WorldWideScience

Sample records for 25-item visual function

  1. Vision-Related Quality of Life and Visual Function Following Vitrectomy for Proliferative Diabetic Retinopathy

    Okamoto, Fumiki; Okamoto, Yoshifumi; Fukuda, Shinichi; Hiraoka, Takahiro; Oshika, Tetsuro

    2008-01-01

    PurposeTo evaluate the vision-related quality of life (VR-QOL) and visual function following vitrectomy for proliferative diabetic retinopathy (PDR).DesignProspective, interventional, consecutive, comparative case series.MethodsThe 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25) was answered by 51 patients with PDR before and three months after 20-gauge pars plana vitrectomy. Among the patients with PDR, 30 underwent combined cataract surgery and vitrectomy. Clinical dat...

  2. Functional magnetic resonance imaging by visual stimulation

    We evaluated functional magnetic resonance images obtained in 8 healthy subjects in response to visual stimulation using a conventional clinical magnetic resonance imaging system with multi-slice spin-echo echo planar imaging. Activation in the visual cortex was clearly demonstrated by the multi-slice experiment with a task-related change in signal intensity. In addition to the primary visual cortex, other areas were also activated by a complicated visual task. Multi-slice spin-echo echo planar imaging offers high temporal resolution and allows the three-dimensional analysis of brain function. Functional magnetic resonance imaging provides a useful noninvasive method of mapping brain function. (author)

  3. Visual Function in Geriatric Eye Disease

    Faye, Eleanor E.

    1971-01-01

    Visual functioning, treatment, and helpful low vision aids are discussed in relation to four major eye diseases of the elderly: cataract, macular degeneration, glaucoma, and diabetic retinopathy. (KW)

  4. Functional Visual Acuity of Early Presbyopia

    Katada, Yusaku; Negishi, Kazuno; Watanabe, Kazuhiro; Shigeno, Yuta; Saiki, Megumi; Torii, Hidemasa; Kaido, Minako; Tsubota, Kazuo

    2016-01-01

    Purpose To evaluate visual function in patients with early presbyopia using the functional visual acuity (FVA) test. Methods This study included 27 eyes of 27 healthy older volunteers (mean age, 44.1 ± 2.6 years) and 14 eyes of 14 healthy young volunteers (mean age, 28.4±4.8 years). The distance-corrected visual acuity (DCVA), distance-corrected near VA (DCNVA), subjective amplitude of accommodation (AA), and distance and near pupillary diameters were measured. The distance FVA and distance-c...

  5. Reliability, Validity, and Predictive Utility of the 25-Item Criminogenic Cognitions Scale (CCS).

    Tangney, June Price; Stuewig, Jeffrey; Furukawa, Emi; Kopelovich, Sarah; Meyer, Patrick; Cosby, Brandon

    2012-10-01

    Theory, research, and clinical reports suggest that moral cognitions play a role in initiating and sustaining criminal behavior. The 25 item Criminogenic Cognitions Scale (CCS) was designed to tap 5 dimensions: Notions of entitlement; Failure to Accept Responsibility; Short-Term Orientation; Insensitivity to Impact of Crime; and Negative Attitudes Toward Authority. Results from 552 jail inmates support the reliability, validity, and predictive utility of the measure. The CCS was linked to criminal justice system involvement, self-report measures of aggression, impulsivity, and lack of empathy. Additionally, the CCS was associated with violent criminal history, antisocial personality, and clinicians' ratings of risk for future violence and psychopathy (PCL:SV). Furthermore, criminogenic thinking upon incarceration predicted subsequent official reports of inmate misconduct during incarceration. CCS scores varied somewhat by gender and race. Research and applied uses of CCS are discussed. PMID:24072946

  6. Imaging visual function of the human brain

    Imaging of human brain structure and activity with particular reference to visual function is reviewed along with methods of obtaining the data including computed tomographic (CT) scan, magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and positron emission tomography (PET). The literature is reviewed and the potential for a new understanding of brain visual function is discussed. PET is reviewed from basic physical principles to the most recent visual brain findings with oxygen-15. It is shown that there is a potential for submillimeter localization of visual functions with sequentially different visual stimuli designed for the temporal separation of the responses. Single photon emission computed tomography (SPECT), a less expensive substitute for PET, is also discussed. MRS is covered from basic physical principles to the current state of the art of in vivo biochemical analysis. Future possible clinical applications are discussed. Improved understanding of the functional neural organization of vision and brain will open a window to maps and circuits of human brain function.119 references

  7. Functional visual disturbance due to hysteria.

    Lai, Hui-Chun; Lin, Ken-Kuo; Yang, Meng-Ling; Chen, Henry Shen-Lih

    2007-01-01

    A 23-year-old male complained of loss of peripheral visual field and everything having purple shadows in the afternoon. This had lasted for 3 years but he had paid little attention to the symptoms. Investigations, including visual acuity, intra-ocular pressure, pupil reflex, and anterior and posterior segment of the eyes, were normal. He denied ocular pain, history of head injury, epilepsy or related family history. The Goldmann perimeter and tangent screen examinations showed a bilateral constricted tubular visual field defect within the central 10 degrees and steep margins. Tracing his past social history, he had been in jail for 3 months. He also complained his work was hard and caused him tension. The visual symptoms were a functional disturbance, not an organic disorder. We diagnosed him with hysterical functional visual disturbance. Hysteria, or conversion disorder, has long been a puzzling and fascinating problem in psychology and ophthalmology. The mechanism and reasons for hysteria are still not clear. The tangent screen is useful in diagnosis. The constricted tubular, spiral or star-shaped visual fields with steep slopes are specific findings in hysteria. We suggest that ophthalmologists should treat patients with psychogenic symptoms, using suggestion, patience and reassurance. PMID:17477034

  8. Mathematical modeling and visualization of functional neuroimages

    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...... be carefully selected, so that the model and its visualization enhance our ability to interpret brain function. The second part concerns interpretation of nonlinear models and procedures for extraction of ‘brain maps’ from nonlinear kernel models. We assess the performance of the sensitivity map as...... means for extracting a global summary map from a trained model. Such summary maps provides the investigator with an overview of brain locations of importance to the model’s predictions. The sensitivity map proves as a versatile technique for model visualization. Furthermore, we perform a preliminary...

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

    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. PMID:26209358

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

    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.

  11. Confidence, Visual Research, and the Aesthetic Function

    Stan Ruecker

    2007-05-01

    Full Text Available The goal of this article is to identify and describe one of the primary purposes of aesthetic quality in the design of computer interfaces and visualization tools. We suggest that humanists can derive advantages in visual research by acknowledging by their efforts to advance aesthetic quality that a significant function of aesthetics in this context is to inspire the user’s confidence. This confidence typically serves to create a sense of trust in the provider of the interface or tool. In turn, this increased trust may result in an increased willingness to engage with the object, on the basis that it demonstrates an attention to detail that promises to reward increased engagement. In addition to confidence, the aesthetic may also contribute to a heightened degree of satisfaction with having spent time using or investigating the object. In the realm of interface design and visualization research, we propose that these aesthetic functions have implications not only for the quality of interactions, but also for the results of the standard measures of performance and preference.

  12. Mathematical modeling and visualization of functional neuroimages

    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...... parameters must be carefully selected, so that the model and its visualization enhance our ability to interpret the brain. The second part concerns interpretation of nonlinear models and procedures for extraction of ‘brain maps’ from nonlinear kernel models. We assess the performance of the sensitivity map...... as means for extracting a global summary map from a trained model. Such summary maps provides the investigator with an overview of brain locations of importance to the model’s predictions. The sensitivity map proves as a versatile technique for model visualization. Furthermore, we perform a...

