sweden)

    Toshihiko eMaekawa

    2013-07-01

    Full Text Available Objective: Mismatch negativity (MMN and P3 are unique ERP components that provide objective indices of human cognitive functions such as short-term memory and prediction. Bipolar disorder (BD is an endogenous psychiatric disorder characterized by extreme shifts in mood, energy, and ability to function socially. BD patients usually show cognitive dysfunction, and the goal of this study was to access their altered visual information processing via visual MMN (vMMN and P3 using windmill pattern stimuli.Methods: Twenty patients with BD and 20 healthy controls matched for age, gender, and handedness participated in this study. Subjects were seated in front of a monitor and listened to a story via earphones. Two types of windmill patterns (standard and deviant and white circle (target stimuli were randomly presented on the monitor. All stimuli were presented in random order at 200-ms durations with an 800-ms inter-stimulus interval. Stimuli were presented at 80% (standard, 10% (deviant, and 10% (target probabilities. The participants were instructed to attend to the story and press a button as soon as possible when the target stimuli were presented. Event-related potentials were recorded throughout the experiment using 128-channel EEG equipment. vMMN was obtained by subtracting standard from deviant stimuli responses, and P3 was evoked from the target stimulus.Results: Mean reaction times for target stimuli in the BD group were significantly higher than those in the control group. Additionally, mean vMMN-amplitudes and peak P3-amplitudes were significantly lower in the BD group than in controls.Conclusions: Abnormal vMMN and P3 in patients indicate a deficit of visual information processing in bipolar disorder, which is consistent with their increased reaction time to visual target stimuli.Significance: Both bottom-up and top-down visual information processing are likely altered in BD.

  15. Effects of Visual Feedback Distortion on Gait Adaptation: Comparison of Implicit Visual Distortion Versus Conscious Modulation on Retention of Motor Learning.

    Science.gov (United States)

    Kim, Seung-Jae; Ogilvie, Mitchell; Shimabukuro, Nathan; Stewart, Trevor; Shin, Joon-Ho

    2015-09-01

    Visual feedback can be used during gait rehabilitation to improve the efficacy of training. We presented a paradigm called visual feedback distortion; the visual representation of step length was manipulated during treadmill walking. Our prior work demonstrated that an implicit distortion of visual feedback of step length entails an unintentional adaptive process in the subjects' spatial gait pattern. Here, we investigated whether the implicit visual feedback distortion, versus conscious correction, promotes efficient locomotor adaptation that relates to greater retention of a task. Thirteen healthy subjects were studied under two conditions: (1) we implicitly distorted the visual representation of their gait symmetry over 14 min, and (2) with help of visual feedback, subjects were told to walk on the treadmill with the intent of attaining the gait asymmetry observed during the first implicit trial. After adaptation, the visual feedback was removed while subjects continued walking normally. Over this 6-min period, retention of preserved asymmetric pattern was assessed. We found that there was a greater retention rate during the implicit distortion trial than that of the visually guided conscious modulation trial. This study highlights the important role of implicit learning in the context of gait rehabilitation by demonstrating that training with implicit visual feedback distortion may produce longer lasting effects. This suggests that using visual feedback distortion could improve the effectiveness of treadmill rehabilitation processes by influencing the retention of motor skills.

  16. Visual Short-Term Memory Complexity

    DEFF Research Database (Denmark)

    Sørensen, Thomas Alrik

    of objective complexity, it seems that subjective complexity - which is dependent on the familiarity of the stimulus - plays a more important role than the objective visual complexity of the objects stored. In two studies, we explored how familiarity influences the capacity of VSTM. 1) In children learning...... and Cavanagh (2004) have raised the question that the capacity of VSTM is dependent on visual complexity rather than the number of objects. We hypothesise that VSTM capacity is dependent on both the objective and subjective complexity of visual stimuli. Contrary to Alvarez and Cavanagh, who argue for the role...... for letters and pictures remained similar. Our results indicate that VSTM capacity for familiar items is larger irrespective of visual complexity....

  17. Food experiences and eating patterns of visually impaired and blind people.

    Science.gov (United States)

    Bilyk, Marie Claire; Sontrop, Jessica M; Chapman, Gwen E; Barr, Susan I; Mamer, Linda

    2009-01-01

    The number of visually impaired and blind Canadians will rise dramatically as our population ages, and yet little is known about the impact of blindness on the experience of food and eating. In this qualitative study, the food experiences and eating patterns of visually impaired and blind people were examined. Influencing factors were also explored. In 2000, nine blind or severely visually impaired subjects were recruited through blindness-related organizations in British Columbia. Participants completed individual semi-structured, in-depth interviews. These were transcribed verbatim, coded, and analyzed to explicate participants' experiences. Participants experienced blindness-related obstacles when shopping for food, preparing food, and eating in restaurants. Inaccessible materials and environments left participants with a diet lacking in variety and limited access to physical activity. Seven participants were overweight or obese, a finding that may be related to limited physical activity and higher-than-average restaurant use. This is the first study in which the experience of food and eating is described from the perspective of visually impaired Canadians. Nutrition and blindness professionals must work together to reduce the food-related obstacles faced by visually impaired and blind people. Professionals must address both individual skill development and social and structural inequities.

  18. Peripheral visual response time and visual display layout

    Science.gov (United States)

    Haines, R. F.

    1974-01-01

    Experiments were performed on a group of 42 subjects in a study of their peripheral visual response time to visual signals under positive acceleration, during prolonged bedrest, at passive 70 deg headup body lift, under exposures to high air temperatures and high luminance levels, and under normal stress-free laboratory conditions. Diagrams are plotted for mean response times to white, red, yellow, green, and blue stimuli under different conditions.

  19. A service-oriented data access control model

    Science.gov (United States)

    Meng, Wei; Li, Fengmin; Pan, Juchen; Song, Song; Bian, Jiali

    2017-01-01

    The development of mobile computing, cloud computing and distributed computing meets the growing individual service needs. Facing with complex application system, it's an urgent problem to ensure real-time, dynamic, and fine-grained data access control. By analyzing common data access control models, on the basis of mandatory access control model, the paper proposes a service-oriented access control model. By regarding system services as subject and data of databases as object, the model defines access levels and access identification of subject and object, and ensures system services securely to access databases.

  20. Cognitive and psychological science insights to improve climate change data visualization

    Science.gov (United States)

    Harold, Jordan; Lorenzoni, Irene; Shipley, Thomas F.; Coventry, Kenny R.

    2016-12-01

    Visualization of climate data plays an integral role in the communication of climate change findings to both expert and non-expert audiences. The cognitive and psychological sciences can provide valuable insights into how to improve visualization of climate data based on knowledge of how the human brain processes visual and linguistic information. We review four key research areas to demonstrate their potential to make data more accessible to diverse audiences: directing visual attention, visual complexity, making inferences from visuals, and the mapping between visuals and language. We present evidence-informed guidelines to help climate scientists increase the accessibility of graphics to non-experts, and illustrate how the guidelines can work in practice in the context of Intergovernmental Panel on Climate Change graphics.

  1. Staging Visual Methods

    DEFF Research Database (Denmark)

    Flensborg, Ingelise

    2009-01-01

    A visual methodological approach of exploring postures and movemenets in young childrens communication with art. How do we translate bodily postures and movements into methodological categories to access data of the interactive processes? These issues will be discussed through video matrials...

  2. Accessible Web Design - The Power of the Personal Message.

    Science.gov (United States)

    Whitney, Gill

    2015-01-01

    The aim of this paper is to describe ongoing research being carried out to enable people with visual impairments to communicate directly with designers and specifiers of hobby and community web sites to maximise the accessibility of their sites. The research started with an investigation of the accessibility of community and hobby web sites as perceived by a group of visually impaired end users. It is continuing with an investigation into how to best to communicate with web designers who are not experts in web accessibility. The research is making use of communication theory to investigate how terminology describing personal experience can be used in the most effective and powerful way. By working with the users using a Delphi study the research has ensured that the views of the visually impaired end users is successfully transmitted.

  3. Visiting Richard Serra’s Promenade sculpture improves postural control and judgment of subjective visual vertical.

    Directory of Open Access Journals (Sweden)

    Zoï eKapoula

    2014-12-01

    Full Text Available Body sway while maintaining an upright quiet stance reflects an active process of balance based on the integration of visual, vestibular, somatosensory and proprioceptive inputs. Richard Serra’s Promenade sculpture featured in the 2008 Monumenta exhibition at the Grand Palais in Paris, France is herein hypothesised to have stimulated the body’s vertical and longitudinal axes as it showcased 5 monumental rectangular solids pitched at a 1.69° angle.Using computerised dynamic posturography we measured the body sway of 23 visitors when fixating a cross, or when observing the artwork (fixating it or actively exploring it with eye movements before and after walking around and alongside the sculpture (i.e., before and after a promenade. A first fixation at the sculpture increased medio-lateral stability (in terms of spectral power of body sway. Eye movement exploration in the depth of the sculpture increased antero-posterior stability (in terms of spectral power and cancelling time of body sway at the expense of medio-lateral stability (in terms of cancelling time. Moreover, a medio-lateral instability associated with eye movement exploration before the promenade (in terms of body sway sensu stricto was cancelled after the promenade. Finally, the overall medio-lateral stability (in terms of spectral power increased after the promenade.Fourteen additional visitors were asked to sit in a dark room and adjust a luminous line to what they considered to be the earth-vertical axis. The promenade executed within the sculpted environment afforded by Serra’s monumental statuary works resulted in significantly improved performances on the subjective visual vertical test.We attribute these effects to the sculpted environment provided by the exhibition which may have acted as a kind of physiologic training ground thereby improving the visitors’ overall sense of visual perspective, equilibrium and gravity.

  4. Scientific Production on Open Access: A Worldwide Bibliometric Analysis in the Academic and Scientific Context

    Directory of Open Access Journals (Sweden)

    Sandra Miguel

    2016-01-01

    Full Text Available This research aims to diachronically analyze the worldwide scientific production on open access, in the academic and scientific context, in order to contribute to knowledge and visualization of its main actors. As a method, bibliographical, descriptive and analytical research was used, with the contribution of bibliometric studies, especially the production indicators, scientific collaboration and indicators of thematic co-occurrence. The Scopus database was used as a source to retrieve the articles on the subject, with a resulting corpus of 1179 articles. Using Bibexcel software, frequency tables were constructed for the variables, and Pajek software was used to visualize the collaboration network and VoSViewer for the construction of the keywords’ network. As for the results, the most productive researchers come from countries such as the United States, Canada, France and Spain. Journals with higher impact in the academic community have disseminated the new constructed knowledge. A collaborative network with a few subnets where co-authors are from different countries has been observed. As conclusions, this study allows identifying the themes of debates that mark the development of open access at the international level, and it is possible to state that open access is one of the new emerging and frontier fields of library and information science.

  5. RCSB PDB Mobile: iOS and Android mobile apps to provide data access and visualization to the RCSB Protein Data Bank.

    Science.gov (United States)

    Quinn, Gregory B; Bi, Chunxiao; Christie, Cole H; Pang, Kyle; Prlić, Andreas; Nakane, Takanori; Zardecki, Christine; Voigt, Maria; Berman, Helen M; Bourne, Philip E; Rose, Peter W

    2015-01-01

    The Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB) resource provides tools for query, analysis and visualization of the 3D structures in the PDB archive. As the mobile Web is starting to surpass desktop and laptop usage, scientists and educators are beginning to integrate mobile devices into their research and teaching. In response, we have developed the RCSB PDB Mobile app for the iOS and Android mobile platforms to enable fast and convenient access to RCSB PDB data and services. Using the app, users from the general public to expert researchers can quickly search and visualize biomolecules, and add personal annotations via the RCSB PDB's integrated MyPDB service. RCSB PDB Mobile is freely available from the Apple App Store and Google Play (http://www.rcsb.org). © The Author 2014. Published by Oxford University Press.

  6. Visual Education

    DEFF Research Database (Denmark)

    Buhl, Mie; Flensborg, Ingelise

    2010-01-01

    The intrinsic breadth of various types of images creates new possibilities and challenges for visual education. The digital media have moved the boundaries between images and other kinds of modalities (e.g. writing, speech and sound) and have augmented the possibilities for integrating the functi......The intrinsic breadth of various types of images creates new possibilities and challenges for visual education. The digital media have moved the boundaries between images and other kinds of modalities (e.g. writing, speech and sound) and have augmented the possibilities for integrating...... to emerge in the interlocutory space of a global visual repertoire and diverse local interpretations. The two perspectives represent challenges for future visual education which require visual competences, not only within the arts but also within the subjects of natural sciences, social sciences, languages...

  7. Visual Communications for Heterogeneous Networks/Visually Optimized Scalable Image Compression. Final Report for September 1, 1995 - February 28, 2002

    Energy Technology Data Exchange (ETDEWEB)

    Hemami, S. S.

    2003-06-03

    The authors developed image and video compression algorithms that provide scalability, reconstructibility, and network adaptivity, and developed compression and quantization strategies that are visually optimal at all bit rates. The goal of this research is to enable reliable ''universal access'' to visual communications over the National Information Infrastructure (NII). All users, regardless of their individual network connection bandwidths, qualities-of-service, or terminal capabilities, should have the ability to access still images, video clips, and multimedia information services, and to use interactive visual communications services. To do so requires special capabilities for image and video compression algorithms: scalability, reconstructibility, and network adaptivity. Scalability allows an information service to provide visual information at many rates, without requiring additional compression or storage after the stream has been compressed the first time. Reconstructibility allows reliable visual communications over an imperfect network. Network adaptivity permits real-time modification of compression parameters to adjust to changing network conditions. Furthermore, to optimize the efficiency of the compression algorithms, they should be visually optimal, where each bit expended reduces the visual distortion. Visual optimality is achieved through first extensive experimentation to quantify human sensitivity to supra-threshold compression artifacts and then incorporation of these experimental results into quantization strategies and compression algorithms.

  8. Visual impairment and spectacle coverage rate in Baoshan district, China: population-based study

    Science.gov (United States)

    2013-01-01

    Background To investigate the prevalence and risk factors of visual impairment associated with refractive error and the unmet need for spectacles in a special suburban senior population in Baoshan District of Shanghai, one of several rural areas undergoing a transition from rural to urban area, where data of visual impairment are limited. Methods The study was a population based survey of 4545 Chinese aged (age: >60 years or older ) at Baoshan, Shanghai, in 2009. One copy of questionnaire was completed for each subject. Examinations included a standardized refraction and measurement of presenting and best corrected visual acuity (BCVA) as well as tonometry, slit lamp biomicroscopy, and fundus photography. Results The prevalence of mild (6/12 to 6/18), moderate (6/18 to 6/60) and severe visual impairment was 12.59%, 8.38% and 0.44%, respectively, and 5.26%, 3.06% and 0.09% with refractive correction. Visual impairment was associated with age, gender, education and career, but not insurance . The prevalence of correctable visual impairment was 5.81% (using 6/18 cutoff) and 13.18% (using 6/12 cutoff). Senior people and women were significantly at a higher risk of correctable visual impairment, while the well-educated on the contrary. The prevalence of undercorrected refractive error (improves by 2 or more lines with refraction) was 24.84%, and the proportion with undercorrected refractive error for mild, moderate , severe and no visual impairment was 61.54%, 67.98%, 60.00% and 14.10%, respectively. The spectacle coverage rate was 44.12%. Greater unmet need for spectacles was observed among elderly people, females, non-peasant, and subjects with less education and astigmatism only. Conclusions High prevalence of visual impairment, visual impairment alleviated by refractive correction, and low spectacle coverage existed among the senior population in Baoshan District of Shanghai. Education for the public of the importance of regular examination and appropriate and

  9. Visual Access in Interpreter-Mediated Learning Situations for Deaf and Hard-of-Hearing High School Students Where an Artifact Is in Use.

    Science.gov (United States)

    Berge, Sigrid Slettebakk; Thomassen, Gøril

    2016-04-01

    This article highlights interpreter-mediated learning situations for deaf high school students where such mediated artifacts as technical machines, models, and computer graphics are used by the teacher to illustrate his or her teaching. In these situations, the teacher's situated gestures and utterances, and the artifacts will contribute independent pieces of information. However, the deaf student can only have his or her visual attention focused on one source at a time. The problem to be addressed is how the interpreter coordinates the mediation when it comes to deaf students' visual orientation. The presented discourse analysis is based on authentic video recordings from inclusive learning situations in Norway. The theoretical framework consists of concepts of role, footing, and face-work (Goffman, E. (1959). The presentation of self in everyday life. London, UK: Penguin Books). The findings point out dialogical impediments to visual access in interpreter-mediated learning situations, and the article discusses the roles and responsibilities of teachers and educational interpreters. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Vision as subjective perception

    International Nuclear Information System (INIS)

    Reppas, J.B.; Dale, A.; Sereno, M.; Tootell, R.

    1996-01-01

    The human brain is not very different of the monkey's one: at least, its visual cortex is organized as a similar scheme. Specialized areas in the movement analysis are found and others in the forms perception. In this work, the author tries to answer to the following questions: 1)why so many visual areas? What are exactly their role in vision? Thirteen years of experimentation have not allowed to answer to these questions. The cerebral NMR imaging gives the opportunity of understanding the subjective perception of the visual world. One step which is particularly described in this work is to know how the visual cortex reacts to the optical illusions. (O.M.)

  11. Multi-tool accessibility assessment of government department websites:a case-study with JKGAD.

    Science.gov (United States)

    Ismail, Abid; Kuppusamy, K S; Nengroo, Ab Shakoor

    2017-08-02

    Nature of being accessible to all categories of users is one of the primary factors for enabling the wider reach of the resources published through World Wide Web. The accessibility of websites has been analyzed through W3C guidelines with the help of various tools. This paper presents a multi-tool accessibility assessment of government department websites belonging to the Indian state of Jammu and Kashmir. A comparative analysis of six accessibility tools is also presented with 14 different parameters. The accessibility analysis tools used in this study for analysis are aChecker, Cynthia Says, Tenon, wave, Mauve, and Hera. These tools provide us the results of selected websites accessibility status on Web Content Accessibility Guidelines (WCAG) 1.0 and 2.0. It was found that there are variations in accessibility analysis results when using different accessibility metrics to measure the accessibility of websites. In addition to this, we have identified the guidelines which have frequently been violated. It was observed that there is a need for incorporating the accessibility component features among the selected websites. This paper presents a set of suggestions to improve the accessibility status of these sites so that the information and services provided by these sites shall reach a wider spectrum of audience without any barrier. Implications for rehabilitation The following points indicates that this case study of JKGAD websites comes under Rehabilitation focused on Visually Impaired users. Due to the universal nature of web, it should be accessible to all according to WCAG guidelines framed by World Wide Web Consortium. In this paper we have identified multiple accessibility barriers for persons with visual impairment while browsing the Jammu and Kashmir Government websites. Multi-tool analysis has been done to pin-point the potential barriers for persons with visually Impaired. Usability analysis has been performed to check whether these websites are suitable

  12. Visual impairment, but not hearing impairment, is independently associated with lower subjective well-being among individuals over 95 years of age: A population-based study.

    Science.gov (United States)

    Liu, Zuyun; Wu, Di; Huang, Jiapin; Qian, Degui; Chen, Fei; Xu, Jun; Li, Shilin; Jin, Li; Wang, Xiaofeng

    2016-01-01

    Sensory impairment affects an increasing number of elderly adults, with a negative psychological impact. Our objective was to examine the associations of visual and hearing impairment with subjective well-being (SWB), an important psychological concept defined by life satisfaction [LS], positive affect [PA], negative affect [NA], and affect balance [AB] among long-lived individuals (LLIs) over 95 years of age. Data on 442 LLIs from the Rugao longevity cohort, a population-based study in Rugao, China, were analyzed. Graded classifications of visual and hearing impairment (none, mild, moderate, and severe) were constructed from self-reported items. Bivariate correlation and multiple regression analysis were performed to test the associations. Approximately 66.1% and 87.3% of the subjects reported varying degrees of visual and hearing impairment. Following the degree of vision impairment, LS, PA, and AB decreased linearly, whereas NA increased linearly (all p for trendimpairment with LS, NA, and AB, while diminished, still existed. Visual impairment, but not hearing impairment, was independently associated with low SWB among LLIs, and functional ability may play a mediating role in the observed relationship. The findings indicate that rehabilitation targeted for those with reduced vision and functioning in long-lived populations may be important for promoting well-being and quality of life. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Social inequalities in blindness and visual impairment: A review of social determinants

    Directory of Open Access Journals (Sweden)

    Anna Rius

    2012-01-01

    Full Text Available Health inequities are related to social determinants based on gender, socioeconomic status, ethnicity, race, living in a specific geographic region, or having a specific health condition. Such inequities were reviewed for blindness and visual impairment by searching for studies on the subject in PubMed from 2000 to 2011 in the English and Spanish languages. The goal of this article is to provide a current review in understanding how inequities based specifically on the aforementioned social determinants on health influence the prevalence of visual impairment and blindness. With regards to gender inequality, women have a higher prevalence of visual impairment and blindness, which cannot be only reasoned based on age or access to service. Socioeconomic status measured as higher income, higher educational status, or non-manual occupational social class was inversely associated with prevalence of blindness or visual impairment. Ethnicity and race were associated with visual impairment and blindness, although there is general confusion over this socioeconomic position determinant. Geographic inequalities and visual impairment were related to income (of the region, nation or continent, living in a rural area, and an association with socioeconomic and political context was suggested. While inequalities related to blindness and visual impairment have rarely been specifically addressed in research, there is still evidence of the association of social determinants and prevalence of blindness and visual impairment. Additional research should be done on the associations with intermediary determinants and socioeconomic and political context.

  14. Social inequalities in blindness and visual impairment: A review of social determinants

    Science.gov (United States)

    Ulldemolins, Anna Rius; Lansingh, Van C; Valencia, Laura Guisasola; Carter, Marissa J; Eckert, Kristen A

    2012-01-01

    Health inequities are related to social determinants based on gender, socioeconomic status, ethnicity, race, living in a specific geographic region, or having a specific health condition. Such inequities were reviewed for blindness and visual impairment by searching for studies on the subject in PubMed from 2000 to 2011 in the English and Spanish languages. The goal of this article is to provide a current review in understanding how inequities based specifically on the aforementioned social determinants on health influence the prevalence of visual impairment and blindness. With regards to gender inequality, women have a higher prevalence of visual impairment and blindness, which cannot be only reasoned based on age or access to service. Socioeconomic status measured as higher income, higher educational status, or non-manual occupational social class was inversely associated with prevalence of blindness or visual impairment. Ethnicity and race were associated with visual impairment and blindness, although there is general confusion over this socioeconomic position determinant. Geographic inequalities and visual impairment were related to income (of the region, nation or continent), living in a rural area, and an association with socioeconomic and political context was suggested. While inequalities related to blindness and visual impairment have rarely been specifically addressed in research, there is still evidence of the association of social determinants and prevalence of blindness and visual impairment. Additional research should be done on the associations with intermediary determinants and socioeconomic and political context. PMID:22944744

  15. Professional Standards for Visual Arts Educators

    Science.gov (United States)

    National Art Education Association, 2009

    2009-01-01

    The National Art Education Association (NAEA) is committed to ensuring that all students have access to a high quality, certified visual arts educator in every K-12 public school across the United States, recognizing that effective arts instruction is a core component of 21st-century education. "Professional Standards for Visual Arts…

  16. Development of Robust Behaviour Recognition for an at-Home Biomonitoring Robot with Assistance of Subject Localization and Enhanced Visual Tracking

    Science.gov (United States)

    Imamoglu, Nevrez; Dorronzoro, Enrique; Wei, Zhixuan; Shi, Huangjun; González, José; Gu, Dongyun; Yu, Wenwei

    2014-01-01

    Our research is focused on the development of an at-home health care biomonitoring mobile robot for the people in demand. Main task of the robot is to detect and track a designated subject while recognizing his/her activity for analysis and to provide warning in an emergency. In order to push forward the system towards its real application, in this study, we tested the robustness of the robot system with several major environment changes, control parameter changes, and subject variation. First, an improved color tracker was analyzed to find out the limitations and constraints of the robot visual tracking considering the suitable illumination values and tracking distance intervals. Then, regarding subject safety and continuous robot based subject tracking, various control parameters were tested on different layouts in a room. Finally, the main objective of the system is to find out walking activities for different patterns for further analysis. Therefore, we proposed a fast, simple, and person specific new activity recognition model by making full use of localization information, which is robust to partial occlusion. The proposed activity recognition algorithm was tested on different walking patterns with different subjects, and the results showed high recognition accuracy. PMID:25587560

  17. Development of Robust Behaviour Recognition for an at-Home Biomonitoring Robot with Assistance of Subject Localization and Enhanced Visual Tracking

    Directory of Open Access Journals (Sweden)

    Nevrez Imamoglu

    2014-01-01

    Full Text Available Our research is focused on the development of an at-home health care biomonitoring mobile robot for the people in demand. Main task of the robot is to detect and track a designated subject while recognizing his/her activity for analysis and to provide warning in an emergency. In order to push forward the system towards its real application, in this study, we tested the robustness of the robot system with several major environment changes, control parameter changes, and subject variation. First, an improved color tracker was analyzed to find out the limitations and constraints of the robot visual tracking considering the suitable illumination values and tracking distance intervals. Then, regarding subject safety and continuous robot based subject tracking, various control parameters were tested on different layouts in a room. Finally, the main objective of the system is to find out walking activities for different patterns for further analysis. Therefore, we proposed a fast, simple, and person specific new activity recognition model by making full use of localization information, which is robust to partial occlusion. The proposed activity recognition algorithm was tested on different walking patterns with different subjects, and the results showed high recognition accuracy.

  18. Development of robust behaviour recognition for an at-home biomonitoring robot with assistance of subject localization and enhanced visual tracking.

    Science.gov (United States)

    Imamoglu, Nevrez; Dorronzoro, Enrique; Wei, Zhixuan; Shi, Huangjun; Sekine, Masashi; González, José; Gu, Dongyun; Chen, Weidong; Yu, Wenwei

    2014-01-01

    Our research is focused on the development of an at-home health care biomonitoring mobile robot for the people in demand. Main task of the robot is to detect and track a designated subject while recognizing his/her activity for analysis and to provide warning in an emergency. In order to push forward the system towards its real application, in this study, we tested the robustness of the robot system with several major environment changes, control parameter changes, and subject variation. First, an improved color tracker was analyzed to find out the limitations and constraints of the robot visual tracking considering the suitable illumination values and tracking distance intervals. Then, regarding subject safety and continuous robot based subject tracking, various control parameters were tested on different layouts in a room. Finally, the main objective of the system is to find out walking activities for different patterns for further analysis. Therefore, we proposed a fast, simple, and person specific new activity recognition model by making full use of localization information, which is robust to partial occlusion. The proposed activity recognition algorithm was tested on different walking patterns with different subjects, and the results showed high recognition accuracy.

  19. The Role of Visual Cues in Microgravity Spatial Orientation

    Science.gov (United States)

    Oman, Charles M.; Howard, Ian P.; Smith, Theodore; Beall, Andrew C.; Natapoff, Alan; Zacher, James E.; Jenkin, Heather L.

    2003-01-01

    In weightlessness, astronauts must rely on vision to remain spatially oriented. Although gravitational down cues are missing, most astronauts maintain a subjective vertical -a subjective sense of which way is up. This is evidenced by anecdotal reports of crewmembers feeling upside down (inversion illusions) or feeling that a floor has become a ceiling and vice versa (visual reorientation illusions). Instability in the subjective vertical direction can trigger disorientation and space motion sickness. On Neurolab, a virtual environment display system was used to conduct five interrelated experiments, which quantified: (a) how the direction of each person's subjective vertical depends on the orientation of the surrounding visual environment, (b) whether rolling the virtual visual environment produces stronger illusions of circular self-motion (circular vection) and more visual reorientation illusions than on Earth, (c) whether a virtual scene moving past the subject produces a stronger linear self-motion illusion (linear vection), and (d) whether deliberate manipulation of the subjective vertical changes a crewmember's interpretation of shading or the ability to recognize objects. None of the crew's subjective vertical indications became more independent of environmental cues in weightlessness. Three who were either strongly dependent on or independent of stationary visual cues in preflight tests remained so inflight. One other became more visually dependent inflight, but recovered postflight. Susceptibility to illusions of circular self-motion increased in flight. The time to the onset of linear self-motion illusions decreased and the illusion magnitude significantly increased for most subjects while free floating in weightlessness. These decreased toward one-G levels when the subject 'stood up' in weightlessness by wearing constant force springs. For several subjects, changing the relative direction of the subjective vertical in weightlessness-either by body

  20. Visualization of Multi-mission Astronomical Data with ESASky

    Science.gov (United States)

    Baines, Deborah; Giordano, Fabrizio; Racero, Elena; Salgado, Jesús; López Martí, Belén; Merín, Bruno; Sarmiento, María-Henar; Gutiérrez, Raúl; Ortiz de Landaluce, Iñaki; León, Ignacio; de Teodoro, Pilar; González, Juan; Nieto, Sara; Segovia, Juan Carlos; Pollock, Andy; Rosa, Michael; Arviset, Christophe; Lennon, Daniel; O'Mullane, William; de Marchi, Guido

    2017-02-01

    ESASky is a science-driven discovery portal to explore the multi-wavelength sky and visualize and access multiple astronomical archive holdings. The tool is a web application that requires no prior knowledge of any of the missions involved and gives users world-wide simplified access to the highest-level science data products from multiple astronomical space-based astronomy missions plus a number of ESA source catalogs. The first public release of ESASky features interfaces for the visualization of the sky in multiple wavelengths, the visualization of query results summaries, and the visualization of observations and catalog sources for single and multiple targets. This paper describes these features within ESASky, developed to address use cases from the scientific community. The decisions regarding the visualization of large amounts of data and the technologies used were made to maximize the responsiveness of the application and to keep the tool as useful and intuitive as possible.

  1. Conditioned sounds enhance visual processing.

    Directory of Open Access Journals (Sweden)

    Fabrizio Leo

    Full Text Available This psychophysics study investigated whether prior auditory conditioning influences how a sound interacts with visual perception. In the conditioning phase, subjects were presented with three pure tones ( =  conditioned stimuli, CS that were paired with positive, negative or neutral unconditioned stimuli. As unconditioned reinforcers we employed pictures (highly pleasant, unpleasant and neutral or monetary outcomes (+50 euro cents, -50 cents, 0 cents. In the subsequent visual selective attention paradigm, subjects were presented with near-threshold Gabors displayed in their left or right hemifield. Critically, the Gabors were presented in synchrony with one of the conditioned sounds. Subjects discriminated whether the Gabors were presented in their left or right hemifields. Participants determined the location more accurately when the Gabors were presented in synchrony with positive relative to neutral sounds irrespective of reinforcer type. Thus, previously rewarded relative to neutral sounds increased the bottom-up salience of the visual Gabors. Our results are the first demonstration that prior auditory conditioning is a potent mechanism to modulate the effect of sounds on visual perception.

  2. Cortical activation during Braille reading is influenced by early visual experience in subjects with severe visual disability: a correlational fMRI study.

    Science.gov (United States)

    Melzer, P; Morgan, V L; Pickens, D R; Price, R R; Wall, R S; Ebner, F F

    2001-11-01

    Functional magnetic resonance imaging was performed on blind adults resting and reading Braille. The strongest activation was found in primary somatic sensory/motor cortex on both cortical hemispheres. Additional foci of activation were situated in the parietal, temporal, and occipital lobes where visual information is processed in sighted persons. The regions were differentiated most in the correlation of their time courses of activation with resting and reading. Differences in magnitude and expanse of activation were substantially less significant. Among the traditionally visual areas, the strength of correlation was greatest in posterior parietal cortex and moderate in occipitotemporal, lateral occipital, and primary visual cortex. It was low in secondary visual cortex as well as in dorsal and ventral inferior temporal cortex and posterior middle temporal cortex. Visual experience increased the strength of correlation in all regions except dorsal inferior temporal and posterior parietal cortex. The greatest statistically significant increase, i.e., approximately 30%, was in ventral inferior temporal and posterior middle temporal cortex. In these regions, words are analyzed semantically, which may be facilitated by visual experience. In contrast, visual experience resulted in a slight, insignificant diminution of the strength of correlation in dorsal inferior temporal cortex where language is analyzed phonetically. These findings affirm that posterior temporal regions are engaged in the processing of written language. Moreover, they suggest that this function is modified by early visual experience. Furthermore, visual experience significantly strengthened the correlation of activation and Braille reading in occipital regions traditionally involved in the processing of visual features and object recognition suggesting a role for visual imagery. Copyright 2001 Wiley-Liss, Inc.

  3. WetDATA Hub: Democratizing Access to Water Data to Accelerate Innovation through Data Visualization, Predictive Analytics and Artificial Intelligence Applications

    Science.gov (United States)

    Sarni, W.

    2017-12-01

    Water scarcity and poor quality impacts economic development, business growth, and social well-being. Water has become, in our generation, the foremost critical local, regional, and global issue of our time. Despite these needs, there is no water hub or water technology accelerator solely dedicated to water data and tools. There is a need by the public and private sectors for vastly improved data management and visualization tools. This is the WetDATA opportunity - to develop a water data tech hub dedicated to water data acquisition, analytics, and visualization tools for informed policy and business decisions. WetDATA's tools will help incubate disruptive water data technologies and accelerate adoption of current water data solutions. WetDATA is a Colorado-based (501c3), global hub for water data analytics and technology innovation. WetDATA's vision is to be a global leader in water information, data technology innovation and collaborate with other US and global water technology hubs. ROADMAP * Portal (www.wetdata.org) to provide stakeholders with tools/resources to understand related water risks. * The initial activities will provide education, awareness and tools to stakeholders to support the implementation of the Colorado State Water Plan. * Leverage the Western States Water Council Water Data Exchange database. * Development of visualization, predictive analytics and AI tools to engage with stakeholders and provide actionable data and information. TOOLS Education: Provide information on water issues and risks at the local, state, national and global scale. Visualizations: Development of data analytics and visualization tools based upon the 2030 Water Resources Group methodology to support the implementation of the Colorado State Water Plan. Predictive Analytics: Accessing publically available water databases and using machine learning to develop water availability forecasting tools, and time lapse images to support city / urban planning.

  4. Primary visual cortex volume and total neuron number are reduced in schizophrenia

    DEFF Research Database (Denmark)

    Dorph-Petersen, Karl-Anton; Pierri, Joseph H.; Wu, Qiang

    2007-01-01

    A number of studies that assessed the visual system in subjects with schizophrenia found impairments in early visual processing. Furthermore, functional imaging studies suggested changes in primary visual cortex activity in subjects with schizophrenia. Interestingly, postmortem studies of subject...

  5. Visual Working Memory Storage Recruits Sensory Processing Areas

    NARCIS (Netherlands)

    Gayet, Surya; Paffen, Chris L E; Van der Stigchel, Stefan

    Human visual processing is subject to a dynamic influx of visual information. Visual working memory (VWM) allows for maintaining relevant visual information available for subsequent behavior. According to the dominating view, VWM recruits sensory processing areas to maintain this visual information

  6. Visual working memory storage recruits sensory processing areas

    NARCIS (Netherlands)

    Gayet, S.; Paffen, C.L.E.; Stigchel, S. van der

    2018-01-01

    Human visual processing is subject to a dynamic influx of visual information. Visual working memory (VWM) allows for maintaining relevant visual information available for subsequent behavior. According to the dominating view, VWM recruits sensory processing areas to maintain this visual information

  7. Public Computer Assisted Learning Facilities for Children with Visual Impairment: Universal Design for Inclusive Learning

    Science.gov (United States)

    Siu, Kin Wai Michael; Lam, Mei Seung

    2012-01-01

    Although computer assisted learning (CAL) is becoming increasingly popular, people with visual impairment face greater difficulty in accessing computer-assisted learning facilities. This is primarily because most of the current CAL facilities are not visually impaired friendly. People with visual impairment also do not normally have access to…

  8. Gestalt Theory in Visual Screen Design — A New Look at an old subject

    OpenAIRE

    Chang, D.; Dooley, L.; Tuovinen, J. E

    2002-01-01

    Although often presented as a single basis for educational visual screen design, Gestalt theory is not a single small set of visual principles uniformly applied by all designers. In fact, it appears that instructional visual design literature often deals with only a small set of Gestalt laws. In this project Gestalt literature was consulted to distil the most relevant Gestalt laws for educational visual screen design. Eleven laws were identified. They deal with balance/symmetry, continuation,...

  9. Similarity relations in visual search predict rapid visual categorization

    Science.gov (United States)

    Mohan, Krithika; Arun, S. P.

    2012-01-01

    How do we perform rapid visual categorization?It is widely thought that categorization involves evaluating the similarity of an object to other category items, but the underlying features and similarity relations remain unknown. Here, we hypothesized that categorization performance is based on perceived similarity relations between items within and outside the category. To this end, we measured the categorization performance of human subjects on three diverse visual categories (animals, vehicles, and tools) and across three hierarchical levels (superordinate, basic, and subordinate levels among animals). For the same subjects, we measured their perceived pair-wise similarities between objects using a visual search task. Regardless of category and hierarchical level, we found that the time taken to categorize an object could be predicted using its similarity to members within and outside its category. We were able to account for several classic categorization phenomena, such as (a) the longer times required to reject category membership; (b) the longer times to categorize atypical objects; and (c) differences in performance across tasks and across hierarchical levels. These categorization times were also accounted for by a model that extracts coarse structure from an image. The striking agreement observed between categorization and visual search suggests that these two disparate tasks depend on a shared coarse object representation. PMID:23092947

  10. Accessibility of Sporting Activities for Mainstreamed Students with ...

    African Journals Online (AJOL)

    This study investigated the accessibility of sporting activities for mainstreamed students with visual impairment in Bulawayo Metropolitan Province. The purpose of the study was to identify preparedness of institutions and sports clubs in catering for sporting activities for persons with visual impairment. The study also sought ...

  11. Subjective vs. objective evaluation of gallbladder opacification during oral cholecystography in comparative clinical trials: implications for studies involving visual assessment

    International Nuclear Information System (INIS)

    Fon, G.T.; Hunter, T.B.; Berk, R.N.; Patton, D.D.; Capp, M.P.

    1982-01-01

    Radiographs and CT images taken during oral cholecystography in dogs were interpreted in an independent, blind fashion by three radiologists on two occasions and visual assessment of gallbladder density compared to the actual CT values. While there was significant intra- and inter-observer variation, the mean scores for the observers' interpretations of both radiographs and prints correlated well with the actual CT values (p > 0.05). In five out of six comparisons between first and second readings, the observers gave a lower score on the second reading. The considerable variation reflects the problems inherent in subjective evaluation of agents that produce small but measurable differences in radiographic density. Studies involving such subjective data have to be carefully designed in order to obtain meaningful results

  12. Textual information access statistical models

    CERN Document Server

    Gaussier, Eric

    2013-01-01

    This book presents statistical models that have recently been developed within several research communities to access information contained in text collections. The problems considered are linked to applications aiming at facilitating information access:- information extraction and retrieval;- text classification and clustering;- opinion mining;- comprehension aids (automatic summarization, machine translation, visualization).In order to give the reader as complete a description as possible, the focus is placed on the probability models used in the applications

  13. Deploying web-based visual exploration tools on the grid

    Energy Technology Data Exchange (ETDEWEB)

    Jankun-Kelly, T.J.; Kreylos, Oliver; Shalf, John; Ma, Kwan-Liu; Hamann, Bernd; Joy, Kenneth; Bethel, E. Wes

    2002-02-01

    We discuss a web-based portal for the exploration, encapsulation, and dissemination of visualization results over the Grid. This portal integrates three components: an interface client for structured visualization exploration, a visualization web application to manage the generation and capture of the visualization results, and a centralized portal application server to access and manage grid resources. We demonstrate the usefulness of the developed system using an example for Adaptive Mesh Refinement (AMR) data visualization.

