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Sample records for 25-item visual function

  1. Psychometric properties of the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25, Japanese version

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    Oki Kotaro

    2005-10-01

    Full Text Available Abstract Background The importance of evaluating the outcomes of health care from the standpoint of the patient is now widely recognized. The purpose of this study is to develop and test a Japanese version of the National Eye Institute Visual Function Questionnaire (NEI VFQ-25. Methods A Japanese version was developed with a previously standardized method. The questionnaire and optional items were completed by 245 patients with cataracts, glaucoma, or age-related macular degeneration, by 110 others before and after cataract surgery, and by a reference group (n = 31. We computed rates of missing data, measured reproducibility and internal consistency reliability, and tested for convergent and discriminant validity, concurrent validity, known-groups validity, factor structure, and responsiveness to change. Results Based on information from the participants, some items were changed to 2-step items (asking if an activity was done, and if it was done, then asking how difficult it was. The near-vision and distance-vision subscales each had 1 item that was endorsed by very few participants, so these items were replaced with items that were optional in the English version. For example, more than 60% of participants did not drive, so the driving question was excluded. Reliability and validity were adequate for all subscales except driving, ocular pain, color vision, and peripheral vision. With cataract surgery, most scores improved by at least 20 points. Conclusion With minor modifications from the English version, the Japanese NEI VFQ-25 can give reliable, valid, responsive data on vision-related quality of life, for group-level comparisons or for tracking therapeutic outcomes.

  2. The Functions of Visual Management

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    Tezel, Algan; Koskela, Lauri; Tzortzopoulos, Patricia

    2009-01-01

    Visual Management has been evolving and effectively employed in some manufacturing and service organisations for a long time. In order to facilitate a cross-industrial learning process and to advance in detailed research the understanding of how the Visual Management concept may serve in an organisation is necessary. The aim of this paper is to identify Visual Management functions and the theoretical base for the construction industry. A detailed literature review and an analysis of the findi...

  3. Data Visualization using Spline Functions

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    Maria Hussain

    2013-10-01

    Full Text Available A two parameter family of C1  rational cubic spline functions is presented for the graphical representation of shape preserving curve interpolation for shaped data. These parameters have a direct impact on the shape of the curve. Constraints are developed on one family of the parameters to visualize positive, monotone and convex data while other family of parameters can assume any positive values. The problem of visualization of constrained data is also addressed when the data is lying above a straight line and curve is required to lie on the same side of the line. The approximation order of the proposed rational cubic function is also investigated and is found to be O(h3  .

  4. Visual function of the idiopathic macular hole

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    Jian-Tao Ren

    2015-02-01

    Full Text Available The idiopathic macular hole(IMHis research priority associated with the regenerate quickly of vitrectomy. The unaided visual acuity and the best corrected visual acuity is partial for the visual acuity of the patient with IMH.The mechanism and clinical significance of modern visual function measurements associated with IMH, including contrast sensitivity, visual field, multifocal electroretinogram, and stereoscopic vision, have been introduced. These measurements could be of great value in early diagnosis of IMH, assessment of surgical indication and evaluation of visual performance after vitrectomy. They would also be helpful to the analysis of postoperative impaired visual function and its management. Having an adequate understanding of the contents and significance of visual function is helpful to the improvement of IMH surgery techniques and postoperative visual acuity.

  5. [Determination of visual function in legal assessment].

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    Springer, C; Bültmann, S; Krastel, H; Rohrschneider, K

    2007-06-01

    For the determination of visual function an objective assessment is essential. Basic ophthalmologic examinations such as measurement of visual acuity and perimetry are dependent on patient statements. If the patient is not being able to provide adequate answers, as is the case for small children or mentally retarded patients, or also if the accuracy of the patient's statements is doubtful or simulation or aggravation is suspected, the denoted function in the evaluation of visual acuity has to be checked on consistency using different examination methods, and the results of objective functional tests, such as electrophysiology and morphological features, have to be taken into account.

  6. Visual-field function in pseudophakia.

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    Klewin, K M; Radius, R L; Schultz, R O

    1988-08-01

    An automated perimeter (Octopus 2000) was used to examine visual-field function in 52 pseudophakic eyes. Threshold sensitivity was reduced throughout the visual field by from 0.4 to 20.0 decibels from that of threshold sensitivity in age-matched normal eyes. This reduction was comparable to that seen in contact-lens-corrected aphakic eyes.

  7. Armstrong Laboratory Space Visual Function Tester Program

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    Oneal, Melvin R.; Task, H. Lee; Gleason, Gerald A.

    1992-01-01

    Viewgraphs on space visual function tester program are presented. Many astronauts and cosmonauts have commented on apparent changes in their vision while on-orbit. Comments have included descriptions of earth features and objects that would suggest enhanced distance visual acuity. In contrast, some cosmonaut observations suggest a slight loss in their object discrimination during initial space flight. Astronauts have also mentioned a decreased near vision capability that did not recover to normal until return to earth. Duntley space vision experiment, USSR space vision experiments, and visual function testers are described.

  8. Visual Servoing via Navigation Functions

    Science.gov (United States)

    2002-02-06

    notation, we write ϕ ◦ ψ(q) = ϕ(q), and hence, in local coordinates ∇ϕ(q) = M−1(q) DTq ϕ(q) where (Dqϕ)i = ∂ϕ ∂qi , and M is the local representation of...the Riemannian metric. Gradient descent can now be achieved in local coordinates via q̇ = −M−1(q) DTq ϕ(q) (12) A smooth scalar valued function whose

  9. Visual function with acupuncture tested by visual evoked potential.

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    Sagara, Yoshiko; Fuse, Nobuo; Seimiya, Motohiko; Yokokura, Syunji; Watanabe, Kei; Nakazawa, Toru; Kurusu, Masayuki; Seki, Takashi; Tamai, Makoto

    2006-07-01

    Visual evoked potential (VEP) testing is used frequently and is an important ophthalmologic physiological test to examine visual functions objectively. The VEP is a complicated waveform consisting of negative waveform named N75 and N135, and positive waveform named P100. Delayed P100 latency and greatly attenuated amplitude on VEP are known characteristics for diagnosing optic nerve disease. Acupuncture has been used to treat wide clinical symptoms with minimal side effects. The confirmation of the efficacy of acupuncture generally relies on subjective symptoms. There is not much scientific evidence supporting the acupuncture treatments for eye diseases up to today. However, the VEP test can evaluate objectively and numerically the efficacy of the treatment by the acupuncture. We analyzed 19 healthy subjects (38 eyes). The P100 latencies in the group of less than 101.7 msec (total average) before acupuncture stimulations were not different than those after treatment (98.2 +/- 3.0 msec, 98.2 +/- 4.0 msec, respectively, p = 0.88, n = 17), but the latencies in those subjects with longer or equal to 101.7 msec were statistically different after acupuncture (104.6 +/- 2.8 msec, 101.9 +/- 3.7 msec, respectively, p = 0.006, n = 21). These results show that the acupuncture stimulation contributes to the P100 latencies of pattern reversal (PR)-VEP to some subjects who have delayed latencies, and this electrophysiological method is a valuable technique in monitoring the effectiveness of acupuncture therapy in the improvements of visual functions. The purpose of this study is to evaluate the physiological effects by acupuncture stimulations using PR-VEP in normal subjects.

  10. Which visual functions depend on intermediate visual regions? Insights from a case of developmental visual form agnosia.

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    Gilaie-Dotan, Sharon

    2016-03-01

    A key question in visual neuroscience is the causal link between specific brain areas and perceptual functions; which regions are necessary for which visual functions? While the contribution of primary visual cortex and high-level visual regions to visual perception has been extensively investigated, the contribution of intermediate visual areas (e.g. V2/V3) to visual processes remains unclear. Here I review more than 20 visual functions (early, mid, and high-level) of LG, a developmental visual agnosic and prosopagnosic young adult, whose intermediate visual regions function in a significantly abnormal fashion as revealed through extensive fMRI and ERP investigations. While expectedly, some of LG's visual functions are significantly impaired, some of his visual functions are surprisingly normal (e.g. stereopsis, color, reading, biological motion). During the period of eight-year testing described here, LG trained on a perceptual learning paradigm that was successful in improving some but not all of his visual functions. Following LG's visual performance and taking into account additional findings in the field, I propose a framework for how different visual areas contribute to different visual functions, with an emphasis on intermediate visual regions. Thus, although rewiring and plasticity in the brain can occur during development to overcome and compensate for hindering developmental factors, LG's case seems to indicate that some visual functions are much less dependent on strict hierarchical flow than others, and can develop normally in spite of abnormal mid-level visual areas, thereby probably less dependent on intermediate visual regions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Functional magnetic resonance imaging evaluation of visual cortex activation in patients with anterior visual pathway lesions

    Institute of Scientific and Technical Information of China (English)

    Xiufeng Song; Guohua Wang; Tong Zhang; Lei Feng; Peng An; Yueli Zhu

    2012-01-01

    The aim of this study was to examine the secondary visual cortex functional disorder in patients with glaucoma and large pituitary adenoma by functional magnetic resonance imaging, and to determine the correlation between visual field defect and primary visual cortex activation. Results showed that single eye stimulation resulted in bilateral visual cortex activation in patients with glaucoma or large pituitary adenoma. Compared with the normal control group, the extent and intensity of visual cortex activation was decreased after left and right eye stimulation, and functional magnetic resonance imaging revealed a correlation between visual field defects and visual cortex activation in patients with glaucoma and large pituitary adenoma. These functional magnetic resonance imaging data suggest that anterior optic pathway lesions can cause secondary functional disorder of the visual cortex, and that visual defects are correlated with visual cortex activation.

  12. Assessing the functions and dimensions of visualizations in foresight

    DEFF Research Database (Denmark)

    Müller, Adrian W.; Schwarz, Jan Oliver

    practice, it appears that in the realm of foresight little is known about what we call the functions and dimensions of visualization. The function of visualizations in foresight speaks from a constructive perspective to the influence visual images have on human perception. Cognitive scientist have argued...

  13. Visual function and vision-related quality of life after vitrectomy for idiopathic macular hole: a 12mo followup study

    Institute of Scientific and Technical Information of China (English)

    Hong-Tao; Duan; Song; Chen; Yue-Xin; Wang; Jia-Hui; Kong; Meng; Dong

    2015-01-01

    · AIM: To investigate the visual function and the relationship with vision-related quality of life(VRQOL)after macular hole repair surgery.· METHODS: Prospective case series. Thirty-six consecutive eyes in 36 patients who underwent pars plana vitrectomy(PPV) and internal limiting membrane(ILM) peeling were included. The 25-item National Eye Institute Visual Function Questionnaire(VFQ-25) was answered by the participants before and 3 and 12 mo after operation. Follow-up visits examinations included best-corrected visual acuity(BCVA), clinical examination,and central macular thickness(CMT) measured by optical coherence tomography(OCT).·RESULTS: Macular-hole closure was achieved in 35 of36 eyes(97.2%). At baseline and months 3 and 12, the log MAR BCVAs(mean±SD) were 1.15±0.47, 0.68±0.53(P <0.0001 versus baseline), and 0.55 ±0.49(P <0.001 versus baseline, P =0.273 versus month 3), respectively; the CMTs(μm) were 330 ±81, 244 ±62(P <0.001 versus baseline), and 225±58(P <0.001 versus baseline, P =0.222 versus month 3), respectively; the median preoperative VFQ-25 composite score of 73.50(63.92-81.13) increased postoperatively to 85.50(80.04-89.63) at 3mo(P <0.001)and 86.73(82.50-89.63) at 12mo(P <0.001) respectively.The improved BCVA was correlated with improvements in five subscales(r =-0.605 to-0.336, P <0.001 to P =0.046) at 12 mo.· CONCLUSION: PPV with ILM peeling improved anatomic outcome, visual function, and VRQOL. Theimproved BCVA was an important factor related to the improved VRQOL.

  14. Inferential Functioning in Visually Impaired Children

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    Puche-Navarro, Rebeca; Millan, Rafael

    2007-01-01

    The current study explores the inferential abilities of visually impaired children in a task presented in two formats, manipulative and verbal. The results showed that in the group of visually impaired children, just as with children with normal sight, there was a wide range of inference types. It was found that the visually impaired children…

  15. Remaining visual field and preserved subjective visual functioning prevent mental distress in patients with visual field defects

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    Carolin eGall

    2013-09-01

    Full Text Available Background: Patients with visual field defects after visual pathway lesion may experience reduced vision-related quality of life (vrQoL. It has not been clarified how vrQoL impairments contribute to vision-related mental distress.Methods: 108 subjects with visual field defects caused by optic neuropathies (age M=57.6; SD=13.7 years answered the National Eye Institute Visual-Functioning Questionnaire (NEI-VFQ for vrQoL and the SF-12 Short Form Health Survey for health-related quality of life (hrQoL. A ten item composite of NEI-VFQ visual functioning and five items of mental health symptoms due to vision problems were subjected to Rasch analysis. The test battery comprised static and High Resolution Perimetry (HRP. Regression and path analysis were used to investigate associations between QoL, mental distress and perimetry results.Results: A higher level of visual functioning was associated with monocular impairment and a larger remaining visual field compared to binocular impairment. Subjective visual functioning but not visual field parameters predicted mental health symptoms due to vision problems which was the only variable associated with the SF-12 mental component score. The SF-12 physical component score was less strongly associated with mental health symptoms due to vision problems. Here, reaction time in HRP and mean threshold in perimetry were additional significant variables. Path analysis revealed a significant path of remaining visual field via visual functioning on mental health. Conclusions: Subjective consequences of visual impairments in everyday life impact mental health rather than objective visual function loss as measured by perimetry. Since a higher extent of vrQoL was related to lower levels of mental distress, the maintenance of vrQoL could reduce and prevent mental distress due to vision problems. Patients with persisting visual field defects may benefit from neuropsychological rehabilitation and supportive therapies.

  16. The function of stereotypes in visual perception.

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    Niemeyer, Greg O

    2003-01-01

    Human vision is a product of both physiological and cultural dispositions. This cultural study investigates the role of cultural dispositions in visual perception. In particular, the study focuses on the role of stereotypes, which are involved in recognition. I propose that stereotypes are essential for basic functions of perception and human perception. However, stereotypes also introduce significant limitations on human experience. The fact that stereotypes are abstract simplifications of realities is not the limiting factor, since scientific and cultural progress continually refines stereotypes. The very principle of the stereotype appears to introduce the limitation, because the process of forming stereotypes requires both temporal and functional fragmentations of the continuum of our perception. This fragmentation can be a cause of sensory overload, a postmodern condition that generates cultural, perceptual and behavioral problems. To address this problem, I propose a cultural modification to our modality of perception. The modification shifts the emphasis of our perception from the recognition of stereotypes to the recognition of flows, processes and durations. References to the work of Henri Bergson and Martin Heidegger provide the philosophical basis for this modification and several empirical and experimental examples illustrate such modifications in practice.

  17. Visual functions and disability in diabetic retinopathy patients.

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    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.

  18. Visual functioning in nursing home residents

    NARCIS (Netherlands)

    Sinoo, Marianne; Kort, Helianthe; Duijnstee, Mia

    2012-01-01

    Older adults experience visual problems owing to biological ageing or eye disease. In the Netherlands, the prevalence of visual impairments is the highest in the subgroup of nursing home residents (41.3%). These impairments influence quality of life in terms of limiting daily activities and particip

  19. Visual function of children with visual and other disabilities in Oman: A case series

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    Gogri, Urmi; Khandekar, Rajiv; Al Harby, Salah

    2016-01-01

    Background: We assessed the visual functioning of the children with special needs in Oman between 2009 and 2012. We present the methods of assessing different visual functions, outcomes, and interventions carried out to improve their functioning. Methods: Optometrists assessed visual functions of children of “Day care centres” in Oman. Experts further assessed them and provided low vision care. Ocular movements, refractive corrections, near, distance, contrast color, motion, field of vision, and cognitive visual function test results were noted. Feedback to caregivers was given to improve visual functioning of these children. Results: We grouped 321 participants, (196 [61.1%] boys, age range of 3–18 years) into 61; Down syndrome (DS), 72 with intellectual disabilities (IDs), 67; hearing impaired and 121 with other conditions. Refractive error and lag of accommodation were 26 (42.6%) and 14 (22.6%) among children with DS. Contrast sensitivity was impaired in 8 (12.7%) among hearing impaired children. Defective distant and near vision was in 162 (70%) and 104 (42%) of our cohort. Children with ID were most difficult to assess. Children in a group of other disabilities had a higher proportion of impaired visual functioning. They were given low vision aids (telescopes [22], filters [7], and magnifiers [3]) in large numbers compared to those in other groups. Conclusions: Visual functioning of children with other disabilities show great variation and difficult to group. The care, therefore, should be at individual level. All visual functions cannot be assessed at one time. PMID:28112128

  20. Visualizing myocardial function using HARP MRI

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    Osman, N.F. [Center for Imaging Science, Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD 21218 (United States); Prince, J.L. [Center for Imaging Science, Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD 21218 (United States). E-mail: prince at jhu.edu

    2000-06-01

    Harmonic phase magnetic resonance imaging (HARP) is a new technique for measuring the motion of the left ventricle of the heart. HARP uses magnetic resonance tagging, Fourier filtering and special processing algorithms to calculate key indices of myocardial motion including Eulerian and Lagrangian strain. This paper presents several new methods for visualizing myocardial motion based on HARP. Quantities that are computed and visualized include motion grids, velocity fields, strain rates, pathlines, tracked Eulerian strain, and contraction angle. The computations are fast and fully automated and have the potential for clinical application. (author)

  1. Visualizing myocardial function using HARP MRI

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    Osman, Nael F.; Prince, Jerry L.

    2000-06-01

    Harmonic phase magnetic resonance imaging (HARP) is a new technique for measuring the motion of the left ventricle of the heart. HARP uses magnetic resonance tagging, Fourier filtering and special processing algorithms to calculate key indices of myocardial motion including Eulerian and Lagrangian strain. This paper presents several new methods for visualizing myocardial motion based on HARP. Quantities that are computed and visualized include motion grids, velocity fields, strain rates, pathlines, tracked Eulerian strain, and contraction angle. The computations are fast and fully automated and have the potential for clinical application.

  2. An insect-inspired model for visual binding II: functional analysis and visual attention.

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    Northcutt, Brandon D; Higgins, Charles M

    2017-04-01

    We have developed a neural network model capable of performing visual binding inspired by neuronal circuitry in the optic glomeruli of flies: a brain area that lies just downstream of the optic lobes where early visual processing is performed. This visual binding model is able to detect objects in dynamic image sequences and bind together their respective characteristic visual features-such as color, motion, and orientation-by taking advantage of their common temporal fluctuations. Visual binding is represented in the form of an inhibitory weight matrix which learns over time which features originate from a given visual object. In the present work, we show that information represented implicitly in this weight matrix can be used to explicitly count the number of objects present in the visual image, to enumerate their specific visual characteristics, and even to create an enhanced image in which one particular object is emphasized over others, thus implementing a simple form of visual attention. Further, we present a detailed analysis which reveals the function and theoretical limitations of the visual binding network and in this context describe a novel network learning rule which is optimized for visual binding.

  3. Reorganization of early visual cortex functional connectivity following selective peripheral and central visual loss.

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    Sabbah, Norman; Sanda, Nicolae; Authié, Colas N; Mohand-Saïd, Saddek; Sahel, José-Alain; Habas, Christophe; Amedi, Amir; Safran, Avinoam B

    2017-02-24

    Behavioral alterations emerging after central or peripheral vision loss suggest that cerebral reorganization occurs for both the afferented and deafferented early visual cortex (EVC). We explored the functional reorganization of the central and peripheral EVC following visual field defects specifically affecting central or peripheral vision. Compared to normally sighted, afferented central and peripheral EVC enhance their functional connectivity with areas involved in visual processing, whereas deafferented central and peripheral EVC increase their functional connectivity with more remote regions. The connectivity pattern of afferented EVC suggests adaptive changes that might enhance the visual processing capacity whereas the connectivity pattern of deafferented EVC may reflect the involvement of these regions in high-order mechanisms. Characterizing and understanding the plastic changes induced by these visual defects is essential for any attempt to develop efficient rehabilitation strategies.

  4. Relationship of Visual Cortex Function and Visual Acuity in Anisometropic Amblyopic Children

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    Chuanming Li, Lin Cheng, Qiongwu Yu, Bing Xie, Jian Wang

    2012-01-01

    Full Text Available Purpose: To detect the functional deficit of the visual cortex in anisometropic amblyopia children using functional magnetic resonance imaging (fMRI technique, and investigate the relationship between visual acuity and visual cortex function.Methods: Blood oxygenation level-dependent fMRI (BOLD-fMRI was performed in ten monocular anisometropic amblyopia children and ten normal controls. fMRI images were acquired in two runs with visual stimulation delivered separately through the sound and amblyopic eyes. Measurements were performed in cortical activation of striate and extrastriate areas at the occipital lobe. The relationship between cortex function and visual acuity was analyzed by Pearson partial analysis.Results: The activation areas of both the striate and extrastriate cortices in the amblyopic eyes were significantly lower than that of the sound fellow eyes. No relationship was found between the striate and extrastriate cortex activation. No relationship was found between the visual cortical activation of striate, extrastriate areas and visual acuity of anisometropic amblyopes.Conclusions: BOLD-fMRI revealed the independent striate and extrastriate cortical deficits in anisometropic amblyopes. In addition, the visual acuity lesion and the striate and extrastriate cortical deficits were not parallel, and results of fMRI examination have much potential value in the evaluation of amblyopia.

  5. Functional organization of telencephalic visual association fields in pigeons.

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    Stacho, Martin; Ströckens, Felix; Xiao, Qian; Güntürkün, Onur

    2016-04-15

    Birds show remarkable visual abilities that surpass most of our visual psychophysiological abilities. In this study, we investigated visual associative areas of the tectofugal visual system in pigeons. Similar to the condition in mammals, ascending visual pathways in birds are subdivided into parallel form/color vs. motion streams at the thalamic and primary telencephalic level. However, we know practically nothing about the functional organization of those telencephalic areas that receive input from the primary visual telencephalic fields. The current study therefore had two objectives: first, to reveal whether these visual associative areas of the tectofugal system are activated during visual discrimination tasks; second, to test whether separated form/color vs. motion pathways can be discerned among these association fields. To this end, we trained pigeons to discriminate either form/color or motion stimuli and used the immediate early gene protein ZENK to capture the activity of the visual associative areas during the task. We could indeed identify several visual associative telencephalic structures by activity pattern changes during discriminations. However, none of these areas displayed a difference between form/color vs. motion sessions. The presence of such a distinction in thalamo-telencephalic, but not in further downstream visual association areas opens the possibility that these separate streams converge very early in birds, which possibly minimizes long-range connections due to the evolutionary pressure toward miniaturized brains.

  6. Visual Magnocellular Function in Perceptual Disorders

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    David P. Crewther

    2011-05-01

    Full Text Available Developmental disorders such as autism spectrum disorders (ASD, dyslexia, schizophrenia and dyscalculia have also been reported to show abnormal visual perception. Central to the four disorders are observations of altered global/local perception, motion sensation and grouping that are suggestive of a magnocellular abnormality(s. Such psychophysical observations do not easily yield neurophysiological mechanisms that can explain the altered perception/vision. Nonlinear visual evoked potentials have allowed the separation of magnocellular (M and parvocellular (P contributions to the VEP (Klistorner et al., 1997. Using these tools we compare the patterns of abnormality in groups with visual disorders. The second order kernel responses of the VEP in autistic tendency show interference between P and M nonlinearities at high contrast (Sutherland & Crewther, 2010 resulting in a delay of completion of firing. While afferent latencies of M and P cortical activation are not different in ASD, the delay in completion may allow a revision of the ideas surrounding the “magnocellular advantage” which relate to the alterations observed in global and local perception.

  7. Visual Magnocellular Function in Perceptual Disorders

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    Crewther, David P.; Laycock, Robin; Jastrzebski, Nikki; Crewther, Daniel P.; Crewther, Sheila G.

    2011-01-01

    Developmental disorders such as autism spectrum disorders (ASD), dyslexia, schizophrenia and dyscalculia have also been reported to show abnormal visual perception. Central to the four disorders are observations of altered global/local perception, motion sensation and grouping that are suggestive of a magnocellular abnormality(s). Such psychophysical observations do not easily yield neurophysiological mechanisms that can explain the altered perception/vision. Nonlinear visual evoked potentials have allowed the separation of magnocellular (M) and parvocellular (P) contributions to the VEP (Klistorner et al., 1997). Using these tools we compare the patterns of abnormality in groups with visual disorders. The second order kernel responses of the VEP in autistic tendency show interference between P and M nonlinearities at high contrast (Sutherland & Crewther, 2010) resulting in a delay of completion of firing. While afferent latencies of M and P cortical activation are not different in ASD, the delay in completion may allow a revision of the ideas surrounding the “magnocellular advantage” which relate to the alterations observed in global and local perception.

  8. Structural and functional changes across the visual cortex of a patient with visual form agnosia.

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    Bridge, Holly; Thomas, Owen M; Minini, Loredana; Cavina-Pratesi, Cristiana; Milner, A David; Parker, Andrew J

    2013-07-31

    Loss of shape recognition in visual-form agnosia occurs without equivalent losses in the use of vision to guide actions, providing support for the hypothesis of two visual systems (for "perception" and "action"). The human individual DF received a toxic exposure to carbon monoxide some years ago, which resulted in a persisting visual-form agnosia that has been extensively characterized at the behavioral level. We conducted a detailed high-resolution MRI study of DF's cortex, combining structural and functional measurements. We present the first accurate quantification of the changes in thickness across DF's occipital cortex, finding the most substantial loss in the lateral occipital cortex (LOC). There are reduced white matter connections between LOC and other areas. Functional measures show pockets of activity that survive within structurally damaged areas. The topographic mapping of visual areas showed that ordered retinotopic maps were evident for DF in the ventral portions of visual cortical areas V1, V2, V3, and hV4. Although V1 shows evidence of topographic order in its dorsal portion, such maps could not be found in the dorsal parts of V2 and V3. We conclude that it is not possible to understand fully the deficits in object perception in visual-form agnosia without the exploitation of both structural and functional measurements. Our results also highlight for DF the cortical routes through which visual information is able to pass to support her well-documented abilities to use visual information to guide actions.

  9. Simultaneous visualization of anatomical and functional 3D data by combining volume rendering and flow visualization

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    Schafhitzel, Tobias; Rößler, Friedemann; Weiskopf, Daniel; Ertl, Thomas

    2007-03-01

    Modern medical imaging provides a variety of techniques for the acquisition of multi-modality data. A typical example is the combination of functional and anatomical data from functional Magnetic Resonance Imaging (fMRI) and anatomical MRI measurements. Usually, the data resulting from each of these two methods is transformed to 3D scalar-field representations to facilitate visualization. A common method for the visualization of anatomical/functional multi-modalities combines semi-transparent isosurfaces (SSD, surface shaded display) with other scalar visualization techniques like direct volume rendering (DVR). However, partial occlusion and visual clutter that typically result from the overlay of these traditional 3D scalar-field visualization techniques make it difficult for the user to perceive and recognize visual structures. This paper addresses these perceptual issues by a new visualization approach for anatomical/functional multi-modalities. The idea is to reduce the occlusion effects of an isosurface by replacing its surface representation by a sparser line representation. Those lines are chosen along the principal curvature directions of the isosurface and rendered by a flow visualization method called line integral convolution (LIC). Applying the LIC algorithm results in fine line structures that improve the perception of the isosurface's shape in a way that it is possible to render it with small opacity values. An interactive visualization is achieved by executing the algorithm completely on the graphics processing unit (GPU) of modern graphics hardware. Furthermore, several illumination techniques and image compositing strategies are discussed for emphasizing the isosurface structure. We demonstrate our method for the example of fMRI/MRI measurements, visualizing the spatial relationship between brain activation and brain tissue.

  10. Visual-Motor Maturity and Executive Functions in Schoolchildren

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    Ana Luisa Silva de Oliveira

    2016-08-01

    Full Text Available Abstract Visual-motor maturity and executive functions are closely related in the child development process. This study aimed to investigate the relation between visual-motor abilities and executive functions in 83 healthy children between 7 and 10 years old. The tools used were the Bender Gestalt Visual-Motor Test - Gradual Scoring System (B-GSS, Wisconsin Card Sorting Test (WCST, Raven's Progressive Matrices (RPM, and Rey-Osterrieth Complex Figure (ROCF. The correlation between the B-GSS and WCST scores was significantly negative (r = -.23, p < .033, while ROCF variables, such as Total Memory and Total Copy, had a moderate, significant correlation with total B-GSS score (r = -.55, p < .001; r = -.44, p < .001, respectively. The results empirically show the relation between executive functions and visual-motor maturity and are discussed in face of developmental neuropsychology.

  11. DVE: ground and airborne visualization functionalities

    Science.gov (United States)

    Barratt, Nick; Mise, Olegs; Franklin, Dustin; Preece, Andy; Schaffer, Larry

    2014-06-01

    This paper describes functional blocks (hardware and software functionalities) applicable to several forms of indirect vision enhancement in DVE (Degraded Vision Environment for pilotage, Driver's Vision Enhancement for ground vehicle Situational Awareness). These functionalities are the result of the increased processing power of General Purpose Graphics Processing Units (GPGPUs) and improvements in mosaic stitch processing, image fusion and analytics of both live and synthetic imagery. We deploy GPUs into low-latency embedded systems with decreased SWaP (Size, Weight and Power) and high-bandwidth interconnectivity via RDMA (Remote Direct Memory Access).

  12. Evaluation of contrast sensitivity and other visual function outcomes in neovascular age-related macular degeneration patients after treatment switch to aflibercept from ranibizumab.

    Science.gov (United States)

    Nixon, Donald R; Flinn, Nicholas Ap

    2017-01-01

    This study evaluated visual function and anatomic and vision-related quality-of-life outcomes in recalcitrant neovascular age-related macular degeneration (AMD) subjects switched to aflibercept (Eylea(®)) from ranibizumab (Lucentis(®)). In a single-center study conducted in Barrie, ON, 40 patients with persistent fluid despite previous ranibizumab treatment were switched to aflibercept with 3 consecutive monthly doses. Main outcome measure was mean change from baseline to week 12 in Pelli-Robson contrast sensitivity (CS). Secondary outcomes were mean change in best corrected visual acuity (BCVA), central retinal thickness (CRT), and National Eye Institute 25-Item Visual Function Questionnaire (NEI VFQ-25) score. A two-sided paired t-test was used in the statistical data analysis to compare the means of continuous variables. Forty-nine eyes (baseline visual acuity [VA] >6/120) were evaluated. Ranibizumab injections (mean ± standard deviation [SD] 28.2±22.1 [range 3-86]) were administered prior to treatment switch. Mean CS improved from 1.32 at baseline to 1.40 log units at week 12. VA was stable throughout. Mean CRT decreased from 354 µm at baseline to 332 µm at week 12 (-22 µm, P=0.004). Twenty-six (65%) patients experienced an overall improvement in NEI VFQ-25 score. Interestingly, a correlation was observed between improvement in log CS and CRT change (P=0.000046). Contrast sensitivity improved statistically and significantly, and CRT decreased from baseline to week 12 after a switch to aflibercept from ranibizumab. Analysis of CS as an independent outcome end point in neovascular AMD treatment switch studies may provide a more complete understanding of visual response.

  13. THE SIGNIFICANCE OF TESTING PREOPERATIVE VISUAL FUNCTION IN CATARACT USING LASER INTERFEROMETRIC VISUAL ACUITY AND ERG

    Institute of Scientific and Technical Information of China (English)

    1991-01-01

    Tests of preoperative visual function and prediction of postoperative E chart visual acuity(ECVA) using laser interferometric visual acuity(LIVA) and electroretinogram(ERG) were performed in 16 cases(19 eyes) of cataract. The results showed that the coincident rate between preoperative LIVA and postoperative ECVA was 63.2%, and there was a parallel correlation between preoperative amplitude of photopic ERG b-wave and postoperative ECVA in 79.0% of the eyes. Comparing these two methods, the test of LIVA ...

  14. A Geometric Approach to Visualization of Variability in Functional Data

    KAUST Repository

    Xie, Weiyi

    2016-12-19

    We propose a new method for the construction and visualization of boxplot-type displays for functional data. We use a recent functional data analysis framework, based on a representation of functions called square-root slope functions, to decompose observed variation in functional data into three main components: amplitude, phase, and vertical translation. We then construct separate displays for each component, using the geometry and metric of each representation space, based on a novel definition of the median, the two quartiles, and extreme observations. The outlyingness of functional data is a very complex concept. Thus, we propose to identify outliers based on any of the three main components after decomposition. We provide a variety of visualization tools for the proposed boxplot-type displays including surface plots. We evaluate the proposed method using extensive simulations and then focus our attention on three real data applications including exploratory data analysis of sea surface temperature functions, electrocardiogram functions and growth curves.

  15. Functional Connectivity Patterns of Visual Cortex Reflect its Anatomical Organization.

    Science.gov (United States)

    Genç, Erhan; Schölvinck, Marieke Louise; Bergmann, Johanna; Singer, Wolf; Kohler, Axel

    2016-09-01

    The brain is continuously active, even without external input or task demands. This so-called resting-state activity exhibits a highly specific spatio-temporal organization. However, how exactly these activity patterns map onto the anatomical and functional architecture of the brain is still unclear. We addressed this question in the human visual cortex. We determined the representation of the visual field in visual cortical areas of 44 subjects using fMRI and examined resting-state correlations between these areas along the visual hierarchy, their dorsal and ventral segments, and between subregions representing foveal versus peripheral parts of the visual field. We found that retinotopically corresponding regions, particularly those representing peripheral visual fields, exhibit strong correlations. V1 displayed strong internal correlations between its dorsal and ventral segments and the highest correlation with LGN compared with other visual areas. In contrast, V2 and V3 showed weaker correlations with LGN and stronger between-area correlations, as well as with V4 and hMT+. Interhemispheric correlations between homologous areas were especially strong. These correlation patterns were robust over time and only marginally altered under task conditions. These results indicate that resting-state fMRI activity closely reflects the anatomical organization of the visual cortex both with respect to retinotopy and hierarchy.

  16. 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.

  17. Visualization and analysis of functional cardiac MRI data

    Science.gov (United States)

    McVeigh, Elliot R.; Guttman, Michael A.; Poon, Eric; Pisupati, Chandrasekhar; Moore, Christopher C.; Zerhouni, Elias A.; Solaiyappan, Meiyappan; Heng, PhengAnn

    1994-05-01

    Rapid analysis of large multi-dimensional data sets is critical for the successful implementation of a comprehensive MR cardiac exam. We have developed a software package for the analysis and visualization of cardiac MR data. The program allows interactive visualization of time and space stacks of MRI data, automatic segmentation of myocardial borders and myocardial tagging patterns, and visualization of functional parameters such a motion, strain, and blood flow, mapped as colors in an interactive dynamic 3D volume rendering of the beating heart.

  18. Visual functional changes during acute elevation of intraocular pressure

    Institute of Scientific and Technical Information of China (English)

    Tian-De SHOU

    2006-01-01

    Glaucoma is closely related to elevation of intraocular pressure (IOP). Many studies have done on the effect of chronic elevation of IOP on the retina and optic nerve, but less attention was paid to the effect of acute elevated IOP. Here we briefly review experimental studies on functional changes of the visual system from the retina to the visual cortex under acute elevated IOP condition, which is similar to that of acute primary angle-closure glaucoma.

  19. Are flash-evoked visual potentials useful for intraoperative monitoring of visual pathway function?

    Science.gov (United States)

    Cedzich, C; Schramm, J; Fahlbusch, R

    1987-11-01

    Flash-evoked visual potentials (VEPs) recorded from the scalp were used in a series of 35 patients with tumors along the visual pathway: 3 orbital tumors, 25 perisellar tumors, 4 intraventricular tumors, and 3 occipital lesions. Preoperatively, various combinations of impaired visual fields and visual acuity were observed in over 90% of the patients. A postoperative decrease in visual function was observed in 3 cases. Of the 25 perisellar lesions, 13 were operated through a standard frontotemporal craniotomy and 12 were operated through a transnasal-transsphenoidal approach. VEPs were highly susceptible to volatile anesthetics, and there was a significant incidence of spontaneous latency increases and amplitude decreases in a large number of patients. There was an unacceptably high number of cases with significant VEP alteration occurring without concomitant visual function change. During trepanation or the transnasal approach, a reversible potential loss was observed in 11 patients, a profoundly altered wave form was seen in 8 cases, and a loss of single peaks was observed in 15 patients. During dissection of the tumor, a reversible potential loss or a potential with unidentifiable peaks was found in 25 cases; however, the VEPs recovered during closure or in the recovery room. There was no correlation between intraoperative VEP changes and the postoperative changes in visual function. In only 1 patient with an insignificant postoperative decrease in visual acuity from 0.4 to 0.3 was there a concomitant intraoperative potential loss. The major conclusion of our findings is that light-emitting diode flash-evoked VEPs demonstrate intraoperative changes that appear too early and too prominently to be caused solely by manipulation of the optic pathways.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Functional MRI of the visual cortex and visual testing in patients with previous optic neuritis

    DEFF Research Database (Denmark)

    Langkilde, Annika Reynberg; Frederiksen, J.L.; Rostrup, Egill

    2002-01-01

    The volume of cortical activation as detected by functional magnetic resonance imaging (fMRI) in the visual cortex has previously been shown to be reduced following optic neuritis (ON). In order to understand the cause of this change, we studied the cortical activation, both the size...... a reduced blood oxygenation level dependent (BOLD) signal increase and a greater asymmetry in the visual cortex, compared with controls. The volume of visual cortical activation was significantly correlated to the result of the contrast sensitivity test. The BOLD signal increase correlated significantly...... of the activated area and the signal change following ON, and compared the results with results of neuroophthalmological testing. We studied nine patients with previous acute ON and 10 healthy persons served as controls using fMRI with visual stimulation. In addition to a reduced activated volume, patients showed...

  1. Functional MRI of the visual cortex and visual testing in patients with previous optic neuritis

    DEFF Research Database (Denmark)

    Langkilde, Annika Reynberg; Frederiksen, J.L.; Rostrup, Egill

    2002-01-01

    to both the results of the contrast sensitivity test and to the Snellen visual acuity. Our results indicate that fMRI is a useful method for the study of ON, even in cases where the visual acuity is severely impaired. The reduction in activated volume could be explained as a reduced neuronal input......The volume of cortical activation as detected by functional magnetic resonance imaging (fMRI) in the visual cortex has previously been shown to be reduced following optic neuritis (ON). In order to understand the cause of this change, we studied the cortical activation, both the size...... of the activated area and the signal change following ON, and compared the results with results of neuroophthalmological testing. We studied nine patients with previous acute ON and 10 healthy persons served as controls using fMRI with visual stimulation. In addition to a reduced activated volume, patients showed...

  2. Retinol Dehydrogenases Regulate Vitamin A Metabolism for Visual Function

    Directory of Open Access Journals (Sweden)

    Bhubanananda Sahu

    2016-11-01

    Full Text Available The visual system produces visual chromophore, 11-cis-retinal from dietary vitamin A, all-trans-retinol making this vitamin essential for retinal health and function. These metabolic events are mediated by a sequential biochemical process called the visual cycle. Retinol dehydrogenases (RDHs are responsible for two reactions in the visual cycle performed in retinal pigmented epithelial (RPE cells, photoreceptor cells and Müller cells in the retina. RDHs in the RPE function as 11-cis-RDHs, which oxidize 11-cis-retinol to 11-cis-retinal in vivo. RDHs in rod photoreceptor cells in the retina work as all-trans-RDHs, which reduce all-trans-retinal to all-trans-retinol. Dysfunction of RDHs can cause inherited retinal diseases in humans. To facilitate further understanding of human diseases, mouse models of RDHs-related diseases have been carefully examined and have revealed the physiological contribution of specific RDHs to visual cycle function and overall retinal health. Herein we describe the function of RDHs in the RPE and the retina, particularly in rod photoreceptor cells, their regulatory properties for retinoid homeostasis and future therapeutic strategy for treatment of retinal diseases.

  3. Changes in visual function during the Coriolis illusion.

    Science.gov (United States)

    Horng, Chi-Ting; Liu, Chung-Cheng; Kuo, Daih-Iluang; Shieh, Po-Chuen; Wu, Yi-Chang; Chen, Jiann-Torng; Tsai, Ming-Ling

    2009-04-01

    The Coriolis illusion produces spatial disorientation and is, therefore, dangerous for pilots. It is not known whether it also affects visual function (visual acuity and stereopsis). There were 18 subjects (15 men and 3 women, mean age 24.7 yr) enrolled in the study. A spatial disorientation simulator was used to produce Coriolis stimulation. The visual acuity of the subjects was evaluated with the Rosenbaum Vision Card before and during Coriolis stimulation. Stereopsis was measured with the Titmus stereo test. Throughout the experiments, eyeball movements were observed on a television monitor. Electrooculography (EOG) and electroencephalography (EEG) were also documented. Before Coriolis stimulation, the visual acuity and stereopsis of all subjects were 20/20 and 40 s of arc, respectively. During the Coriolis illusion, the visual acuity of nine subjects (50%) remained 20/20, whereas the visual acuity of the others (50%) dropped by two lines. The stereopsis of most subjects (77.8%) decreased to 800 arc-seconds or less. Rhythmic nystagmus was observed, while EOG amplitudes were significantly elevated compared with those at baseline (9.41 +/- 0.26 microv2 and 8.45 +/- 0.36 microv2, respectively). EEG activity (frequency) was also greater than at baseline (13.15 +/- 0.84 Hz and 11.94 +/- 1.20 Hz, respectively; P < 0.05). During Coriolis stimulation, the visual acuity of the subjects remained stable, but their stereopsis was reduced. Further study is warranted.

  4. Mathematical modeling and visualization of functional neuroimages

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup

    This dissertation presents research results regarding mathematical modeling in the context of the analysis of functional neuroimages. Specifically, the research focuses on pattern-based analysis methods that recently have become popular analysis tools within the neuroimaging community. Such methods...... attempt to predict or decode experimentally defined cognitive states based on brain scans. The topics covered in the dissertation are divided into two broad parts: The first part investigates the relative importance of model selection on the brain patterns extracted form analysis models. Typical...... influence of model regularization parameter choices on the model generalization, the reliability of the spatial brain patterns extracted from the analysis model, and the ability of the model to identify relevant brain networks defining the underlying neural encoding of the experiment. We show that known...

  5. Mathematical modeling and visualization of functional neuroimages

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup

    This dissertation presents research results regarding mathematical modeling in the context of the analysis of functional neuroimages. Specifically, the research focuses on pattern-based analysis methods that recently have become popular within the neuroimaging community. Such methods attempt...... to predict or decode experimentally defined cognitive states based on brain scans. The topics covered in the dissertation are divided into two broad parts: The first part investigates the relative importance of model selection on the brain patterns extracted form analysis models. Typical neuroimaging data...... of model regularization parameter choices on the model generalization, the reliability of the spatial brain patterns extracted from the analysis model, and the ability of the resulting model to identify relevant brain networks defining the underlying neural encoding of the experiment. We show that known...

  6. Assessment of visual function during brain surgery near the visual cortex by intraoperative optical imaging.

    Science.gov (United States)

    Sobottka, Stephan B; Meyer, Tobias; Kirsch, Matthias; Reiss, Gilfe; Koch, Edmund; Morgenstern, Ute; Schackert, Gabriele

    2013-06-01

    Several functional brain imaging and mapping techniques have been used for the intraoperative identification and preservation of the sensory, motor, and speech areas of the brain. However, intraoperative monitoring and mapping of the visual function is less frequently performed in the clinical routine. To our knowledge, here we demonstrate for the first time that the individual visual cortex can be mapped to the brain surface using a contact-free optical camera system during brain surgery. Intraoperative optical imaging (IOI) was performed by visual stimulation of both eyes using stobe-light flashes. Images were acquired by a camera mounted to a standard surgical microscope. Activity maps could reproducibly be computed by detecting the blood volume-dependent signal changes of the exposed cortex. To the preliminary experience, the new technique seems to be suitable for mapping the visual function in any neurosurgical intervention that requires exposure of the visual cortex. However, the clinical relevance and reliability of the technique need to be confirmed in further studies.

  7. The impact of structural and functional parameters in glaucoma patients on patient-reported visual functioning.

    Directory of Open Access Journals (Sweden)

    Christoph Hirneiß

    Full Text Available BACKGROUND: To evaluate the impact of structural changes of the retinal nerve fiber layer (RNFL, and visual field loss, on functional impairment assessed by patient-reported visual functioning in glaucoma. METHODS: Patients with glaucomatous optic nerve damage were enrolled in this cross-sectional study. Peripapillary RNFL thickness was obtained with spectral-domain optical coherence tomography (SD-OCT. Function was assessed by patient-reported visual functioning using the Rasch-calibrated Glaucoma Activity Limitation 9 (GAL-9 questionnaire and standard automated perimetry. The impact of peripapillary RNFL loss on functional impairment was analyzed with correlation and linear regression analyses. RESULTS: A total of 176 eyes from 88 glaucoma patients were included. The SD-OCT assessed temporal-superior and temporal-inferior RNFL sector of the worse eye revealed significant correlation with the GAL-9 scores (r=-0.298, p=0.011 and r=-0.251, p=0.033, respectively. In mutivariate regression analysis, the best predictors for patient-reported visual functioning were visual acuity of the better eye and mean defect of the worse eye (R(2=0.334, while structural parameters could not enhance the prediction of GAL-9 scores. CONCLUSIONS: Self-reported visual functioning of patients with glaucoma is better predicted by visual performance data than structural parameters. However, some structural changes of the worse eye are significantly correlated with patient-reported visual functioning.

  8. Visual function affects prosocial behaviors in older adults.

    Science.gov (United States)

    Teoli, Dac A; Smith, Merideth D; Leys, Monique J; Jain, Priyanka; Odom, J Vernon

    2016-02-01

    Eye-related pathological conditions such as glaucoma, diabetic retinopathy, and age-related macular degeneration commonly lead to decreased peripheral/central field, decreased visual acuity, and increased functional disability. We sought to answer if relationships exist between measures of visual function and reported prosocial behaviors in an older adult population with eye-related diagnoses. The sample consisted of adults, aged ≥ 60 years old, at an academic hospital's eye institute. Vision ranged from normal to severe impairment. Medical charts determined the visual acuities, ocular disease, duration of disease (DD), and visual fields (VF). Measures of giving help were via validated questionnaires on giving formal support (GFS) and giving informal support; measures of help received were perceived support (PS) and informal support received (ISR). ISR had subscales: tangible support (ISR-T), emotional support (ISR-E), and composite (ISR-C). Visual acuities of the better and worse seeing eyes were converted to LogMAR values. VF information converted to a 4-point rating scale of binocular field loss severity. DD was in years. Among 96 participants (mean age 73.28; range 60-94), stepwise regression indicated a relationship of visual variables to GFS (p < 0.05; Multiple R (2) = 0.1679 with acuity-better eye, VF rating, and DD), PS (p < 0.05; Multiple R (2) = 0.2254 with acuity-better eye), ISR-C (p < 0.05; Multiple R (2) = 0.041 with acuity-better eye), and ISR-T (p < 0.05; Multiple R (2) = 0.1421 with acuity-better eye). The findings suggest eye-related conditions can impact levels and perceptions of support exchanges. Our data reinforces the importance of visual function as an influence on prosocial behavior in older adults.

  9. The multisensory function of the human primary visual cortex.

    Science.gov (United States)

    Murray, Micah M; Thelen, Antonia; Thut, Gregor; Romei, Vincenzo; Martuzzi, Roberto; Matusz, Pawel J

    2016-03-01

    It has been nearly 10 years since Ghazanfar and Schroeder (2006) proposed that the neocortex is essentially multisensory in nature. However, it is only recently that sufficient and hard evidence that supports this proposal has accrued. We review evidence that activity within the human primary visual cortex plays an active role in multisensory processes and directly impacts behavioural outcome. This evidence emerges from a full pallet of human brain imaging and brain mapping methods with which multisensory processes are quantitatively assessed by taking advantage of particular strengths of each technique as well as advances in signal analyses. Several general conclusions about multisensory processes in primary visual cortex of humans are supported relatively solidly. First, haemodynamic methods (fMRI/PET) show that there is both convergence and integration occurring within primary visual cortex. Second, primary visual cortex is involved in multisensory processes during early post-stimulus stages (as revealed by EEG/ERP/ERFs as well as TMS). Third, multisensory effects in primary visual cortex directly impact behaviour and perception, as revealed by correlational (EEG/ERPs/ERFs) as well as more causal measures (TMS/tACS). While the provocative claim of Ghazanfar and Schroeder (2006) that the whole of neocortex is multisensory in function has yet to be demonstrated, this can now be considered established in the case of the human primary visual cortex.

  10. Neuroanatomical changes in patients with loss of visual function

    NARCIS (Netherlands)

    Prins, Doety

    2016-01-01

    Eye diseases that cause loss of visual function are associated with changes in the brain. However, the underlying mechanism of this association is still unclear. Research into this association is important, since the remaining capacity of the brain to conduct and process the input from the eye is

  11. Visualization techniques for spatial probability density function data

    Directory of Open Access Journals (Sweden)

    Udeepta D Bordoloi

    2006-01-01

    Full Text Available Novel visualization methods are presented for spatial probability density function data. These are spatial datasets, where each pixel is a random variable, and has multiple samples which are the results of experiments on that random variable. We use clustering as a means to reduce the information contained in these datasets; and present two different ways of interpreting and clustering the data. The clustering methods are used on two datasets, and the results are discussed with the help of visualization techniques designed for the spatial probability data.

  12. Functional Connectivity Between Superior Parietal Lobule and Primary Visual Cortex "at Rest" Predicts Visual Search Efficiency.

    Science.gov (United States)

    Bueichekú, Elisenda; Ventura-Campos, Noelia; Palomar-García, María-Ángeles; Miró-Padilla, Anna; Parcet, María-Antonia; Ávila, César

    2015-10-01

    Spatiotemporal activity that emerges spontaneously "at rest" has been proposed to reflect individual a priori biases in cognitive processing. This research focused on testing neurocognitive models of visual attention by studying the functional connectivity (FC) of the superior parietal lobule (SPL), given its central role in establishing priority maps during visual search tasks. Twenty-three human participants completed a functional magnetic resonance imaging session that featured a resting-state scan, followed by a visual search task based on the alphanumeric category effect. As expected, the behavioral results showed longer reaction times and more errors for the within-category (i.e., searching a target letter among letters) than the between-category search (i.e., searching a target letter among numbers). The within-category condition was related to greater activation of the superior and inferior parietal lobules, occipital cortex, inferior frontal cortex, dorsal anterior cingulate cortex, and the superior colliculus than the between-category search. The resting-state FC analysis of the SPL revealed a broad network that included connections with the inferotemporal cortex, dorsolateral prefrontal cortex, and dorsal frontal areas like the supplementary motor area and frontal eye field. Noteworthy, the regression analysis revealed that the more efficient participants in the visual search showed stronger FC between the SPL and areas of primary visual cortex (V1) related to the search task. We shed some light on how the SPL establishes a priority map of the environment during visual attention tasks and how FC is a valuable tool for assessing individual differences while performing cognitive tasks.

  13. Functional and anatomical properties of human visual cortical fields.

    Science.gov (United States)

    Zhang, Shouyu; Cate, Anthony D; Herron, Timothy J; Kang, Xiaojian; Yund, E William; Bao, Shanglian; Woods, David L

    2015-04-01

    Human visual cortical fields (VCFs) vary in size and anatomical location across individual subjects. Here, we used functional magnetic resonance imaging (fMRI) with retinotopic stimulation to identify VCFs on the cortical surface. We found that aligning and averaging VCF activations across the two hemispheres provided clear delineation of multiple retinotopic fields in visual cortex. The results show that VCFs have consistent locations and extents in different subjects that provide stable and accurate landmarks for functional and anatomical mapping. Interhemispheric comparisons revealed minor differences in polar angle and eccentricity tuning in comparable VCFs in the left and right hemisphere, and somewhat greater intersubject variability in the right than left hemisphere. We then used the functional boundaries to characterize the anatomical properties of VCFs, including fractional anisotropy (FA), magnetization transfer ratio (MTR) and the ratio of T1W and T2W images and found significant anatomical differences between VCFs and between hemispheres.

  14. Hierarchical organization of brain functional network during visual task

    CERN Document Server

    Zhuo, Zhao; Fu, Zhong-Qian; Zhang, Jie

    2011-01-01

    In this paper, the brain functional networks derived from high-resolution synchronous EEG time series during visual task are generated by calculating the phase synchronization among the time series. The hierarchical modular organizations of these networks are systematically investigated by the fast Girvan-Newman algorithm. At the same time, the spatially adjacent electrodes (corresponding to EEG channels) are clustered into functional groups based on anatomical parcellation of brain cortex, and this clustering information are compared to that of the functional network. The results show that the modular architectures of brain functional network are in coincidence with that from the anatomical structures over different levels of hierarchy, which suggests that population of neurons performing the same function excite and inhibit in identical rhythms. The structure-function relationship further reveals that the correlations among EEG time series in the same functional group are much stronger than those in differe...

  15. How Visual Is the Visual Cortex? Comparing Connectional and Functional Fingerprints between Congenitally Blind and Sighted Individuals.

    Science.gov (United States)

    Wang, Xiaoying; Peelen, Marius V; Han, Zaizhu; He, Chenxi; Caramazza, Alfonso; Bi, Yanchao

    2015-09-09

    Classical animal visual deprivation studies and human neuroimaging studies have shown that visual experience plays a critical role in shaping the functionality and connectivity of the visual cortex. Interestingly, recent studies have additionally reported circumscribed regions in the visual cortex in which functional selectivity was remarkably similar in individuals with and without visual experience. Here, by directly comparing resting-state and task-based fMRI data in congenitally blind and sighted human subjects, we obtained large-scale continuous maps of the degree to which connectional and functional "fingerprints" of ventral visual cortex depend on visual experience. We found a close agreement between connectional and functional maps, pointing to a strong interdependence of connectivity and function. Visual experience (or the absence thereof) had a pronounced effect on the resting-state connectivity and functional response profile of occipital cortex and the posterior lateral fusiform gyrus. By contrast, connectional and functional fingerprints in the anterior medial and posterior lateral parts of the ventral visual cortex were statistically indistinguishable between blind and sighted individuals. These results provide a large-scale mapping of the influence of visual experience on the development of both functional and connectivity properties of visual cortex, which serves as a basis for the formulation of new hypotheses regarding the functionality and plasticity of specific subregions. Significance statement: How is the functionality and connectivity of the visual cortex shaped by visual experience? By directly comparing resting-state and task-based fMRI data in congenitally blind and sighted subjects, we obtained large-scale continuous maps of the degree to which connectional and functional "fingerprints" of ventral visual cortex depend on visual experience. In addition to revealing regions that are strongly dependent on visual experience (early visual

  16. Dynamic functional brain networks involved in simple visual discrimination learning.

    Science.gov (United States)

    Fidalgo, Camino; Conejo, Nélida María; González-Pardo, Héctor; Arias, Jorge Luis

    2014-10-01

    Visual discrimination tasks have been widely used to evaluate many types of learning and memory processes. However, little is known about the brain regions involved at different stages of visual discrimination learning. We used cytochrome c oxidase histochemistry to evaluate changes in regional brain oxidative metabolism during visual discrimination learning in a water-T maze at different time points during training. As compared with control groups, the results of the present study reveal the gradual activation of cortical (prefrontal and temporal cortices) and subcortical brain regions (including the striatum and the hippocampus) associated to the mastery of a simple visual discrimination task. On the other hand, the brain regions involved and their functional interactions changed progressively over days of training. Regions associated with novelty, emotion, visuo-spatial orientation and motor aspects of the behavioral task seem to be relevant during the earlier phase of training, whereas a brain network comprising the prefrontal cortex was found along the whole learning process. This study highlights the relevance of functional interactions among brain regions to investigate learning and memory processes. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Real-time functional architecture of visual word recognition.

    Science.gov (United States)

    Whiting, Caroline; Shtyrov, Yury; Marslen-Wilson, William

    2015-02-01

    Despite a century of research into visual word recognition, basic questions remain unresolved about the functional architecture of the process that maps visual inputs from orthographic analysis onto lexical form and meaning and about the units of analysis in terms of which these processes are conducted. Here we use magnetoencephalography, supported by a masked priming behavioral study, to address these questions using contrasting sets of simple (walk), complex (swimmer), and pseudo-complex (corner) forms. Early analyses of orthographic structure, detectable in bilateral posterior temporal regions within a 150-230 msec time frame, are shown to segment the visual input into linguistic substrings (words and morphemes) that trigger lexical access in left middle temporal locations from 300 msec. These are primarily feedforward processes and are not initially constrained by lexical-level variables. Lexical constraints become significant from 390 msec, in both simple and complex words, with increased processing of pseudowords and pseudo-complex forms. These results, consistent with morpho-orthographic models based on masked priming data, map out the real-time functional architecture of visual word recognition, establishing basic feedforward processing relationships between orthographic form, morphological structure, and lexical meaning.

  18. Dyspraxia, motor function and visual-motor integration in autism.

    Science.gov (United States)

    Miller, M; Chukoskie, L; Zinni, M; Townsend, J; Trauner, D

    2014-08-01

    This project assessed dyspraxia in high-functioning school aged children with autism with a focus on Ideational Praxis. We examined the association of specific underlying motor function including eye movement with ideational dyspraxia (sequences of skilled movements) as well as the possible role of visual-motor integration in dyspraxia. We found that compared to IQ-, sex- and age-matched typically developing children, the children with autism performed significantly worse on: Ideational and Buccofacial praxis; a broad range of motor tests, including measures of simple motor skill, timing and accuracy of saccadic eye movements and motor coordination; and tests of visual-motor integration. Impairments in individual children with autism were heterogeneous in nature, although when we examined the praxis data as a function of a qualitative measure representing motor timing, we found that children with poor motor timing performed worse on all praxis categories and had slower and less accurate eye movements while those with regular timing performed as well as typical children on those same tasks. Our data provide evidence that both motor function and visual-motor integration contribute to dyspraxia. We suggest that dyspraxia in autism involves cerebellar mechanisms of movement control and the integration of these mechanisms with cortical networks implicated in praxis.

  19. GPView: A program for wave function analysis and visualization.

    Science.gov (United States)

    Shi, Tian; Wang, Ping

    2016-11-01

    In this manuscript, we will introduce a recently developed program GPView, which can be used for wave function analysis and visualization. The wave function analysis module can calculate and generate 3D cubes for various types of molecular orbitals and electron density of electronic excited states, such as natural orbitals, natural transition orbitals, natural difference orbitals, hole-particle density, detachment-attachment density and transition density. The visualization module of GPView can display molecular and electronic (iso-surfaces) structures. It is also able to animate single trajectories of molecular dynamics and non-adiabatic excited state molecular dynamics using the data stored in existing files. There are also other utilities to extract and process the output of quantum chemistry calculations. The GPView provides full graphic user interface (GUI), so it very easy to use. It is available from website http://life-tp.com/gpview.

  20. GPView: a program for wave function analysis and visualization

    CERN Document Server

    Shi, Tian

    2016-01-01

    In this manuscript, we will introduce a recently developed program GPView, which can be used for wave function analysis and visualization. The wave function analysis module can calculate and generate 3D cubes for various types of molecular orbitals and electron density related with electronic excited states, such as natural orbitals, natural transition orbitals, natural difference orbitals, hole-particle density, detachment-attachment density and transition density. The visualization module of GPView can display molecular and electronic (iso-surfaces) structures. It is also able to animate single trajectories of molecular dynamics and non-adiabatic excited state molecular dynamics using the data stored in existing files. There are also other utilities help to extract and process the output of quantum chemistry calculations. The GPView provides full graphic user interface (GUI) which makes it very easy to use. The software, manual and tutorials are available in the website http://www.life-tp.com/gpview.

  1. Visual steady state in relation to age and cognitive function

    DEFF Research Database (Denmark)

    Horwitz, Anna; Dyhr Thomsen, Mia; Wiegand, Iris

    2017-01-01

    examine the steady-state VEP power response (SSVEP-PR) in the alpha (8Hz) and gamma (36Hz) bands in 54 males (avg. age: 62.0 years) and compare these with 10 young healthy participants (avg. age 27.6 years). Furthermore, we correlate the individual alpha-to-gamma difference in relative visual-area power......, global cognition, executive function, memory, and education (p

  2. Differential functioning of Bender Visual-Motor Gestalt Test items.

    Science.gov (United States)

    Sisto, Fermino Fernandes; Dos Santos, Acácia Aparecida Angeli; Noronha, Ana Paula Porto

    2010-02-01

    Differential Item Functioning (DIF) refers to items that do not function the same way for comparable members of different groups. The present study focuses on analyzing and classifying sex-related differential item functioning in the Bender Visual-Motor Gestalt Test. Subjects were 1,052 children attending public schools (513 boys, 539 girls, ages 6-10 years). The protocols were scored using the Bender Graduated Scoring System, which evaluates only the distortion criterion using the Rasch logistic response model. The scoring system fit the Rasch model, although two items were found to be biased by sex. When analyzing differential functioning of items for boys and girls separately, the number of differentially functioning items was equal.

  3. Functional Literacy for Students with Visual Impairments and Significant Cognitive Disabilities: The Perspective of Teachers of Students with Visual Impairments

    Science.gov (United States)

    Zebehazy, Kim T.

    2014-01-01

    This study reports opinions and practices of teachers of students with visual impairments (TSVIs) in 34 states regarding functional literacy for students with visual impairments (VIs) and significant cognitive disabilities (SCDs). The survey asked TSVIs to select a definition of functional literacy, indicate agreement with a series of literacy…

  4. 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.

  5. Rasch Measurement Analysis of a 25-Item Version of the Mueller/McCloskey Nurse Job Satisfaction Scale in a Sample of Nurses in Lebanon and Qatar

    Directory of Open Access Journals (Sweden)

    Michael Clinton

    2015-06-01

    Full Text Available The Mueller/McCloskey Nurse Job Satisfaction Scale (MMSS is widely used, but its psychometric characteristics have not been sufficiently validated for use in Middle Eastern countries. The objective of our methodological study was to determine the psychometric suitability of a 25-item version of the MMSS (MMSS-25 for use in middle-income and high-income Middle Eastern countries. A total of 1,322 registered nurses, 859 in Lebanon and 463 in Qatar, completed the MMSS-25 as part of a cross-sectional multinational investigation of nursing shortages in the region. We used the Rasch rating scale model to investigate the psychometric performance of the MMSS-25. We identified possible item bias among MMSS-25 items. We conducted confirmatory factor analyses (CFA to compare the fit to our data of five factor structures reported in the literature. We concluded that irrespective of administration in English or Arabic, the MMSS-25 is not sufficiently productive of measurement for use in the region. A core set of 13 items (MMSS-13, Cronbach’s α = .82 loading on five dimensions eliminates redundant MMSS items and is suitable for initial screening of nurses’ satisfaction. Of the five factor structures we examined, the MMSS-13 was the only close fit to our data (comparative fit index = 0.951; Tucker–Lewis index = 0.931; root mean square error of approximation = 0.051; p value = .401. The MMSS-13 has psychometric characteristics superior to MMSS-25, but additional items are required to meet the research-specific objectives of future studies of nurses’ job satisfaction in Middle Eastern countries.

  6. Visualization

    OpenAIRE

    Balon, Andreja

    1990-01-01

    The present thesis entails the field of visualization which is divided into visualization along traditional lines and visualization in computer science. As the psychological aspect of image is of vital importance for visualization, it is shortly described in the beginning. Visualization in computer science is divided into three main fields: scientific visualization, program visualization and visual programming. An explanation and examples of approach to applications are given for each field....

  7. Visual function alterations in essential tremor: A case report

    Directory of Open Access Journals (Sweden)

    David P. Piñero

    2015-09-01

    Full Text Available Our purpose is to report alterations in contrast sensitivity function (CSF and in the magno, parvo and koniocellular visual pathways by means of a multichannel perimeter in case of an essential tremor (ET. A complete evaluation of the visual function was performed in a 69-year old patient, including the analysis of the chromatic discrimination by the Fansworth–Munsell 100 hue test, the measurement of the CSF by the CSV-1000E test, and the detection of potential alteration patterns in the magno, parvo and koniocellular visual pathways by means of a multichannel perimeter. Visual acuity and intraocular pressure (IOP were within the ranges of normality in both eyes. No abnormalities were detected in the fundoscopic examination and in the optical coherence tomography (OCT exam. The results of the color vision examination were also within the ranges of normality. A significant decrease in the achromatic CSFs for right eye (RE and left eye (LE was detected for all spatial frequencies. The statistical global values provided by the multichannel perimeter confirms that there were significant absolute sensitivity losses compared to the normal pattern in RE. In the LE, only a statistically significant decrease in sensitivity was detected for the blue-yellow (BY channel. The pattern standard deviation (PSD values obtained in our patient indicated that there were significant localized losses compared to the normality pattern in the achromatic channel of the RE and in the red-green (RG channel of the LE. Some color vision alterations may be present in ET that cannot be detected with conventional color vision tests, such as the FM 100 Hue.

  8. Perceptual learning modifies the functional specializations of visual cortical areas.

    Science.gov (United States)

    Chen, Nihong; Cai, Peng; Zhou, Tiangang; Thompson, Benjamin; Fang, Fang

    2016-05-17

    Training can improve performance of perceptual tasks. This phenomenon, known as perceptual learning, is strongest for the trained task and stimulus, leading to a widely accepted assumption that the associated neuronal plasticity is restricted to brain circuits that mediate performance of the trained task. Nevertheless, learning does transfer to other tasks and stimuli, implying the presence of more widespread plasticity. Here, we trained human subjects to discriminate the direction of coherent motion stimuli. The behavioral learning effect substantially transferred to noisy motion stimuli. We used transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) to investigate the neural mechanisms underlying the transfer of learning. The TMS experiment revealed dissociable, causal contributions of V3A (one of the visual areas in the extrastriate visual cortex) and MT+ (middle temporal/medial superior temporal cortex) to coherent and noisy motion processing. Surprisingly, the contribution of MT+ to noisy motion processing was replaced by V3A after perceptual training. The fMRI experiment complemented and corroborated the TMS finding. Multivariate pattern analysis showed that, before training, among visual cortical areas, coherent and noisy motion was decoded most accurately in V3A and MT+, respectively. After training, both kinds of motion were decoded most accurately in V3A. Our findings demonstrate that the effects of perceptual learning extend far beyond the retuning of specific neural populations for the trained stimuli. Learning could dramatically modify the inherent functional specializations of visual cortical areas and dynamically reweight their contributions to perceptual decisions based on their representational qualities. These neural changes might serve as the neural substrate for the transfer of perceptual learning.