  13. Visual Function following Treatment of Optic Neuritis

    Majid Abrishami

    2008-12-01

    Full Text Available

    PURPOSE: To evaluate changes in different aspects of visual function including visual acuity, visual field, contrast sensitivity, colour vision and stereopsis in patients with optic neuritis before and after medical intervention. METHODS: In a noncomparative interventional case series on 31 eyes of 30 patients with optic neuritis, the following aspects of visual function were compared before and after treatment. Medical intervention was conducted following the Optic Neuritis Treatment Trial (ONTT guidelines. Visual function was assessed by evaluating changes in visual acuity, visual field (Goldmann in all patients and automated in some patients, contrast sensitivity using Cambridge low contrast grating, colour vision using Ishihara plates and stereopsis using Titmus stereoacuity test. RESULTS: Visual acuity was significantly lower (3/10 in the affected eyes than unaffected eyes (8/10 [P < 0.001]. Contrast sensitivity was also significantly better in the unaffected eyes. Mean stereoacuity was 310 sec/arc. The visual field impairment was also significantly higher than that of the unaffected eye and also normal population sample. Weak deutan defects were present in 60% of the patients. After medical treatment, visual acuity, visual field defects, contrast sensitivity, colour and stereopsis were significantly improved

  14. Visual space perception: phenomenology and function

    Jack M. Loomis

    2003-01-01

    Full Text Available This article presents a brief overview of visual space perception. It begins by noting the significance of visual space perception to broader issues in philosophy and science and observes that the appreciation of visual space perception as a scientific topic is impeded by naïve realism. The second section notes the longstanding interest in the phenomenology of visual space and focuses on one issue, the dissocation between perceived location and perceived shape in visual space. The last section discusses three conceptions of how vision controls action, with special attention to the role of visual space.

  15. Functional Visual Disturbance due to Hysteria

    Hui-Chun Lai; Ken-Kuo Lin; Meng-Ling Yang; Henry Shen-Lih Chen

    2007-01-01

    A 23-year-old male complained of loss of peripheral visual field and everything havingpurple shadows in the afternoon. This had lasted for 3 years but he had paid little attention tothe symptoms. Investigations, including visual acuity, intra-ocular pressure, pupil reflex, andanterior and posterior segment of the eyes, were normal. He denied ocular pain, history ofhead injury, epilepsy or related family history. The Goldmann perimeter and tangent screenexaminations showed a bilateral constric...

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

    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. PMID:26802723

  17. Visual Plasticity: Blindsight Bridges Anatomy and Function in the Visual System.

    Tamietto, Marco; Morrone, Maria Concetta

    2016-01-25

    Some people who are blind due to damage to their primary visual cortex, V1, can discriminate stimuli presented within their blind visual field. This residual function has been recently linked to a pathway that bypasses V1, and connects the thalamic lateral geniculate nucleus directly with the extrastriate cortical area MT. PMID:26811892

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

    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.

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

    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 ...

  20. Alzheimer disease: functional abnormalities in the dorsal visual pathway.

    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.

  1. Adaptive tuning functions arise from visual observation of past movement.

    Howard, Ian S; Franklin, David W

    2016-01-01

    Visual observation of movement plays a key role in action. For example, tennis players have little time to react to the ball, but still need to prepare the appropriate stroke. Therefore, it might be useful to use visual information about the ball trajectory to recall a specific motor memory. Past visual observation of movement (as well as passive and active arm movement) affects the learning and recall of motor memories. Moreover, when passive or active, these past contextual movements exhibit generalization (or tuning) across movement directions. Here we extend this work, examining whether visual motion also exhibits similar generalization across movement directions and whether such generalization functions can explain patterns of interference. Both the adaptation movement and contextual movement exhibited generalization beyond the training direction, with the visual contextual motion exhibiting much broader tuning. A second experiment demonstrated that this pattern was consistent with the results of an interference experiment where opposing force fields were associated with two separate visual movements. Overall, our study shows that visual contextual motion exhibits much broader (and shallower) tuning functions than previously seen for either passive or active movements, demonstrating that the tuning characteristics of past motion are highly dependent on their sensory modality. PMID:27341163

  2. Visual functional changes during acute elevation of intraocular pressure

    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.

  3. Effect of visual training on cognitive function in stroke patients

    Chang-Xiang Chen; Rong-Hua Mao; Shu-Xing Li; Ya-Ning Zhao; Min Zhang

    2015-01-01

    Objective: To observe the effect of visual training on cognitive function in stoke patients. Methods: Eighty stroke patients with cognitive dysfunction were divided into two groups (n = 40 in each group). The control group received conventional rehabilitation therapies. The experimental group received visual training in addition to the conventional therapies. This training was administered for 30 min once a day, five times a week, for four weeks. All patients were screened with the Montrea...

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

    Langkilde, Annika Reynberg; Frederiksen, J.L.; Rostrup, Egill; Larsson, H.B.W.

    2002-01-01

    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...... 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......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...

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

    Langkilde, Annika Reynberg; Frederiksen, J.L.; Rostrup, Egill; Larsson, H.B.W.

    2002-01-01

    significantly 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...

  6. Low-level laser Effects On Rhesus Visual Function

    Zwick, Harry; Stuck, Bruce E.; Beatrice, Edwin S.

    1980-10-01

    Although present laser safety standards are based on an adequate data base for acute viewing situations, they are limited in predicting the type of change in visual function that might be induced from prolonged or repetitive viewing of laser sources. Viewing requirements in holography, laser display systems, and, in general, repeated exposure to low levels of laser radiation require a more complete data base for optimizing the environmental protection of individuals who will be required to work in such environments. In these studies, we have simulated very low-level radiation environments and determined the effects of repetitive prolonged exposure on the visual function of the Rhesus. Our data suggest that prolonged viewing of such sources, even though they are well below present laser safety standards, can produce permanent changes in visual processes that underlie normal human day (photopic) and night (scotopic) vision, although preliminary studies of morphology have shown no morphological correlate. The coherency of laser light is implicated as a significant factor in inducing these effects. It is recommended that individuals required to work in these situations be frequently evaluated for changes in visual function by presently available clinical instruments for assessment of visual function. Further confirmation of these studies will determine the impact of these research findings on present laser safety standards.

  7. Visualizing and Clustering Protein Similarity Networks: Sequences, Structures, and Functions.

    Mai, Te-Lun; Hu, Geng-Ming; Chen, Chi-Ming

    2016-07-01

    Research in the recent decade has demonstrated the usefulness of protein network knowledge in furthering the study of molecular evolution of proteins, understanding the robustness of cells to perturbation, and annotating new protein functions. In this study, we aimed to provide a general clustering approach to visualize the sequence-structure-function relationship of protein networks, and investigate possible causes for inconsistency in the protein classifications based on sequences, structures, and functions. Such visualization of protein networks could facilitate our understanding of the overall relationship among proteins and help researchers comprehend various protein databases. As a demonstration, we clustered 1437 enzymes by their sequences and structures using the minimum span clustering (MSC) method. The general structure of this protein network was delineated at two clustering resolutions, and the second level MSC clustering was found to be highly similar to existing enzyme classifications. The clustering of these enzymes based on sequence, structure, and function information is consistent with each other. For proteases, the Jaccard's similarity coefficient is 0.86 between sequence and function classifications, 0.82 between sequence and structure classifications, and 0.78 between structure and function classifications. From our clustering results, we discussed possible examples of divergent evolution and convergent evolution of enzymes. Our clustering approach provides a panoramic view of the sequence-structure-function network of proteins, helps visualize the relation between related proteins intuitively, and is useful in predicting the structure and function of newly determined protein sequences. PMID:27267620

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

    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. PMID:26275965

  9. Visualizing Exact and Approximated 3D Empirical Attainment Functions

    Tea Tušar

    2014-01-01

    Full Text Available Most real-world engineering optimization problems are inherently multiobjective, for example, searching for trade-off solutions of high quality and low cost. As no single optimal solution exists for such problems, multiobjective optimizers provide sets of optimal (or near-optimal trade-off solutions to choose from. The empirical attainment function (EAF is a powerful tool that can be used to analyze and compare the performance of these optimizers. While the visualization of EAFs is rather straightforward in two objectives, the three-objective case presents a great challenge as we need to visualize a large number of 3D cuboids. This paper addresses the visualization of exact as well as approximated 3D EAF values and differences in these values provided by two competing multiobjective optimizers. We show that the exact EAFs can be visualized using slicing and maximum intensity projection (MIP, while the approximated EAFs can be visualized using slicing, MIP, and direct volume rendering. In addition, the paper demonstrates the use of the proposed visualization techniques on a steel casting optimization problem.