  14. Visual Climate Knowledge Discovery within a Grid Environment

    Science.gov (United States)

    Heitzler, Magnus; Kiertscher, Simon; Lang, Ulrich; Nocke, Thomas; Wahnes, Jens; Winkelmann, Volker

    2013-04-01

    The C3Grid-INAD project aims to provide a common grid infrastructure for the climate science community to improve access to climate related data and domain workflows via the Internet. To make sense of the heterogeneous, often large-sized or even dynamically generated and modified files originating from C3Grid, a highly flexible and user-friendly analysis software is needed to run on different high-performance computing nodes within the grid environment, when requested by a user. Because visual analysis tools directly address human visual perception and therefore are being considered to be highly intuitive, two distinct visualization workflows have been integrated in C3Grid-INAD, targeting different application backgrounds. First, a GrADS-based workflow enables the ad-hoc visualization of selected datasets in respect to data source, temporal and spatial extent, as well as variables of interest. Being low in resource demands, this workflow allows for users to gain fast insights through basic spatial visualization. For more advanced visual analysis purposes, a second workflow enables the user to start a visualization session via Virtual Network Computing (VNC) and VirtualGL to access high-performance computing nodes on which a wide variety of different visual analysis tools are provided. These are made available using the easy-to-use software system SimEnvVis. Considering metadata as well as user preferences and analysis goals, SimEnvVis evaluates the attached tools and launches the selected visual analysis tool by providing a dynamically parameterized template. This approach facilitates the selection of the most suitable tools, and at the same time eases the process of familiarization with them. Because of a higher demand for computational resources, SimEnvVis-sessions are restricted to a smaller set of users at a time. This architecture enables climate scientists not only to remotely access, but also to visually analyze highly heterogeneous data originating from C3

  15. Effects of lighting and task parameters on visual acuity and performance

    Energy Technology Data Exchange (ETDEWEB)

    Halonen, L.

    1993-12-31

    Lighting and task parameters and their effects on visual acuity and visual performance are dealt with. The parameters studied are target contrast, target size and subject`s age; and also adaptation luminance, luminance ratio between task and its surrounding and temporal change in luminances are studied. Experiments were carried out to examine the effects of luminance and light spectrum on visual acuity. Young normally sighted, older and low vision people participated in the measurements. In the young and older subject groups the visual acuity remained unchanged at contrasts 0.93 and 0.63 at the luminance range of 15-630 cd/m{sub 2}. The results show that at contrasts 0.03-0.93 young and older subjects` visual acuity remained unchanged in the luminance range of 105-630 cd/m{sub 2}. In the low vision group, the changes in luminances between 25-860 cd/m{sub 2} did not have significant effects on visual acuity measured at high contrast 0.93, at low contrast, slight individual changes were found. The colour temperature of the light sources was altered between 2900-9500 K in the experiment. In the groups of the older, young and low vision subjects the light spectrum did not have significant effects on visual acuity, except for two retinitis pigmentosa subjects. On the basis of the visual acuity experiments, a three dimensional visual acuity model (VA-HUT) has been developed. The model predicts visual acuity as a function of luminance, target contrast and observer age. On the basis of visual acuity experiments visual acuity reserve values have been calculated for different text sizes

  16. Visual cortex in aging and Alzheimer’s disease: Changes in visual field maps and population receptive fields

    Directory of Open Access Journals (Sweden)

    Alyssa A. Brewer

    2014-02-01

    Full Text Available 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.

  17. Characteristics of Open Access Journals in Six Subject Areas

    Science.gov (United States)

    Walters, William H.; Linvill, Anne C.

    2011-01-01

    We examine the characteristics of 663 Open Access (OA) journals in biology, computer science, economics, history, medicine, and psychology, then compare the OA journals with impact factors to comparable subscription journals. There is great variation in the size of OA journals; the largest publishes more than 2,700 articles per year, but half…

  18. High variability of the subjective visual vertical test of vertical perception, in some people with neck pain - Should this be a standard measure of cervical proprioception?

    Science.gov (United States)

    Treleaven, Julia; Takasaki, Hiroshi

    2015-02-01

    Subjective visual vertical (SVV) assesses visual dependence for spacial orientation, via vertical perception testing. Using the computerized rod-and-frame test (CRFT), SVV is thought to be an important measure of cervical proprioception and might be greater in those with whiplash associated disorder (WAD), but to date research findings are inconsistent. The aim of this study was to investigate the most sensitive SVV error measurement to detect group differences between no neck pain control, idiopathic neck pain (INP) and WAD subjects. Cross sectional study. Neck Disability Index (NDI), Dizziness Handicap Inventory short form (DHIsf) and the average constant error (CE), absolute error (AE), root mean square error (RMSE), and variable error (VE) of the SVV were obtained from 142 subjects (48 asymptomatic, 36 INP, 42 WAD). The INP group had significantly (p pain or dizziness handicap. These findings are inconsistent with other measures of cervical proprioception in neck pain and more research is required before the SVV can be considered an important measure and utilized clinically. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  19. Surveillance of Ocular Parameters and Visual Function in Bed Rest Subjects

    Science.gov (United States)

    Cromwell, Ronita L.

    2011-01-01

    Recent visual changes in astronauts have raised concern about ocular health during long duration spaceflight. Seven cases have been documented in astronauts who spent 6 months aboard the International Space Station. These astronauts were male ranging in age from 45 to 55 years old. All astronauts exhibited pre- to post flight refractive changes. Decreased intraocular pressure (IOP) post flight was observed in 3 cases. Fundoscopic exams revealed post flight findings of choroidal folds in 4 cases, optic disc edema in 5 cases and the presence of cotton wool spots in 3 cases. Optical coherence tomography (OCT) confirmed findings of choroidal folds and disc edema, and also documented retinal nerve fiber layer thickening (5 cases). Findings from MRI examinations showed posterior globe flattening (5 cases), optic nerve sheath distention (6 cases) and torturous optic nerves (2 cases). Of the 7 cases, intracranial pressure was measured on 4 astronauts. These 4 showed elevated ICP post-flight that remained elevated for as long as 19 months in one case. While the etiology remains unknown, hypotheses speculate that venous insufficiency or hypertension in the brain caused by cephalad fluid shifts during spaceflight are possible mechanisms for ocular changes seen in astronauts. Head-down tilt bed rest is a spaceflight analog that induces cephalad fluid shifts. This study is designed to provide ocular monitoring of bed rest subjects and determine whether clinically relevant changes are found. Ocular Changes

  20. Longterm visual prognosis in Usher syndrome types 1 and 2.

    Science.gov (United States)

    Sadeghi, André M; Eriksson, Kristina; Kimberling, William J; Sjöström, Anders; Möller, Claes

    2006-08-01

    To estimate the age at diagnosis of retinitis pigmentosa and to determine visual acuity deterioration, visual field impairment and the frequency of cataracts in Usher syndrome types 1 and 2. We carried out a retrospective study of 328 affected subjects with Usher syndrome types 1 and 2. Study subjects were divided into seven different age groups by decade. Data were analysed using descriptive statistics, general linear model anova and survival analysis. Retinitis pigmentosa was diagnosed significantly earlier in subjects with Usher syndrome type 1 than in those with type 2. Visual acuity was significantly more impaired in affected subjects with Usher syndrome type 1 than in those with type 2 from 50 years of age onwards. Survival analysis revealed a significant difference in visual field loss (type 2 subjects tending to be more impaired, while comparison indicated no significant differences between the groups in any of the other visual field categories. Cataract was found to be generally more common in Usher syndrome type 1 than type 2. Progressive loss of visual acuity and visual field begins to be substantial between the second and third decades of life in both Usher types. The rate of degeneration varies between individuals in both groups. The data are useful for the counselling of affected subjects with Usher syndrome types 1 and 2.

  1. Visualizing Cloud Properties and Satellite Imagery: A Tool for Visualization and Information Integration

    Science.gov (United States)

    Chee, T.; Nguyen, L.; Smith, W. L., Jr.; Spangenberg, D.; Palikonda, R.; Bedka, K. M.; Minnis, P.; Thieman, M. M.; Nordeen, M.

    2017-12-01

    Providing public access to research products including cloud macro and microphysical properties and satellite imagery are a key concern for the NASA Langley Research Center Cloud and Radiation Group. This work describes a web based visualization tool and API that allows end users to easily create customized cloud product and satellite imagery, ground site data and satellite ground track information that is generated dynamically. The tool has two uses, one to visualize the dynamically created imagery and the other to provide access to the dynamically generated imagery directly at a later time. Internally, we leverage our practical experience with large, scalable application practices to develop a system that has the largest potential for scalability as well as the ability to be deployed on the cloud to accommodate scalability issues. We build upon NASA Langley Cloud and Radiation Group's experience with making real-time and historical satellite cloud product information, satellite imagery, ground site data and satellite track information accessible and easily searchable. This tool is the culmination of our prior experience with dynamic imagery generation and provides a way to build a "mash-up" of dynamically generated imagery and related kinds of information that are visualized together to add value to disparate but related information. In support of NASA strategic goals, our group aims to make as much scientific knowledge, observations and products available to the citizen science, research and interested communities as well as for automated systems to acquire the same information for data mining or other analytic purposes. This tool and the underlying API's provide a valuable research tool to a wide audience both as a standalone research tool and also as an easily accessed data source that can easily be mined or used with existing tools.

  2. Complex regional pain syndrome (CRPS) or continuous unilateral distal experimental pain stimulation in healthy subjects does not bias visual attention towards one hemifield.

    Science.gov (United States)

    Filippopulos, Filipp M; Grafenstein, Jessica; Straube, Andreas; Eggert, Thomas

    2015-11-01

    In natural life pain automatically draws attention towards the painful body part suggesting that it interacts with different attentional mechanisms such as visual attention. Complex regional pain syndrome (CRPS) patients who typically report on chronic distally located pain of one extremity may suffer from so-called neglect-like symptoms, which have also been linked to attentional mechanisms. The purpose of the study was to further evaluate how continuous pain conditions influence visual attention. Saccade latencies were recorded in two experiments using a common visual attention paradigm whereby orientating saccades to cued or uncued lateral visual targets had to be performed. In the first experiment saccade latencies of healthy subjects were measured under two conditions: one in which continuous experimental pain stimulation was applied to the index finger to imitate a continuous pain situation, and one without pain stimulation. In the second experiment saccade latencies of patients suffering from CRPS were compared to controls. The results showed that neither the continuous experimental pain stimulation during the experiment nor the chronic pain in CRPS led to an unilateral increase of saccade latencies or to a unilateral increase of the cue effect on latency. The results show that unilateral, continuously applied pain stimuli or chronic pain have no or only very limited influence on visual attention. Differently from patients with visual neglect, patients with CRPS did not show strong side asymmetries of saccade latencies or of cue effects on saccade latencies. Thus, neglect-like clinical symptoms of CRPS patients do not involve the allocation of visual attention.

  3. Action-blindsight in healthy subjects after transcranial magnetic stimulation

    DEFF Research Database (Denmark)

    Christensen, Mark Schram; Kristiansen, Lasse; Rowe, James B.

    2008-01-01

    Clinical cases of blindsight have shown that visually guided movements can be accomplished without conscious visual perception. Here, we show that blindsight can be induced in healthy subjects by using transcranial magnetic stimulation over the visual cortex. Transcranial magnetic stimulation...

  4. Complex network inference from P300 signals: Decoding brain state under visual stimulus for able-bodied and disabled subjects

    Science.gov (United States)

    Gao, Zhong-Ke; Cai, Qing; Dong, Na; Zhang, Shan-Shan; Bo, Yun; Zhang, Jie

    2016-10-01

    Distinguishing brain cognitive behavior underlying disabled and able-bodied subjects constitutes a challenging problem of significant importance. Complex network has established itself as a powerful tool for exploring functional brain networks, which sheds light on the inner workings of the human brain. Most existing works in constructing brain network focus on phase-synchronization measures between regional neural activities. In contrast, we propose a novel approach for inferring functional networks from P300 event-related potentials by integrating time and frequency domain information extracted from each channel signal, which we show to be efficient in subsequent pattern recognition. In particular, we construct brain network by regarding each channel signal as a node and determining the edges in terms of correlation of the extracted feature vectors. A six-choice P300 paradigm with six different images is used in testing our new approach, involving one able-bodied subject and three disabled subjects suffering from multiple sclerosis, cerebral palsy, traumatic brain and spinal-cord injury, respectively. We then exploit global efficiency, local efficiency and small-world indices from the derived brain networks to assess the network topological structure associated with different target images. The findings suggest that our method allows identifying brain cognitive behaviors related to visual stimulus between able-bodied and disabled subjects.

  5. Associative visual learning by tethered bees in a controlled visual environment.

    Science.gov (United States)

    Buatois, Alexis; Pichot, Cécile; Schultheiss, Patrick; Sandoz, Jean-Christophe; Lazzari, Claudio R; Chittka, Lars; Avarguès-Weber, Aurore; Giurfa, Martin

    2017-10-10

    Free-flying honeybees exhibit remarkable cognitive capacities but the neural underpinnings of these capacities cannot be studied in flying insects. Conversely, immobilized bees are accessible to neurobiological investigation but display poor visual learning. To overcome this limitation, we aimed at establishing a controlled visual environment in which tethered bees walking on a spherical treadmill learn to discriminate visual stimuli video projected in front of them. Freely flying bees trained to walk into a miniature Y-maze displaying these stimuli in a dark environment learned the visual discrimination efficiently when one of them (CS+) was paired with sucrose and the other with quinine solution (CS-). Adapting this discrimination to the treadmill paradigm with a tethered, walking bee was successful as bees exhibited robust discrimination and preferred the CS+ to the CS- after training. As learning was better in the maze, movement freedom, active vision and behavioral context might be important for visual learning. The nature of the punishment associated with the CS- also affects learning as quinine and distilled water enhanced the proportion of learners. Thus, visual learning is amenable to a controlled environment in which tethered bees learn visual stimuli, a result that is important for future neurobiological studies in virtual reality.

  6. The role of visual representations during the lexical access of spoken words.

    Science.gov (United States)

    Lewis, Gwyneth; Poeppel, David

    2014-07-01

    Do visual representations contribute to spoken word recognition? We examine, using MEG, the effects of sublexical and lexical variables at superior temporal (ST) areas and the posterior middle temporal gyrus (pMTG) compared with that of word imageability at visual cortices. Embodied accounts predict early modulation of visual areas by imageability--concurrently with or prior to modulation of pMTG by lexical variables. Participants responded to speech stimuli varying continuously in imageability during lexical decision with simultaneous MEG recording. We employed the linguistic variables in a new type of correlational time course analysis to assess trial-by-trial activation in occipital, ST, and pMTG regions of interest (ROIs). The linguistic variables modulated the ROIs during different time windows. Critically, visual regions reflected an imageability effect prior to effects of lexicality on pMTG. This surprising effect supports a view on which sensory aspects of a lexical item are not a consequence of lexical activation. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Teach yourself visually Apple Watch

    CERN Document Server

    Hart-Davis, Guy

    2015-01-01

    Master your new smartwatch quickly and easily with this highly visual guide Teach Yourself VISUALLY Apple Watch is a practical, accessible guide to mastering the powerful features and functionality of your new smartwatch. For Apple devotees and new users alike, this easy-to-follow guide features visually rich tutorials and step-by-step instructions that show you how to take advantage of all of the Apple watch's capabilities. You'll learn how to track your health, control household devices, download and install apps, sync your music, sync other Apple devices, and efficiently use the current O

  8. Strange-face illusions during inter-subjective gazing.

    Science.gov (United States)

    Caputo, Giovanni B

    2013-03-01

    In normal observers, gazing at one's own face in the mirror for a few minutes, at a low illumination level, triggers the perception of strange faces, a new visual illusion that has been named 'strange-face in the mirror'. Individuals see huge distortions of their own faces, but they often see monstrous beings, archetypal faces, faces of relatives and deceased, and animals. In the experiment described here, strange-face illusions were perceived when two individuals, in a dimly lit room, gazed at each other in the face. Inter-subjective gazing compared to mirror-gazing produced a higher number of different strange-faces. Inter-subjective strange-face illusions were always dissociative of the subject's self and supported moderate feeling of their reality, indicating a temporary lost of self-agency. Unconscious synchronization of event-related responses to illusions was found between members in some pairs. Synchrony of illusions may indicate that unconscious response-coordination is caused by the illusion-conjunction of crossed dissociative strange-faces, which are perceived as projections into each other's visual face of reciprocal embodied representations within the pair. Inter-subjective strange-face illusions may be explained by the subject's embodied representations (somaesthetic, kinaesthetic and motor facial pattern) and the other's visual face binding. Unconscious facial mimicry may promote inter-subjective illusion-conjunction, then unconscious joint-action and response-coordination. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Auditory attention activates peripheral visual cortex.

    Directory of Open Access Journals (Sweden)

    Anthony D Cate

    Full Text Available BACKGROUND: Recent neuroimaging studies have revealed that putatively unimodal regions of visual cortex can be activated during auditory tasks in sighted as well as in blind subjects. However, the task determinants and functional significance of auditory occipital activations (AOAs remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: We examined AOAs in an intermodal selective attention task to distinguish whether they were stimulus-bound or recruited by higher-level cognitive operations associated with auditory attention. Cortical surface mapping showed that auditory occipital activations were localized to retinotopic visual cortex subserving the far peripheral visual field. AOAs depended strictly on the sustained engagement of auditory attention and were enhanced in more difficult listening conditions. In contrast, unattended sounds produced no AOAs regardless of their intensity, spatial location, or frequency. CONCLUSIONS/SIGNIFICANCE: Auditory attention, but not passive exposure to sounds, routinely activated peripheral regions of visual cortex when subjects attended to sound sources outside the visual field. Functional connections between auditory cortex and visual cortex subserving the peripheral visual field appear to underlie the generation of AOAs, which may reflect the priming of visual regions to process soon-to-appear objects associated with unseen sound sources.

  10. Subjective visual vertical before and after treatment of a BPPV episode.

    Science.gov (United States)

    Faralli, Mario; Manzari, Leonardo; Panichi, Roberto; Botti, Fabio; Ricci, Giampietro; Longari, Fabrizio; Pettorossi, Vito Enrico

    2011-06-01

    The study analyses the behavior of subjective visual vertical (SVV) in benign paroxysmal positional vertigo (BPPV) before and after treatment, and offers a clinical-pathogenic interpretation. We studied 30 consecutive patients with BPPV of the posterior semicircular canal treated with the Epley repositioning maneuver. SVV was determined at three different stages: at the time of diagnosis (1st test), after the repositioning maneuver (2nd test), and then 7 days after the resolution of the clinical picture (3rd test). The main study parameter was represented by the mean of 6 consecutive measurements (SVV(0)) for each patient. SVV was also examined in 20 healthy subjects, who represented the control group. The comparison between mean values and standard deviations showed a statistical significance of p<0.05. During the first test, the degree of deviation of SVV was significantly higher in the patient group than in the control group. Tilting towards the affected side was observed in all cases. The 2nd test showed an inversion in the orientation of SVV in 16 patients, and as a result of the Epley maneuver there was a statistically significant variation in SVV(0) values in 20 patients with respect to the previous test (2nd test vs. 1st test). This involved 87% (23 patients) of those who then had a negative Dix-Hallpike test, and none of the ones in whom paroxysmal positional nystagmus persisted. Lastly, no differences emerged in the behavior of the patient group vs. the control group during the third test. SVV is often altered during active BPPV. The degree of otolithic dysfunction is never high and, in all cases, it is brief in duration. Tilting towards the dysfunctional side is essentially a constant in untreated BPPV. This could be due to a substantial loss of otoconia, with a decrease in the density and specific weight of the macula, and thus hypofunction of the receptor. The observation of a significant variation in SVV after therapeutic maneuvers has a favorable

  11. Color-Space-Based Visual-MIMO for V2X Communication.

    Science.gov (United States)

    Kim, Jai-Eun; Kim, Ji-Won; Park, Youngil; Kim, Ki-Doo

    2016-04-23

    In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol), and multiplexing-diversity mode transitions. In addition, in the V2X scenario of multiple access, we may achieve the simultaneous multiple access communication without node interferences by dividing the communication area using image processing. Finally, through numerical simulation, we show the superior SER performance of the visual-MIMO scheme compared with LED-PD communication and show the numerical result of the GCM based visual-MIMO channel capacity versus distance.

  12. Interactive SIGHT: textual access to simple bar charts

    Science.gov (United States)

    Demir, Seniz; Oliver, David; Schwartz, Edward; Elzer, Stephanie; Carberry, Sandra; Mccoy, Kathleen F.; Chester, Daniel

    2010-12-01

    Information graphics, such as bar charts and line graphs, are an important component of many articles from popular media. The majority of such graphics have an intention (a high-level message) to communicate to the graph viewer. Since the intended message of a graphic is often not repeated in the accompanying text, graphics together with the textual segments contribute to the overall purpose of an article and cannot be ignored. Unfortunately, these visual displays are provided in a format which is not readily accessible to everyone. For example, individuals with sight impairments who use screen readers to listen to documents have limited access to the graphics. This article presents a new accessibility tool, the Interactive SIGHT (Summarizing Information GrapHics Textually) system, that is intended to enable visually impaired users to access the knowledge that one would gain from viewing information graphics found on the web. The current system, which is implemented as a browser extension that works on simple bar charts, can be invoked by a user via a keystroke combination while navigating the web. Once launched, Interactive SIGHT first provides a brief summary that conveys the underlying intention of a bar chart along with the chart's most significant and salient features, and then produces history-aware follow-up responses to provide further information about the chart upon request from the user. We present two user studies that were conducted with sighted and visually impaired users to determine how effective the initial summary and follow-up responses are in conveying the informational content of bar charts, and to evaluate how easy it is to use the system interface. The evaluation results are promising and indicate that the system responses are well-structured and enable visually impaired users to answer key questions about bar charts in an easy-to-use manner. Post-experimental interviews revealed that visually impaired participants were very satisfied with

  13. Custom Formula-Based Visualizations for Savvy Designers"

    DEFF Research Database (Denmark)

    Kuhail, Mohammad Amin

    and expressive. For instance, chart tools are easy to use, but support only predefined visualizations, while visualization tools support custom visualizations, but require program-like specifications. This thesis presents Uvis, a visualization system that targets savvy designers. With Uvis, designers drag......Despite their usefulness in many domains (e.g. healthcare, finance, etc.), custom visualizations remain tedious and hard to implement. It would be advantageous if savvy designers (designers with end-user development skills and much domain knowledge) could refine visualizations to their needs....... For instance, it would save time and money if a clinician familiar with spreadsheet formulas could refine a visualization (e.g. the lifelines) rather than hiring a programmer. Existing approaches to visualization are one of the two: accessible to savvy designers but limited in customizability, or inaccessible...

  14. Visual impairment and amblyopia in Malaysian pre-school children - The SEGPAEDS study.

    Science.gov (United States)

    Chew, F L M; Thavaratnam, L K; Shukor, I N C; Ramasamy, S; Rahmat, J; Reidpath, D D; Allotey, P; Alagaratnam, J

    2018-02-01

    Little is known regarding the extent of visual impairment amongst pre-school children in Malaysia. To determine the prevalence of visual impairment and amblyopia in Malaysian preschool children. A cross-sectional, population-based study was conducted on children aged four to six years from 51 participating kindergartens in the district of Segamat, Johor, Malaysia from 20 March 2016 to 6 April 2016. All subjects had initial eye screening consisting of LogMar visual acuity, orthoptics examination and Spot vision screener assessment. Subjects who failed the initial eye screening were invited for a formal eye assessment consisting of cycloplegic refraction and a comprehensive ocular examination. Definitions of visual impairment and amblyopia were based on the Multi-Ethnic Pediatric Eye Disease Study criteria. A total of 1287 children were recruited. Mean subject age was 5.03 (SD:0.77) and males represented 52.3% of subjects. Subjects by ethnicity were Malay (54.8%), Chinese (27.7%), Indian (15.6%) and Orang Asli (1.9%). Formal eye assessment was required for 221 subjects and 88.8% required ophthalmic intervention. Refractive error, representing 95.4% of diagnosed ocular disorders, comprised of astigmatism (84%), myopia (9%) and hypermetropia (6.9%). With-the-rule astigmatism was present in 93.4% of the subjects with astigmatism. Visual impairment was present in 12.5% of our subjects, with 61% having bilateral visual impairment. Of the subjects with visual impairment, 59.1% had moderate visual impairment. The prevalence of amblyopia was 7.53%, and 66% of the amblyopic subjects had bilateral amblyopia. Our study highlights an urgent need for initiation of preschool vision screening in Malaysia.

  15. METHOD AND ABSTRACT MODEL FOR CONTROL AND ACCESS RIGHTS BY REQUESTS REDIRECTION

    Directory of Open Access Journals (Sweden)

    K. A. Shcheglov

    2015-11-01

    Full Text Available We have researched implementation problems of control and access rights of subjects to objects in modern computer systems. We have suggested access control method based on objects access requests redirection. The method possesses a distinctive feature as compared to discretional access control. In case when a subject needs to deny writing (object modification, it is not denied but redirected (access rights are not changed, but operation is performed with another object. This gives the possibility to implement access policies to system objects without breaking the system and applications operability, and share correctly access objects between subjects. This important property of suggested access control method enables to solve fundamentally new system objects securing problems like system resources virtualization aimed to protect system objects from users’ and applications attacks. We have created an abstract model, and it shows that this method (access control from subjects to objects based on requests redirection can be used as self-sufficient access control method, implementing any access control policy (from subjects to objects, thus being an alternative to discretional access control method.

  16. Performance of Single-Use FlexorVue vs Reusable BoaVision Ureteroscope for Visualization of Calices and Stone Extraction in an Artificial Kidney Model.

    Science.gov (United States)

    Schlager, Daniel; Hein, Simon; Obaid, Moaaz Abdulghani; Wilhelm, Konrad; Miernik, Arkadiusz; Schoenthaler, Martin

    2017-11-01

    To evaluate and compare Flexor ® Vue™, a semidisposable endoscopic deflection system with disposable ureteral sheath and reusable visualization source, and a nondisposable fiber optic ureteroscope in a standard in vitro setting. FlexorVue and a reusable fiber optic flexible ureteroscope were each tested in an artificial kidney model. The experimental setup included the visualization of colored pearls and the extraction of calculi with two different extraction devices (NCircle ® and NGage ® ). The procedures were performed by six experienced surgeons. Visualization time, access to calices, successful stone retraction, and time required were recorded. In addition, the surgeons' workload and subjective performance were determined according to the National Aeronautics and Space Administration-task load index (NASA-TLX). We referred to the Likert scale to assess maneuverability, handling, and image quality. Nearly all calices (99%) were correctly identified using the reusable scope, indicating full kidney access, whereas 74% of the calices were visualized using FlexorVue, of which 81% were correctly identified. Access to the lower poles of the kidney model was significantly less likely with the disposable device, and time to completion was significantly longer (755 s vs 153 s, p NASA-TLX scores were significantly higher using FlexorVue. The conventional reusable device also demonstrated superior maneuverability, handling, and image quality. FlexorVue offers a semidisposable deflecting endoscopic system allowing basic ureteroscopic and cystoscopic procedures. For its use as an addition or replacement for current reusable scopes, it requires substantial technical improvements.

  17. Expansion of the ipsilateral visual corticotectal projection in hamsters subjected to partial lesions of the visual cortex during infancy: anatomical experiments

    International Nuclear Information System (INIS)

    Rhoades, R.W.

    1981-01-01

    Electrophysiological methods were employed to determine whether or not partial visual cortical lesions in neonatal (7--11-day) hamster produced large scotomas in the cortical visual representation. In cases where such scotomas were present electrophoretic deposits of radioactive amino acids in the visually responsive ''cortical remnant'' of the damaged hemisphere resulted in labelling throughout the lower portion of the stratum griseum superficiale and the stratum opticum of the ipsilateral superior colliculus. No differential labeling of the part of the colliculus which was topographically matched with the remaining visual representation in the cortical remnant was observed. In normal hamsters relatively localized, visual cortical deposits of radioactive amino acids resulted in superficial layer labeling only in portions of the colliculus which corresponded to the locus of the cortical deposit. In a similar fashion, small lesions at physiologically defined loci in the cortical remnant produced degeneration throughout most of the superficial tectal laminae, but a more restricted ''focus'' of denser degeneration was also visible in these cases. The position of this focus in the colliculus for a given cortical lesion varied with the nature of the visual map in the cortical remnant. In several additional neonatally brain-damaged hamsters large lesions of the visual cortex in the intact hemisphere were combined with radioactive amino acid deposits in the cortical remnant to determine whether or not axons from the crossed corticocollicular pathway previously demonstrated in such hamsters were intermingled with fibers from the ipsilateral corticotectal projection. In alternate sections processed for autoradiography or by the Fink-Heimer ('67) method autoradiographic label and degeneration argyrophilia were both observed in the medical part of the colliculus ipsilateral to the neonatal cortical lesion

  18. The Impact of Cataract Surgery on Subjective Visual Functions and ...

    African Journals Online (AJOL)

    Purpose: To determine the impact of cataract surgery on visual functions (VFs) and quality of life (QoL) in patients with cataract at the National Eye Center, Kaduna. Methods: VFs and QoL questionnaires were administered to the patients preoperatively and 6 weeks postoperatively. Correlation was assessed among ...

  19. Storage and binding of object features in visual working memory

    OpenAIRE

    Bays, Paul M; Wu, Emma Y; Husain, Masud

    2010-01-01

    An influential conception of visual working memory is of a small number of discrete memory “slots”, each storing an integrated representation of a single visual object, including all its component features. When a scene contains more objects than there are slots, visual attention controls which objects gain access to memory.

  20. EDA-BASED ESTIMATION OF VISUAL ATTENTION BY OBSERVATION OF EYE BLINK FREQUENCY

    OpenAIRE

    Sakai, Tsugunosuke; Tamaki, Haruya; Ota, Yosuke; Egusa, Ryohei; Inagaki, Shigenori; Kusunoki, Fusako; Sugimoto, Masanori; Mizoguchi, Hiroshi

    2017-01-01

    This paper describes the relationship between visual attention and eye blink frequency. In an experiment, we prompted the activation of a subject's visual attention and examined the influence of visual attention (as measured using electrodermal activity (EDA), which is meaningfully correlated with visual attention) on the subject's eye blink frequency. Experimental results show that engagement of visual attention decreased eye blink frequency and that when visual attention was not activated, ...

  1. Visual Literacy Practices in Higher Education

    OpenAIRE

    Schellenberg, Julia

    2015-01-01

    Joint Master Degree in Digital Library Learning (DILL) In our media-driven age visuals are increasingly frequent and prominently present in society and their importance and influence across academic disciplines is growing. This makes it essential to enable learners to become visually literate and justifies the need for teaching visual literacy competencies. Yet, there has been little research on visual literacy practices undertaken across academic subjects and institutions in h...

  2. Visualization-by-Sketching: An Artist's Interface for Creating Multivariate Time-Varying Data Visualizations.

    Science.gov (United States)

    Schroeder, David; Keefe, Daniel F

    2016-01-01

    We present Visualization-by-Sketching, a direct-manipulation user interface for designing new data visualizations. The goals are twofold: First, make the process of creating real, animated, data-driven visualizations of complex information more accessible to artists, graphic designers, and other visual experts with traditional, non-technical training. Second, support and enhance the role of human creativity in visualization design, enabling visual experimentation and workflows similar to what is possible with traditional artistic media. The approach is to conceive of visualization design as a combination of processes that are already closely linked with visual creativity: sketching, digital painting, image editing, and reacting to exemplars. Rather than studying and tweaking low-level algorithms and their parameters, designers create new visualizations by painting directly on top of a digital data canvas, sketching data glyphs, and arranging and blending together multiple layers of animated 2D graphics. This requires new algorithms and techniques to interpret painterly user input relative to data "under" the canvas, balance artistic freedom with the need to produce accurate data visualizations, and interactively explore large (e.g., terabyte-sized) multivariate datasets. Results demonstrate a variety of multivariate data visualization techniques can be rapidly recreated using the interface. More importantly, results and feedback from artists support the potential for interfaces in this style to attract new, creative users to the challenging task of designing more effective data visualizations and to help these users stay "in the creative zone" as they work.

  3. Endogenous visuospatial attention increases visual awareness independent of visual discrimination sensitivity.

    Science.gov (United States)

    Vernet, Marine; Japee, Shruti; Lokey, Savannah; Ahmed, Sara; Zachariou, Valentinos; Ungerleider, Leslie G

    2017-08-12

    Visuospatial attention often improves task performance by increasing signal gain at attended locations and decreasing noise at unattended locations. Attention is also believed to be the mechanism that allows information to enter awareness. In this experiment, we assessed whether orienting endogenous visuospatial attention with cues differentially affects visual discrimination sensitivity (an objective task performance) and visual awareness (the subjective feeling of perceiving) during the same discrimination task. Gabor patch targets were presented laterally, either at low contrast (contrast stimuli) or at high contrast embedded in noise (noise stimuli). Participants reported their orientation either in a 3-alternative choice task (clockwise, counterclockwise, unknown) that allowed for both objective and subjective reports, or in a 2-alternative choice task (clockwise, counterclockwise) that provided a control for objective reports. Signal detection theory models were fit to the experimental data: estimated perceptual sensitivity reflected objective performance; decision criteria, or subjective biases, were a proxy for visual awareness. Attention increased sensitivity (i.e., improved objective performance) for the contrast, but not for the noise stimuli. Indeed, with the latter, attention did not further enhance the already high target signal or reduce the already low uncertainty on its position. Interestingly, for both contrast and noise stimuli, attention resulted in more liberal criteria, i.e., awareness increased. The noise condition is thus an experimental configuration where people think they see the targets they attend to better, even if they do not. This could be explained by an internal representation of their attentional state, which influences awareness independent of objective visual signals. Copyright © 2017. Published by Elsevier Ltd.

  4. Accessibility

    DEFF Research Database (Denmark)

    Brooks, Anthony Lewis

    2017-01-01

    This contribution is timely as it addresses accessibility in regards system hardware and software aligned with introduction of the Twenty-First Century Communications and Video Accessibility Act (CVAA) and adjoined game industry waiver that comes into force January 2017. This is an act created...... by the USA Federal Communications Commission (FCC) to increase the access of persons with disabilities to modern communications, and for other purposes. The act impacts advanced communications services and products including text messaging; e-mail; instant messaging; video communications; browsers; game...... platforms; and games software. However, the CVAA has no legal status in the EU. This text succinctly introduces and questions implications, impact, and wider adoption. By presenting the full CVAA and game industry waiver the text targets to motivate discussions and further publications on the subject...

  5. Braille character discrimination in blindfolded human subjects.

    Science.gov (United States)

    Kauffman, Thomas; Théoret, Hugo; Pascual-Leone, Alvaro

    2002-04-16

    Visual deprivation may lead to enhanced performance in other sensory modalities. Whether this is the case in the tactile modality is controversial and may depend upon specific training and experience. We compared the performance of sighted subjects on a Braille character discrimination task to that of normal individuals blindfolded for a period of five days. Some participants in each group (blindfolded and sighted) received intensive Braille training to offset the effects of experience. Blindfolded subjects performed better than sighted subjects in the Braille discrimination task, irrespective of tactile training. For the left index finger, which had not been used in the formal Braille classes, blindfolding had no effect on performance while subjects who underwent tactile training outperformed non-stimulated participants. These results suggest that visual deprivation speeds up Braille learning and may be associated with behaviorally relevant neuroplastic changes.

  6. Negative emotion enhances mnemonic precision and subjective feelings of remembering in visual long-term memory.

    Science.gov (United States)

    Xie, Weizhen; Zhang, Weiwei

    2017-09-01

    Negative emotion sometimes enhances memory (higher accuracy and/or vividness, e.g., flashbulb memories). The present study investigates whether it is the qualitative (precision) or quantitative (the probability of successful retrieval) aspect of memory that drives these effects. In a visual long-term memory task, observers memorized colors (Experiment 1a) or orientations (Experiment 1b) of sequentially presented everyday objects under negative, neutral, or positive emotions induced with International Affective Picture System images. In a subsequent test phase, observers reconstructed objects' colors or orientations using the method of adjustment. We found that mnemonic precision was enhanced under the negative condition relative to the neutral and positive conditions. In contrast, the probability of successful retrieval was comparable across the emotion conditions. Furthermore, the boost in memory precision was associated with elevated subjective feelings of remembering (vividness and confidence) and metacognitive sensitivity in Experiment 2. Altogether, these findings suggest a novel precision-based account for emotional memories. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Los niños con discapacidad visual ante la TV: avances tecnológicos y propuestas Watching TV with visual impaired children

    Directory of Open Access Journals (Sweden)

    Antonio Rodríguez Fuentes

    2008-10-01

    Full Text Available Lamentablemente para las personas con discapacidad visual, la sociedad actual se caracteriza por la exaltación de la imagen y los medios audiovisuales, con fuerte componente visual. A pesar de ello, existen ya medios para ir haciendo posible el acceso íntegro a la cultura visual a las personas con deficiencias, haciéndolas partícipes del universo que representan los medios de comunicación. El diseño accesible o universal permite romper las barreras del sentido visual (para las personas con baja visión o desarrollar sentidos alternativos (para la ceguera. Sin embargo, el autor constata que la realidad, por desgracia, aún no se corresponde con las posibilidades técnicas y tecnológicas que ofrecen los avances técnicos. Unfortunately for visual impaired people, our society is characterised by the exaltation of the image and audiovisual media with a strong visual component. In spite of this there are means already available to make possible a complete access to the visual culture, in particular to mass media. Accessible or universal design allows us sometimes to break the visual sense barriers (for people with impaired vision, and some other times to develop alternative senses (for blind people. Nevertheless, reality does not match the technical and technological possibilities available in present day society.

  8. Biometrics: Accessibility challenge or opportunity?

    Science.gov (United States)

    Blanco-Gonzalo, Ramon; Lunerti, Chiara; Sanchez-Reillo, Raul; Guest, Richard Michael

    2018-01-01

    Biometric recognition is currently implemented in several authentication contexts, most recently in mobile devices where it is expected to complement or even replace traditional authentication modalities such as PIN (Personal Identification Number) or passwords. The assumed convenience characteristics of biometrics are transparency, reliability and ease-of-use, however, the question of whether biometric recognition is as intuitive and straightforward to use is open to debate. Can biometric systems make some tasks easier for people with accessibility concerns? To investigate this question, an accessibility evaluation of a mobile app was conducted where test subjects withdraw money from a fictitious ATM (Automated Teller Machine) scenario. The biometric authentication mechanisms used include face, voice, and fingerprint. Furthermore, we employed traditional modalities of PIN and pattern in order to check if biometric recognition is indeed a real improvement. The trial test subjects within this work were people with real-life accessibility concerns. A group of people without accessibility concerns also participated, providing a baseline performance. Experimental results are presented concerning performance, HCI (Human-Computer Interaction) and accessibility, grouped according to category of accessibility concern. Our results reveal links between individual modalities and user category establishing guidelines for future accessible biometric products.

  9. Biometrics: Accessibility challenge or opportunity?

    Science.gov (United States)

    Lunerti, Chiara; Sanchez-Reillo, Raul; Guest, Richard Michael

    2018-01-01

    Biometric recognition is currently implemented in several authentication contexts, most recently in mobile devices where it is expected to complement or even replace traditional authentication modalities such as PIN (Personal Identification Number) or passwords. The assumed convenience characteristics of biometrics are transparency, reliability and ease-of-use, however, the question of whether biometric recognition is as intuitive and straightforward to use is open to debate. Can biometric systems make some tasks easier for people with accessibility concerns? To investigate this question, an accessibility evaluation of a mobile app was conducted where test subjects withdraw money from a fictitious ATM (Automated Teller Machine) scenario. The biometric authentication mechanisms used include face, voice, and fingerprint. Furthermore, we employed traditional modalities of PIN and pattern in order to check if biometric recognition is indeed a real improvement. The trial test subjects within this work were people with real-life accessibility concerns. A group of people without accessibility concerns also participated, providing a baseline performance. Experimental results are presented concerning performance, HCI (Human-Computer Interaction) and accessibility, grouped according to category of accessibility concern. Our results reveal links between individual modalities and user category establishing guidelines for future accessible biometric products. PMID:29565989

  10. Large Capacity of Conscious Access for Incidental Memories in Natural Scenes.

    Science.gov (United States)

    Kaunitz, Lisandro N; Rowe, Elise G; Tsuchiya, Naotsugu

    2016-09-01

    When searching a crowd, people can detect a target face only by direct fixation and attention. Once the target is found, it is consciously experienced and remembered, but what is the perceptual fate of the fixated nontarget faces? Whereas introspection suggests that one may remember nontargets, previous studies have proposed that almost no memory should be retained. Using a gaze-contingent paradigm, we asked subjects to visually search for a target face within a crowded natural scene and then tested their memory for nontarget faces, as well as their confidence in those memories. Subjects remembered up to seven fixated, nontarget faces with more than 70% accuracy. Memory accuracy was correlated with trial-by-trial confidence ratings, which implies that the memory was consciously maintained and accessed. When the search scene was inverted, no more than three nontarget faces were remembered. These findings imply that incidental memory for faces, such as those recalled by eyewitnesses, is more reliable than is usually assumed. © The Author(s) 2016.