  9. Successful tactile based visual sensory substitution use functions independently of visual pathway integrity

    Directory of Open Access Journals (Sweden)

    Vincent eLee

    2014-05-01

    Full Text Available Purpose: We explored the microstructural differences between perinatally blind (PB, acquired blind (AB, and normally sighted controls (SC and related these differences to performance on functional tasks using a sensory substitution device (BrainPort. Methods: We enrolled 52 subjects (PB n=11; AQ n=35; NS n=6. Subjects spent 15 hours undergoing BrainPort device training. Outcomes of light perception, motion, direction, temporal resolution, grating, and acuity were tested at baseline and after training. Twenty-six of the subjects were scanned with a 3 Tesla MRI scanner for diffusion tensor imaging (DTI, and with a positron emission tomography (PET scanner for mapping regional brain glucose consumption during sensory substitution function. Non-parametric models were used to analyze fractional anisotropy (FA; a DTI measure of microstructural integrity of the brain via region-of-interest (ROI analysis and tract-based spatial statistics (TBSS. Results: At baseline, all subjects performed all tasks at chance level. After training, light perception, time resolution, location and grating acuity tasks improved significantly for all subject groups. ROI and TBSS analyses of FA maps show statistically significant differences (p≤0.025 in the bilateral optic radiations and some visual association areas between all 3 groups. No relationship was found between FA and functional performance with the BrainPort. Discussion: : All subjects showed performance improvements using the BrainPort irrespective of nature and duration of blindness. Definite brain areas with significant microstructural integrity changes exist among PB, AB, and NC, and these variations are most pronounced in the visual pathways. However, the use of sensory substitution devices is feasible irrespective of of microstructural integrity of the primary visual pathways between the eye and the brain. Therefore, tongue based devices devices may be usable for a broad array of non sighted persons.

  10. Modeling Visual Symptoms and Visual Skills to Measure Functional Binocular Vision

    Science.gov (United States)

    Powers, M. K.; Fisher, W. P., Jr.; Massof, R. W.

    2016-11-01

    Obtaining a clear image of the world depends on good eye coordination (“binocular vision”). Yet no standard exists by which to determine a threshold for good vs poor binocular vision, as exists for the eye chart and visual acuity. We asked whether data on the signs and symptoms related to binocular vision are sufficiently consistent with children's self-reported visual symptoms to substantiate a construct model of Functional Binocular Vision (FBV), and then whether that model can be used to aggregate clinical and survey observations into a meaningful diagnostic measure. Data on visual symptoms from 1,100 children attending school in Los Angeles were obtained using the Convergence Insufficiency Symptom Survey (CISS); and for more than 300 students in that sample, 35 additional measures were taken, including acuity, cover test near and far, near point of convergence, near point of accommodation, accommodative facility, vergence ranges, tracking ability, and oral reading fluency. A preliminary analysis of data from the 15-item, 5-category CISS and 15 clinical variables from 103 grade school students who reported convergence problems (CISS scores of 16 or higher) suggests that the clinical and survey observations will be optimally combined in a multidimensional model.

  11. A Visual Interface Diagram For Mapping Functions In Integrated Products

    DEFF Research Database (Denmark)

    Ingerslev, Mattias; Oliver Jespersen, Mikkel; Göhler, Simon Moritz

    2015-01-01

    of visualizing relations between parts and functions in highly integrated mechanical products. The result is an interface diagram that supports design teams in communication, decision making and design management. The diagram gives the designer an overview of the couplings and dependencies within a product......In product development there is a recognized tendency towards increased functionality for each new product generation. This leads to more integrated and complex products, with the risk of development delays and quality issues as a consequence of lacking overview and transparency. The work described...... in this article has been conducted in collaboration with Novo Nordisk on the insulin injection device FlexTouch® as case product. The FlexTouch® reflects the characteristics of an integrated product with several functions shared between a relatively low number of parts. In this article we present a novel way...

  12. Novel in vivo techniques to visualize kidney anatomy and function.

    Science.gov (United States)

    Peti-Peterdi, János; Kidokoro, Kengo; Riquier-Brison, Anne

    2015-07-01

    Intravital imaging using multiphoton microscopy (MPM) has become an increasingly popular and widely used experimental technique in kidney research over the past few years. MPM allows deep optical sectioning of the intact, living kidney tissue with submicron resolution, which is unparalleled among intravital imaging approaches. MPM has solved a long-standing critical technical barrier in renal research to study several complex and inaccessible cell types and anatomical structures in vivo in their native environment. Comprehensive and quantitative kidney structure and function MPM studies helped our better understanding of the cellular and molecular mechanisms of the healthy and diseased kidney. This review summarizes recent in vivo MPM studies with a focus on the glomerulus and the filtration barrier, although select, glomerulus-related renal vascular and tubular functions are also mentioned. The latest applications of serial MPM of the same glomerulus in vivo, in the intact kidney over several days, during the progression of glomerular disease are discussed. This visual approach, in combination with genetically encoded fluorescent markers of cell lineage, has helped track the fate and function (e.g., cell calcium changes) of single podocytes during the development of glomerular pathologies, and provided visual proof for the highly dynamic, rather than static, nature of the glomerular environment. Future intravital imaging applications have the promise to further push the limits of optical microscopy, and to advance our understanding of the mechanisms of kidney injury. Also, MPM will help to study new mechanisms of tissue repair and regeneration, a cutting-edge area of kidney research.

  13. INTERACTIVE VISUALIZATION OF PROBABILITY AND CUMULATIVE DENSITY FUNCTIONS

    KAUST Repository

    Potter, Kristin

    2012-01-01

    The probability density function (PDF), and its corresponding cumulative density function (CDF), provide direct statistical insight into the characterization of a random process or field. Typically displayed as a histogram, one can infer probabilities of the occurrence of particular events. When examining a field over some two-dimensional domain in which at each point a PDF of the function values is available, it is challenging to assess the global (stochastic) features present within the field. In this paper, we present a visualization system that allows the user to examine two-dimensional data sets in which PDF (or CDF) information is available at any position within the domain. The tool provides a contour display showing the normed difference between the PDFs and an ansatz PDF selected by the user and, furthermore, allows the user to interactively examine the PDF at any particular position. Canonical examples of the tool are provided to help guide the reader into the mapping of stochastic information to visual cues along with a description of the use of the tool for examining data generated from an uncertainty quantification exercise accomplished within the field of electrophysiology.

  14. Higher visual functions in the upper and lower visual fields: A pilot study in healthy subjects.

    Science.gov (United States)

    Zito, Giuseppe A; Muri, Rene; Mosimann, Urs P; Nyffeler, Thomas; Nef, Tobias

    2015-01-01

    Visual perception is not identical in the upper and lower visual hemifields. The mechanisms behind this difference can be found at the retinal, cortical, or higher attentional level. In this study, a new visual test battery, that involves real-time comparisons of complex visual stimuli, such as shape of objects, and speed of moving dot patterns, in the upper and lower visual hemifields, is presented. This study represents, to our knowledge, the first to implement such a visual test battery in an immersive environment composed of a hemisphere, in order to present visual stimuli in precise regions of the visual field. Ten healthy volunteers were tested in this pilot study. The results showed a higher accuracy in the image matching when the visual test was performed in the lower visual hemifield.

  15. Functional implications of orientation maps in primary visual cortex

    Science.gov (United States)

    Koch, Erin; Jin, Jianzhong; Alonso, Jose M.; Zaidi, Qasim

    2016-11-01

    Stimulus orientation in the primary visual cortex of primates and carnivores is mapped as iso-orientation domains radiating from pinwheel centres, where orientation preferences of neighbouring cells change circularly. Whether this orientation map has a function is currently debated, because many mammals, such as rodents, do not have such maps. Here we show that two fundamental properties of visual cortical responses, contrast saturation and cross-orientation suppression, are stronger within cat iso-orientation domains than at pinwheel centres. These differences develop when excitation (not normalization) from neighbouring oriented neurons is applied to different cortical orientation domains and then balanced by inhibition from un-oriented neurons. The functions of the pinwheel mosaic emerge from these local intra-cortical computations: Narrower tuning, greater cross-orientation suppression and higher contrast gain of iso-orientation cells facilitate extraction of object contours from images, whereas broader tuning, greater linearity and less suppression of pinwheel cells generate selectivity for surface patterns and textures.

  16. Proteins of the corneal stroma: importance in visual function.

    Science.gov (United States)

    Xuan, Meng; Wang, Shurong; Liu, Xin; He, Yuxi; Li, Ying; Zhang, Yan

    2016-04-01

    The human cornea, consisting of five layers, is the transparent tissue that refracts and transmits light to the lens and retina, providing about two thirds of the refractive power of the eye. The stroma layer comprises nearly 90 % of the thickness of the cornea and thus plays a pivotal role in normal visual function. The bulk of this layer is constituted by proteins in the extracellular martrix secreted by the corneal epithelial, stroma, and endothelial cells. Clinical research has shown that corneal stroma diseases are common and involve conditions such as infections, injuries, and genetic defects, which cause severe visual disturbances or even blindness. To improve our understanding of the basic molecular mechanisms involved in the physiological and pathological activities of the corneal stroma, its proteins have been brought into the limelight to determine their crucial and irreplaceable roles. The data presented in a previous study have demonstrated the presence of 1679 proteins in the stroma, and this data set has subsequently been perfected by utilizing a highly sensitive isobaric peptide-labeling approach. According to their manifestations, these proteins can be classified as a gel-like organic material composed of proteoglycans, enzymes, and hemocyanin-binding proteins and a network of filaments composed of collagen, elastin, keratin, vimentin, and interconnected filaments comprising fibronectin and laminin. The aim of this review is to describe some corneal stroma proteins by highlighting their major functions and valuable applications in ophthalmologic research toward the better characterization and treatment of eye diseases.

  17. Windows into the Visual Brain: New Discoveries about the Visual System, Its Functions, and Implications for Practitioners

    Science.gov (United States)

    Jan, James E.; Heaven, Roberta K. B.; Matsuba, Carey; Langley, M. Beth; Roman-Lantzy, Christine; Anthony, Tanni L

    2013-01-01

    Introduction: In recent years, major progress has been made in understanding the human visual system because of new investigative techniques. These developments often contradict older concepts about visual function. Methods: A detailed literature search and interprofessional discussions. Results: Recent innovative neurological tests are described…

  18. Windows into the Visual Brain: New Discoveries about the Visual System, Its Functions, and Implications for Practitioners

    Science.gov (United States)

    Jan, James E.; Heaven, Roberta K. B.; Matsuba, Carey; Langley, M. Beth; Roman-Lantzy, Christine; Anthony, Tanni L

    2013-01-01

    Introduction: In recent years, major progress has been made in understanding the human visual system because of new investigative techniques. These developments often contradict older concepts about visual function. Methods: A detailed literature search and interprofessional discussions. Results: Recent innovative neurological tests are described…

  19. 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.

  20. The Reliability of the CVI Range: A Functional Vision Assessment for Children with Cortical Visual Impairment

    Science.gov (United States)

    Newcomb, Sandra

    2010-01-01

    Children who are identified as visually impaired frequently have a functional vision assessment as one way to determine how their visual impairment affects their educational performance. The CVI Range is a functional vision assessment for children with cortical visual impairment. The purpose of the study presented here was to examine the…

  1. The Reliability of the CVI Range: A Functional Vision Assessment for Children with Cortical Visual Impairment

    Science.gov (United States)

    Newcomb, Sandra

    2010-01-01

    Children who are identified as visually impaired frequently have a functional vision assessment as one way to determine how their visual impairment affects their educational performance. The CVI Range is a functional vision assessment for children with cortical visual impairment. The purpose of the study presented here was to examine the…

  2. Functional neuroimaging of visual creativity: a systematic review and meta‐analysis

    OpenAIRE

    2016-01-01

    Abstract Introduction The generation of creative visual imagery contributes to technological and scientific innovation and production of visual art. The underlying cognitive and neural processes are, however, poorly understood. Methods This review synthesizes functional neuroimaging studies of visual creativity. Seven functional magnetic resonance imaging (fMRI) and 19 electroencephalography (EEG) studies were included, comprising 27 experiments and around 800 participants. Results Activation...

  3. Visual function in preterm infants: visualizing the brain to improve prognosis.

    Science.gov (United States)

    Chau, Vann; Taylor, Margot J; Miller, Steven P

    2013-08-01

    Considerable development of the visual system occurs in the third trimester of life, a time when very preterm-born infants are in a neonatal intensive care unit (NICU). Their very early birth during a period of rapid and marked neurodevelopment and their clinical course makes them a very high-risk population. A range of different events impacts brain development and the visual system, leading to significant long-term visual dysfunction. Improved neuroimaging techniques provide an important window on the early brain and visual system development of these vulnerable infants. Greater understanding of the etiology of visual impairment subsequent to preterm birth and the timing of critical processes will allow early recognition and the earlier implementations of interventions. In the longer term, this will help clinicians optimize NICU practice to reduce the incidence of visual dysfunction in these children.

  4. Impact of low vision rehabilitation on functional vision performance of children with visual impairment

    Directory of Open Access Journals (Sweden)

    Suma Ganesh

    2013-01-01

    Conclusions: In our study group, there was a significant improvement in functional vision post visual rehabilitation, especially with those activities which are related to their academic output. It is important for these children to have an early visual rehabilitation to decrease the impairment associated with these decreased visual output and to enhance their learning abilities.

  5. Visual function in optic neuritis in relation to multiple sclerosis : an electrophysiological and psychophysical study

    NARCIS (Netherlands)

    J.C. van der Poel (Johanna Catarina)

    1985-01-01

    textabstractThe purpose of the present study is to assess the predictive value of visual function in ON patients with regard to the development of MS. For this purpose, idiopathic optic neuritis patients were seen during the acute stage of the attack and after improvement of visual acuity. Visual fu

  6. Visual function in optic neuritis in relation to multiple sclerosis : an electrophysiological and psychophysical study

    NARCIS (Netherlands)

    J.C. van der Poel (Johanna Catarina)

    1985-01-01

    textabstractThe purpose of the present study is to assess the predictive value of visual function in ON patients with regard to the development of MS. For this purpose, idiopathic optic neuritis patients were seen during the acute stage of the attack and after improvement of visual acuity. Visual fu

  7. Functional MRI of the visual cortex and visual testing in patients with previous optic neuritis

    DEFF Research Database (Denmark)

    Langkilde, Annika Reynberg; Frederiksen, J.L.; Rostrup, Egill

    2002-01-01

    to both the results of the contrast sensitivity test and to the Snellen visual acuity. Our results indicate that fMRI is a useful method for the study of ON, even in cases where the visual acuity is severely impaired. The reduction in activated volume could be explained as a reduced neuronal input...

  8. Students with Low Vision Describe Their Visual Impairments and Visual Functioning

    Science.gov (United States)

    Guerette, Amy R.; Lewis, Sandra; Mattingly, Cameron

    2011-01-01

    In the study reported here, the responses to a survey that was designed to determine the knowledge of their visual impairment of 51 students with low vision were analyzed. Although the students described their visual weaknesses and strengths, they had limited knowledge of, and difficulty communicating about, the medical aspects of their…

  9. Likert and Guttman scaling of visual function rating scale questionnaires.

    Science.gov (United States)

    Massof, Robert W

    2004-12-01

    To test the assumptions underlying Likert scoring of visual function questionnaires. Questionnaires were administered to 284 low-vision subjects by telephone. Each subject was administered two of four questionnaires: ADVS, NEI VFQ-25 plus supplement, expanded VAQ, and VF-14. Z-scores for cumulative frequency of using each rating category across subjects are not linear with rating category rank and items are not the same difficulty for any of the questionnaires. Guttmann coefficients of reproducibility ranged from 57% for the ADVS to 51% for the NEI VFQ-25. Cronbach alphas ranged from 0.92 for the VF-14 to 0.96 for the NEI VFQ; however, inter-item consistency coefficients ranged from 0.24 for the VAQ to 0.45 for the NEI VFQ. Likert scores were significantly correlated between instruments, ranging from 0.66 for NEI VFQ vs ADVS to 0.90 for the VF-14 vs. ADVS. The rating scales of all four questionnaires fail to satisfy Likert's assumptions. Also, ratings are probabilistic, rather than deterministic, which means that the Likert model is not valid for these questionnaires. However, Likert scores for all four instruments are intercorrelated, suggesting that they are monotonic with the latent subject trait distributed in the low vision sample.

  10. Visual steady state in relation to age and cognitive function

    Science.gov (United States)

    Dyhr Thomsen, Mia; Wiegand, Iris; Horwitz, Henrik; Klemp, Marc; Nikolic, Miki; Rask, Lene; Lauritzen, Martin; Benedek, Krisztina

    2017-01-01

    Neocortical gamma activity is crucial for sensory perception and cognition. This study examines the value of using non-task stimulation-induced EEG oscillations to predict cognitive status in a birth cohort of healthy Danish males (Metropolit) with varying cognitive ability. In particular, we examine the steady-state VEP power response (SSVEP-PR) in the alpha (8Hz) and gamma (36Hz) bands in 54 males (avg. age: 62.0 years) and compare these with 10 young healthy participants (avg. age 27.6 years). Furthermore, we correlate the individual alpha-to-gamma difference in relative visual-area power (ΔRV) with cognitive scores for the older adults. We find that ΔRV decrease with age by just over one standard deviation when comparing young with old participants (p<0.01). Furthermore, intelligence is significantly negatively correlated with ΔRV in the older adult cohort, even when processing speed, global cognition, executive function, memory, and education (p<0.05). In our preferred specification, an increase in ΔRV of one standard deviation is associated with a reduction in intelligence of 48% of a standard deviation (p<0.01). Finally, we conclude that the difference in cerebral rhythmic activity between the alpha and gamma bands is associated with age and cognitive status, and that ΔRV therefore provide a non-subjective clinical tool with which to examine cognitive status in old age. PMID:28245274

  11. VISUALIZATION APPROACH TO STRUCTURE-FUNCTION RELATIONSHIP IN BIOLOGICAL MACROMOLECULES

    Directory of Open Access Journals (Sweden)

    M. Luetić

    2015-08-01

    Full Text Available Introduction: Most of recent research in the field of education strongly recommends the use of visualization in the daily teacher’s practice, especially when it comes to teaching science. Objectives: We investigated the impact of different kinds of visualization on student’s accomplishments, and the relationship between 2D and 3D visualization on the learning outcomes in biochemistry teaching, as well as gender-related differences in 2D vs 3D perception abilities. Materials and Methods: The research study was conducted on a sample of 149 senior secondary school students, devided into three groups: control group (usual teaching approach, and two experimental groups taught using different kinds of visualization: E1 (2D and 3D static visualization tools, and E2 (3D dynamic visualization tools, in addition. Discussion and results: We measured the students’ learning outcomes in biochemistry, as well as the level of satisfaction with different teaching methods. The data were interpreted by performing statistical measures and analyses. In order to validate our hypothesis, we used one-tail and two-tail ANOVA analyses (along with the t-test.Conclusions: There was no statistical significance regarding 2D vs 3D visualization tools in biochemistry teaching. Although there existed some gender-related differences in students’ achievements (in favor of females, it was not established that they were related to the type of visualization (2D or 3D tools applied. However students from the E2 group (additional computer animations were more interested and involved in this kind of teaching. Although the results do not show a statistical significance in favor of 3D visualization, we must conclude that in teaching biochemistry it is certainly a more efficient approach than traditional teacher-oriented lessons. By using this kind of visualization tools in everyday teaching practice, chemistry teachers are given the opportunity to enlighten students with somewhat

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

    Science.gov (United States)

    Jia, Lina; Shi, Zhuanghua; Feng, Wenfeng

    2015-01-01

    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 duration 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 congruent 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.

  13. Graphical illustration and functional neuroimaging of visual hallucinations during prolonged blindfolding: a comparison to visual imagery.

    Science.gov (United States)

    Sireteanu, Ruxandra; Oertel, Viola; Mohr, Harald; Linden, David; Singer, Wolf

    2008-01-01

    Visual hallucinations can occur in healthy subjects during prolonged visual deprivation. We investigated the visual percepts and the associated brain activity in a 37-year-old healthy female subject who developed visual hallucinations during three weeks of blindfolding, and then compared this activity with the cortical activity associated with mental imagery of the same patterns. We acquired fMRI data with a Siemens 3T Magnetom Allegra towards the end of the deprivation period to assess hallucination-related activity, and again after recovery from blindfolding to measure imagery-related activity. Detailed subjective descriptions and graphical illustrations were provided by the subject after blindfolding was completed. The subject reported the occurrence of simple and elementary hallucinations, consisting of flashes and coloured and moving patterns during the period of blindfolding. Neural activity related to hallucinations was found in extrastriate occipital, posterior parietal, and several prefrontal regions. In contrast, mental imagery of the same percepts led to activation in prefrontal, but not in posterior, parietal, and occipital regions. These results suggest that deprivation-induced hallucinations result from increased excitability of extrastriate visual areas, while mentally induced imagery involves active read-out under the volitional control of prefrontal structures. This agrees with the subject's report that visual hallucinations were more vivid than mental imagery.

  14. 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.

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

    OpenAIRE

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

    2016-01-01

    Purpose To investigate the relationship between macular pigment (MP) and visual function in subjects with early age-related macular degeneration (AMD). Methods 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 disa...

  16. Glaucoma patients' assessment of their visual function and quality of life.

    OpenAIRE

    Jampel, H D

    2001-01-01

    PURPOSE: To determine how glaucoma patients with various degrees of vision loss rate their vision, and to determine if the Esterman binocular visual field test and other visual function tests correlate with those ratings. METHODS: Two hundred thirty-seven glaucoma patients evaluated their vision using 2 utility tests, the linear rating scale and the time trade-off test, and 2 quality-of-life instruments, the National Eye Institute Visual Function Questionnaire (VFQ) and the Short Form 36 (SF-...

  17. Visual Functions and TraceElement Metabolism in Tobacco-toxic Optic Neuropathy

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    Visual functions and nutrition metabolic characteristics werestudied in 8 subjects(16 eyes)with tobacco-toxic optic neuropathy(TTON).Their visual functions tested by psychophysical and electrophysiologicmethods showed that:1.central vision diminished in 16 eyes,2.dyschromatopsias were found in 14 tested eyes,3.bilateral symmetricalcentral or cecocentral scotomas were the visual field characteristics in allcases,4.PVEP were severe abnormal in 3 spatial frequencies in all cases and56.3% of 15' checkboard ...

  18. Structural and functional correlates of visual field asymmetry in the human brain by diffusion kurtosis MRI and functional MRI.

    Science.gov (United States)

    O'Connell, Caitlin; Ho, Leon C; Murphy, Matthew C; Conner, Ian P; Wollstein, Gadi; Cham, Rakie; Chan, Kevin C

    2016-11-09

    Human visual performance has been observed to show superiority in localized regions of the visual field across many classes of stimuli. However, the underlying neural mechanisms remain unclear. This study aims to determine whether the visual information processing in the human brain is dependent on the location of stimuli in the visual field and the corresponding neuroarchitecture using blood-oxygenation-level-dependent functional MRI (fMRI) and diffusion kurtosis MRI, respectively, in 15 healthy individuals at 3 T. In fMRI, visual stimulation to the lower hemifield showed stronger brain responses and larger brain activation volumes than the upper hemifield, indicative of the differential sensitivity of the human brain across the visual field. In diffusion kurtosis MRI, the brain regions mapping to the lower visual field showed higher mean kurtosis, but not fractional anisotropy or mean diffusivity compared with the upper visual field. These results suggested the different distributions of microstructural organization across visual field brain representations. There was also a strong positive relationship between diffusion kurtosis and fMRI responses in the lower field brain representations. In summary, this study suggested the structural and functional brain involvements in the asymmetry of visual field responses in humans, and is important to the neurophysiological and psychological understanding of human visual information processing.

  19. Visual function and retinal vessel diameters during hyperthermia in man.

    Science.gov (United States)

    Jensen, Bettina Hagström; Bram, Thue; Kappelgaard, Per; Arvidsson, Henrik; Loskutova, Ekaterina; Munch, Inger Christine; Larsen, Michael

    2016-12-21

    To assess the effect of elevated core body temperature on temporal and spatial contrast sensitivity and retinal vessel diameters. The study included 13 healthy volunteers aged 20-37 years. Core body temperature elevation (target +1.1°C) was induced by wrapping the participants in cling film, tinfoil and warming blankets. Subsequent cooling was achieved by undressing. Flicker sensitivity (critical flicker fusion frequency) was chosen to assess temporal resolution, while the Freiburg Vision Test was used to determine spatial contrast sensitivity at 1.5 cycles per degree. Scanning laser ophthalmoscopy was used to measure retinal trunk vessel diameters. Assessment was made at baseline, during hyperthermia and after cooling. The induction of a mean increase in core body temperature of 1.02°C was associated with a 7.15-mmHg mean reduction in systolic blood pressure (p < 0.01), a 10.6-mmHg mean reduction in diastolic blood pressure (p < 0.01), a mean increase in pulse rate of 36.3 bpm (p < 0.0001), a 2.66% improvement in flicker sensitivity (CI95 1.37-3.94, p < 0.001), a 2.80% increase in retinal artery diameters (CI95 1.09-4.51, p < 0.01) and a 2.95% increase in retinal vein diameters (CI95 0.96-4.94, p < 0.01). There was no detectable effect of temperature on spatial contrast sensitivity. All ocular test parameters returned to baseline levels after cooling. Increased core body temperature was accompanied by improved temporal visual resolution and retinal trunk vessel dilation. The results suggest that hyperthermia is associated with enhanced retinal function and increased retinal metabolism. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  20. Cognitive Ability as a Resource for Everyday Functioning among Older Adults Who Are Visually Impaired

    Science.gov (United States)

    Heyl, Vera; Wahl, Hans-Werner

    2010-01-01

    This article reports on a study that investigated the role of cognitive resources in the everyday functioning of 121 older adults who were visually impaired and 150 sighted older adults, with a mean age of 82 years. Cognitive performance and everyday functioning were most strongly related in the group who were visually impaired. The authors…

  1. The Effects of Anticholinesterases and Atropine Derivatives on Visual Function in Human Subjects

    Science.gov (United States)

    1988-02-01

    frequency was also measured as the mean of 3 readings obtained with the Visual Function Tester of Genco and Task (1984), which was on loan from the US Air...and physostigmine eyedrops. Experimental Eye Research 20, 15-21. Genco ,L.V. and Task, H.L. (1984). Testing changes in visual function due to orbital

  2. Executive Function and Behavioral Problems in Students with Visual Impairments at Mainstream and Special Schools

    Science.gov (United States)

    Heyl, Vera; Hintermair, Manfred

    2015-01-01

    Introduction: In this study, executive function of school-aged children with visual impairments (that is, those who are blind or have low vision) is examined in the context of behavioral problems and communicative competence. Methods: Teachers assessed the executive function of a sample of 226 visually impaired students from mainstream schools and…

  3. Neural Correlates of Visual Perceptual Expertise: Evidence from Cognitive Neuroscience Using Functional Neuroimaging

    Science.gov (United States)

    Gegenfurtner, Andreas; Kok, Ellen M.; van Geel, Koos; de Bruin, Anique B. H.; Sorger, Bettina

    2017-01-01

    Functional neuroimaging is a useful approach to study the neural correlates of visual perceptual expertise. The purpose of this paper is to review the functional-neuroimaging methods that have been implemented in previous research in this context. First, we will discuss research questions typically addressed in visual expertise research. Second,…

  4. Functional and structural connectivity of the visual system in infants with perinatal brain injury.

    Science.gov (United States)

    Merhar, Stephanie L; Gozdas, Elveda; Tkach, Jean A; Harpster, Karen L; Schwartz, Terry L; Yuan, Weihong; Kline-Fath, Beth M; Leach, James L; Altaye, Mekibib; Holland, Scott K

    2016-07-01

    Infants with perinatal brain injury are at risk of later visual problems. Advanced neuroimaging techniques show promise to detect functional and structural alterations of the visual system. We hypothesized that infants with perinatal brain injury would have less brain activation during a visual functional magnetic resonance imaging (fMRI) task and reduced task-based functional connectivity and structural connectivity as compared with healthy controls. Ten infants with perinatal brain injury and 20 control infants underwent visual fMRI and diffusion tensor imaging (DTI) during natural sleep with no sedation. Activation maps, functional connectivity maps, and structural connectivity were analyzed and compared between the two groups. Most infants in both groups had negative activation in the visual cortex during the fMRI task. Infants with brain injury showed reduced activation in the occipital cortex, weaker connectivity between visual areas and other areas of the brain during the visual task, and reduced fractional anisotropy in white matter tracts projecting to visual regions, as compared with control infants. Infants with brain injury sustained in the perinatal period showed evidence of decreased brain activity and functional connectivity during a visual task and altered structural connectivity as compared with healthy term neonates.

  5. Visual outcome, endocrine function and tumor control after fractionated stereotactic radiation therapy of craniopharyngiomas in adults

    DEFF Research Database (Denmark)

    Astradsson, Arnar; Munck Af Rosenschöld, Per; Feldt-Rasmussen, Ulla

    2017-01-01

    BACKGROUND: The purpose of this study was to examine visual outcome, endocrine function and tumor control in a prospective cohort of craniopharyngioma patients, treated with fractionated stereotactic radiation therapy (FSRT). MATERIAL AND METHODS: Sixteen adult patients with craniopharyngiomas were.......7-13.1) for visual outcome, endocrine function, and tumor control, respectively. RESULTS: Visual acuity impairment was present in 10 patients (62.5%) and visual field defects were present in 12 patients (75%) before FSRT. One patient developed radiation-induced optic neuropathy at seven years after FSRT. Thirteen...

  6. The visual corticostriatal loop through the tail of the caudate: Circuitry and function

    Directory of Open Access Journals (Sweden)

    Carol A Seger

    2013-12-01

    Full Text Available Although high level visual cortex projects to a specific region of the striatum, the tail of the caudate, and participates in corticostriatal loops, the function of this visual corticostriatal system is not well understood. This article first reviews what is known about the anatomy of the visual corticostriatal loop across mammals, including rodents, cats, monkeys, and humans. Like other corticostriatal systems, the visual corticostriatal system includes both closed loop components (recurrent projections that return to the originating cortical location and open loop components (projections that terminate in other neural regions. The article then reviews what previous empircal research has shown about the function of the tail of the caudate. The article finally addresses the possible functions of the closed and open loop connections of the visual loop in the context of theories and computational models of corticostriatal function.

  7. Diabetes reduces the cognitive function with the decrease of the visual perception and visual motor integration in male older adults.

    Science.gov (United States)

    Yun, Hyo-Soon; Kim, Eunhwi; Suh, Soon-Rim; Kim, Mi-Han; Kim, Hong

    2013-01-01

    This study investigated the influence of diabetes on cognitive decline between the diabetes and non- diabetes patients and identified the associations between diabetes and cognitive function, visual perception (VP), and visual motor integration (VMI). Sixty elderly men (67.10± 1.65 yr) with and without diabetes (n= 30 in each group) who were surveyed by interview and questionnaire in South Korea were enrolled in this study. The score of Mini-Mental State Examination of Korean version (MMSE-KC), Motor-free Visual Perception Test-Vertical Format (MVPT-V), and Visual-Motor Integration 3rd Revision (VMI-3R) were assessed in all of the participants to evaluate cognitive function, VP, and VMI in each. The score of MMSE-KC in the diabetic group was significantly lower than that of the non-diabetes group (PVMI-3R scores than those in the non-diabetes group (PVMI. In conclusion, we propose that VP and VMI will be helpful to monitor the change of cognitive function in older adults with diabetes as part of the routine management of diabetes-induced cognitive declines.

  8. 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 .... 4 – Sensory adaptation (six questions dealing with light/dark adaptation, visual search, color discrimination, and glare disability) (questions 7a, 7b, ...

  9. Clinical Assessment of Functional Movement in Adults with Visual Impairments

    Science.gov (United States)

    Ray, Christopher T.; Horvat, Michael; Williams, Michael; Blasch, Bruce B.

    2007-01-01

    Adults with visual impairments have significantly more health risks than do sighted adults because of a number of factors, including the lower mineral density of their femoral neck bones, which is indicative of reduced weight-bearing exercise; their lesser maximal strength; and their higher rates of stroke, osteoporosis, depression, hypertension,…

  10. Visual Afterimages of Emotional Faces in High Functioning Autism

    Science.gov (United States)

    Rutherford, M. D.; Troubridge, Erin K.; Walsh, Jennifer

    2012-01-01

    Fixating an emotional facial expression can create afterimages, such that subsequent faces are seen as having the opposite expression of that fixated. Visual afterimages have been used to map the relationships among emotion categories, and this method was used here to compare ASD and matched control participants. Participants adapted to a facial…

  11. Assessing the functions and dimensions of visualizations in foresight

    DEFF Research Database (Denmark)

    Müller, Adrian W.; Schwarz, Jan Oliver

    -researchers, designers and innovation strategist, was to assess how visualization of foresight results can be applied, reflecting on different purposes and context. The study based insights are then applied to a comprehensive foresight project case in context of electromobility in Switzerland....

  12. Comparison of the visual function index to the Snellen Visual Acuity Test in predicting older adult self-restricted driving.

    Science.gov (United States)

    Lotfipour, Shahram; Patel, Bhakti Harishchandra; Grotsky, Thomas Aaron; Anderson, Craig L; Carr, Erin M; Ahmed, Suleman Syed; Chakravarthy, Bharath; Fox, John Christian; Vaca, Federico E

    2010-10-01

    In this observational study, a modified version of the Visual Function Index (VF-14) and the Snellen Visual Acuity Test were compared in how well they correlated with self-restricted driving habits in older adults. The VF-14 was originally designed to assess vision in cataract patients; however, in this study, a modified version (mVF-14) was evaluated as a tool for predicting self-restricted driving in older drivers. During a 3-month period, 151 drivers over the age of 65 were screened at the local senior center. In addition to the Snellen Visual Acuity Test and mVF-14, each participant was given a questionnaire about their driving habits, previously used in self-restriction studies. Out of 151 total participants, 134 were included and 7 nondrivers and 10 subjects who did not complete all questionnaires were excluded. One hundred one participants exhibited normal visual acuity of 20/40 or better (75%), and 110 scored over 90 on the mVF-14 (82%). Spearman's rank sum correlation coefficient was used to analyze the data and showed significant negative correlation of the mVF-14 and Snellen with self-restricted driving. Individuals with normal vision (20/40 or better on the Snellen eye test) had both high and low mVF-14 scores. The study shows that poor vision, as indicated by the Snellen scale and low mVF-14 scores, correlates to self-imposed driving limitations. The mVF-14 showed further distinctions of self-restriction between individuals in the same Snellen Visual Acuity category. Therefore, using the mVF-14 in addition to the Snellen Visual Acuity Test can be helpful to further differentiate visual ability within older drivers who appear to have normal vision.

  13. Shape Preserving Positive and Convex Data Visualization using Rational Bi-cubic Functions

    Directory of Open Access Journals (Sweden)

    Tahira Sumbal Shaikh

    2012-01-01

    Full Text Available This paper is concerned with the problem of positive and convex data visualization in the form of positive and convex surfaces. A rational bi-cubic partially blended function with eight free parameters in its description is introduced and applied to visualize the shape of positive data and convex data. The developed schemes in this paper have unique representations. Visual models of surfaces attain  smoothness.  

  14. Impaired functional differentiation for categories of objects in the ventral visual stream: A case of developmental visual impairment.

    Science.gov (United States)

    Martinaud, Olivier; Pouliquen, Dorothée; Parain, Dominique; Goldenberg, Alice; Gérardin, Emmanuel; Hannequin, Didier; Altarelli, Irène; Ramus, Franck; Hertz-Pannier, Lucie; Dehaene-Lambertz, Ghislaine; Cohen, Laurent

    2015-10-01

    We report the case of a 14-year-old girl suffering from severe developmental visual impairment along with delayed language and cognitive development, and featuring a clear-cut dissociation between spared dorsal and impaired ventral visual pathways. Visual recognition of objects, including faces and printed words, was affected. In contrast, movement perception and visually guided motor control were preserved. Structural MRI was normal on inspection, but Voxel Based Morphometry (VBM) revealed reduced grey matter density in the mesial occipital and ventral occipito-temporal cortex. Functional MRI during the perception of line drawings uncovered impaired differentiation which is normally observed at even younger ages: no local category preferences could be identified within the occipito-temporal cortex for faces, houses, words or tools. In contrast, movement-related activations appeared to be normal. Finally, those abnormalities evolved on the background of chronic bilateral occipital epileptic activity, including continuous spike-wave discharges during sleep, which may be considered as the primary cause of non-specific intellectual disability and visual impairment.

  15. 3D functional ultrasound imaging of the cerebral visual system in rodents.

    Science.gov (United States)

    Gesnik, Marc; Blaize, Kevin; Deffieux, Thomas; Gennisson, Jean-Luc; Sahel, José-Alain; Fink, Mathias; Picaud, Serge; Tanter, Mickaël

    2017-02-03

    3D functional imaging of the whole brain activity during visual task is a challenging task in rodents due to the complex tri-dimensional shape of involved brain regions and the fine spatial and temporal resolutions required to reveal the visual tract. By coupling functional ultrasound (fUS) imaging with a translational motorized stage and an episodic visual stimulation device, we managed to accurately map and to recover the activity of the visual cortices, the Superior Colliculus (SC) and the Lateral Geniculate Nuclei (LGN) in 3D. Cerebral Blood Volume (CBV) responses during visual stimuli were found to be highly correlated with the visual stimulus time profile in visual cortices (r=0.6), SC (r=0.7) and LGN (r=0.7). These responses were found dependent on flickering frequency and contrast, and optimal stimulus parameters for largest CBV increases were obtained. In particular, increasing the flickering frequency higher than 7Hz revealed a decrease of visual cortices response while the SC response was preserved. Finally, cross-correlation between CBV signals exhibited significant delays (d=0.35s +/-0.1s) between blood volume response in SC and visual cortices in response to our visual stimulus. These results emphasize the interest of fUS imaging as a whole brain neuroimaging modality for brain vision studies in rodent models.

  16. Structural-functional relationships between eye orbital imaging biomarkers and clinical visual assessments

    Science.gov (United States)

    Yao, Xiuya; Chaganti, Shikha; Nabar, Kunal P.; Nelson, Katrina; Plassard, Andrew; Harrigan, Rob L.; Mawn, Louise A.; Landman, Bennett A.

    2017-02-01

    Eye diseases and visual impairment affect millions of Americans and induce billions of dollars in annual economic burdens. Expounding upon existing knowledge of eye diseases could lead to improved treatment and disease prevention. This research investigated the relationship between structural metrics of the eye orbit and visual function measurements in a cohort of 470 patients from a retrospective study of ophthalmology records for patients (with thyroid eye disease, orbital inflammation, optic nerve edema, glaucoma, intrinsic optic nerve disease), clinical imaging, and visual function assessments. Orbital magnetic resonance imaging (MRI) and computed tomography (CT) images were retrieved and labeled in 3D using multi-atlas label fusion. Based on the 3D structures, both traditional radiology measures (e.g., Barrett index, volumetric crowding index, optic nerve length) and novel volumetric metrics were computed. Using stepwise regression, the associations between structural metrics and visual field scores (visual acuity, functional acuity, visual field, functional field, and functional vision) were assessed. Across all models, the explained variance was reasonable (R2 0.1-0.2) but highly significant (p < 0.001). Instead of analyzing a specific pathology, this study aimed to analyze data across a variety of pathologies. This approach yielded a general model for the connection between orbital structural imaging biomarkers and visual function.

  17. Visual and Artistic Functions of Letters Khaghani’s Poetry

    Directory of Open Access Journals (Sweden)

    Dr. M. Zolfaghari

    smallest part of speech, but it is a starting point for the imagination of the poet, to the extent that looked sharp and sensitive poet sees the world in every letter. Accordingly, some of the functions and aspects of artistic creations and authentic style to the characters in Khaghani poetry recently have been studied. Aspects of auditory, visual aspect (type a specific word or a letter appearance and its resemblance to other things such as the shape of the teeth and mouth shaped letter “s” or a spear or arrow, the semantic aspect of the letters, numeric characters, side effects of the text of Quran sectional, the aesthetic aspect of the characters (respecting figures of speech, syllable, allegory, ambiguity, metaphor, etc. In general it can be said that the letters have a lot of potential characters in poetry and Khaghani as a creative poet and adolescent well be aware of the power of words and he could used the power in the artistic context of his poetry art

  18. Experimental study on the effects of visualized functionally abstracted information on process control tasks

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Dong-Han [School of Computing Science, Middlesex University, The Burroughs London, London NW4 4BT (United Kingdom)], E-mail: d.ham@mdx.ac.uk; Yoon, Wan Chul [Department of Industrial Engineering, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Taejon 305-701 (Korea, Republic of); Han, Byoung-Tae [Global Consumer Group, Citibank Korea Inc., Shinmoon-ro, Chongro-gu, Seoul 110-762 (Korea, Republic of)

    2008-02-15

    Two distinct design problems of information display for process control are information content representation and visual form design. Regarding information content, we experimentally showed the effectiveness of functionally abstracted information without the benefits of sophisticated graphical presentation in various task situations. However, since it is obvious that the effects of the information display are also influenced by display formats (i.e., visual forms) as well as the information content, further research was required to investigate the effectiveness of visualized functionally abstracted information. For this purpose, this study conducted an experiment in complex process control tasks (operation and fault diagnosis). The experimental purposes were to confirm the effectiveness of the functionally abstracted information visualized with emergent features or peculiar geometric forms and to examine the additional effects of the visualization on task performance. The results showed that functionally abstracted information presented with sophisticated visual forms helped operators perform process control tasks in more efficient and safe way. The results also indicated the importance of explicit visualization of goal-means relation between higher and lower abstraction levels. Lastly, this study proposed a framework for designing visual forms for process control display.

  19. Visual orientation in hospitalized boys with early onset conduct disorder and borderline intellectual functioning

    NARCIS (Netherlands)

    van der Meere, Jacob; Börger, Norbert; Pirila, Silja

    2012-01-01

    The aim of the present study is to investigate visual orientation in hospitalized boys with severe early onset conduct disorder and borderline intellectual functioning. It is tested whether boys with the dual diagnosis have a stronger action-oriented response style to visual-cued go signals than the

  20. Visual orientation in hospitalized boys with early onset conduct disorder and borderline intellectual functioning

    NARCIS (Netherlands)

    van der Meere, Jacob; Börger, Norbert; Pirila, Silja

    2012-01-01

    The aim of the present study is to investigate visual orientation in hospitalized boys with severe early onset conduct disorder and borderline intellectual functioning. It is tested whether boys with the dual diagnosis have a stronger action-oriented response style to visual-cued go signals than the

  1. 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)

  2. Impact of retinopathy of prematurity on ocular structures and visual functions.

    Science.gov (United States)

    Fielder, Alistair; Blencowe, Hannah; O'Connor, Anna; Gilbert, Clare

    2015-03-01

    The preterm baby may develop ophthalmic sequelae which can be due to prematurity per se, due to retinopathy of prematurity (ROP) or due to neurological damage. Focusing on the former two, we discuss how in high-income countries the risk of sight-threatening ROP is largely confined to babies visual impairment. We discuss sequelae and how they affect the eye and its shape, strabismus and finally consider their impact on visual functions, including visual acuity, the visual field, colour vision and contrast sensitivity.

  3. STS-44 Pilot Henricks uses Visual Function Tester (VFT) on OV-104's middeck

    Science.gov (United States)

    1991-01-01

    STS-44 Pilot Terence T. Henricks tests his visual acuity with the Visual Function Tester 1 (VFT-1) on the middeck of Atlantis, Orbiter Vehicle (OV) 104. VFT-1 measures changes in the vision of an astronaut in microgravity. It is a hand-held, battery-powered device with a binocular eyepiece that uses controlled illumination to present a variety of visual targets for testing primarily visual acuity and eye interaction effects, such as stereopsis and eye dominance. This experiment is being conducted in conjunction with the Military Man in Space activities.

  4. Increased functional connectivity between language and visually deprived areas in late and partial blindness.

    Science.gov (United States)

    Sabbah, Norman; Authié, Colas N; Sanda, Nicolae; Mohand-Saïd, Saddek; Sahel, José-Alain; Safran, Avinoam B; Habas, Christophe; Amedi, Amir

    2016-08-01

    In the congenitally blind, language processing involves visual areas. In the case of normal visual development however, it remains unclear whether later visual loss induces interactions between the language and visual areas. This study compared the resting-state functional connectivity (FC) of retinotopic and language areas in two unique groups of late visually deprived subjects: (1) blind individuals suffering from retinitis pigmentosa (RP), (2) RP subjects without a visual periphery but with preserved central "tunnel vision", both of whom were contrasted with sighted controls. The results showed increased FC between Broca's area and the visually deprived areas in the peripheral V1 for individuals with tunnel vision, and both the peripheral and central V1 for blind individuals. These findings suggest that FC can develop in the adult brain between the visual and language systems in the completely and partially blind. These changes start in the deprived areas and increase in size (involving both foveal and peripheral V1) and strength (from negative to positive FC) as the disease and sensory deprivation progress. These observations support the claim that functional connectivity between remote systems that perform completely different tasks can change in the adult brain in cases of total and even partial visual deprivation.

  5. Leading effect of visual plant characteristics for functional uses of green spaces

    Directory of Open Access Journals (Sweden)

    Beyza Şat Güngör

    2016-07-01

    Full Text Available Plant materials have the ability to lead the people’s functional use purposes with their visual characteristics. In this study, we examined whether the functional use follows the plant materials’ visual characteristics like a big size tree’s shade use. As visual characteristics of the plants; size, texture, color, and planting design basics are considered. Six urban green spaces determined for this experimental field study in the center of Kırklareli Province, and then a site survey implemented to determine apparent visual characteristics of the plants and matched functional uses with their visual characteristics. Five functional use types determined according to the visual plant characteristics (sitting and resting, pedestrian transition, meeting point, walking and recreational uses. Best representing four photos of each green space’s plant materials are used in photo questionnaires. 89 photo questionnaires were conducted. Five functional use type options indicated in the questionnaire for each green space and one of the options were coinciding with the visual plant characteristics of that green space according to the site survey results. For the analyses of questionnaires; SPSS 17 statistical packages were used. As result; the hypothesis was confirmed by coinciding statistical analyses results with the site survey results.

  6. Visual functions of commercial drivers in relation to road accidents in Nigeria.

    Science.gov (United States)

    Oladehinde, M K; Adeoye, A O; Adegbehingbe, B O; Onakoya, A O

    2007-05-01

    To determine the effects of the visual functions on the occurrence of road traffic accidents (RTA) amongst commercial drivers in Ife central local government area (LGA) of Osun state of Nigeria. A cross-sectional study. Four major motor parks located at Ife Central LGA. Of the estimated 270 commercial drivers in the four major parks of the LGA, 215 consecutive drivers were interviewed and had their eyes examined. Structured questionnaires were administered by an ophthalmologist. The prevalence of visual impairment (visual acuity stereopsis and color vision impairment did not have any significant association with RTA. Poor visual acuity is strongly associated with RTA amongst Nigerian commercial drivers as opposed to visual field defect, abnormal color vision and stereopsis. A significant proportion of visual impairment was due to uncorrected refractive errors.

  7. Basic visual function and cortical thickness patterns in posterior cortical atrophy.

    Science.gov (United States)

    Lehmann, Manja; Barnes, Josephine; Ridgway, Gerard R; Wattam-Bell, John; Warrington, Elizabeth K; Fox, Nick C; Crutch, Sebastian J

    2011-09-01

    Posterior cortical atrophy (PCA) is characterized by a progressive decline in higher-visual object and space processing, but the extent to which these deficits are underpinned by basic visual impairments is unknown. This study aimed to assess basic and higher-order visual deficits in 21 PCA patients. Basic visual skills including form detection and discrimination, color discrimination, motion coherence, and point localization were measured, and associations and dissociations between specific basic visual functions and measures of higher-order object and space perception were identified. All participants showed impairment in at least one aspect of basic visual processing. However, a number of dissociations between basic visual skills indicated a heterogeneous pattern of visual impairment among the PCA patients. Furthermore, basic visual impairments were associated with particular higher-order object and space perception deficits, but not with nonvisual parietal tasks, suggesting the specific involvement of visual networks in PCA. Cortical thickness analysis revealed trends toward lower cortical thickness in occipitotemporal (ventral) and occipitoparietal (dorsal) regions in patients with visuoperceptual and visuospatial deficits, respectively. However, there was also a lot of overlap in their patterns of cortical thinning. These findings suggest that different presentations of PCA represent points in a continuum of phenotypical variation.

  8. A Genetic Model for Understanding Higher Order Visual Processing: Functional Interactions of the Ventral Visual Stream in Williams Syndrome

    Science.gov (United States)

    Sarpal, Deepak; Buchsbaum, Bradley R.; Kohn, Philip D.; Kippenhan, J. Shane; Mervis, Carolyn B.; Morris, Colleen A.; Meyer-Lindenberg, Andreas

    2008-01-01

    Williams syndrome (WS) is a rare neurodevelopmental disorder caused by a 1.6 Mb microdeletion on chromosome 7q11.23 and characterized by hypersocial personality and prominent visuospatial construction impairments. Previous WS studies have identified functional and structural abnormalities in the hippocampal formation, prefrontal regions crucial for amygdala regulation and social cognition, and the dorsal visual stream, notably the intraparietal sulcus (IPS). Although aberrant ventral stream activation has not been found in WS, object-related visual information that is processed in the ventral stream is a critical source of input into these abnormal regions. The present study, therefore, examined neural interactions of ventral stream areas in WS. Using a passive face- and house-viewing paradigm, activation and functional connectivity of stimulus-selective regions in fusiform and parahippocampal gyri, respectively, were investigated. During house viewing, significant activation differences were observed between participants with WS and a matched control group in IPS. Abnormal functional connectivity was found between parahippocampal gyrus and parietal cortex and between fusiform gyrus and a network of brain regions including amygdala and portions of prefrontal cortex. These results indicate that abnormal upstream visual object processing may contribute to the complex cognitive/behavioral phenotype in WS and provide a systems-level characterization of genetically mediated abnormalities of neural interactions. PMID:18308711

  9. Visual-motor and executive functions in children born preterm: the Bender Visual Motor Gestalt Test revisited.

    Science.gov (United States)

    Böhm, Birgitta; Lundequist, Aiko; Smedler, Ann-Charlotte

    2010-10-01

    Visual-motor development and executive functions were investigated with the Bender Test at age 5½ years in 175 children born preterm and 125 full-term controls, within the longitudinal Stockholm Neonatal Project. Assessment also included WPPSI-R and NEPSY neuropsychological battery for ages 4-7 (Korkman, 1990). Bender protocols were scored according to Brannigan & Decker (2003), Koppitz (1963) and a complementary neuropsychological scoring system (ABC), aimed at executive functions and developed for this study. Bender results by all three scoring systems were strongly related to overall cognitive level (Performance IQ), in both groups. The preterm group displayed inferior visual-motor skills compared to controls also when controlling for IQ. The largest group differences were found on the ABC scoring, which shared unique variance with NEPSY tests of executive function. Multiple regression analyses showed that hyperactive behavior and inattention increased the risk for visual-motor deficits in children born preterm, whereas no added risk was seen among hyperactive term children. Gender differences favoring girls were strongest within the preterm group, presumably reflecting the specific vulnerability of preterm boys. The results indicate that preterm children develop a different neurobehavioral organization from children born at term, and that the Bender test with a neuropsychological scoring is a useful tool in developmental screening around school start.

  10. Reduction of Interhemispheric Functional Connectivity in Sensorimotor and Visual Information Processing Pathways in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Xu Lang

    2016-01-01

    Conclusions: Interhemispheric functional connectivity in the sensorimotor and visual processing pathways was reduced in patients with schizophrenia, but this reduction was unrelated to the disease state; thus, this reduction may serve as a trait marker of schizophrenia.

  11. Recovery of Visual Function after Administration of Dabigatran Etexilate

    Directory of Open Access Journals (Sweden)

    Carl-Ludwig Schönfeld

    2014-08-01

    Full Text Available A 46-year-old Caucasian female underwent pars plana vitrectomy (ppv for retinal detachment. After the procedure, the patient could only distinguish hand movements; the condition was tentatively diagnosed as nonarteritic anterior ischemic optic neuropathy. Conventional treatment with systemic corticosteroids and acetylsalicylic acid was ineffective and yielded substantial steroid-related side effects. Additional administration of 2 × 110 mg dabigatran etexilate (Pradaxa®, a novel direct thrombin inhibitor, resulted in a prompt and marked improvement of visual acuity, which indicated improved blood flow in the central vessels of the optic nerve. Dabigatran etexilate may provide a promising alternative for the treatment of postprocedural vision loss after ppv.

  12. 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.

  13. The PedsQL™ Present Functioning Visual Analogue Scales: preliminary reliability and validity

    OpenAIRE

    Varni James W; Burwinkle Tasha M; Eisen Sarajane; Sherman Sandra A

    2006-01-01

    Abstract Background The PedsQL™ Present Functioning Visual Analogue Scales (PedsQL™ VAS) were designed as an ecological momentary assessment (EMA) instrument to rapidly measure present or at-the-moment functioning in children and adolescents. The PedsQL™ VAS assess child self-report and parent-proxy report of anxiety, sadness, anger, worry, fatigue, and pain utilizing six developmentally appropriate visual analogue scales based on the well-established Varni/Thompson Pediatric Pain Questionnai...

  14. Semiautomatic transfer function initialization for abdominal visualization using self-generating hierarchical radial basis function networks.

    Science.gov (United States)

    Selver, M Alper; Güzeliş, Cüneyt

    2009-01-01

    As being a tool that assigns optical parameters used in interactive visualization, Transfer Functions (TF) have important effects on the quality of volume rendered medical images. Unfortunately, finding accurate TFs is a tedious and time consuming task because of the trade off between using extensive search spaces and fulfilling the physician's expectations with interactive data exploration tools and interfaces. By addressing this problem, we introduce a semi-automatic method for initial generation of TFs. The proposed method uses a Self Generating Hierarchical Radial Basis Function Network to determine the lobes of a Volume Histogram Stack (VHS) which is introduced as a new domain by aligning the histograms of slices of a image series. The new self generating hierarchical design strategy allows the recognition of suppressed lobes corresponding to suppressed tissues and representation of the overlapping regions which are parts of the lobes but can not be represented by the Gaussian bases in VHS. Moreover, approximation with a minimum set of basis functions provides the possibility of selecting and adjusting suitable units to optimize the TF. Applications on different CT and MR data sets show enhanced rendering quality and reduced optimization time in abdominal studies.

  15. Zernike vs. Bessel circular functions in visual optics.

    Science.gov (United States)

    Trevino, Juan P; Gómez-Correa, Jesus E; Iskander, D Robert; Chávez-Cerda, Sabino

    2013-07-01

    We propose the Bessel Circular Functions as alternatives of the Zernike Circle Polynomials to represent relevant circular ophthalmic surfaces. We assess the fitting capabilities of the orthogonal Bessel Circular Functions by comparing them to Zernike Circle Polynomials for approximating a variety of computationally generated surfaces which can represent ophthalmic surfaces. The Bessel Circular Functions showed better modelling capabilities for surfaces with abrupt variations such as the anterior eye surface at the limbus region, and influence functions. From our studies we find that the Bessel Circular Functions can be more suitable for studying particular features of post surgical corneal surfaces. We show that given their boundary conditions and free oscillating properties, the Bessel Circular Functions are an alternative for representing specific wavefronts and can be better than the Zernike Circle Polynomials for some important cases of corneal surfaces, influence functions and the complete anterior corneal surface. © 2013 The Authors Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

  16. Visual function of police officers who have undergone refractive surgery.

    Science.gov (United States)

    Hovis, Jeffery K; Ramaswamy, Shankaran

    2006-11-01

    The visual acuity and contrast sensitivity of police recruits and officers was evaluated in both normal and dim illumination conditions to determine whether officers who have had refractive surgery have compromised night vision. The control group consisted of 76 officers and recruits who have not had refractive surgery and the refractive surgery group consisted of 22 officers and recruits who had refractive surgery. Visual acuity and contrast sensitivity were measured under both room illumination and dim illumination. The room illumination test series included high contrast acuity, low contrast acuity and Pelli-Robson contrast sensitivity. The dim illumination test series included high contrast acuity, low contrast acuity, Pelli-Robson contrast sensitivity, license plate number acuity (with and without glare) and the Mesotest. The general findings were that the refractive surgery group had lower acuity scores on low contrast targets in both room and dim light levels along with a reduction in the Mesotest scores with a glare source compared to the control group. Although refractive surgery police recruits and officers had reduced performance on some vision tests, these reductions were small and it is unlikely that their performance on vision related tasks would be compromised, on average. The major concern is the small number of refractive surgery candidates whose results were well outside the range of the non-surgical candidates. Their vision may be unacceptable for policing. Copyright (c) 2006 Wiley-Liss, Inc.

  17. Dynamics of functional state of sensory visual system of technical specialties students during educational day

    Directory of Open Access Journals (Sweden)

    Rovniy A.S.

    2010-09-01

    Full Text Available The problem of adaptation of students of freshmen is examined to the educational loadings during educational day. In research took part 93 students in the age of 17-18. It is set that the visual sensory system is the indicator of reacting of organism on the different types of fatigue - psychical, mental, physical. It is rotined that playing table tennis is a substantial mean in renewal of functions of the visual sensory system. It is marked that the natural increase of adaptation to the educational loadings reduces the level of functional changes of the visual sensory system.

  18. Child behavior check list and Korean personality inventory for children with functional visual loss.

    Science.gov (United States)

    Kyung, Sung Eun; Lee, Sang Mi; Lim, Myung Ho

    2014-08-01

    To investigate the clinical psychiatric characteristics of children with the main complaint of functional visual loss, their behavior and personality were evaluated by the means of the Korean child behavior check list (K-CBCL), and the Korean personality inventory for children (KPI-C). The evaluation was carried out by the K-CBCL and the KPI-C, the domestically standardized tools, with 20 child subjects suspected of functional visual loss, among the patients who visited our hospital, between August, 2005 and December, 2012. The control group included 160 children in general schools of the same region. The 20 patients whose main complaint was functional visual loss were diagnosed as having a functional visual disorder. The child patient group showed a higher score for the K-CBCL and KPI-C sub-scales of somatic complaints, social problems, aggressive behavior, internalizing problems, externalizing problems, total behavioral problems, somatization and hyperactivity, than that of the control group. The results of the K-CBCL and KPI-C tests among children with functional visual loss, were significantly different from those of the normal control group. This result suggested that psychological factors may influence children with a main complaint of functional visual loss.

  19. Visual function of Egyptian children with low vision and the demographic determinants

    Directory of Open Access Journals (Sweden)

    El Byoumi Boshra

    2010-01-01

    Full Text Available Aims: To determine whether the LV Prasad-Functional Vision Questionnaire (LVP-FVQ could be used to assess self-reported visual function and quality of visual life in Egyptian school aged children. Materials and Methods: The LVP-FVQ was used to assess the quality of visual function in school-age children. All subjects were students at the time of assessment. Subjects underwent a visual function assessment that included distance and near visual acuity, contrast sensitivity, color vision and visual field examination where possible. Data analysis were for both descriptive and inference statistics. A P < 0.05 was considered statistically significant. Results: Fifty children aged 11.28 ± 3.5 years (range, 5 years to 18 years with moderate-to-severe visual impairment most of their lives were enrolled. Twenty-two subjects (44% had albinism, 18 (36% subjects had hereditary retinal dystrophy, 6 (12% subjects had cone dystrophy, 2 (4% subjects had bilateral amblyopia and 2 (4% subjects had congenital coloboma without other disabilities. The four most difficult tasks were related to the following daily activities alluded to in the questionnaire such as reading a textbook at arms length, copying from the blackboard, seeing somebody across the road and identifying colors. There was no statistically significant association between the demographic variables and the level of visual functioning, sex, age, type of school, family history or consanguinity (P > 0.05 for all variables. Conclusion: LVP-FVQ can be used to screen Egyptian children with visual impairment. Input and integration of the parents and the school teachers to evaluate the child s behavior at home and the school is essential to developing a balanced questionnaire.

  20. Functional visual acuity in patients with successfully treated amblyopia: a pilot study.

    Science.gov (United States)

    Hoshi, Sujin; Hiraoka, Takahiro; Kotsuka, Junko; Sato, Yumiko; Izumida, Shinya; Kato, Atsuko; Ueno, Yuta; Fukuda, Shinichi; Oshika, Tetsuro

    2017-06-01

    The aim of this study was to use conventional visual acuity measurements to quantify the functional visual acuity (FVA) in eyes with successfully treated amblyopia, and to compare the findings with those for contralateral normal eyes. Nineteen patients (7 boys, 12 girls; age 7.5 ± 2.2 years) with successfully treated unilateral amblyopia and the same conventional decimal visual acuity in both eyes (better than 1.0) were enrolled. FVA, the visual maintenance ratio (VMR), maximum and minimum visual acuity, and the average response time were recorded for both eyes of all patients using an FVA measurement system. The differences in FVA values between eyes were analyzed. The mean LogMAR FVA scores, VMR (p amblyopia than for the contralateral normal eyes. There was no significant difference in the average response time. Our results indicate that FVA and VMR were poorer for eyes with treated amblyopia than for normal eyes, even though the treatment for amblyopia was considered successful on the basis of conventional visual acuity measurements. These results suggest that visual function is impaired in eyes with amblyopia, regardless of treatment success, and that FVA measurements can provide highly valuable diagnosis and treatment information that is not readily provided by conventional visual acuity measurements.

  1. Visual function and color vision in adults with Attention-Deficit/Hyperactivity Disorder.

    Science.gov (United States)

    Kim, Soyeon; Chen, Samantha; Tannock, Rosemary

    2014-01-01

    Color vision and self-reported visual function in everyday life in young adults with Attention-Deficit/Hyperactivity Disorder (ADHD) were investigated. Participants were 30 young adults with ADHD and 30 controls matched for age and gender. They were tested individually and completed the Visual Activities Questionnaire (VAQ), Farnsworth-Munsell 100 Hue Test (FMT) and A Quick Test of Cognitive Speed (AQT). The ADHD group reported significantly more problems in 4 of 8 areas on the VAQ: depth perception, peripheral vision, visual search and visual processing speed. Further analyses of VAQ items revealed that the ADHD group endorsed more visual problems associated with driving than controls. Color perception difficulties on the FMT were restricted to the blue spectrum in the ADHD group. FMT and AQT results revealed slower processing of visual stimuli in the ADHD group. A comprehensive investigation of mechanisms underlying visual function and color vision in adults with ADHD is warranted, along with the potential impact of these visual problems on driving performance. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  2. [An Evaluation of Visual Function in Working Age Patients with Glaucoma].

    Science.gov (United States)

    Murakami, Miki; Obata, Yasuko; Yamato, Hiroshi; Kondo, Hiroyuki

    2015-09-01

    Visual function affects working ability in occupational health. We investigated the frequencies and grades of low vision in working age people who have glaucoma, and studied patients who were receiving low vision care, for example eye movement training. Among 3,905 patients aged 15 to 64 years old who visited Murakami eye clinic from October 2013 to September 2014, there were 363 patients suspected of having glaucoma and 138 patients diagnosed with glaucoma and receiving treatment. We measured their visual acuity and visual field to calculate their functional vision score (FVS). We studied the amount of reduction in visual ability and the number of patients undergoing low vision care by age groups. The vision test and visual field test showed that 18 patients had reduced visual ability, according to the FVS. Their FVS classification was from class 1 (mild vision loss) to class 3a (severe vision loss). The FVS matches the statistics of the WHO and can predict the reading and walking ability in each class. Reduced visual ability was recognized in about 14% of the glaucoma patients older than 45 years of age. 78% of the patients were classified in class 1. In FVS, class 2 (moderate vision loss) or greater is defined as low vision, and class 1 is a condition with no visual reserve. Although such patients have no problems in daily life and office work, they are challenged by on-site work and the on-site environment, and occupational health staff intervention becomes necessary.

  3. Visual function and retinal vessel diameters during hyperthermia in man

    DEFF Research Database (Denmark)

    Jensen, Bettina Hagström; Bram, Thue; Kappelgaard, Per

    2017-01-01

    laser ophthalmoscopy was used to measure retinal trunk vessel diameters. Assessment was made at baseline, during hyperthermia and after cooling. RESULTS: The induction of a mean increase in core body temperature of 1.02°C was associated with a 7.15-mmHg mean reduction in systolic blood pressure (p ... in cling film, tinfoil and warming blankets. Subsequent cooling was achieved by undressing. Flicker sensitivity (critical flicker fusion frequency) was chosen to assess temporal resolution, while the Freiburg Vision Test was used to determine spatial contrast sensitivity at 1.5 cycles per degree. Scanning...... diameters (CI95 0.96-4.94, p cooling. CONCLUSION: Increased core body temperature was accompanied by improved temporal visual resolution and retinal trunk...

  4. NaviGO: interactive tool for visualization and functional similarity and coherence analysis with gene ontology.

    Science.gov (United States)

    Wei, Qing; Khan, Ishita K; Ding, Ziyun; Yerneni, Satwica; Kihara, Daisuke

    2017-03-20

    The number of genomics and proteomics experiments is growing rapidly, producing an ever-increasing amount of data that are awaiting functional interpretation. A number of function prediction algorithms were developed and improved to enable fast and automatic function annotation. With the well-defined structure and manual curation, Gene Ontology (GO) is the most frequently used vocabulary for representing gene functions. To understand relationship and similarity between GO annotations of genes, it is important to have a convenient pipeline that quantifies and visualizes the GO function analyses in a systematic fashion. NaviGO is a web-based tool for interactive visualization, retrieval, and computation of functional similarity and associations of GO terms and genes. Similarity of GO terms and gene functions is quantified with six different scores including protein-protein interaction and context based association scores we have developed in our previous works. Interactive navigation of the GO function space provides intuitive and effective real-time visualization of functional groupings of GO terms and genes as well as statistical analysis of enriched functions. We developed NaviGO, which visualizes and analyses functional similarity and associations of GO terms and genes. The NaviGO webserver is freely available at: http://kiharalab.org/web/navigo .

  5. Structural and functional neuroimaging in patients with Parkinson's disease and visual hallucinations: A critical review.