  10. Restoration of Visual Function by Enhancing Conduction in Regenerated Axons.

    Bei, Fengfeng; Lee, Henry Hing Cheong; Liu, Xuefeng; Gunner, Georgia; Jin, Hai; Ma, Long; Wang, Chen; Hou, Lijun; Hensch, Takao K; Frank, Eric; Sanes, Joshua R; Chen, Chinfei; Fagiolini, Michela; He, Zhigang

    2016-01-14

    Although a number of repair strategies have been shown to promote axon outgrowth following neuronal injury in the mammalian CNS, it remains unclear whether regenerated axons establish functional synapses and support behavior. Here, in both juvenile and adult mice, we show that either PTEN and SOCS3 co-deletion, or co-overexpression of osteopontin (OPN)/insulin-like growth factor 1 (IGF1)/ciliary neurotrophic factor (CNTF), induces regrowth of retinal axons and formation of functional synapses in the superior colliculus (SC) but not significant recovery of visual function. Further analyses suggest that regenerated axons fail to conduct action potentials from the eye to the SC due to lack of myelination. Consistent with this idea, administration of voltage-gated potassium channel blockers restores conduction and results in increased visual acuity. Thus, enhancing both regeneration and conduction effectively improves function after retinal axon injury. PMID:26771493

  11. Dyspraxia, Motor Function and Visual-Motor Integration in Autism

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

    2014-01-01

    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 B...

  12. An automated miniaturized Haploscope for testing binocular visual function

    Decker, T. A.; Williams, R. E.; Kuether, C. L.; Wyman-Cornsweet, D.

    1976-01-01

    A computer-controlled binocular vision testing device has been developed as one part of a system designed for NASA to test the vision of astronauts during spaceflight. The device, called the Mark III Haploscope, utilizes semi-automated psychophysical test procedures to measure visual acuity, stereopsis, phorias, fixation disparity and accommodation/convergence relationships. All tests are self-administered, yield quantitative data and may be used repeatedly without subject memorization. Future applications of this programmable, compact device include its use as a clinical instrument to perform routine eye examinations or vision screening, and as a research tool to examine the effects of environment or work-cycle upon visual function.

  13. Visual Functioning of Individuals and Communities: A Conceptual Framework

    Joann Giaconi

    2008-01-01

    Full Text Available The prevalence of visual impairment and blindness increases dramatically with advancing age. The major diseases that cause visual impairment and blindness, specifically cataract, macular degeneration, and glaucoma, are age-related. The number of visually impaired Americans older than 40 years is projected to double by 2030. Half of all cases of blindness may be preventable. Research in the area of vision has developed into ophthalmologically defined silos that follow specific diseases or study subparts of the eye. To overcome the limitations of current subspecialty conceptualization of vision problems, it is necessary to develop new models that can expand the current research paradigms in new directions. This review paper details literature within a conceptual model to explain the increases in visual impairment, the age and other demo- graphic disparities in prevalence, and the lack of vision screening, treatment, and rehabilitation. At the core of the conceptual framework are the twin phenomena of vision health as perceived by the individual and vision health as clinically-measured. Other domains of the framework include adaptation, vision demands, quality of life, and cues to using vision services such as access to care and social support. The framework incorporates multiple demographic, behavioral, and social factors that influence the vision health of individuals and communities. Areas of future research include population-based study of the knowledge, attitudes, and practices regarding vision health among both individuals and providers and multi-pronged interventions aimed at the individual, provider, organizational, and community levels to improve visual function.

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

    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. PMID:24937013

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

    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. PMID:24742861

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

    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.

  17. Glial cell development and function in the Drosophila visual system

    CHOTARD, CAROLE; Salecker, Iris

    2007-01-01

    In the developing nervous system, building a functional neuronal network relies on coordinating the formation, specification and survival to diverse neuronal and glial cell subtypes. The establishment of neuronal connections further depends on sequential neuron–neuron and neuron–glia interactions that regulate cell-migration patterns and axon guidance. The visual system of Drosophila has a highly regular, retinotopic organization into reiterated interconnected synaptic circuits. It is therefo...

  18. Visualization of genetic algorithm operation on additive decomposable functions

    Miquelina, Pedro Filipe Pereira

    2013-01-01

    In the past few years, there's been a growing interest in understanding genetic algorithm behavior and problem landscapes through visualization methods. This thesis tries to give an introduction to genetic algorithms and their theory, and describes a tool that attempts to better illustrate some of the important theoretical aspects behind a genetic algorithm, operating on additive decomposable functions, through the use of black and white images, in the form of an animation. Since these theore...

  19. Balance Functional Assessment in People with Visual Impairment

    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.

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

    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. PMID:27051066

  1. Dynamic Visual Acuity: a Functionally Relevant Research Tool

    Peters, Brian T.; Brady, Rachel A.; Miller, Chris A.; Mulavara, Ajitkumar P.; Wood, Scott J.; Cohen, Helen S.; Bloomberg, Jacob J.

    2010-01-01

    Coordinated movements between the eyes and head are required to maintain a stable retinal image during head and body motion. The vestibulo-ocular reflex (VOR) plays a significant role in this gaze control system that functions well for most daily activities. However, certain environmental conditions or interruptions in normal VOR function can lead to inadequate ocular compensation, resulting in oscillopsia, or blurred vision. It is therefore possible to use acuity to determine when the environmental conditions, VOR function, or the combination of the two is not conductive for maintaining clear vision. Over several years we have designed and tested several tests of dynamic visual acuity (DVA). Early tests used the difference between standing and walking acuity to assess decrements in the gaze stabilization system after spaceflight. Supporting ground-based studies measured the responses from patients with bilateral vestibular dysfunction and explored the effects of visual target viewing distance and gait cycle events on walking acuity. Results from these studies show that DVA is affected by spaceflight, is degraded in patients with vestibular dysfunction, changes with target distance, and is not consistent across the gait cycle. We have recently expanded our research to include studies in which seated subjects are translated or rotated passively. Preliminary results from this work indicate that gaze stabilization ability may differ between similar active and passive conditions, may change with age, and can be affected by the location of the visual target with respect to the axis of motion. Use of DVA as a diagnostic tool is becoming more popular but the functional nature of the acuity outcome measure also makes it ideal for identifying conditions that could lead to degraded vision. By doing so, steps can be taken to alter the problematic environments to improve the man-machine interface and optimize performance.

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

    Ingerslev, Mattias; Oliver Jespersen, Mikkel; Göhler, Simon Moritz; Howard, Thomas J.

    2015-01-01

    novel way 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...... 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...... within a product that can be used to estimate higher level consequences when making design changes. The diagram has further been used as a basis for evaluating the criticality of internal parts and functional organs....

  3. INTERACTIVE VISUALIZATION OF PROBABILITY AND CUMULATIVE DENSITY FUNCTIONS

    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.