  11. Experimental protocol to assess the tourism vehicles accessibility based on heart rate and access time measurements

    Energy Technology Data Exchange (ETDEWEB)

    Alcala Fazio, E.; Alvarez Fernandez, N.

    2016-07-01

    The objective of the Project is to define an experimental protocol for the accessibility assessment of the transport vehicles, by analysing the evolution of the effort and time variables consumed by a target group –Persons of Reduced Mobility (PMRs). This protocol consisted in tests of accessibility on a sample of 6 passenger cars (class M1) by 8 elderly people carrying a heart rate monitor, and whose access manoeuvres were recorded by video cameras. Based on the Hilloskorpi et al. [1] model and by developing a method of truncation of the heart rate (HR) tests records - eliminating the component of the work biologically needed by the organism to keep its basal metabolic rate from the work each person performed – it was possible to evaluate how much energy each individual invested in each access manoeuver. Immediately after each test, and after the whole round of vehicles, each participant was surveyed for a subjective assessment of the difficulty of accessing to the cars. According to each of the above results, the HR objective measurements and the subjective opinion about the ease of access experienced by each individual, the vehicles were ranked by order of accessibility to the front and rear seats. The result of both rankings showed the orders of the similar vehicles, the potential of the method and a fair closeness between its results and the subjective, but real and unequivocal, judgments of the participants. (Author)

  12. Color-Space-Based Visual-MIMO for V2X Communication

    Directory of Open Access Journals (Sweden)

    Jai-Eun Kim

    2016-04-01

    Full Text Available In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol, and multiplexing-diversity mode transitions. In addition, in the V2X scenario of multiple access, we may achieve the simultaneous multiple access communication without node interferences by dividing the communication area using image processing. Finally, through numerical simulation, we show the superior SER performance of the visual-MIMO scheme compared with LED-PD communication and show the numerical result of the GCM based visual-MIMO channel capacity versus distance.

  13. iview: an interactive WebGL visualizer for protein-ligand complex.

    Science.gov (United States)

    Li, Hongjian; Leung, Kwong-Sak; Nakane, Takanori; Wong, Man-Hon

    2014-02-25

    Visualization of protein-ligand complex plays an important role in elaborating protein-ligand interactions and aiding novel drug design. Most existing web visualizers either rely on slow software rendering, or lack virtual reality support. The vital feature of macromolecular surface construction is also unavailable. We have developed iview, an easy-to-use interactive WebGL visualizer of protein-ligand complex. It exploits hardware acceleration rather than software rendering. It features three special effects in virtual reality settings, namely anaglyph, parallax barrier and oculus rift, resulting in visually appealing identification of intermolecular interactions. It supports four surface representations including Van der Waals surface, solvent excluded surface, solvent accessible surface and molecular surface. Moreover, based on the feature-rich version of iview, we have also developed a neat and tailor-made version specifically for our istar web platform for protein-ligand docking purpose. This demonstrates the excellent portability of iview. Using innovative 3D techniques, we provide a user friendly visualizer that is not intended to compete with professional visualizers, but to enable easy accessibility and platform independence.

  14. Communication between mother and her visually imapired child

    OpenAIRE

    Kolarič, Mojca

    2016-01-01

    Communication between mother and child has a significant impact on the development of children's language skills. Blindness or visual impairment limits access to information from the environment, which may have a negative impact on the development of communication between mother and child. In my master's thesis I focused on how the communication between mother and child alters due to visual impairment. In the theoretical part I introduced the importance of visual input in communication and...

  15. Providing Access and Visualization to Global Cloud Properties from GEO Satellites

    Science.gov (United States)

    Chee, T.; Nguyen, L.; Minnis, P.; Spangenberg, D.; Palikonda, R.; Ayers, J. K.

    2015-12-01

    Providing public access to cloud macro and microphysical properties is a key concern for the NASA Langley Research Center Cloud and Radiation Group. This work describes a tool and method that allows end users to easily browse and access cloud information that is otherwise difficult to acquire and manipulate. The core of the tool is an application-programming interface that is made available to the public. One goal of the tool is to provide a demonstration to end users so that they can use the dynamically generated imagery as an input into their own work flows for both image generation and cloud product requisition. This project builds upon NASA Langley Cloud and Radiation Group's experience with making real-time and historical satellite cloud product imagery accessible and easily searchable. As we see the increasing use of virtual supply chains that provide additional value at each link there is value in making satellite derived cloud product information available through a simple access method as well as allowing users to browse and view that imagery as they need rather than in a manner most convenient for the data provider. Using the Open Geospatial Consortium's Web Processing Service as our access method, we describe a system that uses a hybrid local and cloud based parallel processing system that can return both satellite imagery and cloud product imagery as well as the binary data used to generate them in multiple formats. The images and cloud products are sourced from multiple satellites and also "merged" datasets created by temporally and spatially matching satellite sensors. Finally, the tool and API allow users to access information that spans the time ranges that our group has information available. In the case of satellite imagery, the temporal range can span the entire lifetime of the sensor.

  16. Basic Visual Disciplines in Heritage Conservation: Outline of Selected Perspectives in Teaching and Learning

    Science.gov (United States)

    Lobovikov-Katz, A.

    2017-08-01

    Acknowledgement of the value of a basic freehand sketch by the information and communication community of researchers and developers brought about the advanced developments for the use of sketches as free input to complicated processes of computerized visualization, so as to make them more widely accessible. However, a sharp reduction and even exclusion of this and other basic visual disciplines from education in sciences, technology, engineering and architecture dramatically reduces the number of future users of such applications. The unique needs of conservation of cultural heritage pose specific challenges as well as encourage the formulation of innovative development tasks in related areas of information and communication technologies (ICT). This paper claims that the introduction of basic visual disciplines to both communities is essential to the effectiveness of integration of heritage conservation needs and the advanced ICT development of conservation value, and beyond. It provides an insight into the challenges and advantages of introducing these subjects in a relevant educational context, presents some examples of their teaching and learning in the modern environment, including e-learning, and sketches perspectives to their application.

  17. AR4VI: AR as an Accessibility Tool for People with Visual Impairments

    OpenAIRE

    Coughlan, James M.; Miele, Joshua

    2017-01-01

    Although AR technology has been largely dominated by visual media, a number of AR tools using both visual and auditory feedback have been developed specifically to assist people with low vision or blindness – an application domain that we term Augmented Reality for Visual Impairment (AR4VI). We describe two AR4VI tools developed at Smith-Kettlewell, as well as a number of pre-existing examples. We emphasize that AR4VI is a powerful tool with the potential to remove or significantly reduce a r...

  18. Control Deficit Subjects are Superior for Man-Made Objects on a Verbal Semantic Task

    Directory of Open Access Journals (Sweden)

    Carlos Roncero

    2014-04-01

    Full Text Available When semantic deficits occur following brain damage, the subjects generally show anomia as well as deficits on semantic matching tasks such as the Camels and Cactus test. Such individuals can be further characterized as demonstrating either a semantic control deficit or a storage deficit (Jeffries & Lambon Ralph, 2006. Semantic control subjects show improved performance when responses are constrained, but storage subjects do not. In the present study, we categorized 17 subjects with neurodegenerative diseases – Alzheimer’s disease and Primary Progressive Aphasia - as Semantic Storage or Semantic Control patterns of deficit, based on their performance on three semantic tasks—Naming, Cued Naming, and Word-to-Picture Matching. This was done independent of both the subject’s localization of brain damage and clinical diagnosis. Subjects who demonstrated impaired performance on the Naming task, but showed normal performance on Cued Naming and Word-to-Picture Matching, were classified as showing a control deficit (N = 8, while subjects who were impaired on all three semantic tasks were classified as anomic subjects with a storage deficit (N = 9. Despite only using these three semantic tasks, the identified sub-groups demonstrated different patterns of semantic knowledge consistent with either a control deficit or a storage deficit. The identified sub-groups, for example, were comparable for letter fluency, but subjects with a storage deficit were significantly worse for animal fluency. Accessing subjects’ semantic knowledge with the word and picture versions of the Camels and Cactus test, we also found that storage deficit subjects’ performance was equally poor on both versions compared to normal elderly participants, whereas control deficit subjects were relatively impaired only in the word version. Finally, comparing FDG PET scans for these subjects, we noted storage deficit subjects typically had bilateral temporal damage—all but one

  19. Evidence for Non-Opponent Coding of Colour Information in Human Visual Cortex: Selective Loss of “Green” Sensitivity in a Subject with Damaged Ventral Occipito-Temporal Cortex

    Science.gov (United States)

    Rauscher, Franziska G.; Plant, Gordon T.; James-Galton, Merle; Barbur, John L.

    2011-01-01

    Damage to ventral occipito-temporal extrastriate visual cortex leads to the syndrome of prosopagnosia often with coexisting cerebral achromatopsia. A patient with this syndrome resulting in a left upper homonymous quadrantanopia, prosopagnosia, and incomplete achromatopsia is described. Chromatic sensitivity was assessed at a number of locations in the intact visual field using a dynamic luminance contrast masking technique that isolates the use of colour signals. In normal subjects chromatic detection thresholds form an elliptical contour when plotted in the Commission Internationale d’Eclairage, (x-y), chromaticity diagram. Because the extraction of colour signals in early visual processing involves opponent mechanisms, subjects with Daltonism (congenital red/green loss of sensitivity) show symmetric increase in thresholds towards the long wavelength (“red”) and middle wavelength (“green”) regions of the spectrum locus. This is also the case with acquired loss of chromatic sensitivity as a result of retinal or optic nerve disease. Our patient’s results were an exception to this rule. Whilst his chromatic sensitivity in the central region of the visual field was reduced symmetrically for both “red/green” and “yellow/blue” directions in colour space, the subject’s lower left quadrant showed a marked asymmetry in “red/green” thresholds with the greatest loss of sensitivity towards the “green” region of the spectrum locus. This spatially localized asymmetric loss of “green” but not “red” sensitivity has not been reported previously in human vision. Such loss is consistent with selective damage of neural substrates in the visual cortex that process colour information, but are spectrally non-opponent. PMID:27956924

  20. High blood pressure and visual sensitivity

    Science.gov (United States)

    Eisner, Alvin; Samples, John R.

    2003-09-01

    The study had two main purposes: (1) to determine whether the foveal visual sensitivities of people treated for high blood pressure (vascular hypertension) differ from the sensitivities of people who have not been diagnosed with high blood pressure and (2) to understand how visual adaptation is related to standard measures of systemic cardiovascular function. Two groups of middle-aged subjects-hypertensive and normotensive-were examined with a series of test/background stimulus combinations. All subjects met rigorous inclusion criteria for excellent ocular health. Although the visual sensitivities of the two subject groups overlapped extensively, the age-related rate of sensitivity loss was, for some measures, greater for the hypertensive subjects, possibly because of adaptation differences between the two groups. Overall, the degree of steady-state sensitivity loss resulting from an increase of background illuminance (for 580-nm backgrounds) was slightly less for the hypertensive subjects. Among normotensive subjects, the ability of a bright (3.8-log-td), long-wavelength (640-nm) adapting background to selectively suppress the flicker response of long-wavelength-sensitive (LWS) cones was related inversely to the ratio of mean arterial blood pressure to heart rate. The degree of selective suppression was also related to heart rate alone, and there was evidence that short-term changes of cardiovascular response were important. The results suggest that (1) vascular hypertension, or possibly its treatment, subtly affects visual function even in the absence of eye disease and (2) changes in blood flow affect retinal light-adaptation processes involved in the selective suppression of the flicker response from LWS cones caused by bright, long-wavelength backgrounds.

  1. Rethinking ADA signage standards for low-vision accessibility.

    Science.gov (United States)

    Arditi, Aries

    2017-05-01

    Americans With Disabilities Act (ADA) and International Code Council (ICC) standards for accessible buildings and facilities affect design and construction of all new and renovated buildings throughout the United States, and form the basis for compliance with the ADA. While these standards may result in acceptable accessibility for people who are fully blind, they fall far short of what they could and should accomplish for those with low vision. In this article I critique the standards, detailing their lack of evidence base and other shortcomings. I suggest that simply making existing requirements stricter (e.g., by mandating larger letter size or higher contrasts) will not ensure visual accessibility and therefore cannot act as a valid basis for compliance with the law. I propose two remedies. First, requirements for visual characteristics of signs intended to improve access for those with low vision should be expressed not in terms of physical features, such as character height and contrast, but rather in terms of the distance at which a sign can be read by someone with nominally normal (20/20) visual acuity under expected lighting conditions for the installed environment. This would give sign designers greater choice in design parameters but place on them the burden of ensuring legibility. Second, mounting of directional signs, which are critical for effective and efficient wayfinding, should be required to be in consistent and approachable locations so that those with reduced acuity may view them at close distance.

  2. Is visual attention automatically attracted to one's own name?

    DEFF Research Database (Denmark)

    Bundesen, C; Kyllingsbæk, Søren; Houmann, K J

    1997-01-01

    Subjects were presented with briefly exposed visual displays of words that were common first names with a length of four to six letters. In the main experiment, each display consisted of four words: two names shown in red and two shown in white. The subject's task was to report the red names (tar......, visual attention was not automatically attracted by the subject's own name....

  3. Accurate metacognition for visual sensory memory representations.

    Science.gov (United States)

    Vandenbroucke, Annelinde R E; Sligte, Ilja G; Barrett, Adam B; Seth, Anil K; Fahrenfort, Johannes J; Lamme, Victor A F

    2014-04-01

    The capacity to attend to multiple objects in the visual field is limited. However, introspectively, people feel that they see the whole visual world at once. Some scholars suggest that this introspective feeling is based on short-lived sensory memory representations, whereas others argue that the feeling of seeing more than can be attended to is illusory. Here, we investigated this phenomenon by combining objective memory performance with subjective confidence ratings during a change-detection task. This allowed us to compute a measure of metacognition--the degree of knowledge that subjects have about the correctness of their decisions--for different stages of memory. We show that subjects store more objects in sensory memory than they can attend to but, at the same time, have similar metacognition for sensory memory and working memory representations. This suggests that these subjective impressions are not an illusion but accurate reflections of the richness of visual perception.

  4. Crossmodal Recruitment of the Ventral Visual Stream in Congenital Blindness

    Directory of Open Access Journals (Sweden)

    Maurice Ptito

    2012-01-01

    Full Text Available We used functional MRI (fMRI to test the hypothesis that blind subjects recruit the ventral visual stream during nonhaptic tactile-form recognition. Congenitally blind and blindfolded sighted control subjects were scanned after they had been trained during four consecutive days to perform a tactile-form recognition task with the tongue display unit (TDU. Both groups learned the task at the same rate. In line with our hypothesis, the fMRI data showed that during nonhaptic shape recognition, blind subjects activated large portions of the ventral visual stream, including the cuneus, precuneus, inferotemporal (IT, cortex, lateral occipital tactile vision area (LOtv, and fusiform gyrus. Control subjects activated area LOtv and precuneus but not cuneus, IT and fusiform gyrus. These results indicate that congenitally blind subjects recruit key regions in the ventral visual pathway during nonhaptic tactile shape discrimination. The activation of LOtv by nonhaptic tactile shape processing in blind and sighted subjects adds further support to the notion that this area subserves an abstract or supramodal representation of shape. Together with our previous findings, our data suggest that the segregation of the efferent projections of the primary visual cortex into a dorsal and ventral visual stream is preserved in individuals blind from birth.

  5. Unpredictable visual changes cause temporal memory averaging.

    Science.gov (United States)

    Ohyama, Junji; Watanabe, Katsumi

    2007-09-01

    Various factors influence the perceived timing of visual events. Yet, little is known about the ways in which transient visual stimuli affect the estimation of the timing of other visual events. In the present study, we examined how a sudden color change of an object would influence the remembered timing of another transient event. In each trial, subjects saw a green or red disk travel in circular motion. A visual flash (white frame) occurred at random times during the motion sequence. The color of the disk changed either at random times (unpredictable condition), at a fixed time relative to the motion sequence (predictable condition), or it did not change (no-change condition). The subjects' temporal memory of the visual flash in the predictable condition was as veridical as that in the no-change condition. In the unpredictable condition, however, the flash was reported to occur closer to the timing of the color change than actual timing. Thus, an unpredictable visual change distorts the temporal memory of another visual event such that the remembered moment of the event is closer to the timing of the unpredictable visual change.

  6. Effect of Postural Control Demands on Early Visual Evoked Potentials during a Subjective Visual Vertical Perception Task in Adolescents with Idiopathic Scoliosis.

    Science.gov (United States)

    Chang, Yi-Tzu; Meng, Ling-Fu; Chang, Chun-Ju; Lai, Po-Liang; Lung, Chi-Wen; Chern, Jen-Suh

    2017-01-01

    Subjective visual vertical (SVV) judgment and standing stability were separately investigated among patients with adolescent idiopathic scoliosis (AIS). Although, one study has investigated the central mechanism of stability control in the AIS population, the relationships between SVV, decreased standing stability, and AIS have never been investigated. Through event-related potentials (ERPs), the present study examined the effect of postural control demands (PDs) on AIS central mechanisms related to SVV judgment and standing stability to elucidate the time-serial stability control process. Thirteen AIS subjects (AIS group) and 13 age-matched adolescents (control group) aged 12-18 years were recruited. Each subject had to complete an SVV task (i.e., the modified rod-and-frame [mRAF] test) as a stimulus, with online electroencephalogram recording being performed in the following three standing postures: feet shoulder-width apart standing, feet together standing, and tandem standing. The behavioral performance in terms of postural stability (center of pressure excursion), SVV (accuracy and reaction time), and mRAF-locked ERPs (mean amplitude and peak latency of the P1, N1, and P2 components) was then compared between the AIS and control groups. In the behavioral domain, the results revealed that only the AIS group demonstrated a significantly accelerated SVV reaction time as the PDs increased. In the cerebral domain, significantly larger P2 mean amplitudes were observed during both feet shoulder-width-apart standing and feet together standing postures compared with during tandem standing. No group differences were noted in the cerebral domain. The results indicated that (1) during the dual-task paradigm, a differential behavioral strategy of accelerated SVV reaction time was observed in the AIS group only when the PDs increased and (2) the decrease in P2 mean amplitudes with the increase in the PD levels might be direct evidence of the competition for central

  7. Effect of Postural Control Demands on Early Visual Evoked Potentials during a Subjective Visual Vertical Perception Task in Adolescents with Idiopathic Scoliosis

    Directory of Open Access Journals (Sweden)

    Yi-Tzu Chang

    2017-06-01

    Full Text Available Subjective visual vertical (SVV judgment and standing stability were separately investigated among patients with adolescent idiopathic scoliosis (AIS. Although, one study has investigated the central mechanism of stability control in the AIS population, the relationships between SVV, decreased standing stability, and AIS have never been investigated. Through event-related potentials (ERPs, the present study examined the effect of postural control demands (PDs on AIS central mechanisms related to SVV judgment and standing stability to elucidate the time-serial stability control process. Thirteen AIS subjects (AIS group and 13 age-matched adolescents (control group aged 12–18 years were recruited. Each subject had to complete an SVV task (i.e., the modified rod-and-frame [mRAF] test as a stimulus, with online electroencephalogram recording being performed in the following three standing postures: feet shoulder-width apart standing, feet together standing, and tandem standing. The behavioral performance in terms of postural stability (center of pressure excursion, SVV (accuracy and reaction time, and mRAF-locked ERPs (mean amplitude and peak latency of the P1, N1, and P2 components was then compared between the AIS and control groups. In the behavioral domain, the results revealed that only the AIS group demonstrated a significantly accelerated SVV reaction time as the PDs increased. In the cerebral domain, significantly larger P2 mean amplitudes were observed during both feet shoulder-width-apart standing and feet together standing postures compared with during tandem standing. No group differences were noted in the cerebral domain. The results indicated that (1 during the dual-task paradigm, a differential behavioral strategy of accelerated SVV reaction time was observed in the AIS group only when the PDs increased and (2 the decrease in P2 mean amplitudes with the increase in the PD levels might be direct evidence of the competition for

  8. K-Means Subject Matter Expert Refined Topic Model Methodology

    Science.gov (United States)

    2017-01-01

    computing environment the Visual Basic for Applications ( VBA ) programming language presents the option as our programming language of choice. We propose...background, or access to other computational programming environments, to build topic models from free text datasets using a familiar Excel based...environment the restricts access to other software based text analytic tools. Opportunities to deploy developmental versions of the methodology and

  9. No Special Equipment Required: The Accessibility Features Built into the Windows and Macintosh Operating Systems make Computers Accessible for Students with Special Needs

    Science.gov (United States)

    Kimball,Walter H.; Cohen,Libby G.; Dimmick,Deb; Mills,Rick

    2003-01-01

    The proliferation of computers and other electronic learning devices has made knowledge and communication accessible to people with a wide range of abilities. Both Windows and Macintosh computers have accessibility options to help with many different special needs. This documents discusses solutions for: (1) visual impairments; (2) hearing…

  10. Data-Proximate Analysis and Visualization in the Cloud using Cloudstream, an Open-Source Application Streaming Technology Stack

    Science.gov (United States)

    Fisher, W. I.

    2017-12-01

    The rise in cloud computing, coupled with the growth of "Big Data", has lead to a migration away from local scientific data storage. The increasing size of remote scientific data sets increase, however, makes it difficult for scientists to subject them to large-scale analysis and visualization. These large datasets can take an inordinate amount of time to download; subsetting is a potential solution, but subsetting services are not yet ubiquitous. Data providers may also pay steep prices, as many cloud providers meter data based on how much data leaves their cloud service. The solution to this problem is a deceptively simple one; move data analysis and visualization tools to the cloud, so that scientists may perform data-proximate analysis and visualization. This results in increased transfer speeds, while egress costs are lowered or completely eliminated. Moving standard desktop analysis and visualization tools to the cloud is enabled via a technique called "Application Streaming". This technology allows a program to run entirely on a remote virtual machine while still allowing for interactivity and dynamic visualizations. When coupled with containerization technology such as Docker, we are able to easily deploy legacy analysis and visualization software to the cloud whilst retaining access via a desktop, netbook, a smartphone, or the next generation of hardware, whatever it may be. Unidata has created a Docker-based solution for easily adapting legacy software for Application Streaming. This technology stack, dubbed Cloudstream, allows desktop software to run in the cloud with little-to-no effort. The docker container is configured by editing text files, and the legacy software does not need to be modified in any way. This work will discuss the underlying technologies used by Cloudstream, and outline how to use Cloudstream to run and access an existing desktop application to the cloud.

  11. Tecnologia Acessível: reflexões sobre a utilização de recursos tecnológicos sonoros como acessibilidade aos textos literários para o aprendiz com deficiência visual

    Directory of Open Access Journals (Sweden)

    Ivan Vale de Sousa

    2015-03-01

    Full Text Available This paper presents a reflection on sound technological features such as accessibility to literary texts to people with visual disabilities. Address the importance of technology; discuss the possibilities of access to information and evidence the same learning situations for students with and without disabilities are goals of this proposal. Characterized bibliographicreflective nature, this production sees Dosvox Operating System and Program MecDaisy as educational assistive technology resources as well as the Braille system. The theoretical and reflective reasoning is based on contributions from authors such as, Lira (2004, Sonza (2004, Delpizzo (2005, Barbosa (2010 and others who argue and discuss about the accessibility of literary knowledge. Thus, it is expected that the subject contributes reflective process in supply and familiarity with the literature for visually impaired students in learning situations mediated by sound and technological resources available in the regular school.

  12. E-gaze : create gaze communication for peoplewith visual disability

    NARCIS (Netherlands)

    Qiu, S.; Osawa, H.; Hu, J.; Rauterberg, G.W.M.

    2015-01-01

    Gaze signals are frequently used by the sighted in social interactions as visual cues. However, these signals and cues are hardly accessible for people with visual disability. A conceptual design of E-Gaze glasses is proposed, assistive to create gaze communication between blind and sighted people

  13. JPEG XS call for proposals subjective evaluations

    Science.gov (United States)

    McNally, David; Bruylants, Tim; Willème, Alexandre; Ebrahimi, Touradj; Schelkens, Peter; Macq, Benoit

    2017-09-01

    In March 2016 the Joint Photographic Experts Group (JPEG), formally known as ISO/IEC SC29 WG1, issued a call for proposals soliciting compression technologies for a low-latency, lightweight and visually transparent video compression scheme. Within the JPEG family of standards, this scheme was denominated JPEG XS. The subjective evaluation of visually lossless compressed video sequences at high resolutions and bit depths poses particular challenges. This paper describes the adopted procedures, the subjective evaluation setup, the evaluation process and summarizes the obtained results which were achieved in the context of the JPEG XS standardization process.

  14. Optical and visual performance of aspheric soft contact lenses.

    Science.gov (United States)

    Efron, Suzanne; Efron, Nathan; Morgan, Philip B

    2008-03-01

    This study was conducted to investigate whether aspheric design soft contact lenses reduce ocular aberrations and result in better visual acuity and subjective appreciation of clinical performance compared with spherical soft contact lenses. A unilateral, double-masked, randomized and controlled study was undertaken in which ocular aberrations and high and low contrast logMAR visual acuity were measured on myopic subjects who wore aspheric design (Biomedics 55 Evolution, CooperVision) and spherical design (Biomedics 55, CooperVision) soft contact lenses. Ten subjects who had about -2.00 D myopia wore -2.00 D lenses and 10 subjects who had about -5.00 D myopia wore -5.00 D lenses. Measurements were made under photopic and mesopic lighting conditions. Subjects were invited to grade comfort, vision in photopic and mesopic conditions, and overall impression with the two lens types on 100 unit visual analogue scales. There was no significant difference in high contrast or low contrast visual acuity between the two lens designs of either power under photopic or mesopic conditions. Both lens designs displayed lower levels of spherical aberration compared with the "no lens" condition under photopic and mesopic light levels (p designs. There were no statistically significant differences in subjective appreciation of clinical performance between lens designs or lens powers. At least with respect to the brand of lenses tested, the fitting of aspheric design soft contact lenses does not result in superior visual acuity, aberration control, or subjective appreciation compared with equivalent spherical design soft contact lenses.

  15. Visualization of ocean forecast in BYTHOS

    Science.gov (United States)

    Zhuk, E.; Zodiatis, G.; Nikolaidis, A.; Stylianou, S.; Karaolia, A.

    2016-08-01

    The Cyprus Oceanography Center has been constantly searching for new ideas for developing and implementing innovative methods and new developments concerning the use of Information Systems in Oceanography, to suit both the Center's monitoring and forecasting products. Within the frame of this scope two major online managing and visualizing data systems have been developed and utilized, those of CYCOFOS and BYTHOS. The Cyprus Coastal Ocean Forecasting and Observing System - CYCOFOS provides a variety of operational predictions such as ultra high, high and medium resolution ocean forecasts in the Levantine Basin, offshore and coastal sea state forecasts in the Mediterranean and Black Sea, tide forecasting in the Mediterranean, ocean remote sensing in the Eastern Mediterranean and coastal and offshore monitoring. As a rich internet application, BYTHOS enables scientists to search, visualize and download oceanographic data online and in real time. The recent improving of BYTHOS system is the extension with access and visualization of CYCOFOS data and overlay forecast fields and observing data. The CYCOFOS data are stored at OPENDAP Server in netCDF format. To search, process and visualize it the php and python scripts were developed. Data visualization is achieved through Mapserver. The BYTHOS forecast access interface allows to search necessary forecasting field by recognizing type, parameter, region, level and time. Also it provides opportunity to overlay different forecast and observing data that can be used for complex analyze of sea basin aspects.

  16. Activation of lateral geniculate nucleus and primary visual cortex as detected by functional magnetic resonance imaging in normal subjects and in patients with visual disturbance

    Energy Technology Data Exchange (ETDEWEB)

    Miki, Atsushi [Niigata Univ. (Japan). Graduate School of Medical and Dental Sciences

    2002-12-01

    Functional magnetic resonance imaging (fMRI) during visual stimulation can detect regional cerebral blood flow changes that reflect neural activity in the lateral geniculate nucleus and primary visual cortex, which are major relay points in the human afferent visual system. FMRI has been used in the clinical evaluation of visual disorders such as homonymous hemianopia and unilateral eye diseases (optic neuritis, amblyopia, and so on). Future development in the data acquisition and data analysis may facilitate the use of fMRI for the management of patients with visual deficits and understanding of the visual disorders. (author)

  17. Activation of lateral geniculate nucleus and primary visual cortex as detected by functional magnetic resonance imaging in normal subjects and in patients with visual disturbance

    International Nuclear Information System (INIS)

    Miki, Atsushi

    2002-01-01

    Functional magnetic resonance imaging (fMRI) during visual stimulation can detect regional cerebral blood flow changes that reflect neural activity in the lateral geniculate nucleus and primary visual cortex, which are major relay points in the human afferent visual system. FMRI has been used in the clinical evaluation of visual disorders such as homonymous hemianopia and unilateral eye diseases (optic neuritis, amblyopia, and so on). Future development in the data acquisition and data analysis may facilitate the use of fMRI for the management of patients with visual deficits and understanding of the visual disorders. (author)

  18. Time dependent accessibility

    OpenAIRE

    Kaza, Nikhil

    2015-01-01

    Many place based accessibility studies ignore the time component. Relying on theoretical frameworks that treat distance between two fixed points as constant, these methods ignore the diurnal and seasonal changes in accessibility. Network distances between two nodes are dependent on the network structure and weight distribution on the edges. These weights can change quite frequently and the network structure itself is subject to modification because of availability and unavailability of links ...

  19. Biometrics: Accessibility challenge or opportunity?

    Directory of Open Access Journals (Sweden)

    Ramon Blanco-Gonzalo

    Full Text Available Biometric recognition is currently implemented in several authentication contexts, most recently in mobile devices where it is expected to complement or even replace traditional authentication modalities such as PIN (Personal Identification Number or passwords. The assumed convenience characteristics of biometrics are transparency, reliability and ease-of-use, however, the question of whether biometric recognition is as intuitive and straightforward to use is open to debate. Can biometric systems make some tasks easier for people with accessibility concerns? To investigate this question, an accessibility evaluation of a mobile app was conducted where test subjects withdraw money from a fictitious ATM (Automated Teller Machine scenario. The biometric authentication mechanisms used include face, voice, and fingerprint. Furthermore, we employed traditional modalities of PIN and pattern in order to check if biometric recognition is indeed a real improvement. The trial test subjects within this work were people with real-life accessibility concerns. A group of people without accessibility concerns also participated, providing a baseline performance. Experimental results are presented concerning performance, HCI (Human-Computer Interaction and accessibility, grouped according to category of accessibility concern. Our results reveal links between individual modalities and user category establishing guidelines for future accessible biometric products.

  20. Adjustable typography: an approach to enhancing low vision text accessibility.

    Science.gov (United States)

    Arditi, Aries

    2004-04-15

    Millions of people have low vision, a disability condition caused by uncorrectable or partially correctable disorders of the eye. The primary goal of low vision rehabilitation is increasing access to printed material. This paper describes how adjustable typography, a computer graphic approach to enhancing text accessibility, can play a role in this process, by allowing visually-impaired users to customize fonts to maximize legibility according to their own visual needs. Prototype software and initial testing of the concept is described. The results show that visually-impaired users tend to produce a variety of very distinct fonts, and that the adjustment process results in greatly enhanced legibility. But this initial testing has not yet demonstrated increases in legibility over and above the legibility of highly legible standard fonts such as Times New Roman.

  1. 1001 Proteomes: a functional proteomics portal for the analysis of Arabidopsis thaliana accessions.

    Science.gov (United States)

    Joshi, Hiren J; Christiansen, Katy M; Fitz, Joffrey; Cao, Jun; Lipzen, Anna; Martin, Joel; Smith-Moritz, A Michelle; Pennacchio, Len A; Schackwitz, Wendy S; Weigel, Detlef; Heazlewood, Joshua L

    2012-05-15

    The sequencing of over a thousand natural strains of the model plant Arabidopsis thaliana is producing unparalleled information at the genetic level for plant researchers. To enable the rapid exploitation of these data for functional proteomics studies, we have created a resource for the visualization of protein information and proteomic datasets for sequenced natural strains of A. thaliana. The 1001 Proteomes portal can be used to visualize amino acid substitutions or non-synonymous single-nucleotide polymorphisms in individual proteins of A. thaliana based on the reference genome Col-0. We have used the available processed sequence information to analyze the conservation of known residues subject to protein phosphorylation among these natural strains. The substitution of amino acids in A. thaliana natural strains is heavily constrained and is likely a result of the conservation of functional attributes within proteins. At a practical level, we demonstrate that this information can be used to clarify ambiguously defined phosphorylation sites from phosphoproteomic studies. Protein sets of available natural variants are available for download to enable proteomic studies on these accessions. Together this information can be used to uncover the possible roles of specific amino acids in determining the structure and function of proteins in the model plant A. thaliana. An online portal to enable the community to exploit these data can be accessed at http://1001proteomes.masc-proteomics.org/

  2. Quantum production. Visual Media Services at Fermilab

    CERN Multimedia

    Klapow, S

    2003-01-01

    Visual Media Services, a department of eight full-time employees at Fermi National Accelerator Laboratory, is responsible for translating the laboratories research into accessible and engaging media (1 page)

  3. Visual memory-deficit amnesia: A distinct amnesic presentation and etiology

    OpenAIRE

    Rubin, David C.; Greenberg, Daniel L.

    1998-01-01

    We describe a form of amnesia, which we have called visual memory-deficit amnesia, that is caused by damage to areas of the visual system that store visual information. Because it is caused by a deficit in access to stored visual material and not by an impaired ability to encode or retrieve new material, it has the otherwise infrequent properties of a more severe retrograde than anterograde amnesia with no temporal gradient in the retrograde amnesia. Of the 11 cases of long-term visual memory...

  4. How Many Subjects are Needed for a Visual Field Normative Database? A Comparison of Ground Truth and Bootstrapped Statistics.

    Science.gov (United States)

    Phu, Jack; Bui, Bang V; Kalloniatis, Michael; Khuu, Sieu K

    2018-03-01

    The number of subjects needed to establish the normative limits for visual field (VF) testing is not known. Using bootstrap resampling, we determined whether the ground truth mean, distribution limits, and standard deviation (SD) could be approximated using different set size ( x ) levels, in order to provide guidance for the number of healthy subjects required to obtain robust VF normative data. We analyzed the 500 Humphrey Field Analyzer (HFA) SITA-Standard results of 116 healthy subjects and 100 HFA full threshold results of 100 psychophysically experienced healthy subjects. These VFs were resampled (bootstrapped) to determine mean sensitivity, distribution limits (5th and 95th percentiles), and SD for different ' x ' and numbers of resamples. We also used the VF results of 122 glaucoma patients to determine the performance of ground truth and bootstrapped results in identifying and quantifying VF defects. An x of 150 (for SITA-Standard) and 60 (for full threshold) produced bootstrapped descriptive statistics that were no longer different to the original distribution limits and SD. Removing outliers produced similar results. Differences between original and bootstrapped limits in detecting glaucomatous defects were minimized at x = 250. Ground truth statistics of VF sensitivities could be approximated using set sizes that are significantly smaller than the original cohort. Outlier removal facilitates the use of Gaussian statistics and does not significantly affect the distribution limits. We provide guidance for choosing the cohort size for different levels of error when performing normative comparisons with glaucoma patients.

  5. Multi-disciplinary data organization and visualization models for clinical and pre-clinical studies: A case study in the application of proton beam radiosurgery for treating spinal cord injury related pain

    Science.gov (United States)

    Verma, Sneha K.; Liu, Brent J.

    2016-03-01

    An increasing adoption of electronic medical records has made information more accessible to clinicians and researchers through dedicated systems such as HIS, RIS and PACS. The speed and the amount at which information are generated in a multi-institutional clinical study make the problem complicated compared to day-to-day hospital workflow. Often, increased access to the information does not translate into the efficient use of that information. Therefore, it becomes crucial to establish models which can be used to organize and visualize multi-disciplinary data. Good visualization in turn makes it easy for clinical decision-makers to reach a conclusion within a small span of time. In a clinical study involving multi-disciplinary data and multiple user groups who need access to the same data and presentation states based on the stage of the clinical trial or the task are crucial within the workflow. Therefore, in order to demonstrate the conceptual system design and system workflow, we will be presenting a clinical trial based on application of proton beam for radiosurgery which will utilize our proposed system. For demonstrating user role and visualization design purposes, we will be focusing on three different user groups which are researchers involved in patient enrollment and recruitment, clinicians involved in treatment and imaging review and lastly the principle investigators involved in monitoring progress of clinical study. Also datasets for each phase of the clinical study including preclinical and clinical data as it related to subject enrollment, subject recruitment (classifier), treatment (DICOM), imaging, and pathological analysis (protein staining) of outcomes.

  6. SCSODC: Integrating Ocean Data for Visualization Sharing and Application

    Science.gov (United States)

    Xu, C.; Li, S.; Wang, D.; Xie, Q.

    2014-02-01

    The South China Sea Ocean Data Center (SCSODC) was founded in 2010 in order to improve collecting and managing of ocean data of the South China Sea Institute of Oceanology (SCSIO). The mission of SCSODC is to ensure the long term scientific stewardship of ocean data, information and products - collected through research groups, monitoring stations and observation cruises - and to facilitate the efficient use and distribution to possible users. However, data sharing and applications were limited due to the characteristics of distribution and heterogeneity that made it difficult to integrate the data. To surmount those difficulties, the Data Sharing System has been developed by the SCSODC using the most appropriate information management and information technology. The Data Sharing System uses open standards and tools to promote the capability to integrate ocean data and to interact with other data portals or users and includes a full range of processes such as data discovery, evaluation and access combining C/S and B/S mode. It provides a visualized management interface for the data managers and a transparent and seamless data access and application environment for users. Users are allowed to access data using the client software and to access interactive visualization application interface via a web browser. The architecture, key technologies and functionality of the system are discussed briefly in this paper. It is shown that the system of SCSODC is able to implement web visualization sharing and seamless access to ocean data in a distributed and heterogeneous environment.

  7. Visual Working Memory Capacity and Proactive Interference

    OpenAIRE

    Hartshorne, Joshua

    2008-01-01

    BACKGROUND: Visual working memory capacity is extremely limited and appears to be relatively immune to practice effects or the use of explicit strategies. The recent discovery that visual working memory tasks, like verbal working memory tasks, are subject to proactive interference, coupled with the fact that typical visual working memory tasks are particularly conducive to proactive interference, suggests that visual working memory capacity may be systematically under-estimated. METHODOLOGY/P...

  8. Efficiency of conscious access improves with coupling of slow and fast neural oscillations.

    Science.gov (United States)

    Nakatani, Chie; Raffone, Antonino; van Leeuwen, Cees

    2014-05-01

    Global workspace access is considered as a critical factor for the ability to report a visual target. A plausible candidate mechanism for global workspace access is coupling of slow and fast brain activity. We studied coupling in EEG data using cross-frequency phase-amplitude modulation measurement between delta/theta phases and beta/gamma amplitudes from two experimental sessions, held on different days, of a typical attentional blink (AB) task, implying conscious access to targets. As the AB effect improved with practice between sessions, theta-gamma and theta-beta coupling increased generically. Most importantly, practice effects observed in delta-gamma and delta-beta couplings were specific to performance on the AB task. In particular, delta-gamma coupling showed the largest increase in cases of correct target detection in the most challenging AB conditions. All these practice effects were observed in the right temporal region. Given that the delta band is the main frequency of the P3 ERP, which is a marker of global workspace activity for conscious access, and because the gamma band is involved in visual object processing, the current results substantiate the role of phase-amplitude modulation in conscious access to visual target representations.