    Science.gov (United States)

    Lenka, Abhishek; Jhunjhunwala, Ketan Ramakant; Saini, Jitender; Pal, Pramod Kumar

    2015-07-01

    Patients with Parkinson's disease (PD) may develop various non-motor symptoms (NMS) during the course of the illness and psychosis is one of the common NMS of PD. Visual hallucinations (VH) are the most common manifestation of psychosis in PD. The exact pathogenesis of VH in patients with PD is not clearly understood. Presence of VH has been described to be associated with rapid cognitive decline and increased nursing home placements in PD patients. A large number of structural and functional neuroimaging studies have been conducted to understand the cerebral basis of VH in PD. Structural imaging studies (Voxel Based Morphometry) have reported grey matter atrophy in multiple regions of the brain such as primary visual cortex, visual association cortex, limbic regions, cholinergic structures such as pedunculopontine nucleus and substantia innominata, which conclude possible alterations of brain regions associated with functions such as visuospatial-perception, attention control and memory. Most functional neuroimaging studies (functional MRI, positron emission tomography and single photon emission computerized tomography) have reported altered activation, blood flow, or reduced metabolism in both dorsal and ventral visual pathways, which probably indicates an alteration in the normal bottom-top visual processing and the presence of an aberrant top-down visual processing. This review critically analyzes the published studies on the structural and functional neuroimaging in PD patients with VH.

  6. Experiences with Matlab and VRML in Functional Neuroimaging Visualizations

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Hansen, Lars Kai

    2000-01-01

    We describe some experiences with Matlab and VRML. We are developing a toolbox for neuroinformatics and describe some of the functionalities we have implemented or will implement and how Matlab and VRML support the implementation....

  7. Functional magnetic resonance imaging of the normal and abnormal visual system in early life

    DEFF Research Database (Denmark)

    Born, A.P.; Miranda Gimenez-Ricco, Maria Jo; Rostrup, Egill

    2000-01-01

    in very young infants and in infants with brain damage. We examined 15 preterm infants, 12 children suspected of having a cerebral visual impairment and 10 children with a normal visual system, all of whom were either spontaneously asleep or sedated with chloral hydrate. Cortical response to stroboscopic...... showed a signal decrease. The activated cortical volumes showed a linear relation to age for healthy children younger than 90 weeks PMA, but were small in children with visual impairment. In two children with unilateral damage to the optic radiations, activation was strongly asymmetrical with greatest......Functional magnetic resonance imaging (fMRI) in young children may provide information about the development of the visual cortex, and may have predictive value for later visual performance. The purpose of this study was to evaluate the usefulness of fMRI for examining cerebral processing of vision...

  8. Functional magnetic resonance imaging of the normal and abnormal visual system in early life

    DEFF Research Database (Denmark)

    Born, A.P.; Miranda Gimenez-Ricco, Maria Jo; Rostrup, Egill;

    2000-01-01

    in very young infants and in infants with brain damage. We examined 15 preterm infants, 12 children suspected of having a cerebral visual impairment and 10 children with a normal visual system, all of whom were either spontaneously asleep or sedated with chloral hydrate. Cortical response to stroboscopic......Functional magnetic resonance imaging (fMRI) in young children may provide information about the development of the visual cortex, and may have predictive value for later visual performance. The purpose of this study was to evaluate the usefulness of fMRI for examining cerebral processing of vision...... showed a signal decrease. The activated cortical volumes showed a linear relation to age for healthy children younger than 90 weeks PMA, but were small in children with visual impairment. In two children with unilateral damage to the optic radiations, activation was strongly asymmetrical with greatest...

  9. Tactile perception recruits functionally related visual areas in the late-blind.

    Science.gov (United States)

    Goyal, Manu S; Hansen, Peter J; Blakemore, Colin B

    2006-09-18

    When blind people touch Braille characters, blood flow increases in visual areas, leading to speculation that visual circuitry assists tactile discrimination in the blind. We tested this hypothesis in a functional magnetic resonance imaging study designed to reveal activation appropriate to the nature of tactile stimulation. In late-blind individuals, hMT/V5 and fusiform face area activated during visual imagery of moving patterns or faces. When they touched a doll's face, right fusiform face area was again activated. Equally, hMT/V5 was activated when objects moved over the skin. We saw no difference in hMT/V5 or fusiform face area activity during motion or face perception in the congenitally blind. We conclude that specialized visual areas, once established through visual experience, assist equivalent tactile identification tasks years after the onset of blindness.

  10. Current research on the organization and function of the visual system in primates

    Directory of Open Access Journals (Sweden)

    Kaas JH

    2014-09-01

    Full Text Available Jon H Kaas, Pooja Balaram Department of Psychology, Vanderbilt University, Nashville, TN, USAAll primates, including humans, are highly visual creatures.1–3 We rely heavily on visual cues for basic adaptive behaviors such as finding food, mates, and shelter; as well as more complex behaviors such as parental care and the formation of social hierarchies. Throughout the course of primate evolution, our dependence on visual cues has increased with each adaptive advantage acquired from visually guided behavior; and so has the demand for greater and more efficient processing of visual information in primate brains. Consequently, the number, size, and complexity of brain structures involved in visual processing has expanded dramatically in the primate order, far more than those of any other species in the mammalian lineage.2,4 As we have learned to interact with the world using visual cues, our brains have evolved to absorb, manipulate, and react to visual information in increasingly effective ways. Individual brain structures dedicated to vision in primates also frequently exhibit anatomical and functional specializations that are not present in other mammals. These adaptations are not present in most nonprimate mammals, partly because many species rely on other sensory modalities for their individual behaviors. Thus, understanding how we, as humans, perceive the visual world around us begins with learning how vision is processed in the primate brain. Furthermore, learning how vision in primates differs both structurally and functionally from vision in nonprimate mammals, and determining how those changes enable adaptive traits in the primate lineage, will allow us to understand the truly unique phenomenon of human visual behavior.

  11. Changes in Connectivity after Visual Cortical Brain Damage Underlie Altered Visual Function

    Science.gov (United States)

    Bridge, Holly; Thomas, Owen; Jbabdi, Saad; Cowey, Alan

    2008-01-01

    The full extent of the brain's ability to compensate for damage or changed experience is yet to be established. One question particularly important for evaluating and understanding rehabilitation following brain damage is whether recovery involves new and aberrant neural connections or whether any change in function is due to the functional…

  12. Inhibition of the Pim1 oncogene results in diminished visual function.

    Directory of Open Access Journals (Sweden)

    Jun Yin

    Full Text Available Our objective was to profile genetic pathways whose differential expression correlates with maturation of visual function in zebrafish. Bioinformatic analysis of transcriptomic data revealed Jak-Stat signalling as the pathway most enriched in the eye, as visual function develops. Real-time PCR, western blotting, immunohistochemistry and in situ hybridization data confirm that multiple Jak-Stat pathway genes are up-regulated in the zebrafish eye between 3-5 days post-fertilisation, times associated with significant maturation of vision. One of the most up-regulated Jak-Stat genes is the proto-oncogene Pim1 kinase, previously associated with haematological malignancies and cancer. Loss of function experiments using Pim1 morpholinos or Pim1 inhibitors result in significant diminishment of visual behaviour and function. In summary, we have identified that enhanced expression of Jak-Stat pathway genes correlates with maturation of visual function and that the Pim1 oncogene is required for normal visual function.

  13. Visual activation in infants and young children studied by functional magnetic resonance imaging

    DEFF Research Database (Denmark)

    Born, Alfred Peter; Leth, H; Miranda Gimenez-Ricco, Maria Jo

    1998-01-01

    areas of signal decrease during visual stimulation in the occipital cortex (mean decrease 2.21%), contrary to the signal increase observed in the adult controls (mean increase 2.82%). This decrease may be due to a higher proportional increase in oxygen extraction compared with increase in cerebral blood...... it was restricted to the anterior and medial part of the calcarine sulcus in the younger infants. This may reflect a different functional organization of the young child's visual cortex or the on-going retinal development.......The purpose of this study was to determine whether visual stimulation in sleeping infants and young children can be examined by functional magnetic resonance imaging. We studied 17 children, aged 3 d to 48 mo, and three healthy adults. Visual stimulation was performed with 8-Hz flickering light...

  14. The disorganized visual cortex in reelin-deficient mice is functional and allows for enhanced plasticity.

    Science.gov (United States)

    Pielecka-Fortuna, Justyna; Wagener, Robin Jan; Martens, Ann-Kristin; Goetze, Bianka; Schmidt, Karl-Friedrich; Staiger, Jochen F; Löwel, Siegrid

    2015-11-01

    A hallmark of neocortical circuits is the segregation of processing streams into six distinct layers. The importance of this layered organization for cortical processing and plasticity is little understood. We investigated the structure, function and plasticity of primary visual cortex (V1) of adult mice deficient for the glycoprotein reelin and their wild-type littermates. In V1 of rl-/- mice, cells with different laminar fates are present at all cortical depths. Surprisingly, the (vertically) disorganized cortex maintains a precise retinotopic (horizontal) organization. Rl-/- mice have normal basic visual capabilities, but are compromised in more challenging perceptual tasks, such as orientation discrimination. Additionally, rl-/- animals learn and memorize a visual task as well as their wild-type littermates. Interestingly, reelin deficiency enhances visual cortical plasticity: juvenile-like ocular dominance plasticity is preserved into late adulthood. The present data offer an important insight into the capabilities of a disorganized cortical system to maintain basic functional properties.

  15. Development of Experimental Protocol for Visual Cognitive Function Evaluation in Children with Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Pereverzeva D.S.,

    2016-10-01

    Full Text Available The article aims to present experimental protocol for investigation of visual cognitive function in children and adolescents with autism spectrum disorders. Description of experimental design is introduced by theoretical review of visual attention, perception and visual-motor control development in children with idiopathic autism and those with Fragile X mental retardation syndrome. Research method presented in the article is based on recent studies of visual cognitive function development under normal and pathological condition. The protocol includes three experimental paradigms: “antisaccade test”, “big/ figures”, and “photos test” performed by making use of eye tracking recording. This work was supported by grant RFBR 14-06-31284

  16. The Impact of Visual Guided Order Picking on Ocular Comfort, Ocular Surface and Tear Function.

    Directory of Open Access Journals (Sweden)

    Angelika Klein-Theyer

    Full Text Available We investigated the effects of a visual picking system on ocular comfort, the ocular surface and tear function compared to those of a voice guided picking solution.Prospective, observational, cohort study.Institutional.A total of 25 young asymptomatic volunteers performed commissioning over 10 hours on two consecutive days.The operators were guided in the picking process by two different picking solutions, either visually or by voice while their subjective symptoms and ocular surface and tear function parameters were recorded.The visual analogue scale (VAS values, according to subjective dry eye symptoms, in the visual condition were significantly higher at the end of the commissioning than the baseline measurements. In the voice condition, the VAS values remained stable during the commissioning. The tear break-up time (BUT values declined significantly in the visual condition (pre-task: 16.6 sec and post-task: 9.6 sec in the right eyes, that were exposed to the displays, the left eyes in the visual condition showed only a minor decline, whereas the BUT values in the voice condition remained constant (right eyes or even increased (left eyes over the time. No significant differences in the tear meniscus height values before and after the commissioning were observed in either condition.In our study, the use of visually guided picking solutions was correlated with post-task subjective symptoms and tear film instability.

  17. Choosing Your Poison: Optimizing Simulator Visual System Selection as a Function of Operational Tasks

    Science.gov (United States)

    Sweet, Barbara T.; Kaiser, Mary K.

    2013-01-01

    Although current technology simulator visual systems can achieve extremely realistic levels they do not completely replicate the experience of a pilot sitting in the cockpit, looking at the outside world. Some differences in experience are due to visual artifacts, or perceptual features that would not be present in a naturally viewed scene. Others are due to features that are missing from the simulated scene. In this paper, these differences will be defined and discussed. The significance of these differences will be examined as a function of several particular operational tasks. A framework to facilitate the choice of visual system characteristics based on operational task requirements will be proposed.

  18. Heart visualization based on hybrid transfer function using size and gradient.

    Science.gov (United States)

    Xia, Yong; Liu, Yixuan; Wang, Kuanquan

    2014-01-01

    Having the ability to visualize the heart clearly and precisely would be beneficial for pathology research, presurgical planning, and clinical approaches. Multi-dimensional transfer functions were employed to improve the overall performance of images. To provide a satisfactory visualization quality on the shape and boundaries of the heart, a new hybrid transfer function combining structure size with gradient was designed to highlight the area of the heart. Initially, a histogram of gradient and histogram of size was computed and then classification was performed for providing the spatial information. Finally, several hybrid strategies were presented for the design of the transfer function, including opacity and color. By experimental evaluation, the proposed hybrid transfer function visualized the cardiac outline and internal structure more clearly and easily.

  19. Visual impairment, rehabilitation and International Classification of Functioning, Disability and Health

    Directory of Open Access Journals (Sweden)

    Marissa Romano da Silva

    2014-10-01

    Full Text Available Objetive: To describe the characteristics of people with visual impairment who participated in the Visual Rehabilitation Groups, according to the ICD-10 and the International Classification of Functioning, Disability and Health (ICF. Methods: Quantitative, cross-sectional survey, developed in a university rehabilitation research center between october and december 2012. The users from the Visual Rehabilitation Groups were invited; 13 of them agreed to participate. We performed an occupational therapy evaluation – with anamnesis, performance evaluation and functional vision assessment – an analysis of medical charts and patient description with the use of the ICF Results: The major causes of visual impairment were diabetic retinopathy, glaucoma, optical neuritis and keratoconus. Some functions and structures of the body, performance and capabilities in activities and participation, environmental factors facilitators or limiters were highlighted in this study, allowing the description of the characteristics of each participant through the functionality and the improvement of the therapeutic planning. Assistive technologies, optical and non-optical aids used and their everyday benefits were presented. Conclusion: Visual loss, at any level, led to functional impairments, limiting and restricting the participation and performance in everyday activities, interfering with the individuals’ independence, autonomy and quality of life. However, the use of optical aids, non-optical aids and environmental adaptations proved to be beneficial for increasing the functionality, showing the influence of external factors on the performance. Knowing and recognizing the existence of diversities within the visual impairment universe allows us to understand who the treated individual is, avoiding the generalization by the visual condition. The ICF showed to have a fundamental role in this context.

  20. Visualizing Polynomial Functions: New Insights from an Old Method in a New Medium.

    Science.gov (United States)

    Dugdale, Sharon; And Others

    1992-01-01

    Describes and illustrates the Monomial Sums Approach, a graphical learning strategy, facilitated by microcomputer capabilities that allow easy manipulation and exploration of graphical representations of polynomial functions. Reduces emphasis on memorized rules in favor of qualitative understanding of functional behavior, visualization of…

  1. Visualizing the Chain Rule (for Functions over R and C) and More

    Science.gov (United States)

    Kreminski, Rick

    2009-01-01

    A visual approach to understanding the chain rule and related derivative formulae, for functions from R to R and from C to C, is presented. This apparently novel approach has been successfully used with several audiences: students first studying calculus, students with some background in linear algebra, students beginning study of functions of a…

  2. Visualizing the Chain Rule (for Functions over R and C) and More

    Science.gov (United States)

    Kreminski, Rick

    2009-01-01

    A visual approach to understanding the chain rule and related derivative formulae, for functions from R to R and from C to C, is presented. This apparently novel approach has been successfully used with several audiences: students first studying calculus, students with some background in linear algebra, students beginning study of functions of a…

  3. Pigeon visual short-term memory directly compared to primates.

    Science.gov (United States)

    Wright, Anthony A; Elmore, L Caitlin

    2016-02-01

    Three pigeons were trained to remember arrays of 2-6 colored squares and detect which of two squares had changed color to test their visual short-term memory. Procedures (e.g., stimuli, displays, viewing times, delays) were similar to those used to test monkeys and humans. Following extensive training, pigeons performed slightly better than similarly trained monkeys, but both animal species were considerably less accurate than humans with the same array sizes (2, 4 and 6 items). Pigeons and monkeys showed calculated memory capacities of one item or less, whereas humans showed a memory capacity of 2.5 items. Despite the differences in calculated memory capacities, the pigeons' memory results, like those from monkeys and humans, were all well characterized by an inverse power-law function fit to d' values for the five display sizes. This characterization provides a simple, straightforward summary of the fundamental processing of visual short-term memory (how visual short-term memory declines with memory load) that emphasizes species similarities based upon similar functional relationships. By closely matching pigeon testing parameters to those of monkeys and humans, these similar functional relationships suggest similar underlying processes of visual short-term memory in pigeons, monkeys and humans. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. The Effectiveness of a Multidisciplinary Group Rehabilitation Program on the Psychosocial Functioning of Elderly People Who Are Visually Impaired

    NARCIS (Netherlands)

    Alma, Manna A.; Groothoff, Johan W.; Melis-Dankers, Bart J. M.; Suurmeijer, Theodorus; van der Mei, Sijrike F.

    2013-01-01

    Introduction: The pilot study reported here determined the effectiveness of a multidisciplinary group rehabilitation program, Visually Impaired Elderly Persons Participating (VIPP), on psychosocial functioning. Methods: The single-group pretest-posttest pilot study included 29 persons with visual

  5. The Effectiveness of a Multidisciplinary Group Rehabilitation Program on the Psychosocial Functioning of Elderly People Who Are Visually Impaired

    NARCIS (Netherlands)

    Alma, Manna A.; Groothoff, Johan W.; Melis-Dankers, Bart J. M.; Suurmeijer, Theodorus; van der Mei, Sijrike F.

    2013-01-01

    Introduction: The pilot study reported here determined the effectiveness of a multidisciplinary group rehabilitation program, Visually Impaired Elderly Persons Participating (VIPP), on psychosocial functioning. Methods: The single-group pretest-posttest pilot study included 29 persons with visual im

  6. In-vivo imaging of the photoreceptor mosaic in retinal dystrophies and correlations with visual function

    Energy Technology Data Exchange (ETDEWEB)

    Choi, S; Doble, N; Hardy, J; Jones, S; Keltner, J; Olivier, S; Werner, J S

    2005-10-26

    To relate in-vivo microscopic retinal changes to visual function assessed with clinical tests in patients with various forms of retinal dystrophies. The UC Davis Adaptive Optics (AO) Fundus Camera was used to acquire in-vivo retinal images at the cellular level. Visual function tests, consisting of visual field analysis, multifocal electroretinography (mfERG), contrast sensitivity and color vision measures, were performed on all subjects. Five patients with different forms of retinal dystrophies and three control subjects were recruited. Cone densities were quantified for all retinal images. In all images of diseased retinas, there were extensive areas of dark space between groups of photoreceptors, where no cone photoreceptors were evident. These irregular features were not seen in healthy retinas, but were characteristic features in fundi with retinal dystrophies. There was a correlation between functional vision loss and the extent to which the irregularities occurred in retinal images. Cone densities were found to decrease with an associated decrease in retinal function. AO fundus photography is a reliable technique for assessing and quantifying the changes in the photoreceptor layer as disease progresses. Furthermore, this technique can be useful in cases where visual function tests give borderline or ambiguous results, as it allows visualization of individual photoreceptors.

  7. Cerebral basis of visual hallucinations in Parkinson's disease: structural and functional MRI studies.

    Science.gov (United States)

    Ibarretxe-Bilbao, Naroa; Junque, Carme; Marti, Maria J; Tolosa, Eduardo

    2011-11-15

    The presence of visual hallucinations (VH) is a significant predictor of dementia in Parkinson's disease (PD) and it is associated with a more rapid cognitive decline. Non-demented PD patients with VH present greater neuropsychological impairment than those without VH in domains such as verbal and visual memory, language comprehension, and visuospatial and visuoperceptive functions. Frontal dysfunction has also been described in PD with VH, including deficits in verbal fluency, sustained attention, and inhibition. In PD with VH, structural and functional abnormalities within the primary visual system and visual association areas, including ventral and dorsal pathways, have been reported. Structural MRI studies have shown that non-demented PD patients with VH present grey matter reduction in parieto-occipital areas and the hippocampal head. A follow-up study performed at a mean of 30 months revealed that unlike PD patients without VH, PD patients with VH frequently develop dementia associated with progressive atrophy in limbic, paralimbic and neocortical areas. Functional MRI (fMRI) studies have revealed altered activation in occipito-temporal and frontal areas in response to simple and complex visual stimuli in PD patients with VH, suggesting a marked impairment in bottom-up visual processing, as well as an attentional deficit in the pathophysiology of VH in PD.

  8. Gelatin Functionalization of Biomaterial Surfaces: Strategies for Immobilization and Visualization

    Directory of Open Access Journals (Sweden)

    Peter Dubruel

    2011-01-01

    Full Text Available In the present work, the immobilization of gelatin as biopolymer on two types of implantable biomaterials, polyimide and titanium, was compared. Both materials are known for their biocompatibility while lacking cell-interactive behavior. For both materials, a pre-functionalization step was required to enable gelatin immobilization. For the polyimide foils, a reactive succinimidyl ester was introduced first on the surface, followed by covalent grafting of gelatin. For the titanium material, methacrylate groups were first introduced on the Ti surface through a silanization reaction. The applied functionalities enabled the subsequent immobilization of methacrylamide modified gelatin. Both surface modified materials were characterized in depth using atomic force microscopy, static contact angle measurements, confocal fluorescence microscopy, attenuated total reflection infrared spectroscopy and X-ray photo-electron spectroscopy. The results indicated that the strategies elaborated for both material classes are suitable to apply stable gelatin coatings. Interestingly, depending on the material class studied, not all surface analysis techniques are applicable.

  9. MindSeer: a portable and extensible tool for visualization of structural and functional neuroimaging data

    Directory of Open Access Journals (Sweden)

    Brinkley James F

    2007-10-01

    Full Text Available Abstract Background Three-dimensional (3-D visualization of multimodality neuroimaging data provides a powerful technique for viewing the relationship between structure and function. A number of applications are available that include some aspect of 3-D visualization, including both free and commercial products. These applications range from highly specific programs for a single modality, to general purpose toolkits that include many image processing functions in addition to visualization. However, few if any of these combine both stand-alone and remote multi-modality visualization in an open source, portable and extensible tool that is easy to install and use, yet can be included as a component of a larger information system. Results We have developed a new open source multimodality 3-D visualization application, called MindSeer, that has these features: integrated and interactive 3-D volume and surface visualization, Java and Java3D for true cross-platform portability, one-click installation and startup, integrated data management to help organize large studies, extensibility through plugins, transparent remote visualization, and the ability to be integrated into larger information management systems. We describe the design and implementation of the system, as well as several case studies that demonstrate its utility. These case studies are available as tutorials or demos on the associated website: http://sig.biostr.washington.edu/projects/MindSeer. Conclusion MindSeer provides a powerful visualization tool for multimodality neuroimaging data. Its architecture and unique features also allow it to be extended into other visualization domains within biomedicine.

  10. Functionality and Performance Visualization of the Distributed High Quality Volume Renderer (HVR)

    KAUST Repository

    Shaheen, Sara

    2012-07-01

    Volume rendering systems are designed to provide means to enable scientists and a variety of experts to interactively explore volume data through 3D views of the volume. However, volume rendering techniques are computationally intensive tasks. Moreover, parallel distributed volume rendering systems and multi-threading architectures were suggested as natural solutions to provide an acceptable volume rendering performance for very large volume data sizes, such as Electron Microscopy data (EM). This in turn adds another level of complexity when developing and manipulating volume rendering systems. Given that distributed parallel volume rendering systems are among the most complex systems to develop, trace and debug, it is obvious that traditional debugging tools do not provide enough support. As a consequence, there is a great demand to provide tools that are able to facilitate the manipulation of such systems. This can be achieved by utilizing the power of compute graphics in designing visual representations that reflect how the system works and that visualize the current performance state of the system.The work presented is categorized within the field of software Visualization, where Visualization is used to serve visualizing and understanding various software. In this thesis, a number of visual representations that reflect a number of functionality and performance aspects of the distributed HVR, a high quality volume renderer system that uses various techniques to visualize large volume sizes interactively. This work is provided to visualize different stages of the parallel volume rendering pipeline of HVR. This is along with means of performance analysis through a number of flexible and dynamic visualizations that reflect the current state of the system and enables manipulation of them at runtime. Those visualization are aimed to facilitate debugging, understanding and analyzing the distributed HVR.

  11. Experimental hydrodynamics of fish locomotion: functional insights from wake visualization.

    Science.gov (United States)

    Drucker, Eliot G; Lauder, George V

    2002-04-01

    Despite enormous progress during the last twenty years in understanding the mechanistic basis of aquatic animal propulsion-a task involving the construction of a substantial data base on patterns of fin and body kinematics and locomotor muscle function-there remains a key area in which biologists have little information: the relationship between propulsor activity and water movement in the wake. How is internal muscular force translated into external force exerted on the water? What is the pattern of fluid force production by different fish fins (e.g., pectoral, caudal, dorsal) and how does swimming force vary with speed and among species? These types of questions have received considerable attention in analyses of terrestrial locomotion where force output by limbs can be measured directly with force plates. But how can forces exerted by animals moving through fluid be measured? The advent of digital particle image velocimetry (DPIV) has provided an experimental hydrodynamic approach for quantifying the locomotor forces of freely moving animals in fluids, and has resulted in significant new insights into the mechanisms of fish propulsion. In this paper we present ten "lessons learned" from the application of DPIV to problems of fish locomotion over the last five years. (1) Three-dimensional DPIV analysis is critical for reconstructing wake geometry. (2) DPIV analysis reveals the orientation of locomotor reaction forces. (3) DPIV analysis allows calculation of the magnitude of locomotor forces. (4) Swimming speed can have a major impact on wake structure. (5) DPIV can reveal interspecific differences in vortex wake morphology. (6) DPIV analysis can provide new insights into the limits to locomotor performance. (7) DPIV demonstrates the functional versatility of fish fins. (8) DPIV reveals hydrodynamic force partitioning among fins. (9) DPIV shows that wake interaction among fins may enhance thrust production. (10) Experimental hydrodynamic analysis can provide

  12. Chemical Visualization of Boolean Functions: A Simple Chemical Computer

    Science.gov (United States)

    Blittersdorf, R.; Müller, J.; Schneider, F. W.

    1995-08-01

    We present a chemical realization of the Boolean functions AND, OR, NAND, and NOR with a neutralization reaction carried out in three coupled continuous flow stirred tank reactors (CSTR). Two of these CSTR's are used as input reactors, the third reactor marks the output. The chemical reaction is the neutralization of hydrochloric acid (HCl) with sodium hydroxide (NaOH) in the presence of phenolphtalein as an indicator, which is red in alkaline solutions and colorless in acidic solutions representing the two binary states 1 and 0, respectively. The time required for a "chemical computation" is determined by the flow rate of reactant solutions into the reactors since the neutralization reaction itself is very fast. While the acid flow to all reactors is equal and constant, the flow rate of NaOH solution controls the states of the input reactors. The connectivities between the input and output reactors determine the flow rate of NaOH solution into the output reactor, according to the chosen Boolean function. Thus the state of the output reactor depends on the states of the input reactors.

  13. The Association between Resting Functional Connectivity and Visual Creativity.

    Science.gov (United States)

    Li, Wenfu; Yang, Junyi; Zhang, Qinglin; Li, Gongying; Qiu, Jiang

    2016-05-03

    Resting-state functional connectivity (RSFC), the temporal correlation of intrinsic activation between different brain regions, has become one of the most fascinating field in the functional imaging studies. To better understand the association between RSFC and individual creativity, we used RSFC and the figure Torrance Tests of Creative Thinking (TTCT-F) to investigate the relationship between creativity measured by TTCT and RSFC within two different brain networks, default mode network and the cognitive control network, in a large healthy sample (304). We took the medial prefrontal cortex (MPFC) and the bilateral dorsolateral prefrontal cortices (DLPFC) to be the seed regions and investigated the association across subjects between the score of TTCT-F and the strength of RSFC between these seed regions and other voxels in the whole brain. Results revealed that the strength of RSFC with the MPFC was significantly and negatively correlated with the score of TTCT-F in the precuneus. Meanwhile, we also found that the strength of RSFC with the left DLPFC was significantly and positively correlated with the score of TTCT-F in the right DLPFC. It suggests that the decreased RSFC within DMN and the increased RSFC within CCN presents a potential interaction mechanism between different region for higher creativity.

  14. The Mozart effect in biofeedback visual rehabilitation: a case report.

    Science.gov (United States)

    Salvatore, Serena; Librando, Aloisa; Esposito, Mariacristina; Vingolo, Enzo M

    2011-01-01

    To evaluate the usefulness of acoustic biofeedback by means of Mozart's Sonata for Two Pianos in D Major K. 448 to maintain and/or restore visual performance in a patient with macular pucker and glaucoma. A 74-year-old patient with open angle glaucoma in both eyes and macular pucker in the right eye (RE) underwent visual rehabilitation with acoustic biofeedback by means of the MAIA™ Vision Training Module (Centervue, Padova, Italy) 10 minutes each eye once a week for 5 weeks. The patient was asked to move his eyes according to a sound which changed into Mozart's Sonata for Two Pianos when the patient locked the fixation target. Best-corrected visual acuity improved in his right eye (RE) and was stable in the left eye (LE). Fixation stability improved in both eyes, and retinal sensitivity decreased in the RE and improved in the LE. The characteristic of the macular pucker did not change during the training as demonstrated with optical coherence tomography. The patient was very satisfied with the training, as demonstrated by a 25-item questionnaire (National Eye Institute - Visual Functioning Questionnaire, NEI-VFQ-25). The patient's reading speed and the character size which he was able to read improved in his RE. Music could enhance synaptic plasticity and affect neural learning and fixation training by means of MAIA vision training. Therefore it can improve visual performance in patients with macular pucker, postpone the surgical time, and assure a better quality of life for the patient.

  15. Visual recovery after perinatal stroke evidenced by functional and diffusion MRI: case report

    Directory of Open Access Journals (Sweden)

    Saudan-Frei Sonja

    2005-09-01

    Full Text Available Abstract Background After perinatal brain injury, clinico-anatomic correlations of functional deficits and brain plasticity remain difficult to evaluate clinically in the young infant. Thus, new non-invasive methods capable of early functional diagnosis are needed in young infants. Case Presentation The visual system recovery in an infant with perinatal stroke is assessed by combining diffusion tensor imaging (DTI and event-related functional MRI (ER-fMRI. All experiments were done at 1.5T. A first DTI experiment was performed at 12 months of age. At 20 months of age, a second DTI experiment was performed and combined with an ER-fMRI experiment with visual stimuli (2 Hz visual flash. At 20 months of age, ER-fMRI showed significant negative activation in the visual cortex of the injured left hemisphere that was not previously observed in the same infant. DTI maps suggest recovery of the optic radiation in the vicinity of the lesion. Optic radiations in the injured hemisphere are more prominent in DTI at 20 months of age than in DTI at 12 months of age. Conclusion Our data indicate that functional cortical recovery is supported by structural modifications that concern major pathways of the visual system. These neuroimaging findings might contribute to elaborate a pertinent strategy in terms of diagnosis and rehabilitation.

  16. Prevalence of increases in functional connectivity in visual, somatosensory and language areas in congenital blindness

    Directory of Open Access Journals (Sweden)

    Lizette eHeine

    2015-07-01

    Full Text Available There is ample evidence that congenitally blind individuals rely more strongly on non-visual information compared to sighted controls when interacting with the outside world. Although brain imaging studies indicate that congenitally blind individuals recruit occipital areas when performing various non-visual and cognitive tasks, it remains unclear through which pathways this is accomplished. To address this question, we compared resting state functional connectivity in a group of congenitally blind and matched sighted control subjects. We used a seed-based analysis with a priori specified regions-of-interest (ROIs within visual, somato-sensory, auditory and language areas. Between-group comparisons revealed increased functional connectivity within both the ventral and the dorsal visual streams in blind participants, whereas connectivity between the two streams was reduced. In addition, our data revealed stronger functional connectivity in blind participants between the visual ROIs and areas implicated in language and tactile (Braille processing such as the inferior frontal gyrus (Broca’s area, thalamus, supramarginal gyrus and cerebellum. The observed group differences underscore the extent of the cross-modal reorganisation in the brain and the supra-modal function of the occipital cortex in congenitally blind individuals.

  17. Visual activation in infants and young children studied by functional magnetic resonance imaging

    DEFF Research Database (Denmark)

    Born, Alfred Peter; Leth, H; Miranda Gimenez-Ricco, Maria Jo

    1998-01-01

    The purpose of this study was to determine whether visual stimulation in sleeping infants and young children can be examined by functional magnetic resonance imaging. We studied 17 children, aged 3 d to 48 mo, and three healthy adults. Visual stimulation was performed with 8-Hz flickering light...... through the sleeping childs' closed eyelids. Functional magnetic resonance imaging was performed with a gradient echoplanar sequence in a l.5-T magnetic resonance scanner. Six subjects were excluded because of movement artifacts; the youngest infant showed no response. In 10 children, we could demonstrate...... it was restricted to the anterior and medial part of the calcarine sulcus in the younger infants. This may reflect a different functional organization of the young child's visual cortex or the on-going retinal development....

  18. Visual object agnosia and pure word alexia: correlation of functional magnetic resonance imaging and lesion localization.

    Science.gov (United States)

    Salvan, Carmen V; Ulmer, John L; DeYoe, Edgar A; Wascher, Thomas; Mathews, Vincent P; Lewis, James W; Prost, Robert W

    2004-01-01

    We present a case of a 64-year-old, right-handed female with a metastatic breast cancer lesion involving the left posterior inferior temporal lobe causing complete loss of the ability to recognize visually common objects and words. After her symptoms resolved on corticosteroid therapy, functional magnetic resonance imaging (fMRI) mapping demonstrated strong left-hemispheric dominance for word recognition and right-hemispheric dominance for object recognition. The case illustrates the relationships among ventral occipito-temporal cortical activation, lesion localization, and lesion-induced deficits of higher visual function. The relationship between hemispheric dominance determined by fMRI and risk of postoperative deficit depends on the specific visual function of interest.

  19. Augmented visual feedback counteracts the effects of surface muscular functional electrical stimulation on physiological tremor.

    Science.gov (United States)

    Grimaldi, Giuliana; Fernandez, Alfredo; Manto, Mario

    2013-09-24

    Recent studies suggest that surface muscular functional electrical stimulation (FES) might suppress neurological upper limb tremor. We assessed its effects on upper limb physiological tremor, which is mainly driven by mechanical-reflex oscillations. We investigated the interaction between FES and augmented visual feedback, since (a) most daily activities are performed using visual cues, and (b) augmented visual feedback exacerbates upper limb tremor. 10 healthy subjects (23.4 ± 7.7 years) performed 2 postural tasks with combinations of FES (4 sites; frequency of stimulation: 30 Hz; pulse width: 300 microsec; range of current delivered 10-34 mAmp) and augmented visual feedback. Spectral analysis of tremor showed a decrease of power spectral density to 62.18% (p = 0.01), of the integral in the 8-12 Hz frequency band to 57.67% (p = 0.003), and of tremor root mean square (RMS) to 57.16% (p = 0.002) during FES, without any changes in tremor frequency. Augmented visual feedback blocked the beneficial effect of FES, as confirmed by power spectral analysis (p = 0.01). We found a statistically significant interaction between augmented visual feedback and electrical stimulation (p = 0.039). Augmented visual feedback antagonizes the effects of FES on physiological tremor. The absence of changes of peak frequency argues against an effect of FES on mechanical properties of the upper limb.

  20. Visual Imagery and False Memory for Pictures: A Functional Magnetic Resonance Imaging Study in Healthy Participants

    Science.gov (United States)

    Stephan-Otto, Christian; Siddi, Sara; Senior, Carl; Muñoz-Samons, Daniel; Ochoa, Susana; Sánchez-Laforga, Ana María; Brébion, Gildas

    2017-01-01

    Background Visual mental imagery might be critical in the ability to discriminate imagined from perceived pictures. Our aim was to investigate the neural bases of this specific type of reality-monitoring process in individuals with high visual imagery abilities. Methods A reality-monitoring task was administered to twenty-six healthy participants using functional magnetic resonance imaging. During the encoding phase, 45 words designating common items, and 45 pictures of other common items, were presented in random order. During the recall phase, participants were required to remember whether a picture of the item had been presented, or only a word. Two subgroups of participants with a propensity for high vs. low visual imagery were contrasted. Results Activation of the amygdala, left inferior occipital gyrus, insula, and precuneus were observed when high visual imagers encoded words later remembered as pictures. At the recall phase, these same participants activated the middle frontal gyrus and inferior and superior parietal lobes when erroneously remembering pictures. Conclusions The formation of visual mental images might activate visual brain areas as well as structures involved in emotional processing. High visual imagers demonstrate increased activation of a fronto-parietal source-monitoring network that enables distinction between imagined and perceived pictures. PMID:28046076

  1. Crossmodal enhancement of visual orientation discrimination by looming sounds requires functional activation of primary visual areas: a case study.

    Science.gov (United States)

    Cecere, Roberto; Romei, Vincenzo; Bertini, Caterina; Làdavas, Elisabetta

    2014-04-01

    Approaching or looming sounds are salient, potentially threatening stimuli with particular impact on visual processing. The early crossmodal effects by looming sounds (Romei, Murray, Cappe, & Thut, 2009) and their selective impact on visual orientation discrimination (Leo, Romei, Freeman, Ladavas, & Driver, 2011) suggest that these multisensory interactions may take place already within low-level visual cortices. To investigate this hypothesis, we tested a patient (SDV) with bilateral occipital lesion and spared residual portions of V1/V2. Accordingly, SDV׳s visual perimetry revealed blindness of the central visual field with some residual peripheral vision. In two experiments we tested for the influence of looming vs. receding and stationary sounds on SDV׳s line orientation discrimination (orientation discrimination experiment) and visual detection abilities (detection experiment) in the preserved or blind portions of the visual field, corresponding to spared and lesioned areas of V1, respectively. In the visual orientation discrimination experiment we found that SDV visual orientation sensitivity significantly improved for visual targets paired with looming sounds but only for lines presented in the partially preserved visual field. In the visual detection experiment, where SDV was required to simply detect the same stimuli presented in the orientation discrimination experiment, a generalised sound-induced visual improvement both in the intact and in blind portion of the visual field was observed. These results provide direct evidence that early visual areas are critically involved in crossmodal modulation of visual orientation sensitivity by looming sounds. Thus, a lesion in V1 prevents the enhancement of visual orientation sensitivity. In contrast, the same lesion does not prevent the visual detection enhancement by a sound, probably due to alternative visual pathways (e.g. retino-colliculo-extrastriate) which are usually spared in these patients and able to

  2. Visual working memory load-related changes in neural activity and functional connectivity.

    Directory of Open Access Journals (Sweden)

    Ling Li

    Full Text Available BACKGROUND: Visual working memory (VWM helps us store visual information to prepare for subsequent behavior. The neuronal mechanisms for sustaining coherent visual information and the mechanisms for limited VWM capacity have remained uncharacterized. Although numerous studies have utilized behavioral accuracy, neural activity, and connectivity to explore the mechanism of VWM retention, little is known about the load-related changes in functional connectivity for hemi-field VWM retention. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we recorded electroencephalography (EEG from 14 normal young adults while they performed a bilateral visual field memory task. Subjects had more rapid and accurate responses to the left visual field (LVF memory condition. The difference in mean amplitude between the ipsilateral and contralateral event-related potential (ERP at parietal-occipital electrodes in retention interval period was obtained with six different memory loads. Functional connectivity between 128 scalp regions was measured by EEG phase synchronization in the theta- (4-8 Hz, alpha- (8-12 Hz, beta- (12-32 Hz, and gamma- (32-40 Hz frequency bands. The resulting matrices were converted to graphs, and mean degree, clustering coefficient and shortest path length was computed as a function of memory load. The results showed that brain networks of theta-, alpha-, beta-, and gamma- frequency bands were load-dependent and visual-field dependent. The networks of theta- and alpha- bands phase synchrony were most predominant in retention period for right visual field (RVF WM than for LVF WM. Furthermore, only for RVF memory condition, brain network density of theta-band during the retention interval were linked to the delay of behavior reaction time, and the topological property of alpha-band network was negative correlation with behavior accuracy. CONCLUSIONS/SIGNIFICANCE: We suggest that the differences in theta- and alpha- bands between LVF and RVF

  3. Stereoscopic Three-Dimensional Visualization Applied to Multimodal Brain Images: Clinical Applications and a Functional Connectivity Atlas.

    Directory of Open Access Journals (Sweden)

    Gonzalo M Rojas

    2014-11-01

    Full Text Available Effective visualization is central to the exploration and comprehension of brain imaging data. While MRI data are acquired in three-dimensional space, the methods for visualizing such data have rarely taken advantage of three-dimensional stereoscopic technologies. We present here results of stereoscopic visualization of clinical data, as well as an atlas of whole-brain functional connectivity. In comparison with traditional 3D rendering techniques, we demonstrate the utility of stereoscopic visualizations to provide an intuitive description of the exact location and the relative sizes of various brain landmarks, structures and lesions. In the case of resting state fMRI, stereoscopic 3D visualization facilitated comprehension of the anatomical position of complex large-scale functional connectivity patterns. Overall, stereoscopic visualization improves the intuitive visual comprehension of image contents, and brings increased dimensionality to visualization of traditional MRI data, as well as patterns of functional connectivity.

  4. Stereoscopic three-dimensional visualization applied to multimodal brain images: clinical applications and a functional connectivity atlas.

    Science.gov (United States)

    Rojas, Gonzalo M; Gálvez, Marcelo; Vega Potler, Natan; Craddock, R Cameron; Margulies, Daniel S; Castellanos, F Xavier; Milham, Michael P

    2014-01-01

    Effective visualization is central to the exploration and comprehension of brain imaging data. While MRI data are acquired in three-dimensional space, the methods for visualizing such data have rarely taken advantage of three-dimensional stereoscopic technologies. We present here results of stereoscopic visualization of clinical data, as well as an atlas of whole-brain functional connectivity. In comparison with traditional 3D rendering techniques, we demonstrate the utility of stereoscopic visualizations to provide an intuitive description of the exact location and the relative sizes of various brain landmarks, structures and lesions. In the case of resting state fMRI, stereoscopic 3D visualization facilitated comprehension of the anatomical position of complex large-scale functional connectivity patterns. Overall, stereoscopic visualization improves the intuitive visual comprehension of image contents, and brings increased dimensionality to visualization of traditional MRI data, as well as patterns of functional connectivity.

  5. Cross-Modal Functional Reorganization of Visual and Auditory Cortex in Adult Cochlear Implant Users Identified with fNIRS.

    Science.gov (United States)

    Chen, Ling-Chia; Sandmann, Pascale; Thorne, Jeremy D; Bleichner, Martin G; Debener, Stefan

    2016-01-01

    Cochlear implant (CI) users show higher auditory-evoked activations in visual cortex and higher visual-evoked activation in auditory cortex compared to normal hearing (NH) controls, reflecting functional reorganization of both visual and auditory modalities. Visual-evoked activation in auditory cortex is a maladaptive functional reorganization whereas auditory-evoked activation in visual cortex is beneficial for speech recognition in CI users. We investigated their joint influence on CI users' speech recognition, by testing 20 postlingually deafened CI users and 20 NH controls with functional near-infrared spectroscopy (fNIRS). Optodes were placed over occipital and temporal areas to measure visual and auditory responses when presenting visual checkerboard and auditory word stimuli. Higher cross-modal activations were confirmed in both auditory and visual cortex for CI users compared to NH controls, demonstrating that functional reorganization of both auditory and visual cortex can be identified with fNIRS. Additionally, the combined reorganization of auditory and visual cortex was found to be associated with speech recognition performance. Speech performance was good as long as the beneficial auditory-evoked activation in visual cortex was higher than the visual-evoked activation in the auditory cortex. These results indicate the importance of considering cross-modal activations in both visual and auditory cortex for potential clinical outcome estimation.

  6. Cross-Modal Functional Reorganization of Visual and Auditory Cortex in Adult Cochlear Implant Users Identified with fNIRS

    Directory of Open Access Journals (Sweden)

    Ling-Chia Chen

    2016-01-01

    Full Text Available Cochlear implant (CI users show higher auditory-evoked activations in visual cortex and higher visual-evoked activation in auditory cortex compared to normal hearing (NH controls, reflecting functional reorganization of both visual and auditory modalities. Visual-evoked activation in auditory cortex is a maladaptive functional reorganization whereas auditory-evoked activation in visual cortex is beneficial for speech recognition in CI users. We investigated their joint influence on CI users’ speech recognition, by testing 20 postlingually deafened CI users and 20 NH controls with functional near-infrared spectroscopy (fNIRS. Optodes were placed over occipital and temporal areas to measure visual and auditory responses when presenting visual checkerboard and auditory word stimuli. Higher cross-modal activations were confirmed in both auditory and visual cortex for CI users compared to NH controls, demonstrating that functional reorganization of both auditory and visual cortex can be identified with fNIRS. Additionally, the combined reorganization of auditory and visual cortex was found to be associated with speech recognition performance. Speech performance was good as long as the beneficial auditory-evoked activation in visual cortex was higher than the visual-evoked activation in the auditory cortex. These results indicate the importance of considering cross-modal activations in both visual and auditory cortex for potential clinical outcome estimation.

  7. Reconfiguration of the Brain Functional Network Associated with Visual Task Demands.

    Science.gov (United States)

    Wen, Xue; Zhang, Delong; Liang, Bishan; Zhang, Ruibin; Wang, Zengjian; Wang, Junjing; Liu, Ming; Huang, Ruiwang

    2015-01-01

    Neuroimaging studies have demonstrated that the topological properties of resting-state brain functional networks are modulated through task performances. However, the reconfiguration of functional networks associated with distinct degrees of task demands is not well understood. In the present study, we acquired fMRI data from 18 healthy adult volunteers during resting-state (RS) and two visual tasks (i.e., visual stimulus watching, VSW; and visual stimulus decision, VSD). Subsequently, we constructed the functional brain networks associated with these three conditions and analyzed the changes in the topological properties (e.g., network efficiency, wiring-cost, modularity, and robustness) among them. Although the small-world attributes were preserved qualitatively across the functional networks of the three conditions, changes in the topological properties were also observed. Compared with the resting-state, the functional networks associated with the visual tasks exhibited significantly increased network efficiency and wiring-cost, but decreased modularity and network robustness. The changes in the task-related topological properties were modulated according to the task complexity (i.e., from RS to VSW and VSD). Moreover, at the regional level, we observed that the increased nodal efficiencies in the visual and working memory regions were positively associated with the increase in task complexity. Together, these results suggest that the increased efficiency of the functional brain network and higher wiring-cost were observed to afford the demands of visual tasks. These observations provide further insights into the mechanisms underlying the reconfiguration of the brain network during task performance.

  8. The effect of visual experience on the development of functional architecture in hMT+.

    Science.gov (United States)

    Ricciardi, Emiliano; Vanello, Nicola; Sani, Lorenzo; Gentili, Claudio; Scilingo, Enzo Pasquale; Landini, Luigi; Guazzelli, Mario; Bicchi, Antonio; Haxby, James V; Pietrini, Pietro

    2007-12-01

    We investigated whether the visual hMT+ cortex plays a role in supramodal representation of sensory flow, not mediated by visual mental imagery. We used functional magnetic resonance imaging to measure neural activity in sighted and congenitally blind individuals during passive perception of optic and tactile flows. Visual motion-responsive cortex, including hMT+, was identified in the lateral occipital and inferior temporal cortices of the sighted subjects by response to optic flow. Tactile flow perception in sighted subjects activated the more anterior part of these cortical regions but deactivated the more posterior part. By contrast, perception of tactile flow in blind subjects activated the full extent, including the more posterior part. These results demonstrate that activation of hMT+ and surrounding cortex by tactile flow is not mediated by visual mental imagery and that the functional organization of hMT+ can develop to subserve tactile flow perception in the absence of any visual experience. Moreover, visual experience leads to a segregation of the motion-responsive occipitotemporal cortex into an anterior subregion involved in the representation of both optic and tactile flows and a posterior subregion that processes optic flow only.

  9. Frequency band-importance functions for auditory and auditory-visual speech recognition

    Science.gov (United States)

    Grant, Ken W.

    2005-04-01

    In many everyday listening environments, speech communication involves the integration of both acoustic and visual speech cues. This is especially true in noisy and reverberant environments where the speech signal is highly degraded, or when the listener has a hearing impairment. Understanding the mechanisms involved in auditory-visual integration is a primary interest of this work. Of particular interest is whether listeners are able to allocate their attention to various frequency regions of the speech signal differently under auditory-visual conditions and auditory-alone conditions. For auditory speech recognition, the most important frequency regions tend to be around 1500-3000 Hz, corresponding roughly to important acoustic cues for place of articulation. The purpose of this study is to determine the most important frequency region under auditory-visual speech conditions. Frequency band-importance functions for auditory and auditory-visual conditions were obtained by having subjects identify speech tokens under conditions where the speech-to-noise ratio of different parts of the speech spectrum is independently and randomly varied on every trial. Point biserial correlations were computed for each separate spectral region and the normalized correlations are interpreted as weights indicating the importance of each region. Relations among frequency-importance functions for auditory and auditory-visual conditions will be discussed.

  10. Functional size of human visual area V1: a neural correlate of top-down attention.

    Science.gov (United States)

    Verghese, Ashika; Kolbe, Scott C; Anderson, Andrew J; Egan, Gary F; Vidyasagar, Trichur R

    2014-06-01

    Heavy demands are placed on the brain's attentional capacity when selecting a target item in a cluttered visual scene, or when reading. It is widely accepted that such attentional selection is mediated by top-down signals from higher cortical areas to early visual areas such as the primary visual cortex (V1). Further, it has also been reported that there is considerable variation in the surface area of V1. This variation may impact on either the number or specificity of attentional feedback signals and, thereby, the efficiency of attentional mechanisms. In this study, we investigated whether individual differences between humans performing attention-demanding tasks can be related to the functional area of V1. We found that those with a larger representation in V1 of the central 12° of the visual field as measured using BOLD signals from fMRI were able to perform a serial search task at a faster rate. In line with recent suggestions of the vital role of visuo-spatial attention in reading, the speed of reading showed a strong positive correlation with the speed of visual search, although it showed little correlation with the size of V1. The results support the idea that the functional size of the primary visual cortex is an important determinant of the efficiency of selective spatial attention for simple tasks, and that the attentional processing required for complex tasks like reading are to a large extent determined by other brain areas and inter-areal connections.

  11. Early-stage visual processing abnormalities in high-functioning autism spectrum disorder (ASD).

    Science.gov (United States)

    Baruth, Joshua M; Casanova, Manuel F; Sears, Lonnie; Sokhadze, Estate

    2010-06-01

    It has been reported that individuals with autism spectrum disorder (ASD) have abnormal responses to the sensory environment. For these individuals sensory overload can impair functioning, raise physiological stress, and adversely affect social interaction. Early-stage (i.e. within 200ms of stimulus onset) auditory processing abnormalities have been widely examined in ASD using event-related potentials (ERP), while ERP studies investigating early-stage visual processing in ASD are less frequent. We wanted to test the hypothesis of early-stage visual processing abnormalities in ASD by investigating ERPs elicited in a visual oddball task using illusory figures. Our results indicate that individuals with ASD have abnormally large cortical responses to task irrelevant stimuli over both parieto-occipital and frontal regions-of-interest (ROI) during early stages of visual processing compared to the control group. Furthermore, ASD patients showed signs of an overall disruption in stimulus discrimination, and had a significantly higher rate of motor response errors.

  12. Functional magnetic resonance imaging of the normal and abnormal visual system in early life

    DEFF Research Database (Denmark)

    Born, A.P.; Miranda Gimenez-Ricco, Maria Jo; Rostrup, Egill

    2000-01-01

    Functional magnetic resonance imaging (fMRI) in young children may provide information about the development of the visual cortex, and may have predictive value for later visual performance. The purpose of this study was to evaluate the usefulness of fMRI for examining cerebral processing of vision...... activation on the healthy side. In future prospective studies, results from the period from birth to six months of age should be interpreted with caution, as inter-individual variation of cortical development may be confused with functional deficit...

  13. Privileged Functional Connectivity between the Visual Word Form Area and the Language System.

    Science.gov (United States)

    Stevens, W Dale; Kravitz, Dwight J; Peng, Cynthia S; Tessler, Michael Henry; Martin, Alex

    2017-05-24

    The visual word form area (VWFA) is a region in the left occipitotemporal sulcus of literate individuals that is purportedly specialized for visual word recognition. However, there is considerable controversy about its functional specificity and connectivity, with some arguing that it serves as a domain-general, rather than word-specific, visual processor. The VWFA is a critical region for testing hypotheses about the nature of cortical organization, because it is known to develop only through experience (i.e., reading acquisition), and widespread literacy is too recent to have influenced genetic determinants of brain organization. Using a combination of advanced fMRI analysis techniques, including individual functional localization, multivoxel pattern analysis, and high-resolution resting-state functional connectivity (RSFC) analyses, with data from 33 healthy adult human participants, we demonstrate that (1) the VWFA can discriminate words from nonword letter strings (pseudowords); (2) the VWFA has preferential RSFC with Wernicke's area and other core regions of the language system; and (3) the strength of the RSFC between the VWFA and Wernicke's area predicts performance on a semantic classification task with words but not other categories of visual stimuli. Our results are consistent with the hypothesis that the VWFA is specialized for lexical processing of real words because of its functional connectivity with Wernicke's area.SIGNIFICANCE STATEMENT The visual word form area (VWFA) is critical for determining the nature of category-related organization of the ventral visual system. However, its functional specificity and connectivity are fiercely debated. Recent work concluded that the VWFA is a domain-general, rather than word-specific, visual processor with no preferential functional connectivity with the language system. Using more advanced techniques, our results stand in stark contrast to these earlier findings. We demonstrate that the VWFA is highly

  14. Visualization of superluminal pulses inside a white light cavity using plane wave spatio temporal transfer functions.

    Science.gov (United States)

    Yum, H N; Jang, Y J; Liu, X; Shahriar, M S

    2012-08-13

    In a white light cavity (WLC), the group velocity is superluminal over a finite bandwidth. For a WLC-based data buffering system we recently proposed, it is important to visualize the behavior of pulses inside such a cavity. The conventional plane wave transfer functions, valid only over space that is translationally invariant, cannot be used for the space inside WLC or any cavity, which is translationally variant. Here, we develop the plane wave spatio temporal transfer function (PWSTTF) method to solve this problem, and produce visual representations of a Gaussian input pulse incident on a WLC, for all times and positions.

  15. LSD alters eyes-closed functional connectivity within the early visual cortex in a retinotopic fashion.

    Science.gov (United States)

    Roseman, Leor; Sereno, Martin I; Leech, Robert; Kaelen, Mendel; Orban, Csaba; McGonigle, John; Feilding, Amanda; Nutt, David J; Carhart-Harris, Robin L

    2016-08-01

    The question of how spatially organized activity in the visual cortex behaves during eyes-closed, lysergic acid diethylamide (LSD)-induced "psychedelic imagery" (e.g., visions of geometric patterns and more complex phenomena) has never been empirically addressed, although it has been proposed that under psychedelics, with eyes-closed, the brain may function "as if" there is visual input when there is none. In this work, resting-state functional connectivity (RSFC) data was analyzed from 10 healthy subjects under the influence of LSD and, separately, placebo. It was suspected that eyes-closed psychedelic imagery might involve transient local retinotopic activation, of the sort typically associated with visual stimulation. To test this, it was hypothesized that, under LSD, patches of the visual cortex with congruent retinotopic representations would show greater RSFC than incongruent patches. Using a retinotopic localizer performed during a nondrug baseline condition, nonadjacent patches of V1 and V3 that represent the vertical or the horizontal meridians of the visual field were identified. Subsequently, RSFC between V1 and V3 was measured with respect to these a priori identified patches. Consistent with our prior hypothesis, the difference between RSFC of patches with congruent retinotopic specificity (horizontal-horizontal and vertical-vertical) and those with incongruent specificity (horizontal-vertical and vertical-horizontal) increased significantly under LSD relative to placebo, suggesting that activity within the visual cortex becomes more dependent on its intrinsic retinotopic organization in the drug condition. This result may indicate that under LSD, with eyes-closed, the early visual system behaves as if it were seeing spatially localized visual inputs. Hum Brain Mapp 37:3031-3040, 2016. © 2016 Wiley Periodicals, Inc.

  16. Protection of visual functions by human neural progenitors in a rat model of retinal disease.

    Directory of Open Access Journals (Sweden)

    David M Gamm

    Full Text Available BACKGROUND: A promising clinical application for stem and progenitor cell transplantation is in rescue therapy for degenerative diseases. This strategy seeks to preserve rather than restore host tissue function by taking advantage of unique properties often displayed by these versatile cells. In studies using different neurodegenerative disease models, transplanted human neural progenitor cells (hNPC protected dying host neurons within both the brain and spinal cord. Based on these reports, we explored the potential of hNPC transplantation to rescue visual function in an animal model of retinal degeneration, the Royal College of Surgeons rat. METHODOLOGY/PRINCIPAL FINDINGS: Animals received unilateral subretinal injections of hNPC or medium alone at an age preceding major photoreceptor loss. Principal outcomes were quantified using electroretinography, visual acuity measurements and luminance threshold recordings from the superior colliculus. At 90-100 days postnatal, a time point when untreated rats exhibit little or no retinal or visual function, hNPC-treated eyes retained substantial retinal electrical activity and visual field with near-normal visual acuity. Functional efficacy was further enhanced when hNPC were genetically engineered to secrete glial cell line-derived neurotrophic factor. Histological examination at 150 days postnatal showed hNPC had formed a nearly continuous pigmented layer between the neural retina and retinal pigment epithelium, as well as distributed within the inner retina. A concomitant preservation of host cone photoreceptors was also observed. CONCLUSIONS/SIGNIFICANCE: Wild type and genetically modified human neural progenitor cells survive for prolonged periods, migrate extensively, secrete growth factors and rescue visual functions following subretinal transplantation in the Royal College of Surgeons rat. These results underscore the potential therapeutic utility of hNPC in the treatment of retinal degenerative

  17. Functional connectivity of visual cortex in the blind follows retinotopic organization principles.

    Science.gov (United States)

    Striem-Amit, Ella; Ovadia-Caro, Smadar; Caramazza, Alfonso; Margulies, Daniel S; Villringer, Arno; Amedi, Amir

    2015-06-01

    Is visual input during critical periods of development crucial for the emergence of the fundamental topographical mapping of the visual cortex? And would this structure be retained throughout life-long blindness or would it fade as a result of plastic, use-based reorganization? We used functional connectivity magnetic resonance imaging based on intrinsic blood oxygen level-dependent fluctuations to investigate whether significant traces of topographical mapping of the visual scene in the form of retinotopic organization, could be found in congenitally blind adults. A group of 11 fully and congenitally blind subjects and 18 sighted controls were studied. The blind demonstrated an intact functional connectivity network structural organization of the three main retinotopic mapping axes: eccentricity (centre-periphery), laterality (left-right), and elevation (upper-lower) throughout the retinotopic cortex extending to high-level ventral and dorsal streams, including characteristic eccentricity biases in face- and house-selective areas. Functional connectivity-based topographic organization in the visual cortex was indistinguishable from the normally sighted retinotopic functional connectivity structure as indicated by clustering analysis, and was found even in participants who did not have a typical retinal development in utero (microphthalmics). While the internal structural organization of the visual cortex was strikingly similar, the blind exhibited profound differences in functional connectivity to other (non-visual) brain regions as compared to the sighted, which were specific to portions of V1. Central V1 was more connected to language areas but peripheral V1 to spatial attention and control networks. These findings suggest that current accounts of critical periods and experience-dependent development should be revisited even for primary sensory areas, in that the connectivity basis for visual cortex large-scale topographical organization can develop without any

  18. [The impact of endovascular intervention on visual functions in patients with traumatic carotid-cavernous anastomosis].

    Science.gov (United States)

    Ryzhova, I P

    1997-01-01

    In 217 patients with traumatic carotid-cavernous anastomosis (TCCA) the visual functions investigation before and after endovascular intervention conduction for the anastomosis exclusion was done. Cessation of the noise in the head synchronous with a pulse, decrease of disappearance of an exophthalmus of an eye or superior optical vein pulsation, of congestional appearance in the orbit, were the signs of the complete anastomosis exclusion. Rehabilitation or increase of visual acuity, improvement of an eye fundus ophthalmological picture, vascular index normalization were noted during deep ophthalmological investigation. Decrease of the blind spot parameters was an objective index of the visual functions rehabilitation, witnessing the disappearance of optical nerve disc (OND) oedema, contrast frequential characteristics normalization, critical frequency of light flashings radiance (CFLFR) rise, decrease of a papillary cycle time (PCT). Studying of the parameters mentioned have special significance for the estimation of postoperative conservative therapy efficiency.

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

  1. Can common functional gene variants affect visual discrimination in metacontrast masking?

    Directory of Open Access Journals (Sweden)

    Margus Maksimov

    Full Text Available Mechanisms of visual perception should be robustly fast and provide veridical information about environmental objects in order to facilitate survival and successful coping. Because species-specific brain mechanisms for fast vision must have evolved under heavy pressure for efficiency, it has been held that different human individuals see the physical world in the same way and produce psychophysical functions of visual discrimination that are qualitatively the same. For many years, this assumption has been implicitly accepted in vision research studying extremely fast, basic visual processes, including studies of visual masking. However, in recent studies of metacontrast masking surprisingly robust individual differences in the qualitative aspects of subjects' performance have been found. As the basic species-specific visual functions very likely are based on universal brain mechanisms of vision, these differences probably are the outcome of variability in ontogenetic development (i.e., formation of idiosyncrasic skills of perception. Such developmental differences can be brought about by variants of genes that are differentially expressed in the course of CNS development. The objective of this study was to assess whether visual discrimination in metacontrast masking is related to three widely studied genetic polymorphisms implicated in brain function and used here as independent variables. The findings suggest no main effects of BDNF Val66Met, NRG1/rs6994992, or 5-HTTLPR polymorphisms on metacontrast performance, but several notable interactions of genetic variables with gender, stage of the sequence of experimental trials, perceptual strategies, and target/mask shape congruence were found. Thus, basic behavioral functions of fast vision may be influenced by common genetic variability. Also, when left uncontrolled, genetic factors may seriously confound variables in vision research using masking, obscure clear theoretical interpretation, lead to

  2. Visual-spatial functioning as an early indicator of socioemotional difficulties.

    Science.gov (United States)

    Tonks, James; Yates, Phil; Slater, Alan; Williams, W Huw; Frampton, Ian

    2009-01-01

    As children with acquired brain injuries (ABI) mature to become adolescents they develop a range of previously undetected social and emotional difficulties, which are commonly associated with executive dysfunctions. The authors wanted to determine whether visual-spatial performance is subject to age-related improvement, whether such skills can differentiate between children with ABI and healthy children and whether visual-spatial performance is a correlate of socioemotional functioning. The 'Cube analysis' and 'Dot discrimination' tests from the 'Visual Object Space Perception (VOSP)' battery and the Strengths and Difficulties Questionnaire (SDQ) were administered for 18 children, 9-15 years, with ABI and compared against 67 'healthy' children. Cube analysis scores improved significantly at approximately 10 years old in the control group. The ABI group performed the task significantly poorer than controls. Analysis indicated that visual discrimination skill did not account for performance difficulties. Visual-spatial performance was correlated with greater impact of reported difficulties on the SDQ. Visual-spatial tests are sensitive in differentiating between healthy children and children with ABI. Impairment of visuo-spatial skills may provide an index of psychosocial risk during later teenage years and adulthood.

  3. Structural and functional brain changes beyond visual system in patients with advanced glaucoma.

    Science.gov (United States)

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

    2014-01-01

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

  4. Contingency Mapping: Use of a Novel Visual Support Strategy as an Adjunct to Functional Equivalence Training

    Science.gov (United States)

    Brown, Kenneth E.; Mirenda, Pat

    2006-01-01

    This study evaluated the effectiveness of contingency mapping, a new visual support strategy designed to enhance clients' understanding of the contingencies associated with functional equivalence training (FET). The study was conducted in a general education classroom with an adolescent boy with autism who engaged in prompt dependent behavior. A…

  5. Postoperative recovery of visual function after macula-off rhegmatogenous retinal detachment

    NARCIS (Netherlands)

    van de Put, Mathijs A. J.; Croonen, Danna; Nolte, Ilja M.; Japing, Wouter J.; Hooymans, Johanna M. M.; Los, Leonoor I.

    2014-01-01

    Purpose: To determine which factors affect the recovery of visual function in macula-off rhegmatogenous retinal detachment (RRD). Methods: In a prospective study of forty-five patients with a primary macula-off RRD of 24 hours to 6 weeks duration, the height of the macular detachment was determined

  6. On the Functional Neuroanatomy of Visual Word Processing: Effects of Case and Letter Deviance

    Science.gov (United States)

    Kronbichler, Martin; Klackl, Johannes; Richlan, Fabio; Schurz, Matthias; Staffen, Wolfgang; Ladurner, Gunther; Wimmer, Heinz

    2009-01-01

    This functional magnetic resonance imaging study contrasted case-deviant and letter-deviant forms with familiar forms of the same phonological words (e.g., "TaXi" and "Taksi" vs. "Taxi") and found that both types of deviance led to increased activation in a left occipito-temporal region, corresponding to the visual word form area (VWFA). The…

  7. Prevalence of increases in functional connectivity in visual, somatosensory and language areas in congenital blindness

    DEFF Research Database (Denmark)

    Heine, Lizette; Bahri, Mohamed A; Cavaliere, Carlo

    2015-01-01

    non-visual and cognitive tasks, it remains unclear through which pathways this is accomplished. To address this question, we compared resting state functional connectivity in a group of congenital blind and matched sighted control subjects. We used a seed-based analysis with a priori specified regions...

  8. Investigation of human visual cortex responses to flickering light using functional near infrared spectroscopy and constrained ICA

    OpenAIRE

    Nguyen Duc Thang; Vo Van Toi; Le Giang Tran; Nguyen Huynh Minh Tam; Lan Anh Trinh

    2014-01-01

    The human visual sensitivity to the flickering light has been under investigation for decades. The finding of research in this area can contribute to the understanding of human visual system mechanism and visual disorders, and establishing diagnosis and treatment of diseases. The aim of this study is to investigate the effects of the flickering light to the visual cortex by monitoring the hemodynamic responses of the brain with the functional near infrared spectroscopy (fNIRS) method. Since t...