  4. Systematic Functional Annotation and Visualization of Biological Networks.

    Baryshnikova, Anastasia

    2016-06-22

    Large-scale biological networks represent relationships between genes, but our understanding of how networks are functionally organized is limited. Here, I describe spatial analysis of functional enrichment (SAFE), a systematic method for annotating biological networks and examining their functional organization. SAFE visualizes the network in 2D space and measures the continuous distribution of functional enrichment across local neighborhoods, producing a list of the associated functions and a map of their relative positioning. I applied SAFE to annotate the Saccharomyces cerevisiae genetic interaction similarity network and protein-protein interaction network with gene ontology terms. SAFE annotations of the genetic network matched manually derived annotations, while taking less than 1% of the time, and proved robust to noise and sensitive to biological signal. Integration of genetic interaction and chemical genomics data using SAFE revealed a link between vesicle-mediate transport and resistance to the anti-cancer drug bortezomib. These results demonstrate the utility of SAFE for examining biological networks and understanding their functional organization. PMID:27237738

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

    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. PMID:26905288

  6. Visualization of group inference data in functional neuroimaging.

    Gläscher, Jan

    2009-01-01

    While thresholded statistical parametric maps can convey an accurate account for the location and spatial extent of an effect in functional neuroimaging studies, their use is somewhat limited for characterizing more complex experimental effects, such as interactions in a factorial design. The resulting necessity for plotting the underlying data has long been recognized. Statistical Parametric Mapping (SPM) is a widely used software package for analyzing functional neuroimaging data that offers a variety of options for visualizing data from first level analyses. However, nowadays, the thrust of the statistical inference lies at the second level thus allowing for population inference. Unfortunately, the options for visualizing data from second level analyses are quite sparse. rfxplot is a new toolbox designed to alleviate this problem by providing a comprehensive array of options for plotting data from within second level analyses in SPM. These include graphs of average effect sizes (across subjects), averaged fitted responses and event-related blood oxygen level-dependent (BOLD) time courses. All data are retrieved from the underlying first level analyses and voxel selection can be tailored to the maximum effect in each subject within a defined search volume. All plot configurations can be easily configured via a graphical user-interface as well as non-interactively via a script. The large variety of plot options renders rfxplot suitable both for data exploration as well as producing high-quality figures for publications. PMID:19140033

  7. Visual and motor functions in graphically gifted savants.

    Hermelin, B; Pring, L; Heavey, L

    1994-08-01

    Savant artists represent a conundrum to our understanding of the nature of high level specific talents as well as to the concept of general intellectual impairment. In the present paper, we are particularly concerned with the relationship between general perceptual-motor functions in relation to drawing aptitude. Drawing is by definition a perceptual-motor operation, yet mental handicap tends to be associated with some degree of impairment in this area. The following study seeks to isolate such aspects of performance on general perceptual-motor skills that might be associated with drawing ability, and may thus be regarded as building blocks underlying the manifestation of graphic talent. The results are discussed in terms of the relationships between graphic talent, non-verbal intelligence and visual-motor functions. PMID:7991749

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

    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…

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

    Petersen, Anders; Andersen, Tobias

    modelling human performance in whole and partial report tasks in which multiple simultaneously presented letters are to be reported (Shibuya & Bundesen, 1988). Therefore, we investigated visual letter identification as a function of exposure duration. On each trial, a single randomly chosen letter (A-Z) was...

  10. Visual function after penetrating keratoplasty for keratoconus: a prospective longitudinal evaluation

    Brahma, A.; Ennis, F.; Harper, R.; Ridgway, A.; Tullo, A

    2000-01-01

    AIMS—To evaluate visual function and vision specific health status in patients undergoing penetrating keratoplasty for keratoconus.
METHODS—A prospective longitudinal study measuring logMAR visual acuity, contrast sensitivity, disability glare, binocular visual field, stereoacuity, and subjective visual function (VF-14) was conducted on 18 patients with keratoconus undergoing penetrating keratoplasty (PK), including six patients who had already had PK in the fellow eye. Data were collected pr...

  11. Visual attention as an important visual function: an outline of manifestations, diagnosis and management of impaired visual attention

    Das, Meghomala; Bennett, David M.; Gordon N. Dutton

    2007-01-01

    Impaired visual attention is a common manifestation of cerebral dysfunction. In adults, closed head trauma, cerebral microvascular ischaemia and dementia are common causes. In children, aetiologies include periventricular leukomalacia, hydrocephalus, hypoxic ischaemic encephalopathy and brain damage caused by hypoglycaemia. The resultant visual disability can be profound even when visual acuities are unaffected, and can cause significant disability in the execution of daily activities. This c...

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

    Bridge, H; Thomas, OM; Minini, L.; Cavina-Pratesi, C.; Milner, AD; Parker, AJ

    2013-01-01

    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 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...

  13. Development of a Preference-Based Index from the National Eye Institute Visual Function Questionnaire-25

    Rentz, AM; Kowalski, JW; Walt, JG; Hays, RD; Brazier, JE; Yu, R; Lee, P.; BRESSLER, N.; Revicki, DA

    2014-01-01

    IMPORTANCE: Understanding how individuals value health states is central to patient-centered care and to health policy decision making. Generic preference-based measures of health may not effectively capture the impact of ocular diseases. Recently, 6 items from the National Eye Institute Visual Function Questionnaire-25 were used to develop the Visual Function Questionnaire-Utility Index health state classification, which defines visual function health states. OBJECTIVE: To describe elicitati...

  14. Functional connectivity within the visual cortex of the rat shows state changes.

    C. van der Togt; V.A.F. Lamme; H. Spekreijse

    1998-01-01

    The aim of this study was to investigate the dynamics of the horizontal functional connectivity within the visual cortex during spontaneous activity or during visual stimulation. Two arrays of 16 electrodes were inserted in the visual cortex of a rat. From these electrodes a depth profile was Obtain

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

    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.

  16. Visualization and quality assessment of the contrast transfer function estimation.

    Sheth, Lisa K; Piotrowski, Angela L; Voss, Neil R

    2015-11-01

    The contrast transfer function (CTF) describes an undesirable distortion of image data from a transmission electron microscope. Many users of full-featured processing packages are often new to electron microscopy and are unfamiliar with the CTF concept. Here we present a common graphical output to clearly demonstrate the CTF fit quality independent of estimation software. Separately, many software programs exist to estimate the four CTF parameters, but their results are difficult to compare across multiple runs and it is all but impossible to select the best parameters to use for further processing. A new measurement is presented based on the correlation falloff of the calculated CTF oscillations against the normalized oscillating signal of the data, called the CTF resolution. It was devised to provide a robust numerical quality metric of every CTF estimation for high-throughput screening of micrographs and to select the best parameters for each micrograph. These new CTF visualizations and quantitative measures will help users better assess the quality of their CTF parameters and provide a mechanism to choose the best CTF tool for their data. PMID:26080023

  17. Assessing the functions and dimensions of visualizations in foresight

    Müller, Adrian W.; Schwarz, Jan Oliver

    trend- and futures-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......Visualizations have become a vital part of many foresight activities. In the realm of creating scenarios it is stressed to visualize the different scenario as alternative pictures of the future. Corporation such as Siemens for example have developed an own approach called “pictures of the future......” to disseminate their ideas on the future of a variety of technologies. And others have made the argument that through visualizing trends in their early stage, these weak signals of change can be injected into an organization. While visualization of foresight results is considered to be very relevant...

  18. Boosting visual cortex function and plasticity with acetylcholine to enhance visual perception

    Jun-Il eKang

    2014-09-01

    Full Text Available The cholinergic system is a potent neuromodulatory system that plays critical roles in cortical plasticity, attention and learning. In this review, we propose that the cellular effects of acetylcholine in the primary visual cortex during the processing of visual inputs might induce perceptual learning; i.e., long-term changes in visual perception. Specifically, the pairing of cholinergic activation with visual stimulation increases the signal-to-noise ratio, cue detection ability and long-term facilitation in the primary visual cortex. This cholinergic enhancement would increasesthe strength of thalamocortical afferents to facilitate the treatment of a novel stimulus while decreasing the cortico-cortical signaling to reduce recurrent or top-down modulation. This balance would be mediated by different cholinergic receptor subtypes that are located on both glutamatergic and GABAergic neurons of the different cortical layers. The mechanisms of cholinergic enhancement are closely linked to attentional processes, long-term potentiation and modulation of the excitatory/inhibitory balance. Recently, it was found that boosting this system during visual training robustly enhances sensory perception in a long-term manner. Our hypothesis is that repetitive pairing of cholinergic and sensory stimulation over a long period of time induces long-term changes in the processing of trained stimuli that might improve perceptual ability. Various non-invasive approaches to the activation of the cholinergic neurons have strong potential to improve visual perception.