  9. Conceptual and visual features contribute to visual memory for natural images.

    Directory of Open Access Journals (Sweden)

    Gesche M Huebner

    Full Text Available We examined the role of conceptual and visual similarity in a memory task for natural images. The important novelty of our approach was that visual similarity was determined using an algorithm [1] instead of being judged subjectively. This similarity index takes colours and spatial frequencies into account. For each target, four distractors were selected that were (1 conceptually and visually similar, (2 only conceptually similar, (3 only visually similar, or (4 neither conceptually nor visually similar to the target image. Participants viewed 219 images with the instruction to memorize them. Memory for a subset of these images was tested subsequently. In Experiment 1, participants performed a two-alternative forced choice recognition task and in Experiment 2, a yes/no-recognition task. In Experiment 3, testing occurred after a delay of one week. We analyzed the distribution of errors depending on distractor type. Performance was lowest when the distractor image was conceptually and visually similar to the target image, indicating that both factors matter in such a memory task. After delayed testing, these differences disappeared. Overall performance was high, indicating a large-capacity, detailed visual long-term memory.

  10. Balancing awareness: Vestibular signals modulate visual consciousness in the absence of awareness.

    Science.gov (United States)

    Salomon, Roy; Kaliuzhna, Mariia; Herbelin, Bruno; Blanke, Olaf

    2015-11-01

    The processing of visual and vestibular information is crucial for perceiving self-motion. Visual cues, such as optic flow, have been shown to induce and alter vestibular percepts, yet the role of vestibular information in shaping visual awareness remains unclear. Here we investigated if vestibular signals influence the access to awareness of invisible visual signals. Using natural vestibular stimulation (passive yaw rotations) on a vestibular self-motion platform, and optic flow masked through continuous flash suppression (CFS) we tested if congruent visual-vestibular information would break interocular suppression more rapidly than incongruent information. We found that when the unseen optic flow was congruent with the vestibular signals perceptual suppression as quantified with the CFS paradigm was broken more rapidly than when it was incongruent. We argue that vestibular signals impact the formation of visual awareness through enhanced access to awareness for congruent multisensory stimulation. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Advocating for a Population-Specific Health Literacy for People With Visual Impairments.

    Science.gov (United States)

    Harrison, Tracie; Lazard, Allison

    2015-01-01

    Health literacy, the ability to access, process, and understand health information, is enhanced by the visual senses among people who are typically sighted. Emotions, meaning, speed of knowledge transfer, level of attention, and degree of relevance are all manipulated by the visual design of health information when people can see. When consumers of health information are blind or visually impaired, they access, process, and understand their health information in a multitude of methods using a variety of accommodations depending upon their severity and type of impairment. They are taught, or they learn how, to accommodate their differences by using alternative sensory experiences and interpretations. In this article, we argue that due to the unique and powerful aspects of visual learning and due to the differences in knowledge creation when people are not visually oriented, health literacy must be considered a unique construct for people with visual impairment, which requires a distinctive theoretical basis for determining the impact of their mind-constructed representations of health.

  12. An Expert System Approach to Online Catalog Subject Searching.

    Science.gov (United States)

    Khoo, Christopher S. G.; Poo, Danny C. C.

    1994-01-01

    Reviews methods to improve online catalogs for subject searching and describes the design of an expert system front-end to improve subject access in online public access catalogs that focuses on search strategies. Implementation of a prototype system at the National University of Singapore is described, and reformulation strategies are discussed.…

  13. 5 CFR 2606.203 - Granting access.

    Science.gov (United States)

    2010-01-01

    ... Access to Records and Accounting of Disclosures § 2606.203 Granting access. (a) The methods for allowing... documentation will be required for the disclosure to the data subject of information required to be made...

  14. Color-Space-Based Visual-MIMO for V2X Communication †

    Science.gov (United States)

    Kim, Jai-Eun; Kim, Ji-Won; Park, Youngil; Kim, Ki-Doo

    2016-01-01

    In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol), and multiplexing-diversity mode transitions. In addition, in the V2X scenario of multiple access, we may achieve the simultaneous multiple access communication without node interferences by dividing the communication area using image processing. Finally, through numerical simulation, we show the superior SER performance of the visual-MIMO scheme compared with LED-PD communication and show the numerical result of the GCM based visual-MIMO channel capacity versus distance. PMID:27120603

  15. The mapping of the visual field onto the dorso-lateral tectum of the pigeon (Columba livia) and its relations with retinal specializations.

    Science.gov (United States)

    Letelier, Juan-Carlos; Marin, Gonzalo; Sentis, Elisa; Tenreiro, Andrea; Fredes, Felipe; Mpodozis, Jorge

    2004-01-30

    Most of the physiological studies of the pigeon retino-tectal visual pathway have investigated the accessible tectum, a small dorso-lateral tectal section that can be easily accessed by a simple craniotomy. However, at present we lack a detailed study of the topographical arrangement between the visual field, the retina and the accessible tectum. In particular, it is not known which section of the visual field is mapped onto the accessible tectum, and which of the specialized retinal areas mediates this projection. Here we determined, using local field potential (LFP) recordings and reverse retinoscopy, the shape, size and position in the visual space of the portion of the visual field mapped onto the accessible tectum (called here the accessible visual field, or AVF). Using this data and the mapping of Nalbach et al. [Vis. Res. 30 (4) (1990) 529], the retinal area corresponding to the AVF was determined. Such retinal area was also directly delimited by means of retrograde transport of DiI. The results indicate that the AVF is a triangular perifoveal zone encompassing only 15% of total visual field. The retinal region corresponding to the AVF has the shape of an elongated triangle that runs parallel to the visual equator and contains the fovea, the tip of the pecten, a perifoveal region of the yellow field and a small crescent of the red field. In agreement with this anatomical heterogeneity, visual evoked potentials measured in different parts of the accessible tectum present steep variations in shape and size. These results are helpful to better design and interpret anatomical and physiological experiments involving the pigeon's visual system.

  16. Visual Ecology and the Development of Visually Guided Behavior in the Cuttlefish

    Directory of Open Access Journals (Sweden)

    Anne-Sophie Darmaillacq

    2017-06-01

    Full Text Available Cuttlefish are highly visual animals, a fact reflected in the large size of their eyes and visual-processing centers of their brain. Adults detect their prey visually, navigate using visual cues such as landmarks or the e-vector of polarized light and display intense visual patterns during mating and agonistic encounters. Although much is known about the visual system in adult cuttlefish, few studies have investigated its development and that of visually-guided behavior in juveniles. This review summarizes the results of studies of visual development in embryos and young juveniles. The visual system is the last to develop, as in vertebrates, and is functional before hatching. Indeed, embryonic exposure to prey, shelters or complex background alters postembryonic behavior. Visual acuity and lateralization, and polarization sensitivity improve throughout the first months after hatching. The production of body patterning in juveniles is not the simple stimulus-response process commonly presented in the literature. Rather, it likely requires the complex integration of visual information, and is subject to inter-individual differences. Though the focus of this review is vision in cuttlefish, it is important to note that other senses, particularly sensitivity to vibration and to waterborne chemical signals, also play a role in behavior. Considering the multimodal sensory dimensions of natural stimuli and their integration and processing by individuals offer new exciting avenues of future inquiry.

  17. Visual Ecology and the Development of Visually Guided Behavior in the Cuttlefish.

    Science.gov (United States)

    Darmaillacq, Anne-Sophie; Mezrai, Nawel; O'Brien, Caitlin E; Dickel, Ludovic

    2017-01-01

    Cuttlefish are highly visual animals, a fact reflected in the large size of their eyes and visual-processing centers of their brain. Adults detect their prey visually, navigate using visual cues such as landmarks or the e -vector of polarized light and display intense visual patterns during mating and agonistic encounters. Although much is known about the visual system in adult cuttlefish, few studies have investigated its development and that of visually-guided behavior in juveniles. This review summarizes the results of studies of visual development in embryos and young juveniles. The visual system is the last to develop, as in vertebrates, and is functional before hatching. Indeed, embryonic exposure to prey, shelters or complex background alters postembryonic behavior. Visual acuity and lateralization, and polarization sensitivity improve throughout the first months after hatching. The production of body patterning in juveniles is not the simple stimulus-response process commonly presented in the literature. Rather, it likely requires the complex integration of visual information, and is subject to inter-individual differences. Though the focus of this review is vision in cuttlefish, it is important to note that other senses, particularly sensitivity to vibration and to waterborne chemical signals, also play a role in behavior. Considering the multimodal sensory dimensions of natural stimuli and their integration and processing by individuals offer new exciting avenues of future inquiry.

  18. DisVis: Visualizing Discussion Threads in Online Health Communities.

    Science.gov (United States)

    Nakikj, Drashko; Mamykina, Lena

    2016-01-01

    An increasing number of individuals turn to online health communities (OHC) for information, advice and support about their health condition or disease. As a result of users' active participation, these forums store overwhelming volumes of information, which can make access to this information challenging and frustrating. To help overcome this problem we designed a discussion visualization tool DisVis. DisVis includes features for overviewing, browsing and finding particular information in a discussion. In a between subjects study, we tested the impact of DisVis on individuals' ability to provide an overview of a discussion, find topics of interest and summarize opinions. The study showed that after using the tool, the accuracy of participants' answers increased by 68% (p-value = 0.023) while at the same time exhibiting trends for reducing the time to answer by 38% with no statistical significance (p-value = 0.082). Qualitative interviews showed general enthusiasm regarding tools for improving browsing and searching for information within discussion forums, suggested different usage scenarios, highlighted opportunities for improving the design of DisVis, and outlined new directions for visualizing user-generated content within OHCs.

  19. Ultra-scale Visualization Climate Data Analysis Tools (UV-CDAT)

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Silva, Claudio [New York Univ. (NYU), NY (United States). Computer Science and Engineering Dept.

    2013-09-30

    For the past three years, a large analysis and visualization effort—funded by the Department of Energy’s Office of Biological and Environmental Research (BER), the National Aeronautics and Space Administration (NASA), and the National Oceanic and Atmospheric Administration (NOAA)—has brought together a wide variety of industry-standard scientific computing libraries and applications to create Ultra-scale Visualization Climate Data Analysis Tools (UV-CDAT) to serve the global climate simulation and observational research communities. To support interactive analysis and visualization, all components connect through a provenance application–programming interface to capture meaningful history and workflow. Components can be loosely coupled into the framework for fast integration or tightly coupled for greater system functionality and communication with other components. The overarching goal of UV-CDAT is to provide a new paradigm for access to and analysis of massive, distributed scientific data collections by leveraging distributed data architectures located throughout the world. The UV-CDAT framework addresses challenges in analysis and visualization and incorporates new opportunities, including parallelism for better efficiency, higher speed, and more accurate scientific inferences. Today, it provides more than 600 users access to more analysis and visualization products than any other single source.

  20. Social Identity Mapping: A procedure for visual representation and assessment of subjective multiple group memberships.

    Science.gov (United States)

    Cruwys, Tegan; Steffens, Niklas K; Haslam, S Alexander; Haslam, Catherine; Jetten, Jolanda; Dingle, Genevieve A

    2016-12-01

    In this research, we introduce Social Identity Mapping (SIM) as a method for visually representing and assessing a person's subjective network of group memberships. To provide evidence of its utility, we report validating data from three studies (two longitudinal), involving student, community, and clinical samples, together comprising over 400 participants. Results indicate that SIM is easy to use, internally consistent, with good convergent and discriminant validity. Each study also illustrates the ways that SIM can be used to address a range of novel research questions. Study 1 shows that multiple positive group memberships are a particularly powerful predictor of well-being. Study 2 shows that social support is primarily given and received within social groups and that only in-group support is beneficial for well-being. Study 3 shows that improved mental health following a social group intervention is attributable to an increase in group compatibility. In this way, the studies demonstrate the capacity for SIM to make a contribution both to the development of social-psychological theory and to its practical application. © 2016 The British Psychological Society.

  1. Virtual Visual Effect of Hospital Waiting Room on Pain Modulation in Healthy Subjects and Patients with Chronic Migraine

    Directory of Open Access Journals (Sweden)

    Marina de Tommaso

    2013-01-01

    Full Text Available Environmental context has an important impact on health and well being. We aimed to test the effects of a visual distraction induced by classical hospital waiting room (RH versus an ideal room with a sea view (IH, both represented in virtual reality (VR, on subjective sensation and cortical responses induced by painful laser stimuli (LEPs in healthy volunteers and patients with chronic migraine (CM. Sixteen CM and 16 controls underwent 62 channels LEPs from the right hand, during a fully immersive VR experience, where two types of waiting rooms were simulated. The RH simulated a classical hospital waiting room while the IH represented a room with sea viewing. CM patients showed a reduction of laser pain rating and vertex LEPs during the IH vision. The sLORETA analysis confirmed that in CM patients the two VR simulations induced a different modulation of bilateral parietal cortical areas (precuneus and superior parietal lobe, and superior frontal and cingulate girus, in respect to controls. The architectural context may interfere with pain perception, depending upon the status of subject. Many variables may change patients’ outcome and support the use of VR technology to test the best conditions for their management.

  2. Learning to Recognize Patterns: Changes in the Visual Field with Familiarity

    Science.gov (United States)

    Bebko, James M.; Uchikawa, Keiji; Saida, Shinya; Ikeda, Mitsuo

    1995-01-01

    Two studies were conducted to investigate changes which take place in the visual information processing of novel stimuli as they become familiar. Japanese writing characters (Hiragana and Kanji) which were unfamiliar to two native English speaking subjects were presented using a moving window technique to restrict their visual fields. Study time for visual recognition was recorded across repeated sessions, and with varying visual field restrictions. The critical visual field was defined as the size of the visual field beyond which further increases did not improve the speed of recognition performance. In the first study, when the Hiragana patterns were novel, subjects needed to see about half of the entire pattern simultaneously to maintain optimal performance. However, the critical visual field size decreased as familiarity with the patterns increased. These results were replicated in the second study with more complex Kanji characters. In addition, the critical field size decreased as pattern complexity decreased. We propose a three component model of pattern perception. In the first stage a representation of the stimulus must be constructed by the subject, and restricting of the visual field interferes dramatically with this component when stimuli are unfamiliar. With increased familiarity, subjects become able to reconstruct a previous representation from very small, unique segments of the pattern, analogous to the informativeness areas hypothesized by Loftus and Mackworth [J. Exp. Psychol., 4 (1978) 565].

  3. OpinionSeer: interactive visualization of hotel customer feedback.

    Science.gov (United States)

    Wu, Yingcai; Wei, Furu; Liu, Shixia; Au, Norman; Cui, Weiwei; Zhou, Hong; Qu, Huamin

    2010-01-01

    The rapid development of Web technology has resulted in an increasing number of hotel customers sharing their opinions on the hotel services. Effective visual analysis of online customer opinions is needed, as it has a significant impact on building a successful business. In this paper, we present OpinionSeer, an interactive visualization system that could visually analyze a large collection of online hotel customer reviews. The system is built on a new visualization-centric opinion mining technique that considers uncertainty for faithfully modeling and analyzing customer opinions. A new visual representation is developed to convey customer opinions by augmenting well-established scatterplots and radial visualization. To provide multiple-level exploration, we introduce subjective logic to handle and organize subjective opinions with degrees of uncertainty. Several case studies illustrate the effectiveness and usefulness of OpinionSeer on analyzing relationships among multiple data dimensions and comparing opinions of different groups. Aside from data on hotel customer feedback, OpinionSeer could also be applied to visually analyze customer opinions on other products or services.

  4. The Visual Geophysical Exploration Environment: A Multi-dimensional Scientific Visualization

    Science.gov (United States)

    Pandya, R. E.; Domenico, B.; Murray, D.; Marlino, M. R.

    2003-12-01

    The Visual Geophysical Exploration Environment (VGEE) is an online learning environment designed to help undergraduate students understand fundamental Earth system science concepts. The guiding principle of the VGEE is the importance of hands-on interaction with scientific visualization and data. The VGEE consists of four elements: 1) an online, inquiry-based curriculum for guiding student exploration; 2) a suite of El Nino-related data sets adapted for student use; 3) a learner-centered interface to a scientific visualization tool; and 4) a set of concept models (interactive tools that help students understand fundamental scientific concepts). There are two key innovations featured in this interactive poster session. One is the integration of concept models and the visualization tool. Concept models are simple, interactive, Java-based illustrations of fundamental physical principles. We developed eight concept models and integrated them into the visualization tool to enable students to probe data. The ability to probe data using a concept model addresses the common problem of transfer: the difficulty students have in applying theoretical knowledge to everyday phenomenon. The other innovation is a visualization environment and data that are discoverable in digital libraries, and installed, configured, and used for investigations over the web. By collaborating with the Integrated Data Viewer developers, we were able to embed a web-launchable visualization tool and access to distributed data sets into the online curricula. The Thematic Real-time Environmental Data Distributed Services (THREDDS) project is working to provide catalogs of datasets that can be used in new VGEE curricula under development. By cataloging this curricula in the Digital Library for Earth System Education (DLESE), learners and educators can discover the data and visualization tool within a framework that guides their use.

  5. Subconscious visual cues during movement execution allow correct online choice reactions.

    Directory of Open Access Journals (Sweden)

    Christian Leukel

    Full Text Available Part of the sensory information is processed by our central nervous system without conscious perception. Subconscious processing has been shown to be capable of triggering motor reactions. In the present study, we asked the question whether visual information, which is not consciously perceived, could influence decision-making in a choice reaction task. Ten healthy subjects (28 ± 5 years executed two different experimental protocols. In the Motor reaction protocol, a visual target cue was shown on a computer screen. Depending on the displayed cue, subjects had to either complete a reaching movement (go-condition or had to abort the movement (stop-condition. The cue was presented with different display durations (20-160 ms. In the second Verbalization protocol, subjects verbalized what they experienced on the screen. Again, the cue was presented with different display durations. This second protocol tested for conscious perception of the visual cue. The results of this study show that subjects achieved significantly more correct responses in the Motor reaction protocol than in the Verbalization protocol. This difference was only observed at the very short display durations of the visual cue. Since correct responses in the Verbalization protocol required conscious perception of the visual information, our findings imply that the subjects performed correct motor responses to visual cues, which they were not conscious about. It is therefore concluded that humans may reach decisions based on subconscious visual information in a choice reaction task.

  6. Visual Perception Based Rate Control Algorithm for HEVC

    Science.gov (United States)

    Feng, Zeqi; Liu, PengYu; Jia, Kebin

    2018-01-01

    For HEVC, rate control is an indispensably important video coding technology to alleviate the contradiction between video quality and the limited encoding resources during video communication. However, the rate control benchmark algorithm of HEVC ignores subjective visual perception. For key focus regions, bit allocation of LCU is not ideal and subjective quality is unsatisfied. In this paper, a visual perception based rate control algorithm for HEVC is proposed. First bit allocation weight of LCU level is optimized based on the visual perception of luminance and motion to ameliorate video subjective quality. Then λ and QP are adjusted in combination with the bit allocation weight to improve rate distortion performance. Experimental results show that the proposed algorithm reduces average 0.5% BD-BR and maximum 1.09% BD-BR at no cost in bitrate accuracy compared with HEVC (HM15.0). The proposed algorithm devotes to improving video subjective quality under various video applications.

  7. Seeing the sound after visual loss: functional MRI in acquired auditory-visual synesthesia.

    Science.gov (United States)

    Yong, Zixin; Hsieh, Po-Jang; Milea, Dan

    2017-02-01

    Acquired auditory-visual synesthesia (AVS) is a rare neurological sign, in which specific auditory stimulation triggers visual experience. In this study, we used event-related fMRI to explore the brain regions correlated with acquired monocular sound-induced phosphenes, which occurred 2 months after unilateral visual loss due to an ischemic optic neuropathy. During the fMRI session, 1-s pure tones at various pitches were presented to the patient, who was asked to report occurrence of sound-induced phosphenes by pressing one of the two buttons (yes/no). The brain activation during phosphene-experienced trials was contrasted with non-phosphene trials and compared to results obtained in one healthy control subject who underwent the same fMRI protocol. Our results suggest, for the first time, that acquired AVS occurring after visual impairment is associated with bilateral activation of primary and secondary visual cortex, possibly due to cross-wiring between auditory and visual sensory modalities.

  8. Working memory biasing of visual perception without awareness.

    Science.gov (United States)

    Pan, Yi; Lin, Bingyuan; Zhao, Yajun; Soto, David

    2014-10-01

    Previous research has demonstrated that the contents of visual working memory can bias visual processing in favor of matching stimuli in the scene. However, the extent to which such top-down, memory-driven biasing of visual perception is contingent on conscious awareness remains unknown. Here we showed that conscious awareness of critical visual cues is dispensable for working memory to bias perceptual selection mechanisms. Using the procedure of continuous flash suppression, we demonstrated that "unseen" visual stimuli during interocular suppression can gain preferential access to awareness if they match the contents of visual working memory. Strikingly, the very same effect occurred even when the visual cue to be held in memory was rendered nonconscious by masking. Control experiments ruled out the alternative accounts of repetition priming and different detection criteria. We conclude that working memory biases of visual perception can operate in the absence of conscious awareness.

  9. Tools for Teaching Mathematical Functions and Geometric Figures to Tactile Visualization through a Braille Printer for Visual Impairment People

    Directory of Open Access Journals (Sweden)

    Lorena León

    2016-04-01

    Full Text Available In this article, we showed the features and facilities offered by two new computer programs developed for the treatment and generation of geometric figures and math functions, through a Braille printer designed for visually impaired people. The programs have complete accessible features, in which users with full visual impairments can communicate with the systems via short-keys, and the speech synthesizer. The system sends sound messages that will accompanying the user during all the process to generate geometrical figures or to do a mathematical treatment. Finally, a tactile visualization displays as the results to the person with visual impairment, thus they will can complete their geometry and mathematical studies.

  10. Attractive Flicker--Guiding Attention in Dynamic Narrative Visualizations.

    Science.gov (United States)

    Waldner, Manuela; Le Muzic, Mathieu; Bernhard, Matthias; Purgathofer, Werner; Viola, Ivan

    2014-12-01

    Focus+context techniques provide visual guidance in visualizations by giving strong visual prominence to elements of interest while the context is suppressed. However, finding a visual feature to enhance for the focus to pop out from its context in a large dynamic scene, while leading to minimal visual deformation and subjective disturbance, is challenging. This paper proposes Attractive Flicker, a novel technique for visual guidance in dynamic narrative visualizations. We first show that flicker is a strong visual attractor in the entire visual field, without distorting, suppressing, or adding any scene elements. The novel aspect of our Attractive Flicker technique is that it consists of two signal stages: The first "orientation stage" is a short but intensive flicker stimulus to attract the attention to elements of interest. Subsequently, the intensive flicker is reduced to a minimally disturbing luminance oscillation ("engagement stage") as visual support to keep track of the focus elements. To find a good trade-off between attraction effectiveness and subjective annoyance caused by flicker, we conducted two perceptual studies to find suitable signal parameters. We showcase Attractive Flicker with the parameters obtained from the perceptual statistics in a study of molecular interactions. With Attractive Flicker, users were able to easily follow the narrative of the visualization on a large display, while the flickering of focus elements was not disturbing when observing the context.

  11. A noninvasive brain computer interface using visually-induced near-infrared spectroscopy responses.

    Science.gov (United States)

    Chen, Cheng-Hsuan; Ho, Ming-Shan; Shyu, Kuo-Kai; Hsu, Kou-Cheng; Wang, Kuo-Wei; Lee, Po-Lei

    2014-09-19

    Visually-induced near-infrared spectroscopy (NIRS) response was utilized to design a brain computer interface (BCI) system. Four circular checkerboards driven by distinct flickering sequences were displayed on a LCD screen as visual stimuli to induce subjects' NIRS responses. Each flickering sequence was a concatenated sequence of alternative flickering segments and resting segments. The flickering segment was designed with fixed duration of 3s whereas the resting segment was chosen randomly within 15-20s to create the mutual independencies among different flickering sequences. Six subjects were recruited in this study and subjects were requested to gaze at the four visual stimuli one-after-one in a random order. Since visual responses in human brain are time-locked to the onsets of visual stimuli and the flicker sequences of distinct visual stimuli were designed mutually independent, the NIRS responses induced by user's gazed targets can be discerned from non-gazed targets by applying a simple averaging process. The accuracies for the six subjects were higher than 90% after 10 or more epochs being averaged. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. 7 CFR 29.75 - Accessibility of tobacco.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Accessibility of tobacco. 29.75 Section 29.75... REGULATIONS TOBACCO INSPECTION Regulations Mandatory Inspection § 29.75 Accessibility of tobacco. (a) All tobacco subject to mandatory inspection shall be made readily accessible for inspection. (b)(1) Each...

  13. Transient cardio-respiratory responses to visually induced tilt illusions

    Science.gov (United States)

    Wood, S. J.; Ramsdell, C. D.; Mullen, T. J.; Oman, C. M.; Harm, D. L.; Paloski, W. H.

    2000-01-01

    Although the orthostatic cardio-respiratory response is primarily mediated by the baroreflex, studies have shown that vestibular cues also contribute in both humans and animals. We have demonstrated a visually mediated response to illusory tilt in some human subjects. Blood pressure, heart and respiration rate, and lung volume were monitored in 16 supine human subjects during two types of visual stimulation, and compared with responses to real passive whole body tilt from supine to head 80 degrees upright. Visual tilt stimuli consisted of either a static scene from an overhead mirror or constant velocity scene motion along different body axes generated by an ultra-wide dome projection system. Visual vertical cues were initially aligned with the longitudinal body axis. Subjective tilt and self-motion were reported verbally. Although significant changes in cardio-respiratory parameters to illusory tilts could not be demonstrated for the entire group, several subjects showed significant transient decreases in mean blood pressure resembling their initial response to passive head-up tilt. Changes in pulse pressure and a slight elevation in heart rate were noted. These transient responses are consistent with the hypothesis that visual-vestibular input contributes to the initial cardiovascular adjustment to a change in posture in humans. On average the static scene elicited perceived tilt without rotation. Dome scene pitch and yaw elicited perceived tilt and rotation, and dome roll motion elicited perceived rotation without tilt. A significant correlation between the magnitude of physiological and subjective reports could not be demonstrated.

  14. Attentional priorities and access to short-term memory

    DEFF Research Database (Denmark)

    Gillebert, Celine; Dyrholm, Mads; Vangkilde, Signe Allerup

    2012-01-01

    The intraparietal sulcus (IPS) has been implicated in selective attention as well as visual short-term memory (VSTM). To contrast mechanisms of target selection, distracter filtering, and access to VSTM, we combined behavioral testing, computational modeling and functional magnetic resonance......, thereby displaying a significant interaction between the two factors. The interaction between target and distracter set size in IPS could not be accounted for by a simple explanation in terms of number of items accessing VSTM. Instead, it led us to a model where items accessing VSTM receive differential...

  15. Professional Visual Basic 2010 and .NET 4

    CERN Document Server

    Sheldon, Bill; Sharkey, Kent

    2010-01-01

    Intermediate and advanced coverage of Visual Basic 2010 and .NET 4 for professional developers. If you've already covered the basics and want to dive deep into VB and .NET topics that professional programmers use most, this is your book. You'll find a quick review of introductory topics-always helpful-before the author team of experts moves you quickly into such topics as data access with ADO.NET, Language Integrated Query (LINQ), security, ASP.NET web programming with Visual Basic, Windows workflow, threading, and more. You'll explore all the new features of Visual Basic 2010 as well as all t

  16. SCSODC: Integrating Ocean Data for Visualization Sharing and Application

    International Nuclear Information System (INIS)

    Xu, C; Xie, Q; Li, S; Wang, D

    2014-01-01

    The South China Sea Ocean Data Center (SCSODC) was founded in 2010 in order to improve collecting and managing of ocean data of the South China Sea Institute of Oceanology (SCSIO). The mission of SCSODC is to ensure the long term scientific stewardship of ocean data, information and products – collected through research groups, monitoring stations and observation cruises – and to facilitate the efficient use and distribution to possible users. However, data sharing and applications were limited due to the characteristics of distribution and heterogeneity that made it difficult to integrate the data. To surmount those difficulties, the Data Sharing System has been developed by the SCSODC using the most appropriate information management and information technology. The Data Sharing System uses open standards and tools to promote the capability to integrate ocean data and to interact with other data portals or users and includes a full range of processes such as data discovery, evaluation and access combining C/S and B/S mode. It provides a visualized management interface for the data managers and a transparent and seamless data access and application environment for users. Users are allowed to access data using the client software and to access interactive visualization application interface via a web browser. The architecture, key technologies and functionality of the system are discussed briefly in this paper. It is shown that the system of SCSODC is able to implement web visualization sharing and seamless access to ocean data in a distributed and heterogeneous environment

  17. Visual modeling in an analysis of multidimensional data

    Science.gov (United States)

    Zakharova, A. A.; Vekhter, E. V.; Shklyar, A. V.; Pak, A. J.

    2018-01-01

    The article proposes an approach to solve visualization problems and the subsequent analysis of multidimensional data. Requirements to the properties of visual models, which were created to solve analysis problems, are described. As a perspective direction for the development of visual analysis tools for multidimensional and voluminous data, there was suggested an active use of factors of subjective perception and dynamic visualization. Practical results of solving the problem of multidimensional data analysis are shown using the example of a visual model of empirical data on the current state of studying processes of obtaining silicon carbide by an electric arc method. There are several results of solving this problem. At first, an idea of possibilities of determining the strategy for the development of the domain, secondly, the reliability of the published data on this subject, and changes in the areas of attention of researchers over time.

  18. Cortical phase changes measured using 7-T MRI in subjects with subjective cognitive impairment, and their association with cognitive function

    NARCIS (Netherlands)

    Rooden, van Sanneke; Buijs, Mathijs; Vliet, van Marjolein E.; Versluis, Maarten J.; Webb, Andrew G.; Oleksik, Ania M.; Wiel, van de Lotte; Middelkoop, Huub A.M.; Blauw, Gerard Jan; Weverling-Rynsburger, Annelies W.E.; Goos, Jeroen D.C.; Flier, van der Wiesje M.; Koene, Ted; Scheltens, Philip; Barkhof, Frederik; Nieuwerth-van de Rest, Ondine; Slagboom, P.E.; Buchem, van Mark A.; Grond, van der Jeroen

    2016-01-01

    Studies have suggested that, in subjects with subjective cognitive impairment (SCI), Alzheimer's disease (AD)-like changes may occur in the brain. Recently, an in vivo study has indicated the potential of ultra-high-field MRI to visualize amyloid-beta (Aβ)-associated changes in the cortex in

  19. Subjectivities in the Sandbox: Discovering Biases through Visual Memo Writing

    Science.gov (United States)

    Lisi, Bethany

    2016-01-01

    Having insider status at an organization under study can present a researcher with benefits and challenges. Insider researchers may have access to honest dialogue with study participants but may also be vulnerable to uncomfortable conversations and organizational conflicts. Insider researchers also have to contend with their own biases they bring…

  20. Productivity associated with visual status of computer users.

    Science.gov (United States)

    Daum, Kent M; Clore, Katherine A; Simms, Suzanne S; Vesely, Jon W; Wilczek, Dawn D; Spittle, Brian M; Good, Greg W

    2004-01-01

    The aim of this project is to examine the potential connection between the astigmatic refractive corrections of subjects using computers and their productivity and comfort. We hypothesize that improving the visual status of subjects using computers results in greater productivity, as well as improved visual comfort. Inclusion criteria required subjects 19 to 30 years of age with complete vision examinations before being enrolled. Using a double-masked, placebo-controlled, randomized design, subjects completed three experimental tasks calculated to assess the effects of refractive error on productivity (time to completion and the number of errors) at a computer. The tasks resembled those commonly undertaken by computer users and involved visual search tasks of: (1) counties and populations; (2) nonsense word search; and (3) a modified text-editing task. Estimates of productivity for time to completion varied from a minimum of 2.5% upwards to 28.7% with 2 D cylinder miscorrection. Assuming a conservative estimate of an overall 2.5% increase in productivity with appropriate astigmatic refractive correction, our data suggest a favorable cost-benefit ratio of at least 2.3 for the visual correction of an employee (total cost 268 dollars) with a salary of 25,000 dollars per year. We conclude that astigmatic refractive error affected both productivity and visual comfort under the conditions of this experiment. These data also suggest a favorable cost-benefit ratio for employers who provide computer-specific eyewear to their employees.

  1. Crossmodal recruitment of the ventral visual stream in congenital blindness

    DEFF Research Database (Denmark)

    Ptito, Maurice; Matteau, Isabelle; Zhi Wang, Arthur

    2012-01-01

    We used functional MRI (fMRI) to test the hypothesis that blind subjects recruit the ventral visual stream during nonhaptic tactile-form recognition. Congenitally blind and blindfolded sighted control subjects were scanned after they had been trained during four consecutive days to perform......, inferotemporal (IT), cortex, lateral occipital tactile vision area (LOtv), and fusiform gyrus. Control subjects activated area LOtv and precuneus but not cuneus, IT and fusiform gyrus. These results indicate that congenitally blind subjects recruit key regions in the ventral visual pathway during nonhaptic...

  2. Visualization in scientific computing

    National Research Council Canada - National Science Library

    Nielson, Gregory M; Shriver, Bruce D; Rosenblum, Lawrence J

    1990-01-01

    The purpose of this text is to provide a reference source to scientists, engineers, and students who are new to scientific visualization or who are interested in expanding their knowledge in this subject...

  3. Audiovisual correspondence between musical timbre and visual shapes.

    Directory of Open Access Journals (Sweden)

    Mohammad eAdeli

    2014-05-01

    Full Text Available This article investigates the cross-modal correspondences between musical timbre and shapes. Previously, such features as pitch, loudness, light intensity, visual size, and color characteristics have mostly been used in studies of audio-visual correspondences. Moreover, in most studies, simple stimuli e.g. simple tones have been utilized. In this experiment, 23 musical sounds varying in fundamental frequency and timbre but fixed in loudness were used. Each sound was presented once against colored shapes and once against grayscale shapes. Subjects had to select the visual equivalent of a given sound i.e. its shape, color (or grayscale and vertical position. This scenario permitted studying the associations between normalized timbre and visual shapes as well as some of the previous findings for more complex stimuli. 119 subjects (31 females and 88 males participated in the online experiment. Subjects included 36 claimed professional musicians, 47 claimed amateur musicians and 36 claimed non-musicians. 31 subjects have also claimed to have synesthesia-like experiences. A strong association between timbre of envelope normalized sounds and visual shapes was observed. Subjects have strongly associated soft timbres with blue, green or light gray rounded shapes, harsh timbres with red, yellow or dark gray sharp angular shapes and timbres having elements of softness and harshness together with a mixture of the two previous shapes. Color or grayscale had no effect on timbre-shape associations. Fundamental frequency was not associated with height, grayscale or color. The significant correspondence between timbre and shape revealed by the present work allows designing substitution systems which might help the blind to perceive shapes through timbre.

  4. Cell Phones, Tablets, and Other Mobile Technology for Users with Visual Impairments

    Science.gov (United States)

    ... research. Share: Email Print Like (218 Likes) Cell Phones, Tablets, and Other Mobile Technology Touchscreen Smartphone Accessibility for People with Visual Impairments and Blindness The Benefits of Accessible Touchscreen Mobile Devices for People with ...

  5. Flow, affect and visual creativity.

    Science.gov (United States)

    Cseh, Genevieve M; Phillips, Louise H; Pearson, David G

    2015-01-01

    Flow (being in the zone) is purported to have positive consequences in terms of affect and performance; however, there is no empirical evidence about these links in visual creativity. Positive affect often--but inconsistently--facilitates creativity, and both may be linked to experiencing flow. This study aimed to determine relationships between these variables within visual creativity. Participants performed the creative mental synthesis task to simulate the creative process. Affect change (pre- vs. post-task) and flow were measured via questionnaires. The creativity of synthesis drawings was rated objectively and subjectively by judges. Findings empirically demonstrate that flow is related to affect improvement during visual creativity. Affect change was linked to productivity and self-rated creativity, but no other objective or subjective performance measures. Flow was unrelated to all external performance measures but was highly correlated with self-rated creativity; flow may therefore motivate perseverance towards eventual excellence rather than provide direct cognitive enhancement.

  6. Access to Information and Privacy | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    As a Crown corporation, IDRC is subject to Canada's laws on access to information and privacy protection. The following resources will help you learn more about IDRC and the access to information and privacy acts, including instructions for submitting an access to information or privacy act (ATIP) request. IDRC and ATIP ...

  7. Teach yourself visually Office 2013

    CERN Document Server

    Marmel, Elaine

    2013-01-01

    Learn the new Microsoft Office suite the easy, visual way Microsoft Office 2013 is a power-packed suite of office productivity tools including Word, Excel, PowerPoint, Outlook, Access, and Publisher. This easy-to-use visual guide covers the basics of all six programs, with step-by-step instructions and full-color screen shots showing what you should see at each step. You'll also learn about using Office Internet and graphics tools, while the additional examples and advice scattered through the book give you tips on maximizing the Office suite. If you learn best when you can see how

  8. Endpoints of arm movements to visual targets

    NARCIS (Netherlands)

    van den Dobbelsteen, John; Brenner, Eli; Smeets, Jeroen B J

    2001-01-01

    Reaching out for objects with an unseen arm involves using both visual and kinesthetic information. Neither visual nor kinesthetic information is perfect. Each is subject to both constant and variable errors. To evaluate how such errors influence performance in natural goal-directed movements, we

  9. Using eye movement analysis to study auditory effects on visual memory recall.

    Science.gov (United States)

    Marandi, Ramtin Zargari; Sabzpoushan, Seyed Hojjat

    2014-01-01

    Recent studies in affective computing are focused on sensing human cognitive context using biosignals. In this study, electrooculography (EOG) was utilized to investigate memory recall accessibility via eye movement patterns. 12 subjects were participated in our experiment wherein pictures from four categories were presented. Each category contained nine pictures of which three were presented twice and the rest were presented once only. Each picture presentation took five seconds with an adjoining three seconds interval. Similarly, this task was performed with new pictures together with related sounds. The task was free viewing and participants were not informed about the task's purpose. Using pattern recognition techniques, participants' EOG signals in response to repeated and non-repeated pictures were classified for with and without sound stages. The method was validated with eight different participants. Recognition rate in "with sound" stage was significantly reduced as compared with "without sound" stage. The result demonstrated that the familiarity of visual-auditory stimuli can be detected from EOG signals and the auditory input potentially improves the visual recall process.

  10. Using Eye Movement Analysis to Study Auditory Effects on Visual Memory Recall

    Directory of Open Access Journals (Sweden)

    Ramtin Zargari Marandi

    2014-02-01

    Full Text Available Recent studies in affective computing are focused on sensing human cognitive context using biosignals. In this study, electrooculography (EOG was utilized to investigate memory recall accessibility via eye movement patterns. 12 subjects were participated in our experiment wherein pictures from four categories were presented. Each category contained nine pictures of which three were presented twice and the rest were presented once only. Each picture presentation took five seconds with an adjoining three seconds interval. Similarly, this task was performed with new pictures together with related sounds. The task was free viewing and participants were not informed about the task’s purpose. Using pattern recognition techniques, participants’ EOG signals in response to repeated and non-repeated pictures were classified for with and without sound stages. The method was validated with eight different participants. Recognition rate in “with sound” stage was significantly reduced as compared with “without sound” stage. The result demonstrated that the familiarity of visual-auditory stimuli can be detected from EOG signals and the auditory input potentially improves the visual recall process.

  11. Rubber hand illusion under delayed visual feedback.

    Directory of Open Access Journals (Sweden)

    Sotaro Shimada

    Full Text Available BACKGROUND: Rubber hand illusion (RHI is a subject's illusion of the self-ownership of a rubber hand that was touched synchronously with their own hand. Although previous studies have confirmed that this illusion disappears when the rubber hand was touched asynchronously with the subject's hand, the minimum temporal discrepancy of these two events for attenuation of RHI has not been examined. METHODOLOGY/PRINCIPAL FINDINGS: In this study, various temporal discrepancies between visual and tactile stimulations were introduced by using a visual feedback delay experimental setup, and RHI effects in each temporal discrepancy condition were systematically tested. The results showed that subjects felt significantly greater RHI effects with temporal discrepancies of less than 300 ms compared with longer temporal discrepancies. The RHI effects on reaching performance (proprioceptive drift showed similar conditional differences. CONCLUSIONS/SIGNIFICANCE: Our results first demonstrated that a temporal discrepancy of less than 300 ms between visual stimulation of the rubber hand and tactile stimulation to the subject's own hand is preferable to induce strong sensation of RHI. We suggest that the time window of less than 300 ms is critical for multi-sensory integration processes constituting the self-body image.