  9. Visual function and cortical organization in carriers of blue cone monochromacy.

    Science.gov (United States)

    Rossi, Ethan A; Achtman, Rebecca L; Guidon, Arnaud; Williams, David R; Roorda, Austin; Bavelier, Daphne; Carroll, Joseph

    2013-01-01

    Carriers of blue cone monochromacy have fewer cone photoreceptors than normal. Here we examine how this disruption at the level of the retina affects visual function and cortical organization in these individuals. Visual resolution and contrast sensitivity was measured at the preferred retinal locus of fixation and visual resolution was tested at two eccentric locations (2.5° and 8°) with spectacle correction only. Adaptive optics corrected resolution acuity and cone spacing were simultaneously measured at several locations within the central fovea with adaptive optics scanning laser ophthalmoscopy (AOSLO). Fixation stability was assessed by extracting eye motion data from AOSLO videos. Retinotopic mapping using fMRI was carried out to estimate the area of early cortical regions, including that of the foveal confluence. Without adaptive optics correction, BCM carriers appeared to have normal visual function, with normal contrast sensitivity and visual resolution, but with AO-correction, visual resolution was significantly worse than normal. This resolution deficit is not explained by cone loss alone and is suggestive of an associated loss of retinal ganglion cells. However, despite evidence suggesting a reduction in the number of retinal ganglion cells, retinotopic mapping showed no reduction in the cortical area of the foveal confluence. These results suggest that ganglion cell density may not govern the foveal overrepresentation in the cortex. We propose that it is not the number of afferents, but rather the content of the information relayed to the cortex from the retina across the visual field that governs cortical magnification, as under normal viewing conditions this information is similar in both BCM carriers and normal controls.

  10. Visual function and cortical organization in carriers of blue cone monochromacy.

    Directory of Open Access Journals (Sweden)

    Ethan A Rossi

    Full Text Available Carriers of blue cone monochromacy have fewer cone photoreceptors than normal. Here we examine how this disruption at the level of the retina affects visual function and cortical organization in these individuals. Visual resolution and contrast sensitivity was measured at the preferred retinal locus of fixation and visual resolution was tested at two eccentric locations (2.5° and 8° with spectacle correction only. Adaptive optics corrected resolution acuity and cone spacing were simultaneously measured at several locations within the central fovea with adaptive optics scanning laser ophthalmoscopy (AOSLO. Fixation stability was assessed by extracting eye motion data from AOSLO videos. Retinotopic mapping using fMRI was carried out to estimate the area of early cortical regions, including that of the foveal confluence. Without adaptive optics correction, BCM carriers appeared to have normal visual function, with normal contrast sensitivity and visual resolution, but with AO-correction, visual resolution was significantly worse than normal. This resolution deficit is not explained by cone loss alone and is suggestive of an associated loss of retinal ganglion cells. However, despite evidence suggesting a reduction in the number of retinal ganglion cells, retinotopic mapping showed no reduction in the cortical area of the foveal confluence. These results suggest that ganglion cell density may not govern the foveal overrepresentation in the cortex. We propose that it is not the number of afferents, but rather the content of the information relayed to the cortex from the retina across the visual field that governs cortical magnification, as under normal viewing conditions this information is similar in both BCM carriers and normal controls.

  11. New portable tool to screen vestibular and visual function--National Institutes of Health Toolbox initiative.

    Science.gov (United States)

    Rine, Rose Marie; Roberts, Dale; Corbin, Bree A; McKean-Cowdin, Roberta; Varma, Rohit; Beaumont, Jennifer; Slotkin, Jerry; Schubert, Michael C

    2012-01-01

    As part of the National Institutes of Health Toolbox initiative, we developed a low-cost, easy-to-administer, and time-efficient test of vestibular and visual function. A computerized test of dynamic visual acuity (cDVA) was used to measure the difference in visual acuity between head still and moving in yaw. Participants included 318 individuals, aged 3 to 85 years (301 without and 17 with vestibular pathology). Adults used Early Treatment of Diabetic Retinopathy Study (ETDRS) optotypes; children used ETDRS, Lea, and HOTV optotypes. Bithermal calorics, rotational chair, and light box testing were used to validate the cDVA. Analysis revealed that the cDVA test is reliable for static (intraclass correlation coefficient [ICC] >/= 0.64) and dynamic (ICC >/= 0.43-0.75) visual acuity. Children younger than 6 years old were more likely to complete cDVA with Lea optotypes, but reliability and correlation with ETDRS was better using HOTV optotypes. The high correlation between static acuity and light box test scores (r = 0.795), significant difference of cDVA scores between those with and without pathology (p visual acuity when the head is still and moving, as well as a good proxy of vestibular function to yaw rotation.

  12. Dual function seal: visualized digital signature for electronic medical record systems.

    Science.gov (United States)

    Yu, Yao-Chang; Hou, Ting-Wei; Chiang, Tzu-Chiang

    2012-10-01

    Digital signature is an important cryptography technology to be used to provide integrity and non-repudiation in electronic medical record systems (EMRS) and it is required by law. However, digital signatures normally appear in forms unrecognizable to medical staff, this may reduce the trust from medical staff that is used to the handwritten signatures or seals. Therefore, in this paper we propose a dual function seal to extend user trust from a traditional seal to a digital signature. The proposed dual function seal is a prototype that combines the traditional seal and digital seal. With this prototype, medical personnel are not just can put a seal on paper but also generate a visualized digital signature for electronic medical records. Medical Personnel can then look at the visualized digital signature and directly know which medical personnel generated it, just like with a traditional seal. Discrete wavelet transform (DWT) is used as an image processing method to generate a visualized digital signature, and the peak signal to noise ratio (PSNR) is calculated to verify that distortions of all converted images are beyond human recognition, and the results of our converted images are from 70 dB to 80 dB. The signature recoverability is also tested in this proposed paper to ensure that the visualized digital signature is verifiable. A simulated EMRS is implemented to show how the visualized digital signature can be integrity into EMRS.

  13. The human visual cortex responds to gene therapy-mediated recovery of retinal function.

    Science.gov (United States)

    Ashtari, Manzar; Cyckowski, Laura L; Monroe, Justin F; Marshall, Kathleen A; Chung, Daniel C; Auricchio, Alberto; Simonelli, Francesca; Leroy, Bart P; Maguire, Albert M; Shindler, Kenneth S; Bennett, Jean

    2011-06-01

    Leber congenital amaurosis (LCA) is a rare degenerative eye disease, linked to mutations in at least 14 genes. A recent gene therapy trial in patients with LCA2, who have mutations in RPE65, demonstrated that subretinal injection of an adeno-associated virus (AAV) carrying the normal cDNA of that gene (AAV2-hRPE65v2) could markedly improve vision. However, it remains unclear how the visual cortex responds to recovery of retinal function after prolonged sensory deprivation. Here, 3 of the gene therapy trial subjects, treated at ages 8, 9, and 35 years, underwent functional MRI within 2 years of unilateral injection of AAV2-hRPE65v2. All subjects showed increased cortical activation in response to high- and medium-contrast stimuli after exposure to the treated compared with the untreated eye. Furthermore, we observed a correlation between the visual field maps and the distribution of cortical activations for the treated eyes. These data suggest that despite severe and long-term visual impairment, treated LCA2 patients have intact and responsive visual pathways. In addition, these data suggest that gene therapy resulted in not only sustained and improved visual ability, but also enhanced contrast sensitivity.

  14. Determination of hemispheric language dominance using functional MRI : comparison of visual and auditory stimuli

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Ic Ryung; Ahn, Kook Jin; Lee, Jae Mun [The Catholic Univ. of Korea, Seoul (Korea, Republic of); Kim, Tae [The Catholic Magnetic Resonance Research Center, Seoul (Korea, Republic of)

    1999-12-01

    To assess the difference between auditory and visual stimuli when determining hemispheric language dominance by using functional MRI. In ten healthy adult volunteers (8 right-handed, 1 left-handed, 1 ambidextrous), motor language activation in axial slices of frontal lobe was mapped on a Simens 1.5T Vision Plus system using single-shot EPI. Series of 120 consecutive images per section were acquired during three cycles of task activation and rest. During each activation, a series of four syllables was delivered by means of both a visual and auditory method, and the volunteers were asked to mentally generate words starting with each syllable. In both in ferior frontal gyri and whole frontal lobes, lateralization indices were calculated from the activated pixels. We determined the language dominant hemisphere, and compared the results of the visual method and the auditory method. Seven right-handed persons were left-hemisphere dominant, and one left-handed and one ambidex-trous person were right-hemisphere dominant. Five of nine persons demonstrated larger lateralization indices with the auditory method than the visual method, while the remaining four showed larger lateralization indices with the visual method. No statistically significant difference was noted when comparing the results of the two methods(p>0.05). When determining hemispheric language dominance using functional MRI, the two methods are equally appropriate.

  15. Early visual environment and development of visual function%早期视觉环境与视觉功能发育

    Institute of Scientific and Technical Information of China (English)

    蒋斌; 李硕; 张琴芬

    2013-01-01

    半个世纪以来,对哺乳动物视觉系统的研究阐明了视网膜-外膝体-视皮层之间复杂而有序的拓扑式神经连接以及视皮层功能的发育过程。视觉神经通路首先是基因遗传、分子及内在电生理活动调控的非视觉经验依赖性发育,然后是动物睁眼后视觉经验调控下的视觉皮层细胞感受野与方位柱、眼优势柱及双眼视觉等功能发育,因此视觉系统的发育是由遗传和环境共同来塑造。本文主要对哺乳动物出生后视觉通路发育过程特别是早期视觉环境对正常视觉功能发育的重要作用作一综述,并探讨通过改善视觉环境以治疗弱视患者的医疗可能性。%Over the past half-century,investigations on mammalian visual system have clarified that the visual pathway from retina to primary visual cortex is highly complex but displays the orderly topologi-cal neural connections.Furthermore,previous explorations especially revealed the function of primary visual cortex and its postnatal development.The development of visual pathway is orchestrated initially by an early innate non-visual experience-dependent regulated by successively genetic,molecules and inher-ent electrophysiological activity,and then visual functions in primary visual cortex such as receptive fields,orientation specific columns,cortical ocular dominance columns and binocular vision etc,are highly regulated by visual experience.Therefore,the development of the visual system is sculpted not on-ly by heredity but also by visual experience after eye opening.This review highlights the postnatal devel-opment of mammalian visual pathway,especially the important effects of early visual environment on the development of normal visual function,and discusses the medical possibilities of improving the treatment of amblyopia by visual environment.

  16. Functional analysis from visual and compositional data. An artificial intelligence approach.

    Science.gov (United States)

    Barceló, J. A.; Moitinho de Almeida, V.

    Why archaeological artefacts are the way they are? In this paper we try to solve such a question by investigating the relationship between form and function. We propose new ways of studying the way behaviour in the past can be asserted on the examination of archaeological observables in the present. In any case, we take into account that there are also non-visual features characterizing ancient objects and materials (i.e., compositional information based on mass spectrometry data, chronological information based on radioactive decay measurements, etc.). Information that should make us aware of many functional properties of objects is multidimensional in nature: size, which makes reference to height, length, depth, weight and mass; shape and form, which make reference to the geometry of contours and volumes; texture, which refers to the microtopography (roughness, waviness, and lay) and visual appearance (colour variations, brightness, reflectivity and transparency) of surfaces; and finally material, meaning the combining of distinct compositional elements and properties to form a whole. With the exception of material data, the other relevant aspects for functional reasoning have been traditionally described in rather ambiguous terms, without taking into account the advantages of quantitative measurements of shape/form, and texture. Reasoning about the functionality of archaeological objects recovered at the archaeological site requires a cross-disciplinary investigation, which may also range from recognition techniques used in computer vision and robotics to reasoning, representation, and learning methods in artificial intelligence. The approach we adopt here is to follow current computational theories of object perception to ameliorate the way archaeology can deal with the explanation of human behaviour in the past (function) from the analysis of visual and non-visual data, taking into account that visual appearances and even compositional characteristics only

  17. Activity Limitation in Glaucoma: Objective Assessment by the Cambridge Glaucoma Visual Function Test.

    Science.gov (United States)

    Skalicky, Simon E; McAlinden, Colm; Khatib, Tasneem; Anthony, Louise May; Sim, Sing Yue; Martin, Keith R; Goldberg, Ivan; McCluskey, Peter

    2016-11-01

    We design and evaluate a computer-based objective simulation of activity limitation related to glaucoma. A cross-sectional study was performed involving 70 glaucoma patients and 14 controls. Mean age was 69.0 ± 10.2 years; 49 (58.3%) were male. The Cambridge Glaucoma Visual Function Test (CGVFT) was administered to all participants. Rasch analysis and criterion, convergent, and divergent validity tests assessed the psychometric properties of the CGVFT. Regression modeling was used to determine factors predictive of CGVFT person measures. Sociodemographic information, better and worse eye visual field parameters, visual acuity, contrast sensitivity, and the Rasch-analyzed Glaucoma Activity Limitation-9 (GAL-9) and Visual Function Questionnaire Utility Index (VFQUI) questionnaire responses were recorded. From 139 pilot CGVFT items, 59 had acceptable fit to the Rasch model, with acceptable precision (person separation index, 2.13) and targeting. Cambridge Glaucoma Visual Function Test person measure (logit) scores increased between controls (-0.20 ± 0.08) and patients with mild (-0.15 ± 0.08), moderate (-0.13 ± 0.10), and severe (-0.05 ± 0.10) glaucoma (P < 0.001, ANOVA) indicating good criterion validity. Correlation coefficients of 0.455 (P < 0.001) between CGVFT and GAL-9 person measures and 0.399 (P = 0.005) between CGVFT and VFQUI person measures demonstrated convergent validity. Divergent validity was suboptimal. On multivariable analysis, lower better eye mean deviation and greater age were associated with worsening CGVFT person measures (P ≤ 0.001). The CGVFT is a computerized visual challenge test administered to a cohort of glaucoma patients. It may benefit glaucoma patients, careers, health care providers, and policy makers, providing increased awareness of activity limitation due to glaucoma.

  18. Brain functional network connectivity based on a visual task: visual information processing-related brain regions are significantly activated in the task state.

    Science.gov (United States)

    Yang, Yan-Li; Deng, Hong-Xia; Xing, Gui-Yang; Xia, Xiao-Luan; Li, Hai-Fang

    2015-02-01

    It is not clear whether the method used in functional brain-network related research can be applied to explore the feature binding mechanism of visual perception. In this study, we investigated feature binding of color and shape in visual perception. Functional magnetic resonance imaging data were collected from 38 healthy volunteers at rest and while performing a visual perception task to construct brain networks active during resting and task states. Results showed that brain regions involved in visual information processing were obviously activated during the task. The components were partitioned using a greedy algorithm, indicating the visual network existed during the resting state. Z-values in the vision-related brain regions were calculated, confirming the dynamic balance of the brain network. Connectivity between brain regions was determined, and the result showed that occipital and lingual gyri were stable brain regions in the visual system network, the parietal lobe played a very important role in the binding process of color features and shape features, and the fusiform and inferior temporal gyri were crucial for processing color and shape information. Experimental findings indicate that understanding visual feature binding and cognitive processes will help establish computational models of vision, improve image recognition technology, and provide a new theoretical mechanism for feature binding in visual perception.

  19. Brain functional network connectivity based on a visual task:visual information processing-related brain regions are signiifcantly activated in the task state

    Institute of Scientific and Technical Information of China (English)

    Yan-li Yang; Hong-xia Deng; Gui-yang Xing; Xiao-luan Xia; Hai-fang Li

    2015-01-01

    It is not clear whether the method used in functional brain-network related research can be applied to explore the feature binding mechanism of visual perception. In this study, we inves-tigated feature binding of color and shape in visual perception. Functional magnetic resonance imaging data were collected from 38 healthy volunteers at rest and while performing a visual perception task to construct brain networks active during resting and task states. Results showed that brain regions involved in visual information processing were obviously activated during the task. The components were partitioned using a greedy algorithm, indicating the visual network existed during the resting state.Z-values in the vision-related brain regions were calculated, conifrming the dynamic balance of the brain network. Connectivity between brain regions was determined, and the result showed that occipital and lingual gyri were stable brain regions in the visual system network, the parietal lobe played a very important role in the binding process of color features and shape features, and the fusiform and inferior temporal gyri were crucial for processing color and shape information. Experimental ifndings indicate that understanding visual feature binding and cognitive processes will help establish computational models of vision, improve image recognition technology, and provide a new theoretical mechanism for feature binding in visual perception.

  20. Brain functional network connectivity based on a visual task: visual information processing-related brain regions are significantly activated in the task state

    Directory of Open Access Journals (Sweden)

    Yan-li Yang

    2015-01-01

    Full Text Available It is not clear whether the method used in functional brain-network related research can be applied to explore the feature binding mechanism of visual perception. In this study, we investigated feature binding of color and shape in visual perception. Functional magnetic resonance imaging data were collected from 38 healthy volunteers at rest and while performing a visual perception task to construct brain networks active during resting and task states. Results showed that brain regions involved in visual information processing were obviously activated during the task. The components were partitioned using a greedy algorithm, indicating the visual network existed during the resting state. Z-values in the vision-related brain regions were calculated, confirming the dynamic balance of the brain network. Connectivity between brain regions was determined, and the result showed that occipital and lingual gyri were stable brain regions in the visual system network, the parietal lobe played a very important role in the binding process of color features and shape features, and the fusiform and inferior temporal gyri were crucial for processing color and shape information. Experimental findings indicate that understanding visual feature binding and cognitive processes will help establish computational models of vision, improve image recognition technology, and provide a new theoretical mechanism for feature binding in visual perception.

  1. Impact of First Eye versus Second Eye Cataract Surgery on Visual Function and Quality of Life.

    Science.gov (United States)

    Shekhawat, Nakul S; Stock, Michael V; Baze, Elizabeth F; Daly, Mary K; Vollman, David E; Lawrence, Mary G; Chomsky, Amy S

    2017-05-16

    To compare the impact of first eye versus second eye cataract surgery on visual function and quality of life. Cohort study. A total of 328 patients undergoing separate first eye and second eye phacoemulsification cataract surgeries at 5 veterans affairs centers in the United States. Patients with previous ocular surgery, postoperative endophthalmitis, postoperative retinal detachment, reoperation within 30 days, dementia, anxiety disorder, hearing difficulty, or history of drug abuse were excluded. Patients received complete preoperative and postoperative ophthalmic examinations for first eye and second eye cataract surgeries. Best-corrected visual acuity (BCVA) was measured 30 to 90 days preoperatively and postoperatively. Patients completed the National Eye Institute Visual Functioning Questionnaire (NEI-VFQ) 30 to 90 days preoperatively and postoperatively. The NEI-VFQ scores were calculated using a traditional subscale scoring algorithm and a Rasch-refined approach producing visual function and socioemotional subscale scores. Postoperative NEI-VFQ scores and improvement in NEI-VFQ scores comparing first eye versus second eye cataract surgery. Mean age was 70.4 years (±9.6 standard deviation [SD]). Compared with second eyes, first eyes had worse mean preoperative BCVA (0.55 vs. 0.36 logarithm of the minimum angle of resolution (logMAR), P < 0.001), greater mean BCVA improvement after surgery (-0.50 vs. -0.32 logMAR, P < 0.001), and slightly worse postoperative BCVA (0.06 vs. 0.03 logMAR, P = 0.039). Compared with first eye surgery, second eye surgery resulted in higher postoperative NEI-VFQ scores for nearly all traditional subscales (P < 0.001), visual function subscale (-3.85 vs. -2.91 logits, P < 0.001), and socioemotional subscale (-2.63 vs. -2.10 logits, P < 0.001). First eye surgery improved visual function scores more than second eye surgery (-2.99 vs. -2.67 logits, P = 0.021), but both first and second eye surgeries resulted in similar

  2. The Relationship Between Vision-related Quality of Life and Visual Function in Glaucoma Patients

    OpenAIRE

    Hirooka, Kazuyuki; Sato, Shino; Nitta, Eri; Tsujikawa, Akitaka

    2016-01-01

    Purpose: To evaluate the relationship between vision-related quality of life (QOL) as measured by the short-form 11-item Japanese version of the Visual Function Questionnaire (VFQ-J11) and the severity of visual field (VF) defects in patients with glaucoma. Methods: The study included 134 glaucoma patients and 30 normal subjects. VF testing using the Humphrey Field Analyzer was performed to obtain both the VF index (VFI) and MD in both eyes of each glaucoma patient. Binocular integrated VF wa...

  3. Task-related Functional Connectivity Dynamics in a Block-designed Visual Experiment

    Directory of Open Access Journals (Sweden)

    Xin eDi

    2015-09-01

    Full Text Available Studying task modulations of brain connectivity using functional magnetic resonance imaging (fMRI is critical to understand brain functions that support cognitive and affective processes. Existing methods such as psychophysiological interaction (PPI and dynamic causal modelling (DCM usually implicitly assume that the connectivity patterns are stable over a block-designed task with identical stimuli. However, this assumption lacks empirical verification on high-temporal resolution fMRI data with reliable data-driven analysis methods. The present study performed a detailed examination of dynamic changes of functional connectivity (FC in a simple block-designed visual checkerboard experiment with a sub-second sampling rate (TR = 0.645 s by estimating time-varying correlation coefficient (TVCC between BOLD responses of different brain regions. We observed reliable task-related FC changes (i.e., FCs were transiently decreased after task onset and went back to the baseline afterward among several visual regions of the bilateral middle occipital gyrus (MOG and the bilateral fusiform gyrus (FuG. Importantly, only the FCs between higher visual regions (MOG and lower visual regions (FuG exhibited such dynamic patterns. The results suggested that simply assuming a sustained FC during a task block may be insufficient to capture distinct task-related FC changes. The investigation of FC dynamics in tasks could improve our understanding of condition shifts and the coordination between different activated brain regions.

  4. Early development in Dravet syndrome; visual function impairment precedes cognitive decline.

    Science.gov (United States)

    Chieffo, Daniela; Ricci, Daniela; Baranello, Giovanni; Martinelli, Diego; Veredice, Chiara; Lettori, Donatella; Battaglia, Domenica; Dravet, Charlotte; Mercuri, Eugenio; Guzzetta, Francesco

    2011-01-01

    Aim of the study was to describe prospectively the early neuropsychological evolution including the first pre-cognitive stages of the Severe Myoclonic Epilepsy in Infancy (SMEI) or Dravet syndrome. Five cases, four of whom since before a diagnostic evidence of the Dravet syndrome, were followed up. Full clinical assessment including developmental, visual function and behaviour assessments were serially performed. In four cases, a variable onset age of cognitive decline assessed with developmental scales was preceded some months before by an impairment of visual function; the remaining patient during all the course of follow-up till 51 months of age showed a normal development without visual impairment. A cognitive decline with variable onset was generally confirmed in Dravet syndrome. The previous early impairment of visual function seems to herald the cognitive decline and provides useful prognostic information; furthermore, it possibly suggests some clues for a better understanding of the mechanisms of cognitive deterioration in this syndrome. 2010 Elsevier B.V. All rights reserved.

  5. A functional and perceptual signature of the second visual area in primates.

    Science.gov (United States)

    Freeman, Jeremy; Ziemba, Corey M; Heeger, David J; Simoncelli, Eero P; Movshon, J Anthony

    2013-07-01

    There is no generally accepted account of the function of the second visual cortical area (V2), partly because no simple response properties robustly distinguish V2 neurons from those in primary visual cortex (V1). We constructed synthetic stimuli replicating the higher-order statistical dependencies found in natural texture images and used them to stimulate macaque V1 and V2 neurons. Most V2 cells responded more vigorously to these textures than to control stimuli lacking naturalistic structure; V1 cells did not. Functional magnetic resonance imaging (fMRI) measurements in humans revealed differences between V1 and V2 that paralleled the neuronal measurements. The ability of human observers to detect naturalistic structure in different types of texture was well predicted by the strength of neuronal and fMRI responses in V2 but not in V1. Together, these results reveal a particular functional role for V2 in the representation of natural image structure.

  6. Personal experience with narrated events modulates functional connectivity within visual and motor systems during story comprehension.

    Science.gov (United States)

    Chow, Ho Ming; Mar, Raymond A; Xu, Yisheng; Liu, Siyuan; Wagage, Suraji; Braun, Allen R

    2015-04-01

    Past experience of everyday life activities, which forms the basis of our knowledge about the world, greatly affects how we understand stories. Yet, little is known about how this influence is instantiated in the human brain. Here, we used functional magnetic resonance imaging to investigate how past experience facilitates functional connectivity during the comprehension of stories rich in perceptual and motor details. We found that comprehenders' past experience with the scenes and actions described in the narratives selectively modulated functional connectivity between lower- and higher-level areas within the neural systems for visual and motor processing, respectively. These intramodal interactions may play an important role in integrating personal knowledge about a narrated situation with an evolving discourse representation. This study provides empirical evidence consistent with the idea that regions related to visual and motor processing are involved in the reenactment of experience as proposed by theories of embodied cognition.

  7. Improvements in clinical and functional vision and perceived visual disability after first and second eye cataract surgery

    OpenAIRE

    Elliott, D; Patla, A.; Bullimore, M.

    1997-01-01

    AIMS—To determine the improvements in clinical and functional vision and perceived visual disability after first and second eye cataract surgery.
METHODS—Clinical vision (monocular and binocular high and low contrast visual acuity, contrast sensitivity, and disability glare), functional vision (face identity and expression recognition, reading speed, word acuity, and mobility orientation), and perceived visual disability (Activities of Daily Vision Scale) were measured in 25 subjects before a...

  8. Motion sickness increases functional connectivity between visual motion and nausea-associated brain regions.

    Science.gov (United States)

    Toschi, Nicola; Kim, Jieun; Sclocco, Roberta; Duggento, Andrea; Barbieri, Riccardo; Kuo, Braden; Napadow, Vitaly

    2017-01-01

    The brain networks supporting nausea not yet understood. We previously found that while visual stimulation activated primary (V1) and extrastriate visual cortices (MT+/V5, coding for visual motion), increasing nausea was associated with increasing sustained activation in several brain areas, with significant co-activation for anterior insula (aIns) and mid-cingulate (MCC) cortices. Here, we hypothesized that motion sickness also alters functional connectivity between visual motion and previously identified nausea-processing brain regions. Subjects prone to motion sickness and controls completed a motion sickness provocation task during fMRI/ECG acquisition. We studied changes in connectivity between visual processing areas activated by the stimulus (MT+/V5, V1), right aIns and MCC when comparing rest (BASELINE) to peak nausea state (NAUSEA). Compared to BASELINE, NAUSEA reduced connectivity between right and left V1 and increased connectivity between right MT+/V5 and aIns and between left MT+/V5 and MCC. Additionally, the change in MT+/V5 to insula connectivity was significantly associated with a change in sympathovagal balance, assessed by heart rate variability analysis. No state-related connectivity changes were noted for the control group. Increased connectivity between a visual motion processing region and nausea/salience brain regions may reflect increased transfer of visual/vestibular mismatch information to brain regions supporting nausea perception and autonomic processing. We conclude that vection-induced nausea increases connectivity between nausea-processing regions and those activated by the nauseogenic stimulus. This enhanced low-frequency coupling may support continual, slowly evolving nausea perception and shifts toward sympathetic dominance. Disengaging this coupling may be a target for biobehavioral interventions aimed at reducing motion sickness severity. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. A Case of Functional (Psychogenic Monocular Hemianopia Analyzed by Measurement of Hemifield Visual Evoked Potentials

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Yoneda

    2013-12-01

    Full Text Available Purpose: Functional monocular hemianopia is an extremely rare condition, for which measurement of hemifield visual evoked potentials (VEPs has not been previously described. Methods: A 14-year-old boy with functional monocular hemianopia was followed up with Goldmann perimetry and measurement of hemifield and full-field VEPs. Results: The patient had a history of monocular temporal hemianopia of the right eye following headache, nausea and ague. There was no relative afferent pupillary defect, and a color perception test was normal. Goldmann perimetry revealed a vertical monocular temporal hemianopia of the right eye; the hemianopia on the right was also detected with a binocular visual field test. Computed tomography, magnetic resonance imaging (MRI and MR angiography of the brain including the optic chiasm as well as orbital MRI revealed no abnormalities. On the basis of these results, we diagnosed the patient's condition as functional monocular hemianopia. Pattern VEPs according to the International Society for Clinical Electrophysiology of Vision (ISCEV standard were within the normal range. The hemifield pattern VEPs for the right eye showed a symmetrical latency and amplitude for nasal and temporal hemifield stimulation. One month later, the visual field defect of the patient spontaneously disappeared. Conclusions: The latency and amplitude of hemifield VEPs for a patient with functional monocular hemianopia were normal. Measurement of hemifield VEPs may thus provide an objective tool for distinguishing functional hemianopia from hemifield loss caused by an organic lesion.

  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. Visual acuity and retinal function in patients with Bardet-Biedl syndrome

    Directory of Open Access Journals (Sweden)

    Adriana Berezovsky

    2012-01-01

    Full Text Available OBJECTIVE: Bardet-Biedl syndrome is a genetic, multisystem disorder that causes severe visual impairment. This condition is characterized by retinal dystrophy, obesity, digit anomalies, renal disease, and hypogonadism. The purpose of this study was to analyze visual acuity and full-field electroretinogram findings in patients with the Bardet-Biedl syndrome phenotype. METHODS: The visual acuity of a group of 23 patients (15 males with ages ranging from 6-36 years (mean = 15.8±6.4; median = 14.7 was assessed. Retinal function was evaluated by full-field electroretinography, and dark-adapted thresholds were assessed. RESULTS: Visual acuity in the better-seeing eye was 20/40 or better in 5 patients (21.7%, 20/50-20/150 in 13 (56.5% patients, 20/200-20/400 in 2 (8.7% patients and worse than 20/400 in one (4.3% patient. The mean acuity in the better-seeing eye was 0.7±0.6 logMAR (20/100, Snellen equivalent. Scotopic rod and maximal responses were nondetectable in 21 (91.3% patients, and cone responses were non-detectable in 15 (65.2% patients. Elevated darkadapted visual thresholds were observed in all 19 patients who were able to be assessed, with 10 (52.6% patients having thresholds greater than 30 dB. CONCLUSIONS: In a relatively young cohort of patients with Bardet-Biedl syndrome, only 21% had 20/40 or better vision. ERG scotopic responses were absent in the majority of cases, with cone responses being observed in less than half of cases. These findings showed the early deleterious effects in retinal function and visual acuity caused by this condition.

  12. A Computational Analysis of the Function of Three Inhibitory Cell Types in Contextual Visual Processing

    Directory of Open Access Journals (Sweden)

    Jung H. Lee

    2017-04-01

    Full Text Available Most cortical inhibitory cell types exclusively express one of three genes, parvalbumin, somatostatin and 5HT3a. We conjecture that these three inhibitory neuron types possess distinct roles in visual contextual processing based on two observations. First, they have distinctive synaptic sources and targets over different spatial extents and from different areas. Second, the visual responses of cortical neurons are affected not only by local cues, but also by visual context. We use modeling to relate structural information to function in primary visual cortex (V1 of the mouse, and investigate their role in contextual visual processing. Our findings are three-fold. First, the inhibition mediated by parvalbumin positive (PV cells mediates local processing and could underlie their role in boundary detection. Second, the inhibition mediated by somatostatin-positive (SST cells facilitates longer range spatial competition among receptive fields. Third, non-specific top-down modulation to interneurons expressing vasoactive intestinal polypeptide (VIP, a subclass of 5HT3a neurons, can selectively enhance V1 responses.

  13. TVA-based assessment of visual attentional functions in developmental dyslexia

    Directory of Open Access Journals (Sweden)

    Johanna eBogon

    2014-10-01

    Full Text Available There is an ongoing debate whether an impairment of visual attentional functions constitutes an additional or even an isolated deficit of developmental dyslexia (DD. Especially performance in tasks that require the processing of multiple visual elements in parallel has been reported to be impaired in DD. We review studies that used parameter-based assessment for identifying and quantifying impaired aspect(s of visual attention that underlie this multi-element-processing deficit in DD. These studies used the mathematical framework provided by the ‘theory of visual attention’ (TVA; Bundesen, 1990 to derive quantitative measures of general attentional resources and attentional weighting aspects on the basis of behavioral performance in whole- and partial-report tasks. Based on parameter estimates in children and adults with DD, the reviewed studies support a slowed perceptual processing speed as an underlying primary deficit in DD. Moreover, a reduction in visual short term memory storage capacity seems to present a modulating component, contributing to difficulties in written language processing. Furthermore, comparing the spatial distributions of attentional weights in children and adults suggest that having limited reading and writing skills might impair the development of a slight leftward bias, that is typical for unimpaired adult readers.

  14. Supplementary Material for: A Geometric Approach to Visualization of Variability in Functional Data

    KAUST Repository

    Xie, Weiyi

    2016-01-01

    We propose a new method for the construction and visualization of boxplot-type displays for functional data. We use a recent functional data analysis framework, based on a representation of functions called square-root slope functions, to decompose observed variation in functional data into three main components: amplitude, phase, and vertical translation. We then construct separate displays for each component, using the geometry and metric of each representation space, based on a novel definition of the median, the two quartiles, and extreme observations. The outlyingness of functional data is a very complex concept. Thus, we propose to identify outliers based on any of the three main components after decomposition. We provide a variety of visualization tools for the proposed boxplot-type displays including surface plots. We evaluate the proposed method using extensive simulations and then focus our attention on three real data applications including exploratory data analysis of sea surface temperature functions, electrocardiogram functions and growth curves.

  15. "Visual"时代Windows API函数的使用%Application of Windows API Function in Visual Times

    Institute of Scientific and Technical Information of China (English)

    杨平; 李建武; 李茗

    2004-01-01

    在"Visual"时代,Windows API函数是进入操作系统核心进行高级编程的重要工具.本文介绍了Windows API函数概念,通过示例分析如何在Visual Basic、Delphi、Visual C++等语言中使用Windows API函数对操作系统核心进行编程.

  16. Functional divisions for visual processing in the central brain of flying Drosophila.

    Science.gov (United States)

    Weir, Peter T; Dickinson, Michael H

    2015-10-06

    Although anatomy is often the first step in assigning functions to neural structures, it is not always clear whether architecturally distinct regions of the brain correspond to operational units. Whereas neuroarchitecture remains relatively static, functional connectivity may change almost instantaneously according to behavioral context. We imaged panneuronal responses to visual stimuli in a highly conserved central brain region in the fruit fly, Drosophila, during flight. In one substructure, the fan-shaped body, automated analysis revealed three layers that were unresponsive in quiescent flies but became responsive to visual stimuli when the animal was flying. The responses of these regions to a broad suite of visual stimuli suggest that they are involved in the regulation of flight heading. To identify the cell types that underlie these responses, we imaged activity in sets of genetically defined neurons with arborizations in the targeted layers. The responses of this collection during flight also segregated into three sets, confirming the existence of three layers, and they collectively accounted for the panneuronal activity. Our results provide an atlas of flight-gated visual responses in a central brain circuit.

  17. I finally see what you see: Parkinson's disease visual hallucinations captured with functional neuroimaging.

    Science.gov (United States)

    Goetz, Christopher G; Vaughan, Christina L; Goldman, Jennifer G; Stebbins, Glenn T

    2014-01-01

    Functional neuroimaging studies have described alterations in neural activation in PD patients with chronic hallucinations. These studies have not, however, captured neural activation patterns during an actual hallucinatory event. The objective of this work was to investigate neuroanatomical substrates active during visual hallucinations in a patient with Parkinson's disease (PD). We conducted an event-related functional magnetic resonance imaging (fMRI) case-study examination of a 66-year-old male PD patient with stereotypic, chronic, and frequent visual hallucinations. The patient reported 16 hallucinations during the fMRI scan. Increased activation during hallucinations was found in the cingulate, insula, frontal lobe, thalamus, and brain stem. Decreased activation was found in the lingual and fusiform gyri, inferior occipital gyrus, and middle frontal and superior temporal lobes. To our knowledge, this report is the first published case documenting the cortical activation patterns using fMRI techniques in a PD patient during active hallucinations. Our results suggest that during a visual hallucination, a marked desynchronization occurs between posterior and anterior cortical areas involved in visual processing. Copyright © 2013 Movement Disorder Society.

  18. Exploring visual attention functions of the human extrageniculate pathways through behavioral cues.

    Science.gov (United States)

    Mizzi, Raphaël; Michael, George A

    2016-11-01

    Over the past few decades, evidence has accumulated showing that, at subcortical levels, visual attention depends partly on the extrageniculate neural pathways, that is, those pathways that bypass the lateral geniculate nucleus and circumvent the primary visual cortex. Working in concert with neuroscience, experimental psychology has contributed considerably to the understanding of the role these pathways play through the use of 3 behavioral cues: nasal-temporal asymmetries, responses to S-cone stimuli, and responses to perceptually suppressed stimuli. In this article, after presenting the extrageniculate pathways and the role of each of the component structures in visual attention, we review findings from studies that have used these behavioral cues, as well as what they tell us about the role of the extrageniculate pathways in visual attention. We conclude that nasal-temporal asymmetries and responses to S-cone stimuli are plausible probes of extrageniculate functions, because they are consistent with neurophysiological, neuropsychological, and neuroimaging findings. By contrast, despite promising perspectives, the literature is yet too scarce for responses to perceptually suppressed stimuli to be considered as a plausible probe of extrageniculate-dependent attention functions. (PsycINFO Database Record

  19. Circadian perinatal photoperiod has enduring effects on retinal dopamine and visual function.

    Science.gov (United States)

    Jackson, Chad R; Capozzi, Megan; Dai, Heng; McMahon, Douglas G

    2014-03-26

    Visual system development depends on neural activity, driven by intrinsic and light-sensitive mechanisms. Here, we examined the effects on retinal function due to exposure to summer- and winter-like circadian light cycles during development and adulthood. Retinal light responses, visual behaviors, dopamine content, retinal morphology, and gene expression were assessed in mice reared in seasonal photoperiods consisting of light/dark cycles of 8:16, 16:8, and 12:12 h, respectively. Mice exposed to short, winter-like, light cycles showed enduring deficits in photopic retinal light responses and visual contrast sensitivity, but only transient changes were observed for scotopic measures. Dopamine levels were significantly lower in short photoperiod mice, and dopaminergic agonist treatment rescued the photopic light response deficits. Tyrosine hydroxylase and Early Growth Response factor-1 mRNA expression were reduced in short photoperiod retinas. Therefore, seasonal light cycles experienced during retinal development and maturation have lasting influence on retinal and visual function, likely through developmental programming of retinal dopamine.

  20. [Impairment of safety in navigation caused by alcohol: impact on visual function].

    Science.gov (United States)

    Grütters, G; Reichelt, J A; Ritz-Timme, S; Thome, M; Kaatsch, H J

    2003-05-01

    So far in Germany, no legally binding standards for blood alcohol concentration exist that prove an impairment of navigability. The aim of our interdisciplinary project was to obtain data in order to identify critical blood alcohol limits. In this context the visual system seems to be of decisive importance. 21 professional skippers underwent realistic navigational demands soberly and alcoholized in a sea traffic simulator. The following parameters were considered: visual acuity, stereopsis, color vision, and accommodation. Under the influence of alcohol (average blood alcohol concentration: 1.08 per thousand ) each skipper considered himself to be completely capable of navigating. While simulations were running, all of the skippers made nautical mistakes or underestimated dangerous situations. Severe impairment in visual acuity or binocular function were not observed. Accommodation decreased by an average of 18% ( p=0.0001). In the test of color vision skippers made more mistakes ( p=0.017) and the time needed for this test was prolonged ( p=0.004). Changes in visual function as well as vegetative and psychological reactions could be the cause of mistakes and alcohol should therefore be regarded as a severe risk factor for security in sea navigation.

  1. Functional divisions for visual processing in the central brain of flying Drosophila

    Science.gov (United States)

    Weir, Peter T.; Dickinson, Michael H.

    2015-01-01

    Although anatomy is often the first step in assigning functions to neural structures, it is not always clear whether architecturally distinct regions of the brain correspond to operational units. Whereas neuroarchitecture remains relatively static, functional connectivity may change almost instantaneously according to behavioral context. We imaged panneuronal responses to visual stimuli in a highly conserved central brain region in the fruit fly, Drosophila, during flight. In one substructure, the fan-shaped body, automated analysis revealed three layers that were unresponsive in quiescent flies but became responsive to visual stimuli when the animal was flying. The responses of these regions to a broad suite of visual stimuli suggest that they are involved in the regulation of flight heading. To identify the cell types that underlie these responses, we imaged activity in sets of genetically defined neurons with arborizations in the targeted layers. The responses of this collection during flight also segregated into three sets, confirming the existence of three layers, and they collectively accounted for the panneuronal activity. Our results provide an atlas of flight-gated visual responses in a central brain circuit. PMID:26324910

  2. Accidental bilateral Q-switched neodymium laser exposure: treatment and recovery of visual function

    Science.gov (United States)

    Zwick, Harry; Stuck, Bruce E.; Dunlap, Weldon; Scales, David K.; Lund, David J.; Ness, James W.

    1998-05-01

    A 21 year old female was accidentally exposed in both eyes when she looked into the 10 cm exit aperture of a military laser designator emitting 1064 nm q-switched (30 ns) pulses at a 10 pulse per second rate. Steroid therapy (methylprednisolone sodium succinate) was initiated within 6 hours post exposure. Initial ophthalmoscopic observation revealed small contained macular hemorrhages in each eye. Fluorescein angiography (FA) showed minimal leakage. Visual acuity was 20/100 and 20/60 in OD and OS respectively. Contrast sensitivity in both eyes was depressed across all spatial frequencies by more than 1.5 log units. At four weeks post exposure, no significant macular scarring was apparent and visual acuity returned to 20/25 in both eyes. Contrast sensitivity had improved to normal levels with a peak at 3 cycles/degree. At one year post exposure, visual acuity was 20/13 in both eyes and measures of contrast sensitivity were within normal limits. During the course of recovery, the patient's fixation shifted from a slightly superior temporal site back to the central foveal region. The foveal lesion sites were still evident by ophthalmoscopy and Amsler grid measurements but were deemed functional when the patient placed small targets generated by the scanning laser ophthalmoscope in the lesion site for discrimination. This outcome indicates remarkable recovery of visual function and suggests that early administration of steroids may assist in preserving the natural neural recovery process of the photoreceptor matrix by minimizing intraretinal scar formation.

  3. Extra-visual functional and structural connection abnormalities in Leber's hereditary optic neuropathy.

    Science.gov (United States)

    Rocca, Maria A; Valsasina, Paola; Pagani, Elisabetta; Bianchi-Marzoli, Stefania; Milesi, Jacopo; Falini, Andrea; Comi, Giancarlo; Filippi, Massimo

    2011-02-10

    We assessed abnormalities within the principal brain resting state networks (RSNs) in patients with Leber's hereditary optic neuropathy (LHON) to define whether functional abnormalities in this disease are limited to the visual system or, conversely, tend to be more diffuse. We also defined the structural substrates of fMRI changes using a connectivity-based analysis of diffusion tensor (DT) MRI data. Neuro-ophthalmologic assessment, DT MRI and RS fMRI data were acquired from 13 LHON patients and 13 healthy controls. RS fMRI data were analyzed using independent component analysis and SPM5. A DT MRI connectivity-based parcellation analysis was performed using the primary visual and auditory cortices, bilaterally, as seed regions. Compared to controls, LHON patients had a significant increase of RS fluctuations in the primary visual and auditory cortices, bilaterally. They also showed decreased RS fluctuations in the right lateral occipital cortex and right temporal occipital fusiform cortex. Abnormalities of RS fluctuations were correlated significantly with retinal damage and disease duration. The DT MRI connectivity-based parcellation identified a higher number of clusters in the right auditory cortex in LHON vs. controls. Differences of cluster-centroid profiles were found between the two groups for all the four seeds analyzed. For three of these areas, a correspondence was found between abnormalities of functional and structural connectivities. These results suggest that functional and structural abnormalities extend beyond the visual network in LHON patients. Such abnormalities also involve the auditory network, thus corroborating the notion of a cross-modal plasticity between these sensory modalities in patients with severe visual deficits.

  4. Extra-visual functional and structural connection abnormalities in Leber's hereditary optic neuropathy.

    Directory of Open Access Journals (Sweden)

    Maria A Rocca

    Full Text Available We assessed abnormalities within the principal brain resting state networks (RSNs in patients with Leber's hereditary optic neuropathy (LHON to define whether functional abnormalities in this disease are limited to the visual system or, conversely, tend to be more diffuse. We also defined the structural substrates of fMRI changes using a connectivity-based analysis of diffusion tensor (DT MRI data. Neuro-ophthalmologic assessment, DT MRI and RS fMRI data were acquired from 13 LHON patients and 13 healthy controls. RS fMRI data were analyzed using independent component analysis and SPM5. A DT MRI connectivity-based parcellation analysis was performed using the primary visual and auditory cortices, bilaterally, as seed regions. Compared to controls, LHON patients had a significant increase of RS fluctuations in the primary visual and auditory cortices, bilaterally. They also showed decreased RS fluctuations in the right lateral occipital cortex and right temporal occipital fusiform cortex. Abnormalities of RS fluctuations were correlated significantly with retinal damage and disease duration. The DT MRI connectivity-based parcellation identified a higher number of clusters in the right auditory cortex in LHON vs. controls. Differences of cluster-centroid profiles were found between the two groups for all the four seeds analyzed. For three of these areas, a correspondence was found between abnormalities of functional and structural connectivities. These results suggest that functional and structural abnormalities extend beyond the visual network in LHON patients. Such abnormalities also involve the auditory network, thus corroborating the notion of a cross-modal plasticity between these sensory modalities in patients with severe visual deficits.

  5. Analysis of the Relationship Between Training Experience and Visual Sensory Functions in Athletes from Different Sports

    Directory of Open Access Journals (Sweden)

    Lesiakowski Piotr

    2017-06-01

    Full Text Available Introduction. Gaining insight into the mechanisms and scope of possible adaptations of visual functions to the conditions determined by the demands imposed by sports training seems to be very interesting not only from a cognitive point of view, but also with respect to the practical applications of the findings of such investigations in the training process. The aim of the study was to assess the function of early visual processing in athletes representing different sports disciplines with varying training experience. Material and methods. The study involved 95 athletes practising football (n = 24, volleyball (n = 22, boxing (n = 26, and rowing (n = 23. The bioelectric function of the visual pathway was assessed based on recordings of visual evoked potentials (VEPs. The regions which were stimulated were the peripheral and central areas of the retina. During the test, we recorded the amplitude (μV and latency (ms of the P100 component of the VEP waveform for both monocular stimulation (for the dominant and non-dominant eye and binocular stimulation. Results. Lower VEP P100 amplitude values were found for the peripheral and central locations for monocular and binocular viewing in more experienced volleyball players and rowers (p 0.05 in intragroup variability in VEP P100 latency in relation to training experience in any of the sports disciplines examined. Conclusions. Training experience has an influence on the early stage of sensory processing with respect to neural activity. Training experience has been found to differentiate athletes in terms of the temporal parameters of the visual evoked potentials recorded in the current study only to a limited extent.

  6. The influence of visual impairment on separate indicators of a functional condition of touch systems of pupils of middle classes

    Directory of Open Access Journals (Sweden)

    Lydmyla Shesterova

    2015-08-01

    Full Text Available Purpose: to define and to compare separate indicators of a functional condition of touch systems of pupils of middle classes with visual impairment and their contemporaries with normal vision. Materials and Methods: pupils of middle classes with visual impairment and pupils of middle classes with normal vision took part in the research. During the research such methods were applied: analysis and synthesis of references, perimetry, determination of visual acuity by means of a special table, acumetry, esthesiometry, determination of resistance of a vestibular mechanism to rotary loadings, methods of mathematical statistics. Results: the analysis of separate indicators of a functional condition of visual, acoustical, vestibular and tactile analyzers of pupils with visual impairment and without them is carried out. Conclusions: it is established that the studied indicators of a functional condition of touch systems at pupils of middle classes with visual impairment are better, than at their contemporaries with normal vision

  7. Detecting Glaucoma With a Portable Brain-Computer Interface for Objective Assessment of Visual Function Loss.

    Science.gov (United States)

    Nakanishi, Masaki; Wang, Yu-Te; Jung, Tzyy-Ping; Zao, John K; Chien, Yu-Yi; Diniz-Filho, Alberto; Daga, Fabio B; Lin, Yuan-Pin; Wang, Yijun; Medeiros, Felipe A

    2017-06-01

    The current assessment of visual field loss in diseases such as glaucoma is affected by the subjectivity of patient responses and the lack of portability of standard perimeters. To describe the development and initial validation of a portable brain-computer interface (BCI) for objectively assessing visual function loss. This case-control study involved 62 eyes of 33 patients with glaucoma and 30 eyes of 17 healthy participants. Glaucoma was diagnosed based on a masked grading of optic disc stereophotographs. All participants underwent testing with a BCI device and standard automated perimetry (SAP) within 3 months. The BCI device integrates wearable, wireless, dry electroencephalogram and electrooculogram systems and a cellphone-based head-mounted display to enable the detection of multifocal steady state visual-evoked potentials associated with visual field stimulation. The performances of global and sectoral multifocal steady state visual-evoked potentials metrics to discriminate glaucomatous from healthy eyes were compared with global and sectoral SAP parameters. The repeatability of the BCI device measurements was assessed by collecting results of repeated testing in 20 eyes of 10 participants with glaucoma for 3 sessions of measurements separated by weekly intervals. Receiver operating characteristic curves summarizing diagnostic accuracy. Intraclass correlation coefficients and coefficients of variation for assessing repeatability. Among the 33 participants with glaucoma, 19 (58%) were white, 12 (36%) were black, and 2 (6%) were Asian, while among the 17 participants with healthy eyes, 9 (53%) were white, 8 (47%) were black, and none were Asian. The receiver operating characteristic curve area for the global BCI multifocal steady state visual-evoked potentials parameter was 0.92 (95% CI, 0.86-0.96), which was larger than for SAP mean deviation (area under the curve, 0.81; 95% CI, 0.72-0.90), SAP mean sensitivity (area under the curve, 0.80; 95% CI, 0

  8. Adjusted functional boxplots for spatio-temporal data visualization and outlier detection

    KAUST Repository

    Sun, Ying

    2011-10-24

    This article proposes a simulation-based method to adjust functional boxplots for correlations when visualizing functional and spatio-temporal data, as well as detecting outliers. We start by investigating the relationship between the spatio-temporal dependence and the 1.5 times the 50% central region empirical outlier detection rule. Then, we propose to simulate observations without outliers on the basis of a robust estimator of the covariance function of the data. We select the constant factor in the functional boxplot to control the probability of correctly detecting no outliers. Finally, we apply the selected factor to the functional boxplot of the original data. As applications, the factor selection procedure and the adjusted functional boxplots are demonstrated on sea surface temperatures, spatio-temporal precipitation and general circulation model (GCM) data. The outlier detection performance is also compared before and after the factor adjustment. © 2011 John Wiley & Sons, Ltd.

  9. Functional organization and visual representations in human ventral lateral prefrontal cortex

    Directory of Open Access Journals (Sweden)

    Annie Wai Yiu Chan

    2013-07-01

    Full Text Available Recent neuroimaging studies in both human and non-human primates have identified face selective activation in the ventral lateral prefrontal cortex even in the absence of working memory demands. Further, research has suggested that this face-selective response is largely driven by the presence of the eyes. However, the nature and origin of visual category responses in the ventral lateral prefrontal cortex remain unclear. Further, in a broader sense, how do these findings relate to our current understandings of lateral prefrontal cortex? What do these findings tell us about the underlying function and organization principles of the ventral lateral prefrontal cortex? What is the future direction for investigating visual representations in this cortex? This review focuses on the function, topography, and circuitry of the ventral lateral prefrontal cortex to enhance our understanding of the evolution and development of this cortex.

  10. Automatic Generation of Web Applications from Visual High-Level Functional Web Components

    Directory of Open Access Journals (Sweden)

    Quan Liang Chen

    2009-01-01

    Full Text Available This paper presents high-level functional Web components such as frames, framesets, and pivot tables, which conventional development environments for Web applications have not yet supported. Frameset Web components provide several editing facilities such as adding, deleting, changing, and nesting of framesets to make it easier to develop Web applications that use frame facilities. Pivot table Web components sum up various kinds of data in two dimensions. They reduce the amount of code to be written by developers greatly. The paper also describes the system that implements these high-level functional components as visual Web components. This system assists designers in the development of Web applications based on the page-transition framework that models a Web application as a set of Web page transitions, and by using visual Web components, makes it easier to write processes to be executed when a Web page transfers to another.

  11. Sparse Approximation of Images Inspired from the Functional Architecture of the Primary Visual Areas

    Directory of Open Access Journals (Sweden)

    Laurent Perrinet

    2007-01-01

    Full Text Available Several drawbacks of critically sampled wavelets can be solved by overcomplete multiresolution transforms and sparse approximation algorithms. Facing the difficulty to optimize such nonorthogonal and nonlinear transforms, we implement a sparse approximation scheme inspired from the functional architecture of the primary visual cortex. The scheme models simple and complex cell receptive fields through log-Gabor wavelets. The model also incorporates inhibition and facilitation interactions between neighboring cells. Functionally these interactions allow to extract edges and ridges, providing an edge-based approximation of the visual information. The edge coefficients are shown sufficient for closely reconstructing the images, while contour representations by means of chains of edges reduce the information redundancy for approaching image compression. Additionally, the ability to segregate the edges from the noise is employed for image restoration.

  12. Visual daily functioning of chronic stroke patients assessed by goal attainment scaling after visual restorative training: an explorative study

    NARCIS (Netherlands)

    Bergsma, D.P.; Baars-Elsinga, A.; Sibbel, J.; Lubbers, P.; Visser-Meily, A.J.M.A.

    2014-01-01

    OBJECTIVE: To determine visual training effects on measures of daily life activities in cerebral blindness patients. METHOD: The study design was an explorative pre-post test design of patients in the chronic phase of stroke (not greater-than8 months) with visual field defects. Twelve hemianopic pat

  13. Visual functioning and quality of life in the subfoveal radiotherapy study (SFRADS): SFRADS report 2

    OpenAIRE

    Stevenson, Michael; Hart, P M; Chakravarthy, Usha; Mackenzie, G; Bird, A C; Owens, S.L.; Chisholm, J.H.; Hall, V; Houston, R F; McCulloch, D W; Plowman, N.

    2005-01-01

    Aims: To determine whether or not self reported visual functioning and quality of life in patients with choroidal neovascularisation caused by age related macular degeneration (AMD) is better in those treated with 12 Gy external beam radiotherapy in comparison with untreated subjects. Methods: A multicentre single masked randomised controlled trial of 12 Gy of external beam radiation therapy (EBRT) delivered as 6x2 Gy fractions to the macula of an affected eye versus observation. Patients wit...

  14. Development of a short version of the visual function questionnaire using item-response theory.

    Directory of Open Access Journals (Sweden)

    Shunichi Fukuhara

    Full Text Available PURPOSE: In clinical ophthalmology as in other fields, measuring patient-reported outcomes imposes a burden on patients. To decrease that burden, we used item-response theory (IRT to develop and test a short version of the National Eye Institute's Visual Function Questionnaire (VFQ. METHODS: We analyzed VFQ data from 276 adults in Japan. Most of them had glaucoma, cataract, or macular degeneration. Their visual acuity (Snellen fraction averaged 20/120 (range: 20/13 to 20/2000 for the better eye, and 20/200 (range: 20/13 to 20/2000 for the worse eye. We used a polytomous IRT model, the Generalized Partial Credit Model as implemented in software for parameter scaling of rating data (PARSCALE. To select items for inclusion in the short version we examined each item's location on the latent-trait continuum, its slope, and its frequency of missing data. We also ensured representation of all 7 domains that are important in Japan. To examine the characteristics of the resulting scale, we computed its test information (an index of precision that can vary with the value of the latent trait, and carried out validation testing. RESULTS: From 32 of the original VFQ items, we selected 11. The scale comprising those 11 items (the VFQ-J11 had test information greater than 9 for values of the latent trait between -2.0 and +0.8. The item thresholds were well-targeted for patients with vision problems. Scores on the VFQ-J11 correlated strongly and in the expected direction with measures of visual field and corrected visual acuity. As expected for a valid measure, those scores also improved by a large amount (almost one standard deviation after cataract surgery. CONCLUSION: This 11-item instrument can provide reliable and the valid data on visual functioning in patients with ophthalmic problems. It is expected to be less of a burden on respondents, while it maintains good psychometric properties.

  15. Utility values for glaucoma in Brazil and their correlation with visual function

    Directory of Open Access Journals (Sweden)

    Paletta Guedes RA

    2014-03-01

    Full Text Available Ricardo Augusto Paletta Guedes,1–3 Vanessa Maria Paletta Guedes,1–3 Sirley Maria Freitas,2 Alfredo Chaoubah1 1Federal University of Juiz de Fora, 2Paletta Guedes Ophthalmological Center, 3Santa Casa de Misericórdia Hospital, Juiz de Fora, Brazil Purpose: We sought to identify the utility values in a group of Brazilian patients with primary open-angle glaucoma (POAG, and to assess its impact on visual acuity (VA and mean deviation index values. Materials and methods: This was a cross-sectional study of consecutive patients with POAG, who were interviewed using three methods for obtaining utility values: time trade-off (TTO, standard gamble anchored at risk of death (SG1, and standard gamble anchored at risk of blindness (SG2. Visual function variables (VA and mean deviation index in the better eye and sociodemographic characteristics (age, sex, race, and educational level were also obtained for statistical analysis. Results: The mean age (± standard deviation of the study population (n=227 was 65.7 (±15.1 years. Mean utility values for the entire population were 0.82 from TTO, 0.90 from SG1, and 0.93 from SG2 (P<0.0001. Age, race, and sex had no influence on the utility values. Higher education tended to predict higher values by TTO, but not by SG1 or SG2. Visual function variables had an influence on utility values. The more advanced the visual loss, whether measured by VA or perimetry, in the better eye, the lower the utility values by all three methods. Conclusion: We obtained utility values for Brazilian patients with POAG, as well as specific values for different levels of vision loss. Keywords: primary open-angle glaucoma, visual acuity, quality of life, utility, disease severity

  16. Measures of visual pathway structure and function in MS: Clinical usefulness and role for MS trials.

    Science.gov (United States)

    Galetta, Kristin M; Balcer, Laura J

    2013-07-01

    Over the past decade, the visual pathway in multiple sclerosis (MS) has become an important system for assessing both patient function and disease burden. Abnormalities of low-contrast acuity, long recognized as important correlates of driving, facial recognition, and other activities of daily living, are now noted to be common among patients with MS, even among those with no history of acute optic neuritis (ON). Low-contrast letter acuity scores correlate well with brain MRI lesion burden, visual-evoked potential (VEP) amplitudes, health-related quality of life (QOL), and retinal nerve fiber layer (RNFL) axonal and neuronal loss as measured by optical coherence tomography (OCT). Axonal and neuronal degeneration in MS is likely to be an important cause of visual impairment and disability, particularly among patients with progressive MS subtypes. With the advent of OCT and the use of low-contrast letter acuity charts in MS research and clinical trials, the structure-function correlations afforded by the anterior visual pathway can be assessed and potentially harnessed as a model for testing new therapies. Recent advances in OCT, such as high resolution spectral-domain techniques and computerized algorithms for image analysis, have allowed for measurement of specific retinal layers, including the ganglion cell (GCL) neuronal layer and its intimately associated, thin layer of interneurons, the inner plexiform layer (IPL). Longitudinal collaborative studies of GCL+IPL thinning and RNFL axonal loss are providing an in vivo view into neuroretinal pathology, and are providing new insights into how the visual pathway may reflect overall mechanisms of disease in MS. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Functional and structural comparison of visual lateralization in birds – similar but still different

    Directory of Open Access Journals (Sweden)

    Martina eManns

    2014-03-01

    Full Text Available Vertebrate brains display physiological and anatomical left-right differences, which are related to hemispheric dominances for specific functions. Functional lateralizations likely rely on structural left-right differences in intra- and interhemispheric connectivity patterns that develop in tight gene-environment interactions. The visual systems of chickens and pigeons show that asymmetrical light stimulation during ontogeny induces a dominance of the left hemisphere for visuomotor control that is paralleled by projection asymmetries within the ascending visual pathways. But structural asymmetries vary essentially between both species concerning the affected pathway (thalamo- vs. tectofugal system, constancy of effects (transient vs. permanent, and the hemisphere receiving stronger bilateral input (right vs. left. These discrepancies suggest that at least two aspects of visual processes are influenced by asymmetric light stimulation: 1. Visuomotor dominance develops within the ontogenetically stronger stimulated hemisphere but not necessarily in the one receiving stronger bottom-up input. As a secondary consequence of asymmetrical light experience, lateralized top-down mechanisms play a critical role in the emergence of hemispheric dominance. 2. Ontogenetic light experiences may affect the dominant use of left- and right-hemispheric strategies. Evidences from social and spatial cognition tasks indicate that chickens rely more on a right-hemispheric global strategy whereas pigeons display a dominance of the left hemisphere. Thus, behavioural asymmetries are linked to a stronger bilateral input to the right hemisphere in chickens but to the left one in pigeons. The degree of bilateral visual input may determine the dominant visual processing strategy when redundant encoding is possible. This analysis supports that environmental stimulation affects the balance between hemispheric-specific processing by lateralized interactions of bottom-up and top

  18. Psychophysical "blinding" methods reveal a functional hierarchy of unconscious visual processing.

    Science.gov (United States)

    Breitmeyer, Bruno G

    2015-09-01

    Numerous non-invasive experimental "blinding" methods exist for suppressing the phenomenal awareness of visual stimuli. Not all of these suppressive methods occur at, and thus index, the same level of unconscious visual processing. This suggests that a functional hierarchy of unconscious visual processing can in principle be established. The empirical results of extant studies that have used a number of different methods and additional reasonable theoretical considerations suggest the following tentative hierarchy. At the highest levels in this hierarchy is unconscious processing indexed by object-substitution masking. The functional levels indexed by crowding, the attentional blink (and other attentional blinding methods), backward pattern masking, metacontrast masking, continuous flash suppression, sandwich masking, and single-flash interocular suppression, fall at progressively lower levels, while unconscious processing at the lowest levels is indexed by eye-based binocular-rivalry suppression. Although unconscious processing levels indexed by additional blinding methods is yet to be determined, a tentative placement at lower levels in the hierarchy is also given for unconscious processing indexed by Troxler fading and adaptation-induced blindness, and at higher levels in the hierarchy indexed by attentional blinding effects in addition to the level indexed by the attentional blink. The full mapping of levels in the functional hierarchy onto cortical activation sites and levels is yet to be determined. The existence of such a hierarchy bears importantly on the search for, and the distinctions between, neural correlates of conscious and unconscious vision. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Attentional costs of visually guided walking: effects of age, executive function and stepping-task demands.

    Science.gov (United States)

    Mazaheri, Masood; Roerdink, Melvyn; Bood, Robert Jan; Duysens, Jacques; Beek, Peter J; Peper, C Lieke E

    2014-01-01

    During walking, attention needs to be flexibly allocated to deal with varying environmental constraints. This ability may be affected by aging and lower overall executive function. The present study examined the influence of aging and executive function on the attentional costs of visually guided walking under different task demands. Three groups, young adults (n=15) and elderly adults with higher (n=16) and lower (n=10) executive function, walked on a treadmill in three conditions: uncued walking and walking with regular and irregular patterns of visual stepping targets projected onto the belt. Attentional costs were assessed using a secondary probe reaction time task and corrected by subtracting baseline single-task reaction time, yielding an estimate of the additional attentional costs of each walking condition. We found that uncued walking was more attentionally demanding for elderly than for young participants. In young participants, the attentional costs increased significantly from uncued to regularly cued to irregularly cued walking, whereas for the higher executive function group, attentional costs only increased significantly from regularly cued to irregularly cued walking. For the group with lower executive function, no significant differences were observed. The observed decreased flexibility of elderly, especially those with lower executive function, to allocate additional attentional resources to more challenging walking conditions may be attributed to the already increased attentional costs of uncued walking, presumably required for visuomotor and/or balance control of walking.

  20. Diagnostic classification of intrinsic functional connectivity highlights somatosensory, default mode, and visual regions in autism.

    Science.gov (United States)

    Chen, Colleen P; Keown, Christopher L; Jahedi, Afrooz; Nair, Aarti; Pflieger, Mark E; Bailey, Barbara A; Müller, Ralph-Axel

    2015-01-01

    Despite consensus on the neurological nature of autism spectrum disorders (ASD), brain biomarkers remain unknown and diagnosis continues to be based on behavioral criteria. Growing evidence suggests that brain abnormalities in ASD occur at the level of interconnected networks; however, previous attempts using functional connectivity data for diagnostic classification have reached only moderate accuracy. We selected 252 low-motion resting-state functional MRI (rs-fMRI) scans from the Autism Brain Imaging Data Exchange (ABIDE) including typically developing (TD) and ASD participants (n = 126 each), matched for age, non-verbal IQ, and head motion. A matrix of functional connectivities between 220 functionally defined regions of interest was used for diagnostic classification, implementing several machine learning tools. While support vector machines in combination with particle swarm optimization and recursive feature elimination performed modestly (with accuracies for validation datasets ensemble learning method. Among the 100 most informative features (connectivities), for which this peak accuracy was achieved, participation of somatosensory, default mode, visual, and subcortical regions stood out. Whereas some of these findings were expected, given previous findings of default mode abnormalities and atypical visual functioning in ASD, the prominent role of somatosensory regions was remarkable. The finding of peak accuracy for 100 interregional functional connectivities further suggests that brain biomarkers of ASD may be regionally complex and distributed, rather than localized.

  1. Diagnostic classification of intrinsic functional connectivity highlights somatosensory, default mode, and visual regions in autism

    Directory of Open Access Journals (Sweden)

    Colleen P. Chen

    2015-01-01

    Full Text Available Despite consensus on the neurological nature of autism spectrum disorders (ASD, brain biomarkers remain unknown and diagnosis continues to be based on behavioral criteria. Growing evidence suggests that brain abnormalities in ASD occur at the level of interconnected networks; however, previous attempts using functional connectivity data for diagnostic classification have reached only moderate accuracy. We selected 252 low-motion resting-state functional MRI (rs-fMRI scans from the Autism Brain Imaging Data Exchange (ABIDE including typically developing (TD and ASD participants (n = 126 each, matched for age, non-verbal IQ, and head motion. A matrix of functional connectivities between 220 functionally defined regions of interest was used for diagnostic classification, implementing several machine learning tools. While support vector machines in combination with particle swarm optimization and recursive feature elimination performed modestly (with accuracies for validation datasets <70%, diagnostic classification reached a high accuracy of 91% with random forest (RF, a nonparametric ensemble learning method. Among the 100 most informative features (connectivities, for which this peak accuracy was achieved, participation of somatosensory, default mode, visual, and subcortical regions stood out. Whereas some of these findings were expected, given previous findings of default mode abnormalities and atypical visual functioning in ASD, the prominent role of somatosensory regions was remarkable. The finding of peak accuracy for 100 interregional functional connectivities further suggests that brain biomarkers of ASD may be regionally complex and distributed, rather than localized.