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

    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

  20. Detecting Visual Function Abnormality with a Contrast-Dependent Visual Test in Patients with Type 2 Diabetes.

    Tsai, Li-Ting; Liao, Kuo-Meng; Jang, Yuh; Hu, Fu-Chang; Wu, Wei-Chi

    2016-01-01

    In addition to diabetic retinopathy, diabetes also causes early retinal neurodegeneration and other eye problems, which cause various types of visual deficits. This study used a computer-based visual test (Macular Multi-Function Assessment (MMFA)) to assess contrast-dependent macular visual function in patients with type 2 diabetes to collect more visual information than possible with only the visual acuity test. Because the MMFA is a newly developed test, this study first compared the agreement and discriminative ability of the MMFA and the Early Treatment Diabetic Retinopathy Study (ETDRS) contrast acuity charts. Then symbol discrimination performances of diabetic patients and controls were evaluated at 4 contrast levels using the MMFA. Seventy-seven patients and 45 controls participated. The agreement between MMFA and ETDRS scores was examined by fitting three-level linear mixed-effect models to estimate the intraclass correlation coefficients (ICCs). The estimated areas under the receiver operating characteristic (ROC) curve were used to compare the discriminative ability of diseased versus non-diseased participants between the two tests. The MMFA scores of patients and controls were compared with multiple linear regression analysis after adjusting the effects of age, sex, hypertension and cataract. Results showed that the scores of the MMFA and ETDRS tests displayed high levels of agreement and acceptable and similar discriminative ability. The MMFA performance was correlated with the severity of diabetic retinopathy. Most of the MMFA scores differed significantly between the diabetic patients and controls. In the low contrast condition, the MMFA scores were significantly lower for 006Eon-DR patients than for controls. The potential utility of the MMFA as an easy screening tool for contrast-dependent visual function and for detecting early functional visual change in patients with type 2 diabetes is discussed. PMID:27611680

  1. On Graphic Functions of Visual FORTRAN%Visual Fortran的图形功能

    梁振光; 李际顺

    2002-01-01

    本文介绍了在Visual FORTRAN的Windows程序中实现图形显示的方法,特别是应用OpenGL实现高级三维图形操作.通过一个三维图形实例显示,Visual FORTRAN克服了以往FORTRAN语言在图形可视化方面的弱点.

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

    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 ...

  3. Visual and eye movement functions of the posterior parietal cortex

    Andersen, Richard A.

    1989-01-01

    Lesions of the posterior parietal area in humans produce interesting spatial-perceptual and spatial-behavioral deficits. Among the more important deficits observed are loss of spatial memories, problems representing spatial relations in models or drawings, disturbances in the spatial distribution of attention, and the inability to localize visual targets. Posterior parietal lesions in nonhuman primates also produce visual spatial deficits not unlike those found in humans. Mountcastle and his ...

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

    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…

  5. Visual contrast sensitivity in patients with impairment of functional independence after stroke

    dos Santos Natanael; Andrade Suellen

    2012-01-01

    Abstract Background Stroke has been considered a serious public health problem in many countries, accounting for complex disorders involving perception, such as visual, cognitive and functional deficits. The impact of stroke on the visual perception of individuals with impairments in functional independence was investigated. Methods We measured changes in functional independence and visual function in 40 patients with stroke (M = 52.3, SD = 0.65) and 10 controls (M = 52.5, SD = 0.66). The pat...

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

    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. Advancing Creative Visual Thinking with Constructive Function-Based Modelling

    Pasko, Alexander; Adzhiev, Valery; Malikova, Evgeniya; Pilyugin, Victor

    2013-01-01

    Modern education technologies are destined to reflect the realities of a modern digital age. The juxtaposition of real and synthetic (computer-generated) worlds as well as a greater emphasis on visual dimension are especially important characteristics that have to be taken into account in learning and teaching. We describe the ways in which an…

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

    Bogon, Johanna; Finke, Kathrin; Stenneken, Prisca

    2014-01-01

    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...

  9. Appearance and functionality of electronic books: lessons from the visual book and hyper-textbook projects

    Crestani, Fabio; Landoni, Monica; Melucci, Massimo

    2011-01-01

    We present the results and the lessons learned from two separate and independent studies into the design, development, and evaluation of electronic books for information access: the Visual Book and the Hyper-TextBook. The Visual Book explored the importance of the visual component of the book metaphor in the production of “good” electronic books for referencing. The Hyper-TextBook concentrated on the importance of models and techniques for the automatic production of functional electronic ...

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

    Marissa Romano da Silva; Maria Inês Rubo de Souza Nobre; Keila Monteiro de Carvalho; Rita de Cássia Ietto Montilha

    2014-01-01

    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 occupationa...

  11. Neural correlates of perceptual learning: A functional MRI study of visual texture discrimination

    Schwartz, Sophie; Maquet, Pierre; Frith, Chris

    2002-01-01

    Visual texture discrimination has been shown to induce long-lasting behavioral improvement restricted to the trained eye and trained location in visual field [Karni, A. & Sagi, D. (1991) Proc. Natl. Acad. Sci. USA 88, 4966–4970]. We tested the hypothesis that such learning involves durable neural modifications at the earliest cortical stages of the visual system, where eye specificity, orientation, and location information are mapped with highest resolution. Using functional magnetic resonanc...

  12. Tracking the evolution of crossmodal plasticity and visual functions before and after sight restoration

    Dormal, Giulia; Lepore, Franco; Harissi-Dagher, Mona; Albouy, Geneviève; Bertone, Armando; Rossion, Bruno; COLLIGNON, olivier

    2014-01-01

    Visual deprivation leads to massive reorganization in both the structure and function of the occipital cortex, raising crucial challenges for sight restoration. We tracked the behavioral, structural, and neurofunctional changes occurring in an early and severely visually impaired patient before and 1.5 and 7 mo after sight restoration with magnetic resonance imaging. Robust presurgical auditory responses were found in occipital cortex despite residual preoperative vision. In primary visual co...

  13. Comparative visual function in four piscivorous fishes inhabiting Chesapeake Bay.

    Horodysky, Andrij Z; Brill, Richard W; Warrant, Eric J; Musick, John A; Latour, Robert J

    2010-05-01

    Maintaining optimal visual performance is a difficult task in photodynamic coastal and estuarine waters because of the unavoidable tradeoffs between luminous sensitivity and spatial and temporal resolution, yet the visual systems of coastal piscivores remain understudied despite differences in their ecomorphology and microhabitat use. We therefore used electroretinographic techniques to describe the light sensitivities, temporal properties and spectral sensitivities of the visual systems of four piscivorous fishes common to coastal and estuarine waters of the western North Atlantic: striped bass (Morone saxatilis), bluefish (Pomatomus saltatrix), summer flounder (Paralichthys dentatus) and cobia (Rachycentron canadum). Benthic summer flounder exhibited higher luminous sensitivity and broader dynamic range than the three pelagic foragers. The former were at the more sensitive end of an emerging continuum for coastal fishes. By contrast, pelagic species were comparatively less sensitive, but showed larger day-night differences, consistent with their use of diel light-variant photic habitats. Flicker fusion frequency experiments revealed significant interspecific differences at maximum intensities that correlated with lifestyle and habitat. Spectral responses of most species spanned 400-610 nm, with significant day-night differences in striped bass and bluefish. Anadromous striped bass additionally responded to longer wavelengths, similar to many freshwater fishes. Collectively, these results suggest that pelagic piscivores are well adapted to bright photoclimates, which may be at odds with the modern state of eutrified coastal and estuarine waters that they utilize. Recent anthropogenic degradation of water quality in coastal environments, at a pace faster than the evolution of visual systems, may impede visually foraging piscivores, change selected prey, and eventually restructure ecosystems. PMID:20435826

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

    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

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

    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

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

    Born, Alfred Peter; Leth, H; Miranda Gimenez-Ricco, Maria Jo; Rostrup, Egill; Stensgaard, A; Peitersen, Birgit; Larsson, H B; Lou, H C

    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...

  17. Functional segregation and temporal hierarchy of the visual perceptive systems.

    Moutoussis, K.; Zeki, S

    1997-01-01

    In extending our previous work, we addressed the question of whether different visual attributes are perceived separately when they belong to different objects, rather than the same one. Using our earlier psychophysical method, but separating the attributes to be paired in two different halves of the screen, we found that human subjects misbind the colour and the direction of motion, or the colour and the orientation of lines, because colour, form, and motion are perceived separately and at d...