  12. Timing the impact of literacy on visual processing

    Science.gov (United States)

    Pegado, Felipe; Comerlato, Enio; Ventura, Fabricio; Jobert, Antoinette; Nakamura, Kimihiro; Buiatti, Marco; Ventura, Paulo; Dehaene-Lambertz, Ghislaine; Kolinsky, Régine; Morais, José; Braga, Lucia W.; Cohen, Laurent; Dehaene, Stanislas

    2014-01-01

    Learning to read requires the acquisition of an efficient visual procedure for quickly recognizing fine print. Thus, reading practice could induce a perceptual learning effect in early vision. Using functional magnetic resonance imaging (fMRI) in literate and illiterate adults, we previously demonstrated an impact of reading acquisition on both high- and low-level occipitotemporal visual areas, but could not resolve the time course of these effects. To clarify whether literacy affects early vs. late stages of visual processing, we measured event-related potentials to various categories of visual stimuli in healthy adults with variable levels of literacy, including completely illiterate subjects, early-schooled literate subjects, and subjects who learned to read in adulthood (ex-illiterates). The stimuli included written letter strings forming pseudowords, on which literacy is expected to have a major impact, as well as faces, houses, tools, checkerboards, and false fonts. To evaluate the precision with which these stimuli were encoded, we studied repetition effects by presenting the stimuli in pairs composed of repeated, mirrored, or unrelated pictures from the same category. The results indicate that reading ability is correlated with a broad enhancement of early visual processing, including increased repetition suppression, suggesting better exemplar discrimination, and increased mirror discrimination, as early as ∼100–150 ms in the left occipitotemporal region. These effects were found with letter strings and false fonts, but also were partially generalized to other visual categories. Thus, learning to read affects the magnitude, precision, and invariance of early visual processing. PMID:25422460

  13. Implementing Discretionary Access Control with Time Character in Linux and Performance Analysis

    Institute of Scientific and Technical Information of China (English)

    TAN Liang; ZHOU Ming-Tian

    2006-01-01

    DAC (Discretionary Access Control Policy) is access control based on ownership relations between subject and object, the subject can discretionarily decide on that who, by what methods, can access his owns object. In this paper, the system time is looked as a basic secure element. The DAC_T (Discretionary Access Control Policy with Time Character) is presented and formalized. The DAC_T resolves that the subject can discretionarily decide that who, on when, can access his owns objects. And then the DAC_T is implemented on Linux based on GFAC (General Framework for Access Control), and the algorithm is put forward. Finally, the performance analysis for the DAC_T_Linux is carried out. It is proved that the DAC_T_Linux not only can realize time constraints between subject and object but also can still be accepted by us though its performance have been decreased.

  14. Establishing Visual Category Boundaries between Objects: A PET Study

    Science.gov (United States)

    Saumier, Daniel; Chertkow, Howard; Arguin, Martin; Whatmough, Cristine

    2005-01-01

    Individuals with Alzheimer's disease (AD) often have problems in recognizing common objects. This visual agnosia may stem from difficulties in establishing appropriate visual boundaries between visually similar objects. In support of this hypothesis, Saumier, Arguin, Chertkow, and Renfrew (2001) showed that AD subjects have difficulties in…

  15. Transferring and generalizing deep-learning-based neural encoding models across subjects.

    Science.gov (United States)

    Wen, Haiguang; Shi, Junxing; Chen, Wei; Liu, Zhongming

    2018-08-01

    Recent studies have shown the value of using deep learning models for mapping and characterizing how the brain represents and organizes information for natural vision. However, modeling the relationship between deep learning models and the brain (or encoding models), requires measuring cortical responses to large and diverse sets of natural visual stimuli from single subjects. This requirement limits prior studies to few subjects, making it difficult to generalize findings across subjects or for a population. In this study, we developed new methods to transfer and generalize encoding models across subjects. To train encoding models specific to a target subject, the models trained for other subjects were used as the prior models and were refined efficiently using Bayesian inference with a limited amount of data from the target subject. To train encoding models for a population, the models were progressively trained and updated with incremental data from different subjects. For the proof of principle, we applied these methods to functional magnetic resonance imaging (fMRI) data from three subjects watching tens of hours of naturalistic videos, while a deep residual neural network driven by image recognition was used to model visual cortical processing. Results demonstrate that the methods developed herein provide an efficient and effective strategy to establish both subject-specific and population-wide predictive models of cortical representations of high-dimensional and hierarchical visual features. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Fast visual prediction and slow optimization of preferred walking speed.

    Science.gov (United States)

    O'Connor, Shawn M; Donelan, J Maxwell

    2012-05-01

    People prefer walking speeds that minimize energetic cost. This may be accomplished by directly sensing metabolic rate and adapting gait to minimize it, but only slowly due to the compounded effects of sensing delays and iterative convergence. Visual and other sensory information is available more rapidly and could help predict which gait changes reduce energetic cost, but only approximately because it relies on prior experience and an indirect means to achieve economy. We used virtual reality to manipulate visually presented speed while 10 healthy subjects freely walked on a self-paced treadmill to test whether the nervous system beneficially combines these two mechanisms. Rather than manipulating the speed of visual flow directly, we coupled it to the walking speed selected by the subject and then manipulated the ratio between these two speeds. We then quantified the dynamics of walking speed adjustments in response to perturbations of the visual speed. For step changes in visual speed, subjects responded with rapid speed adjustments (lasting 300 s). The timing and direction of these responses strongly indicate that a rapid predictive process informed by visual feedback helps select preferred speed, perhaps to complement a slower optimization process that seeks to minimize energetic cost.

  17. Dynamic visualizations as tools for supporting cosmological literacy

    Science.gov (United States)

    Buck, Zoe Elizabeth

    My dissertation research is designed to improve access to STEM content through the development of cosmology visualizations that support all learners as they engage in cosmological sense-making. To better understand how to design visualizations that work toward breaking cycles of power and access in the sciences, I orient my work to following "meta-question": How might educators use visualizations to support diverse ways of knowing and learning in order to expand access to cosmology, and to science? In this dissertation, I address this meta-question from a pragmatic epistemological perspective, through a sociocultural lens, following three lines of inquiry: experimental methods (Creswell, 2003) with a focus on basic visualization design, activity analysis (Wells, 1996; Ash, 2001; Rahm, 2012) with a focus on culturally and linguistically diverse learners, and case study (Creswell, 2000) with a focus on expansive learning at a planetarium (Engestrom, 2001; Ash, 2014). My research questions are as follows, each of which corresponds to a self contained course of inquiry with its own design, data, analysis and results: 1) Can mediational cues like color affect the way learners interpret the content in a cosmology visualization? 2) How do cosmology visualizations support cosmological sense-making for diverse students? 3) What are the shared objects of dynamic networks of activity around visualization production and use in a large, urban planetarium and how do they affect learning? The result is a mixed-methods design (Sweetman, Badiee & Creswell, 2010) where both qualitative and quantitative data are used when appropriate to address my research goals. In the introduction I begin by establishing a theoretical framework for understanding visualizations within cultural historical activity theory (CHAT) and situating the chapters that follow within that framework. I also introduce the concept of cosmological literacy, which I define as the set of conceptual, semiotic and

  18. Visual communication and the content and style of conversation.

    Science.gov (United States)

    Rutter, D R; Stephenson, G M; Dewey, M E

    1981-02-01

    Previous research suggests that visual communication plays a number of important roles in social interaction. In particular, it appears to influence the content of what people say in discussions, the style of their speech, and the outcomes they reach. However, the findings are based exclusively on comparisons between face-to-face conversations and audio conversations, in which subjects sit in separate rooms and speak over a microphone-headphone intercom which precludes visual communication. Interpretation is difficult, because visual communication is confounded with physical presence, which itself makes available certain cues denied to audio subjects. The purpose of this paper is to report two experiments in which the variables were separated and content and style were re-examined. The first made use of blind subjects, and again compared the face-to-face and audio conditions. The second returned to sighted subjects, and examined four experimental conditions: face-to-face; audio; a curtain condition in which subjects sat in the same room but without visual communication; and a video condition in which they sat in separate rooms and communicated over a television link. Neither visual communication nor physical presence proved to be critical variable. Instead, the two sources of cues combined, such that content and style were influenced by the aggregate of available cues. The more cueless the settings, the more task-oriented, depersonalized and unspontaneous the conversation. The findings also suggested that the primary effect of cuelessness is to influence verbal content, and that its influence on both style and outcome occurs indirectly, through the mediation of content.

  19. Gaze strategies during visually-guided versus memory-guided grasping.

    Science.gov (United States)

    Prime, Steven L; Marotta, Jonathan J

    2013-03-01

    Vision plays a crucial role in guiding motor actions. But sometimes we cannot use vision and must rely on our memory to guide action-e.g. remembering where we placed our eyeglasses on the bedside table when reaching for them with the lights off. Recent studies show subjects look towards the index finger grasp position during visually-guided precision grasping. But, where do people look during memory-guided grasping? Here, we explored the gaze behaviour of subjects as they grasped a centrally placed symmetrical block under open- and closed-loop conditions. In Experiment 1, subjects performed grasps in either a visually-guided task or memory-guided task. The results show that during visually-guided grasping, gaze was first directed towards the index finger's grasp point on the block, suggesting gaze targets future grasp points during the planning of the grasp. Gaze during memory-guided grasping was aimed closer to the blocks' centre of mass from block presentation to the completion of the grasp. In Experiment 2, subjects performed an 'immediate grasping' task in which vision of the block was removed immediately at the onset of the reach. Similar to the visually-guided results from Experiment 1, gaze was primarily directed towards the index finger location. These results support the 2-stream theory of vision in that motor planning with visual feedback at the onset of the movement is driven primarily by real-time visuomotor computations of the dorsal stream, whereas grasping remembered objects without visual feedback is driven primarily by the perceptual memory representations mediated by the ventral stream.

  20. The relationship between better-eye and integrated visual field mean deviation and visual disability.

    Science.gov (United States)

    Arora, Karun S; Boland, Michael V; Friedman, David S; Jefferys, Joan L; West, Sheila K; Ramulu, Pradeep Y

    2013-12-01

    To determine the extent of difference between better-eye visual field (VF) mean deviation (MD) and integrated VF (IVF) MD among Salisbury Eye Evaluation (SEE) subjects and a larger group of glaucoma clinic subjects and to assess how those measures relate to objective and subjective measures of ability/performance in SEE subjects. Retrospective analysis of population- and clinic-based samples of adults. A total of 490 SEE and 7053 glaucoma clinic subjects with VF loss (MD ≤-3 decibels [dB] in at least 1 eye). Visual field testing was performed in each eye, and IVF MD was calculated. Differences between better-eye and IVF MD were calculated for SEE and clinic-based subjects. In SEE subjects with VF loss, models were constructed to compare the relative impact of better-eye and IVF MD on driving habits, mobility, self-reported vision-related function, and reading speed. Difference between better-eye and IVF MD and relationship of better-eye and IVF MD with performance measures. The median difference between better-eye and IVF MD was 0.41 dB (interquartile range [IQR], -0.21 to 1.04 dB) and 0.72 dB (IQR, 0.04-1.45 dB) for SEE subjects and clinic-based patients with glaucoma, respectively, with differences of ≥ 2 dB between the 2 MDs observed in 9% and 18% of the groups, respectively. Among SEE subjects with VF loss, both MDs demonstrated similar associations with multiple ability and performance metrics as judged by the presence/absence of a statistically significant association between the MD and the metric, the magnitude of observed associations (odds ratios, rate ratios, or regression coefficients associated with 5-dB decrements in MD), and the extent of variability in the metric explained by the model (R(2)). Similar associations of similar magnitude also were noted for the subgroup of subjects with glaucoma and subjects in whom better-eye and IVF MD differed by ≥ 2 dB. The IVF MD rarely differs from better-eye MD, and similar associations between VF loss and

  1. BrainBrowser: distributed, web-based neurological data visualization

    Directory of Open Access Journals (Sweden)

    Tarek eSherif

    2015-01-01

    Full Text Available Recent years have seen massive, distributed datasets become the norm in neuroimaging research, and the methodologies used analyze them have, in response, become more collaborative and exploratory. Tools and infrastructure are continuously being developed and deployed to facilitate research in this context: grid computation platforms to process the data, distributed data stores to house and share them, high-speed networks to move them around and collaborative, often web-based, platforms to provide access to and sometimes manage the entire system. BrainBrowser is a lightweight, high-performance JavaScript visualization library built to provide easy-to-use, powerful, on-demand visualization of remote datasets in this new research environment. BrainBrowser leverages modern Web technologies, such as WebGL, HTML5 and Web Workers, to visualize 3D surface and volumetric neuroimaging data in any modern web browser without requiring any browser plugins. It is thus trivial to integrate BrainBrowser into any web-based platform. BrainBrowser is simple enough to produce a basic web-based visualization in a few lines of code, while at the same time being robust enough to create full-featured visualization applications. BrainBrowser can dynamically load the data required for a given visualization, so no network bandwidth needs to be waisted on data that will not be used. BrainBrowser's integration into the standardized web platform also allows users to consider using 3D data visualization in novel ways, such as for data distribution, data sharing and dynamic online publications. BrainBrowser is already being used in two major online platforms, CBRAIN and LORIS, and has been used to make the 1TB MACACC dataset openly accessible.

  2. Visual input that matches the content of vist of visual working memory requires less (not faster) evidence sampling to reach conscious access

    NARCIS (Netherlands)

    Gayet, S.; van Maanen, L.; Heilbron, M.; Paffen, C.L.E.; Van Der Stigchel, S.

    2016-01-01

    The content of visual working memory (VWM) affects the processing of concurrent visual input. Recently, it has been demonstrated that stimuli are released from interocular suppression faster when they match rather than mismatch a color that is memorized for subsequent recall. In order to investigate

  3. Near-infrared vascular imaging in peripheral venous and arterial access

    OpenAIRE

    Cuper, N.J.

    2012-01-01

    Venous and arterial access are among the most widespread medical procedures performed in children. Especially in young children venous and arterial access can be problematic due to tiny blood vessels that are difficult to localize beneath a layer of baby fat. This thesis describes the development and clinical evaluation of the VascuLuminator, a guidance tool for peripheral venous and arterial access by visualizing blood vessels underneath the skin with near-infrared light. In a third to a fif...

  4. Applying Pragmatics Principles for Interaction with Visual Analytics.

    Science.gov (United States)

    Hoque, Enamul; Setlur, Vidya; Tory, Melanie; Dykeman, Isaac

    2018-01-01

    Interactive visual data analysis is most productive when users can focus on answering the questions they have about their data, rather than focusing on how to operate the interface to the analysis tool. One viable approach to engaging users in interactive conversations with their data is a natural language interface to visualizations. These interfaces have the potential to be both more expressive and more accessible than other interaction paradigms. We explore how principles from language pragmatics can be applied to the flow of visual analytical conversations, using natural language as an input modality. We evaluate the effectiveness of pragmatics support in our system Evizeon, and present design considerations for conversation interfaces to visual analytics tools.

  5. 9 CFR 590.132 - Access to plants.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Access to plants. 590.132 Section 590... Service § 590.132 Access to plants. Access shall not be refused to any representative of the Secretary to any plant, place of business, or transport vehicle subject to inspection under the provisions of this...

  6. Subjective visual horizontal during follow-up after unilateral vestibular deafferentation with gentamicin.

    Science.gov (United States)

    Tribukait, A; Bergenius, J; Brantberg, K

    1998-07-01

    The subjective visual horizontal (SVH) was measured by means of a small, rotatable, luminous line in darkness in the upright head and body position and at 10, 20 and 30 degrees of tilt to the right and left before, and repeatedly during a follow-up period of 1 year after intratympanic gentamicin instillations in 12 patients with recurrent vertigo attacks. This treatment caused a loss of the bithermal caloric responses on the diseased side. Shortly after treatment there was a significant tilt of SVH towards the treated side (group mean = 10.6 degrees). Repeated testing made it possible to characterize mathematically the changes with time for SVH. For the group of patients as a whole this otolithic component of vestibular compensation was best described by a power function, SVH = 8.65t(-0.16) degrees, where t is time in days after maximum tilt of SVH. After 1 year, SVH was still significantly tilted towards the treated side (group mean = 3.16 degrees). Gentamicin treatment also caused a significant reduction in the perception of head and body tilt towards the deafferented side, while the perception of tilt towards the healthy side did not show any significant changes. During follow-up there was a gradual improvement in the perception of tilt towards the treated side. However, a significant asymmetry in roll-tilt perception was still present 1 year after deafferentation. There was no correlation between SVH in the upright position and roll-tilt perception, suggesting that these parameters are to some extent dependent on different afferent input from the vestibular organ. They were also found to be complementary for the detection of vestibular disturbance.

  7. LTP-like plasticity in the visual system and in the motor system appear related in young and healthy subjects

    Directory of Open Access Journals (Sweden)

    Stefan eKlöppel

    2015-09-01

    Full Text Available LTP-like plasticity measured by visual evoked potentials (VEP can be induced in the intact human brain by presenting checkerboard reversals. Also associated with LTP-like plasticity, around two third of participants respond to transcranial magnetic stimulation with a paired-associate stimulation (PAS protocol with a potentiation of their motor evoked potentials. LTP-like processes are also required for verbal and motor learning tasks. We compared effect sizes, responder rates and intercorrelations as well as the potential influence of attention between these four assessments in a group of 37 young and healthy volunteers. We observed a potentiation effect of the N75 and P100 VEP component which positively correlated with plasticity induced by PAS. Subjects with a better subjective alertness were more likely to show PAS and VEP potentiation. No correlation was found between the other assessments. Effect sizes and responder rates of VEP potentiation were higher compared to PAS. Our results indicate a high variability of LTP-like effects and no evidence for a system-specific nature. As a consequence, studies wishing to assess individual levels of LTP-like plasticity should employ a combination of multiple assessments.

  8. On the Matching of Seen and Felt Shape by Newly Sighted Subjects

    Directory of Open Access Journals (Sweden)

    John Schwenkler

    2012-04-01

    Full Text Available How do we recognize identities between seen shapes and felt ones? Is this due to associative learning, or intrinsic connections these sensory modalities? We can address this question by testing the capacities of newly sighted subjects to match seen and felt shapes, but only if the subjects can see the objects well enough to form adequate visual representations of their shapes. In light of this, a recent study by R. Held and colleagues fails to demonstrate that their newly sighted subjects' inability to match seen and felt shape was due to a lack of intermodal connections rather than a purely visual deficit, as the subjects may not have been able visually to represent 3D shape in the perspective-invariant manner required for intermodal matching. However, the study could be modified in any of several ways to help avoid this problem.

  9. [Associative visual agnosia. The less visible consequences of a cerebral infarction].

    Science.gov (United States)

    Diesfeldt, H F A

    2011-02-01

    After a cerebral infarction, some patients acutely demonstrate contralateral hemiplegia, or aphasia. Those are the obvious symptoms of a cerebral infarction. However, less visible but burdensome consequences may go unnoticed without closer investigation. The importance of a thorough clinical examination is exemplified by a single case study of a 72-year-old, right-handed male. Two years before he had suffered from an ischemic stroke in the territory of the left posterior cerebral artery, with right homonymous hemianopia and global alexia (i.e., impairment in letter recognition and profound impairment of reading) without agraphia. Naming was impaired on visual presentation (20%-39% correct), but improved significantly after tactile presentation (87% correct) or verbal definition (89%). Pre-semantic visual processing was normal (correct matching of different views of the same object), as was his access to structural knowledge from vision (he reliably distinguished real objects from non-objects). On a colour decision task he reliably indicated which of two items was coloured correctly. Though he was unable to mime how visually presented objects were used, he more reliably matched pictures of objects with pictures of a mime artist gesturing the use of the object. He obtained normal scores on word definition (WAIS-III), synonym judgment and word-picture matching tasks with perceptual and semantic distractors. He however failed when he had to match physically dissimilar specimens of the same object or when he had to decide which two of five objects were related associatively (Pyramids and Palm Trees Test). The patient thus showed a striking contrast in his intact ability to access knowledge of object shape or colour from vision and impaired functional and associative knowledge. As a result, he could not access a complete semantic representation, required for activating phonological representations to name visually presented objects. The pattern of impairments and

  10. Principles of visual attention

    DEFF Research Database (Denmark)

    Bundesen, Claus; Habekost, Thomas

    research as a field that is fundamentally fragmented. This book takes a different perspective and presents a unified theory of visual attention: the TVA model. The TVA model explains the many aspects of visual attention by just two mechanisms for selection of information: filtering and pigeonholing......The nature of attention is one of the oldest and most central problems in psychology. A huge amount of research has been produced on this subject in the last half century, especially on attention in the visual modality, but a general explanation has remained elusive. Many still view attention....... These mechanisms are described in a set of simple equations, which allow TVA to mathematically model a large number of classical results in the attention literature. The theory explains psychological and neuroscientific findings by the same equations; TVA is a complete theory of visual attention, linking mind...

  11. Developing Visual Thinking in the Electronic Health Record.

    Science.gov (United States)

    Boyd, Andrew D; Young, Christine D; Amatayakul, Margret; Dieter, Michael G; Pawola, Lawrence M

    2017-01-01

    The purpose of this vision paper is to identify how data visualization could transform healthcare. Electronic Health Records (EHRs) are maturing with new technology and tools being applied. Researchers are reaping the benefits of data visualization to better access compilations of EHR data for enhanced clinical research. Data visualization, while still primarily the domain of clinical researchers, is beginning to show promise for other stakeholders. A non-exhaustive review of the literature indicates that respective to the growth and development of the EHR, the maturity of data visualization in healthcare is in its infancy. Visual analytics has been only cursorily applied to healthcare. A fundamental issue contributing to fragmentation and poor coordination of healthcare delivery is that each member of the healthcare team, including patients, has a different view. Summarizing all of this care comprehensively for any member of the healthcare team is a "wickedly hard" visual analytics and data visualization problem to solve.

  12. Alzheimer disease: functional abnormalities in the dorsal visual pathway.

    LENUS (Irish Health Repository)

    Bokde, Arun L W

    2012-02-01

    PURPOSE: To evaluate whether patients with Alzheimer disease (AD) have altered activation compared with age-matched healthy control (HC) subjects during a task that typically recruits the dorsal visual pathway. MATERIALS AND METHODS: The study was performed in accordance with the Declaration of Helsinki, with institutional ethics committee approval, and all subjects provided written informed consent. Two tasks were performed to investigate neural function: face matching and location matching. Twelve patients with mild AD and 14 age-matched HC subjects were included. Brain activation was measured by using functional magnetic resonance imaging. Group statistical analyses were based on a mixed-effects model corrected for multiple comparisons. RESULTS: Task performance was not statistically different between the two groups, and within groups there were no differences in task performance. In the HC group, the visual perception tasks selectively activated the visual pathways. Conversely in the AD group, there was no selective activation during performance of these same tasks. Along the dorsal visual pathway, the AD group recruited additional regions, primarily in the parietal and frontal lobes, for the location-matching task. There were no differences in activation between groups during the face-matching task. CONCLUSION: The increased activation in the AD group may represent a compensatory mechanism for decreased processing effectiveness in early visual areas of patients with AD. The findings support the idea that the dorsal visual pathway is more susceptible to putative AD-related neuropathologic changes than is the ventral visual pathway.

  13. Checklist of accessibility in Web informational environments

    Directory of Open Access Journals (Sweden)

    Christiane Gomes dos Santos

    2017-01-01

    Full Text Available This research deals with the process of search, navigation and retrieval of information by the person with blindness in web environment, focusing on knowledge of the areas of information recovery and architecture, to understanding the strategies used by these people to access the information on the web. It aims to propose the construction of an accessibility verification instrument, checklist, to be used to analyze the behavior of people with blindness in search actions, navigation and recovery sites and pages. It a research exploratory and descriptive of qualitative nature, with the research methodology, case study - the research to establish a specific study with the simulation of search, navigation and information retrieval using speech synthesis system, NonVisual Desktop Access, in assistive technologies laboratory, to substantiate the construction of the checklist for accessibility verification. It is considered the reliability of performed research and its importance for the evaluation of accessibility in web environment to improve the access of information for people with limited reading in order to be used on websites and pages accessibility check analysis.

  14. CRAVE: a database, middleware and visualization system for phenotype ontologies.

    Science.gov (United States)

    Gkoutos, Georgios V; Green, Eain C J; Greenaway, Simon; Blake, Andrew; Mallon, Ann-Marie; Hancock, John M

    2005-04-01

    A major challenge in modern biology is to link genome sequence information to organismal function. In many organisms this is being done by characterizing phenotypes resulting from mutations. Efficiently expressing phenotypic information requires combinatorial use of ontologies. However tools are not currently available to visualize combinations of ontologies. Here we describe CRAVE (Concept Relation Assay Value Explorer), a package allowing storage, active updating and visualization of multiple ontologies. CRAVE is a web-accessible JAVA application that accesses an underlying MySQL database of ontologies via a JAVA persistent middleware layer (Chameleon). This maps the database tables into discrete JAVA classes and creates memory resident, interlinked objects corresponding to the ontology data. These JAVA objects are accessed via calls through the middleware's application programming interface. CRAVE allows simultaneous display and linking of multiple ontologies and searching using Boolean and advanced searches.

  15. [Effects of construct accessibility and self-schema on person memory].

    Science.gov (United States)

    Kitamura, H

    1991-10-01

    The present study investigated the relationship among construct accessibility, self-schema and person memory. Three hundred and thirty-four subjects received 40 behavioral descriptions of a stimulus person, consisting of eight specific behaviors on each of five trait-dimensions. Subjects also rated personality traits of their acquaintances and themselves on nine-point bipolar scales and ranked the importance of the five trait-dimensions. Weights, which subjects assigned to each of the five dimensions, were calculated as indices of construct accessibility. Self-schema scores of each subject were also calculated based on his/her ratings. Multiple regression analyses indicated that the dimensional weights and self-schema scores were positively correlated with the recall performance of the descriptions of the stimulus person. The schematics recalled significantly more descriptions than the aschematics, whether their self-schema was positive or negative. Subjects who had positive self-schema showed higher construct accessibility than the aschematics. It was argued that the relationship between construct accessibility and self-schema might be affected by motivational factors such as self-esteem.

  16. Visual search is modulated by action intentions

    NARCIS (Netherlands)

    Bekkering, H; Neggers, SFW

    The influence of action intentions on visual selection processes was investigated in a visual search paradigm. A predefined target object with a certain orientation and color was presented among distractors, and subjects had to either look and point at the target or look at and grasp the target.

  17. Motor Training: Comparison of Visual and Auditory Coded Proprioceptive Cues

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    Philip Jepson

    2012-05-01

    Full Text Available Self-perception of body posture and movement is achieved through multi-sensory integration, particularly the utilisation of vision, and proprioceptive information derived from muscles and joints. Disruption to these processes can occur following a neurological accident, such as stroke, leading to sensory and physical impairment. Rehabilitation can be helped through use of augmented visual and auditory biofeedback to stimulate neuro-plasticity, but the effective design and application of feedback, particularly in the auditory domain, is non-trivial. Simple auditory feedback was tested by comparing the stepping accuracy of normal subjects when given a visual spatial target (step length and an auditory temporal target (step duration. A baseline measurement of step length and duration was taken using optical motion capture. Subjects (n=20 took 20 ‘training’ steps (baseline ±25% using either an auditory target (950 Hz tone, bell-shaped gain envelope or visual target (spot marked on the floor and were then asked to replicate the target step (length or duration corresponding to training with all feedback removed. Visual cues (mean percentage error=11.5%; SD ± 7.0%; auditory cues (mean percentage error = 12.9%; SD ± 11.8%. Visual cues elicit a high degree of accuracy both in training and follow-up un-cued tasks; despite the novelty of the auditory cues present for subjects, the mean accuracy of subjects approached that for visual cues, and initial results suggest a limited amount of practice using auditory cues can improve performance.

  18. Quantifying space, understanding minds: A visual summary approach

    Directory of Open Access Journals (Sweden)

    Mark Simpson

    2017-06-01

    Full Text Available This paper presents an illustrated, validated taxonomy of research that compares spatial measures to human behavior. Spatial measures quantify the spatial characteristics of environments, such as the centrality of intersections in a street network or the accessibility of a room in a building from all the other rooms. While spatial measures have been of interest to spatial sciences, they are also of importance in the behavioral sciences for use in modeling human behavior. A high correlation between values for spatial measures and specific behaviors can provide insights into an environment's legibility, and contribute to a deeper understanding of human spatial cognition. Research in this area takes place in several domains, which makes a full understanding of existing literature difficult. To address this challenge, we adopt a visual summary approach. Literature is analyzed, and recurring topics are identified and validated with independent inter-rater agreement tasks in order to create a robust taxonomy for spatial measures and human behavior. The taxonomy is then illustrated with a visual representation that allows for at-a-glance visual access to the content of individual research papers in a corpus. A public web interface has been created that allows interested researchers to add to the database and create visual summaries for their research papers using our taxonomy.

  19. The spatiotopic 'visual' cortex of the blind

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    Likova, Lora

    2012-03-01

    Visual cortex activity in the blind has been shown in sensory tasks. Can it be activated in memory tasks? If so, are inherent features of its organization meaningfully employed? Our recent results in short-term blindfolded subjects imply that human primary visual cortex (V1) may operate as a modality-independent 'sketchpad' for working memory (Likova, 2010a). Interestingly, the spread of the V1 activation approximately corresponded to the spatial extent of the images in terms of their angle of projection to the subject. We now raise the questions of whether under long-term visual deprivation V1 is also employed in non-visual memory task, in particular in congenitally blind individuals, who have never had visual stimulation to guide the development of the visual area organization, and whether such spatial organization is still valid for the same paradigm that was used in blindfolded individuals. The outcome has implications for an emerging reconceptualization of the principles of brain architecture and its reorganization under sensory deprivation. Methods: We used a novel fMRI drawing paradigm in congenitally and late-onset blind, compared with sighted and blindfolded subjects in three conditions of 20s duration, separated by 20s rest-intervals, (i) Tactile Exploration: raised-line images explored and memorized; (ii) Tactile Memory Drawing: drawing the explored image from memory; (iii) Scribble: mindless drawing movements with no memory component. Results and Conclusions: V1 was strongly activated for Tactile Memory Drawing and Tactile Exploration in these totally blind subjects. Remarkably, after training, even in the memory task, the mapping of V1 activation largely corresponded to the angular projection of the tactile stimuli relative to the ego-center (i.e., the effective visual angle at the head); beyond this projective boundary, peripheral V1 signals were dramatically reduced or even suppressed. The matching extent of the activation in the congenitally blind

  20. Making Time for Nature: Visual Exposure to Natural Environments Lengthens Subjective Time Perception and Reduces Impulsivity.

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    Meredith S Berry

    Full Text Available Impulsivity in delay discounting is associated with maladaptive behaviors such as overeating and drug and alcohol abuse. Researchers have recently noted that delay discounting, even when measured by a brief laboratory task, may be the best predictor of human health related behaviors (e.g., exercise currently available. Identifying techniques to decrease impulsivity in delay discounting, therefore, could help improve decision-making on a global scale. Visual exposure to natural environments is one recent approach shown to decrease impulsive decision-making in a delay discounting task, although the mechanism driving this result is currently unknown. The present experiment was thus designed to evaluate not only whether visual exposure to natural (mountains, lakes relative to built (buildings, cities environments resulted in less impulsivity, but also whether this exposure influenced time perception. Participants were randomly assigned to either a natural environment condition or a built environment condition. Participants viewed photographs of either natural scenes or built scenes before and during a delay discounting task in which they made choices about receiving immediate or delayed hypothetical monetary outcomes. Participants also completed an interval bisection task in which natural or built stimuli were judged as relatively longer or shorter presentation durations. Following the delay discounting and interval bisection tasks, additional measures of time perception were administered, including how many minutes participants thought had passed during the session and a scale measurement of whether time "flew" or "dragged" during the session. Participants exposed to natural as opposed to built scenes were less impulsive and also reported longer subjective session times, although no differences across groups were revealed with the interval bisection task. These results are the first to suggest that decreased impulsivity from exposure to natural as

  1. The prevalence and causes of visual impairment and blindness among older adults in the city of Lodz, Poland.

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    Nowak, Michal S; Smigielski, Janusz

    2015-02-01

    To investigate the prevalence and causes of visual impairment and blindness in a sample of Polish older adults. The study was designed in a cross-sectional and observational manner. Data concerning the vision status were assessed in 2214 eyes from 1107 subjects of European Caucasian origin; most of whom live in the city of Lodz, in central Poland. Visual impairment was defined as distance visual acuity visual acuity (BCVA) 20/200 in better-seeing eye, and blindness was defined as BCVA ≤20/200 in both eyes (United States criteria). Visual impairment was found in 27.5% subjects in the worse-seeing eye. Multiple regression analysis showed that increasing age (OR 0.98, 95% CI 0.97-0.99) and female gender (OR 1.47, 95% CI 1.11-1.93) were independent risk factors. No association was found between visual impairment and socioeconomic status of subjects. Noncorrectable visual impairment was found in 7.0% of subjects, including 5.2% of subjects with unilateral and 1.8% of subjects with bilateral visual impairment. Low vision and blindness accounted for 1.3% and 0.5%, respectively, and were only associated with older age (OR 1.05, 95% CI 1.02-1.10). Retinal diseases represented the major cause of noncorrectable visual impairment and accounted for more than half of causes of blindness. Provision of appropriate refractive correction improves visual acuity in 75% subjects presenting with visual impairment. Retinal diseases are a major cause of noncorrectable visual impairment and blindness in this older population.

  2. Working Memory Processing In Normal Subjects and Subjects with Dyslexia

    Science.gov (United States)

    Bowyer, S. M.; Lajiness-O'Neill, R.; Weiland, B. J.; Mason, K.; Tepley, N.

    2004-10-01

    Magnetoencephalography (MEG) was used to determine the neuroanatomical location of working memory (WM) processes. Differences between subjects with dyslexia (SD; n=5) and normal readers (NR; n=5) were studied during two WM tasks. A spatial WM task (SMW) consisted of blocks visually presented in one of 12 positions for 2 s each. Subjects were to determine if the current position matched the position presented 2 slides earlier (N-Back Test). The verbal task (VMW) consisted of presentation of a single letter. The location of cortical activity during SWM in NR (determined with MR-FOCUSS analysis) was in the right superior temporal gyrus (STG) and right angular gyrus (AG). Similar activation was seen in SD with a slight delay of approximately 20 ms. During VWM activity was seen in LEFT STG and LEFT AG in NR. In contrast for SD, activation was in the RIGHT STG and RIGHT AG. This study demonstrates the possibility to differentiate WM processing in subjects with and without learning disorders.

  3. Is theta burst stimulation applied to visual cortex able to modulate peripheral visual acuity?

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    Sabrina Brückner

    Full Text Available Repetitive transcranial magnetic stimulation is usually applied to visual cortex to explore the effects on cortical excitability. Most researchers therefore concentrate on changes of phosphene threshold, rarely on consequences for visual performance. Thus, we investigated peripheral visual acuity in the four quadrants of the visual field using Landolt C optotypes before and after repetitive stimulation of the visual cortex. We applied continuous and intermittend theta burst stimulation with various stimulation intensities (60%, 80%, 100%, 120% of individual phosphene threshold as well as monophasic and biphasic 1 Hz stimulation, respectively. As an important result, no serious adverse effects were observed. In particular, no seizure was induced, even with theta burst stimulation applied with 120% of individual phosphene threshold. In only one case stimulation was ceased because the subject reported intolerable pain. Baseline visual acuity decreased over sessions, indicating a continuous training effect. Unexpectedly, none of the applied transcranial magnetic stimulation protocols had an effect on performance: no change in visual acuity was found in any of the four quadrants of the visual field. Binocular viewing as well as the use of peripheral instead of foveal presentation of the stimuli might have contributed to this result. Furthermore, intraindividual variability could have masked the TMS- induced effects on visual acuity.

  4. Indoor Spatial Updating with Reduced Visual Information.

    Science.gov (United States)

    Legge, Gordon E; Gage, Rachel; Baek, Yihwa; Bochsler, Tiana M

    2016-01-01

    Spatial updating refers to the ability to keep track of position and orientation while moving through an environment. People with impaired vision may be less accurate in spatial updating with adverse consequences for indoor navigation. In this study, we asked how artificial restrictions on visual acuity and field size affect spatial updating, and also judgments of the size of rooms. Normally sighted young adults were tested with artificial restriction of acuity in Mild Blur (Snellen 20/135) and Severe Blur (Snellen 20/900) conditions, and a Narrow Field (8°) condition. The subjects estimated the dimensions of seven rectangular rooms with and without these visual restrictions. They were also guided along three-segment paths in the rooms. At the end of each path, they were asked to estimate the distance and direction to the starting location. In Experiment 1, the subjects walked along the path. In Experiment 2, they were pushed in a wheelchair to determine if reduced proprioceptive input would result in poorer spatial updating. With unrestricted vision, mean Weber fractions for room-size estimates were near 20%. Severe Blur but not Mild Blur yielded larger errors in room-size judgments. The Narrow Field was associated with increased error, but less than with Severe Blur. There was no effect of visual restriction on estimates of distance back to the starting location, and only Severe Blur yielded larger errors in the direction estimates. Contrary to expectation, the wheelchair subjects did not exhibit poorer updating performance than the walking subjects, nor did they show greater dependence on visual condition. If our results generalize to people with low vision, severe deficits in acuity or field will adversely affect the ability to judge the size of indoor spaces, but updating of position and orientation may be less affected by visual impairment.

  5. Indoor Spatial Updating with Reduced Visual Information.

    Directory of Open Access Journals (Sweden)

    Gordon E Legge

    Full Text Available Spatial updating refers to the ability to keep track of position and orientation while moving through an environment. People with impaired vision may be less accurate in spatial updating with adverse consequences for indoor navigation. In this study, we asked how artificial restrictions on visual acuity and field size affect spatial updating, and also judgments of the size of rooms.Normally sighted young adults were tested with artificial restriction of acuity in Mild Blur (Snellen 20/135 and Severe Blur (Snellen 20/900 conditions, and a Narrow Field (8° condition. The subjects estimated the dimensions of seven rectangular rooms with and without these visual restrictions. They were also guided along three-segment paths in the rooms. At the end of each path, they were asked to estimate the distance and direction to the starting location. In Experiment 1, the subjects walked along the path. In Experiment 2, they were pushed in a wheelchair to determine if reduced proprioceptive input would result in poorer spatial updating.With unrestricted vision, mean Weber fractions for room-size estimates were near 20%. Severe Blur but not Mild Blur yielded larger errors in room-size judgments. The Narrow Field was associated with increased error, but less than with Severe Blur. There was no effect of visual restriction on estimates of distance back to the starting location, and only Severe Blur yielded larger errors in the direction estimates. Contrary to expectation, the wheelchair subjects did not exhibit poorer updating performance than the walking subjects, nor did they show greater dependence on visual condition.If our results generalize to people with low vision, severe deficits in acuity or field will adversely affect the ability to judge the size of indoor spaces, but updating of position and orientation may be less affected by visual impairment.

  6. Visual search of illusory contours: Shape and orientation effects

    Directory of Open Access Journals (Sweden)

    Gvozdenović Vasilije

    2008-01-01

    Full Text Available Illusory contours are specific class of visual stimuli that represent stimuli configurations perceived as integral irrespective of the fact that they are given in fragmented uncompleted wholes. Due to their specific features, illusory contours gained much attention in last decade representing prototype of stimuli used in investigations focused on binding problem. On the other side, investigations of illusory contours are related to problem of the level of their visual processing. Neurophysiologic studies show that processing of illusory contours proceed relatively early, on the V2 level, on the other hand most of experimental studies claim that illusory contours are perceived with engagement of visual attention, binding their elements to whole percept. This research is focused on two experiments in which visual search of illusory contours are based on shape and orientation. The main experimental procedure evolved the task proposed by Bravo and Nakayama where instead of detection, subjects were performing identification of one among two possible targets. In the first experiment subjects detected the presence of illusory square or illusory triangle, while in the second experiment subject were detecting two different orientations of illusory triangle. The results are interpreted in terms of visual search and feature integration theory. Beside the type of visual search task, search type proved to be dependent of specific features of illusory shapes which further complicate theoretical interpretation of the level of their perception.