  2. Effects of the AMPA antagonist ZK 200775 on visual function: a randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Richard Bergholz

    Full Text Available BACKGROUND: ZK 200775 is an antagonist at the alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA receptor and had earned attention as a possible neuroprotective agent in cerebral ischemia. Probands receiving the agent within phase I trials reported on an alteration of visual perception. In this trial, the effects of ZK 200775 on the visual system were analyzed in detail. METHODOLOGY: In a randomised controlled trial we examined eyes and vision before and after the intravenous administration of two different doses of ZK 200775 and placebo. There were 3 groups of 6 probands each: Group 1 recieved 0.03 mg/kg/h, group 2 0.75 mg/kg/h of ZK 200775, the control group received 0.9% sodium chloride solution. Probands were healthy males aged between 57 and 69 years. The following methods were applied: clinical examination, visual acuity, ophthalmoscopy, colour vision, rod absolute threshold, central visual field, pattern-reversal visual evoked potentials (pVEP, ON-OFF and full-field electroretinogram (ERG. PRINCIPAL FINDINGS: No effect of ZK 200775 was seen on eye position or motility, stereopsis, pupillary function or central visual field testing. Visual acuity and dark vision deteriorated significantly in both treated groups. Color vision was most remarkably impaired. The dark-adapted ERG revealed a reduction of oscillatory potentials (OP and partly of the a- and b-wave, furthermore an alteration of b-wave morphology and an insignificantly elevated b/a-ratio. Cone-ERG modalities showed decreased amplitudes and delayed implicit times. In the ON-OFF ERG the ON-answer amplitudes increased whereas the peak times of the OFF-answer were reduced. The pattern VEP exhibited lower amplitudes and prolonged peak times. CONCLUSIONS: The AMPA receptor blockade led to a strong impairment of typical OFF-pathway functions like color vision and the cone ERG. On the other hand the ON-pathway as measured by dark vision and the scotopic ERG was affected as well

  3. [Detection of latent disorders of visual function during ambulatory care of children].

    Science.gov (United States)

    Puchkovskaia, N A; Serdiuchenko, V I; Seniakina, A S; Balezina, T V; Boĭchuk, I M

    1989-01-01

    For the purpose to select tests for diagnosis of latent disturbances of visual functions, dynamic observation was conducted over 88 healthy school children within 5 years (from the 3d to the 8th form). Once a year, the children underwent examination of visual acuity for far and near, the state of binocular vision on a synoptophore and a color test, the volume of relative and absolute accommodation, muscular balance of eyes for far and near, contrast sensibility, the time of perception of the negative successive contrast, refraction. For the period of 5 years, 7 children developed myopia of low degree, 32 showed transitory or lasting reduction of visual acuity due to spasm of accommodation. The authors believe that the most rapid and informative tests for diagnosis of latent disturbances in accommodation-convergence system are visual acuity for near, the volume of absolute accommodation, the threshold of remote vision, muscular balance of eyes for near. It is recommended to use these tests widely when conducting ophthalmologic thorough prophylactic examinations of children.

  4. Trends in Visual Health Inequalities in Childhood Through Associations of Visual Function With Sex and Social Position Across 3 UK Birth Cohorts.

    Science.gov (United States)

    Bountziouka, Vasiliki; Cumberland, Phillippa M; Rahi, Jugnoo S

    2017-08-10

    Despite the existing country-specific strategies tackling social inequalities in visual health in adults, little is known about trends in visual function in childhood and its association with social position. To investigate the distribution of childhood visual function in the United Kingdom and associations with early-life social position between 1961 and 1986, a period of significant social change. Longitudinal cohort study using harmonized data sets from the British 1946, 1958, and 1970 national birth cohorts. In total, 14 283 cohort members with complete data on visual acuity at age 15 or 16 years, measured in 1961, 1974, and 1986, respectively, for each cohort, and social position were assessed. Using habitual distance visual acuity (with correction if prescribed), participants were assigned to a visual function category ranging from bilateral normal to visual impairment/severe visual impairment/blindness (International Statistical Classification of Diseases, Tenth Revision, Clinical Modification). Distribution of visual function over time and associations with social position (risk ratios [RRs] and 95% confidence intervals) were analyzed. Complete data were available for 3152 participants (aged 15 years; 53% boys [n = 1660]) in the 1946 Medical Research Council National Survey of Health and Development, 6683 participants (aged 16 years; 51% boys [n = 3420]) in the 1958 National Child Development Study, and 4448 participants (aged 16 years; 48% boys [n = 2156]) in the 1970 British Birth Cohort Study. The proportion of children with bilateral normal vision decreased by 1.3% (95% CI, -5.1% to 2.7%) in 1974 and 1.7% (95% CI, -5.9% to 2.7%) in 1986. The risk of overall impaired vision increased by 1.20 times (95% CI, 1.01-1.43) and the risk of visual impairment/severe visual impairment/blindness by 1.75 times (95% CI, 1.03-2.98) during this period. Girls were consistently at increased risk of all vision impairment categories. Higher social position at

  5. Assessment cognitive functions in children with visual impairment by playing method

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    Statiev S. I.

    2010-05-01

    Full Text Available The cognitive functions of children are considered with paropsiss by a playing method. In research 10 children with a paropsis (experimental group and 10 children (control group took part without a paropsis. Age of children - 5-6 years. Directions are rotined adaptation of children to the environment. It is well-proven that a playing method gives the clear estimation of development of cognitive functions for children with paropsiss. In future a method allows to conduct rehabilitation measures on the improvement of the state of visual analyzer of children.

  6. Repeatability of Detecting Visual Cortex Activity in Functional Magnetic Resonance Imaging

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    Mahboubeh Ma'soumbeigi

    2012-03-01

    Full Text Available Introduction As functional magnetic resonance imaging (fMRI is too expensive and time consuming, its frequent implementation is difficult. The aim of this study is to evaluate repeatability of detecting visual cortex activity in fMRI. Materials and Methods In this study, 15 normal volunteers (10 female, 5 male; Mean age±SD: 24.7±3.8 years attended. Functional magnetic resonance images were obtained during a visual task of sine-wave with spatial frequency of 1.84 cpd and temporal frequency of 8 Hz in three scan runs. Two runs of functional images were provided consecutively in a session, and the third run was provided 1-6 weeks later. The activation map was created using the data obtained from the block-designed fMRI study. Voxels whose Z value was above a threshold of 2.3, at a significance level p=0.05, were considered activated. After image processing, the blood oxygen level dependent (BOLD signal changes and the number of activated voxels in response to visual stimuli were compared in different runs. Results The results of this study demonstrate no significant difference between the number of activated voxels and BOLD signal in first and second runs in one session (Paired t-test, p>0.05. Moreover, there is a considerable correlation between first and second scan runs (rsignal=0.74, p=0.006 and rvoxel=0.62, p=0.03, while the correlation between the runs in separate sessions is weak (rsignal=0.28, p=0.38 and rvoxel=0.32, p=0.31. Conclusion Since the repeatability of BOLD signal and number of activated voxels in one session is considerably better than that in the separate sessions, it is suggested that in fMRI visual studies that need repeated scanning, scans should be acquired during a single session.

  7. Defining the real-world reproducibility of visual grading of left ventricular function and visual estimation of left ventricular ejection fraction: impact of image quality, experience and accreditation.

    Science.gov (United States)

    Cole, Graham D; Dhutia, Niti M; Shun-Shin, Matthew J; Willson, Keith; Harrison, James; Raphael, Claire E; Zolgharni, Massoud; Mayet, Jamil; Francis, Darrel P

    2015-10-01

    Left ventricular function can be evaluated by qualitative grading and by eyeball estimation of ejection fraction (EF). We sought to define the reproducibility of these techniques, and how they are affected by image quality, experience and accreditation. Twenty apical four-chamber echocardiographic cine loops (Online Resource 1-20) of varying image quality and left ventricular function were anonymized and presented to 35 operators. Operators were asked to provide (1) a one-phrase grading of global systolic function (2) an "eyeball" EF estimate and (3) an image quality rating on a 0-100 visual analogue scale. Each observer viewed every loop twice unknowingly, a total of 1400 viewings. When grading LV function into five categories, an operator's chance of agreement with another operator was 50% and with themself on blinded re-presentation was 68%. Blinded eyeball LVEF re-estimates by the same operator had standard deviation (SD) of difference of 7.6 EF units, with the SD across operators averaging 8.3 EF units. Image quality, defined as the average of all operators' assessments, correlated with EF estimate variability (r = -0.616, p visual grading agreement (r = 0.58, p visual grading of LV function and LVEF estimation is dependent on image quality, but individuals cannot themselves identify when poor image quality is disrupting their LV function estimate. Clinicians should not assume that patients changing in grade or in visually estimated EF have had a genuine clinical change.

  8. Visual function in very low birth weight adolescents : Fifteen-year follow-up of children in southeast Sweden

    OpenAIRE

    Hellgren, Kerstin

    2009-01-01

    Background: Very low birth weight (VLBW < 1500 g) carries an increased risk of visual and cognitive deficits. Long term follow-up studies are sparse. The associations between neural structure and visual and cognitive outcome need to be more fully explored. Aims: To describe visual functions in adolescents with VLBW in comparison with a matched control group and to investigate associations with white matter damage of immaturity (WMDI), optic disc measurements and cognitive ...

  9. A biologically inspired psychometric function for accuracy of visual identification as a function of exposure duration

    DEFF Research Database (Denmark)

    Petersen, Anders; Andersen, Tobias

    The psychometric function of letter identification is typically described as a function of stimulus intensity. However, the effect of stimulus exposure duration on letter identification remains poorly described. This is surprising because the effect of exposure duration has played a central role ...

  10. A biologically inspired psychometric function for accuracy of visual identification as a function of exposure duration

    DEFF Research Database (Denmark)

    Petersen, Anders; Andersen, Tobias

    The psychometric function of letter identification is typically described as a function of stimulus intensity. However, the effect of stimulus exposure duration on letter identification remains poorly described. This is surprising because the effect of exposure duration has played a central role......-Z) was presented at the centre of the screen. Exposure duration was varied from 5 to 210 milliseconds. The letter was followed by a pattern mask. Three subjects each completed 54,080 trials in a 26-Alternative Forced Choice procedure. We compared the exponential, the gamma and the Weibull psychometric functions......, all of these having a temporal offset included, as well as the ex-Gaussian, and finally a new psychometric function, motivated from single-neuron studies by (Albrecht, Geisler, Frazor & Crane, 2002). The new psychometric function stands out by having a nonmonotonous hazard rate which is initially...

  11. Alfred Walter Campbell and the visual functions of the occipital cortex.

    Science.gov (United States)

    Macmillan, Malcolm

    2014-07-01

    In his pioneering cytoarchitectonic studies of the human brain, Alfred Walter Campbell identified two structurally different areas in the occipital lobes and assigned two different kinds of visual functions to them. The first area, the visuosensory, was essentially on the mesial surface of the calcarine fissure. It was the terminus of nervous impulses generated in the retina and was where simple visual sensations arose. The second area, the visuopsychic, which surrounded or invested the first, was where sensations were interpreted and elaborated into visual perceptions. I argue that Campbell's distinction between the two areas was the starting point for the eventual differentiation of areas V1-V5. After a brief outline of Campbell's early life and education in Australia and of his Scottish medical education and early work as a pathologist at the Lancashire County Lunatic Asylum at Rainhill near Liverpool, I summarise his work on the human brain. In describing the structures he identified in the occipital lobes, I analyse the similarities and differences between them and the related structures identified by Joseph Shaw Bolton. I conclude by proposing some reasons for how that work came to be overshadowed by the later studies of Brodmann and for the more general lack of recognition given Campbell and his work. Those reasons include the effect of the controversies precipitated by Campbell's alliance with Charles Sherrington over the functions of the sensory and motor cortices.

  12. Impairment of visual function and retinal ER stress activation in Wfs1-deficient mice.

    Directory of Open Access Journals (Sweden)

    Delphine Bonnet Wersinger

    Full Text Available Wolfram syndrome is an early onset genetic disease (1/180,000 featuring diabetes mellitus and optic neuropathy, associated to mutations in the WFS1 gene. Wfs1-/- mouse model shows pancreatic beta cell atrophy, but its visual performance has not been investigated, prompting us to study its visual function and histopathology of the retina and optic nerve. Electroretinogram and visual evoked potentials (VEPs were performed in Wfs1-/- and Wfs1+/+ mice at 3, 6, 9 and 12 months of age. Fundi were pictured with Micron III apparatus. Retinal ganglion cell (RGC abundance was determined from Brn3a immunolabeling of retinal sections. RGC axonal loss was quantified by electron microscopy in transversal optic nerve sections. Endoplasmic reticulum stress was assessed using immunoglobulin binding protein (BiP, protein disulfide isomerase (PDI and inositol-requiring enzyme 1 alpha (Ire1α markers. Electroretinograms amplitudes were slightly reduced and latencies increased with time in Wfs1-/- mice. Similarly, VEPs showed decreased N+P amplitudes and increased N-wave latency. Analysis of unfolded protein response signaling revealed an activation of endoplasmic reticulum stress in Wfs1-/- mutant mouse retinas. Altogether, progressive VEPs alterations with minimal neuronal cell loss suggest functional alteration of the action potential in the Wfs1-/- optic pathways.

  13. A Clustering-Based Automatic Transfer Function Design for Volume Visualization

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    Tianjin Zhang

    2016-01-01

    Full Text Available The two-dimensional transfer functions (TFs designed based on intensity-gradient magnitude (IGM histogram are effective tools for the visualization and exploration of 3D volume data. However, traditional design methods usually depend on multiple times of trial-and-error. We propose a novel method for the automatic generation of transfer functions by performing the affinity propagation (AP clustering algorithm on the IGM histogram. Compared with previous clustering algorithms that were employed in volume visualization, the AP clustering algorithm has much faster convergence speed and can achieve more accurate clustering results. In order to obtain meaningful clustering results, we introduce two similarity measurements: IGM similarity and spatial similarity. These two similarity measurements can effectively bring the voxels of the same tissue together and differentiate the voxels of different tissues so that the generated TFs can assign different optical properties to different tissues. Before performing the clustering algorithm on the IGM histogram, we propose to remove noisy voxels based on the spatial information of voxels. Our method does not require users to input the number of clusters, and the classification and visualization process is automatic and efficient. Experiments on various datasets demonstrate the effectiveness of the proposed method.

  14. A MATLAB function for 3-D and 4-D topographical visualization in geosciences

    Science.gov (United States)

    Zekollari, Harry

    2016-04-01

    Combining topographical information and spatially varying variables in visualizations is often crucial and inherent to geoscientific problems. Despite this, it is often an impossible or a very time-consuming and difficult task to create such figures by using classic software packages. This is also the case in the widely used numerical computing environment MATLAB. Here a MATLAB function is introduced for plotting a variety of natural environments with a pronounced topography, such as for instance glaciers, volcanoes and lakes in mountainous regions. Landscapes can be visualized in 3-D, with a single colour defining a featured surface type (e.g. ice, snow, water, lava), or with a colour scale defining the magnitude of a variable (e.g. ice thickness, snow depth, water depth, surface velocity, gradient, elevation). As an input only the elevation of the subsurface (typically the bedrock) and the surface are needed, which can be complemented by various input parameters in order to adapt the figure to specific needs. The figures are particularly suited to make time-evolving animations of natural processes, such as for instance a glacier retreat or a lake drainage event. Several visualization examples will be provided alongside with animations. The function, which is freely available for download, only requires the basic package of MATLAB and can be run on any standard stationary or portable personal computer.

  15. Functional lateralization of temporoparietal junction - imitation inhibition, visual perspective-taking and theory of mind.

    Science.gov (United States)

    Santiesteban, Idalmis; Banissy, Michael J; Catmur, Caroline; Bird, Geoffrey

    2015-10-01

    Although neuroimaging studies have consistently identified the temporoparietal junction (TPJ) as a key brain region involved in social cognition, the literature is far from consistent with respect to lateralization of function. For example, during theory-of-mind tasks bilateral TPJ activation is found in some studies but only right hemisphere activation in others. Visual perspective-taking and imitation inhibition, which have been argued to recruit the same socio-cognitive processes as theory of mind, are associated with unilateral activation of either left TPJ (perspective taking) or right TPJ (imitation inhibition). The present study investigated the functional lateralization of TPJ involvement in the above three socio-cognitive abilities using transcranial direct current stimulation. Three groups of healthy adults received anodal stimulation over right TPJ, left TPJ or the occipital cortex prior to performing three tasks (imitation inhibition, visual perspective-taking and theory of mind). In contrast to the extant neuroimaging literature, our results suggest bilateral TPJ involvement in imitation inhibition and visual perspective-taking, while no effect of anodal stimulation was observed on theory of mind. The discrepancy between these findings and those obtained using neuroimaging highlight the efficacy of neurostimulation as a complementary methodological tool in cognitive neuroscience. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  16. Exploration of High-Dimensional Scalar Function for Nuclear Reactor Safety Analysis and Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Dan Maljovec; Bei Wang; Valerio Pascucci; Peer-Timo Bremer; Michael Pernice; Robert Nourgaliev

    2013-05-01

    The next generation of methodologies for nuclear reactor Probabilistic Risk Assessment (PRA) explicitly accounts for the time element in modeling the probabilistic system evolution and uses numerical simulation tools to account for possible dependencies between failure events. The Monte-Carlo (MC) and the Dynamic Event Tree (DET) approaches belong to this new class of dynamic PRA methodologies. A challenge of dynamic PRA algorithms is the large amount of data they produce which may be difficult to visualize and analyze in order to extract useful information. We present a software tool that is designed to address these goals. We model a large-scale nuclear simulation dataset as a high-dimensional scalar function defined over a discrete sample of the domain. First, we provide structural analysis of such a function at multiple scales and provide insight into the relationship between the input parameters and the output. Second, we enable exploratory analysis for users, where we help the users to differentiate features from noise through multi-scale analysis on an interactive platform, based on domain knowledge and data characterization. Our analysis is performed by exploiting the topological and geometric properties of the domain, building statistical models based on its topological segmentations and providing interactive visual interfaces to facilitate such explorations. We provide a user’s guide to our software tool by highlighting its analysis and visualization capabilities, along with a use case involving dataset from a nuclear reactor safety simulation.

  17. Expression and Function of the Endocannabinoid System in the Retina and the Visual Brain.

    Science.gov (United States)

    Bouchard, Jean-François; Casanova, Christian; Cécyre, Bruno; Redmond, William John

    2016-01-01

    Endocannabinoids are important retrograde modulators of synaptic transmission throughout the nervous system. Cannabinoid receptors are seven transmembrane G-protein coupled receptors favoring Gi/o protein. They are known to play an important role in various processes, including metabolic regulation, craving, pain, anxiety, and immune function. In the last decade, there has been a growing interest for endocannabinoids in the retina and their role in visual processing. The purpose of this review is to characterize the expression and physiological functions of the endocannabinoid system in the visual system, from the retina to the primary visual cortex, with a main interest regarding the retina, which is the best-described area in this system so far. It will show that the endocannabinoid system is widely present in the retina, mostly in the through pathway where it can modulate neurotransmitter release and ion channel activity, although some evidence also indicates possible mechanisms via amacrine, horizontal, and Müller cells. The presence of multiple endocannabinoid ligands, synthesizing and catabolizing enzymes, and receptors highlights various pharmacological targets for novel therapeutic application to retinal diseases.

  18. Exploration of High-Dimensional Scalar Function for Nuclear Reactor Safety Analysis and Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Dan Maljovec; Bei Wang; Valerio Pascucci; Peer-Timo Bremer; Michael Pernice; Robert Nourgaliev

    2013-05-01

    The next generation of methodologies for nuclear reactor Probabilistic Risk Assessment (PRA) explicitly accounts for the time element in modeling the probabilistic system evolution and uses numerical simulation tools to account for possible dependencies between failure events. The Monte-Carlo (MC) and the Dynamic Event Tree (DET) approaches belong to this new class of dynamic PRA methodologies. A challenge of dynamic PRA algorithms is the large amount of data they produce which may be difficult to visualize and analyze in order to extract useful information. We present a software tool that is designed to address these goals. We model a large-scale nuclear simulation dataset as a high-dimensional scalar function defined over a discrete sample of the domain. First, we provide structural analysis of such a function at multiple scales and provide insight into the relationship between the input parameters and the output. Second, we enable exploratory analysis for users, where we help the users to differentiate features from noise through multi-scale analysis on an interactive platform, based on domain knowledge and data characterization. Our analysis is performed by exploiting the topological and geometric properties of the domain, building statistical models based on its topological segmentations and providing interactive visual interfaces to facilitate such explorations. We provide a user’s guide to our software tool by highlighting its analysis and visualization capabilities, along with a use case involving dataset from a nuclear reactor safety simulation.

  19. Large-scale functional models of visual cortex for remote sensing

    Energy Technology Data Exchange (ETDEWEB)

    Brumby, Steven P [Los Alamos National Laboratory; Kenyon, Garrett [Los Alamos National Laboratory; Rasmussen, Craig E [Los Alamos National Laboratory; Swaminarayan, Sriram [Los Alamos National Laboratory; Bettencourt, Luis [Los Alamos National Laboratory; Landecker, Will [PORTLAND STATE UNIV.

    2009-01-01

    Neuroscience has revealed many properties of neurons and of the functional organization of visual cortex that are believed to be essential to human vision, but are missing in standard artificial neural networks. Equally important may be the sheer scale of visual cortex requiring {approx}1 petaflop of computation. In a year, the retina delivers {approx}1 petapixel to the brain, leading to massively large opportunities for learning at many levels of the cortical system. We describe work at Los Alamos National Laboratory (LANL) to develop large-scale functional models of visual cortex on LANL's Roadrunner petaflop supercomputer. An initial run of a simple region VI code achieved 1.144 petaflops during trials at the IBM facility in Poughkeepsie, NY (June 2008). Here, we present criteria for assessing when a set of learned local representations is 'complete' along with general criteria for assessing computer vision models based on their projected scaling behavior. Finally, we extend one class of biologically-inspired learning models to problems of remote sensing imagery.

  20. Significant improvement in dynamic visual acuity after cataract surgery: a promising potential parameter for functional vision.

    Directory of Open Access Journals (Sweden)

    Mingxin Ao

    Full Text Available PURPOSE: Dynamic visual acuity (DVA is a relatively independent parameter for evaluating the ability to distinguish details of a moving target. The present study has been designed to discuss the extent to which age-related cataract impacts DVA in elderly individuals and to determine whether it could be restored after bilateral phacoemulsification combined with intraocular lens implantation surgery. METHODS: Twenty-six elderly cataract patients scheduled for binocular cataract surgery and 30 elderly volunteers without cataract were enrolled in the study. DVA at 15, 30, 60 and 90 degree per second (dps was assessed, and velocity-dependent visual acuity decreases between consecutive speed levels were calculated. RESULTS: Compared with the control group, the patient group exhibited significantly worse DVA performance at all speed levels (p<0.001, and the decreases in velocity-dependent visual acuity were more serious in the patient group at the intervals of 0-15 dps (p<0.001, 15-30 dps (p = 0.007 and 30-60 dps (p = 0.008. Postoperatively, DVA performance at every speed level in the patient group clearly improved (p<0.001 and recovered to levels compatible to the control group. The decrease in visual acuity with increasing speed was less pronounced than during the preoperative phase (p0-15 dps = 0.001, p15-30 dps<0.001 and p30-60 dps = 0.001 and became similar to that of the control group. The postoperative visual benefit regarding DVA was more pronounced than the improvement in static visual acuity (p15 dps = 0.001 and p<0.001 at 30 dps, 60 dps and 90 dps. CONCLUSIONS: The impact of age-related cataract on DVA was more severe than its effects on static visual acuity. After cataract surgery, not only static vision of the patients was restored markedly, but also the dynamic vision. DVA could be an important adjunct to the current evaluation system of functional vision, thereby meriting additional attention in clinical assessment.

  1. Hemispheric Asymmetry of Visual Cortical Response by Means of Functional Transcranial Doppler

    Directory of Open Access Journals (Sweden)

    Marina Roje-Bedekovic

    2012-01-01

    Full Text Available We assessed the visual evoked response and investigated side-to-side differences in mean blood flow velocities (MBFVs by means of functional transcranial Doppler (fTCD in 49 right-handed patients with severe internal carotid artery (ICA stenosis and 30 healthy volunteers, simultaneously in both posterior cerebral arteries (PCAs using 2 MHz probes, successively in the dark and during the white light stimulation. Statistically significant correlation (P=0.001 was shown in healthy and in patients (P0.05. The correlation between ipsilateral left PCA was significantly higher than the one with contralateral right PCA (P<0.05. There is a clear trend towards the lateralisation of the visual evoked response in the right PCA.

  2. Functional mapping of the human visual cortex with intravoxel incoherent motion MRI.

    Directory of Open Access Journals (Sweden)

    Christian Federau

    Full Text Available Functional imaging with intravoxel incoherent motion (IVIM magnetic resonance imaging (MRI is demonstrated. Images were acquired at 3 Tesla using a standard Stejskal-Tanner diffusion-weighted echo-planar imaging sequence with multiple b-values. Cerebro-spinal fluid signal, which is highly incoherent, was suppressed with an inversion recovery preparation pulse. IVIM microvascular perfusion parameters were calculated according to a two-compartment (vascular and non-vascular diffusion model. The results obtained in 8 healthy human volunteers during visual stimulation are presented. The IVIM blood flow related parameter fD* increased 170% during stimulation in the visual cortex, and 70% in the underlying white matter.

  3. Functional MRI Examination of Visual Pathways in Patients with Unilateral Optic Neuritis

    Directory of Open Access Journals (Sweden)

    Giulia Mascioli

    2012-01-01

    Full Text Available The relations between brain areas involved in vision were explored in 8 patients with unilateral acute optic neuritis using functional magnetic resonance imaging (fMRI and diffusion tensor imaging (DTI. In all patients monocular stimulation of affected and unaffected eye elicited significantly different activation foci in the primary visual cortex (V1, whereas the foci evoked in the middle temporal visual area (area V5 were similar in size and in delay of blood-oxygen-level-dependent response. DTI analysis documented lower white matter anisotropy values and reduced fibre reconstruction in the affected compared with the unaffected optic nerves. The preserved activation of area V5 observed in all our patients is an interesting finding that suggests the notion of a different sensitivity of the optic pathways to inflammatory changes.

  4. Relation between visual function index and falls-related factors in patients with age-related cataract

    Directory of Open Access Journals (Sweden)

    Mei-Na Huang

    2016-01-01

    Full Text Available AIM:To investigate the relation between vision function index and falls-related factors in patients with age-related cataract.METHODS:Ninety-six patients with age-related cataract were interviewed using a seven-item visual function questionnaire(VF-7, then classified into poor, moderate, or good visual function group. The differences of the three groups on visual acuity, balance and mobility function, cognition, depressive symptoms, self-reported fear of falling were analyzed. RESULTS:The patients in poor visual function group had older age, tendency to depression, was more afraid of falling, compared with groups with higher score in VF-7, and they had worse visual acuity, performed worse on all balance and mobility tests. CONCLUSION:Poor visual function is related to worse visual acuity, weaker balance and mobility performance in patients with age-related cataract. The VF-7, as a simple and convenient self-reported method, can be used as a falling risk monitoring in patients with age-related cataract.

  5. Altered Automatic Face Processing in Individuals with High-Functioning Autism Spectrum Disorders: Evidence from Visual Evoked Potentials

    Science.gov (United States)

    Fujita, Takako; Kamio, Yoko; Yamasaki, Takao; Yasumoto, Sawa; Hirose, Shinichi; Tobimatsu, Shozo

    2013-01-01

    Individuals with autism spectrum disorders (ASDs) have different automatic responses to faces than typically developing (TD) individuals. We recorded visual evoked potentials (VEPs) in 10 individuals with high-functioning ASD (HFASD) and 10 TD individuals. Visual stimuli consisted of upright and inverted faces (fearful and neutral) and objects…

  6. Asymmetrical Brain Activity Induced by Voluntary Spatial Attention Depends on the Visual Hemifield: A Functional Near-Infrared Spectroscopy Study

    Science.gov (United States)

    Harasawa, Masamitsu; Shioiri, Satoshi

    2011-01-01

    The effect of the visual hemifield to which spatial attention was oriented on the activities of the posterior parietal and occipital visual cortices was examined using functional near-infrared spectroscopy in order to investigate the neural substrates of voluntary visuospatial attention. Our brain imaging data support the theory put forth in a…

  7. Visual Functions in Relation with Neonatal Cerebral Ultrasound, Neurology and Cognitive Development in Very-Low-Birthweight Children

    NARCIS (Netherlands)

    Weisglas-Kuperus, N.; Heersema, D. J.; Baerts, W.; Fetter, W. P. F.; Smrkovsky, M.; van Hof-van Duin, J.; Sauer, P. J. J.

    1993-01-01

    In order to determine the relationship between visual functions and neonatal cerebral ultrasound, neurological examinations and cognitive development, a prospective longitudinal study was conducted in 69 high-risk very-low-birthweight children. Visual development was studied at 1 and 2.6 years of co

  8. Functional Specificity of the Visual Word Form Area: General Activation for Words and Symbols but Specific Network Activation for Words

    Science.gov (United States)

    Reinke, Karen; Fernandes, Myra; Schwindt, Graeme; O'Craven, Kathleen; Grady, Cheryl L.

    2008-01-01

    The functional specificity of the brain region known as the Visual Word Form Area (VWFA) was examined using fMRI. We explored whether this area serves a general role in processing symbolic stimuli, rather than being selective for the processing of words. Brain activity was measured during a visual 1-back task to English words, meaningful symbols…

  9. The Effectiveness of a Multidisciplinary Group Rehabilitation Program on the Psychosocial Functioning of Elderly People Who Are Visually Impaired

    Science.gov (United States)

    Alma, Manna A.; Groothoff, Johan W.; Melis-Dankers, Bart J. M.; Suurmeijer, Theo P. B. M.; van der Mei, Sijrike F.

    2013-01-01

    Introduction: The pilot study reported here determined the effectiveness of a multidisciplinary group rehabilitation program, Visually Impaired Elderly Persons Participating (VIPP), on psychosocial functioning. Methods: The single-group pretest-posttest pilot study included 29 persons with visual impairments (aged 55 and older) who were referred…

  10. Asymmetrical Brain Activity Induced by Voluntary Spatial Attention Depends on the Visual Hemifield: A Functional Near-Infrared Spectroscopy Study

    Science.gov (United States)

    Harasawa, Masamitsu; Shioiri, Satoshi

    2011-01-01

    The effect of the visual hemifield to which spatial attention was oriented on the activities of the posterior parietal and occipital visual cortices was examined using functional near-infrared spectroscopy in order to investigate the neural substrates of voluntary visuospatial attention. Our brain imaging data support the theory put forth in a…

  11. Visualizing functional pathways in the human brain using correlation tensors and magnetic resonance imaging.

    Science.gov (United States)

    Ding, Zhaohua; Xu, Ran; Bailey, Stephen K; Wu, Tung-Lin; Morgan, Victoria L; Cutting, Laurie E; Anderson, Adam W; Gore, John C

    2016-01-01

    Functional magnetic resonance imaging usually detects changes in blood oxygenation level dependent (BOLD) signals from T2*-sensitive acquisitions, and is most effective in detecting activity in brain cortex which is irrigated by rich vasculature to meet high metabolic demands. We recently demonstrated that MRI signals from T2*-sensitive acquisitions in a resting state exhibit structure-specific temporal correlations along white matter tracts. In this report we validate our preliminary findings and introduce spatio-temporal functional correlation tensors to characterize the directional preferences of temporal correlations in MRI signals acquired at rest. The results bear a remarkable similarity to data obtained by diffusion tensor imaging but without any diffusion-encoding gradients. Just as in gray matter, temporal correlations in resting state signals may reflect intrinsic synchronizations of neural activity in white matter. Here we demonstrate that functional correlation tensors are able to visualize long range white matter tracts as well as short range sub-cortical fibers imaged at rest, and that evoked functional activities alter these structures and enhance the visualization of relevant neural circuitry. Furthermore, we explore the biophysical mechanisms underlying these phenomena by comparing pulse sequences, which suggest that white matter signal variations are consistent with hemodynamic (BOLD) changes associated with neural activity. These results suggest new ways to evaluate MRI signal changes within white matter. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Cortical and white matter mapping in the visual system-more than meets the eye: on the importance of functional imaging to understand visual system pathologies.

    Science.gov (United States)

    Raz, Noa; Levin, Netta

    2014-01-01

    Information transmission within the visual system is highly organized with the ultimate goal of accomplishing higher-order, complex visuo-spatial and object identity processing. Perception is dependent on the intactness of the entire system and damage at each stage-in the eye itself, the visual pathways, or within cortical processing-might result in perception disturbance. Herein we will review several examples of lesions along the visual system, from the retina, via the optic nerve and chiasm and through the occipital cortex. We will address their clinical manifestation and their cortical substrate. The latter will be studied via functional magnetic resonance imaging (fMRI) and Diffusion Tensor Imaging (DTI), enabling cortical, and white matter mapping of the human brain. In contrast to traditional signal recording, these procedures enable simultaneous evaluation of the entire brain network engaged when subjects undertake a particular task or evaluate the entirety of associated white matter pathways. These examples provided will highlight the importance of using advanced imaging methods to better understand visual pathologies. We will argue that clinical manifestation cannot always be explained solely by structural damage and a functional view is required to understand the clinical symptom. In such cases we recommend using advanced imaging methods to better understand the neurological basis of visual phenomena.

  13. Cortical and white matter mapping in the visual system- more than meets theeye: on the importance of functional imaging to understand visual systempathologies

    Directory of Open Access Journals (Sweden)

    Noa eRaz

    2014-08-01

    Full Text Available Information transmission within the visual system is highly organized with the ultimate goal of accomplishing higher-order, complex visuo-spatial and object identity processing. Perception is dependent on the intactness of the entire system and damage at each stage – in the eye itself, the visual pathways, or within cortical processing - might result in perception disturbance.Herein we will review several examples of lesions along the visual system, from the retina, via the optic nerve and chiasm and through the occipital cortex. We will address their clinical manifestation and their cortical substrate. The latter will be studied via functional magnetic resonance imaging (fMRI and Diffusion Tensor Imaging (DTI, enabling cortical and white matter mapping of the human brain. In contrast to traditional signal recording, these procedures enable simultaneous evaluation of the entire brain network engaged when subjects undertake a particular task or evaluate the entirety of associated white matter pathways.These examples provided will highlight the importance of using advanced imaging methods to better understand visual pathologies. We will argue that clinical manifestation cannot always be explained solely by structural damage and a functional view is required to understand the clinical symptom. In such cases we recommend using advanced imaging methods to better understand the neurological basis of visual phenomena.

  14. Integration of visual and motor functional streams in the human brain.

    Science.gov (United States)

    Sepulcre, Jorge

    2014-05-01

    A long-standing difficulty in brain research has been to disentangle how information flows across circuits composed by multiple local and distant cerebral areas. At the large-scale level, several brain imaging methods have contributed to the understanding of those circuits by capturing the covariance or coupling patterns of blood oxygen level-dependent (BOLD) activity between distributed brain regions. The hypothesis is that underlying information processes are closely associated to synchronized brain activity, and therefore to the functional connectivity structure of the human brain. In this study, we have used a recently developed method called stepwise functional connectivity analysis. Our results show that motor and visual connectivity merge in a multimodal integration network that links together perception, action and cognition in the human functional connectome. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  15. Visual function improvement using photocromic and selective blue-violet light filtering spectacle lenses in patients affected by retinal diseases

    National Research Council Canada - National Science Library

    L Colombo; E Melardi; P Ferri; G Montesano; S Samir Attaalla; F Patelli; S De Cilla; G Savaresi; L Rossetti

    2017-01-01

    Background To evaluate functional visual parameters using photocromic and selective blue-violet light filtering spectacle lenses in patients affected by central or peripheral scotoma due to retinal diseases...

  16. The Association of Intelligence, Visual-Motor Functioning, and Personality Characteristics With Adaptive Behavior in Individuals With Williams Syndrome.

    Science.gov (United States)

    Fu, Trista J; Lincoln, Alan J; Bellugi, Ursula; Searcy, Yvonne M

    2015-07-01

    Williams syndrome (WS) is associated with deficits in adaptive behavior and an uneven adaptive profile. This study investigated the association of intelligence, visual-motor functioning, and personality characteristics with the adaptive behavior in individuals with WS. One hundred individuals with WS and 25 individuals with developmental disabilities of other etiologies were included in this study. This study found that IQ and visual-motor functioning significantly predicted adaptive behavior in individuals of WS. Visual-motor functioning especially predicted the most amount of unique variance in overall adaptive behavior and contributed to the variance above and beyond that of IQ. Present study highlights the need for interventions that address visual-motor and motor functioning in individuals with WS.

  17. Reduction of Interhemispheric Functional Connectivity in Sensorimotor and Visual Information Processing Pathways in Schizophrenia

    Institute of Scientific and Technical Information of China (English)

    Xu Lang; Le Wang; Chuan-Jun Zhuo; Feng Jia; Li-Na Wang; Chun-Li Wang

    2016-01-01

    Background:Previous studies have demonstrated interhemispheric functional connectivity alterations in schizophrenia.However,the relationship between these alterations and the disease state of schizophrenia is largely unknown.Therefore,we aimed to investigate this relationship using voxel-mirrored homotopic connectivity (VMHC) method.Methods:This study enrolled 36 schizophrenia patients with complete remission,58 schizophrenia patients with incomplete remission and 55 healthy controls.The VMHC was calculated based on resting-state functional magnetic resonance imaging data.Differences in VMHC among three groups were compared using one-way analysis of variance.A brain region with a significant difference in VMHC was defined as a region of interest (ROI),and the mean VMHC value in the ROI was extracted for the post hoc analysis,i.e.,pair-wise comparisons across the three groups.Results:VMHC in the visual region (inferior occipital and fusiform gyri) and the sensorimotor region (paracentral lobule) showed significant differences among the three groups (P < 0.05,a false discovery rate method corrected).Pair-wise comparisons in thepost hoc analysis showed that VMHC of the visual and sensorimotor regions in schizophrenia patients with complete remission and incomplete remission was lower than that in healthy controls (P < 0.05,Bonferroni corrected);however,there was no significant difference between the two patient subgroups.Conclusions:Interhemispheric functional connectivity in the sensorimotor and visual processing pathways was reduced in patients with schizophrenia,but this reduction was unrelated to the disease state;thus,this reduction may serve as a trait marker of schizophrenia.

  18. [Efficacy of topical ketorolac for improving visual function after photocoagulation in diabetic patients with focal macular edema].

    Science.gov (United States)

    Razo Blanco-Hernández, Dulce Milagros; Lima-Gómez, Virgilio; Asbun-Bojalil, Juan

    2014-01-01

    Photocoagulation reduces the incidence of visual loss in diabetic patients with focal macular edema, but it can induce it for Efficacy of topical ketorolac for improving visual function after photocoagulation in diabetic patients with focal macular edema 6 weeks after treatment and produces visual improvement in some cases. Topical ketorolac may reduce the inflammation caused by photocoagulation and improve visual outcome. To determine the efficacy of topical ketorolac for improving visual function after photocoagulation in diabetic patients with focal macular edema. An experimental, comparative, prospective, longitudinal study in diabetic patients with focal macular edema was conducted. Eyes were randomized into two groups of topical treatment for 3 weeks after photocoagulation (A: ketorolac, B: placebo). Best corrected visual acuity before and after treatment was compared in each group (paired t test), and the proportion of eyes with visual improvement was compared between groups (χ(2)). The evaluation was repeated after stratifying for initial visual acuity (≥ 0.5, visual acuity changed from 0.50 to 0.58 (p= 0.003), and from 0.55 to 0.55 in group B (n= 59, p= 0.83); mean percent change was 22.3% in group A and 3.5% in group B (p= 0.03). Visual improvement was identified in 25 eyes from group A (54.3%) and 19 from group B (32.2%, p= 0.019, RR 1.65); the difference only persisted when initial visual acuity was ≥ 0.5 (10 [40%], group A, 5 [14.7%], group B, p= 0.02, RR 2.72). Topical ketorolac was more effective than placebo to improve best corrected visual acuity in diabetic patients with focal macular edema.

  19. Functional double dissociation within the entorhinal cortex for visual scene-dependent choice behavior

    Science.gov (United States)

    Yoo, Seung-Woo; Lee, Inah

    2017-01-01

    How visual scene memory is processed differentially by the upstream structures of the hippocampus is largely unknown. We sought to dissociate functionally the lateral and medial subdivisions of the entorhinal cortex (LEC and MEC, respectively) in visual scene-dependent tasks by temporarily inactivating the LEC and MEC in the same rat. When the rat made spatial choices in a T-maze using visual scenes displayed on LCD screens, the inactivation of the MEC but not the LEC produced severe deficits in performance. However, when the task required the animal to push a jar or to dig in the sand in the jar using the same scene stimuli, the LEC but not the MEC became important. Our findings suggest that the entorhinal cortex is critical for scene-dependent mnemonic behavior, and the response modality may interact with a sensory modality to determine the involvement of the LEC and MEC in scene-based memory tasks. DOI: http://dx.doi.org/10.7554/eLife.21543.001 PMID:28169828

  20. Congenital Cataract:Progress in Surgical Treatment and Postoperative Recovery of Visual Function

    Institute of Scientific and Technical Information of China (English)

    Mingyue Wang; Wei Xiao

    2015-01-01

    Congenital cataract is a common cause of childhood low vi-sion or blindness worldwide..Early surgery should be per-formed in sensitive vision development period to avoid vision deprivation in cases of strabismus and nystagmus develop-ment. Postoperative recovery of visual function is of great sig-nificance for these patients and should include proper postop-erative aphakia correction by the application of a contact lens and secondary implantation of an intraocular lens (IOL). Pa-tients should receive amblyopic training after surgery to im-prove their postoperative visual acuity..Although recent ad-vances in surgery techniques and materials have brought better postoperative visual acuity and less complications , a few post-operative complications can still hamper vision condition and vision development,.including posterior capsule opacification and secondary glaucoma. Surgery in early infancy are risk fac-tors for these two complications..Life-long follow-up is essen-tial for these patients..Further study will continue to address the surgery timing issue and methods that prevent postopera-tive complications.

  1. Visual function among commercial vehicle drivers in the central region of Ghana.

    Science.gov (United States)

    Boadi-Kusi, Samuel Bert; Kyei, Samuel; Asare, Frederick Afum; Owusu-Ansah, Andrew; Awuah, Agnes; Darko-Takyi, Charles

    2016-01-01

    To determine the relationship between some visual functions: colour vision defects, abnormal stereopsis, visual acuity and the occurrence of road traffic accident (RTAs) among commercial vehicle drivers in the central region of Ghana, and to assess their knowledge of these anomalies. A descriptive cross-sectional study employing a multi-stage random sampling approach was conducted in the major commercial towns within the central region of Ghana. Participants were taken through a comprehensive eye examination after the administration of a structured questionnaire. 520 male commercial vehicle drivers were enrolled for this study with a mean age of 39.23 years ±10.96 years and mean visual acuity of 0.02±0.08 logMAR. Protans were more likely to be involved in RTAs (χ(2)=6.194, p=0.034). However, there was no statistically significant association between abnormal stereopsis (OR=0.89 95% CI: 0.44-1.80, p=0.56), poor vision due to refractive error (χ(2)=3.090, p=0.388) and the occurrence of RTAs. While 86.9% were aware of abnormal stereopsis, only 45% were aware of colour vision defects. There was a statistically significant association between stereopsis anomaly and colour vision defect (r=0.371, pstereopsis anomalies, refractive errors and the occurrence of RTAs. Drivers were less knowledgeable on colour vision defects as compared to stereopsis anomalies. Copyright © 2015 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  2. Functional Connectivity of Ventral and Dorsal Visual Streams in Posterior Cortical Atrophy.

    Science.gov (United States)

    Migliaccio, Raffaella; Gallea, Cécile; Kas, Aurélie; Perlbarg, Vincent; Samri, Dalila; Trotta, Laura; Michon, Agnès; Lacomblez, Lucette; Dubois, Bruno; Lehericy, Stéphane; Bartolomeo, Paolo

    2016-01-01

    Posterior cortical atrophy (PCA) induces progressive dysfunction of ventral and dorsal visual networks. Little is known, however, about corresponding changes in functional connectivity (FC). To investigate FC changes in the visual networks, their relationship with cortical atrophy, and the association with Alzheimer's disease (AD) pathology. Ten PCA patients and 28 age-matched controls participated in the study. Using resting state fMRI, we measured FC in ventral and dorsal cortical visual networks, defined on the basis of a priori knowledge of long-range white matter connections. To assess the relationships with AD, we determined AD biomarkers in cerebrospinal fluid and FC in the default mode network (DMN), which is vulnerable to AD pathology. Voxel-based morphometry analysis assessed the pattern of grey matter (GM) atrophy. PCA patients showed GM atrophy in bilateral occipital and inferior parietal regions. PCA patients had lower FC levels in a ventral network than controls, but higher FC in inferior components of the dorsal network. In particular, the increased connectivity correlated with greater GM atrophy in occipital regions. All PCA patients had positive cerebrospinal fluid biomarkers for AD; however, FC in global DMN did not differ from controls. FC in PCA reflects brain structure in a non-univocal way. Hyperconnectivity of dorsal networks may indicate aberrant communication in response to posterior brain atrophy or processes of neural resilience during the initial stage of brain dysfunction. The lack of difference from controls in global DMN FC highlights the atypical nature of PCA with respect to typical AD.

  3. Locating Temporal Functional Dynamics of Visual Short-Term Memory Binding using Graph Modular Dirichlet Energy

    Science.gov (United States)

    Smith, Keith; Ricaud, Benjamin; Shahid, Nauman; Rhodes, Stephen; Starr, John M.; Ibáñez, Augustin; Parra, Mario A.; Escudero, Javier; Vandergheynst, Pierre

    2017-02-01

    Visual short-term memory binding tasks are a promising early marker for Alzheimer’s disease (AD). To uncover functional deficits of AD in these tasks it is meaningful to first study unimpaired brain function. Electroencephalogram recordings were obtained from encoding and maintenance periods of tasks performed by healthy young volunteers. We probe the task’s transient physiological underpinnings by contrasting shape only (Shape) and shape-colour binding (Bind) conditions, displayed in the left and right sides of the screen, separately. Particularly, we introduce and implement a novel technique named Modular Dirichlet Energy (MDE) which allows robust and flexible analysis of the functional network with unprecedented temporal precision. We find that connectivity in the Bind condition is less integrated with the global network than in the Shape condition in occipital and frontal modules during the encoding period of the right screen condition. Using MDE we are able to discern driving effects in the occipital module between 100–140 ms, coinciding with the P100 visually evoked potential, followed by a driving effect in the frontal module between 140–180 ms, suggesting that the differences found constitute an information processing difference between these modules. This provides temporally precise information over a heterogeneous population in promising tasks for the detection of AD.

  4. Visual Scanning Patterns and Executive Function in Relation to Facial Emotion Recognition in Aging

    Science.gov (United States)

    Circelli, Karishma S.; Clark, Uraina S.; Cronin-Golomb, Alice

    2012-01-01

    Objective The ability to perceive facial emotion varies with age. Relative to younger adults (YA), older adults (OA) are less accurate at identifying fear, anger, and sadness, and more accurate at identifying disgust. Because different emotions are conveyed by different parts of the face, changes in visual scanning patterns may account for age-related variability. We investigated the relation between scanning patterns and recognition of facial emotions. Additionally, as frontal-lobe changes with age may affect scanning patterns and emotion recognition, we examined correlations between scanning parameters and performance on executive function tests. Methods We recorded eye movements from 16 OA (mean age 68.9) and 16 YA (mean age 19.2) while they categorized facial expressions and non-face control images (landscapes), and administered standard tests of executive function. Results OA were less accurate than YA at identifying fear (precognition of sad expressions and with scanning patterns for fearful, sad, and surprised expressions. Conclusion We report significant age-related differences in visual scanning that are specific to faces. The observed relation between scanning patterns and executive function supports the hypothesis that frontal-lobe changes with age may underlie some changes in emotion recognition. PMID:22616800

  5. Short-term effects of instillation of a rebamipide suspension on visual function.

    Science.gov (United States)

    Kaido, Minako; Ishida, Reiko; Dogru, Murat; Tsubota, Kazuo

    2014-05-01

    To investigate the short-term adverse effects of using rebamipide for the treatment of dry eye by assessing visual function and optical quality. This interventional noncomparative study included 14 right eyes of 14 healthy volunteers. Serial measurements of visual acuity (VA) and higher-order aberrations were obtained prior to instillation of the rebamipide suspension (baseline) and immediately after and at 5, 10, 20, and 30 min after instillation. Functional VA measurement was performed over a 60-s period with the subject blinking naturally. Ocular aberrations were measured for 10 s while the subject was told not to blink, but no topical anesthesia was applied. Each patient also filled out a questionnaire exploring the rebamipide-associated adverse effects. There was no significant difference between functional VA measured at baseline and at each time point after the instillation of rebamipide. In contrast, the root mean square of third-order and total higher-order aberrations increased significantly immediately after drug instillation (P0.05). The transient reduction in optical quality immediately after administration of rebamipide is corrected by the patient's natural blink reflex. The adverse effects observed in this study do not outweigh the benefits of rebamipide treatment.

  6. APFEL Web a web-based application for the graphical visualization of parton distribution functions

    CERN Document Server

    Carrazza, Stefano; Palazzo, Daniele; Rojo, Juan

    2015-01-01

    We present APFEL Web, a web-based application designed to provide a flexible user-friendly tool for the graphical visualization of parton distribution functions (PDFs). In this note we describe the technical design of the APFEL Web application, motivating the choices and the framework used for the development of this project. We document the basic usage of APFEL Web and show how it can be used to provide useful input for a variety of collider phenomenological studies. Finally we provide some examples showing the output generated by the application.

  7. The effect of disruption of prefrontal cortical function with transcranial magnetic stimulation on visual working memory

    Directory of Open Access Journals (Sweden)

    Elizabeth S Lorenc

    2015-12-01

    Full Text Available It is proposed that feedback signals from the prefrontal cortex (PFC to extrastriate cortex are essential for goal-directed processing, maintenance, and selection of information in visual working memory (VWM. In a previous study, we found that disruption of PFC function with transcranial magnetic stimulation (TMS in healthy individuals impaired behavioral performance on a face/scene matching task and decreased category-specific tuning in extrastriate cortex as measured with functional magnetic resonance imaging (fMRI. In this study, we investigated the effect of disruption of left inferior frontal gyrus (IFG function on the fidelity of neural representations of two distinct information codes: (1 the stimulus category and (2 the goal-relevance of viewed stimuli. During fMRI scanning, subjects were presented face and scene images in pseudo-random order and instructed to remember either faces or scenes. Within both anatomical and functional regions of interest, a multi-voxel pattern classifier was used to quantitatively assess the fidelity of activity patterns representing stimulus category: whether a face or a scene was presented on each trial, and goal relevance, whether the presented image was task relevant (i.e. a face is relevant in a Remember Faces block, but irrelevant in a Remember Scenes block. We found a reduction in the fidelity of the stimulus category code in visual cortex after left IFG disruption, providing causal evidence that lateral PFC modulates object category codes in visual cortex during VWM. In addition, we found that IFG disruption caused a reduction in the fidelity of the goal relevance code in a distributed set of brain regions. These results suggest that the IFG is involved in determining the task-relevance of visual input and communicating that information to a network of regions involved in further processing during VWM. Finally, we found that participants who exhibited greater fidelity of the goal relevance code in the

  8. Features functional activity kinesthetic and visual sensory systems in athletes of different specializations

    Directory of Open Access Journals (Sweden)

    Anatoliy Rovnyy

    2015-02-01

    Full Text Available Purpose: to establish specific effects of different sports on functional status and co mood kinesthetic and visual analyzers skilled athletes. Materials and Methods: the study was conducted on athletes qualified five sports: modern pentathlon, volleyball, basketball, handball and fencing. We used methods of difference sensometry and mathematical statistics. Results revealed that the sensitivity of sensor systems depend on the specifics of sports activities and sports equipment. Conclusions: the complex is set internally sensor and between sensory bonds that are formed on the basis of the specific sports activity.

  9. Neuropsychological presentation and adaptive skills in high-functioning adolescents with visual impairment: A preliminary investigation.

    Science.gov (United States)

    Greenaway, R; Pring, L; Schepers, A; Isaacs, D P; Dale, N J

    2017-01-01

    Studies in infants and young children with congenital visual impairment (VI) have indicated early developmental vulnerabilities, conversely research with older children and adults have highlighted areas of cognitive strength. A minimal amount is known, however, about the possible combination of strengths and weaknesses in adolescence, and this present study therefore aims to explore the neuropsychological presentation and adaptive behavior profile in high-functioning adolescents with congenital VI. Participants completed a battery of commonly used neuropsychological measures assessing memory, executive function, and attention. The measures utilized focused on auditory neuropsychological function, because only subtests that could be completed with auditory administration were suitable for this sample. Parents completed standardized measures of adaptive behavior, executive function, and social communication. Compared to aged-based norms for normal sight, adolescents with VI demonstrated strengths in aspects of working memory and verbal memory. Furthermore, performance across the neuropsychological battery was within or above the average range for the majority of the sample. In contrast, parent-report measures indicated areas of weakness in adaptive functioning, social communication, and behavioral executive functioning. Overall, this study provides preliminary evidence that relative to fully sighted peers, high-functioning adolescents with VI present with an uneven profile of cognitive and adaptive skills, which has important implications for assessment and intervention.

  10. A new computer program for topological, visual analysis of 3D particle configurations based on visual representation of radial distribution function peaks as bonds

    CERN Document Server

    Metere, Alfredo; Dzugutov, Mikhail

    2015-01-01

    We present a new program able to perform unique visual analysis on generic particle systems: PASYVAT (PArticle SYstem Visual Analysis Tool). More specifically, it can perform a selection of multiple interparticle distance ranges from a radial distribution function (RDF) plot and display them in 3D as bonds. This software can be used with any data set representing a system of particles in 3D. In this manuscript the reader will find a description of the program and its internal structure, with emphasis on its applicability in the study of certain particle configurations, obtained from classical molecular dynamics simulation in condensed matter physics.

  11. Social-cognitive brain function and connectivity during visual perspective-taking in autism and schizophrenia.

    Science.gov (United States)

    Eack, Shaun M; Wojtalik, Jessica A; Keshavan, Matcheri S; Minshew, Nancy J

    2017-05-01

    Autism spectrum disorder (ASD) and schizophrenia are neurodevelopmental conditions that are characterized by significant social impairment. Emerging genomic and neurobiological evidence has increasingly pointed to shared pathophysiologic mechanisms in the two disorders. Overlap in social impairment may reflect similar underlying neural dysfunction in social-cognitive brain networks, yet few studies have directly compared brain function and communication between those with ASD and schizophrenia. Outpatients with schizophrenia (n=36), ASD (n=33), and healthy volunteers (n=37) completed a visual perspective-taking task during functional neuroimaging at 3T to assess similarities and differences in fronto-temporal brain function and connectivity during social-cognitive processing. Analyses employed general linear models to examine differences in amplitude of BOLD-signal response between disorder groups, and computed functional connectivity coefficients to investigate differences in the connectivity profiles of networks implicated in social cognition. Despite similar behavioral impairments, participants with ASD and schizophrenia evidenced distinct neural abnormalities during perspective-taking. Functional activation results indicated reduced temporo-parietal junction and medial prefrontal activity in ASD compared to schizophrenia (all Puncorsocial-cognitive impairments that may stem from different underlying abnormalities in the functional organization and communication of the social brain. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. GeneViTo: Visualizing gene-product functional and structural features in genomic datasets

    Directory of Open Access Journals (Sweden)

    Promponas Vasilis J

    2003-10-01

    Full Text Available Abstract Background The availability of increasing amounts of sequence data from completely sequenced genomes boosts the development of new computational methods for automated genome annotation and comparative genomics. Therefore, there is a need for tools that facilitate the visualization of raw data and results produced by bioinformatics analysis, providing new means for interactive genome exploration. Visual inspection can be used as a basis to assess the quality of various analysis algorithms and to aid in-depth genomic studies. Results GeneViTo is a JAVA-based computer application that serves as a workbench for genome-wide analysis through visual interaction. The application deals with various experimental information concerning both DNA and protein sequences (derived from public sequence databases or proprietary data sources and meta-data obtained by various prediction algorithms, classification schemes or user-defined features. Interaction with a Graphical User Interface (GUI allows easy extraction of genomic and proteomic data referring to the sequence itself, sequence features, or general structural and functional features. Emphasis is laid on the potential comparison between annotation and prediction data in order to offer a supplement to the provided information, especially in cases of "poor" annotation, or an evaluation of available predictions. Moreover, desired information can be output in high quality JPEG image files for further elaboration and scientific use. A compilation of properly formatted GeneViTo input data for demonstration is available to interested readers for two completely sequenced prokaryotes, Chlamydia trachomatis and Methanococcus jannaschii. Conclusions GeneViTo offers an inspectional view of genomic functional elements, concerning data stemming both from database annotation and analysis tools for an overall analysis of existing genomes. The application is compatible with Linux or Windows ME-2000-XP operating

  13. Anatomy and function of an excitatory network in the visual cortex.

    Science.gov (United States)

    Lee, Wei-Chung Allen; Bonin, Vincent; Reed, Michael; Graham, Brett J; Hood, Greg; Glattfelder, Katie; Reid, R Clay

    2016-04-21

    Circuits in the cerebral cortex consist of thousands of neurons connected by millions of synapses. A precise understanding of these local networks requires relating circuit activity with the underlying network structure. For pyramidal cells in superficial mouse visual cortex (V1), a consensus is emerging that neurons with similar visual response properties excite each other, but the anatomical basis of this recurrent synaptic network is unknown. Here we combined physiological imaging and large-scale electron microscopy to study an excitatory network in V1. We found that layer 2/3 neurons organized into subnetworks defined by anatomical connectivity, with more connections within than between groups. More specifically, we found that pyramidal neurons with similar orientation selectivity preferentially formed synapses with each other, despite the fact that axons and dendrites of all orientation selectivities pass near (<5 μm) each other with roughly equal probability. Therefore, we predict that mechanisms of functionally specific connectivity take place at the length scale of spines. Neurons with similar orientation tuning formed larger synapses, potentially enhancing the net effect of synaptic specificity. With the ability to study thousands of connections in a single circuit, functional connectomics is proving a powerful method to uncover the organizational logic of cortical networks.

  14. The tumor suppressor gene retinoblastoma-1 is required for retinotectal development and visual function in zebrafish.

    Directory of Open Access Journals (Sweden)

    Michael Gyda

    Full Text Available Mutations in the retinoblastoma tumor suppressor gene (rb1 cause both sporadic and familial forms of childhood retinoblastoma. Despite its clinical relevance, the roles of rb1 during normal retinotectal development and function are not well understood. We have identified mutations in the zebrafish space cadet locus that lead to a premature truncation of the rb1 gene, identical to known mutations in sporadic and familial forms of retinoblastoma. In wild-type embryos, axons of early born retinal ganglion cells (RGC pioneer the retinotectal tract to guide later born RGC axons. In rb1 deficient embryos, these early born RGCs show a delay in cell cycle exit, causing a transient deficit of differentiated RGCs. As a result, later born mutant RGC axons initially fail to exit the retina, resulting in optic nerve hypoplasia. A significant fraction of mutant RGC axons eventually exit the retina, but then frequently project to the incorrect optic tectum. Although rb1 mutants eventually establish basic retinotectal connectivity, behavioral analysis reveals that mutants exhibit deficits in distinct, visually guided behaviors. Thus, our analysis of zebrafish rb1 mutants reveals a previously unknown yet critical role for rb1 during retinotectal tract development and visual function.

  15. Contributions of local speech encoding and functional connectivity to audio-visual speech perception

    Science.gov (United States)

    Giordano, Bruno L; Ince, Robin A A; Gross, Joachim; Schyns, Philippe G; Panzeri, Stefano; Kayser, Christoph

    2017-01-01

    Seeing a speaker’s face enhances speech intelligibility in adverse environments. We investigated the underlying network mechanisms by quantifying local speech representations and directed connectivity in MEG data obtained while human participants listened to speech of varying acoustic SNR and visual context. During high acoustic SNR speech encoding by temporally entrained brain activity was strong in temporal and inferior frontal cortex, while during low SNR strong entrainment emerged in premotor and superior frontal cortex. These changes in local encoding were accompanied by changes in directed connectivity along the ventral stream and the auditory-premotor axis. Importantly, the behavioral benefit arising from seeing the speaker’s face was not predicted by changes in local encoding but rather by enhanced functional connectivity between temporal and inferior frontal cortex. Our results demonstrate a role of auditory-frontal interactions in visual speech representations and suggest that functional connectivity along the ventral pathway facilitates speech comprehension in multisensory environments. DOI: http://dx.doi.org/10.7554/eLife.24763.001 PMID:28590903

  16. Lack of functional specialization of neurons in the mouse primary visual cortex that have expressed calretinin

    Directory of Open Access Journals (Sweden)

    Daniela eCamillo

    2014-09-01

    Full Text Available Calretinin is a calcium-binding protein often used as a marker for a subset of inhibitory interneurons in the mammalian neocortex. We studied the labeled cells in offspring from a cross of a Cre-dependent reporter line with the CR-ires-Cre mice, which express Cre-recombinase in the same pattern as calretinin. We found that in the mature visual cortex, only a minority of the cells that have expressed calretinin and Cre-recombinase during their lifetime is GABAergic and only about 20% are immunoreactive for calretinin. The reason behind this is that calretinin is transiently expressed in many cortical pyramidal neurons during development. To determine whether neurons that express or have expressed calretinin share any distinct functional characteristics, we recorded their visual response properties using GCaMP6s calcium imaging. The average orientation selectivity, size tuning, and temporal and spatial frequency tuning of this group of cells, however, match the response profile of the general neuronal population, revealing the lack of functional specialization for the features studied.

  17. Fourier transformed steady-state flash evoked potentials for continuous monitoring of visual pathway function.

    Science.gov (United States)

    Bergholz, R; Lehmann, T N; Fritz, G; Rüther, K

    2008-05-01

    Monitoring of somatosensory, motor and auditory pathway function by evoked potentials is routine in surgery placing these pathways at risk. However, visual pathway function remains yet inaccessible to a reliable monitoring. For this study, a method of continuous recordings was developed and tested. Steady-state visual evoked potentials were elicited by flash stimulation at 16 Hz and analysed using discrete Fourier transform. Amplitude and phase of the fundamental response were dynamically averaged and continuously plotted in a trend graph. The method was applied on awake individuals with normal vision and on patients undergoing neurosurgery. In most individuals it was possible to continuously record significant responses. Surprisingly, characteristic time-courses of amplitude and phase were observed in several subjects. These findings were attributed mainly to flicker-adaptation. During anesthesia, amplitude and signal-to-noise ratio were markedly smaller. Signal recognition was facilitated when potentials were recorded with a subdural electrode placed directly at the occipital pole. The anesthetic agent propofol had a major impact on the recordings.

  18. Chromatic clocks: Color opponency in non-image-forming visual function.

    Science.gov (United States)

    Spitschan, Manuel; Lucas, Robert J; Brown, Timothy M

    2017-07-01

    During dusk and dawn, the ambient illumination undergoes drastic changes in irradiance (or intensity) and spectrum (or color). While the former is a well-studied factor in synchronizing behavior and physiology to the earth's 24-h rotation, color sensitivity in the regulation of circadian rhythms has not been systematically studied. Drawing on the concept of color opponency, a well-known property of image-forming vision in many vertebrates (including humans), we consider how the spectral shifts during twilight are encoded by a color-opponent sensory system for non-image-forming (NIF) visual functions, including phase shifting and melatonin suppression. We review electrophysiological evidence for color sensitivity in the pineal/parietal organs of fish, amphibians and reptiles, color coding in neurons in the circadian pacemaker in mice as well as sporadic evidence for color sensitivity in NIF visual functions in birds and mammals. Together, these studies suggest that color opponency may be an important modulator of light-driven physiological and behavioral responses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. The origins of metamodality in visual object area LO: Bodily topographical biases and increased functional connectivity to S1.

    Science.gov (United States)

    Tal, Zohar; Geva, Ran; Amedi, Amir

    2016-02-15

    Recent evidence from blind participants suggests that visual areas are task-oriented and sensory modality input independent rather than sensory-specific to vision. Specifically, visual areas are thought to retain their functional selectivity when using non-visual inputs (touch or sound) even without having any visual experience. However, this theory is still controversial since it is not clear whether this also characterizes the sighted brain, and whether the reported results in the sighted reflect basic fundamental a-modal processes or are an epiphenomenon to a large extent. In the current study, we addressed these questions using a series of fMRI experiments aimed to explore visual cortex responses to passive touch on various body parts and the coupling between the parietal and visual cortices as manifested by functional connectivity. We show that passive touch robustly activated the object selective parts of the lateral-occipital (LO) cortex while deactivating almost all other occipital-retinotopic-areas. Furthermore, passive touch responses in the visual cortex were specific to hand and upper trunk stimulations. Psychophysiological interaction (PPI) analysis suggests that LO is functionally connected to the hand area in the primary somatosensory homunculus (S1), during hand and shoulder stimulations but not to any of the other body parts. We suggest that LO is a fundamental hub that serves as a node between visual-object selective areas and S1 hand representation, probably due to the critical evolutionary role of touch in object recognition and manipulation. These results might also point to a more general principle suggesting that recruitment or deactivation of the visual cortex by other sensory input depends on the ecological relevance of the information conveyed by this input to the task/computations carried out by each area or network. This is likely to rely on the unique and differential pattern of connectivity for each visual area with the rest of the

  20. Visualization of the eloquent motor system by integration of MEG, functional, and anisotropic diffusion-weighted MRI in functional neuronavigation.