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

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

    2000-09-01

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

  19. 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

    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)

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

    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. PMID:27143090

  1. Investigations of the human visual system using functional magnetic resonance imaging (FMRI)

    The application of functional magnetic resonance imaging (fMRI) in studies of the visual system provided significant advancement in our understanding of the organization and functional properties of visual areas in the human cortex. Recent technological and methodological improvements allowed studies to correlate neuronal activity with visual perception and demonstrated the ability of fMRI to observe distributed neural systems and to explore modulation of neural activity during higher cognitive processes. Preliminary applications in patients with visual impairments suggest that this method provides a powerful tool for the assessment and management of brain pathologies. Recent research focuses on obtaining new information about the spatial localization, organization, functional specialization and participation in higher cognitive functions of visual cortical areas in the living human brain and in further establishment of the method as a useful clinical tool of diagnostic and prognostic significance for various pathologic processes affecting the integrity of the visual system. It is anticipated that the combined neuroimaging approach in patients with lesions and healthy controls will provide new insight on the topography and functional specialization of cortical visual areas and will further establish the clinical value of the method for improving diagnostic accuracy and treatment planning

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

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

    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 a...

  3. Visual imagery and functional connectivity in blindness: a single-case study

    Boucard, Christine C.; Rauschecker, Josef P.; Neufang, Susanne; Berthele, Achim; Doll, Anselm; Manoliu, Andrej; Riedl, Valentin; Sorg, Christian; Wohlschläger, Afra; Mühlau, Mark

    2016-01-01

    We present a case report on visual brain plasticity after total blindness acquired in adulthood. SH lost her sight when she was 27. Despite having been totally blind for 43 years, she reported to strongly rely on her vivid visual imagery. Three-Tesla magnetic resonance imaging (MRI) of SH and age-matched controls was performed. The MRI sequence included anatomical MRI, resting-state functional MRI, and task-related functional MRI where SH was instructed to imagine colours, faces, and motion. Compared to controls, voxel-based analysis revealed white matter loss along SH's visual pathway as well as grey matter atrophy in the calcarine sulci. Yet we demonstrated activation in visual areas, including V1, using functional MRI. Of the four identified visual resting-state networks, none showed alterations in spatial extent; hence, SH's preserved visual imagery seems to be mediated by intrinsic brain networks of normal extent. Time courses of two of these networks showed increased correlation with that of the inferior posterior default mode network, which may reflect adaptive changes supporting SH's strong internal visual representations. Overall, our findings demonstrate that conscious visual experience is possible even after years of absence of extrinsic input. PMID:25690326

  4. Visual imagery and functional connectivity in blindness: a single-case study.

    Boucard, Christine C; Rauschecker, Josef P; Neufang, Susanne; Berthele, Achim; Doll, Anselm; Manoliu, Andrej; Riedl, Valentin; Sorg, Christian; Wohlschläger, Afra; Mühlau, Mark

    2016-05-01

    We present a case report on visual brain plasticity after total blindness acquired in adulthood. SH lost her sight when she was 27. Despite having been totally blind for 43 years, she reported to strongly rely on her vivid visual imagery. Three-Tesla magnetic resonance imaging (MRI) of SH and age-matched controls was performed. The MRI sequence included anatomical MRI, resting-state functional MRI, and task-related functional MRI where SH was instructed to imagine colours, faces, and motion. Compared to controls, voxel-based analysis revealed white matter loss along SH's visual pathway as well as grey matter atrophy in the calcarine sulci. Yet we demonstrated activation in visual areas, including V1, using functional MRI. Of the four identified visual resting-state networks, none showed alterations in spatial extent; hence, SH's preserved visual imagery seems to be mediated by intrinsic brain networks of normal extent. Time courses of two of these networks showed increased correlation with that of the inferior posterior default mode network, which may reflect adaptive changes supporting SH's strong internal visual representations. Overall, our findings demonstrate that conscious visual experience is possible even after years of absence of extrinsic input. PMID:25690326

  5. Functional Neuroimaging to Characterize Visual System Development in Children with Retinoblastoma

    Barb, Scott M.; Rodriguez-Galindo, Carlos; Matthew W Wilson; Phillips, Nicholas S.; Zou, Ping; Scoggins, Matthew A.; Li, Yimei; Qaddoumi, Ibrahim; Helton, Kathleen J.; Bikhazi, George; Haik, Barrett G.; Ogg, Robert J.

    2011-01-01

    Functional MRI and diffusion tensor imaging in children being treated for retinoblastoma showed that patterns of visual activation and diffusion parameters in associated white matter pathways reflected neural changes caused by disease and treatment.

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

    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.

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

    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. PMID:26441748

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

    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.

  9. Tracking the evolution of crossmodal plasticity and visual functions before and after sight restoration.

    Dormal, Giulia; Lepore, Franco; Harissi-Dagher, Mona; Albouy, Geneviève; Bertone, Armando; Rossion, Bruno; Collignon, Olivier

    2015-03-15

    Visual deprivation leads to massive reorganization in both the structure and function of the occipital cortex, raising crucial challenges for sight restoration. We tracked the behavioral, structural, and neurofunctional changes occurring in an early and severely visually impaired patient before and 1.5 and 7 mo after sight restoration with magnetic resonance imaging. Robust presurgical auditory responses were found in occipital cortex despite residual preoperative vision. In primary visual cortex, crossmodal auditory responses overlapped with visual responses and remained elevated even 7 mo after surgery. However, these crossmodal responses decreased in extrastriate occipital regions after surgery, together with improved behavioral vision and with increases in both gray matter density and neural activation in low-level visual regions. Selective responses in high-level visual regions involved in motion and face processing were observable even before surgery and did not evolve after surgery. Taken together, these findings demonstrate that structural and functional reorganization of occipital regions are present in an individual with a long-standing history of severe visual impairment and that such reorganizations can be partially reversed by visual restoration in adulthood. PMID:25520432

  10. Experiences with Matlab and VRML in Functional Neuroimaging Visualizations

    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.

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

    Born, A.P.; Miranda Gimenez-Ricco, Maria Jo; Rostrup, Egill; Toft, P.B.; Peitersen, Birgit; Larsson, H.B.; Lou, H.C.

    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...... children 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......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...

  12. Experiences with Matlab and VRML in Functional Neuroimaging Visualizations

    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.......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....

  13. VIZ-GRAIL: visualizing functional connections across disease loci

    Raychaudhuri, Soumya

    2011-01-01

    Motivation: As disease loci are rapidly discovered, an emerging challenge is to identify common pathways and biological functionality across loci. Such pathways might point to potential disease mechanisms. One strategy is to look for functionally related or interacting genes across genetic loci. Previously, we defined a statistical strategy, Gene Relationships Across Implicated Loci (GRAIL), to identify whether pair-wise gene relationships defined using PubMed text similarity are enriched acr...

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

    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.

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

    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. PMID:26344580

  16. How You Use It Matters: Object Function Guides Attention During Visual Search in Scenes.

    Castelhano, Monica S; Witherspoon, Richelle L

    2016-05-01

    How does one know where to look for objects in scenes? Objects are seen in context daily, but also used for specific purposes. Here, we examined whether an object's function can guide attention during visual search in scenes. In Experiment 1, participants studied either the function (function group) or features (feature group) of a set of invented objects. In a subsequent search, the function group located studied objects faster than novel (unstudied) objects, whereas the feature group did not. In Experiment 2, invented objects were positioned in locations that were either congruent or incongruent with the objects' functions. Search for studied objects was faster for function-congruent locations and hampered for function-incongruent locations, relative to search for novel objects. These findings demonstrate that knowledge of object function can guide attention in scenes, and they have important implications for theories of visual cognition, cognitive neuroscience, and developmental and ecological psychology. PMID:27022016

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

    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. Learning to See: Patterned visual activity and the development of visual function

    Ruthazer, Edward S; Aizenman, Carlos D.