  7. Visual cortex activity predicts subjective experience after reading books with colored letters

    NARCIS (Netherlands)

    Colizoli, O.; Murre, J.M.J.; Scholte, H.S.; van Es, D.M.; Knapen, T.; Rouw, R.

    2016-01-01

    One of the most astonishing properties of synesthesia is that the evoked concurrent experiences are perceptual. Is it possible to acquire similar effects after learning cross-modal associations that resemble synesthetic mappings? In this study, we examine whether brain activation in early visual

  8. Visual Bias Predicts Gait Adaptability in Novel Sensory Discordant Conditions

    Science.gov (United States)

    Brady, Rachel A.; Batson, Crystal D.; Peters, Brian T.; Mulavara, Ajitkumar P.; Bloomberg, Jacob J.

    2010-01-01

    We designed a gait training study that presented combinations of visual flow and support-surface manipulations to investigate the response of healthy adults to novel discordant sensorimotor conditions. We aimed to determine whether a relationship existed between subjects visual dependence and their postural stability and cognitive performance in a new discordant environment presented at the conclusion of training (Transfer Test). Our training system comprised a treadmill placed on a motion base facing a virtual visual scene that provided a variety of sensory challenges. Ten healthy adults completed 3 training sessions during which they walked on a treadmill at 1.1 m/s while receiving discordant support-surface and visual manipulations. At the first visit, in an analysis of normalized torso translation measured in a scene-movement-only condition, 3 of 10 subjects were classified as visually dependent. During the Transfer Test, all participants received a 2-minute novel exposure. In a combined measure of stride frequency and reaction time, the non-visually dependent subjects showed improved adaptation on the Transfer Test compared to their visually dependent counterparts. This finding suggests that individual differences in the ability to adapt to new sensorimotor conditions may be explained by individuals innate sensory biases. An accurate preflight assessment of crewmembers biases for visual dependence could be used to predict their propensities to adapt to novel sensory conditions. It may also facilitate the development of customized training regimens that could expedite adaptation to alternate gravitational environments.

  9. Getting more from visual working memory: Retro-cues enhance retrieval and protect from visual interference.

    Science.gov (United States)

    Souza, Alessandra S; Rerko, Laura; Oberauer, Klaus

    2016-06-01

    Visual working memory (VWM) has a limited capacity. This limitation can be mitigated by the use of focused attention: if attention is drawn to the relevant working memory content before test, performance improves (the so-called retro-cue benefit). This study tests 2 explanations of the retro-cue benefit: (a) Focused attention protects memory representations from interference by visual input at test, and (b) focusing attention enhances retrieval. Across 6 experiments using color recognition and color reproduction tasks, we varied the amount of color interference at test, and the delay between a retrieval cue (i.e., the retro-cue) and the memory test. Retro-cue benefits were larger when the memory test introduced interfering visual stimuli, showing that the retro-cue effect is in part because of protection from visual interference. However, when visual interference was held constant, retro-cue benefits were still obtained whenever the retro-cue enabled retrieval of an object from VWM but delayed response selection. Our results show that accessible information in VWM might be lost in the processes of testing memory because of visual interference and incomplete retrieval. This is not an inevitable state of affairs, though: Focused attention can be used to get the most out of VWM. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  10. Influence of visual angle on pattern reversal visual evoked potentials

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    Ruchi Kothari

    2014-01-01

    Full Text Available Purpose: The aim of this study was to find whether the visual evoked potential (VEP latencies and amplitude are altered with different visual angles in healthy adult volunteers or not and to determine the visual angle which is the optimum and most appropriate among a wide range of check sizes for the reliable interpretation of pattern reversal VEPs (PRVEPs. Materials and Methods: The present study was conducted on 40 healthy volunteers. The subjects were divided into two groups. One group consisted of 20 individuals (nine males and 11 females in the age range of 25-57 years and they were exposed to checks subtending a visual angle of 90, 120, and 180 minutes of arc. Another group comprised of 20 individuals (10 males and 10 females in the age range of 36-60 years and they were subjected to checks subtending a visual angle of 15, 30, and 120 minutes of arc. The stimulus configuration comprised of the transient pattern reversal method in which a black and white checker board is generated (full field on a VEP Monitor by an Evoked Potential Recorder (RMS EMG. EPMARK II. The statistical analysis was done by One Way Analysis of Variance (ANOVA using EPI INFO 6. Results: In Group I, the maximum (max. P100 latency of 98.8 ± 4.7 and the max. P100 amplitude of 10.05 ± 3.1 μV was obtained with checks of 90 minutes. In Group II, the max. P100 latency of 105.19 ± 4.75 msec as well as the max. P100 amplitude of 8.23 ± 3.30 μV was obtained with 15 minutes. The min. P100 latency in both the groups was obtained with checks of 120 minutes while the min. P100 amplitude was obtained with 180 minutes. A statistically significant difference was derived between means of P100 latency for 15 and 30 minutes with reference to its value for 120 minutes and between the mean value of P100 amplitude for 120 minutes and that of 90 and 180 minutes. Conclusion: Altering the size of stimulus (visual angle has an effect on the PRVEP parameters. Our study found that the 120

  11. Facilitating Access to Emotions: Neural Signature of EMDR Stimulation

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    Herkt, Deborah; Tumani, Visal; Grön, Georg; Kammer, Thomas; Hofmann, Arne; Abler, Birgit

    2014-01-01

    Background Eye Movement Desensitisation and Reprocessing (EMDR) is a method in psychotherapy effective in treating symptoms of posttraumatic stress disorder. The client attends to alternating bilateral visual, auditory or sensory stimulation while confronted with emotionally disturbing material. It is thought that the bilateral stimulation as a specific element of EMDR facilitates accessing and processing of negative material while presumably creating new associative links. We hypothesized that the putatively facilitated access should be reflected in increased activation of the amygdala upon bilateral EMDR stimulation even in healthy subjects. Methods We investigated 22 healthy female university students (mean 23.5 years) with fMRI. Subjects were scanned while confronted with blocks of disgusting and neutral picture stimuli. One third of the blocks was presented without any additional stimulation, one third with bilateral simultaneous auditory stimulation, and one third with bilateral alternating auditory stimulation as used in EMDR. Results Contrasting disgusting vs. neutral picture stimuli confirmed the expected robust effect of amygdala activation for all auditory stimulation conditions. The interaction analysis with the type of auditory stimulation revealed a specific increase in activation of the right amygdala for the bilateral alternating auditory stimulation. Activation of the left dorsolateral prefrontal cortex showed the opposite effect with decreased activation. Conclusions We demonstrate first time evidence for a putative neurobiological basis of the bilateral alternating stimulation as used in the EMDR method. The increase in limbic processing along with decreased frontal activation is in line with theoretical models of how bilateral alternating stimulation could help with therapeutic reintegration of information, and present findings may pave the way for future research on EMDR in the context of posttraumatic stress disorder. PMID:25165974

  12. Do Visually Impaired People Develop Superior Smell Ability?

    Science.gov (United States)

    Majchrzak, Dorota; Eberhard, Julia; Kalaus, Barbara; Wagner, Karl-Heinz

    2017-10-01

    It is well known that visually impaired people perform better in orientation by sound than sighted individuals, but it is not clear whether this enhanced awareness also extends to other senses. Therefore, the aim of this study was to observe whether visually impaired subjects develop superior abilities in olfactory perception to compensate for their lack of vision. We investigated the odor perception of visually impaired individuals aged 7 to 89 ( n = 99; 52 women, 47 men) and compared them with subjects of a control group aged 8 to 82 years ( n = 100; 45 women, 55 men) without any visual impairment. The participants were evaluated by Sniffin' Sticks odor identification and discrimination test. Identification ability was assessed for 16 common odors presented in felt-tip pens. In the odor discrimination task, subjects had to determine which of three pens in 16 triplets had a different odor. The median number of correctly identified odorant pens in both groups was the same, 13 of the offered 16. In the discrimination test, there was also no significant difference observed. Gender did not influence results. Age-related changes were observed in both groups with olfactory perception decreasing after the age of 51. We could not confirm that visually impaired people were better in smell identification and discrimination ability than sighted individuals.

  13. Visual cues and listening effort: individual variability.

    Science.gov (United States)

    Picou, Erin M; Ricketts, Todd A; Hornsby, Benjamin W Y

    2011-10-01

    To investigate the effect of visual cues on listening effort as well as whether predictive variables such as working memory capacity (WMC) and lipreading ability affect the magnitude of listening effort. Twenty participants with normal hearing were tested using a paired-associates recall task in 2 conditions (quiet and noise) and 2 presentation modalities (audio only [AO] and auditory-visual [AV]). Signal-to-noise ratios were adjusted to provide matched speech recognition across audio-only and AV noise conditions. Also measured were subjective perceptions of listening effort and 2 predictive variables: (a) lipreading ability and (b) WMC. Objective and subjective results indicated that listening effort increased in the presence of noise, but on average the addition of visual cues did not significantly affect the magnitude of listening effort. Although there was substantial individual variability, on average participants who were better lipreaders or had larger WMCs demonstrated reduced listening effort in noise in AV conditions. Overall, the results support the hypothesis that integrating auditory and visual cues requires cognitive resources in some participants. The data indicate that low lipreading ability or low WMC is associated with relatively effortful integration of auditory and visual information in noise.

  14. Verbal overshadowing of visual memories: some things are better left unsaid.

    Science.gov (United States)

    Schooler, J W; Engstler-Schooler, T Y

    1990-01-01

    It is widely believed that verbal processing generally improves memory performance. However, in a series of six experiments, verbalizing the appearance of previously seen visual stimuli impaired subsequent recognition performance. In Experiment 1, subjects viewed a videotape including a salient individual. Later, some subjects described the individual's face. Subjects who verbalized the face performed less well on a subsequent recognition test than control subjects who did not engage in memory verbalization. The results of Experiment 2 replicated those of Experiment 1 and further clarified the effect of memory verbalization by demonstrating that visualization does not impair face recognition. In Experiments 3 and 4 we explored the hypothesis that memory verbalization impairs memory for stimuli that are difficult to put into words. In Experiment 3 memory impairment followed the verbalization of a different visual stimulus: color. In Experiment 4 marginal memory improvement followed the verbalization of a verbal stimulus: a brief spoken statement. In Experiments 5 and 6 the source of verbally induced memory impairment was explored. The results of Experiment 5 suggested that the impairment does not reflect a temporary verbal set, but rather indicates relatively long-lasting memory interference. Finally, Experiment 6 demonstrated that limiting subjects' time to make recognition decisions alleviates the impairment, suggesting that memory verbalization overshadows but does not eradicate the original visual memory. This collection of results is consistent with a recording interference hypothesis: verbalizing a visual memory may produce a verbally biased memory representation that can interfere with the application of the original visual memory.

  15. Specvis: Free and open-source software for visual field examination.

    Science.gov (United States)

    Dzwiniel, Piotr; Gola, Mateusz; Wójcik-Gryciuk, Anna; Waleszczyk, Wioletta J

    2017-01-01

    Visual field impairment affects more than 100 million people globally. However, due to the lack of the access to appropriate ophthalmic healthcare in undeveloped regions as a result of associated costs and expertise this number may be an underestimate. Improved access to affordable diagnostic software designed for visual field examination could slow the progression of diseases, such as glaucoma, allowing for early diagnosis and intervention. We have developed Specvis, a free and open-source application written in Java programming language that can run on any personal computer to meet this requirement (http://www.specvis.pl/). Specvis was tested on glaucomatous, retinitis pigmentosa and stroke patients and the results were compared to results using the Medmont M700 Automated Static Perimeter. The application was also tested for inter-test intrapersonal variability. The results from both validation studies indicated low inter-test intrapersonal variability, and suitable reliability for a fast and simple assessment of visual field impairment. Specvis easily identifies visual field areas of zero sensitivity and allows for evaluation of its levels throughout the visual field. Thus, Specvis is a new, reliable application that can be successfully used for visual field examination and can fill the gap between confrontation and perimetry tests. The main advantages of Specvis over existing methods are its availability (free), affordability (runs on any personal computer), and reliability (comparable to high-cost solutions).

  16. Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory.

    Science.gov (United States)

    Kawasaki, Masahiro; Kitajo, Keiichi; Yamaguchi, Yoko

    2014-01-01

    In humans, theta phase (4-8 Hz) synchronization observed on electroencephalography (EEG) plays an important role in the manipulation of mental representations during working memory (WM) tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

  17. Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory

    Directory of Open Access Journals (Sweden)

    Masahiro eKawasaki

    2014-03-01

    Full Text Available In humans, theta phase (4–8 Hz synchronization observed on electroencephalography (EEG plays an important role in the manipulation of mental representations during working memory (WM tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

  18. Auditory and visual spatial impression: Recent studies of three auditoria

    Science.gov (United States)

    Nguyen, Andy; Cabrera, Densil

    2004-10-01

    Auditory spatial impression is widely studied for its contribution to auditorium acoustical quality. By contrast, visual spatial impression in auditoria has received relatively little attention in formal studies. This paper reports results from a series of experiments investigating the auditory and visual spatial impression of concert auditoria. For auditory stimuli, a fragment of an anechoic recording of orchestral music was convolved with calibrated binaural impulse responses, which had been made with the dummy head microphone at a wide range of positions in three auditoria and the sound source on the stage. For visual stimuli, greyscale photographs were used, taken at the same positions in the three auditoria, with a visual target on the stage. Subjective experiments were conducted with auditory stimuli alone, visual stimuli alone, and visual and auditory stimuli combined. In these experiments, subjects rated apparent source width, listener envelopment, intimacy and source distance (auditory stimuli), and spaciousness, envelopment, stage dominance, intimacy and target distance (visual stimuli). Results show target distance to be of primary importance in auditory and visual spatial impression-thereby providing a basis for covariance between some attributes of auditory and visual spatial impression. Nevertheless, some attributes of spatial impression diverge between the senses.

  19. Objective Evaluation of Visual Fatigue Using Binocular Fusion Maintenance.

    Science.gov (United States)

    Hirota, Masakazu; Morimoto, Takeshi; Kanda, Hiroyuki; Endo, Takao; Miyoshi, Tomomitsu; Miyagawa, Suguru; Hirohara, Yoko; Yamaguchi, Tatsuo; Saika, Makoto; Fujikado, Takashi

    2018-03-01

    In this study, we investigated whether an individual's visual fatigue can be evaluated objectively and quantitatively from their ability to maintain binocular fusion. Binocular fusion maintenance (BFM) was measured using a custom-made binocular open-view Shack-Hartmann wavefront aberrometer equipped with liquid crystal shutters, wherein eye movements and wavefront aberrations were measured simultaneously. Transmittance in the liquid crystal shutter in front of the subject's nondominant eye was reduced linearly, and BFM was determined from the transmittance at the point when binocular fusion was broken and vergence eye movement was induced. In total, 40 healthy subjects underwent the BFM test and completed a questionnaire regarding subjective symptoms before and after a visual task lasting 30 minutes. BFM was significantly reduced after the visual task ( P eye symptom score (adjusted R 2 = 0.752, P devices, such as head-mount display, objectively.

  20. Bridging the Divide: Literature, Dao and the Case for Subjective Access in the Thought of Su Shi

    Directory of Open Access Journals (Sweden)

    Curie Virág

    2014-10-01

    Full Text Available In the 11th century in China, there was an unusual moment in which a number of philosophers, later associated with the Daoxue—or Neo-Confucian—school, confronted what they perceived as a long-standing sense of disjunction between inner, subjective reality and the structured patterns of the cosmos. One way they sought to overcome this disjunction was by positing new theories of the cosmos that focused on the underlying, shared reality behind the myriad differentiations of phenomena. A potential tension was born that affected how thinkers understood the relationship between wen 文 (writing, literature, culture and Dao 道 (the cosmic process, the ultimate reality, the normative path. Some thinkers, like Zhou Dunyi 周敦頤 (1017–1073, believed that wen was simply a vehicle for carrying the Dao, and was thus, implicitly, dispensable. This idea was met with resistance from one of the leading intellectual figures of the time—the philosopher, poet and statesman Su Shi 蘇軾 (1037–1101. While some of Su’s contemporaries, in their attempts to demonstrate that the world was real, and that truth was knowable, downplayed the role of individual experience and perception, Su stressed the necessity of subjective, individual experience as giving access, and concrete expression, to Dao. Su’s philosophical project came in the form of defending the enterprise of wen—writing as a creative, individual endeavor—and asserting that the quest for unity with the Dao could only be realized through direct, personal engagement in wen and other forms of meaningful practice. Through his philosophy of wen, Su sought to show that the search for truth, meaning and order did not—and could not—be achieved by transcending subjective experience. Instead, it had to be carried out at the point of encounter between self and the world, in the realm of practice.

  1. Recruitment of occipital cortex during sensory substitution training linked to subjective experience of seeing in people with blindness.

    Directory of Open Access Journals (Sweden)

    Tomás Ortiz

    Full Text Available Over three months of intensive training with a tactile stimulation device, 18 blind and 10 blindfolded seeing subjects improved in their ability to identify geometric figures by touch. Seven blind subjects spontaneously reported 'visual qualia', the subjective sensation of seeing flashes of light congruent with tactile stimuli. In the latter subjects tactile stimulation evoked activation of occipital cortex on electroencephalography (EEG. None of the blind subjects who failed to experience visual qualia, despite identical tactile stimulation training, showed EEG recruitment of occipital cortex. None of the blindfolded seeing humans reported visual-like sensations during tactile stimulation. These findings support the notion that the conscious experience of seeing is linked to the activation of occipital brain regions in people with blindness. Moreover, the findings indicate that provision of visual information can be achieved through non-visual sensory modalities which may help to minimize the disability of blind individuals, affording them some degree of object recognition and navigation aid.

  2. Recruitment of occipital cortex during sensory substitution training linked to subjective experience of seeing in people with blindness.

    Science.gov (United States)

    Ortiz, Tomás; Poch, Joaquín; Santos, Juan M; Requena, Carmen; Martínez, Ana M; Ortiz-Terán, Laura; Turrero, Agustín; Barcia, Juan; Nogales, Ramón; Calvo, Agustín; Martínez, José M; Córdoba, José L; Pascual-Leone, Alvaro

    2011-01-01

    Over three months of intensive training with a tactile stimulation device, 18 blind and 10 blindfolded seeing subjects improved in their ability to identify geometric figures by touch. Seven blind subjects spontaneously reported 'visual qualia', the subjective sensation of seeing flashes of light congruent with tactile stimuli. In the latter subjects tactile stimulation evoked activation of occipital cortex on electroencephalography (EEG). None of the blind subjects who failed to experience visual qualia, despite identical tactile stimulation training, showed EEG recruitment of occipital cortex. None of the blindfolded seeing humans reported visual-like sensations during tactile stimulation. These findings support the notion that the conscious experience of seeing is linked to the activation of occipital brain regions in people with blindness. Moreover, the findings indicate that provision of visual information can be achieved through non-visual sensory modalities which may help to minimize the disability of blind individuals, affording them some degree of object recognition and navigation aid.

  3. A novel apparatus for testing binocular function using the 'CyberDome' three-dimensional hemispherical visual display system.

    Science.gov (United States)

    Handa, T; Ishikawa, H; Shimizu, K; Kawamura, R; Nakayama, H; Sawada, K

    2009-11-01

    Virtual reality has recently been highlighted as a promising medium for visual presentation and entertainment. A novel apparatus for testing binocular visual function using a hemispherical visual display system, 'CyberDome', has been developed and tested. Subjects comprised 40 volunteers (mean age, 21.63 years) with corrected visual acuity of -0.08 (LogMAR) or better, and stereoacuity better than 100 s of arc on the Titmus stereo test. Subjects were able to experience visual perception like being surrounded by visual images, a feature of the 'CyberDome' hemispherical visual display system. Visual images to the right and left eyes were projected and superimposed on the dome screen, allowing test images to be seen independently by each eye using polarizing glasses. The hemispherical visual display was 1.4 m in diameter. Three test parameters were evaluated: simultaneous perception (subjective angle of strabismus), motor fusion amplitude (convergence and divergence), and stereopsis (binocular disparity at 1260, 840, and 420 s of arc). Testing was performed in volunteer subjects with normal binocular vision, and results were compared with those using a major amblyoscope. Subjective angle of strabismus and motor fusion amplitude showed a significant correlation between our test and the major amblyoscope. All subjects could perceive the stereoscopic target with a binocular disparity of 480 s of arc. Our novel apparatus using the CyberDome, a hemispherical visual display system, was able to quantitatively evaluate binocular function. This apparatus offers clinical promise in the evaluation of binocular function.

  4. Visual discomfort in stereoscopic displays : a review

    NARCIS (Netherlands)

    Lambooij, M.T.M.; IJsselsteijn, W.A.; Heynderickx, I.E.J.; Woods, A.J.; Merritt, J.O.; Bolas, M.T.; McDowall, I.E.

    2007-01-01

    Visual discomfort has been the subject of considerable research in relation to stereoscopic and autostereoscopic displays, but remains an ambiguous concept used to denote a variety of subjective symptoms potentially related to different underlying processes. In this paper we clarify the importance

  5. Visual discomfort in stereoscopic dsplays : A review

    NARCIS (Netherlands)

    Lambooij, M.T.M.; IJsselsteijn, W.; Heynderickx, I.

    2007-01-01

    Visual discomfort has been the subject of considerable research in relation to stereoscopic and autostereoscopic displays, but remains an ambiguous concept used to denote a variety of subjective symptoms potentially related to different underlying processes. In this paper we clarify the importance

  6. On the interplay between working memory consolidation and attentional selection in controlling conscious access : Parallel processing at a cost-a comment on 'The interplay of attention and consciousness in visual search, attentional blink and working memory consolidation'

    NARCIS (Netherlands)

    Wyble, Brad; Bowman, Howard; Nieuwenstein, Mark

    On the interplay between working memory consolidation and attentional selection in controlling conscious access: parallel processing at a cost-a comment on 'The interplay of attention and consciousness in visual search, attentional blink and working memory consolidation'

  7. Visual dependence and spatial orientation in benign paroxysmal positional vertigo.

    Science.gov (United States)

    Nair, Maitreyi A; Mulavara, Ajitkumar P; Bloomberg, Jacob J; Sangi-Haghpeykar, Haleh; Cohen, Helen S

    2018-01-01

    People with benign paroxysmal positional vertigo (BPPV) probably have otoconial particles displaced from the utricle into the posterior semicircular canal. This unilateral change in the inertial load distributions of the labyrinth may result in visual dependence and may affect balance control. The goal of this study was to explore the interaction between visual dependence and balance control. We compared 23 healthy controls to 17 people with unilateral BPPV on the Clinical Test of Sensory Interaction and Balance on compliant foam with feet together, the Rod-and-Frame Test and a Mental Rotation Test. In controls, but not BPPV subjects, subjects with poor balance scores had significantly greater visual dependence, indicating that reliance on visual cues can affect balance control. BPPV and control subjects did not differ on the mental rotation task overall but BPPV reaction time was greater at greater orietantions, suggesting that this cognitive function was affected by BPPV. The side of impairment was strongly related to the side of perceived bias in the Earth vertical determined by BPPV subjects, indicating the relationship between the effect of asymmetric otolith unloading with simultaneous canal loading on spatial orientation perception.

  8. Visual comfort evaluated by opponent colors

    Science.gov (United States)

    Sagawa, Ken

    2002-06-01

    This study aimed to evaluate psychological impression of visual comfort when we see an image of ordinary colored scene presented in a color display. Effects of opponent colors, i.e. red, green, yellow and blue component, on the subjective judgement on visual comfort to the image were investigated. Three kinds of psychological experiment were designed to see the effects and the results indicated that the red/green opponent color component was more affecting than the yellow-blue one, and red color in particular was the most affecting factor on visual comfort.

  9. Visually observing comets

    CERN Document Server

    Seargent, David A J

    2017-01-01

    In these days of computers and CCD cameras, visual comet observers can still contribute scientifically useful data with the help of this handy reference for use in the field. Comets are one of the principal areas for productive pro-amateur collaboration in astronomy, but finding comets requires a different approach than the observing of more predictable targets. Principally directed toward amateur astronomers who prefer visual observing or who are interested in discovering a new comet or visually monitoring the behavior of known comets, it includes all the advice needed to thrive as a comet observer. After presenting a brief overview of the nature of comets and how we came to the modern understanding of comets, this book details the various types of observations that can usefully be carried out at the eyepiece of a telescope. Subjects range from how to search for new comets to visually estimating the brightness of comets and the length and orientation of tails, in addition to what to look for in comet heads a...

  10. Activation of Visuomotor Systems during Visually Guided Movements: A Functional MRI Study

    Science.gov (United States)

    Ellermann, Jutta M.; Siegal, Joel D.; Strupp, John P.; Ebner, Timothy J.; Ugurbil, Kâmil

    1998-04-01

    The dorsal stream is a dominant visuomotor pathway that connects the striate and extrastriate cortices to posterior parietal areas. In turn, the posterior parietal areas send projections to the frontal primary motor and premotor areas. This cortical pathway is hypothesized to be involved in the transformation of a visual input into the appropriate motor output. In this study we used functional magnetic resonance imaging (fMRI) of the entire brain to determine the patterns of activation that occurred while subjects performed a visually guided motor task. In nine human subjects, fMRI data were acquired on a 4-T whole-body MR system equipped with a head gradient coil and a birdcage RF coil using aT*2-weighted EPI sequence. Functional activation was determined for three different tasks: (1) a visuomotor task consisting of moving a cursor on a screen with a joystick in relation to various targets, (2) a hand movement task consisting of moving the joystick without visual input, and (3) a eye movement task consisting of moving the eyes alone without visual input. Blood oxygenation level-dependent (BOLD) contrast-based activation maps of each subject were generated using period cross-correlation statistics. Subsequently, each subject's brain was normalized to Talairach coordinates, and the individual maps were compared on a pixel by pixel basis. Significantly activated pixels common to at least four out of six subjects were retained to construct the final functional image. The pattern of activation during visually guided movements was consistent with the flow of information from striate and extrastriate visual areas, to the posterior parietal complex, and then to frontal motor areas. The extensive activation of this network and the reproducibility among subjects is consistent with a role for the dorsal stream in transforming visual information into motor behavior. Also extensively activated were the medial and lateral cerebellar structures, implicating the cortico

  11. A comparison of visual and kinesthetic-tactual displays for compensatory tracking

    Science.gov (United States)

    Jagacinski, R. J.; Flach, J. M.; Gilson, R. D.

    1983-01-01

    Recent research on manual tracking with a kinesthetic-tactual (KT) display suggests that under certain conditions it can be an effective alternative or supplement to visual displays. In order to understand better how KT tracking compares with visual tracking, both a critical tracking and stationary single-axis tracking tasks were conducted with and without velocity quickening. In the critical tracking task, the visual displays were superior, however, the quickened KT display was approximately equal to the unquickened visual display. In stationary tracking tasks, subjects adopted lag equalization with the quickened KT and visual displays, and mean-squared error scores were approximately equal. With the unquickened displays, subjects adopted lag-lead equalization, and the visual displays were superior. This superiority was partly due to the servomotor lag in the implementation of the KT display and partly due to modality differences.

  12. PathwayAccess: CellDesigner plugins for pathway databases.

    Science.gov (United States)

    Van Hemert, John L; Dickerson, Julie A

    2010-09-15

    CellDesigner provides a user-friendly interface for graphical biochemical pathway description. Many pathway databases are not directly exportable to CellDesigner models. PathwayAccess is an extensible suite of CellDesigner plugins, which connect CellDesigner directly to pathway databases using respective Java application programming interfaces. The process is streamlined for creating new PathwayAccess plugins for specific pathway databases. Three PathwayAccess plugins, MetNetAccess, BioCycAccess and ReactomeAccess, directly connect CellDesigner to the pathway databases MetNetDB, BioCyc and Reactome. PathwayAccess plugins enable CellDesigner users to expose pathway data to analytical CellDesigner functions, curate their pathway databases and visually integrate pathway data from different databases using standard Systems Biology Markup Language and Systems Biology Graphical Notation. Implemented in Java, PathwayAccess plugins run with CellDesigner version 4.0.1 and were tested on Ubuntu Linux, Windows XP and 7, and MacOSX. Source code, binaries, documentation and video walkthroughs are freely available at http://vrac.iastate.edu/~jlv.

  13. Defining the Limits of Endoscopic Access to Internal Auditory Canal.

    Science.gov (United States)

    Master, Adam; Hamiter, Mickie; Cosetti, Maura

    2016-12-01

    To quantify surgical access to the internal auditory canal (IAC) using an exclusively endoscopic transcanal approach (EETA) and investigate surgically relevant relationships with neurovascular and osseous landmarks of the temporal bone. Anatomical dissection of two paired temporal bones and 15 unpaired temporal bones was performed using an exclusively endoscopic approach to IAC. The dissection proceeded until the cerebellopontine angle (CPA) could be accessed. Following dissection, all the specimens were subjected to computed tomography (CT) imaging. Anatomage InVivo5 software was used to analyze the CT scans and record measurements. CPA access and visualization of the labyrinthine segment of the facial nerve were achieved in all specimens. The mean distances from the carotid artery, jugular bulb, and middle fossa to the surgical opening (or fundostomy) of IAC were 4.1±1.5, 6.4±2.5, and 5.5±1.9 mm, respectively. The mean cross-sectional areas of the fundostomy and tympanic ring were 30.8±10.4 and 67.7±11.3 mm2. The mean distances from the osteo-cartilaginous junction and tympanic ring to the porus acusticus were 29±2.6 and 21±2.3 mm, respectively. Transcanal access to the entire IAC can be safely achieved using an exclusively endoscopic approach. Generous removal of the cochlear promontory can be accomplished while a safe distance is maintained from key neurovascular structures. EETA to IAC offers a minimally invasive alternative to patients without serviceable hearing for intrameatal and medial IAC tumors. Increased knowledge of crucial anatomical relationships involved in this approach will facilitate acceptance and utilization.

  14. Cerebral Asymmetry of fMRI-BOLD Responses to Visual Stimulation

    DEFF Research Database (Denmark)

    Hougaard, Anders; Jensen, Bettina Hagström; Amin, Faisal Mohammad

    2015-01-01

    Hemispheric asymmetry of a wide range of functions is a hallmark of the human brain. The visual system has traditionally been thought of as symmetrically distributed in the brain, but a growing body of evidence has challenged this view. Some highly specific visual tasks have been shown to depend......MRI) in 54 healthy subjects during stimulation with a black and white checkerboard visual stimulus. While carefully excluding possible non-physiological causes of left-to-right bias, we compared the activation of the left and the right cerebral hemispheres and related this to grey matter volume, handedness...... was correlated with subject age, suggesting a shift towards the left hemisphere with increasing age. Our findings suggest a right-hemispheric dominance of these areas, which could lend support to the generally observed leftward visual attentional bias and to the left hemifield advantage for some visual...

  15. Normative perceptual estimates for 91 healthy subjects age 60-75

    DEFF Research Database (Denmark)

    Wilms, Inge Linda; Nielsen, Simon

    2014-01-01

    Visual perception serves as the basis for much of the higher level cognitive processing as well as human activity in general. Here we present normative estimates for the following components of visual perception: the visual perceptual threshold, the visual short-term memory capacity and the visual...... perceptual encoding/decoding speed (processing speed) of visual short-term memory based on an assessment of 91 healthy subjects aged 60-75. The estimates are presented at total sample level as well as at gender level. The estimates were modelled from input from a whole-report assessment based on A Theory...... speed of Visual Short-term Memory (VTSM) but not the capacity of VSTM nor the visual threshold. The estimates will be useful for future studies into the effects of various types of intervention and training on cognition in general and visual attention in particular....

  16. Can Dynamic Visualizations Improve Middle School Students' Understanding of Energy in Photosynthesis?

    Science.gov (United States)

    Ryoo, Kihyun; Linn, Marcia C.

    2012-01-01

    Dynamic visualizations have the potential to make abstract scientific phenomena more accessible and visible to students, but they can also be confusing and difficult to comprehend. This research investigates how dynamic visualizations, compared to static illustrations, can support middle school students in developing an integrated understanding of…

  17. A Network and Visual Quality Aware N-Screen Content Recommender System Using Joint Matrix Factorization

    Directory of Open Access Journals (Sweden)

    Farman Ullah

    2014-01-01

    Full Text Available We propose a network and visual quality aware N-Screen content recommender system. N-Screen provides more ways than ever before to access multimedia content through multiple devices and heterogeneous access networks. The heterogeneity of devices and access networks present new questions of QoS (quality of service in the realm of user experience with content. We propose, a recommender system that ensures a better visual quality on user’s N-screen devices and the efficient utilization of available access network bandwidth with user preferences. The proposed system estimates the available bandwidth and visual quality on users N-Screen devices and integrates it with users preferences and contents genre information to personalize his N-Screen content. The objective is to recommend content that the user’s N-Screen device and access network are capable of displaying and streaming with the user preferences that have not been supported in existing systems. Furthermore, we suggest a joint matrix factorization approach to jointly factorize the users rating matrix with the users N-Screen device similarity and program genres similarity. Finally, the experimental results show that we also enhance the prediction and recommendation accuracy, sparsity, and cold start issues.

  18. A network and visual quality aware N-screen content recommender system using joint matrix factorization.

    Science.gov (United States)

    Ullah, Farman; Sarwar, Ghulam; Lee, Sungchang

    2014-01-01

    We propose a network and visual quality aware N-Screen content recommender system. N-Screen provides more ways than ever before to access multimedia content through multiple devices and heterogeneous access networks. The heterogeneity of devices and access networks present new questions of QoS (quality of service) in the realm of user experience with content. We propose, a recommender system that ensures a better visual quality on user's N-screen devices and the efficient utilization of available access network bandwidth with user preferences. The proposed system estimates the available bandwidth and visual quality on users N-Screen devices and integrates it with users preferences and contents genre information to personalize his N-Screen content. The objective is to recommend content that the user's N-Screen device and access network are capable of displaying and streaming with the user preferences that have not been supported in existing systems. Furthermore, we suggest a joint matrix factorization approach to jointly factorize the users rating matrix with the users N-Screen device similarity and program genres similarity. Finally, the experimental results show that we also enhance the prediction and recommendation accuracy, sparsity, and cold start issues.

  19. Foundation for a Time Interval Access Control Model

    National Research Council Canada - National Science Library

    Afinidad, Francis B; Levin, Timothy E; Irvine, Cynthia E; Nguyen, Thuy D

    2005-01-01

    A new model for representing temporal access control policies is introduced. In this model, temporal authorizations are represented by time attributes associated with both subjects and objects, and a time interval access graph...

  20. Are there multiple visual short-term memory stores?

    Science.gov (United States)

    Sligte, Ilja G; Scholte, H Steven; Lamme, Victor A F

    2008-02-27

    Classic work on visual short-term memory (VSTM) suggests that people store a limited amount of items for subsequent report. However, when human observers are cued to shift attention to one item in VSTM during retention, it seems as if there is a much larger representation, which keeps additional items in a more fragile VSTM store. Thus far, it is not clear whether the capacity of this fragile VSTM store indeed exceeds the traditional capacity limits of VSTM. The current experiments address this issue and explore the capacity, stability, and duration of fragile VSTM representations. We presented cues in a change-detection task either just after off-set of the memory array (iconic-cue), 1,000 ms after off-set of the memory array (retro-cue) or after on-set of the probe array (post-cue). We observed three stages in visual information processing 1) iconic memory with unlimited capacity, 2) a four seconds lasting fragile VSTM store with a capacity that is at least a factor of two higher than 3) the robust and capacity-limited form of VSTM. Iconic memory seemed to depend on the strength of the positive after-image resulting from the memory display and was virtually absent under conditions of isoluminance or when intervening light masks were presented. This suggests that iconic memory is driven by prolonged retinal activation beyond stimulus duration. Fragile VSTM representations were not affected by light masks, but were completely overwritten by irrelevant pattern masks that spatially overlapped the memory array. We find that immediately after a stimulus has disappeared from view, subjects can still access information from iconic memory because they can see an after-image of the display. After that period, human observers can still access a substantial, but somewhat more limited amount of information from a high-capacity, but fragile VSTM that is overwritten when new items are presented to the eyes. What is left after that is the traditional VSTM store, with a limit of

  1. Are there multiple visual short-term memory stores?

    Directory of Open Access Journals (Sweden)

    Ilja G Sligte

    Full Text Available BACKGROUND: Classic work on visual short-term memory (VSTM suggests that people store a limited amount of items for subsequent report. However, when human observers are cued to shift attention to one item in VSTM during retention, it seems as if there is a much larger representation, which keeps additional items in a more fragile VSTM store. Thus far, it is not clear whether the capacity of this fragile VSTM store indeed exceeds the traditional capacity limits of VSTM. The current experiments address this issue and explore the capacity, stability, and duration of fragile VSTM representations. METHODOLOGY/PRINCIPAL FINDINGS: We presented cues in a change-detection task either just after off-set of the memory array (iconic-cue, 1,000 ms after off-set of the memory array (retro-cue or after on-set of the probe array (post-cue. We observed three stages in visual information processing 1 iconic memory with unlimited capacity, 2 a four seconds lasting fragile VSTM store with a capacity that is at least a factor of two higher than 3 the robust and capacity-limited form of VSTM. Iconic memory seemed to depend on the strength of the positive after-image resulting from the memory display and was virtually absent under conditions of isoluminance or when intervening light masks were presented. This suggests that iconic memory is driven by prolonged retinal activation beyond stimulus duration. Fragile VSTM representations were not affected by light masks, but were completely overwritten by irrelevant pattern masks that spatially overlapped the memory array. CONCLUSIONS/SIGNIFICANCE: We find that immediately after a stimulus has disappeared from view, subjects can still access information from iconic memory because they can see an after-image of the display. After that period, human observers can still access a substantial, but somewhat more limited amount of information from a high-capacity, but fragile VSTM that is overwritten when new items are presented

  2. Subjective figures and texture perception.

    Science.gov (United States)

    Zucker, S W; Cavanagh, P

    1985-01-01

    A texture discrimination task using the Ehrenstein illusion demonstrates that subjective brightness effects can play an essential role in early vision. The subjectively bright regions of the Ehrenstein can be organized either as discs or as stripes, depending on orientation. The accuracy of discrimination between variants of the Ehrenstein and control patterns was a direct function of the presence of the illusory brightness stripes, being high when they were present and low otherwise. It is argued that neither receptive field structure nor spatial-frequency content can adequately account for these results. We suggest that the subjective brightness illusions, rather than being a high-level, cognitive aspect of vision, are in fact the result of an early visual process.

  3. Final Report. Institute for Ultralscale Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Kwan-Liu [Univ. of California, Davis, CA (United States); Galli, Giulia [Univ. of California, Davis, CA (United States); Gygi, Francois [Univ. of California, Davis, CA (United States); Max, Nelson [Univ. of California, Davis, CA (United States); Owens, John [Univ. of California, Davis, CA (United States); Pickett, Warren [Univ. of California, Davis, CA (United States); Huang, Jian [Univ. of Tennessee, Knoxville, TN (United States); Humphreys, Gregory [NVIDIA Corp., Santa Clara, CA (United States); Moreland, Kenneth [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ross, Rob [Argonne National Lab. (ANL), Argonne, IL (United States); Shen, Han-Wei [The Ohio State Univ., Columbus, OH (United States); Silver, Deborah [Rutgers Univ., New Brunswick, NJ (United States)

    2015-03-01

    The SciDAC Institute for Ultrascale Visualization brought together leading experts from visualization, high-performance computing, and science application areas to make advanced visualization solutions for SciDAC scientists and the broader community. Over the five-year project, the Institute introduced many new enabling visualization techniques, which have significantly enhanced scientists’ ability to validate their simulations, interpret their data, and communicate with others about their work and findings. This Institute project involved a large number of junior and student researchers, who received the opportunities to work on some of the most challenging science applications and gain access to the most powerful high-performance computing facilities in the world. They were readily trained and prepared for facing the greater challenges presented by extreme-scale computing. The Institute’s outreach efforts, through publications, workshops and tutorials, successfully disseminated the new knowledge and technologies to the SciDAC and the broader scientific communities. The scientific findings and experience of the Institute team helped plan the SciDAC3 program.