    Science.gov (United States)

    Kamada, Kyousuke; Houkin, Kiyohiro; Takeuchi, Fumiya; Ishii, Nobuaki; Ikeda, Jun; Sawamura, Yutaka; Kuriki, Shinya; Kawaguchi, Hideaki; Iwasaki, Yoshinobu

    2003-05-01

    In this study, we visualized the eloquent motor system including the somatosensory-motor cortex and corticospinal tract on a neuronavigation system, integrating magnetoencephalography (MEG), functional magnetic resonance imaging (fMRI), and anisotropic diffusion-weighted MRI (ADWI). Four patients with brain lesions adjacent to the eloquent motor system were studied. Motor-evoked responses (MER) by finger-tapping paradigm were acquired with a 1.5-Tesla MR scanner, and somatosensory-evoked magnetic fields (SEF) by median nerve stimulation were measured with a 204-channel MEG system. In the same fMRI examination, ADWI and anatomic three-dimensional T1-weighted imaging (3-D MRI) were obtained. Activated areas of MER, estimated SEF dipoles, and the corticospinal tract on ADWI were coregistered to 3-D MRI, and the combined MR data were transferred to a neuronavigation system (functional neuronavigation). Intraoperative recording of cortical somatosensory-evoked potentials was performed for confirmation of the central sulcus. Combination of fMRI and MEG enabled firm identification of the central sulcus. Functional neuronavigation facilitated extensive tumor resection, having the advantage of sparing the motor cortex and corticospinal tract in all cases. The proposed functional neuronavigation allows neurosurgeons to perform effective and maximal resection of brain lesions, identifying and sparing eloquent cortical components and their subcortical connections. Potential clinical application of this technique is discussed.

  1. Developmental dissociation of visual dorsal stream parvo and magnocellular representations and the functional impact of negative retinotopic BOLD responses.

    Science.gov (United States)

    Duarte, Isabel Catarina; Cunha, Gil; Castelhano, João; Sales, Francisco; Reis, Aldina; Cunha, João Paulo Silva; Castelo-Branco, Miguel

    2013-10-01

    Localized neurodevelopmental defects provide an opportunity to study structure-function correlations in the human nervous system. This unique multimodal case report of epileptogenic dysplasia in the visual cortex allowed exploring visual function across distinct pathways in retinotopic regions and the dorsal stream, in relation to fMRI retinotopic mapping and spike triggered BOLD responses. Pre-surgical EEG/video monitoring, MRI/DTI, EEG/fMRI, PET and SPECT were performed to characterize structure/function correlations in this patient with a very early lesion onset. In addition, we included psychophysical methods (assessing parvo/konio and magnocellular pathways) and retinotopic mapping. We could identify dorsal stream impairment (with extended contrast sensitivity deficits within the input magno system contrasting with more confined parvocellular deficits) with disrupted active visual field input representations in regions neighboring the lesion. Simultaneous EEG/fMRI identified perilesional and retinotopic bilaterally symmetric BOLD deactivation triggered by interictal spikes, which matched the contralateral spread of magnocellular dysfunction revealed in the psychophysical tests. Topographic changes in retinotopic organization further suggested long term functional effects of abnormal electrical discharges during brain development. We conclude that fMRI based visual field cortical mapping shows evidence for retinotopic dissociation between magno and parvocellular function well beyond striate cortex, identifiable in high level dorsal visual representations around visual area V3A which is consistent with the effects of epileptic spike triggered negative BOLD.

  2. Mixed functional microarchitectures for orientation selectivity in the mouse primary visual cortex

    Science.gov (United States)

    Kondo, Satoru; Yoshida, Takashi; Ohki, Kenichi

    2016-01-01

    A minicolumn is the smallest anatomical module in the cortical architecture, but it is still in debate whether it serves as functional units for cortical processing. In the rodent primary visual cortex (V1), neurons with different preferred orientations are mixed horizontally in a salt and pepper manner, but vertical functional organization was not examined. In this study, we found that neurons with similar orientation preference are weakly but significantly clustered vertically in a short length and horizontally in the scale of a minicolumn. Interestingly, the vertical clustering is found only in a part of minicolumns, and others are composed of neurons with a variety of orientation preferences. Thus, the mouse V1 is a mixture of vertical clusters of neurons with various degrees of orientation similarity, which may be the compromise between the brain size and keeping the vertical clusters of similarly tuned neurons at least in a subset of clusters. PMID:27767032

  3. Virtual brain mapping: Meta-analysis and visualization in functional neuroimaging

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup

    Results from functional neuroimaging such as positron emission tomography and functional magnetic resonance are often reported as sets of 3-dimensional coordinates in Talairach stereotactic space. By utilizing data collected in the BrainMap database and from our own small XML database we can...... automatically model and visualize several studies at once. We model a set of 3-dimensional coordinates by a voxelization step where flexible probability density models such as kernel density estimators produce a voxel-volume representation of a study, allowing us to represent all coordinate data in one single...... lists. Image-based indices can be created by singular value decomposition and by matching individual volumes against eigenimages. Individual experiments, sets of experiments as well as results from meta-analyses can be rendered as glyphs, cut-planes or isosurfaces in 3-dimensional Corner Cube...

  4. Improving visual functions in adult amblyopia with combined perceptual training and transcranial random noise stimulation (tRNS

    Directory of Open Access Journals (Sweden)

    Gianluca eCampana

    2014-12-01

    Full Text Available Amblyopia is a visual disorder due to an abnormal pattern of functional connectivity of the visual cortex and characterized by several visual deficits of spatial vision including impairments of visual acuity (VA and of the contrast sensitivity function (CSF. Despite being a developmental disorder caused by reduced visual stimulation during early life (critical period, several studies have shown that extensive visual perceptual training can improve VA and CSF in people with amblyopia even in adulthood. With the present study we assessed whether a much shorter perceptual training regime, in association with high-frequency transcranial electrical stimulation (hf-tRNS, was able to improve visual functions in a group of adult participants with amblyopia. Results show that, in comparison with previous studies where a large number sessions with a similar training regime were used (Polat, Ma-Naim, Belkin & Sagi, 2004, here just eight sessions of training in contrast detection under lateral masking conditions combined with hf-tRNS, were able to substantially improve VA and CSF in adults with amblyopia.

  5. Evaluation of changes in retinal nerve fiber layer thickness and visual functions in cases of optic neuritis and multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Rohit Saxena

    2013-01-01

    Full Text Available Context: Retinal nerve fiber layer (RNFL thinning has been demonstrated in cases of optic neuritis (ON and multiple sclerosis (MS in Caucasian eyes, but no definite RNFL loss pattern or association with visual functions is known in Indian eyes. Aim : To evaluate RNFL thickness in cases of ON and MS, and to correlate it with visual function changes in Indian patients. Settings and Design: Cross-sectional case-control study at a tertiary level institution . Materials and Methods: Cases consisted of patients of (i typical ON without a recent episode (n = 30:39 ON eyes and 21 fellow eyes, (ii MS without ON (n = 15;30 eyes while the controls were age-matched (n = 15; 30 eyes. RNFL thickness was measured using the Stratus 3 °CT. The visual functions tested included the best-corrected visual acuity (BCVA, contrast sensitivity, stereopsis, visual evoked responses, and visual fields. Statistical analysis used: Intergroup analysis was done using ANOVA and Pearson′s correlation coefficient used for associations. Results: RNFL thickness was reduced significantly in the ON and MS patients compared to the controls (P-0.001. Maximum loss is in the temporal quadrant. Lower visual function scores are associated with reduced average overall RNFL thickness. In ON group, RNFL thinning is associated with severe visual field defects while contrast sensitivity has strongest correlation with RNFL in the MS group. Conclusions:RNFL thickness is reduced in ON and MS cases in a pattern similar to Caucasians and is associated with the magnitude of impairment of other visual parameters. Contrast sensitivity and stereoacuity are useful tests to identify subclinical optic nerve involvement in multiple sclerosis.

  6. Improvement of visual debugging tool. Shortening the elapsed time for getting data and adding new functions to compare/combine a set of visualized data

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Katsuyuki; Takemiya, Hiroshi

    2001-03-01

    The visual debugging tool 'vdebug' has been improved, which was designed for the debugging of programs for scientific computing. Improved were the following two points; (1) shortening the elapsed time required for getting appropriate data to visualize; (2) adding new functions which enable to compare and/or combine a set of visualized data originated from two or more different programs. As for shortening elapsed time for getting data, with the improved version of 'vdebug', we could achieve the following results; over hundred times shortening the elapsed time with dbx, pdbx of SX-4 and over ten times with ndb of SR2201. As for the new functions to compare/combine visualized data, it was confirmed that we could easily checked the consistency between the computational results obtained in each calculational steps on two different computers: SP and ONYX. In this report, we illustrate how the tool 'vdebug' has been improved with an example. (author)

  7. Endocrine and visual function after fractionated stereotactic radiotherapy of perioptic tumors

    Energy Technology Data Exchange (ETDEWEB)

    Kocher, M.; Semrau, R.; Mueller, R.P. [Universitaetsklinikum Koeln (Germany). Klinik und Poliklinik fuer Strahlentherapie; Treuer, H.; Hoevels, M.; Sturm, V. [Koeln Univ. (Germany). Dept. of Stereotaxy and Functional Neurosurgery

    2013-02-15

    Purpose: To find out whether the use of stereotactic techniques for fractionated radiotherapy reduces toxicity to the endocrine and visual system in patients with benign perioptic tumors. Patients and methods: From 1993 to 2009, 29 patients were treated with fractionated stereotactic radiotherapy. The most frequent tumor types were grade I meningioma (n = 11) and pituitary adenoma (n = 10, 7 nonfunctioning, 3 growth hormone-producing). Patients were immobilized with the GTC frame (Radionics, USA) and the planning target volume (PTV; median 24.7, 4.6-58.6 ml) was irradiated with a total dose of 52.2 Gy (range, 45.0-55.8 Gy) in 1.8-Gy fractions using a linear accelerator (6 MeV photons) equipped with a micro-multileaf collimator. Maximum doses to the optic system and pituitary gland were 53.4 Gy (range, 11.5-57.6 Gy) and 53.6 Gy (range, 12.0-57.9 Gy). Results: Median follow-up was 45 months (range, 10-105 months). Local control was achieved in all but 1 patient (actuarial rate 92% at 5 years and 10 years). In 9 of 29 patients (31%), partial remission was observed (actuarial response rate 40% at 5 years and 10 years). In 4 of 26 patients (15%) with at least partial pituitary function, new hormonal deficits developed (actuarial rate 21% at 5 years and 10 years). This rate was significantly higher in patients treated for a larger PTV ( 25 ml: 0% vs. 42% at 5 years and 10 years, p = 0.028). Visual function improved in 4 of 15 patients (27%) who had prior impairment. None of the patients developed treatment-related optic neuropathy, but 2 patients experienced new disease-related visual deficits. Conclusion: Fractionated stereotactic radiotherapy for benign tumors of the perioptic and sellar region results in satisfactory response and local control rates and does not affect the visual system. The assumption that patients can be spared hypophyseal insufficiency only holds for small tumors. (orig.)

  8. Visual input controls the functional activity of goldfish Mauthner neuron through the reciprocal synaptic mechanism.

    Science.gov (United States)

    Moshkov, Dmitry A; Shtanchaev, Rashid S; Mikheeva, Irina B; Bezgina, Elena N; Kokanova, Nadezhda A; Mikhailova, Gulnara Z; Tiras, Nadezhda R; Pavlik, Lyubov' L

    2013-03-01

    Goldfish are known to exhibit motor asymmetry due to functional asymmetry of their Mauthner neurons that induce the turns to the right or left during free swimming. It has been previously found that if the less active neuron is subjected to prolonged aimed visual stimulation via its ventral dendrite, the motor asymmetry of goldfish is inverted, testifying that this neuron becomes functionally dominant, while the size of the ventral dendrite under these conditions is reduced 2-3 times compared to its counterpart in mirror neuron. Earlier it has been also revealed that training optokinetic stimulation induces adaptation, a substantial resistance of both fish motor asymmetry and morphofunctional state of Mauthner neurons against prolonged optokinetic stimulation. The aim of this work was to study the cellular mechanisms of the effect of an unusual visual afferent input on goldfish motor asymmetry and Mauthner neuron function in norm and under adaptation. It was shown that serotonin applied onto Mauthner neurons greatly reduces their activity whereas its antagonist ondansetron increases it. Against the background of visual stimulation, serotonin strengthens functional asymmetry between neurons whereas ondansetron smoothes it. Taken together these data suggest the involvement of serotonergic excitatory synaptic transmission in the regulation of Mauthner neurons by vision. Ultrastructural study of the ventral dendrites after prolonged optokinetic stimulation has revealed depletions of numeral axo-axonal synapses with specific morphology, identified by means of immunogold label as serotonergic ones. These latter in turn are situated mainly on shaft boutons, which according to specific ultrastructural features are assigned to axo-dendritic inhibitory synapses. Thus, the excitatory serotonergic synapses seem to affect Mauthner neuron indirectly through inhibitory synapses. Further, it was morphometrically established that adaptation is accompanied by the significant

  9. Gross motor function in children with spastic cerebral palsy and cerebral visual impairment: A comparison between outcomes of the original and the Cerebral Visual Impairment adapted Gross Motor Function Measure-88 (GMFM-88-CVI)

    NARCIS (Netherlands)

    Salavati, M.; Rameckers, E.A.A.; Waninge, A.; Krijnen, W.P.; Steenbergen, B.; Schans, C.P. van der

    2017-01-01

    Purpose: To investigate whether the adapted version of the Gross Motor Function Measure-88 (GMFM-88) for children with Cerebral Palsy (CP) and Cerebral Visual Impairment (CVI) results in higher scores. This is most likely to be a reflection of their gross motor function, however it may be the result

  10. Gross motor function in children with spastic Cerebral Palsy and Cerebral Visual Impairment : A comparison between outcomes of the original and the Cerebral Visual Impairment adapted Gross Motor Function Measure-88 (GMFM-88-CVI)

    NARCIS (Netherlands)

    Salavati, M.; Rameckers, E. A. A.; Waninge, A.; Krijnen, W. P.; Steenbergen, B.; van der Schans, C. P.

    2017-01-01

    Purpose: To investigate whether the adapted version of the Gross Motor Function Measure 88 (GMFM-88) for children with Cerebral Palsy (CP) and Cerebral Visual Impairment (CVI) results in higher scores. This is most likely to be a reflection of their gross motor function, however it may be the result

  11. Gross motor function in children with spastic cerebral palsy and cerebral visual impairment: A comparison between outcomes of the original and the Cerebral Visual Impairment adapted Gross Motor Function Measure-88 (GMFM-88-CVI)

    NARCIS (Netherlands)

    Salavati, M.; Rameckers, E.A.A.; Waninge, A.; Krijnen, W.P.; Steenbergen, B.; Schans, C.P. van der

    2017-01-01

    Purpose: To investigate whether the adapted version of the Gross Motor Function Measure-88 (GMFM-88) for children with Cerebral Palsy (CP) and Cerebral Visual Impairment (CVI) results in higher scores. This is most likely to be a reflection of their gross motor function, however it may be the result

  12. Cerebral activation associated with visually evoked sexual arousal in the limbic system: functional MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Eun, Sung Jong; Kong, Gwang Woo; Kim, Hyung Joong; Seo, Jeong Jin; Kang, Heoung Keun; Cho, Ki Hyun; Yoon, Ka Hyun [School of Medicine, Chonnam National Univ., Kwangju (Korea, Republic of); Kim, Kyung Yo [Wonkwang Univ., Iksan (Korea, Republic of)

    2004-08-01

    To identify the brain centers associated with visually evoked sexual arousal in the human brain, and to investigate the neural mechanism for sexual arousal using functional MRI (fMRI). A total of 20 sexually potent volunteers consisting of 10 males (mean age: 24) and 10 females (mean age: 23) underwent fMRI on a 1.5T MR scanner (GE Signa Horizon). The fMRI data were obtained from 7 slices (10 mm slice thickness) parallel to the AC-PC (anterior commissure and posterior commissure) line, giving a total of 511 MR images. The sexual stimulation consisted of a 1-minute rest with black screen, followed by a 4-minute stimulation by an erotic video film, and concluded with a 2-minute rest. The brain activation maps and their quantification were analyzed by the statistical parametric mapping (SPM 99) program. The brain activation regions associated with visual sexual arousal in the limbic system are the posterior cingulate gyrus, parahippocampal gyrus, hypothalamus, medial cingulate gyrus, thalamus, amygdala, anterior cingulate gyrus, insula, hippocampus, caudate nucleus, globus pallidus and putamen. Especially, the parahippocampal gyrus, cingulate gyrus, thalamus and hypothalamus were highly activated in comparison with other areas. The overall activities of the limbic lobe, diencephalon, and basal ganglia were 11.8%, 10.5%, and 3.4%, respectively. In the correlation test between brain activity and sexual arousal, the hypothalamus and thalamus showed positive correlation, but the other brain areas showed no correlation. The fMRI is useful to quantitatively evaluate the cerebral activation associated with visually evoked, sexual arousal in the human brain. This result may be helpful by providing clinically valuable information on sexual disorder in humans as well as by increasing the understanding of the neuroanatomical correlates of sexual arousal.

  13. FUNCTIONAL HEMISPHERIC SPECIALIZATION FOR TWO LEVELS OF LINGUISTIC INFORMATION PROCESSING: VISUAL IDENTITY

    Directory of Open Access Journals (Sweden)

    ANA MARÍA MARTÍNEZ

    2004-01-01

    Full Text Available Objective: To continue deepening in the lateralitation of tasks of physical identity (PI with alphabetical content andof categorization of verbal stimuli of concrete and abstract content.Method: we Use 48 adults, with understood ages between 18 and 24 years. All the fellows carried out Tests of SpeedManual, it Forces Motorboat Manual, Attention and Perception, Verbal Intellectual Quotient and Questionnaires ofAnxiety and of Lateral Preference; and two experiments. The dependent variable were cheats of reaction (TR andaccuracy of the answer: successes, errors for confusion of visual field and of identity of stimulus, and omissions. Theywere carried out two experiments of presentation lateralized, one with stimuli of different same physical identity, andthe other one with stimuli of identity categorial with two conditions: Abstract and I sum up.Results: Our results are in the line of the current conception of functional asymmetry of» grade phenomenon» and notof» everything or anything.» In tasks of IF he/she was an advantage of the left visual field. right hemisphere (LVF -RH on the field visual right. left hemisphere (RVF - LH in analysis visoespaciales of alphabetical stimuli, with anadvantage in the resolution of simple tasks of physical identity (IF. In tasks of categorization of verbal content theparticipation of the two hemispheres settles down in these tasks, so much in the times of reaction (TR like in theaccuracy of the answer. A proportional relationship was observed among TR and alone under some conditions of theaccuracy of the answer for concrete stimuli (CS as abstract stimuli (AE. He/she was also correlation between TR andaccuracy of the answer in verbal categorization tasks of presentation lateralitation with tasks of manual speed, of forcemotorboat, and of perception and attention, of verbal intelligence and of anxiety.

  14. EFFECT OF MIRROR VISUAL FEEDBACK ON HAND FUNCTIONS IN CHILDREN WITH HEMIPARESIS

    Directory of Open Access Journals (Sweden)

    Mohammed Ismael Elsepaee

    2016-04-01

    Full Text Available Background: Hemiparetic and hemiplegic cerebral palsy(CP constitute at least a third of all people with CP. Children with hemiparesis are suffering from weak hand muscles and retarded hand use.Mirror therapy is a relatively new approach in rehabilitation used in different neurological disorders. In mirror therapy a mirror is positioned orthogonally in front of the center of the patient’s body. The less-affected (healthy extremity is moved and observed in the mirror. The purpose of this study was to determine the effect of mirror visual feedback on improving hand functions in children with hemiparesis. Methods: Forty children with hemiparesis of both sexes, ranged in age from five to seven years old, participated in this study. They were divided randomly into two groups of equal number (control and study. The control group received a specially designed physical therapy exercise program for four successive weeks while the study group received mirror exercise program in addition to the same program of the control group. Hand functions assessments was done using grasping and object manipulation subtests of Peabody developmental motor scale (PDMS-2. Evaluation was performed pre and post treatment program. Results:There was no significant difference between both groups in the pre-treatment mean values of all measured variables. Also, the results of this study revealed a significant improvement in the scores of the PDMS-2 andin grasp strength of the 2 groups. Post treatment results revealed more improvement in favor of the study group as compared with the control group. Conclusion: Using the mirror visual feedback could help in improving hand functions in children with hemiparesis.

  15. Distribution of mammalian-like melanopsin in cyclostome retinas exhibiting a different extent of visual functions.

    Directory of Open Access Journals (Sweden)

    Lanfang Sun

    Full Text Available Mammals contain 1 melanopsin (Opn4 gene that is expressed in a subset of retinal ganglion cells to serve as a photopigment involved in non-image-forming vision such as photoentrainment of circadian rhythms. In contrast, most nonmammalian vertebrates possess multiple melanopsins that are distributed in various types of retinal cells; however, their functions remain unclear. We previously found that the lamprey has only 1 type of mammalian-like melanopsin gene, which is similar to that observed in mammals. Here we investigated the molecular properties and localization of melanopsin in the lamprey and other cyclostome hagfish retinas, which contribute to visual functions including image-forming vision and mainly to non-image-forming vision, respectively. We isolated 1 type of mammalian-like melanopsin cDNA from the eyes of each species. We showed that the recombinant lamprey melanopsin was a blue light-sensitive pigment and that both the lamprey and hagfish melanopsins caused light-dependent increases in calcium ion concentration in cultured cells in a manner that was similar to that observed for mammalian melanopsins. We observed that melanopsin was distributed in several types of retinal cells, including horizontal cells and ganglion cells, in the lamprey retina, despite the existence of only 1 melanopsin gene in the lamprey. In contrast, melanopsin was almost specifically distributed to retinal ganglion cells in the hagfish retina. Furthermore, we found that the melanopsin-expressing horizontal cells connected to the rhodopsin-containing short photoreceptor cells in the lamprey. Taken together, our findings suggest that in cyclostomes, the global distribution of melanopsin in retinal cells might not be related to the melanopsin gene number but to the extent of retinal contribution to visual function.

  16. VisPort: Web-Based Access to Community-Specific Visualization Functionality [Shedding New Light on Exploding Stars: Visualization for TeraScale Simulation of Neutrino-Driven Supernovae (Final Technical Report)

    Energy Technology Data Exchange (ETDEWEB)

    Baker, M Pauline

    2007-06-30

    The VisPort visualization portal is an experiment in providing Web-based access to visualization functionality from any place and at any time. VisPort adopts a service-oriented architecture to encapsulate visualization functionality and to support remote access. Users employ browser-based client applications to choose data and services, set parameters, and launch visualization jobs. Visualization products typically images or movies are viewed in the user's standard Web browser. VisPort emphasizes visualization solutions customized for specific application communities. Finally, VisPort relies heavily on XML, and introduces the notion of visualization informatics - the formalization and specialization of information related to the process and products of visualization.

  17. 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.

  18. [Retinotopic mapping of the human visual cortex with functional magnetic resonance imaging - basic principles, current developments and ophthalmological perspectives].

    Science.gov (United States)

    Hoffmann, M B; Kaule, F; Grzeschik, R; Behrens-Baumann, W; Wolynski, B

    2011-07-01

    Since its initial introduction in the mid-1990 s, retinotopic mapping of the human visual cortex, based on functional magnetic resonance imaging (fMRI), has contributed greatly to our understanding of the human visual system. Multiple cortical visual field representations have been demonstrated and thus numerous visual areas identified. The organisation of specific areas has been detailed and the impact of pathophysiologies of the visual system on the cortical organisation uncovered. These results are based on investigations at a magnetic field strength of 3 Tesla or less. In a field-strength comparison between 3 and 7 Tesla, it was demonstrated that retinotopic mapping benefits from a magnetic field strength of 7 Tesla. Specifically, the visual areas can be mapped with high spatial resolution for a detailed analysis of the visual field maps. Applications of fMRI-based retinotopic mapping in ophthalmological research hold promise to further our understanding of plasticity in the human visual cortex. This is highlighted by pioneering studies in patients with macular dysfunction or misrouted optic nerves.

  19. MODEL OF STRUCTURAL-FUNCTIONAL ANALYSIS OF VISUALS IN RUSSIAN ABC BOOKS AND PRIMERS OF LATE XIX - EARLY XX CENTURIES

    Directory of Open Access Journals (Sweden)

    Ivan I. Teterin

    2016-01-01

    Full Text Available Today the prevalence of visual information coding determines the changes in the text and extra-textual components of the textbook, the problem affects the placement and number of illustrative material, defines the relationship and interaction of text and image information, focuses on new forms of organization of the learning process. The movement of humanity from the dominant culture of text oriented logos or the spread and adoption of visual forms of information broadcast began at the turn of the XIX and XX centuries. It was during this period in the academic literature visual components acquired independent didactic value. I began to develop a holistic visual range of a school textbook.The visual tutorial series has been the subject of special study for many scientific disciplines. The overall goal of our research is to answer the question. What didactic features were inherent in visual range of textbooks for initial literacy in Russia in the second half of XIX - early XX century, why, how, and how they changed. In this article, we will focus on the issue of allocation of structural components of the visual range of the spectrum and the functions they perform.Offering a model of this analysis, we relied on the development problems of the textbook functions V. Krajewski, V. Beilinson, I. Lerner, V. Bespal'ko and characteristics of the major structural components of the textbook, the proposed D. Zuev, A. Sochor, J. Mickey and others. 

  20. The Mozart effect in biofeedback visual rehabilitation: a case report

    Directory of Open Access Journals (Sweden)

    Salvatore S

    2011-09-01

    Full Text Available Serena Salvatore, Aloisa Librando, Mariacristina Esposito, Enzo M VingoloDepartment of Ophthalmology, University La Sapienza, Polo Pontino, Alfredo Fiorini Hospital, Terracina, ItalyPurpose: To evaluate the usefulness of acoustic biofeedback by means of Mozart’s Sonata for Two Pianos in D Major K. 448 to maintain and/or restore visual performance in a patient with macular pucker and glaucoma.Methods: A 74-year-old patient with open angle glaucoma in both eyes and macular pucker in the right eye (RE underwent visual rehabilitation with acoustic biofeedback by means of the MAIA™ Vision Training Module (Centervue, Padova, Italy 10 minutes each eye once a week for 5 weeks. The patient was asked to move his eyes according to a sound which changed into Mozart’s Sonata for Two Pianos when the patient locked the fixation target.Results: Best-corrected visual acuity improved in his right eye (RE and was stable in the left eye (LE. Fixation stability improved in both eyes, and retinal sensitivity decreased in the RE and improved in the LE. The characteristic of the macular pucker did not change during the training as demonstrated with optical coherence tomography. The patient was very satisfied with the training, as demonstrated by a 25-item questionnaire (National Eye Institute – Visual Functioning Questionnaire, NEI-VFQ-25. The patient’s reading speed and the character size which he was able to read improved in his RE.Conclusion: Music could enhance synaptic plasticity and affect neural learning and fixation training by means of MAIA vision training. Therefore it can improve visual performance in patients with macular pucker, postpone the surgical time, and assure a better quality of life for the patient.Keywords: glaucoma, macular cellophane, music, vision training

  1. Similar alterations in brain function for phonological and semantic processing to visual characters in Chinese dyslexia

    Science.gov (United States)

    Liu, Li; Wang, Wenjing; You, Wenping; Li, Yi; Awati, Neha; Zhao, Xu; Booth, James R.; Peng, Danling

    2014-01-01

    Dyslexia in alphabetic languages has been extensively investigated and suggests a central deficit in orthography to phonology mapping in the left hemisphere. Compared to dyslexia in alphabetic languages, the central deficit for Chinese dyslexia is still unclear. Because of the logographic nature of Chinese characters, some have suggested that Chinese dyslexia should have larger deficits in the semantic system. To investigate this, Chinese children with reading disability (RD) were compared to typically developing (TD) children using functional magnetic resonance imaging (fMRI) on a rhyming judgment task and on a semantic association judgment task. RD children showed less activation for both tasks in right visual (BA18, 19) and left occipito-temporal cortex (BA 37), suggesting a deficit in visuo-orthographic processing. RD children also showed less activation for both tasks in left inferior frontal gyrus (BA44), which additionally showed significant correlations with activation of bilateral visuo-orthographic regions in the RD group, suggesting that the abnormalities in frontal cortex and in posterior visuo-orthographic regions may reflect a deficit in the connection between brain regions. Analyses failed to reveal larger differences between groups for the semantic compared to the rhyming task, suggesting that Chinese dyslexia is similarly impaired in the access to phonology and to semantics from the visual orthography. PMID:22698991

  2. Word-decoding as a function of temporal processing in the visual system.

    Science.gov (United States)

    Holloway, Steven R; Náñez, José E; Seitz, Aaron R

    2013-01-01

    This study explored the relation between visual processing and word-decoding ability in a normal reading population. Forty participants were recruited at Arizona State University. Flicker fusion thresholds were assessed with an optical chopper using the method of limits by a 1-deg diameter green (543 nm) test field. Word decoding was measured using reading-word and nonsense-word decoding tests. A non-linguistic decoding measure was obtained using a computer program that consisted of Landolt C targets randomly presented in four cardinal orientations, at 3-radial distances from a focus point, for eight compass points, in a circular pattern. Participants responded by pressing the arrow key on the keyboard that matched the direction the target was facing. The results show a strong correlation between critical flicker fusion thresholds and scores on the reading-word, nonsense-word, and non-linguistic decoding measures. The data suggests that the functional elements of the visual system involved with temporal modulation and spatial processing may affect the ease with which people read.

  3. Word-decoding as a function of temporal processing in the visual system.

    Directory of Open Access Journals (Sweden)

    Steven R Holloway

    Full Text Available This study explored the relation between visual processing and word-decoding ability in a normal reading population. Forty participants were recruited at Arizona State University. Flicker fusion thresholds were assessed with an optical chopper using the method of limits by a 1-deg diameter green (543 nm test field. Word decoding was measured using reading-word and nonsense-word decoding tests. A non-linguistic decoding measure was obtained using a computer program that consisted of Landolt C targets randomly presented in four cardinal orientations, at 3-radial distances from a focus point, for eight compass points, in a circular pattern. Participants responded by pressing the arrow key on the keyboard that matched the direction the target was facing. The results show a strong correlation between critical flicker fusion thresholds and scores on the reading-word, nonsense-word, and non-linguistic decoding measures. The data suggests that the functional elements of the visual system involved with temporal modulation and spatial processing may affect the ease with which people read.

  4. Influence of ischemia on visual function in patients with branch retinal vein occlusion and macular edema

    Directory of Open Access Journals (Sweden)

    Noma H

    2011-05-01

    Full Text Available Hidetaka Noma¹, Hideharu Funatsu¹, Tatsuya Mimura², Katsunori Shimada³¹Department of Ophthalmology, Yachiyo Medical Center, Tokyo Women's Medical University, Owada-shinden, Chiba, Japan; ²Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan; ³Department of Hygiene and Public Health II, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, JapanAbstract: Visual function and retinal morphology were investigated to elucidate the influence of ischemia in patients with branch retinal vein occlusion (BRVO and macular edema. In 41 consecutive patients with BRVO aged 68.9 ± 10.0 years (22 women and 19 men, the area of capillary nonperfusion was measured by fluorescein angiography. Retinal thickness and retinal volume were measured by optical coherence tomography, and mean retinal sensitivity was calculated for each of 9 macular subfields. Mean visual acuity and macular sensitivity within the central subfield were not significantly correlated with the nonperfused area. However, the macular sensitivity within the central 5 subfields and all 9 subfields showed significant negative correlations with the nonperfused area. Also, macular thickness and volume within all 9 subfields were significantly correlated with the nonperfused area. In conclusion, evaluation of both the fovea and the entire macular region may be important in patients with ischemic BRVO.Keywords: branch retinal vein occlusion, macular edema, macular sensitivity, ischemia

  5. Effects of heavy ions on visual function and electrophysiology of rodents: the ALTEA-MICE project

    Science.gov (United States)

    Sannita, W. G.; Acquaviva, M.; Ball, S. L.; Belli, F.; Bisti, S.; Bidoli, V.; Carozzo, S.; Casolino, M.; Cucinotta, F.; De Pascale, M. P.; Di Fino, L.; Di Marco, S.; Maccarone, R.; Martello, C.; Miller, J.; Narici, L.; Peachey, N. S.; Picozza, P.; Rinaldi, A.; Ruggieri, D.; Saturno, M.; Schardt, D.; Vazquez, M.; Lowenstein, D. (Principal Investigator)

    2004-01-01

    ALTEA-MICE will supplement the ALTEA project on astronauts and provide information on the functional visual impairment possibly induced by heavy ions during prolonged operations in microgravity. Goals of ALTEA-MICE are: (1) to investigate the effects of heavy ions on the visual system of normal and mutant mice with retinal defects; (2) to define reliable experimental conditions for space research; and (3) to develop animal models to study the physiological consequences of space travels on humans. Remotely controlled mouse setup, applied electrophysiological recording methods, remote particle monitoring, and experimental procedures were developed and tested. The project has proved feasible under laboratory-controlled conditions comparable in important aspects to those of astronauts' exposure to particle in space. Experiments are performed at the Brookhaven National Laboratories [BNL] (Upton, NY, USA) and the Gesellschaft fur Schwerionenforschung mbH [GSI]/Biophysik (Darmstadt, FRG) to identify possible electrophysiological changes and/or activation of protective mechanisms in response to pulsed radiation. Offline data analyses are in progress and observations are still anecdotal. Electrophysiological changes after pulsed radiation are within the limits of spontaneous variability under anesthesia, with only indirect evidence of possible retinal/cortical responses. Immunostaining showed changes (e.g. increased expression of FGF2 protein in the outer nuclear layer) suggesting a retinal stress reaction to high-energy particles of potential relevance in space. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  6. [Synergy of vision and extraocular proprioception in the mechanisms of functional plasticity of the primary visual cortex in the kitten].

    Science.gov (United States)

    Trotter, Y; Fregnac, Y; Buisseret, P

    1983-01-01

    In 6 week old dark reared kittens, a visual monocular exposure for 6 hrs. elicits major functional modifications in the primary visual cortex. Most cells become orientation selective and are activated through the open eye only. However, if a unilateral section of the ophthalmic branch of the fifth nerve is performed 1 week before the monocular exposure, these modifications are less pronounced, particularly when carried out on the same side as the open eye. Moreover, if the ophthalmic branch has been cut bilaterally, visual monocular exposure has almost no effect: cortical cells remain non selective to orientation and binocularly activated.

  7. Neural Responses to Visual Food Cues According to Weight Status: A Systematic Review of Functional Magnetic Resonance Imaging Studies

    OpenAIRE

    2014-01-01

    Emerging evidence from recent neuroimaging studies suggests that specific food-related behaviors contribute to the development of obesity. The aim of this review was to report the neural responses to visual food cues, as assessed by functional magnetic resonance imaging (fMRI), in humans of differing weight status. Published studies to 2014 were retrieved and included if they used visual food cues, studied humans >18 years old, reported weight status, and included fMRI outcomes. Sixty studies...

  8. Linear green space visual and functional analysis of the impact on the quality of the streets, sample Keshavarz

    OpenAIRE

    KAZEMIAN, Gholamreza; KHAJEH, Shenay; NADIRI, Maryam

    2015-01-01

    Green spaces as part of the urban fabric by several environmental benefits, social-psychological, economic, aesthetic and functional urban sustainability that leads to stability and coherence to space, quality of life and enhance urban livability. Since human and social interaction is the main street, so the street in terms of visual quality and performance management of green spaces to improve the very important. Descriptive study using a survey of green spaces impact on the visual quality a...

  9. Visual Function and Its Relationship with Severity of Early, and Activity of Neovascular, Age-Related Macular Degeneration

    OpenAIRE

    Loughman, James; Sabour-Pickett, Sarah; Nolan, John M.; Klein, Barbara; Klein, Ron; Beatty, Stephen

    2015-01-01

    Purpose: To investigate the relationship between visual function and severity of early age-related macular degeneration (AMD) and activity of neovascular (nv-) AMD. Methods: The following data was collected from 66 eyes of 66 subjects with early AMD and 47 eyes of 47 subjects with active nv-AMD: corrected distance visual acuity (CDVA); contrast sensitivity (CS); glare disability (GD); and retinotopic ocular sensitivity (ROS) of the central 5° of the retina, by microperimetry. Fundus photog...

  10. [Effects of nootropic agents on visual functions and lacrimal antioxidative activity in patients with primary open-angle glaucoma].

    Science.gov (United States)

    Davydova, N G; Kuznetsova, T P; Borisova, S A; Abdulkadyrova, M Zh

    2006-01-01

    The paper presents the results of an investigation of the effect of the nootropic agents pantogam and nooclerine on visual functions in patients with primary open-angle glaucoma. These agents have been found to have a beneficial effect on the functional activity of the retina and optic nerve, light sensitivity, hemo- and hydrodynamics of the eye.

  11. BIOCHEMISTRY IN THE SPECIALTY IN VISUAL FUNCTION, AND VIRTUAL ENVIRONMENTS IN THE CICS UMA-IPN

    Directory of Open Access Journals (Sweden)

    Blanca Elisa Pérez-Magaña

    2014-07-01

    Full Text Available The higher education and postgraduate in Mexico." delivered at the National Polytechnic Institute is located in a period of constant modification and sustained that has led to the creation of new pedagogical proposals aimed at the promotion of learning emphasizing virtual education. The development of ICT (Information Technologies and Communication in the last few years has favored the emergence and consolidation of degrees, diplomas, Specialties, Master's Degrees among other, using the distance learning based on a web environment. This work analyzes the importance that had the Biochemistry course taught in the specialty of Visual Function in the CICS and UMA that allowed both to the students as the teachers try to virtually eliminate the disadvantages theoretical to traditional teaching. The results obtained in addition to the skills and competences acquired the students were highly successful, and it is hoped to be able to continue implementing such environments in other specialties and master's degrees.

  12. A Multi-facetted Visual Analytics Tool for Exploratory Analysis of Human Brain and Function Datasets.

    Science.gov (United States)

    Angulo, Diego A; Schneider, Cyril; Oliver, James H; Charpak, Nathalie; Hernandez, Jose T

    2016-01-01

    Brain research typically requires large amounts of data from different sources, and often of different nature. The use of different software tools adapted to the nature of each data source can make research work cumbersome and time consuming. It follows that data is not often used to its fullest potential thus limiting exploratory analysis. This paper presents an ancillary software tool called BRAVIZ that integrates interactive visualization with real-time statistical analyses, facilitating access to multi-facetted neuroscience data and automating many cumbersome and error-prone tasks required to explore such data. Rather than relying on abstract numerical indicators, BRAVIZ emphasizes brain images as the main object of the analysis process of individuals or groups. BRAVIZ facilitates exploration of trends or relationships to gain an integrated view of the phenomena studied, thus motivating discovery of new hypotheses. A case study is presented that incorporates brain structure and function outcomes together with different types of clinical data.

  13. Disturbance of visual functions as a result of temporary blinding from low power lasers

    Science.gov (United States)

    Reidenbach, Hans-Dieter

    2010-04-01

    Although it is well-known that dazzle, flash-blindness and afterimages may be caused by bright optical radiation, only sparse quantitative data are available with regard to the effects arising from low power laser products. Indirect effects like temporary blinding might result in serious incidents or even accidents due to the alteration of visual functions like visual acuity, contrast sensitivity and color discrimination. In order to determine the degree and duration of impairment resulting from dazzle, flash-blindness and afterimages, caused by a laser beam, an investigation has been performed with the goal to improve the current knowledge as far as especially the visual acuity recovery duration is concerned. Two different test set-ups were designed and applied in order to determine the afterimage duration and the recovery time for visual acuity after temporary blinding from a laser, respectively. In order to get the desired information a helium-neon laser was mounted on a movable assembly where the respective beam position and direction could be set up on a semicircle. In addition the mount could be inclined in a vertical plane in order to increase the variability of feasible settings. The power was adjusted in several steps in order to investigate the respective dependence of the afterimage. The investigations were relatively time consuming, since re-adaptation of about half an hour was necessary after every exposure in order not to falsify the results. The trials have been done with several volunteers in the laboratory. After the experimental mapping of the local afterimage duration for the various sites on the retina the foveal afterimage duration taf,fv produced by a red laser beam was determined. The investigations have shown a strong dependence on the angle between the line of sight and the beam direction. Besides a maximum of 300 s the dose relationship taf,fv/s ~ 50.6•ln[(P•texp)/μJ] - 13.4 for laser output powers P between 10 μW and 30 μW with

  14. Visual function and vision-related quality of life in presbyopic adult population of Northwestern Nigeria

    Directory of Open Access Journals (Sweden)

    Nasiru Muhammad

    2015-01-01

    Full Text Available Purpose: To determine the impact of uncorrected presbyopia on vision-related quality of life (QoL and visual function (VF among adults 40 years and older in Bungudu local government area (LGA of Zamfara State, Nigeria. Materials and Methods: A population-based cross-sectional study in Bungudu LGA of Zamfara State Nigeria was conducted in 2012. Six-hundred and fifty persons at least 40 years of age were examined using a two-stage cluster random sampling-based on probability proportional to size. Presbyopia was defined as the inability to read N8 at 40 cm in an indoor illumination using LogMAR E-chart. Demographic information comprising of age, sex, occupation, and educational level among others was obtained from a pilot tested VF-14 and modified vision-related QoL questionnaire by trained interviewer. Results: Out Of the 650 subjects enumerated 635 were examined given a response rate of 97.7%. The mean age of participants was 53.59 years (95% confidence interval:52.75%-54.43%. The crude prevalence of presbyopia was 30.4%, (95% CI: 26.8%-34.1%. The mean VF score of persons with presbyopia was 85.09, (95% CI: 83.09%-87.09% and being female was strongly associated with high VF scores (P = 0.003. The VFs most impaired were the ability to read, write, use mobile phones, and thread needles. The higher the degree of presbyopia the lower the mean VF score (P = 0.00. Conclusion: Uncorrected presbyopia is associated with functional visual impairment and reduce QoL especially in the ability to read, write, and usage of mobile cell phones among adults 40 years and older in Bungudu District.

  15. 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.)

  16. Identifying preperimetric functional loss in glaucoma: a blue-on-yellow multifocal visual evoked potentials study.

    Science.gov (United States)

    Arvind, Hemamalini; Graham, Stuart; Leaney, John; Grigg, John; Goldberg, Ivan; Billson, Frank; Klistorner, Alexander

    2009-06-01

    To determine the ability of blue-on-yellow multifocal visual evoked potentials (BonY mfVEP) to identify functional loss in preperimetric glaucoma. Prospective case series. Thirty patients with glaucomatous optic discs and normal standard visual fields. All patients underwent BonY mfVEP, dilated optic disc stereophotography, and optical coherence tomography (Fast RNFL protocol). Optic disc photographs were assessed by 2 independent examiners in a masked fashion. The mfVEP amplitude asymmetry and latency values were analyzed and compared topographically with findings of disc assessment. Average retinal nerve fiber layer (RNFL) thickness, RNFL asymmetry, and sectors with RNFL thinning were compared between patients with and without mfVEP defects. Fourteen (46.7%) patients demonstrated significant abnormality on amplitude asymmetry deviation plots of BonY mfVEP. In all 14 cases, the defect was monocular and corresponded to the eye with the worse disc. In 13 of 14 patients, the defect also corresponded to the location of the worst affected rim. Average RNFL thickness of eyes with mfVEP defects was 81.2+/-9.9 microm, significantly lower than that of patients without defects (90+/-10.5 microm; P = 0.035). Mean asymmetry of RNFL (better minus worse eye) also was significantly higher for patients with mfVEP defects compared with those without such defects (9.0+/-6.4 microm vs. 3.0+/-7 microm; P = 0.03). Average latency of both eyes of glaucomatous patients was delayed compared with that of controls, with no difference in latency between worse and better eyes of glaucoma patients. There was no association of latency delay with either the location of disc changes or mfVEP amplitude defects. Amplitude asymmetry of the BonY mfVEP seems to be a promising tool to identify functional loss in preperimetric glaucoma. Proprietary or commercial disclosure may be found after the references.

  17. Rapid and Objective Assessment of Neural Function in Autism Spectrum Disorder Using Transient Visual Evoked Potentials

    Science.gov (United States)

    Siper, Paige M.; Zemon, Vance; Gordon, James; George-Jones, Julia; Lurie, Stacey; Zweifach, Jessica; Tavassoli, Teresa; Wang, A. Ting; Jamison, Jesslyn; Buxbaum, Joseph D.; Kolevzon, Alexander

    2016-01-01

    Objective There is a critical need to identify biomarkers and objective outcome measures that can be used to understand underlying neural mechanisms in autism spectrum disorder (ASD). Visual evoked potentials (VEPs) offer a noninvasive technique to evaluate the functional integrity of neural mechanisms, specifically visual pathways, while probing for disease pathophysiology. Methods Transient VEPs (tVEPs) were obtained from 96 unmedicated children, including 37 children with ASD, 36 typically developing (TD) children, and 23 unaffected siblings (SIBS). A conventional contrast-reversing checkerboard condition was compared to a novel short-duration condition, which was developed to enable objective data collection from severely affected populations who are often excluded from electroencephalographic (EEG) studies. Results Children with ASD showed significantly smaller amplitudes compared to TD children at two of the earliest critical VEP components, P60-N75 and N75-P100. SIBS showed intermediate responses relative to ASD and TD groups. There were no group differences in response latency. Frequency band analyses indicated significantly weaker responses for the ASD group in bands encompassing gamma-wave activity. Ninety-two percent of children with ASD were able to complete the short-duration condition compared to 68% for the standard condition. Conclusions The current study establishes the utility of a short-duration tVEP test for use in children at varying levels of functioning and describes neural abnormalities in children with idiopathic ASD. Implications for excitatory/inhibitory balance as well as the potential application of VEP for use in clinical trials are discussed. PMID:27716799

  18. Sociocultural materials and visual art: A functional analysis of Nigerian banknotes, 1973–2009

    Directory of Open Access Journals (Sweden)

    Trevor Vermont Morgan

    2016-12-01

    Full Text Available In the past, crude material such as foodstuffs, textile materials, and ornaments (cowrie shells, manillas, and beads served as money across nations and communities. In the time being, forms of monies have totally differed. Modern notes undergo processes of deliberate design, considering forms and imageries. Such imageries and elements included in currency design convey humanistic preoccupations relevant to societies in several ways. And as part of the characteristics, the notes are symbolic, stylistic, and functional to reveal prominent societal ideals as well as experiences of the people. This paper, through historical and analytical approaches, has investigated some of Nigeria’s banknotes from 1973 to 2009 as visual data for producing meaning from viewpoint of art and society. Here, I put forward the analysis of forms and meaning of imageries used in the bank notes designs using iconographic, iconological, functional, and structuralist methods. The paper has underscored naira banknotes as historical documents, archived with certain didactic functions. It has also established the need for routing society’s developments through art practice localized in content and context.

  19. Gross motor function, functional skills and caregiver assistance in children with spastic cerebral palsy (CP) with and without cerebral visual impairment (CVI)

    NARCIS (Netherlands)

    Salavati, M.; Rameckers, E.A.A.; Steenbergen, B.; Schans, C.P. van der

    2014-01-01

    Aim: To determine whether the level of gross motor function and functional skills in children with cerebral palsy (CP) and cerebral visual impairment (CVI) as well as caregiver assistance are lower in comparison with the corresponding group of children experiencing CP without CVI. Method: Data aggre

  20. Gross motor function, functional skills and caregiver assistance in children with spastic cerebral palsy (CP) with and without cerebral visual impairment (CVI)

    NARCIS (Netherlands)

    Salavati, M.; Rameckers, E.A.A.; Steenbergen, B.; Schans, C.P. van der

    2014-01-01

    Aim: To determine whether the level of gross motor function and functional skills in children with cerebral palsy (CP) and cerebral visual impairment (CVI) as well as caregiver assistance are lower in comparison with the corresponding group of children experiencing CP without CVI. Method: Data

  1. Visualization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Evaluates and improves the operational effectiveness of existing and emerging electronic warfare systems. By analyzing and visualizing simulation results...

  2. Functionally Specific Oscillatory Activity Correlates between Visual and Auditory Cortex in the Blind

    Science.gov (United States)

    Schepers, Inga M.; Hipp, Joerg F.; Schneider, Till R.; Roder, Brigitte; Engel, Andreas K.

    2012-01-01

    Many studies have shown that the visual cortex of blind humans is activated in non-visual tasks. However, the electrophysiological signals underlying this cross-modal plasticity are largely unknown. Here, we characterize the neuronal population activity in the visual and auditory cortex of congenitally blind humans and sighted controls in a…

  3. Functionally Specific Oscillatory Activity Correlates between Visual and Auditory Cortex in the Blind

    Science.gov (United States)

    Schepers, Inga M.; Hipp, Joerg F.; Schneider, Till R.; Roder, Brigitte; Engel, Andreas K.

    2012-01-01

    Many studies have shown that the visual cortex of blind humans is activated in non-visual tasks. However, the electrophysiological signals underlying this cross-modal plasticity are largely unknown. Here, we characterize the neuronal population activity in the visual and auditory cortex of congenitally blind humans and sighted controls in a…

  4. Accelerating Scientific Discovery Through Computation and Visualization III. Tight-Binding Wave Functions for Quantum Dots.

    Science.gov (United States)

    Sims, James S; George, William L; Griffin, Terence J; Hagedorn, John G; Hung, Howard K; Kelso, John T; Olano, Marc; Peskin, Adele P; Satterfield, Steven G; Terrill, Judith Devaney; Bryant, Garnett W; Diaz, Jose G

    2008-01-01

    This is the third in a series of articles that describe, through examples, how the Scientific Applications and Visualization Group (SAVG) at NIST has utilized high performance parallel computing, visualization, and machine learning to accelerate scientific discovery. In this article we focus on the use of high performance computing and visualization for simulations of nanotechnology.

  5. Accelerating Scientific Discovery Through Computation and Visualization III. Tight-Binding Wave Functions for Quantum Dots

    OpenAIRE

    2008-01-01

    This is the third in a series of articles that describe, through examples, how the Scientific Applications and Visualization Group (SAVG) at NIST has utilized high performance parallel computing, visualization, and machine learning to accelerate scientific discovery. In this article we focus on the use of high performance computing and visualization for simulations of nanotechnology.

  6. A survey of visual function in an Austrian population of school-age children with reading and writing difficulties

    Directory of Open Access Journals (Sweden)

    McClelland Julie F

    2010-05-01

    Full Text Available Abstract Background To describe and compare visual function measures of two groups of school age children (6-14 years of age attending a specialist eyecare practice in Austria; one group referred to the practice from educational assessment centres diagnosed with reading and writing difficulties and the other, a clinical age-matched control group. Methods Retrospective clinical data from one group of subjects with reading difficulties (n = 825 and a clinical control group of subjects (n = 328 were examined. Statistical analysis was performed to determine whether any differences existed between visual function measures from each group (refractive error, visual acuity, binocular status, accommodative function and reading speed and accuracy. Results Statistical analysis using one way ANOVA demonstrated no differences between the two groups in terms of refractive error and the size or direction of heterophoria at distance (p > 0.05. Using predominately one way ANOVA and chi-square analyses, those subjects in the referred group were statistically more likely to have poorer distance visual acuity, an exophoric deviation at near, a lower amplitude of accommodation, reduced accommodative facility, reduced vergence facility, a reduced near point of convergence, a lower AC/A ratio and a slower reading speed than those in the clinical control group (p Conclusions This study highlights the high proportions of visual function anomalies in a group of children with reading difficulties in an Austrian population. It confirms the importance of a full assessment of binocular visual status in order to detect and remedy these deficits in order to prevent the visual problems continuing to impact upon educational development.

  7. A survey of visual function in an Austrian population of school-age children with reading and writing difficulties

    Science.gov (United States)

    2010-01-01

    Background To describe and compare visual function measures of two groups of school age children (6-14 years of age) attending a specialist eyecare practice in Austria; one group referred to the practice from educational assessment centres diagnosed with reading and writing difficulties and the other, a clinical age-matched control group. Methods Retrospective clinical data from one group of subjects with reading difficulties (n = 825) and a clinical control group of subjects (n = 328) were examined. Statistical analysis was performed to determine whether any differences existed between visual function measures from each group (refractive error, visual acuity, binocular status, accommodative function and reading speed and accuracy). Results Statistical analysis using one way ANOVA demonstrated no differences between the two groups in terms of refractive error and the size or direction of heterophoria at distance (p > 0.05). Using predominately one way ANOVA and chi-square analyses, those subjects in the referred group were statistically more likely to have poorer distance visual acuity, an exophoric deviation at near, a lower amplitude of accommodation, reduced accommodative facility, reduced vergence facility, a reduced near point of convergence, a lower AC/A ratio and a slower reading speed than those in the clinical control group (p < 0.05). Conclusions This study highlights the high proportions of visual function anomalies in a group of children with reading difficulties in an Austrian population. It confirms the importance of a full assessment of binocular visual status in order to detect and remedy these deficits in order to prevent the visual problems continuing to impact upon educational development. PMID:20500851

  8. Dysflective cones: Visual function and cone reflectivity in long-term follow-up of acute bilateral foveolitis

    Directory of Open Access Journals (Sweden)

    Joanna H. Tu

    2017-09-01

    Conclusions and importance: Fundus-referenced visual testing proved useful to identify functional cones despite apparent photoreceptor loss identified using AOSLO and SD-OCT. While AOSLO and SD-OCT appear to be sensitive for the detection of abnormal or absent photoreceptors, changes in photoreceptors that are identified with these imaging tools do not correlate completely with visual function in every patient. Fundus-referenced vision testing is a useful tool to indicate the presence of cones that may be amenable to recovery or response to experimental therapies despite not being visible on confocal AOSLO or SD-OCT images.

  9. Functional Asymmetries Revealed in Visually Guided Saccades: An fMRI Study

    Energy Technology Data Exchange (ETDEWEB)

    Petit, L.; Zago, L.; Vigneau, M.; Crivello, F.; Mazoyer, B.; Mellet, E.; Tzourio-Mazoyer, N. [Centre for Imaging, Neurosciences and Applications to Pathologies, UMR6232 CNRS CEA (France); Mazoyer, B. [Centre Hospitalier Universitaire, Caen (France); Andersson, F. [Institut Federatif de Recherche 135, Imagerie fonctionnelle, Tours (France); Mazoyer, B. [Institut Universitaire de France, Paris (France)

    2009-07-01

    Because eye movements are a fundamental tool for spatial exploration, we hypothesized that the neural bases of these movements in humans should be under right cerebral dominance, as already described for spatial attention. We used functional magnetic resonance imaging in 27 right-handed participants who alternated central fixation with either large or small visually guided saccades (VGS), equally performed in both directions. Hemispheric functional asymmetry was analyzed to identify whether brain regions showing VGS activation elicited hemispheric asymmetries. Hemispheric anatomical asymmetry was also estimated to assess its influence on the VGS functional lateralization. Right asymmetrical activations of a saccadic/attentional system were observed in the lateral frontal eye fields (FEF), the anterior part of the intra-parietal sulcus (aIPS), the posterior third of the superior temporal sulcus (STS), the occipito-temporal junction (MT/V5 area), the middle occipital gyrus, and medially along the calcarine fissure (V1). The present rightward functional asymmetries were not related to differences in gray matter (GM) density/sulci positions between right and left hemispheres in the pre-central, intra-parietal, superior temporal, and extrastriate regions. Only V1 asymmetries were explained for almost 20% of the variance by a difference in the position of the right and left calcarine fissures. Left asymmetrical activations of a saccadic motor system were observed in the medial FEF and in the motor strip eye field along the Rolando sulcus. They were not explained by GM asymmetries. We suggest that the leftward saccadic motor asymmetry is part of a general dominance of the left motor cortex in right-handers, which must include an effect of sighting dominance. Our results demonstrate that, although bilateral by nature, the brain network involved in the execution of VGSs, irrespective of their direction, presented specific right and left asymmetries that were not related to

  10. The PedsQL™ Present Functioning Visual Analogue Scales: preliminary reliability and validity

    Directory of Open Access Journals (Sweden)

    Varni James W

    2006-10-01

    Full Text Available Abstract Background The PedsQL™ Present Functioning Visual Analogue Scales (PedsQL™ VAS were designed as an ecological momentary assessment (EMA instrument to rapidly measure present or at-the-moment functioning in children and adolescents. The PedsQL™ VAS assess child self-report and parent-proxy report of anxiety, sadness, anger, worry, fatigue, and pain utilizing six developmentally appropriate visual analogue scales based on the well-established Varni/Thompson Pediatric Pain Questionnaire (PPQ Pain Intensity VAS format. Methods The six-item PedsQL™ VAS was administered to 70 pediatric patients ages 5–17 and their parents upon admittance to the hospital environment (Time 1: T1 and again two hours later (Time 2: T2. It was hypothesized that the PedsQL™ VAS Emotional Distress Summary Score (anxiety, sadness, anger, worry and the fatigue VAS would demonstrate moderate to large effect size correlations with the PPQ Pain Intensity VAS, and that patient" parent concordance would increase over time. Results Test-retest reliability was demonstrated from T1 to T2 in the large effect size range. Internal consistency reliability was demonstrated for the PedsQL™ VAS Total Symptom Score (patient self-report: T1 alpha = .72, T2 alpha = .80; parent proxy-report: T1 alpha = .80, T2 alpha = .84 and Emotional Distress Summary Score (patient self-report: T1 alpha = .74, T2 alpha = .73; parent proxy-report: T1 alpha = .76, T2 alpha = .81. As hypothesized, the Emotional Distress Summary Score and Fatigue VAS were significantly correlated with the PPQ Pain VAS in the medium to large effect size range, and patient and parent concordance increased from T1 to T2. Conclusion The results demonstrate preliminary test-retest and internal consistency reliability and construct validity of the PedsQL™ Present Functioning VAS instrument for both pediatric patient self-report and parent proxy-report. Further field testing is required to extend these initial

  11. Executive Function, Visual Attention and the Cocktail Party Problem in Musicians and Non-Musicians

    Science.gov (United States)

    Clayton, Kameron K.; Swaminathan, Jayaganesh; Yazdanbakhsh, Arash; Zuk, Jennifer; Patel, Aniruddh D.; Kidd, Gerald

    2016-01-01

    The goal of this study was to investigate how cognitive factors influence performance in a multi-talker, “cocktail-party” like environment in musicians and non-musicians. This was achieved by relating performance in a spatial hearing task to cognitive processing abilities assessed using measures of executive function (EF) and visual attention in musicians and non-musicians. For the spatial hearing task, a speech target was presented simultaneously with two intelligible speech maskers that were either colocated with the target (0° azimuth) or were symmetrically separated from the target in azimuth (at ±15°). EF assessment included measures of cognitive flexibility, inhibition control and auditory working memory. Selective attention was assessed in the visual domain using a multiple object tracking task (MOT). For the MOT task, the observers were required to track target dots (n = 1,2,3,4,5) in the presence of interfering distractor dots. Musicians performed significantly better than non-musicians in the spatial hearing task. For the EF measures, musicians showed better performance on measures of auditory working memory compared to non-musicians. Furthermore, across all individuals, a significant correlation was observed between performance on the spatial hearing task and measures of auditory working memory. This result suggests that individual differences in performance in a cocktail party-like environment may depend in part on cognitive factors such as auditory working memory. Performance in the MOT task did not differ between groups. However, across all individuals, a significant correlation was found between performance in the MOT and spatial hearing tasks. A stepwise multiple regression analysis revealed that musicianship and performance on the MOT task significantly predicted performance on the spatial hearing task. Overall, these findings confirm the relationship between musicianship and cognitive factors including domain-general selective attention and

  12. Radiation therapy for primary carcinoma of the eyelid. Tumor control and visual function

    Energy Technology Data Exchange (ETDEWEB)

    Hata, M.; Koike, I.; Odagiri, K.; Kasuya, T.; Minagawa, Y.; Kaizu, H.; Mukai, Y.; Inoue, T. [Yokohama City Univ. Graduate School of Medicine, Kanagawa (Japan). Dept. of Radiology; Maegawa, J. [Yokohama City Univ. Graduate School of Medicine, Kanagawa (Japan). Dept. of Plastic and Reconstructive Surgery; Kaneko, A. [Yokohama City Univ. Graduate School of Medicine, Kanagawa (Japan). Dept. of Ophthalmology

    2012-12-15

    Background and purpose: Surgical excision remains the standard and most reliable curative treatment for eyelid carcinoma, but frequently causes functional and cosmetic impairment of the eyelid. We therefore investigated the efficacy and safety of radiation therapy in eyelid carcinoma. Patients and methods: Twenty-three patients with primary carcinoma of the eyelid underwent radiation therapy. Sebaceous carcinoma was histologically confirmed in 16 patients, squamous cell carcinoma in 6, and basal cell carcinoma in 1. A total dose of 50-66.6 Gy (median, 60 Gy) was delivered to tumor sites in 18-37 fractions (median, 30 fractions). Results: All but 3 of the 23 patients had survived at a median follow-up period of 49 months. The overall survival and local progression-free rates were 87% and 93% at 2 years, and 80% and 93% at 5 years, respectively. Although radiation-induced cataracts developed in 3 patients, visual acuity in the other patients was relatively well preserved. There were no other therapy-related toxicities of grade 3 or greater. Conclusion: Radiation therapy is safe and effective for patients with primary carcinoma of the eyelid. It appears to contribute to prolonged survival as a result of good tumor control, and it also facilitates functional and cosmetic preservation of the eyelid. (orig.)

  13. Relation between Visual Acuity and Slope of Psychometric Function in Young Adults

    Directory of Open Access Journals (Sweden)

    Tomoki Tokutake

    2011-05-01

    Full Text Available Mita et al. (2010 devised a technique of comparing a visual acuity (VA change in an individual with more accurate VA than conventional VA tests by significant difference examined logarithmic (Log VA ± standard deviation (SD. Using this technique, in this study, we examined a relation between VA and the slope of the psychometric function in normal young subjects. Six occlusion foil conditions were employed (1.0, 0.8, 0.6, 0.4, 0.1 and without the foil under a full refractive correction. Ten normal young adults (22.8 years old on average who have no ophthalmologic disease except ametropia participated in the measurement. The experiment was carried out with the constant method, a series of ten Landolt rings were used and each ring was presented 20 times randomly in a measurement. A 5.6-inch type of liquid crystal display driven by a computer, which has 1,280×800 pixels spatial resolution, was used to present the stimulus. In the normal young adults, the slope of the psychometric function did not change as the VA change systematically, and there was almost no correlation between them (r = −0.103.

  14. Função visual de crianças pseudofácicas por catarata infantil Visual Function in pseuphakic children with Pediatric cataract

    Directory of Open Access Journals (Sweden)

    Patrícia da Rocha Pitta Ferraz

    2009-10-01

    Full Text Available OBJETIVO: O tipo de ambliopia mais grave é o de privação, deste a causa mais comum é a catarata congênita. O objetivo deste estudo foi avaliar a função visual binocular de crianças operadas de julho de 2006 a junho de 2008 por cataratas da infância (congênita ou infantil. MÉTODOS: Todas as crianças possuíam idade acima de 4 anos, operadas em idade tardia. Foram avaliadas 6 crianças e realizados testes de acuidade visual, motilidade ocular extrínseca, testes de Titmus e Luzes de Worth (perto e longe. RESULTADOS: A média da idade do diagnóstico da catarata foi de 5,58 anos e o da primeira cirurgia de 8,83 anos. Cinquenta e 67% das crianças alcançaram acuidade visual pós-operatória maior que 0,4 em olhos direito e esquerdo, respectivamente. Apenas uma criança não apresentou estereopsia e fusão aos testes de função sensorial. Todas as demais apresentaram fusão às luzes de Worth. No teste de Titmus, 2(33,3% apresentaram estereopsia grosseira e 3(50% boa ou ótima. Houve diferença estatísticamente significante (p=0,043 entre as acuidades visuais pré e pós- operatórias entre os olhos. CONCLUSÃO: Assim, neste estudo as crianças portadoras de catarata congênita ou infantil precoce de desenvolvimento lento e de catarata infantil tardia, apresentaram bom prognóstico visual após cirurgia com implante de lente intraocular no mesmo tempo cirúrgico, mesmo em idade avançada.OBJECTIVE: The privation ambliopia is the worst type of all. Among these, the most common cause is congenital cataract.The purpose of this study is to evaluate the visual function of children who had surgery between July 2006 and June 2008 for pediatric cataract. METHODS: All children were above 4 years old and had surgery at advanced age.We evaluated 6 children and submitted them to visual acuity, extrinsic ocular movement,Titmus and Worth lights tests. RESULTS: The mean age at the time of diagnosis was 5,58 years old and at the first surgery was 8

  15. Preserved local but disrupted contextual figure-ground influences in an individual with abnormal function of intermediate visual areas.

    Science.gov (United States)

    Brooks, Joseph L; Gilaie-Dotan, Sharon; Rees, Geraint; Bentin, Shlomo; Driver, Jon

    2012-06-01

    Visual perception depends not only on local stimulus features but also on their relationship to the surrounding stimulus context, as evident in both local and contextual influences on figure-ground segmentation. Intermediate visual areas may play a role in such contextual influences, as we tested here by examining LG, a rare case of developmental visual agnosia. LG has no evident abnormality of brain structure and functional neuroimaging showed relatively normal V1 function, but his intermediate visual areas (V2/V3) function abnormally. We found that contextual influences on figure-ground organization were selectively disrupted in LG, while local sources of figure-ground influences were preserved. Effects of object knowledge and familiarity on figure-ground organization were also significantly diminished. Our results suggest that the mechanisms mediating contextual and familiarity influences on figure-ground organization are dissociable from those mediating local influences on figure-ground assignment. The disruption of contextual processing in intermediate visual areas may play a role in the substantial object recognition difficulties experienced by LG.

  16. [The influence of ocular dominance on monovision--the influence of strength of ocular dominance on visual functions].

    Science.gov (United States)

    Nitta, Marie; Shimizu, Kimiya; Niida, Takahiro

    2007-06-01

    Monovision is a method of correction for presbyopia. We have reported the advantage of conventional monovision (the dominant eye is corrected for distance). In this study, we investigated the influence of interocular imbalance of dominancy on the visual function. Ten healthy subjects without any ophthalmologic disease participated. After cycloplegia, the eyes of the subjects were corrected by soft contact lenses with an artificial pupil (diameter: 3.0mm). The dominant eye was corrected for distance, and the difference in lens power between the lenses was 2.5 D. The subjects were classified into two groups by strength of the imbalance of sensory dominance, which was determined by using binocular rivalry. Binocular visual functions (visual acuity at various distances, contrast sensitivity, near stereoacuity) were compared between the two groups. Subjects with strong imbalance of sensory dominance showed decreased near visual acuity as well as decreased binocular summation of contrast sensitivity at low spatial frequencies. On the other hand, near stereoacuity was not affected by the imbalance of sensory dominance. These results suggest that strong imbalance of sensory dominance interferes with binocular visual functions in monovision. Thus, the evaluation of ocular dominance is crucial for clinical applications of monovision.