    2010-01-01

    To successfully interact with their environment, developing organisms need to correctly process sensory information and generate motor output appropriate to their size and structure. Patterned sensory experience has long been known to induce various forms of developmental plasticity which ultimately shape mature neural circuits. Yet these same types of plasticity also allow developing organisms to respond appropriately to the external world by dynamically adapting neural circuit function to o...

  19. Functions of Interactive Visual Representations in Interactive Mathematical Textbooks

    Yerushalmy, Michal

    2005-01-01

    The paper explores changes in technology that have implications for the teaching and learning of school mathematics. To this end, it examines aspects of interactive mathematical textbooks; specifically it analyzes functions authors may intend to be carried out by embedded interactive diagrams. The paper analyzes theoretical as well as practical…

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

    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.

  1. Spatial and attentional functions of the midbrain visual system

    Foreman, Nigel

    1980-01-01

    The superior colliculus of the midbrain has been implicated in spatial and attentional behaviours, in particular the redirecting of attention to novel peripheral stimuli. Paradoxically, while certain aspects of sensory and motor organisation within the structure are common to all species studied, others (eg. single unit characteristics) show wide interspecies variation. Models of intracollicular processing and possible functional subdivisions were discussed. The hippocampal formation and ...

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

    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.

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

    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.

  4. The Association between Resting Functional Connectivity and Visual Creativity

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

    2016-01-01

    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. PMID:27138732

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

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

    2016-01-01

    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. PMID:27138732

  6. Functional images analysis and visualization in positron emission tomography

    Essentially new information on the metabolism and pathophysiology is available since the recent past using techniques combining the use of positron emitters labelling radiopharmaceuticals, models correctly describing the process studied and system for the in vivo external detection of transverse section of the body. This method is currently called Positron Emission Tomography (PET). At the Service Hospitalier Frederic Joliot of the C.E.A. Departement of Biology, a system was developed for data analysis and colour-coded representation as a tool for functional interpretation. Indeed, the tomographic images, i.e. the radioactive concentration in the transverse section is often but the first step of the study, the actual goal being the regional distribution of a metabolic or physiologic parameter, itself derived from the former distribution by assumption of a model. Such a quantification assumes an accurate analysis of the factors involved in the obtention of the functional image, and the development of the software actually adapted to the clinician's needs. Special attention was given to the representation of graphs and images as a man-machine interface, a tool for model fitting and output of final results in pseudo-color scales adapted to the studied parameter

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

    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.

  8. Exploratory Analysis of Biological Networks through Visualization, Clustering, and Functional Annotation in Cytoscape.

    Baryshnikova, Anastasia

    2016-01-01

    Biological networks define how genes, proteins, and other cellular components interact with one another to carry out specific functions, providing a scaffold for understanding cellular organization. Although in-depth network analysis requires advanced mathematical and computational knowledge, a preliminary visual exploration of biological networks is accessible to anyone with basic computer skills. Visualization of biological networks is used primarily to examine network topology, identify functional modules, and predict gene functions based on gene connectivity within the network. Networks are excellent at providing a bird's-eye view of data sets and have the power of illustrating complex ideas in simple and intuitive terms. In addition, they enable exploratory analysis and generation of new hypotheses, which can then be tested using rigorous statistical and experimental tools. This protocol describes a simple procedure for visualizing a biological network using the genetic interaction similarity network for Saccharomyces cerevisiae as an example. The visualization procedure described here relies on the open-source network visualization software Cytoscape and includes detailed instructions on formatting and loading the data, clustering networks, and overlaying functional annotations. PMID:26988373

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

    Heine, Lizette; Bahri, Mohamed A; Cavaliere, Carlo; Soddu, Andrea; Laureys, Steven; Ptito, Maurice; Kupers, Ron

    2015-01-01

    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 congenital 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 reorganization in the brain and the supra-modal function of the occipital cortex in congenitally blind individuals. PMID:26190978

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

    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

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

    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.

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

    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.

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

    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

  14. Visual function after strontium-90 plaque irradiation in patients with age-related subfoveal choroidal neovascularization

    Purpose: To report 2-year visual and angiographic results in eyes treated with strontium plaque irradiation for subfoveal choroidal neovascular membranes (CNVM) in age-related macular degeneration. Methods: Twenty eyes with recent subfoveal CNVM were treated with local irradiation. The impact of the treatment on visual function was evaluated by visual acuity, contrast sensitivity and reading speed testing. Results: At 12 months visual acuity had improved or remained the same in 9/20 eyes (45%). At 24 months visual acuity was stable in 5/18 eyes (28%). Eyes with signs of CNVM regression (13/18,72%) lost a mean of 3.3 lines, but eyes with recurrent CNVM lost a mean of 5.1 lines of vision. The mean contrast sensitivity was better in the irradiated eyes than in the fellow eyes with late age-related macular degeneration at 24 months. Six of 17 irradiated eyes (35%) could read at least some words at 24 months. Conclusion: Visual function decreases in patients treated with strontium irradiation, but less in eyes showing regression of the CNVM than in eyes with further growth of the CNVM. (au)

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

    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.

  16. Efficiency of initial presbyopia functional correction in visually intensive work persons

    I. G. Ovechkin

    2014-01-01

    Full Text Available Aim: To study the efficacy of functional (physiotherapeutic stimulation of an eye in visually intensive work patients with the initial symptoms of presbyopia.Methods: 104 visually intensive work patients before and after complex physiotherapy (low-energy laser radiation, magnitotherapy, stimulation of accommodation were examined.Results: Physiotherapy improved near vision (by 0.16 RU on average and subjective psychophysiological status (by 11.8 % and reduced eye strain (by 2.1 times. Additionally, objective accommodography indices improved, brightness sensitivity thresholds decreased by 16.5 %, and psychological status improved by 18.2 %. These positive effects of physiotherapeutic stimulation enabled to delay eyeglasses prescription for 6 months in 76 % of patients and for 9 months in 42 % of patients.Conclusion: Functional (physiotherapeutic stimulation provides effective correction of initial presbyopia in visually intensive work persons.

  17. Efficiency of initial presbyopia functional correction in visually intensive work persons

    I. G. Ovechkin

    2015-01-01

    Full Text Available Aim: To study the efficacy of functional (physiotherapeutic stimulation of an eye in visually intensive work patients with the initial symptoms of presbyopia.Methods: 104 visually intensive work patients before and after complex physiotherapy (low-energy laser radiation, magnitotherapy, stimulation of accommodation were examined.Results: Physiotherapy improved near vision (by 0.16 RU on average and subjective psychophysiological status (by 11.8 % and reduced eye strain (by 2.1 times. Additionally, objective accommodography indices improved, brightness sensitivity thresholds decreased by 16.5 %, and psychological status improved by 18.2 %. These positive effects of physiotherapeutic stimulation enabled to delay eyeglasses prescription for 6 months in 76 % of patients and for 9 months in 42 % of patients.Conclusion: Functional (physiotherapeutic stimulation provides effective correction of initial presbyopia in visually intensive work persons.

  18. Learning one-to-many mapping functions for audio-visual integrated perception

    Lim, Jung-Hui; Oh, Do-Kwan; Lee, Soo-Young

    2010-04-01

    In noisy environment the human speech perception utilizes visual lip-reading as well as audio phonetic classification. This audio-visual integration may be done by combining the two sensory features at the early stage. Also, the top-down attention may integrate the two modalities. For the sensory feature fusion we introduce mapping functions between the audio and visual manifolds. Especially, we present an algorithm to provide one-to-many mapping function for the videoto- audio mapping. The top-down attention is also presented to integrate both the sensory features and classification results of both modalities, which is able to explain McGurk effect. Each classifier is separately implemented by the Hidden-Markov Model (HMM), but the two classifiers are combined at the top level and interact by the top-down attention.