  4. Endogenously generated gamma-band oscillations in early visual cortex: A neurofeedback study.

    Science.gov (United States)

    Merkel, Nina; Wibral, Michael; Bland, Gareth; Singer, Wolf

    2018-04-26

    Human subjects were trained with neurofeedback (NFB) to enhance the power of narrow-band gamma oscillations in circumscribed regions of early visual cortex. To select the region and the oscillation frequency for NFB training, gamma oscillations were induced with locally presented drifting gratings. The source and frequency of these induced oscillations were determined using beamforming methods. During NFB training the power of narrow band gamma oscillations was continuously extracted from this source with online beamforming and converted into the pitch of a tone signal. We found that seven out of ten subjects were able to selectively increase the amplitude of gamma oscillations in the absence of visual stimulation. One subject however failed completely and two subjects succeeded to manipulate the feedback signal by contraction of muscles. In all subjects the attempts to enhance visual gamma oscillations were associated with an increase of beta oscillations over precentral/frontal regions. Only successful subjects exhibited an additional marked increase of theta oscillations over precentral/prefrontal and temporal regions whereas unsuccessful subjects showed an increase of alpha band oscillations over occipital regions. We argue that spatially confined networks in early visual cortex can be entrained to engage in narrow band gamma oscillations not only by visual stimuli but also by top down signals. We interpret the concomitant increase in beta oscillations as indication for an engagement of the fronto-parietal attention network and the increase of theta oscillations as a correlate of imagery. Our finding support the application of NFB in disease conditions associated with impaired gamma synchronization. © 2018 Wiley Periodicals, Inc.

  5. N1 enhancement in synesthesia during visual and audio-visual perception in semantic cross-modal conflict situations: an ERP study

    Directory of Open Access Journals (Sweden)

    Christopher eSinke

    2014-01-01

    Full Text Available Synesthesia entails a special kind of sensory perception, where stimulation in one sensory modality leads to an internally generated perceptual experience of another, not stimulated sensory modality. This phenomenon can be viewed as an abnormal multisensory integration process as here the synesthetic percept is aberrantly fused with the stimulated modality. Indeed, recent synesthesia research has focused on multimodal processing even outside of the specific synesthesia-inducing context and has revealed changed multimodal integration, thus suggesting perceptual alterations at a global level. Here, we focused on audio-visual processing in synesthesia using a semantic classification task in combination with visually or auditory-visually presented animated and inanimated objects in an audio-visual congruent and incongruent manner. Fourteen subjects with auditory-visual and/or grapheme-color synesthesia and 14 control subjects participated in the experiment. During presentation of the stimuli, event-related potentials were recorded from 32 electrodes. The analysis of reaction times and error rates revealed no group differences with best performance for audio-visually congruent stimulation indicating the well-known multimodal facilitation effect. We found an enhanced amplitude of the N1 component over occipital electrode sites for synesthetes compared to controls. The differences occurred irrespective of the experimental condition and therefore suggest a global influence on early sensory processing in synesthetes.

  6. Pattern visual evoked potentials in malingering.

    Science.gov (United States)

    Nakamura, A; Akio, T; Matsuda, E; Wakami, Y

    2001-03-01

    We previously developed a new method for estimating objective visual acuity by means of pattern visual evoked potentials (PVEP). In this study, this method was applied to the diagnosis of malingering. Six patients ranging in age from 40 to 54 years (mean 47 years) with suspected malingering were evaluated by means of the visual evoked potential test, optokinetic nystagmus (OKN) inhibition test, and the visual field test. In the PVEP study, the stimulus consisted of black and white checkerboards (39', 26', 15', and 9') with a visual angle of 8 degrees, contrast level of 15%, and a frequency of 0.7 Hz. One hundred PVEP responses were averaged per session. Routine ophthalmic examinations were normal in all patients. Five patients had a tubularly constricted visual field, and the remaining patient had a normal visual field. The objective visual acuities of the six patients estimated from PVEP were better than their subjective visual acuities estimated with Landolt rings. Among a variety of psychophysical and electrophysiologic ancillary tests, we consider our PVEP method a useful method for objectively determining visual acuity in a patient with signs of ocular malingering.

  7. Examining Practice in Secondary Visual Arts Education

    Science.gov (United States)

    Mitchell, Donna Mathewson

    2015-01-01

    Teaching in secondary visual arts classrooms is complex and challenging work. While it is implicated in much research, the complexity of the lived experience of secondary visual arts teaching has rarely been the subject of sustained and synthesized research. In this paper, the potential of practice as a concept to examine and represent secondary…

  8. 40 CFR 202.23 - Visual tire inspection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Visual tire inspection. 202.23 Section... Visual tire inspection. No motor carrier subject to these regulations shall at any time operate any motor vehicle of a type to which this regulation is applicable on a tire or tires having a tread pattern which...

  9. Optimizing visualization in enhanced depth imaging OCT in healthy subjects and patients with retinal pigment epithelial detachment

    Directory of Open Access Journals (Sweden)

    Kampik A

    2012-11-01

    Full Text Available Lukas Reznicek, Efstathios Vounotrypidis, Florian Seidensticker, Karsten Kortuem, Anselm Kampik, Aljoscha S Neubauer, Armin WolfDepartment of Ophthalmology, Ludwig Maximilians University Muenchen, Munich, GermanyBackground: This study’s objective was to optimize the visualization of three different spectral-domain optical coherence tomography (SD-OCT display modalities and evaluate enhanced depth imaging (EDI by comparing the maximum depth of assessment in conventional versus inverted cross-sectional OCT images in healthy subjects and in patients with retinal pigment epithelial detachment (PED.Methods: Cross-sectional SD-OCT conventional and inverted images were obtained with the HRA2 (Heidelberg Retina Angiograph II, Heidelberg Engineering, Heidelberg, Germany. Horizontal as well as vertical sections in three different display modes were blinded for evaluation by three independent, experienced graders for maximal imaging depth of the deep ocular fundus layers.Results: The mean imaging depth as measured from the inner segment/outer segment (IS/OS to the outer choroid of all 14 healthy subjects was 197 ± 44 µm vs 263 ± 56 µm for conventional vs EDI scans: in black/white mode, it was significantly lower (P < 0.001 than in white/black mode (249 ± 42 µm vs 337 ± 71 µm and color/heat mode (254 ± 48 µm vs 354 ± 73 µm. The mean imaging depth of all 14 study eyes with PED was 240 ± 78 µm vs 345 ± 100 µm for conventional vs EDI scans in black/white mode, and was significantly lower (P < 0.001 than in white/black mode (393 ± 104 µm vs 464 ± 126 µm and in color/heat mode (373 ± 106 µm vs 453 ± 114 µm. In each display modality of healthy subjects and of patients with PED, EDI scans showed a significantly higher imaging depth than the corresponding conventional scans.Conclusion: White/black and color/heat modes allow increased imaging depth, compared to black/white mode using both conventional or EDI OCT scans in healthy subjects or

  10. Application of digital tomosynthesis to radiographic diagnosis of the temporal bone. Studies on visualization in normal subjects

    International Nuclear Information System (INIS)

    Kawai, Takashi

    1995-01-01

    To examine the usefulness of digital tomosynthesis for conducting radiographic diagnosis of the temporal bone, visualization of various aural structures such as the semicircular canals, cochlea, vestibular apparatus, ossicles of the ear and facial nerve canal was examined in 18 volunteers. The visualization of temporal bone specimens by digital tomosynthesis and CT images (slice thickness: 1.5 mm) was compared. The results showed that this system (Digital Tomosynthesis) produced clear images of bony labyrinthine structures such as the semicircular canals, cochlea, and vestibular apparatus. Visualization of the ossicles was also clear, and their continuity could be comprehended better than on CT images. This system also provided good visualization of the labyrinthine and tympanic parts of the facial nerve canal, although CT images had greater sharpness. Visualization of the lower half of the mastoid part was poor with this system. (author)

  11. Binocular glaucomatous visual field loss and its impact on visual exploration--a supermarket study.

    Directory of Open Access Journals (Sweden)

    Katrin Sippel

    Full Text Available Advanced glaucomatous visual field loss may critically interfere with quality of life. The purpose of this study was to (i assess the impact of binocular glaucomatous visual field loss on a supermarket search task as an example of everyday living activities, (ii to identify factors influencing the performance, and (iii to investigate the related compensatory mechanisms. Ten patients with binocular glaucoma (GP, and ten healthy-sighted control subjects (GC were asked to collect twenty different products chosen randomly in two supermarket racks as quickly as possible. The task performance was rated as "passed" or "failed" with regard to the time per correctly collected item. Based on the performance of control subjects, the threshold value for failing the task was defined as μ+3σ (in seconds per correctly collected item. Eye movements were recorded by means of a mobile eye tracker. Eight out of ten patients with glaucoma and all control subjects passed the task. Patients who failed the task needed significantly longer time (111.47 s ±12.12 s to complete the task than patients who passed (64.45 s ±13.36 s, t-test, p < 0.001. Furthermore, patients who passed the task showed a significantly higher number of glances towards the visual field defect (VFD area than patients who failed (t-test, p < 0.05. According to these results, glaucoma patients with defects in the binocular visual field display on average longer search times in a naturalistic supermarket task. However, a considerable number of patients, who compensate by frequent glancing towards the VFD, showed successful task performance. Therefore, systematic exploration of the VFD area seems to be a "time-effective" compensatory mechanism during the present supermarket task.

  12. Three dimensional visualization of medical images

    International Nuclear Information System (INIS)

    Suto, Yasuzo

    1992-01-01

    Three dimensional visualization is a stereoscopic technique that allows the diagnosis and treatment of complicated anatomy site of the bone and organ. In this article, the current status and technical application of three dimensional visualization are introduced with special reference to X-ray CT and MRI. The surface display technique is the most common for three dimensional visualization, consisting of geometric model, voxel element, and stereographic composition techniques. Recent attention has been paid to display method of the content of the subject called as volume rendering, whereby information on the living body is provided accurately. The application of three dimensional visualization is described in terms of diagnostic imaging and surgical simulation. (N.K.)

  13. Iowa Flood Information System: Towards Integrated Data Management, Analysis and Visualization

    Science.gov (United States)

    Demir, I.; Krajewski, W. F.; Goska, R.; Mantilla, R.; Weber, L. J.; Young, N.

    2012-04-01

    The Iowa Flood Information System (IFIS) is a web-based platform developed by the Iowa Flood Center (IFC) to provide access to flood inundation maps, real-time flood conditions, flood forecasts both short-term and seasonal, flood-related data, information and interactive visualizations for communities in Iowa. The key element of the system's architecture is the notion of community. Locations of the communities, those near streams and rivers, define basin boundaries. The IFIS provides community-centric watershed and river characteristics, weather (rainfall) conditions, and streamflow data and visualization tools. Interactive interfaces allow access to inundation maps for different stage and return period values, and flooding scenarios with contributions from multiple rivers. Real-time and historical data of water levels, gauge heights, and rainfall conditions are available in the IFIS by streaming data from automated IFC bridge sensors, USGS stream gauges, NEXRAD radars, and NWS forecasts. Simple 2D and 3D interactive visualizations in the IFIS make the data more understandable to general public. Users are able to filter data sources for their communities and selected rivers. The data and information on IFIS is also accessible through web services and mobile applications. The IFIS is optimized for various browsers and screen sizes to provide access through multiple platforms including tablets and mobile devices. The IFIS includes a rainfall-runoff forecast model to provide a five-day flood risk estimate for around 500 communities in Iowa. Multiple view modes in the IFIS accommodate different user types from general public to researchers and decision makers by providing different level of tools and details. River view mode allows users to visualize data from multiple IFC bridge sensors and USGS stream gauges to follow flooding condition along a river. The IFIS will help communities make better-informed decisions on the occurrence of floods, and will alert communities

  14. A Free Program for Using and Teaching an Accessible Electronic Wayfinding Device

    Science.gov (United States)

    Greenberg, Maya Delgado; Kuns, Jerry

    2012-01-01

    Accessible Global Positioning Systems (GPS) are changing the way many people with visual impairments (that is, those who are blind or have low vision) travel. GPS provides real-time orientation information so that a traveler with a visual impairment can make informed decisions about path of travel and destination. Orientation and mobility (O&M)…

  15. Visualization of the lower cranial nerves by 3D-FIESTA

    International Nuclear Information System (INIS)

    Okumura, Yusuke; Suzuki, Masayuki; Takemura, Akihiro; Tsujii, Hideo; Kawahara, Kazuhiro; Matsuura, Yukihiro; Takada, Tadanori

    2005-01-01

    MR cisternography has been introduced for use in neuroradiology. This method is capable of visualizing tiny structures such as blood vessels and cranial nerves in the cerebrospinal fluid (CSF) space because of its superior contrast resolution. The cranial nerves and small vessels are shown as structures of low intensity surrounded by marked hyperintensity of the CSF. In the present study, we evaluated visualization of the lower cranial nerves (glossopharyngeal, vagus, and accessory) by the three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) sequence and multiplanar reformation (MPR) technique. The subjects were 8 men and 3 women, ranging in age from 21 to 76 years (average, 54 yeas). We examined the visualization of a total of 66 nerves in 11 subjects by 3D-FIESTA. The results were classified into four categories ranging from good visualization to non-visualization. In all cases, all glossopharyngeal and vagus nerves were identified to some extent, while accessory nerves were visualized either partially or entirely in only 16 cases. The total visualization rate was about 91%. In conclusion, 3D-FIESTA may be a useful method for visualization of the lower cranial nerves. (author)

  16. Posing for awareness: proprioception modulates access to visual consciousness in a continuous flash suppression task.

    Science.gov (United States)

    Salomon, Roy; Lim, Melanie; Herbelin, Bruno; Hesselmann, Guido; Blanke, Olaf

    2013-06-03

    The rules governing the selection of which sensory information reaches consciousness are yet unknown. Of our senses, vision is often considered to be the dominant sense, and the effects of bodily senses, such as proprioception, on visual consciousness are frequently overlooked. Here, we demonstrate that the position of the body influences visual consciousness. We induced perceptual suppression by using continuous flash suppression. Participants had to judge the orientation a target stimulus embedded in a task-irrelevant picture of a hand. The picture of the hand could either be congruent or incongruent with the participants' actual hand position. When the viewed and the real hand positions were congruent, perceptual suppression was broken more rapidly than during incongruent trials. Our findings provide the first evidence of a proprioceptive bias in visual consciousness, suggesting that proprioception not only influences the perception of one's own body and self-consciousness, but also visual consciousness.

  17. History and future of visual anthropology.

    Science.gov (United States)

    Svilicić, Niksa

    2011-03-01

    Visual recording of communication processes between communities or individuals by means of filming of photographing is of significant importance in anthropology, as it documents on site the specific features of various social communities in their encounter with the researcher. In terms of film industry, it is a sort of ethno-documentary pursuing originality and objectivity in recording the given subject, thus fulfilling the research mission. However, the potential of visual anthropology significantly exceeds the mere audiovisual recording of ethnologic realities. Modern methods of analysing and evaluating the role of visual anthropology suggest that it is a technical research service aimed at documenting the status quo. If the direction of proactive approach were taken, then the term ,visual anthropology' could be changed to ,anthropology of the visual,. This apparently cosmetic change of name is actually significantly more accurate, suggesting the denoted proactive swift in perceiving visual anthropology, where visual methods are employed to ,provoke< the reaction of an individual or of the community. In this way the "anthropology of the visual, is promoted to a new scientific sub-anthropological discipline.

  18. Subtitled video tutorials, an accessible teaching material

    Directory of Open Access Journals (Sweden)

    Luis Bengochea

    2012-11-01

    Full Text Available The use of short-lived audio-visual tutorials constitutes an educational resource very attractive for young students, widely familiar with this type of format similar to YouTube clips. Considered as "learning pills", these tutorials are intended to strengthen the understanding of complex concepts that because their dynamic nature can’t be represented through texts or diagrams. However, the inclusion of this type of content in eLearning platforms presents accessibility problems for students with visual or hearing disabilities. This paper describes this problem and shows the way in which a teacher could add captions and subtitles to their videos.

  19. Visualization of volumetric seismic data

    Science.gov (United States)

    Spickermann, Dela; Böttinger, Michael; Ashfaq Ahmed, Khawar; Gajewski, Dirk

    2015-04-01

    Mostly driven by demands of high quality subsurface imaging, highly specialized tools and methods have been developed to support the processing, visualization and interpretation of seismic data. 3D seismic data acquisition and 4D time-lapse seismic monitoring are well-established techniques in academia and industry, producing large amounts of data to be processed, visualized and interpreted. In this context, interactive 3D visualization methods proved to be valuable for the analysis of 3D seismic data cubes - especially for sedimentary environments with continuous horizons. In crystalline and hard rock environments, where hydraulic stimulation techniques may be applied to produce geothermal energy, interpretation of the seismic data is a more challenging problem. Instead of continuous reflection horizons, the imaging targets are often steep dipping faults, causing a lot of diffractions. Without further preprocessing these geological structures are often hidden behind the noise in the data. In this PICO presentation we will present a workflow consisting of data processing steps, which enhance the signal-to-noise ratio, followed by a visualization step based on the use the commercially available general purpose 3D visualization system Avizo. Specifically, we have used Avizo Earth, an extension to Avizo, which supports the import of seismic data in SEG-Y format and offers easy access to state-of-the-art 3D visualization methods at interactive frame rates, even for large seismic data cubes. In seismic interpretation using visualization, interactivity is a key requirement for understanding complex 3D structures. In order to enable an easy communication of the insights gained during the interactive visualization process, animations of the visualized data were created which support the spatial understanding of the data.

  20. Improved automated perimetry performance in elderly subjects after listening to Mozart.

    Science.gov (United States)

    Marques, Junia Cabral; Vanessa, Adriana Chaves Oliveira; Fiorelli, Macedo Batista; Kasahara, Niro

    2009-01-01

    To evaluate the performance of automated perimetry of elderly subjects naïve to AP after listening to a Mozart sonata. Automated perimetry (AP) is a psychophysical test used to assess visual fields in patients with neurological disorders and glaucoma. In a previous study, Fiorelli et al. showed that young subjects who listened to a Mozart sonata prior to undergoing AP performed better in terms of reliability than those who did not listen to the sonata. Fifty-two AP-naïve, normal subjects underwent Automated perimetry (SITA 24-2). The study group (25 subjects) underwent AP after listening to Mozart's Sonata for Two Pianos in D Major, and the control group (27 subjects) underwent Automated perimetry without prior exposure to the music. The study group had significantly lower false negative rates and a lower visual field reliability score than the controls (P=0.04 and P=0.04, respectively). The test time was shorter for the study group (P=0.03). This study shows that elderly subjects, when exposed to the Mozart sonata immediately before AP testing, have lower false negative rates and lower visual field reliability scores when compared with an age- and gender-matched control group. Our results differ from those of Fiorelli et al. who found lower false positive rates and less fixation loss in addition to lower false negative rates. Listening to a Mozart sonata seems to improve automated perimetry reliability in elderly subjects.

  1. [Physiological mechanisms of the etiology of visual fatigue during work involving visual stress].

    Science.gov (United States)

    Korniushina, T A

    2000-01-01

    Physiological parameters of vision were studied in three professional groups (a total of 1204 subjects): microscope operators, subjects working with magnifying glasses, and computer users. General and specific features of visual system fatigue formation were identified. Because of complete (in microscope operators) or partial (in subjects working with magnifying glasses and display users) "deprivation" of accommodation, these subjects develop early presbyopia (at the age of 30-35 years). In microscope operators long strain of accommodation system leads to professional myopia, while display users develop pseudomyopia. The highest overstrain is observed after 4 years of work in microscope operators, after 5 years in magnifying glass users, and after 6 years in computer users.

  2. A global workspace model for phenomenal and access consciousness.

    Science.gov (United States)

    Raffone, Antonino; Pantani, Martina

    2010-06-01

    Both the global workspace theory and Block's distinction between phenomenal and access consciousness, are central in the current debates about consciousness and the neural correlates of consciousness. In this article, a unifying global workspace model for phenomenal and access consciousness is proposed. In the model, recurrent neural interactions take place in distinct yet interacting access and phenomenal brain loops. The effectiveness of feedback signaling onto sensory cortical maps is emphasized for the neural correlates of phenomenal consciousness. Two forms of top-down attention, attention for perception and attention for access, play differential roles for phenomenal and access consciousness. The model is implemented in a neural network form, with the simulation of single and multiple visual object processing, and of the attentional blink. 2010 Elsevier Inc. All rights reserved.

  3. Visual field defects after temporal lobe resection for epilepsy.

    Science.gov (United States)

    Steensberg, Alvilda T; Olsen, Ane Sophie; Litman, Minna; Jespersen, Bo; Kolko, Miriam; Pinborg, Lars H

    2018-01-01

    To determine visual field defects (VFDs) using methods of varying complexity and compare results with subjective symptoms in a population of newly operated temporal lobe epilepsy patients. Forty patients were included in the study. Two patients failed to perform VFD testing. Humphrey Field Analyzer (HFA) perimetry was used as the gold standard test to detect VFDs. All patients performed a web-based visual field test called Damato Multifixation Campimetry Online (DMCO). A bedside confrontation visual field examination ad modum Donders was extracted from the medical records in 27/38 patients. All participants had a consultation by an ophthalmologist. A questionnaire described the subjective complaints. A VFD in the upper quadrant was demonstrated with HFA in 29 (76%) of the 38 patients after surgery. In 27 patients tested ad modum Donders, the sensitivity of detecting a VFD was 13%. Eight patients (21%) had a severe VFD similar to a quadrant anopia, thus, questioning their permission to drive a car. In this group of patients, a VFD was demonstrated in one of five (sensitivity=20%) ad modum Donders and in seven of eight (sensitivity=88%) with DMCO. Subjective symptoms were only reported by 28% of the patients with a VFD and in two of eight (sensitivity=25%) with a severe VFD. Most patients (86%) considered VFD information mandatory. VFD continue to be a frequent adverse event after epilepsy surgery in the medial temporal lobe and may affect the permission to drive a car in at least one in five patients. Subjective symptoms and bedside visual field testing ad modum Donders are not sensitive to detect even a severe VFD. Newly developed web-based visual field test methods appear sensitive to detect a severe VFD but perimetry remains the golden standard for determining if visual standards for driving is fulfilled. Patients consider VFD information as mandatory. Copyright © 2017. Published by Elsevier Ltd.

  4. Beyond access: a case study on the intersection between accessibility, sustainability, and universal design.

    Science.gov (United States)

    Gossett, Andrea; Mirza, Mansha; Barnds, Ann Kathleen; Feidt, Daisy

    2009-11-01

    A growing emphasis has been placed on providing equal opportunities for all people, particularly people with disabilities, to support participation. Barriers to participation are represented in part by physical space restrictions. This article explores the decision-making process during the construction of a new office building housing a disability-rights organization. The building project featured in this study was developed on the principles of universal design, maximal accessibility, and sustainability to support access and participation. A qualitative case study approach was used involving collection of data through in-depth interviews with key decision-makers; non-participant observations at design meetings; and on-site tours. Qualitative thematic analysis along with the development of a classification system was used to understand specific building elements and the relevant decision processes from which they resulted. Recording and analyzing the design process revealed several key issues including grassroots involvement of stakeholders; interaction between universal design and sustainable design; addressing diversity through flexibility and universality; and segregationist accessibility versus universal design. This case study revealed complex interactions between accessibility, universal design, and sustainability. Two visual models were proposed to understand and analyze these complexities.

  5. A new multimodal interactive way of subjective scoring of 3D video quality of experience

    Science.gov (United States)

    Kim, Taewan; Lee, Kwanghyun; Lee, Sanghoon; Bovik, Alan C.

    2014-03-01

    People that watch today's 3D visual programs, such as 3D cinema, 3D TV and 3D games, experience wide and dynamically varying ranges of 3D visual immersion and 3D quality of experience (QoE). It is necessary to be able to deploy reliable methodologies that measure each viewers subjective experience. We propose a new methodology that we call Multimodal Interactive Continuous Scoring of Quality (MICSQ). MICSQ is composed of a device interaction process between the 3D display and a separate device (PC, tablet, etc.) used as an assessment tool, and a human interaction process between the subject(s) and the device. The scoring process is multimodal, using aural and tactile cues to help engage and focus the subject(s) on their tasks. Moreover, the wireless device interaction process makes it possible for multiple subjects to assess 3D QoE simultaneously in a large space such as a movie theater, and at di®erent visual angles and distances.

  6. Building visual identity of scientific and research units and the role of visualization in cooperation with business

    Directory of Open Access Journals (Sweden)

    Alfreda Kamińska

    2014-12-01

    Full Text Available The need for commercialization of scientific research leads to the necessity of changing the orientation of scientific-research units to marketing orientation, which is characterized by, among others, conducting research aimed at learning the clients’ needs and building better communication with the recipients. What is an important element of a unit’s marketing communication is its visual identity system, which the recipients use to build their opinion and their picture of the unit. The goal of this article is an attempt to define the key rules of designing visual identity of scientific and research institutions, as well as presenting the role of visualization in their cooperation with business. In the article the notions of image, identity, corporate identity and visual identity are subject to analysis. The article also presents the significance of visualization in the functioning of research and scientific units, elements of visual identity system and the rules of designing visual identity of scientific and research institutions. An analysis of chosen research-scientific units was carried out with regard to visualization.

  7. The Efficacy of Haptic Simulations to Teach Students with Visual Impairments about Temperature and Pressure

    Science.gov (United States)

    Jones, M. Gail; Childers, Gina; Emig, Brandon; Chevrier, Joël; Tan, Hong; Stevens, Vanessa; List, Jonathan

    2014-01-01

    Traditional science instruction is typically reliant on visual modes of learning, such as textbooks and graphs. Furthermore, since science instruction is often heavily dependent upon visual cues, students with visual impairment often do not have access to the same educational opportunities in most science classes (Jones, Minogue, Oppewal, Cook,…

  8. MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject.

    Science.gov (United States)

    Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe; Saridis, George A; Gjedde, Albert; Ptito, Maurice; Kupers, Ron

    2013-01-01

    Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA) 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong, and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI) revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

  9. High-performance execution of psychophysical tasks with complex visual stimuli in MATLAB

    Science.gov (United States)

    Asaad, Wael F.; Santhanam, Navaneethan; McClellan, Steven

    2013-01-01

    Behavioral, psychological, and physiological experiments often require the ability to present sensory stimuli, monitor and record subjects' responses, interface with a wide range of devices, and precisely control the timing of events within a behavioral task. Here, we describe our recent progress developing an accessible and full-featured software system for controlling such studies using the MATLAB environment. Compared with earlier reports on this software, key new features have been implemented to allow the presentation of more complex visual stimuli, increase temporal precision, and enhance user interaction. These features greatly improve the performance of the system and broaden its applicability to a wider range of possible experiments. This report describes these new features and improvements, current limitations, and quantifies the performance of the system in a real-world experimental setting. PMID:23034363

  10. The effects of acute bout of cycling on auditory & visual reaction times.

    Science.gov (United States)

    Ashnagar, Zinat; Shadmehr, Azadeh; Jalaei, Shohreh

    2015-04-01

    The purpose of this study was to investigate the effects of an acute bout of cycling exercise on auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction time. 29 subjects were randomly divided into experimental and control groups. The subjects of the experimental group carried out a single bout of submaximal cycling exercise. The auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction times were measured before and after the exercise session. The reaction time tests were taken from the subjects by using Speed Anticipation and Reaction Tester (SART) software. In the control group, the reaction time tests were performed by the subjects with an interval of 30 min. In the experimental group, the percentage changes of mean auditory choice and complex choice reaction time values were significantly decreased in comparison with the control group (P visual choice and complex choice reaction times were decreased after the exercise, the changes were not significant (P > 0.05). An acute bout of cycling exercise improved the speed of auditory and visual reaction times in healthy young females. However, these positive changes were significantly observed only in the auditory reaction time tests in comparison with the control group. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Teach yourself visually iPad

    CERN Document Server

    Hart-Davis, Guy

    2013-01-01

    Fully updated coverage on the latest iPad and iPad mini! As the amazing iPad continues to evolve, so does this invaluable visual guide. Bestselling veteran author Guy Hart-Davis gets you up to date on the latest generation of the iPad, the new iPad Air, as well as the iPad mini with his clear step-by-step, image-driven guidance that is perfectly geared towards those who learn best with visual assistance. You'll get all the latest information for accessing and downloading books, apps, music, and video content as well as sending photos and e-mails, syncing with other devices and services, and

  12. Accessibility in e-government portals of the Judiciary

    Directory of Open Access Journals (Sweden)

    Mariana Pessini Mezzaroba

    2016-05-01

    Full Text Available This article deals with an analysis of the application of Macedo accessibility guidelines (2010 for the publication of texts on the Web. In this paper, e-government portals were observed, particularly the judiciary, using the Supreme Court site Federal (STF, to verify whether the available material allows people with some kind of visual disability to access it and become aware of its contents. We also used the model of accessibility in Electronic Government eMag, established by the Federal Government, through Decree n. 03 of 07 May 2007.It were also developed the graphical representation of synthesis (RGS addressed the issue. The analysis was performed from the application of e-government accessibility evaluator ASES (Appraiser and accessibility Simulator Sites, combining their results with the textual guidelines already mentioned. After analyzing the results, it shows a table with errors and recommendations to the portal.

  13. Visual-perceptual mismatch in robotic surgery.

    Science.gov (United States)

    Abiri, Ahmad; Tao, Anna; LaRocca, Meg; Guan, Xingmin; Askari, Syed J; Bisley, James W; Dutson, Erik P; Grundfest, Warren S

    2017-08-01

    The principal objective of the experiment was to analyze the effects of the clutch operation of robotic surgical systems on the performance of the operator. The relative coordinate system introduced by the clutch operation can introduce a visual-perceptual mismatch which can potentially have negative impact on a surgeon's performance. We also assess the impact of the introduction of additional tactile sensory information on reducing the impact of visual-perceptual mismatch on the performance of the operator. We asked 45 novice subjects to complete peg transfers using the da Vinci IS 1200 system with grasper-mounted, normal force sensors. The task involves picking up a peg with one of the robotic arms, passing it to the other arm, and then placing it on the opposite side of the view. Subjects were divided into three groups: aligned group (no mismatch), the misaligned group (10 cm z axis mismatch), and the haptics-misaligned group (haptic feedback and z axis mismatch). Each subject performed the task five times, during which the grip force, time of completion, and number of faults were recorded. Compared to the subjects that performed the tasks using a properly aligned controller/arm configuration, subjects with a single-axis misalignment showed significantly more peg drops (p = 0.011) and longer time to completion (p sensors showed no difference between the different groups. The visual-perceptual mismatch created by the misalignment of the robotic controls relative to the robotic arms has a negative impact on the operator of a robotic surgical system. Introduction of other sensory information and haptic feedback systems can help in potentially reducing this effect.

  14. Dynamic Interactions for Network Visualization and Simulation

    Science.gov (United States)

    2009-03-01

    projects.htm, Site accessed January 5, 2009. 12. John S. Weir, Major, USAF, Mediated User-Simulator Interactive Command with Visualization ( MUSIC -V). Master’s...Computing Sciences in Colleges, December 2005). 14. Enrique Campos -Nanez, “nscript user manual,” Department of System Engineer- ing University of

  15. Web-based Visual Analytics for Extreme Scale Climate Science

    Energy Technology Data Exchange (ETDEWEB)

    Steed, Chad A [ORNL; Evans, Katherine J [ORNL; Harney, John F [ORNL; Jewell, Brian C [ORNL; Shipman, Galen M [ORNL; Smith, Brian E [ORNL; Thornton, Peter E [ORNL; Williams, Dean N. [Lawrence Livermore National Laboratory (LLNL)

    2014-01-01

    In this paper, we introduce a Web-based visual analytics framework for democratizing advanced visualization and analysis capabilities pertinent to large-scale earth system simulations. We address significant limitations of present climate data analysis tools such as tightly coupled dependencies, ineffi- cient data movements, complex user interfaces, and static visualizations. Our Web-based visual analytics framework removes critical barriers to the widespread accessibility and adoption of advanced scientific techniques. Using distributed connections to back-end diagnostics, we minimize data movements and leverage HPC platforms. We also mitigate system dependency issues by employing a RESTful interface. Our framework embraces the visual analytics paradigm via new visual navigation techniques for hierarchical parameter spaces, multi-scale representations, and interactive spatio-temporal data mining methods that retain details. Although generalizable to other science domains, the current work focuses on improving exploratory analysis of large-scale Community Land Model (CLM) and Community Atmosphere Model (CAM) simulations.

  16. Introduction to the special issue on visual aesthetics

    Directory of Open Access Journals (Sweden)

    Marković Slobodan

    2017-01-01

    Full Text Available Visual aesthetics encompasses the studies of the relationship between vision and various aesthetic phenomena - from the beauty ratings of simple visual patterns to the appreciation of visual art, from the preference for natural objects and scenes to the preference for products of human creativity, from the aesthetic effects of culture to the aesthetic effects of biology, from the universal aesthetic sensitivity to the individual differences in taste, and so on. In this special issue ten papers reported the most recent studies on very different subjects related to visual aesthetics.

  17. Visualization of disciplinary profiles: Enhanced science overlay maps

    NARCIS (Netherlands)

    Carley, S.; Porter, A.L.; Rafols, I.; Leydesdorff, L.

    Purpose The purpose of this study is to modernize previous work on science overlay maps by updating the underlying citation matrix, generating new clusters of scientific disciplines, enhancing visualizations, and providing more accessible means for analysts to generate their own maps.

  18. Comparison of Congruence Judgment and Auditory Localization Tasks for Assessing the Spatial Limits of Visual Capture

    Science.gov (United States)

    Bosen, Adam K.; Fleming, Justin T.; Brown, Sarah E.; Allen, Paul D.; O'Neill, William E.; Paige, Gary D.

    2016-01-01

    Vision typically has better spatial accuracy and precision than audition, and as a result often captures auditory spatial perception when visual and auditory cues are presented together. One determinant of visual capture is the amount of spatial disparity between auditory and visual cues: when disparity is small visual capture is likely to occur, and when disparity is large visual capture is unlikely. Previous experiments have used two methods to probe how visual capture varies with spatial disparity. First, congruence judgment assesses perceived unity between cues by having subjects report whether or not auditory and visual targets came from the same location. Second, auditory localization assesses the graded influence of vision on auditory spatial perception by having subjects point to the remembered location of an auditory target presented with a visual target. Previous research has shown that when both tasks are performed concurrently they produce similar measures of visual capture, but this may not hold when tasks are performed independently. Here, subjects alternated between tasks independently across three sessions. A Bayesian inference model of visual capture was used to estimate perceptual parameters for each session, which were compared across tasks. Results demonstrated that the range of audio-visual disparities over which visual capture was likely to occur were narrower in auditory localization than in congruence judgment, which the model indicates was caused by subjects adjusting their prior expectation that targets originated from the same location in a task-dependent manner. PMID:27815630

  19. Tactile band : accessing gaze signals from the sighted in face-to-face communication

    NARCIS (Netherlands)

    Qiu, S.; Rauterberg, G.W.M.; Hu, J.

    2016-01-01

    Gaze signals, frequently used by the sighted in social interactions as visual cues, are hardly accessible for low-vision and blind people. A concept is proposed to help the blind people access and react to gaze signals in face-to-face communication. 20 blind and low-vision participants were

  20. Measuring Visual Closeness of 3-D Models

    KAUST Repository

    Gollaz Morales, Jose Alejandro

    2012-09-01

    Measuring visual closeness of 3-D models is an important issue for different problems and there is still no standardized metric or algorithm to do it. The normal of a surface plays a vital role in the shading of a 3-D object. Motivated by this, we developed two applications to measure visualcloseness, introducing normal difference as a parameter in a weighted metric in Metro’s sampling approach to obtain the maximum and mean distance between 3-D models using 3-D and 6-D correspondence search structures. A visual closeness metric should provide accurate information on what the human observers would perceive as visually close objects. We performed a validation study with a group of people to evaluate the correlation of our metrics with subjective perception. The results were positive since the metrics predicted the subjective rankings more accurately than the Hausdorff distance.

  1. Changes in brain morphology in albinism reflect reduced visual acuity.

    Science.gov (United States)

    Bridge, Holly; von dem Hagen, Elisabeth A H; Davies, George; Chambers, Claire; Gouws, Andre; Hoffmann, Michael; Morland, Antony B

    2014-07-01

    Albinism, in humans and many animal species, has a major impact on the visual system, leading to reduced acuity, lack of binocular function and nystagmus. In addition to the lack of a foveal pit, there is a disruption to the routing of the nerve fibers crossing at the optic chiasm, resulting in excessive crossing of fibers to the contralateral hemisphere. However, very little is known about the effect of this misrouting on the structure of the post-chiasmatic visual pathway, and the occipital lobes in particular. Whole-brain analyses of cortical thickness in a large cohort of subjects with albinism showed an increase in cortical thickness, relative to control subjects, particularly in posterior V1, corresponding to the foveal representation. Furthermore, mean cortical thickness across entire V1 was significantly greater in these subjects compared to controls and negatively correlated with visual acuity in albinism. Additionally, the group with albinism showed decreased gyrification in the left ventral occipital lobe. While the increase in cortical thickness in V1, also found in congenitally blind subjects, has been interpreted to reflect a lack of pruning, the decreased gyrification in the ventral extrastriate cortex may reflect the reduced input to the foveal regions of the ventral visual stream. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Increasing Access to Archival Records in Library Online Public Access Catalogs.

    Science.gov (United States)

    Gilmore, Matthew B.

    1988-01-01

    Looks at the use of online public access catalogs, the utility of subject and call-number searching, and possible archival applications. The Wallace Archives at the Claremont Colleges is used as an example of the availability of bibliographic descriptions of multiformat archival materials through the library catalog. Sample records and searches…

  3. Access to Point-of-Care Tests Reduces the Prescription of Antibiotics Among Antibiotic-Requesting Subjects With Respiratory Tract Infections

    DEFF Research Database (Denmark)

    Llor, Carl; Bjerrum, Lars; Munck, Anders

    2014-01-01

    BACKGROUND: General practitioners (GPs) often feel uncomfortable when patients request an antibiotic when there is likely little benefit. This study evaluates the effect of access to point-of-care tests on decreasing the prescription of antibiotics in respiratory tract infections in subjects who...... explicitly requested an antibiotic prescription. METHODS: Spanish GPs registered all cases of respiratory tract infections over a 3-week period before and after an intervention undertaken in 2008 and 2009. Patients with acute sinusitis, pneumonia, and exacerbations of COPD were excluded. Two types...... requesting antibiotics received a prescription before and 60% after the intervention, without statistical differences being observed. In the group of GPs assigned to the full intervention group, the percentages were 55.1% and 36.2%, respectively, with a difference of 18.9% (95% CI: 6.4%-30.6%, P

  4. Perceived importance and difficulty of online activities among visually impaired persons in Nigeria.

    Science.gov (United States)

    Okonji, Patrick Emeka; Okiki, Olatokunbo Christopher; Ogwezzy, Darlington

    2018-03-26

    This study investigated perceived relevance of and difficulties in access to day-to-day online activities among visually impaired computer users who used screen readers. The 98 participants in the study were grouped into visually impaired adults (VIA; aged 20-59, n = 60) and visually impaired older adults (VIOA; aged 60 and over, n = 38). Data were collected in structured interview questionnaires with Likert scales exploring ratings of perceived importance and difficulty of access to eleven (11) online platforms of various internet activities. Analyses revealed that the two groups did not differ significantly in ratings of perceived importance of 4 major online activities, namely; Sending or reading email (p = 0.5224), Online banking (p = 0.2833), Online shopping (p = 0.1829), and Health information seeking (p = 0.1414). The topmost rated activity of priority among both groups was sending and reading emails. Findings also show that, apart from sending and reading emails, activities rated as important were mostly perceived as difficult to access. The implications of the study for inclusive design and strategies and/or interventions to encourage uptake of internet use among the visually impaired population are discussed.