  17. Desempenho funcional de crianças com deficiência visual, atendidas no Departamento de Estimulação Visual da Fundação Altino Ventura Functional outcome of visually handicapped children cared for at the Department of Visual Stimulation - "Fundação Altino Ventura"

    Directory of Open Access Journals (Sweden)

    Juliana Malta

    2006-08-01

    Full Text Available OBJETIVO: Traçar o perfil funcional de crianças portadoras de deficiência visual. MÉTODOS: Foram avaliadas 27 crianças. Dezessete com acuidade visual normal (que freqüentavam a Escola Municipal Alto do Maracanã, em Recife, e dez portadoras de deficiência visual (que recebiam estimulação visual no Departamento de Estimulação Visual da Fundação Altino Ventura, Recife. Foi utilizado o teste funcional padrão PEDI. RESULTADOS: As crianças portadoras de deficiência visual apresentaram desempenho significantemente inferior nas áreas de autocuidado e mobilidade que as crianças do grupo controle. CONCLUSÃO: A deficiência visual traz conseqüências limitantes para o desempenho de atividades de autocuidado, locomoção, compreensão, comunicação e tarefas domésticas, na faixa etária estudada.PURPOSE: To analyze the functional outcome of visually handicapped children. METHODS: Twenty-seven children were evaluated using the standard functional PEDI test. Seventeen who attended school at "Escola Municipal Alto do Maracanã", Recife - Pernambuco, Brazil, had normal visual acuity and the other ten had visual handicap, and were cared for at Stimulation Visual Department - "Fundação Altino Ventura", in the same city. RESULTS: The children who had visual handicap showed significantly worse performance in self-care and mobility than normal children. CONCLUSION: Visual handicap may have limited the performance regarding self-care, mobility, understanding, communication, home works, in the studied group.

  18. Alpha-band suppression in the visual word form area as a functional bottleneck to consciousness.

    Science.gov (United States)

    Levy, Jonathan; Vidal, Juan R; Oostenveld, Robert; FitzPatrick, Ian; Démonet, Jean-François; Fries, Pascal

    2013-09-01

    The current state of empirical investigations refers to consciousness as an all-or-none phenomenon. However, a recent theoretical account opens up this perspective by proposing a partial level (between nil and full) of conscious perception. In the well-studied case of single-word reading, short-lived exposure can trigger incomplete word-form recognition wherein letters fall short of forming a whole word in one's conscious perception thereby hindering word-meaning access and report. Hence, the processing from incomplete to complete word-form recognition straightforwardly mirrors a transition from partial to full-blown consciousness. We therefore hypothesized that this putative functional bottleneck to consciousness (i.e. the perceptual boundary between partial and full conscious perception) would emerge at a major key hub region for word-form recognition during reading, namely the left occipito-temporal junction. We applied a real-time staircase procedure and titrated subjective reports at the threshold between partial (letters) and full (whole word) conscious perception. This experimental approach allowed us to collect trials with identical physical stimulation, yet reflecting distinct perceptual experience levels. Oscillatory brain activity was monitored with magnetoencephalography and revealed that the transition from partial-to-full word-form perception was accompanied by alpha-band (7-11 Hz) power suppression in the posterior left occipito-temporal cortex. This modulation of rhythmic activity extended anteriorly towards the visual word form area (VWFA), a region whose selectivity for word-forms in perception is highly debated. The current findings provide electrophysiological evidence for a functional bottleneck to consciousness thereby empirically instantiating a recently proposed partial perspective on consciousness. Moreover, the findings provide an entirely new outlook on the functioning of the VWFA as a late bottleneck to full-blown conscious word

  19. Functional connectivity supporting the selective maintenance of feature-location binding in visual working memory

    Directory of Open Access Journals (Sweden)

    Sachiko eTakahama

    2014-06-01

    Full Text Available Information on an object’s features bound to its location is very important for maintaining object representations in visual working memory. Interactions with dynamic multi-dimensional objects in an external environment require complex cognitive control, including the selective maintenance of feature-location binding. Here, we used event-related functional magnetic resonance imaging to investigate brain activity and functional connectivity related to the maintenance of complex feature-location binding. Participants were required to detect task-relevant changes in feature-location binding between objects defined by color, orientation, and location. We compared a complex binding task requiring complex feature-location binding (color-orientation-location with a simple binding task in which simple feature-location binding, such as color-location, was task-relevant and the other feature was task-irrelevant. Univariate analyses showed that the dorsolateral prefrontal cortex (DLPFC, hippocampus, and frontoparietal network were activated during the maintenance of complex feature-location binding. Functional connectivity analyses indicated cooperation between the inferior precentral sulcus (infPreCS, DLPFC, and hippocampus during the maintenance of complex feature-location binding. In contrast, the connectivity for the spatial updating of simple feature-location binding determined by reanalyzing the data from Takahama et al. (2010 demonstrated that the superior parietal lobule (SPL cooperated with the DLPFC and hippocampus. These results suggest that the connectivity for complex feature-location binding does not simply reflect general memory load and that the DLPFC and hippocampus flexibly modulate the dorsal frontoparietal network, depending on the task requirements, with the infPreCS involved in the maintenance of complex feature-location binding and the SPL involved in the spatial updating of simple feature-location binding.

  20. A method to determine the impact of visual function on lesion detection performance

    OpenAIRE

    Thompson, J. D.; Lança, Carla Costa; Lança, Luís; Hogg, Peter

    2016-01-01

    There are few professions in which visual acuity is as important as it is to radiologists. The diagnostic decision making process is composed of a number of events (detection or observation, interpretation and reporting), where the detection phase is subject to a number of physical and psychological phenomena that are critical to the process. Visual acuity is one phenomenon that has often been overlooked, and there is very little research assessing the impact of reduced visual acuity on diagn...

  1. The Effect of Acupuncture on Visual Function in Patients with Congenital and Acquired Nystagmus

    Directory of Open Access Journals (Sweden)

    Tilo Blechschmidt

    2017-05-01

    Full Text Available Background: The aim of this study is to examine the short-term effect of visual function following acupuncture treatment in patients with congenital idiopathic nystagmus and acquired nystagmus (CIN and AN. Methods: An observational pilot study on six patients with confirmed diagnosis of nystagmus (three CIN and three AN patients (2♀, 4♂; mean age 42.67; SD ± 20.57 y, was performed. Acupuncture treatment was done following a standardized protocol applying needle-acupuncture on the body and the ears. The treatment was scheduled with 10 sessions of 30 min duration over five weeks. To assess the effect of the treatment, we performed before, between, and after acupuncture objective measurement of the BCVA (EDTRS charts, contrast vision (CSV-1000, Vector Vision, nystagmography (Compact Integrated Pupillograph, complemented by evaluation questionnaires. A placebo non-acupuncture control group (Nr: 11, 22 eyes; 8♀, 3♂; mean age: 33.34 y (SD ± 7.33 y was taken for comparison. Results: The results showed that, following acupuncture treatment, CIN and AN patients showed improvement (SD± mean in their binocular BCVA (baseline: 0.45 ± 0.36; between: 0.53 ± 0.34 and post-treatment: 0.51 ± 0.28, and in their monocular contrast sensitivity (baseline: 11.29 ± 12.35; between: 11.43 ± 11.45 and post-treatment: 14.0 ± 12.22. The post-/baseline-difference showed a significant improvement in contrast vision and in BCVA for CIN and AN patients, but not for controls (p = 0.029 and p = 0.007, respectively. The effect of the eye showed also, within CIN and AN, significant values for the examined parameters in the post-/baseline difference (p = 0.004 and p ≤ 0.001. Evaluated only binocularly, the respective between-/baseline and post-/baseline difference in the CIN and AN group showed significant values (p < 0.045. Two AN patients reported reduction of oscillations. Among general subjective symptoms, our patients reported reduction of tiredness and

  2. PanViz: interactive visualization of the structure of functionally annotated pangenomes

    DEFF Research Database (Denmark)

    Pedersen, Thomas Lin; Nookaew, Intawat; Wayne Ussery, David

    2017-01-01

    with gene ontology based navigation of gene groups. Furthermore it allows for rich and complex visual querying of gene groups in the pangenome. PanViz visualizations require no external programs and are easily sharable, allowing for rapid pangenome analyses. PanViz is written entirely in Java......PanViz is a novel, interactive, visualization tool for pangenome analysis. PanViz allows visualization of changes in gene group (groups of similar genes across genomes) classification as different subsets of pangenomes are selected, as well as comparisons of individual genomes to pangenomes...

  3. PanViz: interactive visualization of the structure of functionally annotated pangenomes.

    Science.gov (United States)

    Pedersen, Thomas Lin; Nookaew, Intawat; Wayne Ussery, David; Månsson, Maria

    2017-01-05

    PanViz is a novel, interactive, visualization tool for pangenome analysis. PanViz allows visualization of changes in gene group (groups of similar genes across genomes) classification as different subsets of pangenomes are selected, as well as comparisons of individual genomes to pangenomes with gene ontology based navigation of gene groups. Furthermore it allows for rich and complex visual querying of gene groups in the pangenome. PanViz visualizations require no external programs and are easily sharable, allowing for rapid pangenome analyses.

  4. A functional magnetic resonance imaging investigation of visual hallucinations in the human striate cortex.

    Science.gov (United States)

    Abid, Hina; Ahmad, Fayyaz; Lee, Soo Y; Park, Hyun W; Im, Dongmi; Ahmad, Iftikhar; Chaudhary, Safee U

    2016-11-29

    Human beings frequently experience fear, phobia, migraine and hallucinations, however, the cerebral mechanisms underpinning these conditions remain poorly understood. Towards this goal, in this work, we aim to correlate the human ocular perceptions with visual hallucinations, and map them to their cerebral origins. An fMRI study was performed to examine the visual cortical areas including the striate, parastriate and peristriate cortex in the occipital lobe of the human brain. 24 healthy subjects were enrolled and four visual patterns including hallucination circle (HCC), hallucination fan (HCF), retinotopy circle (RTC) and retinotopy cross (RTX) were used towards registering their impact in the aforementioned visual related areas. One-way analysis of variance was used to evaluate the significance of difference between induced activations. Multinomial regression and and K-means were used to cluster activation patterns in visual areas of the brain. Significant activations were observed in the visual cortex as a result of stimulus presentation. The responses induced by visual stimuli were resolved to Brodmann areas 17, 18 and 19. Activation data clustered into independent and mutually exclusive clusters with HCC registering higher activations as compared to HCF, RTC and RTX. We conclude that small circular objects, in rotation, tend to leave greater hallucinating impressions in the visual region. The similarity between observed activation patterns and those reported in conditions such as epilepsy and visual hallucinations can help elucidate the cortical mechanisms underlying these conditions. Trial Registration 1121_GWJUNG.

  5. 葡萄膜炎的视功能预后%Prognosis of visual function of uveitis

    Institute of Scientific and Technical Information of China (English)

    池滢

    2011-01-01

    葡萄膜炎是造成视功能损害的重要病因之一.视功能的评价手段包括视力、视野、对比敏感度、色觉、视觉电生理等,其中,视力是最直观实用的手段.各种病因所引起的葡萄膜炎视力预后差异较大,炎症的严重程度、炎症部位、并发症不同,对视力的影响程度也不同.视力损害最常见于全葡萄膜炎患者,且年龄较大的全葡萄膜炎患者发生严重视力损害的风险增加,双眼葡萄膜炎患者炎症一般较重且不易控制.在各种病因中,结节病性葡萄膜炎、Behcet病、青少年类风湿性关节炎伴发葡萄膜炎者视力预后较差.葡萄膜炎的并发症也可以直接引起视功能损害,黄斑囊样水肿(CME)是葡萄膜炎最常见的并发症,也是引起葡萄膜炎患者视力损害最常见的原因.葡萄膜炎患者的对比敏感度、视野、视网膜电图检查同样可以遗留异常.就葡萄膜炎的视功能预后及其影响因素进行综述.%Uveitis is one of the leading causes of visual impairment.The method of evaluate to visual function include visual acuity,visual field,contrast sensitivity,color vision and visual electrophysiology.Among these methods,the most direct and common one is visual acuity.The visual outcomes are various because of the differences of cause of disease,severity of inflammation,location of lesion and complications.Visual impairment is most common in panuveitis.The risk of serious visual impairment is increased with aging.Bilateral inflammation is more serious and difficult to cure.Of varied causes of disease,the visual outcomes in sarcoid-related uveitis,Behcet' s disease and juvenile arthritis-related uveitis are poor.The complications of uveitis can cause visual impairment directly as well.Cystoid macular edema is the most common complication of uveitis,and which to bring up to visual impairment.There are abnormalities left in contrast sensitivity,visual field and electroretinogram.This article

  6. Investigation of human visual cortex responses to flickering light using functional near infrared spectroscopy and constrained ICA

    Directory of Open Access Journals (Sweden)

    Nguyen Duc Thang

    2014-11-01

    Full Text Available The human visual sensitivity to the flickering light has been under investigation for decades. The finding of research in this area can contribute to the understanding of human visual system mechanism and visual disorders, and establishing diagnosis and treatment of diseases. The aim of this study is to investigate the effects of the flickering light to the visual cortex by monitoring the hemodynamic responses of the brain with the functional near infrared spectroscopy (fNIRS method. Since the acquired fNIRS signals are affected by physiological factors and measurement artifacts, constrained independent component analysis (cICA was applied to extract the actual fNIRS responses from the obtained data. The experimental results revealed significant changes (p < 0.0001 of the hemodynamic responses of the visual cortex from the baseline when the flickering stimulation was activated. With the uses of cICA, the contrast to noise ratio (CNR, reflecting the contrast of hemodynamic concentration between rest and task, became larger. This indicated the improvement of the fNIRS signals when the noise was eliminated. In subsequent studies, statistical analysis was used to infer the correlation between the fNIRS signals and the visual stimulus. We found that there was a slight decrease of the oxygenated hemoglobin concentration (about 5.69% over four frequencies when the modulation increased. However, the variations of oxy and deoxy-hemoglobin were not statistically significant.

  7. Neuropsychological functions and visual contrast sensitivity in schizophrenia: the potential impact of comorbid posttraumatic stress disorder (PTSD

    Directory of Open Access Journals (Sweden)

    Ibolya eHalasz

    2013-03-01

    Full Text Available Previous studies have revealed a high prevalence of posttraumatic stress disorder (PTSD in patients with other severe mental disorders, including schizophrenia. However, the neuropsychological and psychophysical correlates of comorbid PTSD are less exactly defined. The purpose of the present study was to assess immediate and delayed memory, attention, visuospatial skills, language, and basic visual information processing in patients with schizophrenia with or without PTSD. We recruited 125 patients with schizophrenia and 70 healthy controls matched for visual acuity, age, gender, education, and socioeconomic status. Twenty-one of patients with schizophrenia exhibited comorbid PTSD. We administered the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS and visual contrast sensitivity tasks for low spatial/high temporal frequency (0.3 cycle/degree and 18 Hz and high spatial/low temporal frequency (10 cycles/degree and 1Hz sinusoidal gratings. All patients were clinically stable and received antipsychotic medications. Results revealed that relative to healthy controls, patients with schizophrenia exhibited significant and generalized neuropsychological dysfunctions and reduced visual contrast sensitivity, which was more pronounced at low spatial/high temporal frequency. When we compared schizophrenia patients with and without PTSD, we found that patients with comorbid PTSD displayed lower scores for RBANS attention, immediate and delayed memory, and visuospatial scores. Schizophrenia patients with or without PTSD displayed similar visual contrast sensitivity. In conclusion, comorbid PTSD in schizophrenia may be associated with worse neuropsychological functions, whereas it does not affect basic visual information processing.

  8. Integrated Analysis and Visualization of Group Differences in Structural and Functional Brain Connectivity: Applications in Typical Ageing and Schizophrenia

    NARCIS (Netherlands)

    Langen, C.D.; White, T.; Ikram, M.A.; Vernooij, M.W.; Niessen, W.J.

    2015-01-01

    Structural and functional brain connectivity are increasingly used to identify and analyze group differences in studies of brain disease. This study presents methods to analyze uni- and bi-modal brain connectivity and evaluate their ability to identify differences. Novel visualizations of significan

  9. Emotion Recognition in Faces and the Use of Visual Context in Young People with High-Functioning Autism Spectrum Disorders

    Science.gov (United States)

    Wright, Barry; Clarke, Natalie; Jordan, Jo; Young, Andrew W.; Clarke, Paula; Miles, Jeremy; Nation, Kate; Clarke, Leesa; Williams, Christine

    2008-01-01

    We compared young people with high-functioning autism spectrum disorders (ASDs) with age, sex and IQ matched controls on emotion recognition of faces and pictorial context. Each participant completed two tests of emotion recognition. The first used Ekman series faces. The second used facial expressions in visual context. A control task involved…

  10. Emotion Recognition in Faces and the Use of Visual Context in Young People with High-Functioning Autism Spectrum Disorders

    Science.gov (United States)

    Wright, Barry; Clarke, Natalie; Jordan, Jo; Young, Andrew W.; Clarke, Paula; Miles, Jeremy; Nation, Kate; Clarke, Leesa; Williams, Christine

    2008-01-01

    We compared young people with high-functioning autism spectrum disorders (ASDs) with age, sex and IQ matched controls on emotion recognition of faces and pictorial context. Each participant completed two tests of emotion recognition. The first used Ekman series faces. The second used facial expressions in visual context. A control task involved…

  11. Cortical visual function in the rd12 mouse model of Leber Congenital Amarousis (LCA) after gene replacement therapy to restore retinal function.

    Science.gov (United States)

    Nusinowitz, S; Ridder, W H; Pang, J J; Chang, B; Noorwez, S M; Kaushal, S; Hauswirth, W W; Heckenlively, J R

    2006-10-01

    One eye of rd12 mice received a sub-retinal injection of a vector carrying normal human RPE65 cDNA at post-natal day 18, and at 6- and 13-months of age. Electroretinograms (ERGs) and visual-evoked potentials (VEPs) were recorded to luminance, and to spatially and temporally modulated stimuli to assess the consequences of delayed treatment on visual pathway function. Early treatment resulted in better overall retinal rescue and better rescue of cone-mediated function. VEPs to low temporal frequency luminance modulation were well preserved at all but the oldest treatment age and corresponded to predictions based on the amount of retinal rescue. In contrast, VEPs to high frequency spatially and temporally modulated stimuli were impaired even at the earliest age. These results provide further support that early treatment in human LCA will have the most hope for optimal visual performance.

  12. Resting-state functional connectivity of the nucleus accumbens in auditory and visual hallucinations in schizophrenia.

    Science.gov (United States)

    Rolland, Benjamin; Amad, Ali; Poulet, Emmanuel; Bordet, Régis; Vignaud, Alexandre; Bation, Rémy; Delmaire, Christine; Thomas, Pierre; Cottencin, Olivier; Jardri, Renaud

    2015-01-01

    Both auditory hallucinations (AH) and visual hallucinations may occur in schizophrenia. One of the main hypotheses underlying their occurrence involves the increased activity of the mesolimbic pathway, which links the ventral tegmental area (VTA) and the nucleus accumbens (NAcc). However, the precise contribution of the mesolimbic pathway in hallucinations across various sensory modalities has not yet been explored. We compared the resting-state functional connectivity (rs-FC) of the NAcc among 16 schizophrenia patients with pure AH, 15 with both visuoauditory hallucinations (VAH), and 14 without hallucinations (NoH). A between-group comparison was performed using random-effects ANCOVA (rs-FC of the bilateral NAcc as the dependent variable, groups as the between-subjects factor, age and Positive and Negative Syndrome Scale scores as covariates; q(false discovery rate [FDR]) hallucinations, but the NAcc FC patterns changed with the complexity of these experiences (ie, 0, 1, or 2 sensory modalities), rather than with severity. This might support the aberrant salience hypothesis of schizophrenia. Moreover, these findings suggest that future clinical and neurobiological studies of hallucinations should evaluate not only the global severity of symptoms but also their sensorial features.

  13. Statistical normal values of visual parameters that characterize binocular function in children.

    Science.gov (United States)

    Jiménez, R; Pérez, M A; García, J A; González, M D

    2004-11-01

    A wide range of visual parameters used to evaluate binocular function were evaluated in a paediatric population (1056 subjects aged 6-12 years). Mean values are provided for these ages in optometric tests that directly assess the vergence system, horizontal phorias for near and far vision (measured by a modified version of the Thorington method), negative and positive vergence amplitude for near and far vision (step vergence testing), vergence facility (flippers 8 Delta BI/8 Delta BO), and near-point of convergence (penlight push-up technique and red-lens push-up technique), as well as stimulus accommodative convergence/accommodation ratio and stereoacuity (Randot test) which provide an overall evaluation of the vergence, accommodative and oculomotor systems. A statistical comparison (anova and Bonferroni post hoc test) of these values between ages was performed. The differences, although statistically significant, were not clinically meaningful, and therefore we identified two trends in the behaviour of these parameters. For all parameters, except for vergence facility, we established a single mean reference value for the age range studied. The difference between the means for vergence facility indicated the need to divide the population into two age ranges (6-8 and 8-12 years). This study establishes statistical normal values for these parameters in a paediatric population and their means are a valuable instrument for separating children with binocular anomalies from those with normal binocular vision.

  14. Functional clustering drives encoding improvement in a developing brain network during awake visual learning.

    Directory of Open Access Journals (Sweden)

    Kaspar Podgorski

    2012-01-01

    Full Text Available Sensory experience drives dramatic structural and functional plasticity in developing neurons. However, for single-neuron plasticity to optimally improve whole-network encoding of sensory information, changes must be coordinated between neurons to ensure a full range of stimuli is efficiently represented. Using two-photon calcium imaging to monitor evoked activity in over 100 neurons simultaneously, we investigate network-level changes in the developing Xenopus laevis tectum during visual training with motion stimuli. Training causes stimulus-specific changes in neuronal responses and interactions, resulting in improved population encoding. This plasticity is spatially structured, increasing tuning curve similarity and interactions among nearby neurons, and decreasing interactions among distant neurons. Training does not improve encoding by single clusters of similarly responding neurons, but improves encoding across clusters, indicating coordinated plasticity across the network. NMDA receptor blockade prevents coordinated plasticity, reduces clustering, and abolishes whole-network encoding improvement. We conclude that NMDA receptors support experience-dependent network self-organization, allowing efficient population coding of a diverse range of stimuli.

  15. Brimonidine suppresses loss of retinal neurons and visual function in a murine model of optic neuritis.

    Science.gov (United States)

    Guo, Xiaoli; Namekata, Kazuhiko; Kimura, Atsuko; Noro, Takahiko; Azuchi, Yuriko; Semba, Kentaro; Harada, Chikako; Yoshida, Hiroshi; Mitamura, Yoshinori; Harada, Takayuki

    2015-04-10

    Optic neuritis is inflammation of the optic nerve and is strongly associated with multiple sclerosis (MS), an inflammatory demyelinating syndrome of the central nervous system. It leads to retinal ganglion cell (RGC) death and can cause severe vision loss. Brimonidine (BMD) is a selective α2-adrenergic receptor agonist that is used clinically for the treatment of glaucoma. BMD lowers intraocular pressure, but recent evidence suggests that its therapeutic efficacy may also mediate through mechanisms independent of modulation of intraocular pressure. In this study, we examined the effects of topical administration of BMD on retinal degeneration during optic neuritis in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. EAE was induced with MOG35-55 in C57BL/6J mice and BMD eyedrops were applied daily. In the EAE retina, the number of RGCs was significantly decreased and this effect was suppressed with BMD treatment. Consistent with histological analyses, the visual impairment observed in EAE mice was inhibited with BMD treatment, indicating the functional significance of the neuroprotective effect of BMD. Furthermore, BMD increased the expression level of basic fibroblast growth factor in the EAE retina, particularly in Müller glial cells and RGCs. Our findings suggest that topical administration of BMD may be available for RGC protection during optic neuritis, as well as for glaucoma.

  16. Visual Evoked Potentials as a Readout of Cortical Function in Infants With Tuberous Sclerosis Complex.

    Science.gov (United States)

    Varcin, Kandice J; Nelson, Charles A; Ko, Jordan; Sahin, Mustafa; Wu, Joyce Y; Jeste, Shafali Spurling

    2016-02-01

    Tuberous sclerosis complex is an autosomal dominant genetic disorder that confers a high risk for neurodevelopmental disorders, such as autism spectrum disorder and intellectual disability. Studies have demonstrated specific delays in visual reception skills that may predict the development of autism spectrum disorder and intellectual disability. Based on evidence for alterations in the retinogeniculate pathway in animal models of tuberous sclerosis complex, we asked whether children with tuberous sclerosis complex demonstrate alterations in early visual processing that may undermine the development of higher-level visual behaviors. Pattern-reversal visual evoked potentials were recorded in infants with tuberous sclerosis complex (n = 16) and typically developing infants (n = 18) at 12 months of age. Infants with tuberous sclerosis complex demonstrated remarkably intact visual evoked potentials even within the context of intellectual disability and epilepsy. Infants with tuberous sclerosis complex show intact visual cortical processing, suggesting that delays in visually mediated behaviors in tuberous sclerosis complex may not be rooted in early visual processing deficits.

  17. Data-Driven Visualization and Group Analysis of Multichannel EEG Coherence with Functional Units

    NARCIS (Netherlands)

    Caat, Michael ten; Maurits, Natasha M.; Roerdink, Jos B.T.M.

    2008-01-01

    A typical data- driven visualization of electroencephalography ( EEG) coherence is a graph layout, with vertices representing electrodes and edges representing significant coherences between electrode signals. A drawback of this layout is its visual clutter for multichannel EEG. To reduce clutter, w

  18. How Spatial Abilities and Dynamic Visualizations Interplay When Learning Functional Anatomy with 3D Anatomical Models

    Science.gov (United States)

    Berney, Sandra; Bétrancourt, Mireille; Molinari, Gaëlle; Hoyek, Nady

    2015-01-01

    The emergence of dynamic visualizations of three-dimensional (3D) models in anatomy curricula may be an adequate solution for spatial difficulties encountered with traditional static learning, as they provide direct visualization of change throughout the viewpoints. However, little research has explored the interplay between learning material…

  19. Basic multisensory functions can be acquired after congenital visual pattern deprivation in humans

    DEFF Research Database (Denmark)

    Putzar, L.; Gondan, Matthias; Röder, B.

    2012-01-01

    People treated for bilateral congenital cataracts offer a model to study the influence of visual deprivation in early infancy on visual and multisensory development. We investigated cross-modal integration capabilities in cataract patients using a simple detection task that provided redundant...

  20. The effectiveness of racket-sport intervention on visual perception and executive functions in children with mild intellectual disabilities and borderline intellectual functioning

    Directory of Open Access Journals (Sweden)

    Chen MD

    2015-09-01

    Full Text Available Ming-De Chen,1,2 Hsien-Yu Tsai,1 Chih-Chung Wang,3 Yee-Pay Wuang1,4 1Department of Occupational Therapy, Kaohsiung Medical University, 2Department of Rehabilitation, Kaohsiung Municipal Ta-Tung Hospital, 3Department of Rehabilitation Medicine, 4Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan Background: This study aimed to investigate the effects of table tennis training (TTT versus standard occupational therapy (SOT on visual perception and executive functions in school-age children with mild intellectual disabilities and borderline intellectual functioning.  Subjects and methods: Children (n=91 were randomly assigned to intervention with either SOT (n=46, 20 females, mean age =10.9±3.9 years or TTT (n=45, 21 females, mean age =10.6±3.6 years, while another 41 (18 females, mean age =10.7±4.0 years served as controls. Both the SOT and TTT programs were administered 60 minutes per session, three times a week, for 16 weeks. The Test of Visual Perceptual Skill–third edition (TVPS-3 was used to evaluate visual perception, and executive functions were assessed by the Wisconsin Card Sorting Test 64-card version (WCST-64 and the Stroop test.  Results: At postintervention, the two intervention groups significantly outperformed the control group on all measures of visual perception and executive functions. Participants in the TTT group had significantly greater before–after changes on all measures of the TVPS-3, WCST-64, and the Stroop test compared to the SOT and controls.  Conclusion: Table tennis could be considered a therapy option while treating cognitive/perceptual problems in children with mild intellectual disabilities and borderline intellectual functioning. Implications for clinical professionals and recommendations for further research are discussed. Keywords: visual perception, executive function, table tennis, intellectual disabilities

  1. Integrated Analysis and Visualization of Group Differences in Structural and Functional Brain Connectivity: Applications in Typical Ageing and Schizophrenia.

    Directory of Open Access Journals (Sweden)

    Carolyn D Langen

    Full Text Available Structural and functional brain connectivity are increasingly used to identify and analyze group differences in studies of brain disease. This study presents methods to analyze uni- and bi-modal brain connectivity and evaluate their ability to identify differences. Novel visualizations of significantly different connections comparing multiple metrics are presented. On the global level, "bi-modal comparison plots" show the distribution of uni- and bi-modal group differences and the relationship between structure and function. Differences between brain lobes are visualized using "worm plots". Group differences in connections are examined with an existing visualization, the "connectogram". These visualizations were evaluated in two proof-of-concept studies: (1 middle-aged versus elderly subjects; and (2 patients with schizophrenia versus controls. Each included two measures derived from diffusion weighted images and two from functional magnetic resonance images. The structural measures were minimum cost path between two anatomical regions according to the "Statistical Analysis of Minimum cost path based Structural Connectivity" method and the average fractional anisotropy along the fiber. The functional measures were Pearson's correlation and partial correlation of mean regional time series. The relationship between structure and function was similar in both studies. Uni-modal group differences varied greatly between connectivity types. Group differences were identified in both studies globally, within brain lobes and between regions. In the aging study, minimum cost path was highly effective in identifying group differences on all levels; fractional anisotropy and mean correlation showed smaller differences on the brain lobe and regional levels. In the schizophrenia study, minimum cost path and fractional anisotropy showed differences on the global level and within brain lobes; mean correlation showed small differences on the lobe level. Only

  2. Integrated Analysis and Visualization of Group Differences in Structural and Functional Brain Connectivity: Applications in Typical Ageing and Schizophrenia.

    Science.gov (United States)

    Langen, Carolyn D; White, Tonya; Ikram, M Arfan; Vernooij, Meike W; Niessen, Wiro J

    2015-01-01

    Structural and functional brain connectivity are increasingly used to identify and analyze group differences in studies of brain disease. This study presents methods to analyze uni- and bi-modal brain connectivity and evaluate their ability to identify differences. Novel visualizations of significantly different connections comparing multiple metrics are presented. On the global level, "bi-modal comparison plots" show the distribution of uni- and bi-modal group differences and the relationship between structure and function. Differences between brain lobes are visualized using "worm plots". Group differences in connections are examined with an existing visualization, the "connectogram". These visualizations were evaluated in two proof-of-concept studies: (1) middle-aged versus elderly subjects; and (2) patients with schizophrenia versus controls. Each included two measures derived from diffusion weighted images and two from functional magnetic resonance images. The structural measures were minimum cost path between two anatomical regions according to the "Statistical Analysis of Minimum cost path based Structural Connectivity" method and the average fractional anisotropy along the fiber. The functional measures were Pearson's correlation and partial correlation of mean regional time series. The relationship between structure and function was similar in both studies. Uni-modal group differences varied greatly between connectivity types. Group differences were identified in both studies globally, within brain lobes and between regions. In the aging study, minimum cost path was highly effective in identifying group differences on all levels; fractional anisotropy and mean correlation showed smaller differences on the brain lobe and regional levels. In the schizophrenia study, minimum cost path and fractional anisotropy showed differences on the global level and within brain lobes; mean correlation showed small differences on the lobe level. Only fractional anisotropy

  3. Visual pathway axonal loss in benign multiple sclerosis: a longitudinal study.

    Science.gov (United States)

    Galetta, Kristin M; Graves, Jennifer; Talman, Lauren S; Lile, Deacon J; Frohman, Elliot M; Calabresi, Peter A; Galetta, Steven L; Balcer, Laura J

    2012-06-01

    Benign multiple sclerosis (MS), traditionally defined as Expanded Disability Status Scale (EDSS) score ≤3 and ≥15-year disease duration, is thought to follow a milder clinical course. We determined the extent of visual pathway axonal loss by optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) thickness in a benign MS cohort and examined the relation to vision and quality of life (QOL). In this longitudinal study of vision in MS at 3 academic centers, a subset of patients with EDSS, visual function, OCT, and QOL assessments was analyzed. Low- and high-contrast letter acuity was performed to assess visual function. RNFL thickness was determined using time-domain OCT. QOL scales included the 25-Item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25) and Short Form-36 Health Survey. Among 68 patients (135 eyes) studied longitudinally, 13 (26 eyes) had benign MS using criteria of EDSS score ≤3 and ≥15-year disease duration. Benign MS eyes had as much RNFL thinning (-3.6 μm, P = 0.0008 vs baseline, paired t test) as typical MS eyes (-3.3 μm, P MS (69% vs 33% of eyes). History of ON distinguished benign vs typical MS (P = 0.002) and correlated with RNFL thickness at baseline (P = 0.002) and disease duration (P = 0.03) but not EDSS (P = 0.32, logistic regression). NEI-VFQ-25 scores were also worse for benign MS, accounting for age (75 ± 21 vs 88 ± 11, P = 0.005). Patients with benign MS have RNFL axonal loss that is as marked as that of typical MS and have reduced vision and QOL. While overall neurologic impairment is mild, visual dysfunction, not well captured by the EDSS, accounts for a substantial degree of disability in benign MS.

  4. How art changes your brain: differential effects of visual art production and cognitive art evaluation on functional brain connectivity.

    Science.gov (United States)

    Bolwerk, Anne; Mack-Andrick, Jessica; Lang, Frieder R; Dörfler, Arnd; Maihöfner, Christian

    2014-01-01

    Visual art represents a powerful resource for mental and physical well-being. However, little is known about the underlying effects at a neural level. A critical question is whether visual art production and cognitive art evaluation may have different effects on the functional interplay of the brain's default mode network (DMN). We used fMRI to investigate the DMN of a non-clinical sample of 28 post-retirement adults (63.71 years ±3.52 SD) before (T0) and after (T1) weekly participation in two different 10-week-long art interventions. Participants were randomly assigned to groups stratified by gender and age. In the visual art production group 14 participants actively produced art in an art class. In the cognitive art evaluation group 14 participants cognitively evaluated artwork at a museum. The DMN of both groups was identified by using a seed voxel correlation analysis (SCA) in the posterior cingulated cortex (PCC/preCUN). An analysis of covariance (ANCOVA) was employed to relate fMRI data to psychological resilience which was measured with the brief German counterpart of the Resilience Scale (RS-11). We observed that the visual art production group showed greater spatial improvement in functional connectivity of PCC/preCUN to the frontal and parietal cortices from T0 to T1 than the cognitive art evaluation group. Moreover, the functional connectivity in the visual art production group was related to psychological resilience (i.e., stress resistance) at T1. Our findings are the first to demonstrate the neural effects of visual art production on psychological resilience in adulthood.

  5. Direct and indirect effects of attention and visual function on gait impairment in Parkinson's disease: influence of task and turning.

    Science.gov (United States)

    Stuart, Samuel; Galna, Brook; Delicato, Louise S; Lord, Sue; Rochester, Lynn

    2017-07-01

    Gait impairment is a core feature of Parkinson's disease (PD) which has been linked to cognitive and visual deficits, but interactions between these features are poorly understood. Monitoring saccades allows investigation of real-time cognitive and visual processes and their impact on gait when walking. This study explored: (i) saccade frequency when walking under different attentional manipulations of turning and dual-task; and (ii) direct and indirect relationships between saccades, gait impairment, vision and attention. Saccade frequency (number of fast eye movements per-second) was measured during gait in 60 PD and 40 age-matched control participants using a mobile eye-tracker. Saccade frequency was significantly reduced in PD compared to controls during all conditions. However, saccade frequency increased with a turn and decreased under dual-task for both groups. Poorer attention directly related to saccade frequency, visual function and gait impairment in PD, but not controls. Saccade frequency did not directly relate to gait in PD, but did in controls. Instead, saccade frequency and visual function deficit indirectly impacted gait impairment in PD, which was underpinned by their relationship with attention. In conclusion, our results suggest a vital role for attention with direct and indirect influences on gait impairment in PD. Attention directly impacted saccade frequency, visual function and gait impairment in PD, with connotations for falls. It also underpinned indirect impact of visual and saccadic impairment on gait. Attention therefore represents a key therapeutic target that should be considered in future research. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  6. Relations of low contrast visual acuity, quality of life and multiple sclerosis functional composite: a cross-sectional analysis.

    Science.gov (United States)

    Schinzel, Johann; Zimmermann, Hanna; Paul, Friedemann; Ruprecht, Klemens; Hahn, Katrin; Brandt, Alexander U; Dörr, Jan

    2014-02-20

    Although common and often disabling in multiple sclerosis (MS), visual dysfunction is currently not adequately accounted for in both clinical routine and MS trials. Sloan low contrast letter acuity (SLCLA) is a standardised chart-based measure of visual function particular at low contrast and has been suggested as additional visual component to the Multiple Sclerosis Functional Composite (MSFC). Here, we evaluate the relations between SLCLA, retinal integrity, MSFC, and quality of life (QoL) in MS patients. Cross-sectional analysis of retinal nerve fibre layer (RNFL) thickness, MSFC, SLCLA (2.5% and 1.25% contrast levels), visual evoked potentials, and QoL (Short Form (SF) 36, National Eye Institute Visual Functioning Questionnaire (NEIVFQ)) using baseline data of 92 MS patients from an ongoing prospective longitudinal trial. Relations between RNFL thickness or P100 latency and SLCLA were analysed using generalised estimating equations (GEE) accounting for intra-individual inter-eye dependencies and corrected for age, gender, and history of optic neuritis. Pearson's correlations were used to assess relations between SLCLA, MSFC, and QoL. SLCLA reflected RNFL thickness (p = 0.021) and P100 latency (p = 0.004) and predicted vision-related QoL, reflected by the NEIVFQ39 subscores "general vision" and "near activities" (p QoL reflected by SF36. Implementing SLCLA into MSFC, thus creating a four-dimensional MSFC4, captured aspects of disability reflected by the NEIVFQ39 subscores "general vision" (r = 0.42, p QoL in MS. More importantly, using a prospective cross-sectional approach we provide evidence that extending the MSFC by SLCLA as an additional visual component increases the performance of MSFC to capture MS-related disability. Longitudinal data on the relation between SLCLA, MSFC, and QoL will be available in the near future.

  7. Evaluation of visual functional and morphology change in young patients with idiopathic choroidal neovascularization

    Institute of Scientific and Technical Information of China (English)

    WANG Wen-qiu; WANG Feng-hua; SUN Xiao-dong; LIU Hai-yun; LU Feng-qing; HU Wei-ting; GONG Yuan-yuan; WU Ying; XU Shan; WANG Wei-jun; XU Xun

    2011-01-01

    Background Idiopathic choroidal neovascularization (ICNV) is an uncommon disorder affecting primarily individuals younger than the age of 50 years. In CNV patients, no apparent cause can be determined. This study aimed to evaluate the functional and morphological change of the retina with ICNV in young adults.Methods In this retrospective study, 32 eyes of 32 patients with subfoveal or juxta/extra foveal ICNV had been admitted into the Shanghai First People's Hospital from January 2009 to July 2010. The functional changes were evaluated using the best corrected visual acuity (BCVA) and the microperimetry in the macular area. The morphology changes were evaluated using optical coherence tomography (OCT), the color fundus photography and the fluorescein angiography.Results Seventeen patients with juxta/extra foveal and 15 subfoveal CNV were investigated. The mean logarithm of the minimum angle of resolution (LogMAR) BCVA was 0.39, the mean central retinal thickness (CRT) was 334 urn, and the mean sensitivity (MS) was 11.8 decibels (dB). In the subfoveal group, there was a strong correlation between CRT and BCVA (r=-0.675, F=2.167, P<0.01); as well as that between CRT and MS (r=-0.681, F=22.91, P<0.01). While in the juxta/extra foveal CNV group, the correlation of CRT and BCVA was not significant (r=-0.071, P=1.018, P >0.05); neither was the correlation of CRT and MS (r=-0.142, F=36.54, P>0.05). The microperimetry (MP-1) test revealed 17 (53%) patients with stable fixation, 9 (28%) with relatively unstable and 6 (19%) with unstable fixation. Fixation stability correlated positively with sensitivity in the central 2° diameter area (r=0.380, F=3.213, P <0.05) and the duration of symptoms (r=0.401, F=7.933, P<0.05).Conclusions ICNV was associated with reduced total MS, unstable fixation and eccentric fixation. These findings emphasized functional change in ICNV is beyond the BCVA and regular morphology change, which provided additional information of

  8. Flash visual evoked potential monitoring of optic tract function during macroelectrode-based pallidotomy.

    Science.gov (United States)

    Bonaroti, E A; Rose, R D; Kondziolka, D; Baser, S; Lunsford, L D

    1997-03-15

    Posteroventral pallidotomy (PVP) has received renewed interest as an ablative procedure for the symptomatic treatment of Parkinson's disease. In previous reports, the proximity of the optic tract to the lesion target in the globus pallidus internus has resulted in the occurrence of visual field deficits in as much as 14% of patients. The authors have used intraoperative visual evoked potentials (VEPs) during PVP to reduce this risk. All procedures were performed in awake patients. Flash stimuli were delivered to each eye via fiberoptic sources. Baseline flash VEPs were recorded at O1/Cz (left visual cortex to vertex), Oz/Cz (midline visual cortex to vertex), and O2/Cz (right visual cortex to vertex) for OS, OU, and OD stimulation. Epochs were acquired before and after localization, after macroelectrode stimulation, after temporary thermal lesioning, and after permanent thermal lesioning. Forty-seven patients underwent a total of 59 procedures. Visual evoked potentials were recorded reproducibly in all patients. In 11 procedures, VEP changes were reported, including six amplitude changes (10-80%), six latency shifts (3-10 msec), and one report of "variability." In four procedures, VEP changes prompted a change in target coordinates. One false-positive and one false-negative VEP change were encountered. The only confirmed visual deficit was a superior quadrantanopsia, present on formal fields, but clinically asymptomatic. The authors conclude that VEPs may be useful for procedures performed in the awake patient because of the lack of anesthetic-induced variability. The 1.7% visual morbidity reported here (one in 59 patients) compares favorably with other series using microelectrodes. Visual evoked potentials may be a useful monitoring technique to reduce the incidence of clinically significant visual morbidity during pallidotomy, especially during formal lesioning of the ventral pallidum adjacent to the optic tract.

  9. The Hybrid Programming Technique Of Calling MATLAB Library Functions From Visual C++%Visual C++调用MATLAB函数库的混合编程技术

    Institute of Scientific and Technical Information of China (English)

    徐治

    2015-01-01

    The Visual C++ and MATLAB hybrid programming technique uses VC++ as the powerful software development tool, and directly calls the immense MATLAB algorithm function library while implementing a sophisti-cated algorithm. This approach can achieve the complementation of merits and greatly reduce the coding time of so-phisticated algorithm. This paper introduces the principle of hybrid programming, then details the MATLAB compiler based techniques of coding and project configuration which calls MATLAB function library from VC++.%Visual C++与MATLAB的混合编程技术是以VC++作为强有力的软件开发工具,而在实现复杂算法时则直接调用MATLAB涵盖很广的算法函数库。这种方式可以做到优势互补,大大减少复杂算法的编码时间。本文介绍了混合编程的基本原理,并详细介绍了基于MATLAB编译器的VC++调用MATLAB函数库的代码编写及项目配置等方面的技术。

  10. Effects on visual functions during tasks of object handling in virtual environment with a head mounted display.

    Science.gov (United States)

    Kawara, T; Ohmi, M; Yoshizawa, T

    1996-11-01

    This study examined the effects on visual functions of a prolonged handling task within the helmet-mounted display environment. Both version eye movement and accommodative response became gradually slower during the 40-min task. Although delayed presentation of display after head movement noticeably worsened both visual responses, presentation delay after hand movement did not significantly change the sluggishness of responses. Therefore it is suggested that decreasing time delay after head movement is a more important factor in order to improve human performance of handling tasks within the HMD environment.

  11. Functional and laminar dissociations between muscarinic and nicotinic cholinergic neuromodulation in the tree shrew primary visual cortex.

    Science.gov (United States)

    Bhattacharyya, Anwesha; Bießmann, Felix; Veit, Julia; Kretz, Robert; Rainer, Gregor

    2012-04-01

    Acetylcholine is an important neuromodulator involved in cognitive function. The impact of cholinergic neuromodulation on computations within the cortical microcircuit is not well understood. Here we investigate the effects of layer-specific cholinergic drug application in the tree shrew primary visual cortex during visual stimulation with drifting grating stimuli of varying contrast and orientation. We describe differences between muscarinic and nicotinic cholinergic effects in terms of both the layer of cortex and the attribute of visual representation. Nicotinic receptor activation enhanced the contrast response in the granular input layer of the cortex, while tending to reduce neural selectivity for orientation across all cortical layers. Muscarinic activation modestly enhanced the contrast response across cortical layers, and tended to improve orientation tuning. This resulted in highest orientation selectivity in the supra- and infragranular layers, where orientation selectivity was already greatest in the absence of pharmacological stimulation. Our results indicate that laminar position plays a crucial part in functional consequences of cholinergic stimulation, consistent with the differential distribution of cholinergic receptors. Nicotinic receptors function to enhance sensory representations arriving in the cortex, whereas muscarinic receptors act to boost the cortical computation of orientation tuning. Our findings suggest close homology between cholinergic mechanisms in tree shrew and primate visual cortices.

  12. Ocular status and functional adaptation of visually challenged children of a special school in Oman

    Directory of Open Access Journals (Sweden)

    Rajiv Khandekar

    2011-01-01

    Full Text Available Introduction : We assessed the ocular status and visual adaptation among children studying at a school for visually disabled children in Muscat, Oman. Materials and Methods : This descriptive study was conducted in 2009-2010. We assessed the visual and ocular status of the participants. They were interviewed to elicit the past history of eye problems and management. They also expressed their visual adaptation in their ′day-to-day′ life, and their ambitions. Result : We examined and interviewed 47 participants (29 male and 18 female. The mean age of the participants was 19.7 years (Standard deviation 5.9 years. Twenty-six of them were blind since birth. Phthisical eyes, disfigured eyes and anophthalmic sockets were noted in 19, 58, and six eyes of participants. Twenty-six (55.5% participants had visual disabilities due to genetic causes, since birth. In 13 participants, further investigations were needed to confirm diagnosis and determine further management After low vision training, 13 participants with residual vision could be integrated in the school with normal children. One participant was recommended stem cell treatment for visual restoration. Five children were advised reconstructive orbital surgery. The participants were not keen to use a white cane for mobility. Some participants, 16 / 28 (57%, with absolute blindness, were not able to read the Braille language. Singing and playing music were not very well-accepted hobbies among the participants. Nineteen participants were keen to become teachers. Conclusions : Children with visual disabilities need to be periodically assessed. The underlying causes of visual disabilities should be further explored to facilitate prevention and genetic counseling. Participants had visual adaptation for daily living and had ambitions for the future.

  13. Diabetes-induced impairment in visual function in mice: contributions of p38 MAPK, rage, leukocytes, and aldose reductase.

    Science.gov (United States)

    Lee, Chieh Allen; Li, Guangyuan; Patel, Mansi D; Petrash, J Mark; Benetz, Beth Ann; Veenstra, Alex; Amengual, Jaume; von Lintig, Johannes; Burant, Christopher J; Tang, Johnny; Kern, Timothy S

    2014-05-02

    Visual function is impaired in diabetes, but molecular causes of this dysfunction are not clear. We assessed effects of diabetes on visual psychophysics in mice, and tested the effect of therapeutic approaches reported previously to inhibit vascular lesions of the retinopathy. We used the optokinetic test to assess contrast sensitivity and spatial frequency threshold in diabetic C57Bl/6J mice and age-matched nondiabetic controls between 2 and 10 months of diabetes. Contributions of p38 MAP kinase (MAPK), receptor for advanced glycation end products (RAGE), leukocytes, and aldose reductase (AR) to the defect in contrast sensitivity were investigated. Cataract, a potential contributor to reductions in vision, was scored. Diabetes of 2 months' duration impaired contrast sensitivity and spatial frequency threshold in mice. The defect in contrast sensitivity persisted for at least 10 months, and cataract did not account for this impairment. Diabetic mice deficient in AR were protected significantly from development of the diabetes-induced defects in contrast sensitivity and spatial frequency threshold. In contrast, pharmacologic inhibition of p38 MAPK or RAGE, or deletion of inducible nitrous oxide synthase (iNOS) from bone marrow-derived cells did not protect the visual function in diabetes. Diabetes reduces spatial frequency threshold and contrast sensitivity in mice, and the mechanism leading to development of these defects involves AR. The mechanism by which AR contributes to the diabetes-induced defect in visual function can be probed by identifying which molecular abnormalities are corrected by AR deletion, but not other therapies that do not correct the defect in visual function.

  14. Basic multisensory functions can be acquired after congenital visual pattern deprivation in humans.

    Science.gov (United States)

    Putzar, Lisa; Gondan, Matthias; Röder, Brigitte

    2012-01-01

    People treated for bilateral congenital cataracts offer a model to study the influence of visual deprivation in early infancy on visual and multisensory development. We investigated cross-modal integration capabilities in cataract patients using a simple detection task that provided redundant information to two different senses. In both patients and controls, redundancy gains were consistent with coactivation models, indicating an integrated processing of modality-specific information. This finding is in contrast with recent studies showing impaired higher-level multisensory interactions in cataract patients. The present results suggest that basic cross-modal integrative processes for simple short stimuli do not depend on visual and/or crossmodal input since birth.

  15. [Functional state of the visual analyzer in the conditions of the use of traditional and LED light sources].

    Science.gov (United States)

    Kaptsov, V A; Sosunov, N N; Shishchenko, I I; Viktorov, V S; Tulushev, V N; Deynego, V N; Bukhareva, E A; Murashova, M A; Shishchenko, A A

    2014-01-01

    There was performed the experimental work on the study of the possibility of the application of LED lighting (LED light sources) in rail transport for traffic safety in related professions. Results of 4 series of studies involving 10 volunteers for the study and a comparative evaluation of the functional state of the visual analyzer, the general functional state and mental capacity under the performing the simulated operator activity in conditions of traditional light sources (incandescent, fluorescent lamp) and the new LED (LED lamp, LED panel) light sources have revealed changes in the negative direction. This was pronounced in a some decrease of functional stability to color discrimination between green and red cone signals, as well as an increase in response time in complex visual--motor response and significant reduction in readiness for emergency action of examinees.

  16. Psychophysical measures of visual function and everyday perceptual experience in a case of congenital stationary night blindness

    Directory of Open Access Journals (Sweden)

    Cammack J

    2016-08-01

    Full Text Available Jocelyn Cammack,1 John Whight,2 Vinette Cross,3 Andrew T Rider,1 Andrew R Webster,1,2 Andrew Stockman1 1Department of Visual Neuroscience, UCL Institute of Ophthalmology, 2Moorfields Eye Hospital, London, 3Centre for Health and Social Care Improvement, University of Wolverhampton, Wolverhampton, UK Abstract: An appreciation of the relation between laboratory measures of visual deficit and everyday perceptual experience is fundamental to understanding the impact of a visual condition on patients and so to a fuller characterization of the disorder. This study aims to understand better the interpretative processes by which modified sensory information is perceived by a patient with congenital stationary night blindness and the adaptive strategies that are devised to deal with their measurable visual loss. Psychophysical measurements of temporal resolution, spectral sensitivity, and color discrimination were conducted on a 78-year-old male patient with the condition, who was also interviewed at length about the ways in which his diagnosis affected his daily life. Narrative analysis was employed to identify the relation between his subjective perceptual experiences and functional deficits in identifiable components of the visual system. Psychophysical measurements indicated a complete lack of rod perception and substantially reduced cone sensitivity. Two particular effects of this visual loss emerged during interviews: 1 the development of navigational techniques that relied on light reflections and point sources of light and 2 a reluctance to disclose the extent of visual loss and resulting lifelong psychosocial consequences. This study demonstrates the valuable complementary role that rich descriptive patient testimony can play, in conjunction with laboratory and clinical measurements, in more fully characterizing a disorder and in reaching a more complete understanding of the experience of vision loss. It also evidences the particular

  17. Design strategies and functionality of the Visual Interface for Virtual Interaction Development (VIVID) tool

    Science.gov (United States)

    Nguyen, Lac; Kenney, Patrick J.

    1993-01-01

    Development of interactive virtual environments (VE) has typically consisted of three primary activities: model (object) development, model relationship tree development, and environment behavior definition and coding. The model and relationship tree development activities are accomplished with a variety of well-established graphic library (GL) based programs - most utilizing graphical user interfaces (GUI) with point-and-click interactions. Because of this GUI format, little programming expertise on the part of the developer is necessary to create the 3D graphical models or to establish interrelationships between the models. However, the third VE development activity, environment behavior definition and coding, has generally required the greatest amount of time and programmer expertise. Behaviors, characteristics, and interactions between objects and the user within a VE must be defined via command line C coding prior to rendering the environment scenes. In an effort to simplify this environment behavior definition phase for non-programmers, and to provide easy access to model and tree tools, a graphical interface and development tool has been created. The principal thrust of this research is to effect rapid development and prototyping of virtual environments. This presentation will discuss the 'Visual Interface for Virtual Interaction Development' (VIVID) tool; an X-Windows based system employing drop-down menus for user selection of program access, models, and trees, behavior editing, and code generation. Examples of these selection will be highlighted in this presentation, as will the currently available program interfaces. The functionality of this tool allows non-programming users access to all facets of VE development while providing experienced programmers with a collection of pre-coded behaviors. In conjunction with its existing, interfaces and predefined suite of behaviors, future development plans for VIVID will be described. These include incorporation

  18. Increased amygdala and visual cortex activity and functional connectivity towards stimulus novelty is associated with state anxiety.

    Directory of Open Access Journals (Sweden)

    Olga T Ousdal

    Full Text Available Novel stimuli often require a rapid reallocation of sensory processing resources to determine the significance of the event, and the appropriate behavioral response. Both the amygdala and the visual cortex are central elements of the neural circuitry responding to novelty, demonstrating increased activity to new as compared to highly familiarized stimuli. Further, these brain areas are intimately connected, and thus the amygdala may be a key region for directing sensory processing resources to novel events. Although knowledge regarding the neurocircuit of novelty detection is gradually increasing, we still lack a basic understanding of the conditions that are necessary and sufficient for novelty-specific responses in human amygdala and the visual cortices, and if these brain areas interact during detection of novelty. In the present study, we investigated the response of amygdala and the visual cortex to novelty, by comparing functional MRI activity between 1st and 2nd time presentation of a series of emotional faces in an event-related task. We observed a significant decrease in amygdala and visual cortex activity already after a single stimulus exposure. Interestingly, this decrease in responsiveness was less for subjects with a high score on state anxiety. Further, novel faces stimuli were associated with a relative increase in the functional coupling between the amygdala and the inferior occipital gyrus (BA 18. Thus, we suggest that amygdala is involved in fast sensory boosting that may be important for attention reallocation to novel events, and that the strength of this response depends on individual state anxiety.

  19. ProViz-a web-based visualization tool to investigate the functional and evolutionary features of protein sequences.

    Science.gov (United States)

    Jehl, Peter; Manguy, Jean; Shields, Denis C; Higgins, Desmond G; Davey, Norman E

    2016-07-01

    Low-throughput experiments and high-throughput proteomic and genomic analyses have created enormous quantities of data that can be used to explore protein function and evolution. The ability to consolidate these data into an informative and intuitive format is vital to our capacity to comprehend these distinct but complementary sources of information. However, existing tools to visualize protein-related data are restricted by their presentation, sources of information, functionality or accessibility. We introduce ProViz, a powerful browser-based tool to aid biologists in building hypotheses and designing experiments by simplifying the analysis of functional and evolutionary features of proteins. Feature information is retrieved in an automated manner from resources describing protein modular architecture, post-translational modification, structure, sequence variation and experimental characterization of functional regions. These features are mapped to evolutionary information from precomputed multiple sequence alignments. Data are displayed in an interactive and information-rich yet intuitive visualization, accessible through a simple protein search interface. This allows users with limited bioinformatic skills to rapidly access data pertinent to their research. Visualizations can be further customized with user-defined data either manually or using a REST API. ProViz is available at http://proviz.ucd.ie/.

  20. Ethanol consumption impairs vestibulo-ocular reflex function measured by the video head impulse test and dynamic visual acuity.

    Science.gov (United States)

    Roth, Thomas N; Weber, Konrad P; Wettstein, Vincent G; Marks, Guy B; Rosengren, Sally M; Hegemann, Stefan C A

    2014-01-01

    Ethanol affects many parts of the nervous system, from the periphery to higher cognitive functions. Due to the established effects of ethanol on vestibular and oculomotor function, we wished to examine its effect on two new tests of the vestibulo-ocular reflex (VOR): the video head impulse test (vHIT) and dynamic visual acuity (DVA). We tested eight healthy subjects with no history of vestibular disease after consumption of standardized drinks of 40% ethanol. We used a repeated measures design to track vestibular function over multiple rounds of ethanol consumption up to a maximum breath alcohol concentration (BrAC) of 1.38 per mil. All tests were normal at baseline. VOR gain measured by vHIT decreased by 25% at the highest BrAC level tested in each subject. Catch-up saccades were negligible at baseline and increased in number and size with increasing ethanol consumption (from 0.13° to 1.43° cumulative amplitude per trial). DVA scores increased by 86% indicating a deterioration of acuity, while static visual acuity (SVA) remained unchanged. Ethanol consumption systematically impaired the VOR evoked by high-acceleration head impulses and led to a functional loss of visual acuity during head movement.

  1. Functional interaction between right parietal and bilateral frontal cortices during visual search tasks revealed using functional magnetic imaging and transcranial direct current stimulation.

    Directory of Open Access Journals (Sweden)

    Amanda Ellison

    Full Text Available The existence of a network of brain regions which are activated when one undertakes a difficult visual search task is well established. Two primary nodes on this network are right posterior parietal cortex (rPPC and right frontal eye fields. Both have been shown to be involved in the orientation of attention, but the contingency that the activity of one of these areas has on the other is less clear. We sought to investigate this question by using transcranial direct current stimulation (tDCS to selectively decrease activity in rPPC and then asking participants to perform a visual search task whilst undergoing functional magnetic resonance imaging. Comparison with a condition in which sham tDCS was applied revealed that cathodal tDCS over rPPC causes a selective bilateral decrease in frontal activity when performing a visual search task. This result demonstrates for the first time that premotor regions within the frontal lobe and rPPC are not only necessary to carry out a visual search task, but that they work together to bring about normal function.

  2. [The effect of parenteral citicoline on visual functions and life quality of patients with primary open-angle glaucoma].

    Science.gov (United States)

    Frolov, M A; Gonchar, P A; Barashkov, V I; Kumar, V; Morozova, N S; Frolov, A M; Kazakova, K A

    2011-01-01

    The effect of nootropic drug citicoline on visual functions, perimetric indexes of static automated perimetry, morphometric characteristics of retinal tomography and life quality of patients with primary open-angle glaucoma (POAG) stage I-III and normalized intraocular pressure (IOP) was studied. 40 patients aged 46-78 years old with POAG stage I-III and normalized IOP were treated with citicoline. Among them there were 24 female and 16 male. The patients were divided into 2 equal groups--experimental and control. Patients of both groups were treated with intravenous citicoline for 10 days. The dose of citicoline in experimental group was 1000 mg/day, in control--500 mg/day. After treatment in both groups visual functions, perimetric indexes of static automated perimetry, morphometric characteristics of retinal tomography and life quality showed improvement. Citicoline has significant neuroprotective effect preventing apoptosis.

  3. Functional dissociation between action and perception of object shape in developmental visual object agnosia.

    Science.gov (United States)

    Freud, Erez; Ganel, Tzvi; Avidan, Galia; Gilaie-Dotan, Sharon

    2016-03-01

    According to the two visual systems model, the cortical visual system is segregated into a ventral pathway mediating object recognition, and a dorsal pathway mediating visuomotor control. In the present study we examined whether the visual control of action could develop normally even when visual perceptual abilities are compromised from early childhood onward. Using his fingers, LG, an individual with a rare developmental visual object agnosia, manually estimated (perceptual condition) the width of blocks that varied in width and length (but not in overall size), or simply picked them up across their width (grasping condition). LG's perceptual sensitivity to target width was profoundly impaired in the manual estimation task compared to matched controls. In contrast, the sensitivity to object shape during grasping, as measured by maximum grip aperture (MGA), the time to reach the MGA, the reaction time and the total movement time were all normal in LG. Further analysis, however, revealed that LG's sensitivity to object shape during grasping emerged at a later time stage during the movement compared to controls. Taken together, these results demonstrate a dissociation between action and perception of object shape, and also point to a distinction between different stages of the grasping movement, namely planning versus online control. Moreover, the present study implies that visuomotor abilities can develop normally even when perceptual abilities developed in a profoundly impaired fashion. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. The effect of learning on the function of monkey extrastriate visual cortex.

    Directory of Open Access Journals (Sweden)

    Gregor Rainer

    2004-02-01

    Full Text Available One of the most remarkable capabilities of the adult brain is its ability to learn and continuously adapt to an ever-changing environment. While many studies have documented how learning improves the perception and identification of visual stimuli, relatively little is known about how it modifies the underlying neural mechanisms. We trained monkeys to identify natural images that were degraded by interpolation with visual noise. We found that learning led to an improvement in monkeys' ability to identify these indeterminate visual stimuli. We link this behavioral improvement to a learning-dependent increase in the amount of information communicated by V4 neurons. This increase was mediated by a specific enhancement in neural activity. Our results reveal a mechanism by which learning increases the amount of information that V4 neurons are able to extract from the visual environment. This suggests that V4 plays a key role in resolving indeterminate visual inputs by coordinated interaction between bottom-up and top-down processing streams.

  5. Integrated Analysis and Visualization of Group Differences in Structural and Functional Brain Connectivity: Applications in Typical Ageing and Schizophrenia

    OpenAIRE

    Langen, Carolyn D.; Tonya White; Arfan Ikram, M.; Vernooij, Meike W.; Niessen, Wiro J.

    2015-01-01

    Structural and functional brain connectivity are increasingly used to identify and analyze group differences in studies of brain disease. This study presents methods to analyze uni- and bi-modal brain connectivity and evaluate their ability to identify differences. Novel visualizations of significantly different connections comparing multiple metrics are presented. On the global level, "bi-modal comparison plots" show the distribution of uni- and bi-modal group differences and the relationshi...

  6. Refractive error and visual functions in children with special needs compared with the first grade school students in Oman

    Directory of Open Access Journals (Sweden)

    Vora Urmi

    2010-01-01

    Full Text Available Background: We evaluated the refractive status and visual function of children with special needs (other handicap in 2010 and compared them with healthy 1 st grade school students in Oman. Materials and Methods: This was a cohort study. Optometrists recorded vision using a logarithm of minimum angle of resolution (LogMAR chart. Preferential looking method was used for testing 31 children. Cycloplegic refraction was performed on all children. Contrast sensitivity was tested using 2.5%, 10%, and 100% contrast charts. Ocular movement, alignment, and anterior segment were also assessed. A pediatrician reviewed the health records of all the children at the time of their enrollment in this study to determine if the child had been diagnosed with a systemic condition or syndromes. The visual functions were assessed by study investigators. We estimated the rates and the risk of different visual function defects in children with special needs. Result: The prevalence of refractive error in 70 children (4.7 ± 0.8 years with special needs (group 1 and 175 normal healthy first grade students (group 2 were 58.5% and 2.9%, respectively. The risk of refractive error was significantly higher in children with special needs [relative risk, 48.1 (95% confidence interval, 17.54-131.8]. Hyperopia (>1.00 D, myopia (≥ 1.00D and astigmatism (≥ ±1.00 D were found in 18.6%, 24.3%, and 27.1%, respectively, in group 1. Six children in this group had defective near vision. Sixteen (80% children with Down syndrome had refractive error. Seven (50% children with developmental disorder showed decreased contrast sensitivity. Conclusion: Prevalence of uncorrected refractive error was much higher in children with special needs. Prevalence of strabismus, nystagmus, and reduced contrast sensitivity was also higher in children with special needs. Early vision screening, visual function assessment, correction of refractive error, and frequent follow-up are recommended.

  7. Progress on animal visual function testing and its application in visual function study%动物视觉功能检测的研究进展及其在动物视觉功能研究中的应用

    Institute of Scientific and Technical Information of China (English)

    张作明

    2015-01-01

    Human obtain the outside information mainly from the visual system which is important in human work and life.To improve or recover visual function is the most important indicator in clinical treatment,and visual function testing has special meaning in ophthalmology.The animal models are the key transformation from basic research to clinical outcome.Visual function testing in laboratory animals is also a very important indicator in animal study.For example,psychophysical methods are the main means to check human vision function,but not suitable for animals.Therefore,it needs to focus on research of visual function in animals and application of visual function testing in laboratory animals.

  8. PTGIBBS—an EXCEL TM Visual Basic program for computing and visualizing thermodynamic functions and equilibria of rock-forming minerals

    Science.gov (United States)

    Brandelik, A.; Massonne, H.-J.

    2004-11-01

    PTGIBBS, a Visual Basic for Application program, was implemented in EXCEL TM. It calculates mineral equilibria and thermodynamic functions for diverse solid solution phases, including presentation in 2D- and 3D-plots. The program is also suitable for the calibration and subsequent application of geothermobarometers, because of its ability to simultaneously calculate a large number of equilibria of the same type. Options are provided for the application of various equations of state (EOS). The volume behavior of mineral phases as a function of pressure can be expressed, e.g. by the Murnaghan EOS. It is also possible to model order-disorder transitions and lambda heat capacity anomalies using a tricritical Landau model including pressure dependence. Thus, PTGIBBS can be used with different thermodynamic data sets. It can handle molecular mixing models and mixing-on-site models with a maximum of nine components for each solid solution phase. An event-driven, interactive operating mode was selected for easy application of the program. Another advantage is the implementation in EXCEL TM, resulting in a wide range of possible applications and the user-friendliness of PTGIBBS. The easy display of different thermodynamic functions and the simplicity with which input data sets can be changed may also be useful for teaching purposes.