  5. VISUAL ABILITY IN AMBLYOPIC CHILDREN COMPARED TO CHILDREN WITH NORMAL VISUAL ACUITY

    Directory of Open Access Journals (Sweden)

    Zorica Tončić

    2016-03-01

    Full Text Available Vision rehabilitation in adults with low vision, even in children, is achieved with special devices, called low vision aids, LVA. The aim of the study is to determine the degree of visual function in amblyopic children and daily activities that are best related to those of normally sighted peers with normal visual acuity. The subjects were divided into two groups, matched 1:1 by age and gender: the first group consisted of 19 amblyopic children, and the second one consisted of 19 children with normal visual acuity. The questionnaire used to assess visual ability was Cardiff Visual Ability Questionnaire for Children (CVAQC, a reliable instrument for measuring visual ability in children with low vision. The study was conducted in the only rehabilitation center for amblyopic children in this region, so this is also a pioneer study. The overall result of CVAQC in amblyopic children was 1.287 log vs.-2.956, representing statistically significantly poorer visual ability in comparison to peers without vision deficit (p˂0.005. Amblyopic children function best in entertainment activities, especially in listening music (-2.31 log; as for sport, these children report swimming to be their favourite activity (-0.99 log. In the field of education they show best results in language acquisition (-0.79 log and the worst in mathematics (3.13 log. The greatest problem is reading small print texts books (2.61 log. Low vision children have poorer result of visual function in comparison to their peers with normal visual acuity. A precise deficit assessment in the most important spheres of life can be determined by using the questionnaires, so the rehabilitation can be rightly chosen.

  6. Subjective Perception of Visual Distortions or Scotomas in Individuals with Retinitis Pigmentosa

    Science.gov (United States)

    Wittich, Walter; Watanabe, Donald H.; Kapusta, Michael A.; Overbury, Olga

    2011-01-01

    It is often assumed that persons who develop ocular disease have some form of visual experience that makes them aware of their deficits. However, in the case of peripheral field loss or decreasing vision in dim lighting, as in retinitis pigmentosa, for example, symptoms are more obscure and may not be as easily identified by the persons who have…

  7. Visual performance with sport-tinted contact lenses in natural sunlight.

    Science.gov (United States)

    Erickson, Graham B; Horn, Fraser C; Barney, Tyler; Pexton, Brett; Baird, Richard Y

    2009-05-01

    The use of tinted and clear contact lenses (CLs) in all aspects of life is becoming a more popular occurrence, particularly in athletic activities. This study broadens previous research regarding performance-tinted CLs and their effects on measures of visual performance. Thirty-three subjects (14 male, 19 female) were fitted with clear B&L Optima 38, 50% visible light transmission Amber and 36% visible light transmission Gray-Green Nike Maxsight CLs in an individualized randomized sequence. Subjects were dark-adapted with welding goggles before testing and in between subtests involving a Bailey-Lovie chart and the Haynes Distance Rock test. The sequence of testing was repeated for each lens modality. The Amber and Gray-Green lenses enabled subjects to recover vision faster in bright sunlight compared with clear lenses. Also, subjects were able to achieve better visual recognition in bright sunlight when compared with clear lenses. Additionally, the lenses allowed the subjects to alternate fixation between a bright and shaded target at a more rapid rate in bright sunlight as compared with clear lenses. Subjects preferred both the Amber and Gray-Green lenses over clear lenses in the bright and shadowed target conditions. The results of the current study show that Maxsight Amber and Gray-Green lenses provide better contrast discrimination in bright sunlight, better contrast discrimination when alternating between bright and shaded target conditions, better speed of visual recovery in bright sunlight, and better overall visual performance in bright and shaded target conditions compared with clear lenses.

  8. Higher risk of probable mental emotional disorder in low or severe vision subjects

    Directory of Open Access Journals (Sweden)

    Lutfah Rif’ati

    2012-07-01

    health problem priority in Indonesia. This paper presents an assessment of severe visual impairments related to the risk of MED. Methods: This paper assessed a part of Basic Health Research (Riskesdas 2007 data. For this assessment, subjects 15 years old or more had their visual acuity measured using the Snellen chart and their mental health status determined using the Self Reporting Questionnaire (SRQ 20. A subject was considered to have probable MED if the subject had a total score of 6 or more on the SRQ. Based on the measure of visual acuity, visual acuity was divided into 3 categories: normal/mild (20/20 to 20/60; low vision (less than 20/60 to 3/60; and blind (less than 3/60 to 0/0. Results: Among 972,989 subjects, 554,886 were aged 15 years or older. 11.4% of the subjects had probable MED. The prevalence of low vision and blindness was 5.1% and 0.9%, respectively. Compared to subjects with normal or mild visual impairments, subjects with low vision had a 74% increased risk for probable MED [adjusted relative risk (RRa=1,75; 95% confidence interval (CI=1,71-1,79].  Blind subjects had a 2.7-fold risk to be probable MED (RRa=2.69; 95% CI=2.60-2.78] compared to subjects with normal or mild visual impairments. Conclusion: Visual impairment severity increased probable MED risk. Therefore, visual impairment subjects need more attention on probable MED. (Health Science Indones 2011;2:9-13

  9. Functional magnetic resonance imaging by visual stimulation

    International Nuclear Information System (INIS)

    Nishimura, Yukiko; Negoro, Kiyoshi; Morimatsu, Mitsunori; Hashida, Masahiro

    1996-01-01

    We evaluated functional magnetic resonance images obtained in 8 healthy subjects in response to visual stimulation using a conventional clinical magnetic resonance imaging system with multi-slice spin-echo echo planar imaging. Activation in the visual cortex was clearly demonstrated by the multi-slice experiment with a task-related change in signal intensity. In addition to the primary visual cortex, other areas were also activated by a complicated visual task. Multi-slice spin-echo echo planar imaging offers high temporal resolution and allows the three-dimensional analysis of brain function. Functional magnetic resonance imaging provides a useful noninvasive method of mapping brain function. (author)

  10. Pathview Web: user friendly pathway visualization and data integration.

    Science.gov (United States)

    Luo, Weijun; Pant, Gaurav; Bhavnasi, Yeshvant K; Blanchard, Steven G; Brouwer, Cory

    2017-07-03

    Pathway analysis is widely used in omics studies. Pathway-based data integration and visualization is a critical component of the analysis. To address this need, we recently developed a novel R package called Pathview. Pathview maps, integrates and renders a large variety of biological data onto molecular pathway graphs. Here we developed the Pathview Web server, as to make pathway visualization and data integration accessible to all scientists, including those without the special computing skills or resources. Pathview Web features an intuitive graphical web interface and a user centered design. The server not only expands the core functions of Pathview, but also provides many useful features not available in the offline R package. Importantly, the server presents a comprehensive workflow for both regular and integrated pathway analysis of multiple omics data. In addition, the server also provides a RESTful API for programmatic access and conveniently integration in third-party software or workflows. Pathview Web is openly and freely accessible at https://pathview.uncc.edu/. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  11. Interactions between attention, context and learning in primary visual cortex.

    Science.gov (United States)

    Gilbert, C; Ito, M; Kapadia, M; Westheimer, G

    2000-01-01

    Attention in early visual processing engages the higher order, context dependent properties of neurons. Even at the earliest stages of visual cortical processing neurons play a role in intermediate level vision - contour integration and surface segmentation. The contextual influences mediating this process may be derived from long range connections within primary visual cortex (V1). These influences are subject to perceptual learning, and are strongly modulated by visuospatial attention, which is itself a learning dependent process. The attentional influences may involve interactions between feedback and horizontal connections in V1. V1 is therefore a dynamic and active processor, subject to top-down influences.

  12. The Impairing Effect of Mental Fatigue on Visual Sustained Attention under Monotonous Multi-Object Visual Attention Task in Long Durations: An Event-Related Potential Based Study.

    Directory of Open Access Journals (Sweden)

    Zizheng Guo

    Full Text Available The impairing effects of mental fatigue on visual sustained attention were assessed by event-related potentials (ERPs. Subjects performed a dual visual task, which includes a continuous tracking task (primary task and a random signal detection task (secondary task, for 63 minutes nonstop in order to elicit ERPs. In this period, the data such as subjective levels of mental fatigue, behavioral performance measures, and electroencephalograms were recorded for each subject. Comparing data from the first interval (0-25 min to that of the second, the following phenomena were observed: the subjective fatigue ratings increased with time, which indicates that performing the tasks leads to increase in mental fatigue levels; reaction times prolonged and accuracy rates decreased in the second interval, which indicates that subjects' sustained attention decreased.; In the ERP data, the P3 amplitudes elicited by the random signals decreased, while the P3 latencies increased in the second interval. These results suggest that mental fatigue can modulate the higher-level cognitive processes, in terms of less attentional resources allocated to the random stimuli, which leads to decreased speed in information evaluating and decision making against the stimuli. These findings provide new insights into the question that how mental fatigue affects visual sustained attention and, therefore, can help to design countermeasures to prevent accidents caused by low visual sustained attention.

  13. Fourier power, subjective distance, and object categories all provide plausible models of BOLD responses in scene-selective visual areas

    Science.gov (United States)

    Lescroart, Mark D.; Stansbury, Dustin E.; Gallant, Jack L.

    2015-01-01

    Perception of natural visual scenes activates several functional areas in the human brain, including the Parahippocampal Place Area (PPA), Retrosplenial Complex (RSC), and the Occipital Place Area (OPA). It is currently unclear what specific scene-related features are represented in these areas. Previous studies have suggested that PPA, RSC, and/or OPA might represent at least three qualitatively different classes of features: (1) 2D features related to Fourier power; (2) 3D spatial features such as the distance to objects in a scene; or (3) abstract features such as the categories of objects in a scene. To determine which of these hypotheses best describes the visual representation in scene-selective areas, we applied voxel-wise modeling (VM) to BOLD fMRI responses elicited by a set of 1386 images of natural scenes. VM provides an efficient method for testing competing hypotheses by comparing predictions of brain activity based on encoding models that instantiate each hypothesis. Here we evaluated three different encoding models that instantiate each of the three hypotheses listed above. We used linear regression to fit each encoding model to the fMRI data recorded from each voxel, and we evaluated each fit model by estimating the amount of variance it predicted in a withheld portion of the data set. We found that voxel-wise models based on Fourier power or the subjective distance to objects in each scene predicted much of the variance predicted by a model based on object categories. Furthermore, the response variance explained by these three models is largely shared, and the individual models explain little unique variance in responses. Based on an evaluation of previous studies and the data we present here, we conclude that there is currently no good basis to favor any one of the three alternative hypotheses about visual representation in scene-selective areas. We offer suggestions for further studies that may help resolve this issue. PMID:26594164

  14. Development of a Web-Based Visualization Platform for Climate Research Using Google Earth

    Science.gov (United States)

    Sun, Xiaojuan; Shen, Suhung; Leptoukh, Gregory G.; Wang, Panxing; Di, Liping; Lu, Mingyue

    2011-01-01

    Recently, it has become easier to access climate data from satellites, ground measurements, and models from various data centers, However, searching. accessing, and prc(essing heterogeneous data from different sources are very tim -consuming tasks. There is lack of a comprehensive visual platform to acquire distributed and heterogeneous scientific data and to render processed images from a single accessing point for climate studies. This paper. documents the design and implementation of a Web-based visual, interoperable, and scalable platform that is able to access climatological fields from models, satellites, and ground stations from a number of data sources using Google Earth (GE) as a common graphical interface. The development is based on the TCP/IP protocol and various data sharing open sources, such as OPeNDAP, GDS, Web Processing Service (WPS), and Web Mapping Service (WMS). The visualization capability of integrating various measurements into cE extends dramatically the awareness and visibility of scientific results. Using embedded geographic information in the GE, the designed system improves our understanding of the relationships of different elements in a four dimensional domain. The system enables easy and convenient synergistic research on a virtual platform for professionals and the general public, gr$tly advancing global data sharing and scientific research collaboration.

  15. Crisis in Cataloging Revisited: The Year's Work in Subject Analysis, 1990.

    Science.gov (United States)

    Young, James Bradford

    1991-01-01

    Reviews the 1990 literature that concerns subject analysis. Issues addressed include subject cataloging, including Library of Congress Subject Headings (LCSH); classification, including Dewey Decimal Classification (DDC), Library of Congress Classification, and classification in online systems; subject access, including the online use of…

  16. The effectiveness of multimedia visual perceptual training groups for the preschool children with developmental delay.

    Science.gov (United States)

    Chen, Yi-Nan; Lin, Chin-Kai; Wei, Ta-Sen; Liu, Chi-Hsin; Wuang, Yee-Pay

    2013-12-01

    This study compared the effectiveness of three approaches to improving visual perception among preschool children 4-6 years old with developmental delays: multimedia visual perceptual group training, multimedia visual perceptual individual training, and paper visual perceptual group training. A control group received no special training. This study employed a pretest-posttest control group of true experimental design. A total of 64 children 4-6 years old with developmental delays were randomized into four groups: (1) multimedia visual perceptual group training (15 subjects); (2) multimedia visual perceptual individual training group (15 subjects); paper visual perceptual group training (19 subjects); and (4) a control group (15 subjects) with no visual perceptual training. Forty minute training sessions were conducted once a week for 14 weeks. The Test of Visual Perception Skills, third edition, was used to evaluate the effectiveness of the intervention. Paired-samples t-test showed significant differences pre- and post-test among the three groups, but no significant difference was found between the pre-test and post-test scores among the control group. ANOVA results showed significant differences in improvement levels among the four study groups. Scheffe post hoc test results showed significant differences between: group 1 and group 2; group 1 and group 3; group 1 and the control group; and group 2 and the control group. No significant differences were reported between group 2 and group 3, and group 3 and the control group. The results showed all three therapeutic programs produced significant differences between pretest and posttest scores. The training effect on the multimedia visual perceptual group program and the individual program was greater than the developmental effect Both the multimedia visual perceptual group training program and the multimedia visual perceptual individual training program produced significant effects on visual perception. The

  17. Adaptive Gaze Strategies for Locomotion with Constricted Visual Field

    Directory of Open Access Journals (Sweden)

    Colas N. Authié

    2017-07-01

    Full Text Available In retinitis pigmentosa (RP, loss of peripheral visual field accounts for most difficulties encountered in visuo-motor coordination during locomotion. The purpose of this study was to accurately assess the impact of peripheral visual field loss on gaze strategies during locomotion, and identify compensatory mechanisms. Nine RP subjects presenting a central visual field limited to 10–25° in diameter, and nine healthy subjects were asked to walk in one of three directions—straight ahead to a visual target, leftward and rightward through a door frame, with or without obstacle on the way. Whole body kinematics were recorded by motion capture, and gaze direction in space was reconstructed using an eye-tracker. Changes in gaze strategies were identified in RP subjects, including extensive exploration prior to walking, frequent fixations of the ground (even knowing no obstacle was present, of door edges, essentially of the proximal one, of obstacle edge/corner, and alternating door edges fixations when approaching the door. This was associated with more frequent, sometimes larger rapid-eye-movements, larger movements, and forward tilting of the head. Despite the visual handicap, the trajectory geometry was identical between groups, with a small decrease in walking speed in RPs. These findings identify the adaptive changes in sensory-motor coordination, in order to ensure visual awareness of the surrounding, detect changes in spatial configuration, collect information for self-motion, update the postural reference frame, and update egocentric distances to environmental objects. They are of crucial importance for the design of optimized rehabilitation procedures.

  18. Adaptive Gaze Strategies for Locomotion with Constricted Visual Field

    Science.gov (United States)

    Authié, Colas N.; Berthoz, Alain; Sahel, José-Alain; Safran, Avinoam B.

    2017-01-01

    In retinitis pigmentosa (RP), loss of peripheral visual field accounts for most difficulties encountered in visuo-motor coordination during locomotion. The purpose of this study was to accurately assess the impact of peripheral visual field loss on gaze strategies during locomotion, and identify compensatory mechanisms. Nine RP subjects presenting a central visual field limited to 10–25° in diameter, and nine healthy subjects were asked to walk in one of three directions—straight ahead to a visual target, leftward and rightward through a door frame, with or without obstacle on the way. Whole body kinematics were recorded by motion capture, and gaze direction in space was reconstructed using an eye-tracker. Changes in gaze strategies were identified in RP subjects, including extensive exploration prior to walking, frequent fixations of the ground (even knowing no obstacle was present), of door edges, essentially of the proximal one, of obstacle edge/corner, and alternating door edges fixations when approaching the door. This was associated with more frequent, sometimes larger rapid-eye-movements, larger movements, and forward tilting of the head. Despite the visual handicap, the trajectory geometry was identical between groups, with a small decrease in walking speed in RPs. These findings identify the adaptive changes in sensory-motor coordination, in order to ensure visual awareness of the surrounding, detect changes in spatial configuration, collect information for self-motion, update the postural reference frame, and update egocentric distances to environmental objects. They are of crucial importance for the design of optimized rehabilitation procedures. PMID:28798674

  19. Subjective method of refractometry and depth of focus

    OpenAIRE

    Sergienko, Nikolai M.; Gromova, Anastasia; Sergienko, Nikolai

    2012-01-01

    Purpose: To study the impact of the depth of focus on subjective refraction and distribution of myopic and hyperopic refractions. Methods: A total of 450 eyes of 305 subjects in the age range of 23–34 years were recruited for the study. A distribution of refractions was examined using a traditional method of the subjective refractometry on the basis of point-like posterior focus notion. Correction of the results was made on the assumption that the emmetropic eye retains high visual acuity ...

  20. WebVis: a hierarchical web homepage visualizer

    Science.gov (United States)

    Renteria, Jose C.; Lodha, Suresh K.

    2000-02-01

    WebVis, the Hierarchical Web Home Page Visualizer, is a tool for managing home web pages. The user can access this tool via the WWW and obtain a hierarchical visualization of one's home web pages. WebVis is a real time interactive tool that supports many different queries on the statistics of internal files such as sizes, age, and type. In addition, statistics on embedded information such as VRML files, Java applets, images and sound files can be extracted and queried. Results of these queries are visualized using color, shape and size of different nodes of the hierarchy. The visualization assists the user in a variety of task, such as quickly finding outdated information or locate large files. WebVIs is one solution to the growing web space maintenance problem. Implementation of WebVis is realized with Perl and Java. Perl pattern matching and file handling routines are used to collect and process web space linkage information and web document information. Java utilizes the collected information to produce visualization of the web space. Java also provides WebVis with real time interactivity, while running off the WWW. Some WebVis examples of home web page visualization are presented.

  1. Comparison of congruence judgment and auditory localization tasks for assessing the spatial limits of visual capture.

    Science.gov (United States)

    Bosen, Adam K; Fleming, Justin T; Brown, Sarah E; Allen, Paul D; O'Neill, William E; Paige, Gary D

    2016-12-01

    Vision typically has better spatial accuracy and precision than audition and as a result often captures auditory spatial perception when visual and auditory cues are presented together. One determinant of visual capture is the amount of spatial disparity between auditory and visual cues: when disparity is small, visual capture is likely to occur, and when disparity is large, visual capture is unlikely. Previous experiments have used two methods to probe how visual capture varies with spatial disparity. First, congruence judgment assesses perceived unity between cues by having subjects report whether or not auditory and visual targets came from the same location. Second, auditory localization assesses the graded influence of vision on auditory spatial perception by having subjects point to the remembered location of an auditory target presented with a visual target. Previous research has shown that when both tasks are performed concurrently they produce similar measures of visual capture, but this may not hold when tasks are performed independently. Here, subjects alternated between tasks independently across three sessions. A Bayesian inference model of visual capture was used to estimate perceptual parameters for each session, which were compared across tasks. Results demonstrated that the range of audiovisual disparities over which visual capture was likely to occur was narrower in auditory localization than in congruence judgment, which the model indicates was caused by subjects adjusting their prior expectation that targets originated from the same location in a task-dependent manner.

  2. Development of Object Permanence in Visually Impaired Infants.

    Science.gov (United States)

    Rogers, S. J.; Puchalski, C. B.

    1988-01-01

    Development of object permanence skills was examined longitudinally in 20 visually impaired infants (ages 4-25 months). Order of skill acquisition and span of time required to master skills paralleled that of sighted infants, but the visually impaired subjects were 8-12 months older than sighted counterparts when similar skills were acquired.…

  3. Improved automated perimetry performance in elderly subjects after listening to Mozart

    Directory of Open Access Journals (Sweden)

    Junia Cabral Marques

    2009-01-01

    Full Text Available PURPOSE: To evaluate the performance of automated perimetry of elderly subjects naïve to AP after listening to a Mozart sonata. INTRODUCTION: Automated perimetry (AP is a psychophysical test used to assess visual fields in patients with neurological disorders and glaucoma. In a previous study, Fiorelli et al. showed that young subjects who listened to a Mozart sonata prior to undergoing AP performed better in terms of reliability than those who did not listen to the sonata. METHODS: Fifty-two AP-naïve, normal subjects underwent Automated perimetry (SITA 24-2. The study group (25 subjects underwent AP after listening to Mozart's Sonata for Two Pianos in D Major, and the control group (27 subjects underwent Automated perimetry without prior exposure to the music. RESULTS: The study group had significantly lower false negative rates and a lower visual field reliability score than the controls (P=0.04 and P=0.04, respectively. The test time was shorter for the study group (P=0.03. DISCUSSION: This study shows that elderly subjects, when exposed to the Mozart sonata immediately before AP testing, have lower false negative rates and lower visual field reliability scores when compared with an age- and gender-matched control group. Our results differ from those of Fiorelli et al. who found lower false positive rates and less fixation loss in addition to lower false negative rates. CONCLUSION: Listening to a Mozart sonata seems to improve automated perimetry reliability in elderly subjects.

  4. [Are Visual Field Defects Reversible? - Visual Rehabilitation with Brains].

    Science.gov (United States)

    Sabel, B A

    2017-02-01

    Visual field defects are considered irreversible because the retina and optic nerve do not regenerate. Nevertheless, there is some potential for recovery of the visual fields. This can be accomplished by the brain, which analyses and interprets visual information and is able to amplify residual signals through neuroplasticity. Neuroplasticity refers to the ability of the brain to change its own functional architecture by modulating synaptic efficacy. This is actually the neurobiological basis of normal learning. Plasticity is maintained throughout life and can be induced by repetitively stimulating (training) brain circuits. The question now arises as to how plasticity can be utilised to activate residual vision for the treatment of visual field loss. Just as in neurorehabilitation, visual field defects can be modulated by post-lesion plasticity to improve vision in glaucoma, diabetic retinopathy or optic neuropathy. Because almost all patients have some residual vision, the goal is to strengthen residual capacities by enhancing synaptic efficacy. New treatment paradigms have been tested in clinical studies, including vision restoration training and non-invasive alternating current stimulation. While vision training is a behavioural task to selectively stimulate "relative defects" with daily vision exercises for the duration of 6 months, treatment with alternating current stimulation (30 min. daily for 10 days) activates and synchronises the entire retina and brain. Though full restoration of vision is not possible, such treatments improve vision, both subjectively and objectively. This includes visual field enlargements, improved acuity and reaction time, improved orientation and vision related quality of life. About 70 % of the patients respond to the therapies and there are no serious adverse events. Physiological studies of the effect of alternating current stimulation using EEG and fMRI reveal massive local and global changes in the brain. These include

  5. Generation of oculomotor images during tasks requiring visual recognition of polygons.

    Science.gov (United States)

    Olivier, G; de Mendoza, J L

    2001-06-01

    This paper concerns the contribution of mentally simulated ocular exploration to generation of a visual mental image. In Exp. 1, repeated exploration of the outlines of an irregular decagon allowed an incidental learning of the shape. Analyses showed subjects memorized their ocular movements rather than the polygon. In Exp. 2, exploration of a reversible figure such as a Necker cube varied in opposite directions. Then, both perspective possibilities are presented. The perspective the subjects recognized depended on the way they explored the ambiguous figure. In both experiments, during recognition the subjects recalled a visual mental image of the polygon they compared with the different polygons proposed for recognition. To interpret the data, hypotheses concerning common processes underlying both motor intention of ocular movements and generation of a visual image are suggested.

  6. Health Care Access Among Deaf People.

    Science.gov (United States)

    Kuenburg, Alexa; Fellinger, Paul; Fellinger, Johannes

    2016-01-01

    Access to health care without barriers is a clearly defined right of people with disabilities as stated by the UN Convention on the Rights of People with Disabilities. The present study reviews literature from 2000 to 2015 on access to health care for deaf people and reveals significant challenges in communication with health providers and gaps in global health knowledge for deaf people including those with even higher risk of marginalization. Examples of approaches to improve access to health care, such as providing powerful and visually accessible communication through the use of sign language, the implementation of important communication technologies, and cultural awareness trainings for health professionals are discussed. Programs that raise health knowledge in Deaf communities and models of primary health care centers for deaf people are also presented. Published documents can empower deaf people to realize their right to enjoy the highest attainable standard of health. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. The interblink interval in normal and dry eye subjects

    Directory of Open Access Journals (Sweden)

    Johnston PR

    2013-02-01

    Full Text Available Patrick R Johnston,1 John Rodriguez,1 Keith J Lane,1 George Ousler,1 Mark B Abelson1,21Ora, Inc, Andover, MA, USA; 2Schepens Eye Research Institute and Harvard Medical School, Boston, MA, USAPurpose: Our aim was to extend the concept of blink patterns from average interblink interval (IBI to other aspects of the distribution of IBI. We hypothesized that this more comprehensive approach would better discriminate between normal and dry eye subjects.Methods: Blinks were captured over 10 minutes for ten normal and ten dry eye subjects while viewing a standardized televised documentary. Fifty-five blinks were analyzed for each of the 20 subjects. Means, standard deviations, and autocorrelation coefficients were calculated utilizing a single random effects model fit to all data points and a diagnostic model was subsequently fit to predict probability of a subject having dry eye based on these parameters.Results: Mean IBI was 5.97 seconds for normal versus 2.56 seconds for dry eye subjects (ratio: 2.33, P = 0.004. IBI variability was 1.56 times higher in normal subjects (P < 0.001, and the autocorrelation was 1.79 times higher in normal subjects (P = 0.044. With regard to the diagnostic power of these measures, mean IBI was the best dry eye versus normal classifier using receiver operating characteristics (0.85 area under curve (AUC, followed by the standard deviation (0.75 AUC, and lastly, the autocorrelation (0.63 AUC. All three predictors combined had an AUC of 0.89. Based on this analysis, cutoffs of ≤3.05 seconds for median IBI, and ≤0.73 for the coefficient of variation were chosen to classify dry eye subjects.Conclusion: (1 IBI was significantly shorter for dry eye patients performing a visual task compared to normals; (2 there was a greater variability of interblink intervals in normal subjects; and (3 these parameters were useful as diagnostic predictors of dry eye disease. The results of this pilot study merit investigation of IBI

  8. Balance Functional Assessment in People with Visual Impairment

    Directory of Open Access Journals (Sweden)

    Rutkowska Izabela

    2015-12-01

    Full Text Available The aims of this study were twofold: to assess the level of balance of people with visual impairment against the BOT-2 standard scores for the able-bodied, and to identify in which trials subjects had the greatest difficulties in maintaining balance with respect to the degree of vision loss and age categories. One hundred twenty-seven subjects with visual impairment aged 6-16 years, participated in the study (68 girls and 59 boys. The division for partially sighted people (61 and the blind (66 was made according to the WHO classification. Functional balance assessment was made using a balance subtest from the Bruininks-Oseretsky test. Significant relationships were noticed between age and the level of balance (χ2 = 8.35 p <0,05, as well as between the degree of vision loss and the level of balance (χ2 = 24.53 p <0,001. The level of balance of almost all blind subjects was below (20% or well-below (60% the average for the able-bodied. The subjects’ ability to maintain balance was not dependent on gender and was associated primarily with the degree of visual impairment and age. Partially sighted people had better balance than the blind and the decrease in visual acuity resulted in reduction of balance skills. The lowest level of balance was observed in blind students aged 7-11 years. Elaborating physical fitness improvement programs for children and adolescents with visual impairment, diversity of age, the degree of vision loss and limitations of ablility to maintain balance should be taken into account.

  9. Visual fatigue modeling for stereoscopic video shot based on camera motion

    Science.gov (United States)

    Shi, Guozhong; Sang, Xinzhu; Yu, Xunbo; Liu, Yangdong; Liu, Jing

    2014-11-01

    As three-dimensional television (3-DTV) and 3-D movie become popular, the discomfort of visual feeling limits further applications of 3D display technology. The cause of visual discomfort from stereoscopic video conflicts between accommodation and convergence, excessive binocular parallax, fast motion of objects and so on. Here, a novel method for evaluating visual fatigue is demonstrated. Influence factors including spatial structure, motion scale and comfortable zone are analyzed. According to the human visual system (HVS), people only need to converge their eyes to the specific objects for static cameras and background. Relative motion should be considered for different camera conditions determining different factor coefficients and weights. Compared with the traditional visual fatigue prediction model, a novel visual fatigue predicting model is presented. Visual fatigue degree is predicted using multiple linear regression method combining with the subjective evaluation. Consequently, each factor can reflect the characteristics of the scene, and the total visual fatigue score can be indicated according to the proposed algorithm. Compared with conventional algorithms which ignored the status of the camera, our approach exhibits reliable performance in terms of correlation with subjective test results.

  10. Distance Education for People with Visual Impairments

    Science.gov (United States)

    Liakou, Maria; Manousou, Evaggelia

    2015-01-01

    This paper studies the standards of higher Distance Education, focusing on the Hellenic Open University, for people who have visual impairments, so that it becomes fully accessible and thus helps reduce social exclusion. Specifically, it aims to study the operational context of Distance Education, the possibilities that modern technology provides…

  11. Temporal integration windows for naturalistic visual sequences.

    Directory of Open Access Journals (Sweden)

    Scott L Fairhall

    Full Text Available There is increasing evidence that the brain possesses mechanisms to integrate incoming sensory information as it unfolds over time-periods of 2-3 seconds. The ubiquity of this mechanism across modalities, tasks, perception and production has led to the proposal that it may underlie our experience of the subjective present. A critical test of this claim is that this phenomenon should be apparent in naturalistic visual experiences. We tested this using movie-clips as a surrogate for our day-to-day experience, temporally scrambling them to require (re- integration within and beyond the hypothesized 2-3 second interval. Two independent experiments demonstrate a step-wise increase in the difficulty to follow stimuli at the hypothesized 2-3 second scrambling condition. Moreover, only this difference could not be accounted for by low-level visual properties. This provides the first evidence that this 2-3 second integration window extends to complex, naturalistic visual sequences more consistent with our experience of the subjective present.

  12. Increasing Access and Relevance in Distance Education

    Science.gov (United States)

    Mendenhall, Robert W.

    2009-01-01

    Access to higher education is subject to many factors including affordability, time and geography. Distance education can deliver education to those that live far from a campus. Some of that distance education may be synchronous, or live, requiring students to be available at certain times. Flexibility and access are increased when the instruction…

  13. Will musculoskeletal and visual stress change when Visual Display Unit (VDU) operators move from small offices to an ergonomically optimized office landscape?

    Science.gov (United States)

    Helland, Magne; Horgen, Gunnar; Kvikstad, Tor Martin; Garthus, Tore; Aarås, Arne

    2011-11-01

    This study investigated the effect of moving from small offices to a landscape environment for 19 Visual Display Unit (VDU) operators at Alcatel Denmark AS. The operators reported significantly improved lighting condition and glare situation. Further, visual discomfort was also significantly reduced on a Visual Analogue Scale (VAS). There was no significant correlation between lighting condition and visual discomfort neither in the small offices nor in the office landscape. However, visual discomfort correlated significantly with glare in small offices i.e. more glare is related to more visual discomfort. This correlation disappeared after the lighting system in the office landscape had been improved. There was also a significant correlation between glare and itching of the eyes as well as blurred vision in the small offices, i.e. more glare more visual symptoms. Experience of pain was found to reduce the subjective assessment of work capacity during VDU tasks. There was a significant correlation between visual discomfort and reduced work capacity in small offices and in the office landscape. When moving from the small offices to the office landscape, there was a significant reduction in headache as well as back pain. No significant changes in pain intensity in the neck, shoulder, forearm, and wrist/hand were observed. The pain levels in different body areas were significantly correlated with subjective assessment of reduced work capacity in small offices and in the office landscape. By careful design and construction of an office landscape with regard to lighting and visual conditions, transfer from small offices may be acceptable from a visual-ergonomic point of view. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  14. Flow visualization through metal enclosures with neutron radiography

    International Nuclear Information System (INIS)

    Cimbala, J.M.; Sathianathan, D.; Cosgrove, S.A.

    1989-01-01

    Many practical fluid flow problems involve flow inside metal shrouds (valves, combustors, boilers, turbomachinery, etc.) where visual access is not available. For flows under extreme pressure or heat, glass or transparent plastic can not be used; a flow visualization technique which permits visualization through metal containers is needed in these cases. Since neutrons can penetrate metal casings, neutron radiography has been developed for application to fluid flow visualization. This technique involves imaging of neutron opaque tracer materials, such as solid or fluid particles or streaklines, as they convect in neutron transparent ambient fluids. Surface flow visualization is also possible by using neutron opaque tufts. An extension of the surface tuft technique has also been developed, enabling the visualization of flow a patterns away from solid surfaces. This paper presents a summary of the various flow visualization techniques developed in the authors' laboratory, along with examples which illustrate how these techniques may be applied to practical fluid flow problems. These include flow over a circular cylinder, the recirculation pattern formed by a jet exhausting into a tank, and the flow pattern inside a rotating automotive torque converter

  15. A Theorem on Grid Access Control

    Institute of Scientific and Technical Information of China (English)

    XU ZhiWei(徐志伟); BU GuanYing(卜冠英)

    2003-01-01

    The current grid security research is mainly focused on the authentication of grid systems. A problem to be solved by grid systems is to ensure consistent access control. This problem is complicated because the hosts in a grid computing environment usually span multiple autonomous administrative domains. This paper presents a grid access control model, based on asynchronous automata theory and the classic Bell-LaPadula model. This model is useful to formally study the confidentiality and integrity problems in a grid computing environment. A theorem is proved, which gives the necessary and sufficient conditions to a grid to maintain confidentiality.These conditions are the formalized descriptions of local (node) relations or relationship between grid subjects and node subjects.

  16. NASA's Global Imagery Browse Services - Technologies for Visualizing Earth Science Data

    Science.gov (United States)

    Cechini, M. F.; Boller, R. A.; Baynes, K.; Schmaltz, J. E.; Thompson, C. K.; Roberts, J. T.; Rodriguez, J.; Wong, M. M.; King, B. A.; King, J.; De Luca, A. P.; Pressley, N. N.

    2017-12-01

    For more than 20 years, the NASA Earth Observing System (EOS) has collected earth science data for thousands of scientific parameters now totaling nearly 15 Petabytes of data. In 2013, NASA's Global Imagery Browse Services (GIBS) formed its vision to "transform how end users interact and discover [EOS] data through visualizations." This vision included leveraging scientific and community best practices and standards to provide a scalable, compliant, and authoritative source for EOS earth science data visualizations. Since that time, GIBS has grown quickly and now services millions of daily requests for over 500 imagery layers representing hundreds of earth science parameters to a broad community of users. For many of these parameters, visualizations are available within hours of acquisition from the satellite. For others, visualizations are available for the entire mission of the satellite. The GIBS system is built upon the OnEarth and MRF open source software projects, which are provided by the GIBS team. This software facilitates standards-based access for compliance with existing GIS tools. The GIBS imagery layers are predominantly rasterized images represented in two-dimensional coordinate systems, though multiple projections are supported. The OnEarth software also supports the GIBS ingest pipeline to facilitate low latency updates to new or updated visualizations. This presentation will focus on the following topics: Overview of GIBS visualizations and user community Current benefits and limitations of the OnEarth and MRF software projects and related standards GIBS access methods and their in/compatibilities with existing GIS libraries and applications Considerations for visualization accuracy and understandability Future plans for more advanced visualization concepts including Vertical Profiles and Vector-Based Representations Future plans for Amazon Web Service support and deployments

  17. Merging Psychophysical and Psychometric Theory to Estimate Global Visual State Measures from Forced-Choices

    International Nuclear Information System (INIS)

    Massof, Robert W; Schmidt, Karen M; Laby, Daniel M; Kirschen, David; Meadows, David

    2013-01-01

    Visual acuity, a forced-choice psychophysical measure of visual spatial resolution, is the sine qua non of clinical visual impairment testing in ophthalmology and optometry patients with visual system disorders ranging from refractive error to retinal, optic nerve, or central visual system pathology. Visual acuity measures are standardized against a norm, but it is well known that visual acuity depends on a variety of stimulus parameters, including contrast and exposure duration. This paper asks if it is possible to estimate a single global visual state measure from visual acuity measures as a function of stimulus parameters that can represent the patient's overall visual health state with a single variable. Psychophysical theory (at the sensory level) and psychometric theory (at the decision level) are merged to identify the conditions that must be satisfied to derive a global visual state measure from parameterised visual acuity measures. A global visual state measurement model is developed and tested with forced-choice visual acuity measures from 116 subjects with no visual impairments and 560 subjects with uncorrected refractive error. The results are in agreement with the expectations of the model

  18. Macular pigment and visual performance in glare: benefits for photostress recovery, disability glare, and visual discomfort.

    Science.gov (United States)

    Stringham, James M; Garcia, Paul V; Smith, Peter A; McLin, Leon N; Foutch, Brian K

    2011-09-22

    One theory of macular pigment's (MP) presence in the fovea is to improve visual performance in glare. This study sought to determine the effect of MP level on three aspects of visual performance in glare: photostress recovery, disability glare, and visual discomfort. Twenty-six subjects participated in the study. Spatial profiles of MP optical density were assessed with heterochromatic flicker photometry. Glare was delivered via high-bright-white LEDs. For the disability glare and photostress recovery portions of the experiment, the visual task consisted of correct identification of a 1° Gabor patch's orientation. Visual discomfort during the glare presentation was assessed with a visual discomfort rating scale. Pupil diameter was monitored with an infrared (IR) camera. MP level correlated significantly with all the outcome measures. Higher MP optical densities (MPODs) resulted in faster photostress recovery times (average P disability glare contrast thresholds (average P visual discomfort (P = 0.002). Smaller pupil diameter during glare presentation significantly correlated with higher visual discomfort ratings (P = 0.037). MP correlates with three aspects of visual performance in glare. Unlike previous studies of MP and glare, the present study used free-viewing conditions, in which effects of iris pigmentation and pupil size could be accounted for. The effects described, therefore, can be extended more confidently to real-world, practical visual performance benefits. Greater iris constriction resulted (paradoxically) in greater visual discomfort. This finding may be attributable to the neurobiologic mechanism that mediates the pain elicited by light.

  19. Visual Search for Feature and Conjunction Targets with an Attention Deficit

    OpenAIRE

    Arguin, Martin; Joanette, Yves; Cavanagh, Patrick

    1993-01-01

    Brain-damaged subjects who had previously been identified as suffering from a visual attention deficit for contralesional stimulation were tested on a series of visual search tasks. The experiments examined the hypothesis that the processing of single features is preattentive but that feature integration, necessary for the correct perception of conjunctions of features, requires attention (Treisman & Gelade, 1980 Treisman & Sato, 1990). Subjects searched for a feature target (orientation or c...

  20. Electropysiologic evaluation of the visual pathway in patients with multiple sclerosis.

    Science.gov (United States)

    Rodriguez-Mena, Diego; Almarcegui, Carmen; Dolz, Isabel; Herrero, Raquel; Bambo, Maria P; Fernandez, Javier; Pablo, Luis E; Garcia-Martin, Elena

    2013-08-01

    To evaluate the ability of visual evoked potentials and pattern electroretinograms (PERG) to detect subclinical axonal damage in patients during the early diagnostic stage of multiple sclerosis (MS). The authors also compared the ability of optical coherence tomography (OCT), PERG, and visual evoked potentials to detect axonal loss in MS patients and correlated the functional and structural properties of the retinal nerve fiber layer. Two hundred twenty-eight eyes of 114 subjects (57 MS patients and 57 age- and sex-matched healthy controls) were included. The visual pathway was evaluated based on functional and structural assessments. All patients underwent a complete ophthalmic examination that included assessment of visual acuity, ocular motility, intraocular pressure, visual field, papillary morphology, OCT, visual evoked potentials, and PERG. Visual evoked potentials (P100 latency and amplitude), PERG (N95 amplitude and N95/P50 ratio), and OCT parameters differed significantly between MS patients and healthy subjects. Moderate significant correlations were found between visual evoked potentials or PERG parameters and OCT measurements. Axonal damage in ganglion cells of the visual pathway can be detected based on structural measures provided by OCT in MS patients and by the N95 component and N95/P50 index of PERG, thus providing good correlation between function and structure.