  9. VERP and brain imaging for identifying levels of visual dorsal and ventral stream function in typical and preterm infants.

    Science.gov (United States)

    Braddick, Oliver; Atkinson, Janette; Wattam-Bell, John

    2011-01-01

    Visual development is a key area for understanding and assessing early brain development. Different levels in the hierarchy of visual processing, from the initial response to flashes of light, through selective responses to contour orientation and motion in primary visual cortex (V1), to global processing in extrastriate of large-scale patterns of form and motion, can each be assessed using stimuli designed to isolate specific neural activity in visual event-related potentials (VERPs). This approach has been used to reveal the sequence of emergence of different visual cortical functions in the first 6 months of typical human development, and to provide early indicators of anomalies in brain development. Delayed or absent onset of orientation-reversal (OR-)VERPs, as a measure of cortical development, has been shown to be a sensitive indicator of perinatal brain damage in both term-born and prematurely born infants. Direction-reversal (DR-)VERPs appear a few weeks later than OR-VERPs in typical development, and are further delayed in even healthy children born preterm, reflecting possible early vulnerability of the motion (dorsal stream) system. High-density recordings of responses to global motion and global form patterns show that these extrastriate systems are typically functional by 5 months of age, but the topography of the activity distributions shows that the brain systems underlying these responses are radically reorganized between infancy and adulthood. In prematurely born infants whose structural brain MRI was evaluated at birth, the onset of the response is absent or delayed in those with severe brain injury, while in those with mild/moderate brain injury the response is present but its spatial organization is further from the adult pattern than those in controls. These findings are related to the development of distinct networks of brain areas in the dorsal and ventral cortical streams, and the apparent vulnerability of the dorsal-stream network in a wide

  10. Functional relationships between the hippocampus and dorsomedial striatum in learning a visual scene-based memory task in rats.

    Science.gov (United States)

    Delcasso, Sébastien; Huh, Namjung; Byeon, Jung Seop; Lee, Jihyun; Jung, Min Whan; Lee, Inah

    2014-11-19

    The hippocampus is important for contextual behavior, and the striatum plays key roles in decision making. When studying the functional relationships with the hippocampus, prior studies have focused mostly on the dorsolateral striatum (DLS), emphasizing the antagonistic relationships between the hippocampus and DLS in spatial versus response learning. By contrast, the functional relationships between the dorsomedial striatum (DMS) and hippocampus are relatively unknown. The current study reports that lesions to both the hippocampus and DMS profoundly impaired performance of rats in a visual scene-based memory task in which the animals were required to make a choice response by using visual scenes displayed in the background. Analysis of simultaneous recordings of local field potentials revealed that the gamma oscillatory power was higher in the DMS, but not in CA1, when the rat performed the task using familiar scenes than novel ones. In addition, the CA1-DMS networks increased coherence at γ, but not at θ, rhythm as the rat mastered the task. At the single-unit level, the neuronal populations in CA1 and DMS showed differential firing patterns when responses were made using familiar visual scenes than novel ones. Such learning-dependent firing patterns were observed earlier in the DMS than in CA1 before the rat made choice responses. The present findings suggest that both the hippocampus and DMS process memory representations for visual scenes in parallel with different time courses and that flexible choice action using background visual scenes requires coordinated operations of the hippocampus and DMS at γ frequencies. Copyright © 2014 the authors 0270-6474/14/3415534-14$15.00/0.

  11. Receptive Field Vectors of Genetically-Identified Retinal Ganglion Cells Reveal Cell-Type-Dependent Visual Functions.

    Directory of Open Access Journals (Sweden)

    Matthew L Katz

    Full Text Available Sensory stimuli are encoded by diverse kinds of neurons but the identities of the recorded neurons that are studied are often unknown. We explored in detail the firing patterns of eight previously defined genetically-identified retinal ganglion cell (RGC types from a single transgenic mouse line. We first introduce a new technique of deriving receptive field vectors (RFVs which utilises a modified form of mutual information ("Quadratic Mutual Information". We analysed the firing patterns of RGCs during presentation of short duration (~10 second complex visual scenes (natural movies. We probed the high dimensional space formed by the visual input for a much smaller dimensional subspace of RFVs that give the most information about the response of each cell. The new technique is very efficient and fast and the derivation of novel types of RFVs formed by the natural scene visual input was possible even with limited numbers of spikes per cell. This approach enabled us to estimate the 'visual memory' of each cell type and the corresponding receptive field area by calculating Mutual Information as a function of the number of frames and radius. Finally, we made predictions of biologically relevant functions based on the RFVs of each cell type. RGC class analysis was complemented with results for the cells' response to simple visual input in the form of black and white spot stimulation, and their classification on several key physiological metrics. Thus RFVs lead to predictions of biological roles based on limited data and facilitate analysis of sensory-evoked spiking data from defined cell types.

  12. Postoperative changes in visual evoked potentials and cognitive function tests following sevoflurane anaesthesia.

    LENUS (Irish Health Repository)

    Iohom, G

    2012-02-03

    We tested the hypothesis that minor disturbance of the visual pathway persists following general anaesthesia even when clinical discharge criteria are met. To test this, we measured visual evoked potentials (VEPs) in 13 ASA I or II patients who did not receive any pre-anaesthetic medication and underwent sevoflurane anaesthesia. VEPs were recorded on four occasions, before anaesthesia and at 30, 60, and 90 min after emergence from anaesthesia. Patients completed visual analogue scales (VAS) for sedation and anxiety, a Trieger Dot Test (TDT) and a Digit Symbol Substitution Test (DSST) immediately before each VEP recording. These results were compared using Student\\'s t-test. P<0.05 was considered significant. VEP latency was prolonged (P<0.001) and amplitude diminished (P<0.05) at 30, 60, and 90 min after emergence from anaesthesia, when VAS scores for sedation and anxiety, TDT, and DSST had returned to pre-anaesthetic levels.

  13. The artist emerges: visual art learning alters neural structure and function.

    Science.gov (United States)

    Schlegel, Alexander; Alexander, Prescott; Fogelson, Sergey V; Li, Xueting; Lu, Zhengang; Kohler, Peter J; Riley, Enrico; Tse, Peter U; Meng, Ming

    2015-01-15

    How does the brain mediate visual artistic creativity? Here we studied behavioral and neural changes in drawing and painting students compared to students who did not study art. We investigated three aspects of cognition vital to many visual artists: creative cognition, perception, and perception-to-action. We found that the art students became more creative via the reorganization of prefrontal white matter but did not find any significant changes in perceptual ability or related neural activity in the art students relative to the control group. Moreover, the art students improved in their ability to sketch human figures from observation, and multivariate patterns of cortical and cerebellar activity evoked by this drawing task became increasingly separable between art and non-art students. Our findings suggest that the emergence of visual artistic skills is supported by plasticity in neural pathways that enable creative cognition and mediate perceptuomotor integration. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Development and Evaluation of Secure Socket Layer Visualization Tool with Packet Capturing Function

    Directory of Open Access Journals (Sweden)

    Arai Masayuki

    2015-01-01

    Full Text Available Secure Socket Layer (SSL has become a fundamental technology that secures browser-processed personal details sent to the server. As a result, communication and computer engineers are advised to learn the protocol. However, understanding SSL is very difficult because of its intricate communication procedure. To solve this problem, we developed a visualization tool for understanding SSL. This paper describes the design, implementation methods, and evaluation of the tool. The evaluation results show that the visualization tool is effective for learning SSL.

  15. 视力及视野损害与交通事故%Visual function damage and driving accidents

    Institute of Scientific and Technical Information of China (English)

    胡爱莲; 杨晓慧; 孙葆忱; 郑远远

    2014-01-01

    视力和视野是安全驾驶的必要条件.各国获取驾驶执照对视力和视野要求不同,但大多数国家视力标准为双眼视力不能低于0.5,水平视野为120°.在过去20年里,大量的研究关注视觉在驾驶中所起的作用,视觉损害对发生交通事故的影响.较早期的研究证明,视觉损害可使事故增加,视觉与事故有明显的相关性.但近期大量的研究认为较好视觉与较差视觉相比事故发生率无差别,因而认为视觉与交通事故无明显相关.上述两种研究结果互相矛盾,可能是由于安全驾驶是需要人、车及环境因素成功地整合及参与才能完成.因此,建议今后关于安全驾驶的研究除视觉外,尚需考虑其他因素.%Visual acuity and visual field is a necessary condition for safe driving.The current licensing authority's visual acuity and visual field standards are different in different country.The current licensing authority's visual acuity and visual field standards are met when a person demonstrates visual acuity better than 0.5 and an intact visual field extending horizontally at least 120 degrees in many countries.In the past two decades,a lot of researches have focused on the effects of vision on driving,the link between impaired vision and driving accident.These results concur with previous literature that driving accidents for drivers with impaired vision more than those with good vision and there was obvious significant correlation between visual acuity and the accidents.Recent studies have shown that there're no difference in driving accidents between drivers with impaired vision and those with good vision.Therefore someone believes the driving accident was no significant correlation with visual function.These two contradictory findings may be due to safe driving is integration of a variety of factors such as people,vehicles and environmental factors.Future research for safe driving should involve not only the visual function

  16. Neural Responses to Visual Food Cues According to Weight Status: A Systematic Review of Functional Magnetic Resonance Imaging Studies

    Directory of Open Access Journals (Sweden)

    Kirrilly ePursey

    2014-07-01

    Full Text Available Emerging evidence from recent neuroimaging studies suggests specific food related behaviours contribute to the development of obesity. The aim of this review was to report the neural responses to visual food cues, as assessed by functional magnetic resonance imaging (fMRI, in humans of differing weight status. Published studies to 2014 were retrieved and included if they: used visual food cues, studied humans >18 years old, reported weight status, and included fMRI outcomes. Sixty studies were identified that investigated the neural responses of healthy weight participants (n=26, healthy weight compared to obese participants (n=17, and weight loss interventions (n=12. High calorie food images were used in the majority of studies (n=36, however, image selection justification was only provided in 19 studies. Obese individuals had increased activation of reward-related brain areas including the insula and orbitofrontal cortex in response to visual food cues compared to healthy weight individuals, and this was particularly evident in response to energy dense cues. Additionally, obese individuals were more responsive to food images when satiated. Meta-analysis of changes in neural activation post- weight loss revealed small areas of convergence of activation across studies in brain areas related to emotion, memory and learning such as the cingulate gyrus, lentiform nucleus and precuneus.Differential activation patterns to visual food cues were observed between obese, healthy weight and weight loss populations. Future studies require standardisation of dietetic variables and fMRI outcomes to enable more direct comparisons between studies.

  17. Retinal atrophy in relation to visual functioning and vision-related quality of life in patients with multiple sclerosis.

    Science.gov (United States)

    Balk, Lisanne J; Coric, Danko; Nij Bijvank, Jenny A; Killestein, Joep; Uitdehaag, Bernard Mj; Petzold, Axel

    2017-05-01

    Inner retinal layer atrophy in patients with multiple sclerosis (MS) has been validated as a structural imaging biomarker for neurodegeneration. To determine how retinal layer thickness relates to high-contrast visual acuity (HCVA), low-contrast visual acuity (LCVA) and vision-related quality of life (QoL) and to investigate the effect of previous episodes on MS-associated optic neuritis (MSON). Spectral-domain optical coherence tomography (SD-OCT) was performed in 267 patients with MS. Images were segmented for the peripapillary retinal nerve fiber layer (pRNFL) and the macular ganglion cell inner plexiform layer (GCIPL). Ophthalmological evaluations included history of MSON, HCVA, LCVA, and vision-related QoL. Independent of MSON, HCVA and LCVA were significantly associated with pRNFL and GCIPL thicknesses. Vision-related QoL was positively associated with pRNFL (β = 0.92, p = 0.06) and GCIPL (β = 0.93, p = 0.02) thicknesses. These associations were independent of MSON. Not only binocular but also monocular atrophy of the inner retinal layers was associated with lower vision-related QoL. This study showed that retinal atrophy has a significant impact on visual functioning in patients with MS. OCT may therefore provide useful insight to patients with visual dysfunction, and our findings support including OCT and vision-related QoL measures into optic neuritis treatment trials.

  18. Effects of oculo-motor exercise, functional electrical stimulation and proprioceptive neuromuscular stimulation on visual perception of spatial neglect patients.

    Science.gov (United States)

    Park, Si-Eun; Oh, Dae-Sik; Moon, Sang-Hyun

    2016-04-01

    [Purpose] The purpose of this study was to identify the effects of oculo-motor exercise, functional electrical stimulation (FES), and proprioceptive neuromuscular facilitation (PNF) on the visual perception of spatial neglect patients. [Subjects and Methods] The subjects were randomly allocated to 3 groups: an oculo-motor exercise (OME) group, a FES with oculo-motor exercise (FOME) group, and a PNF with oculo-motor exercise (POME) group. The line bisection test (LBT), motor free visual test (MVPT), and Catherine Bergego Scale (CBS) were used to measure visual perception. These were performed 5 times per week for 6 weeks. [Results] The OME group and POME group showed significant improvements according to the LBT and MVPT results, but the FOME group showed no significant improvement. According to the CBS, all 3 groups showed significant improvements. The OME and POME groups showed improvement over the FOME group in the LBT and MVPT. However, there was no significant difference among the three groups according to the CBS. [Conclusion] These results indicate that oculo-motor exercise and PNF with oculo-motor exercise had more positive effects than FES with oculo-motor exercise on the visual perception of spatial neglect patients.

  19. VISUALIZATION IN THE PACKAGE AUTODESK INVENTOR SKETCH GEOMETRY WHEN USING TOOLS IN THE THEORY OF R-FUNCTIONS

    Directory of Open Access Journals (Sweden)

    E. Іvanov

    2015-12-01

    Full Text Available The paper deals with possibility of automation and control of the computational process when using the tools in the theory of R-functions possessing the properties of logic algebra, while not going beyond the elementary functions, make it possible to build the equations of geometric objects with an almost arbitrary shape. And the use of computer graphics makes it posible to represent the equation of the boundar surface and the conical region of the curved tooth coupling and the whole disk in on analytical form with possible visualization in the Autodesk Inventor package.

  20. Comparative study on direction selectivity and functional organization of the primary visual cortical cells in monkeys and cats

    Institute of Scientific and Technical Information of China (English)

    寿天德; 周逸峰; 俞洪波

    2000-01-01

    Although the directionally selective cells in many visual cortical areas are organized in columnar manner, the functional organization of direction selectivity of area VI in the monkey still remains unclear. We quantitatively studied the proportion of directionally selective cells, direction selectivity and the functional organization of the striate cortical cells in the monkey and compared those with the cat. The results show that the direction selectivity and directional organization of striate cortical cells in the monkey are significantly weaker than those in the cat, suggesting that the species difference between the two kinds of animal is related to their different anatomic pathways.

  1. Comparative study on direction selectivity and functional organization of the primary visual cortical cells in monkeys and cats

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Although the directionally selective cells in many visual cortical areas are organized in columnar manner, the functional organization of direction selectivity of area Vl in the monkey still remains unclear. We quantitatively studied the proportion of directionally selective cells, direction selectivity and the functional organization of the striate cortical cells in the monkey and compared those with the cat. The results show that the direction selectivity and directional organization of striate cortical cells in the monkey are significantly weaker than those in the cat, suggesting that the species difference between the two kinds of animal is related to their different anatomic pathways.

  2. Visual Attention as a Function of Sex and Apparel of Stimulus Object: Who Looks at Whom?

    Science.gov (United States)

    Rosenwasser, Shirley Miller; And Others

    1983-01-01

    Examined same-sex awareness by comparing the visual attention of 51 college students toward stimulus persons. Results showed men looked longer at slides of women both clothed and in bathing suits than slides of men, and women looked longest at slides of clothed women. Results suggested intrasex competitiveness and intersex attraction. (JAC)

  3. Higher Brain Functions Served by the Lowly Rodent Primary Visual Cortex

    Science.gov (United States)

    Gavornik, Jeffrey P.; Bear, Mark F.

    2014-01-01

    It has been more than 50 years since the first description of ocular dominance plasticity--the profound modification of primary visual cortex (V1) following temporary monocular deprivation. This discovery immediately attracted the intense interest of neurobiologists focused on the general question of how experience and deprivation modify the brain…

  4. Higher Brain Functions Served by the Lowly Rodent Primary Visual Cortex

    Science.gov (United States)

    Gavornik, Jeffrey P.; Bear, Mark F.

    2014-01-01

    It has been more than 50 years since the first description of ocular dominance plasticity--the profound modification of primary visual cortex (V1) following temporary monocular deprivation. This discovery immediately attracted the intense interest of neurobiologists focused on the general question of how experience and deprivation modify the brain…

  5. Red fluorescence increases with depth in reef fishes, supporting a visual function, not UV protection.

    Science.gov (United States)

    Meadows, Melissa G; Anthes, Nils; Dangelmayer, Sandra; Alwany, Magdy A; Gerlach, Tobias; Schulte, Gregor; Sprenger, Dennis; Theobald, Jennifer; Michiels, Nico K

    2014-09-07

    Why do some marine fishes exhibit striking patterns of natural red fluorescence? In this study, we contrast two non-exclusive hypotheses: (i) that UV absorption by fluorescent pigments offers significant photoprotection in shallow water, where UV irradiance is strongest; and (ii) that red fluorescence enhances visual contrast at depths below -10 m, where most light in the 'red' 600-700 nm range has been absorbed. Whereas the photoprotection hypothesis predicts fluorescence to be stronger near the surface and weaker in deeper water, the visual contrast hypothesis predicts the opposite. We used fluorometry to measure red fluorescence brightness in vivo in individuals belonging to eight common small reef fish species with conspicuously red fluorescent eyes. Fluorescence was significantly brighter in specimens from the -20 m sites than in those from -5 m sites in six out of eight species. No difference was found in the remaining two. Our results support the visual contrast hypothesis. We discuss the possible roles fluorescence may play in fish visual ecology and highlight the possibility that fluorescent light emission from the eyes in particular may be used to detect cryptic prey.

  6. Real-time kymographic imaging for visualizing human vocal-fold vibratory function

    NARCIS (Netherlands)

    Qiu, Qingjun; Schutte, Harm K.

    2007-01-01

    A stand-alone kymographic system for visualizing human vocal-fold vibration in real time is presented. By using a dual charge-coupled-device construction, the system not only provides kymographic images but also simultaneously presents structural images for navigating the endoscope to a desired posi

  7. PanViz: interactive visualization of the structure of functionally annotated pangenomes

    DEFF Research Database (Denmark)

    Pedersen, Thomas Lin; Nookaew, Intawat; Wayne Ussery, David

    2017-01-01

    Script and is available on https://github.com/thomasp85/PanViz A companion R package that facilitates the creation of PanViz visualizations from a range of data formats is released through Bioconductor and is available at https://bioconductor.org/packages/PanVizGenerator CONTACT: thomasp85@gmail...

  8. What is your neural function, visual narrative conjunction? Grammar, meaning, and fluency in sequential image processing.

    Science.gov (United States)

    Cohn, Neil; Kutas, Marta

    2017-01-01

    Visual narratives sometimes depict successive images with different characters in the same physical space; corpus analysis has revealed that this occurs more often in Japanese manga than American comics. We used event-related brain potentials to determine whether comprehension of "visual narrative conjunctions" invokes not only incremental mental updating as traditionally assumed, but also, as we propose, "grammatical" combinatoric processing. We thus crossed (non)/conjunction sequences with character (in)/congruity. Conjunctions elicited a larger anterior negativity (300-500 ms) than nonconjunctions, regardless of congruity, implicating "grammatical" processes. Conjunction and incongruity both elicited larger P600s (500-700 ms), indexing updating. Both conjunction effects were modulated by participants' frequency of reading manga while growing up. Greater anterior negativity in frequent manga readers suggests more reliance on combinatoric processing; larger P600 effects in infrequent manga readers suggest more resources devoted to mental updating. As in language comprehension, it seems that processing conjunctions in visual narratives is not just mental updating but also partly grammatical, conditioned by comic readers' experience with specific visual narrative structures.

  9. Diversification of non-visual photopigment parapinopsin in spectral sensitivity for diverse pineal functions.

    Science.gov (United States)

    Koyanagi, Mitsumasa; Wada, Seiji; Kawano-Yamashita, Emi; Hara, Yuichiro; Kuraku, Shigehiro; Kosaka, Shigeaki; Kawakami, Koichi; Tamotsu, Satoshi; Tsukamoto, Hisao; Shichida, Yoshinori; Terakita, Akihisa

    2015-09-15

    Recent genome projects of various animals have uncovered an unexpectedly large number of opsin genes, which encode protein moieties of photoreceptor molecules, in most animals. In visual systems, the biological meanings of this diversification are clear; multiple types of visual opsins with different spectral sensitivities are responsible for color vision. However, the significance of the diversification of non-visual opsins remains uncertain, in spite of the importance of understanding the molecular mechanism and evolution of varied non-visual photoreceptions. Here, we investigated the diversification of the pineal photopigment parapinopsin, which serves as the UV-sensitive photopigment for the pineal wavelength discrimination in the lamprey, linking it with other pineal photoreception. Spectroscopic analyses of the recombinant pigments of the two teleost parapinopsins PP1 and PP2 revealed that PP1 is a UV-sensitive pigment, similar to lamprey parapinopsin, but PP2 is a blue-sensitive pigment, with an absorption maximum at 460-480 nm, showing the diversification of non-visual pigment with respect to spectral sensitivity. We also found that PP1 and PP2 exhibit mutually exclusive expressions in the pineal organs of three teleost species. By using transgenic zebrafish in which these parapinopsin-expressing cells are labeled, we found that PP1-expressing cells basically possess neuronal processes, which is consistent with their involvement in wavelength discrimination. Interestingly, however, PP2-expressing cells rarely possess neuronal processes, raising the possibility that PP2 could be involved in non-neural responses rather than neural responses. Furthermore, we found that PP2-expressing cells contain serotonin and aanat2, the key enzyme involved in melatonin synthesis from serotonin, whereas PP1-expressing cells do not contain either, suggesting that blue-sensitive PP2 is instead involved in light-regulation of melatonin secretion. In this paper, we have clearly

  10. Electrophysiological testing of visual function after mirror telescope implantation: a case report.

    Science.gov (United States)

    Kremláček, Jan; Jirásková, Naďa; Nekolová, Jana; Šikl, Radovan; Kuba, Miroslav

    2016-12-01

    The implantation of an intraocular telescope increases life quality in patients with end-stage age-related macular degeneration (AMD). The present study monitored changes in electrophysiological markers of visual processing before and during seventeen months after a novel mirror telescope implantation in two patients (OV-male 90 years, MZ-female 70 years) with the final-stage form of AMD. Visual evoked potentials were recorded to high-contrast pattern-reversal (PR-VEP for check size 40' and 10'), low-contrast motion-onset stimuli (in visual periphery M-VEP M20°, and in central part M-VEP C8°), and event-related potentials (ERPs) in the oddball visual paradigm. MZ's more systematic responses showed attenuation and prolongation of the M-VEP M20° and the PR-VEP 40' immediately after the telescope implantation with a slow amplitude recovery with unchanged prolonged latency. The implantation completely eradicated the M-VEP C8° without any restoration. The PR-VEP 10' were not readable. Only a part of OV's PR-VEP 40' and M-VEP M20' were of a repeatable and expected morphology. These OV's VEPs were consistent with MZ's findings. The ERPs did not show any effect of implantation in both patients. Post-implantation visual acuity and reaction time overcame the pre-implantation levels. The mirror telescope preserved peripheral vision in contrast to classic telescopes; however, the telescope concurrently reduced the luminance of the magnified retinal image, which was likely responsible for the prolongation of the VEP latencies.

  11. Wave-function Visualization of Core-induced Interaction of Non-hydrogenic Rydberg Atom in Electric Field

    CERN Document Server

    Gao, W; Cheng, H; Zhang, S S; Liu, H P

    2015-01-01

    We have investigated the wave-function feature of Rydberg sodium in a uniform electric field and found that the core-induced interaction of non-hydrogenic atom in electric field can be directly visualized in the wave-function. As is well known, the hydrogen atom in electric field can be separated in parabolic coordinates (\\eta, \\xi), whose eigen-function can show a clear pattern towards negative and positive directions corresponding to the so-called red and blue states without ambiguity, respectively. It can be served as a complete orthogonal basis set to study the core-induced interaction of non-hydrogenic atom in electric field. Owing to complete different patterns of the probability distribution for red and blue states, the interaction can be visualized in the wave-function directly via superposition. Moreover, the constructive and destructive interferences between red and blue states are also observed in the wave-function, explicitly explaining the experimental measurement for the spectral oscillator stre...

  12. Comparative study of visual functions in premature pre-school children with and without retinopathy of prematurity

    Directory of Open Access Journals (Sweden)

    Lígia Beatriz Bonotto

    2014-01-01

    Full Text Available Purpose: Observe whether there are differences in visual functions among premature infants with treated retinopathy of prematurity (ROP in relation to preterm infants with ROP and spontaneous regression; and among these two groups with ROP and the control group without ROP. Methods: Crosssectional observational no blind study. Premature infants were born between 06/199206/2006 and were exam between 06/200912/2010; registered in data of Hospital de Olhos Sandalla Amin Ghanem; with gestational age less than or equal to 32 weeks and 1,599 g born weigh; without ROP and ROP stages II or III, in one of the eyes, with spontaneous regression or with treatment; at least three visits during the selection period at maximum 6 months in the first exam and minimum 4 years of age in reassessment (chronological age were include. Premature that did not respond or were not located for reassessment and those that did not have conditions to do the exams were exclude. Study's groups: G1 ROP posttreatment; G2ROP postspontaneous regression; G3 without ROP (control. Visual function evaluated with visual acuity (VA, contrast sensitivity test (CST, color test (CT, eye movement, stereopsis. Results: Overall, there were 24 premature infants and 48 eyes. Normal VA: 64.28% (G1, 87.5% (G2 and 100% (G3; Normal CST: 66.67% (G1, 100% (G2 and 55.56% (G3; Normal Ishihara CT: 100% (G1 and G2 and 86% (G3; Normal Farnsworth CT: 20% (G1, 75% (G2 and 50% (G3. Normal stereoacuity: 0.00% (G1; 25% (G2 and 3.5% (G3. Strabismus: 37% (G2, 0.00% (G1 and G3. The prevalent tendency for lower response in CST and CT between the premature children in group G3 and Farnsworth color test in G1 is a curious result of this work and more study is necessary about these visual functions in older premature children. Conclusion: The visual functions showed no statistically significant difference among the groups studied.

  13. Treatment with citicoline eye drops enhances retinal function and neural conduction along the visual pathways in open angle glaucoma.

    Science.gov (United States)

    Parisi, Vincenzo; Centofanti, Marco; Ziccardi, Lucia; Tanga, Lucia; Michelessi, Manuele; Roberti, Gloria; Manni, Gianluca

    2015-08-01

    To evaluate the retinal function and the neural conduction along the visual pathways after treatment with citicoline eye drops in patients with open angle glaucoma (OAG). Fifty-six OAG patients (mean age 52.4 ± 4.72 years, IOP  0.01) PERG and VEP values in GC and GP eyes were observed. After treatment with topical citicoline, a significant (p  0.01) to baseline ones. GP eyes showed not significant changes of PERG and VEP values during the entire follow-up. Topical treatment with citicoline in OAG eyes induces an enhancement of the retinal bioelectrical responses (increase of PERG amplitude) with a consequent improvement of the bioelectrical activity of the visual cortex (shortening and increase of VEP implicit time and amplitude, respectively).

  14. JDet: interactive calculation and visualization of function-related conservation patterns in multiple sequence alignments and structures.

    Science.gov (United States)

    Muth, Thilo; García-Martín, Juan A; Rausell, Antonio; Juan, David; Valencia, Alfonso; Pazos, Florencio

    2012-02-15

    We have implemented in a single package all the features required for extracting, visualizing and manipulating fully conserved positions as well as those with a family-dependent conservation pattern in multiple sequence alignments. The program allows, among other things, to run different methods for extracting these positions, combine the results and visualize them in protein 3D structures and sequence spaces. JDet is a multiplatform application written in Java. It is freely available, including the source code, at http://csbg.cnb.csic.es/JDet. The package includes two of our recently developed programs for detecting functional positions in protein alignments (Xdet and S3Det), and support for other methods can be added as plug-ins. A help file and a guided tutorial for JDet are also available.

  15. 复变函数的可视化问题研究%Research on Visualization of Complex Function

    Institute of Scientific and Technical Information of China (English)

    韩英; 陈佳旗

    2012-01-01

    Complex variable's elementary function (CVEF) has many unique characteristics. However, due to its 4-dimensional nature in graphing, most prior discussions on CVEF has been limited to written analyses. This paper resolved CVEF's visualization issue by using Matlab software to create graphs for CVEF to visually explain its unique characteristics.%复变函数有着许多自己的特性,但由于其图形需用四维表示,现有文献一般都是从理论上分析,未给出图像说明.笔者利用MATLAB软件画出了复变量函数的图形,并借助图形直观说明其特有的性质,解决了复变函数的可视化问题.

  16. Visual and Artistic Functions of Letters in Khaghani’s Poetry

    Directory of Open Access Journals (Sweden)

    Mohsen Zolfaghari

    2013-11-01

    with a new essence. There is a world in the heart of every letter, word and morpheme lies in the poet's point of view is not the last and smallest part of speech, but it is a starting point for the imagination of the poet, to the extent that his sharp and sensitive eye sees a world in every letter. Accordingly, this study includes some of the functions and artistic aspects of letters created novelty and authentic style in Khaghani's poetry.   Auditory and visual aspect (letters of a specific word or appearance of a letter and its resemblance to other things such as the shape of " teeth" and "mouth", shape of letter "s" or " a" and "spear" and "arrow", the semantic aspect of the letters, numerical aspect of letters, inspiring from the separated letters of Quran, the aesthetic aspect of letters (respecting figures of speech, syllable, allegory, ambiguity, metaphor, simile etc.   In general it can be said that the letters have a lot of potential capacity in poetry and Khaghani as a creative poet and modernist is aware of the power of words well and could use skillfully this power in the artistic context of his poetry.

  17. Top-Down and Bottom-Up Visual Information Processing of Non-Social Stimuli in High-Functioning Autism Spectrum Disorder

    Science.gov (United States)

    Maekawa, Toshihiko; Tobimatsu, Shozo; Inada, Naoko; Oribe, Naoya; Onitsuka, Toshiaki; Kanba, Shigenobu; Kamio, Yoko

    2011-01-01

    Individuals with high-functioning autism spectrum disorder (HF-ASD) often show superior performance in simple visual tasks, despite difficulties in the perception of socially important information such as facial expression. The neural basis of visual perception abnormalities associated with HF-ASD is currently unclear. We sought to elucidate the…

  18. Visuospatial function in early Alzheimer's disease--the use of the Visual Object and Space Perception (VOSP battery.

    Directory of Open Access Journals (Sweden)

    Natália Bezerra Mota Quental

    Full Text Available Alzheimer's disease (AD is the most frequent cause of dementia. The clinical symptoms of AD begin with impairment of memory and executive function followed by the gradual involvement of other functions, such as language, semantic knowledge, abstract thinking, attention, and visuospatial abilities. Visuospatial function involves the identification of a stimulus and its location and can be impaired at the beginning of AD. The Visual Object and Space Perception (VOSP battery evaluates visuospatial function, while minimizing the interference of other cognitive functions.To evaluate visuospatial function in early AD patients using the VOSP and determine cutoff scores to differentiate between cognitively healthy individuals and AD patients.Thirty-one patients with mild AD and forty-four healthy elderly were evaluated using a neuropsychological battery and the VOSP.In the VOSP, the AD patients performed more poorly in all subtests examining object perception and in two subtests examining space perception (Number Location and Cube Analysis. The VOSP showed good accuracy and good correlation with tests measuring visuospatial function.Visuospatial function is impaired in the early stages of AD. The VOSP battery is a sensitive battery test for visuospatial deficits with minimal interference by other cognitive functions.

  19. The effect of tinted soft contact lens wear on functional visual acuity and higher-order aberrations.

    Science.gov (United States)

    Watanabe, Kazuhiro; Kaido, Minako; Ishida, Reiko; Dogru, Murat; Negishi, Kazuno; Tsubota, Kazuo

    2014-06-01

    To investigate the differences of functional visual acuity (FVA) and high order aberrations (HOAs) in relation to tinted and clear hydrogel soft contact lens (SCL) wear. A prospective comparative study was performed in 16 eyes of 16 healthy volunteers. Dynamic visual acuity (using a FVA measurement system) and higher-order aberrations (using a wavefront sensor) were compared in subjects wearing two types of soft contact lenses: 1-day Acuvue(®) (Vistakon, Jacksonville, FL) clear and the 1-day Acuvue(®) Define(TM) (Vistakon, Jacksonville, FL) tinted lens. The blink rates were recorded during FVA testing. The correlation between the difference of HOAs and differences in FVA values was analyzed. The mean LogMAR FVA scores with clear and tinted SCLs were 0.07 ± 0.13 and 0.14 ± 0.17 (P<0.05). The mean blink frequencies with clear and tinted SCL wear were 18.4 ± 8.3 and 25.3 ± 4.7 blinks/min (P<0.05). Both 3rd-order aberrations and total HOAs showed statistically significant differences between the two types of soft contact lenses for 6mm pupil measurements (P<0.05). A significant positive linear correlation was observed between ΔHOAs and ΔLogMAR FVA for 6mm pupil measurements (R=0.53, P=0.04). Tinted contact lens wear appears to induce a reduction in optical quality. Functional visual acuity measurement is a useful procedure to study the changes of visual performance and quality in tinted contact lens wear. Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  20. Effects of deuterium oxide and galvanic vestibular stimulation on visual cortical cell function

    Energy Technology Data Exchange (ETDEWEB)

    Reinis, S.; Landolt, J.P.; Weiss, D.S.; Money, K.E.

    1984-03-01

    The spontaneous and evoked unit activities of complex visual cortical cells were recorded from Brodmann's area 18 in immobilized, unanesthetized cats before, during, and after stimulation of the vestibular system. The vestibular system was stimulated by intravenous injection of deuterium oxide (D2O)--a noted nystagmogenic agent--or by direct galvanic stimulation of the labyrinth. Measures of the receptive-field areas, poststimulus time histograms, directional preferences, and the optimal speed of the light bar stimulating the cell were obtained before and after the application of D2O. Directional preferences were determined in a novel manner, using a method derived from a hierarchical clustering technique. Data were collected and analyzed from a) visual cortical cells in cats with intact labyrinths, b) visual cortical cells in cats following bilateral labrinthectomies, and c) nonvisual cortical cells in cats with intact labyrinths. The other cellular characteristics were also altered by the D2O. Galvanic stimulation of the labyrinth resembles, in its effects, the injection of D2O. In labyrinth-intact cats, the time course of area 18 spontaneous activity dramatically increased 30 min or more after D2O was administered. It peaked 2-3 h later and still had not returned to preinjection levels even 7 h after the D2O administration. In bilaterally labyrinthectomized cats, the spontaneous activity of the visual cells did not change following D2O administration. In nonvisual cells from labyrinth-intact cats, the spontaneous activity demonstrated a slight but significant decrease over time after D2O injection. In pilot studies, the cats were injected with D2O. Within 8-10 min afterward, signs of positional nystagmus commenced; and within 30 min, problems in maintaining balance were noted. This continued for 7-8 h before disappearing. In the labyrinthectomized animals, such effects were not observed.

  1. [Evaluation of visual-motor integration functions in children between 6-15 years of age].

    Science.gov (United States)

    Tekok Kiliç, Ayda; Elmastas-Dikec, Banu; Can, Handan

    2010-01-01

    Visual-motor integration skills are considered an essential domain of clinical and psycho-educational assessment. The goal of the present investigation is to provide the Turkish norms for the Beery-Buktenica Developmental Visual-Motor Integration Test (VMI-4th) for children and adolescents between the ages of 6-15 years as part of a comprehensive neuropsychological test battery. A total of 1887 children from elementary and high schools in the city of Bursa were recruited for this study. From this sample 44 children were re-tested 3-4 weeks following the first administration for test-retest reliability. Findings showed clear developmental trajectories in visual-motor integration skills. Significant performance increments were observed in six month intervals for ages 6 and 7. Starting from age 8, norms were established for each age group separately. Girls and boys performed similarly on the VMI-4. Test- retest correlation was modest but within an acceptable range. The age-based norms established for the VMI-4 in this study can be used to assess children between the ages of 6-15 years as part of a clinical neuropsychological and a psycho-educational assessment. The mean VMI scores presented in this study represent performance of children in middle and middle-upper socio-economic status and may not represent the normal performance range of children from lower SES.

  2. Eyetracking Metrics in Young Onset Alzheimer’s Disease: A Window into Cognitive Visual Functions

    Science.gov (United States)

    Pavisic, Ivanna M.; Firth, Nicholas C.; Parsons, Samuel; Rego, David Martinez; Shakespeare, Timothy J.; Yong, Keir X. X.; Slattery, Catherine F.; Paterson, Ross W.; Foulkes, Alexander J. M.; Macpherson, Kirsty; Carton, Amelia M.; Alexander, Daniel C.; Shawe-Taylor, John; Fox, Nick C.; Schott, Jonathan M.; Crutch, Sebastian J.; Primativo, Silvia

    2017-01-01

    Young onset Alzheimer’s disease (YOAD) is defined as symptom onset before the age of 65 years and is particularly associated with phenotypic heterogeneity. Atypical presentations, such as the clinic-radiological visual syndrome posterior cortical atrophy (PCA), often lead to delays in accurate diagnosis. Eyetracking has been used to demonstrate basic oculomotor impairments in individuals with dementia. In the present study, we aim to explore the relationship between eyetracking metrics and standard tests of visual cognition in individuals with YOAD. Fifty-seven participants were included: 36 individuals with YOAD (n = 26 typical AD; n = 10 PCA) and 21 age-matched healthy controls. Participants completed three eyetracking experiments: fixation, pro-saccade, and smooth pursuit tasks. Summary metrics were used as outcome measures and their predictive value explored looking at correlations with visuoperceptual and visuospatial metrics. Significant correlations between eyetracking metrics and standard visual cognitive estimates are reported. A machine-learning approach using a classification method based on the smooth pursuit raw eyetracking data discriminates with approximately 95% accuracy patients and controls in cross-validation tests. Results suggest that the eyetracking paradigms of a relatively simple and specific nature provide measures not only reflecting basic oculomotor characteristics but also predicting higher order visuospatial and visuoperceptual impairments. Eyetracking measures can represent extremely useful markers during the diagnostic phase and may be exploited as potential outcome measures for clinical trials. PMID:28824534

  3. Eyetracking Metrics in Young Onset Alzheimer’s Disease: A Window into Cognitive Visual Functions

    Directory of Open Access Journals (Sweden)

    Ivanna M. Pavisic

    2017-08-01

    Full Text Available Young onset Alzheimer’s disease (YOAD is defined as symptom onset before the age of 65 years and is particularly associated with phenotypic heterogeneity. Atypical presentations, such as the clinic-radiological visual syndrome posterior cortical atrophy (PCA, often lead to delays in accurate diagnosis. Eyetracking has been used to demonstrate basic oculomotor impairments in individuals with dementia. In the present study, we aim to explore the relationship between eyetracking metrics and standard tests of visual cognition in individuals with YOAD. Fifty-seven participants were included: 36 individuals with YOAD (n = 26 typical AD; n = 10 PCA and 21 age-matched healthy controls. Participants completed three eyetracking experiments: fixation, pro-saccade, and smooth pursuit tasks. Summary metrics were used as outcome measures and their predictive value explored looking at correlations with visuoperceptual and visuospatial metrics. Significant correlations between eyetracking metrics and standard visual cognitive estimates are reported. A machine-learning approach using a classification method based on the smooth pursuit raw eyetracking data discriminates with approximately 95% accuracy patients and controls in cross-validation tests. Results suggest that the eyetracking paradigms of a relatively simple and specific nature provide measures not only reflecting basic oculomotor characteristics but also predicting higher order visuospatial and visuoperceptual impairments. Eyetracking measures can represent extremely useful markers during the diagnostic phase and may be exploited as potential outcome measures for clinical trials.

  4. [The study of functional status in the perception of visual information depending on the method of technical color mixing on LCD and DLP projectors technology].

    Science.gov (United States)

    Merkulova, A G; Osokina, E S; Bukhtiiarov, I V

    2014-10-01

    The case of compare two ways of projection color visual images, characterized by different spatial-temporal characteristics of visual stimuli, presents the methodology and the set of techniques. Received comparative data, identifying risks of regulation disorder of the functional state and development general, mental and visual fatigue during prolonged strenuous visual activity, according to two types of test tasks, which are the most typical for the use of modern projectors to work with the audience, both inthe process of implementation of learning technologies and the collective take responsible decisions by expert groups that control of complex technological processes.

  5. Correlation between single-trial visual evoked potentials and the blood oxygenation level dependent response in simultaneously recorded electroencephalography-functional magnetic resonance imaging

    DEFF Research Database (Denmark)

    Fuglø, Dan; Pedersen, Henrik; Rostrup, Egill

    2012-01-01

    To compare different electroencephalography (EEG)-based regressors and their ability to predict the simultaneously recorded blood oxygenation level dependent response during blocked visual stimulation, simultaneous EEG-functional magnetic resonance imaging in 10 healthy volunteers was performed...

  6. Effects of a novel walking training program with postural correction and visual feedback on walking function in patients with post-stroke hemiparesis

    National Research Council Canada - National Science Library

    Won, Sang Hee; Kim, Jae Cheol; Oh, Duck-Won

    2015-01-01

    [Purpose] This study aimed to elucidate the effects of a novel walking training program with postural correction and visual feedback on walking function in patients with post-stroke hemiparesis. [Subjects...

  7. Exercise and physical training improve physical function in older adults with visual impairments but their effect on falls is unclear: a systematic review

    Directory of Open Access Journals (Sweden)

    Michael Gleeson

    2014-09-01

    [Gleeson M, Sherrington C, Keay L (2014 Exercise and physical training improve physical function in older adults with visual impairments but their effect on falls is unclear: a systematic review. Journal of Physiotherapy 60: 130–135

  8. Severe structural and functional visual system damage leads to profound loss of vision-related quality of life in patients with neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    Schmidt, Felix; Zimmermann, Hanna; Mikolajczak, Janine; Oertel, Frederike C; Pache, Florence; Weinhold, Maria; Schinzel, Johann; Bellmann-Strobl, Judith; Ruprecht, Klemens; Paul, Friedemann; Brandt, Alexander U

    2017-01-01

    Neuromyelitis optica spectrum disorders (NMOSD) are characterized by devastating optic neuritis attacks causing more structural damage and visual impairment than in multiple sclerosis (MS). The objective of this study was to compare vision-related quality of life in NMOSD and MS patients and correlate it to structural retinal damage and visual function. Thirty-one NMOSD and 31 matched MS patients were included. Vision-related quality of life was assessed with the 39-item National Eye Institute Visual Function Questionnaire (NEI-VFQ). All patients underwent retinal optical coherence tomography and visual acuity and contrast sensitivity measurements. Vision-related quality of life was reduced in NMOSD compared to MS patients. This difference was driven by a higher incidence of bilateral and more severe optic neuritis in the NMOSD group. Retinal thinning and visual impairment were significantly greater in the NMOSD cohort. Lower vision-related quality of life was associated with more retinal damage and reduced visual function as assessed by visual acuity and contrast sensitivity. NMOSD-related bilateral ON-attacks cause severe structural damage and visual impairment that lead to severe loss of vision-related quality of life. The NEI-VFQ is a helpful tool to monitor vision-related quality of life in NMOSD patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. How Visual Imagery Contributed to College: A Case of How Visual Imagery Contributes to a College Algebra Student's Understanding of the Concept of Function in the United States

    Science.gov (United States)

    Lane, Rebekah M.

    2011-01-01

    This investigation utilized the qualitative case study method. Seventy-one College Algebra students were given a mathematical processing instrument. This testing device measured a student's preference for visual thinking. Two students were purposefully selected using the instrument. The visual mathematical learner (VL) was discussed in this…

  10. Evaluation of discriminant functions for sexing skulls from visually assessed traits applied in the Rainer Osteological Collection (Bucharest, Romania).

    Science.gov (United States)

    Soficaru, A; Constantinescu, M; Culea, M; Ionică, C

    2014-12-01

    The sexing of human skeletal remains based on visual scoring of descriptive traits on the skull is useful for both forensic and bioarchaeological studies, given that many such features preserve well in the field and can be assessed quickly. The goal of our work is to evaluate the accuracy of this method on an age-balanced, known sex, random sample of 360 modern adult crania in the Rainer Osteological Collection. Consistent with Walker (2008), we scored glabella area (G), the mastoid process (Ma), the mental eminence (M), the orbital edge (O) and the nuchal crest (N), on a five-point scale. We generated sex discriminant functions (logistic), selected the most accurate of them, and subsequently applied them to archaeological samples from Romania. Each skull feature showed significant score differences by sex. Eight out of 31 discriminant functions passed criteria of high accuracy (∼90%), sex bias (±2%), and ease of use (direct calculation of sex). The best estimates were obtained for the 30-60 age groups. Further testing these functions on six archaeological samples showed high percentages of agreement with the sex assessed on the coxal bone. The study also indicated that, although easy to learn by novices, the method of visually scoring the skull traits depends on prior experience with human osteology. The accuracy of the method may be influenced by geographical and historical differences which are bound to exist between populations.

  11. Effects of deuterium oxide and galvanic vestibular stimulation on visual cortical cell function.

    Science.gov (United States)

    Reinis, S; Landolt, J P; Weiss, D S; Money, K E

    1984-03-01

    /he spontaneous and evoked unit activities of complex visual cortical cells were recorded from Brodmann's area 18 in immobilized, unanesthetized cats before, during, and after stimulation of the vestibular system. The vestibular system was stimulated by intravenous injection of deuterium oxide (D2O)--a noted nystagmogenic agent (14)--or by direct galvanic stimulation of the labyrinth. Measures of the receptive-field areas, poststimulus time histograms, directional preferences, and the optimal speed of the light bar stimulating the cell were obtained before and after the application of D2O. Directional preferences were determined in a novel manner, using a method derived from a hierarchical clustering technique (19). Data were collected and analyzed from a) visual cortical cells in cats with intact labyrinths, b) visual cortical cells in cats following bilateral labrinthectomies, and c) nonvisual cortical cells in cats with intact labyrinths. In cats with intact labyrinths, D2O changed the optimal length of the light bar that was able to stimulate the cortical cell as well as the path on which it evoked the response of the cell. Both values, which constitute the receptive field of the cell, changed approximately proportionately. This effect usually lasts for less than 4.5 h. The other cellular characteristics were also altered by the D2O. Galvanic stimulation of the labyrinth resembles, in its effects, the injection of D2O. In labyrinth-intact cats, the time course of area 18 spontaneous activity dramatically increased 30 min or more after D2O was administered. It peaked 2-3 h later and still had not returned to preinjection levels even 7 h after the D2O administration. In bilaterally labyrinthectomized cats, the spontaneous activity of the visual cells (and the other cellular characteristics studied) did not change following D2O administration. In nonvisual cells from labyrinth-intact cats, the spontaneous activity demonstrated a slight but significant decrease

  12. Development of the functional vision questionnaire for children and young people with visual impairment: the FVQ_CYP.

    Science.gov (United States)

    Tadić, Valerija; Cooper, Andrew; Cumberland, Phillippa; Lewando-Hundt, Gillian; Rahi, Jugnoo S

    2013-12-01

    To develop a novel age-appropriate measure of functional vision (FV) for self-reporting by visually impaired (VI) children and young people. Questionnaire development. A representative patient sample of VI children and young people aged 10 to 15 years, visual acuity of the logarithm of the minimum angle of resolution (logMAR) worse than 0.48, and a school-based (nonrandom) expert group sample of VI students aged 12 to 17 years. A total of 32 qualitative semistructured interviews supplemented by narrative feedback from 15 eligible VI children and young people were used to generate draft instrument items. Seventeen VI students were consulted individually on item relevance and comprehensibility, instrument instructions, format, and administration methods. The resulting draft instrument was piloted with 101 VI children and young people comprising a nationally representative sample, drawn from 21 hospitals in the United Kingdom. Initial item reduction was informed by presence of missing data and individual item response pattern. Exploratory factor analysis (FA) and parallel analysis (PA), and Rasch analysis (RA) were applied to test the instrument's psychometric properties. Psychometric indices and validity assessment of the Functional Vision Questionnaire for Children and Young People (FVQ_CYP). A total of 712 qualitative statements became a 56-item draft scale, capturing the level of difficulty in performing vision-dependent activities. After piloting, items were removed iteratively as follows: 11 for high percentage of missing data, 4 for skewness, and 1 for inadequate item infit and outfit values in RA, 3 having shown differential item functioning across age groups and 1 across gender in RA. The remaining 36 items showed item fit values within acceptable limits, good measurement precision and targeting, and ordered response categories. The reduced scale has a clear unidimensional structure, with all items having a high factor loading on the single factor in FA and

  13. Combination of blood oxygen level–dependent functional magnetic resonance imaging and visual evoked potential recordings for abnormal visual cortex in two types of amblyopia

    Science.gov (United States)

    Wang, Xinmei; Cui, Dongmei; Zheng, Ling; Yang, Xiao; Yang, Hui

    2012-01-01

    Purpose To elucidate the different neuromechanisms of subjects with strabismic and anisometropic amblyopia compared with normal vision subjects using blood oxygen level–dependent functional magnetic resonance imaging (BOLD-fMRI) and pattern-reversal visual evoked potential (PR-VEP). Methods Fifty-three subjects, age range seven to 12 years, diagnosed with strabismic amblyopia (17 cases), anisometropic amblyopia (20 cases), and normal vision (16 cases), were examined using the BOLD-fMRI and PR-VEP of UTAS-E3000 techniques. Cortical activation by binocular viewing of reversal checkerboard patterns was examined in terms of the calcarine region of interest (ROI)-based and spatial frequency–dependent analysis. The correlation of cortical activation in fMRI and the P100 amplitude in VEP were analyzed using the SPSS 12.0 software package. Results In the BOLD-fMRI procedure, reduced areas and decreased activation levels were found in Brodmann area (BA) 17 and other extrastriate areas in subjects with amblyopia compared with the normal vision group. In general, the reduced areas mainly resided in the striate visual cortex in subjects with anisometropic amblyopia. In subjects with strabismic amblyopia, a more significant cortical impairment was found in bilateral BA 18 and BA 19 than that in subjects with anisometropic amblyopia. The activation by high-spatial-frequency stimuli was reduced in bilateral BA 18 and 19 as well as BA 17 in subjects with anisometropic amblyopia, whereas the activation was mainly reduced in BA 18 and BA 19 in subjects with strabismic amblyopia. These findings were further confirmed by the ROI-based analysis of BA 17. During spatial frequency–dependent VEP detection, subjects with anisometropic amblyopia had reduced sensitivity for high spatial frequency compared to subjects with strabismic amblyopia. The cortical activation in fMRI with the calcarine ROI-based analysis of BA 17 was significantly correlated with the P100 amplitude in VEP

  14. Neural Responses to Visual Food Cues According to Weight Status: A Systematic Review of Functional Magnetic Resonance Imaging Studies

    Science.gov (United States)

    Pursey, Kirrilly M.; Stanwell, Peter; Callister, Robert J.; Brain, Katherine; Collins, Clare E.; Burrows, Tracy L.

    2014-01-01

    Emerging evidence from recent neuroimaging studies suggests that specific food-related behaviors contribute to the development of obesity. The aim of this review was to report the neural responses to visual food cues, as assessed by functional magnetic resonance imaging (fMRI), in humans of differing weight status. Published studies to 2014 were retrieved and included if they used visual food cues, studied humans >18 years old, reported weight status, and included fMRI outcomes. Sixty studies were identified that investigated the neural responses of healthy weight participants (n = 26), healthy weight compared to obese participants (n = 17), and weight-loss interventions (n = 12). High-calorie food images were used in the majority of studies (n = 36), however, image selection justification was only provided in 19 studies. Obese individuals had increased activation of reward-related brain areas including the insula and orbitofrontal cortex in response to visual food cues compared to healthy weight individuals, and this was particularly evident in response to energy dense cues. Additionally, obese individuals were more responsive to food images when satiated. Meta-analysis of changes in neural activation post-weight loss revealed small areas of convergence across studies in brain areas related to emotion, memory, and learning, including the cingulate gyrus, lentiform nucleus, and precuneus. Differential activation patterns to visual food cues were observed between obese, healthy weight, and weight-loss populations. Future studies require standardization of nutrition variables and fMRI outcomes to enable more direct comparisons between studies. PMID:25988110

  15. Slow fluctuations in eye position and resting-state functional magnetic resonance imaging brain activity during visual fixation.

    Science.gov (United States)

    Fransson, Peter; Flodin, Pär; Seimyr, Gustaf Öqvist; Pansell, Tony

    2014-12-01

    The neuronal circuitry that supports voluntary changes in eye position in tasks that require attention-driven oculo-motor control is well known. However, less is known about the neuronal basis for eye control during visual fixation. This, together with the fact that visual fixation is one of the most commonly used baseline conditions in resting-state functional magnetic resonance imaging (fMRI) studies, prompted us to conduct a study in which we employed resting-state fMRI and concurrent recordings of eye gaze to investigate the relationship between spontaneous changes in eye position during passive visual fixation and intrinsic brain activity. As a control experiment, we recorded fMRI brain activity related to cued voluntary vertical and horizontal changes in eye position in a block-related task-evoked fMRI experiment. Our results for the voluntarily performed changes in eye position elicited brain activity in the bilateral occipitotemporal cortex, supplementary motor cortex and frontal eye fields. In contrast, we show that slow fluctuations in eye position during passive visual fixation are linked to intrinsic brain activity, foremost in midline cortical brain regions located in the posteromedial parietal cortex and the medial prefrontal cortex, brain regions that act as core cortical hubs in the brain's default mode network. Our results suggest that subconscious and sustained changes in behavior are tied to intrinsic brain activity on a moment-by-moment basis. © 2014 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  16. Neural responses to visual food cues according to weight status: a systematic review of functional magnetic resonance imaging studies.

    Science.gov (United States)

    Pursey, Kirrilly M; Stanwell, Peter; Callister, Robert J; Brain, Katherine; Collins, Clare E; Burrows, Tracy L

    2014-01-01

    Emerging evidence from recent neuroimaging studies suggests that specific food-related behaviors contribute to the development of obesity. The aim of this review was to report the neural responses to visual food cues, as assessed by functional magnetic resonance imaging (fMRI), in humans of differing weight status. Published studies to 2014 were retrieved and included if they used visual food cues, studied humans >18 years old, reported weight status, and included fMRI outcomes. Sixty studies were identified that investigated the neural responses of healthy weight participants (n = 26), healthy weight compared to obese participants (n = 17), and weight-loss interventions (n = 12). High-calorie food images were used in the majority of studies (n = 36), however, image selection justification was only provided in 19 studies. Obese individuals had increased activation of reward-related brain areas including the insula and orbitofrontal cortex in response to visual food cues compared to healthy weight individuals, and this was particularly evident in response to energy dense cues. Additionally, obese individuals were more responsive to food images when satiated. Meta-analysis of changes in neural activation post-weight loss revealed small areas of convergence across studies in brain areas related to emotion, memory, and learning, including the cingulate gyrus, lentiform nucleus, and precuneus. Differential activation patterns to visual food cues were observed between obese, healthy weight, and weight-loss populations. Future studies require standardization of nutrition variables and fMRI outcomes to enable more direct comparisons between studies.

  17. Changes in visual function and thickness of macula after photodynamic therapy for age-related macular degeneration

    Directory of Open Access Journals (Sweden)

    Kyoko Okada

    2009-09-01

    Full Text Available Kyoko Okada, Mariko Kubota-Taniai, Masayasu Kitahashi, Takayuki Baba, Yoshinori Mitamura, Shuichi YamamotoDepartment of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, JapanPurpose: To determine the correlation between the changes in the central retinal sensitivity and the changes in the foveal thickness (FT after photodynamic therapy (PDT for age-related macular degeneration (AMD.Methods: Nineteen eyes of 19 patients with choroidal neovasularizations (CNVs secondary to AMD were studied. The pretreatment values of the central retinal sensitivity determined by Micro Perimeter 1 (MP1; Nidek Technologies, best-corrected visual acuity (BCVA, and optical coherence tomography (OCT-determined FT were compared to the postoperative values at three and six months after PDT.Results: At six months, the retinal sensitivity within the central 10° was significantly improved (P = 0.02 and the FT was significantly thinner (P = 0.016. The BCVA, however, did not change significantly (P = 0.80. The changes in the retinal sensitivities were significantly correlated with the changes in the decrease in the FT (r = -0.59, P = 0.012 within the central 10° at six months after PDT.Conclusion: Significant improvements in retinal sensitivities within the central 10° and a decrease in FT were observed even though the BCVA was not significantly improved. The measurement of retinal sensitivity by MP1 may be a better method to assess central visual function than the conventional visual acuity after PDT.Keywords: age-related macular degeneration, fundus-related microperimetry, optical coherence tomography, photodynamic therapy

  18. Relationships between activities of daily living, upper limb function, and visual perception in children and adolescents with unilateral cerebral palsy

    National Research Council Canada - National Science Library

    James, Sarah; Ziviani, Jenny; Ware, Robert S; Boyd, Roslyn N

    2015-01-01

    ...) motor skills in children with unilateral cerebral palsy. Visual perception ability, most significantly sequential memory and visual closure, are associated with ADL process skills. There is 65...

  19. Frequency and Correlates of Distant Visual Impairment in Patients with Schizophrenia, Bipolar Disorder, and Major Depressive Disorder.

    Science.gov (United States)

    Zheng, W; Tang, L R; Correll, C U; Ungvari, G S; Chiu, H F K; Xiang, Y Q; Xiang, Y T

    2015-09-01

    Distant visual impairment in the severely mentally ill is under-researched. This study aimed to assess the frequency and correlates of distant visual impairment in a cohort of Chinese psychiatric patients, including its effect on their quality of life. Adult psychiatric inpatients with schizophrenia, bipolar disorder, and major depressive disorder consecutively admitted to a psychiatric hospital in Beijing, China underwent assessments of psychopathology (Brief Psychiatric Rating Scale, 16-item Quick Inventory of Depressive Symptomatology [Self-Report]), quality of life (12-item Short-Form Medical Outcomes Study [SF-12], 25-item National Eye Institute Visual Function Questionnaire [NEI-VFQ25]), adverse effects (Udvalg for Kliniske Undersøgelser Side Effect Rating Scale), and presenting (as opposed to uncorrected) distant visual acuity (Logarithm of the Minimum Angle of Resolution [LogMAR] chart with patients wearing spectacles, if they owned them). Distant visual impairment was defined as binocular distant visual acuity of a LogMAR score of ≥ 0.5 (visual impairment was 12.6% (15.2% with schizophrenia, 11.9% with bipolar disorder, 8.8% with major depressive disorder). In multiple logistic regression analysis, distant visual impairment was significantly associated with ocular disease only (p = 0.002, odds ratio = 3.2, 95% confidence interval = 1.5-6.7). Controlling for the confounding effect of ocular disease, patients with distant visual impairment had a lower quality of life in the general vision domain of the NEI-VFQ25 (F[2, 353] = 9.5, p = 0.002) compared with those without. No differences in the physical and mental domains of the SF-12 and in other domains of the NEI-VFQ25 were noted in these 2 groups. One-eighth of middle-aged severely mentally ill patients had distant visual impairment. Considering the impact of distant visual impairment on daily functioning, severely mentally ill patients need to be screened for impaired eyesight as part of their

  20. Target-present guessing as a function of target prevalence and accumulated information in visual search.

    Science.gov (United States)

    Peltier, Chad; Becker, Mark W

    2017-05-01

    Target prevalence influences visual search behavior. At low target prevalence, miss rates are high and false alarms are low, while the opposite is true at high prevalence. Several models of search aim to describe search behavior, one of which has been specifically intended to model search at varying prevalence levels. The multiple decision model (Wolfe & Van Wert, Current Biology, 20(2), 121--124, 2010) posits that all searches that end before the observer detects a target result in a target-absent response. However, researchers have found very high false alarms in high-prevalence searches, suggesting that prevalence rates may be used as a source of information to make "educated guesses" after search termination. Here, we further examine the ability for prevalence level and knowledge gained during visual search to influence guessing rates. We manipulate target prevalence and the amount of information that an observer accumulates about a search display prior to making a response to test if these sources of evidence are used to inform target present guess rates. We find that observers use both information about target prevalence rates and information about the proportion of the array inspected prior to making a response allowing them to make an informed and statistically driven guess about the target's presence.

  1. Functional differentiation of macaque visual temporal cortical neurons using a parametric action space.

    Science.gov (United States)

    Vangeneugden, Joris; Pollick, Frank; Vogels, Rufin

    2009-03-01

    Neurons in the rostral superior temporal sulcus (STS) are responsive to displays of body movements. We employed a parametric action space to determine how similarities among actions are represented by visual temporal neurons and how form and motion information contributes to their responses. The stimulus space consisted of a stick-plus-point-light figure performing arm actions and their blends. Multidimensional scaling showed that the responses of temporal neurons represented the ordinal similarity between these actions. Further tests distinguished neurons responding equally strongly to static presentations and to actions ("snapshot" neurons), from those responding much less strongly to static presentations, but responding well when motion was present ("motion" neurons). The "motion" neurons were predominantly found in the upper bank/fundus of the STS, and "snapshot" neurons in the lower bank of the STS and inferior temporal convexity. Most "motion" neurons showed strong response modulation during the course of an action, thus responding to action kinematics. "Motion" neurons displayed a greater average selectivity for these simple arm actions than did "snapshot" neurons. We suggest that the "motion" neurons code for visual kinematics, whereas the "snapshot" neurons code for form/posture, and that both can contribute to action recognition, in agreement with computation models of action recognition.

  2. Visualizing olfactory learning functional imaging of experience-induced olfactory bulb changes.

    Science.gov (United States)

    Fletcher, Max L; Bendahmane, Mounir

    2014-01-01

    The anatomical organization of sensory neuron input allows odor information to be transformed into odorant-specific spatial maps of mitral/tufted cell glomerular activity. In other sensory systems, neuronal representations of sensory stimuli can be reorganized or enhanced following learning or experience. Similarly, several studies have demonstrated both structural and physiological experience-induced changes throughout the olfactory system. As experience-induced changes within this circuit likely serve as an initial site for odor memory formation, the olfactory bulb is an ideal site for optical imaging studies of olfactory learning, as they allow for the visualization of experience-induced changes in the glomerular circuit following learning and how these changes impact of odor representations with the bulb. Presently, optical imaging techniques have been used to visualize experience-induced changes in glomerular odor representations in a variety of paradigms in short-term habituation, chronic odor exposure, and olfactory associative conditioning. © 2014 Elsevier B.V. All rights reserved.

  3. Functional asymmetry in sensory discrimination in visually blind and its association to braille reading

    Directory of Open Access Journals (Sweden)

    Rohan P.Choraghe

    2015-12-01

    Results: Most participants (n=44 chose finger from right hand as preferred finger for braille reading; this was unrelated to motor handedness. In visually blind population average values of 2PD in right hand was significantly (p<0.001 less than right. In normal visioned subjects there was no significant difference in sensory discrimination between right and left hand. Conclusions: Due to presence of language areas in left hemisphere (90-92% of people, all our language related modalities are inclined toward left hemisphere. Here we proved that blind people prefer right hand over left hand while reading written braille language and thus have better sensory discrimination for same. Previous studies have shown that blindness itself acts as stimulus to activate latent pathways (cross-modal plasticity between somatosensory cortex, visual cortex and language areas. Overall we tried to prove brain is hardwired to do all language related activities preferably with right hand. [Int J Res Med Sci 2015; 3(12.000: 3530-3533

  4. Effect of Visual Impairment on Physical and Cognitive Function in Old Age: Findings of a Population-Based Prospective Cohort Study in Germany.

    Science.gov (United States)

    Hajek, André; Brettschneider, Christian; Lühmann, Dagmar; Eisele, Marion; Mamone, Silke; Wiese, Birgitt; Weyerer, Siegfried; Werle, Jochen; Pentzek, Michael; Fuchs, Angela; Riedel-Heller, Steffi G; Luck, Tobias; Bickel, Horst; Weeg, Dagmar; Koppara, Alexander; Wagner, Michael; Scherer, Martin; Maier, Wolfgang; König, Hans-Helmut

    2016-11-01

    To examine how visual impairment affects physical and cognitive function in old age. A longitudinal population-based prospective cohort study. General practitioner offices at six study centers in Germany. They were observed every 1.5 years over four waves. Individuals aged 77-101 at follow-up Wave 2 (N = 2,394). Physical and cognitive function were assessed using an adapted scale that had been previously developed, and visual impairment was rated on a Likert scale (none, mild, severe or profound). Adjusting for sociodemographic factors and comorbidity, linear fixed-effects regression showed that the onset of severe visual impairment was associated with a decline in physical function score in the total sample (β = -0.15, P = .01) and in women (β = -.15, P = .03). Moreover, the onset of severe visual impairment was associated with decline in cognitive function score in the total sample (β = -0.38, P Visual impairment affects physical and cognitive function in old age. Interventional strategies to postpone visual impairment may contribute to maintaining physical and cognitive function. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

  5. Health-related quality of life, visual function and treatment satisfaction following intravitreal dexamethasone implant for diabetic macular edema

    Science.gov (United States)

    Ramu, Jayashree; Chatziralli, Irini; Yang, Yit; Menon, Geeta; Bailey, Clare; Eckstein, Michael; Hykin, Phil; Sivaprasad, Sobha

    2017-01-01

    Purpose The aim of this study was to explore and describe quantitatively patient-reported outcome measures (PROMs), ie, health-related quality of life (QoL), visual function and treatment satisfaction, in patients with diabetic macular edema (DME) receiving two different regimens of Ozurdex (intravitreal dexamethasone implant). Methods In this multicenter, prospective study, 100 patients with center-involving refractory DME were randomized 1:1 to either five monthly fixed dosing or optical coherence tomography (OCT)-guided pro re nata (PRN) regimen of dexamethasone intravitreal implant therapy. The primary outcome was the difference between arms in change in PROMs and health-related QoL from baseline to 12 months, as measured by the Retinopathy-Dependent Quality of Life (RetDQoL) questionnaire, Visual Function Questionnaire-25 (VFQ-25) and Retinopathy Treatme