  19. SIMPLE EXPONENTIAL FUNCTIONS DESCRIBING THE ABSORBENCY BANDS OF VISUAL PIGMENT SPECTRA

    STAVENGA, DG; SMITS, RP; HOENDERS, BJ

    1993-01-01

    Literature data for visual pigment spectra are formally treated by assuming that the spectra consist of a summation of absorbance bands, that the shape of the bands is invariant according to the Mansfield-MacNichol transform and that this shape is described by simple exponential functions. A new tem

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

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

    2015-01-01

    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......-modal reorganization in the brain and the supra-modal function of the occipital cortex in congenitally blind individuals....

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

    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

  2. Visualization of usability and functionality of a professional website through web-mining.

    Jones, Josette F; Mahoui, Malika; Gopa, Venkata Devi Pragna

    2007-01-01

    Functional interface design requires understanding of the information system structure and the user. Web logs record user interactions with the interface, and thus provide some insight into user search behavior and efficiency of the search process. The present study uses a data-mining approach with techniques such as association rules, clustering and classification, to visualize the usability and functionality of a digital library through in depth analyses of web logs. PMID:18694096

  3. Visualizing digestive organ morphology and function using differential fatty acid metabolism in live zebrafish

    Carten, Juliana Debrito; Bradford, Mary Katherine; Farber, Steven Arthur

    2011-01-01

    Lipids are essential for cellular function as sources of fuel, critical signaling molecules and membrane components. Deficiencies in lipid processing and transport underlie many metabolic diseases. To better understand metabolic function as it relates to disease etiology, a whole animal approach is advantageous, one in which multiple organs and cell types can be assessed simultaneously in vivo. Towards this end, we have developed an assay to visualize fatty acid (FA) metabolism in larval zebr...

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

    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

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

    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.

  6. SonicFunction: Experiments with a function browser for the visually impaired

    Grond, Florian; Drossard, Trixi; Hermann, Thomas; Brazil, Eoin

    2010-01-01

    We present in this paper SonicFunction, a prototype for the interactive sonification of mathematical functions. Since many approaches to represent mathematical functions as auditory graphs exist already, we introduce in SonicFunction three new aspects related to sound design. Firstly, SonicFunction features a hybrid approach of discrete and continuous sonification of the function values f(x). Secondly, the sonification includes information about the derivative of the function. Thirdly, Soni...

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

    Rovniy A.S.; Buren N.V.

    2010-01-01

    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 educa...

  8. Efficiency of initial presbyopia functional correction in visually intensive work persons

    I. G. Ovechkin; N. N. Agafonov; V. E. Judin

    2015-01-01

    Aim: To study the efficacy of functional (physiotherapeutic) stimulation of an eye in visually intensive work patients with the initial symptoms of presbyopia.Methods: 104 visually intensive work patients before and after complex physiotherapy (low-energy laser radiation, magnitotherapy, stimulation of accommodation) were examined.Results: Physiotherapy improved near vision (by 0.16 RU on average) and subjective psychophysiological status (by 11.8 %) and reduced eye strain (by 2.1 times). Add...

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

    Xin Di

    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.

  10. In Search of a Visual-cortical Describing Function: a Summary of Work in Progress

    Junker, A. M.; Peio, K. J.

    1984-01-01

    The thrust of the present work is to explore the utility of using a sum of sinusoids (seven or more) to obtain an evoked response and, furthermore, to see if the response is sensitive to changes in cognitive processing. Within the field of automatic control system technology, a mathematical input/output relationship for a sinusoidally stimulated nonlinear system is defined as describing function. Applying this technology, sum of sines inputs to yield describing functions for the visual-cortical response have been designed. What follows is a description of the method used to obtain visual-cortical describing functions. A number of measurement system redesigns were necessary to achieve the desired frequency resolution. Results that guided and came out of the redesigns are presented. Preliminary results of stimulus parameter effects (average intensity and depth of modulation) are also shown.

  11. Preserved local but disrupted contextual figure-ground influences in an individual with abnormal function of intermediate visual areas

    Brooks, Joseph L.; Gilaie-Dotan, Sharon; Rees, Geraint; Bentin, Shlomo; Driver, Jon

    2012-01-01

    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 intermedi...

  12. Structural dynamics of synapses in vivo correlate with functional changes during experience-dependent plasticity in visual cortex

    Tropea, Daniela; Majewska, Ania K.; Garcia, Rodrigo; Sur, Mriganka

    2010-01-01

    The impact of activity on neuronal circuitry is complex, involving both functional and structural changes whose interaction is largely unknown. We have used optical imaging of mouse visual cortex responses and two-photon imaging of superficial layer spines on layer 5 neurons to monitor network function and synaptic structural dynamics in the mouse visual cortex in vivo. Total lack of vision due to dark-rearing from birth dampens visual responses and shifts spine dynamics and morphologies towa...

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

    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...

  14. Globe preservation and visual function after endoresection and Gamma-Knife radiosurgery for uveal melanomas

    Eyes with uveal melanoma sometimes need surgical intervention cause of radiation induced retinal complications. We report visual outcome, complications and globe preservation rates. 13 patients (10 male, 3 female) with a mean age of 64 years (range 42-88 years) were treated by single fraction Gamma Knife radiosurgery in 12 patients, two had previous thermotherapy and in one patient Ruthenium 106 brachytherapy was administered. All were subsequently endoresected by pars plana vitrectomy and silicone oil tamponade. In six patients period was less than six months (median, 2 months) and in seven patients period was more than six months (median, 19 months). Mean tumor base was 12.5 mm (range 8.3-20 mm), mean tumor prominence 9 mm (4.4-16.5 mm). Visual acuity was LP-20/400 in five, 20/200-20/40 in seven and 20/20 in one patient before radiation. Globe preservation was achieved in 12/13 (92 %), in 13/13 total tumor regression without any recurrence was achieved. Visual acuity after surgery was NLP in five patients, in seven patients LP-20/400 and in one patient 20/200. No clinically significant difference in visual acuity was seen in the group with endoresection earlier or later than six months. Seven additional operations after primary vitreoretinal surgery had to be performed (four vitrectomies, one enucleation and one lavage of the anterior chamber). Two patients developed distant metastases. Our data show that combined vitreoretinal surgery and endoresection after radiation are an acceptable management option for preservation of the globe and the residual visual function in uveal melanomas with retinal detachment or vitreous bleeding, yet visual function is determined by radiation induced side effects and the duration of the retinal detachment. (author)

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

    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.

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

    Bogon, Johanna; Finke, Kathrin; Stenneken, Prisca

    2014-01-01

    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" (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 suggests that having limited reading and writing skills might impair the development of a slight leftward bias, that is typical for unimpaired adult readers. PMID:25360129

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

    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.

  18. Early-onset bipolar disorder: how about visual-spatial skills and executive functions?

    Lera-Miguel, Sara; Andrés-Perpiñá, Susana; Calvo, Rosa; Fatjó-Vilas, Mar; Fañanás, Lourdes; Lourdes, Fañanás; Lázaro, Luisa

    2011-04-01

    Early-onset bipolar disorder is an impairing condition that is strongly associated with genetic inheritance. Neurocognitive deficits are core traits of this disorder which seem to be present in both young and adult forms. Deficits in verbal memory and attention are persistent within euthymic phases in bipolar adults, adolescents, and children. In younger samples, including type I or II and not otherwise specified patients, executive functions are not widely impaired and the existence of visual-spatial deficits remains unclear. The main aim of this study was to compare the neurocognitive performance in young stabilized type I or II bipolar patients and healthy controls. Fifteen medicated adolescents with bipolar disorder and 15 healthy adolescents, matched in age and gender, were compared on visual-spatial skills (reasoning, memory, visual-motor accuracy) and executive functioning (attention and working memory, set-shifting, inhibition) using t-tests and MANCOVA. Correcting for verbal competence, MANCOVA showed that patients performed significantly worse than controls in letters and numbers sequencing (P = 0.003), copy (P Test, interference of the Stroop Color-Word Test (P = 0.007) and non-perseverative errors on the Wisconsin Card Sorting Test (P = 0.038). Impaired cognitive performance was found in young bipolar patients in working memory, visual-motor skills, and inhibitory control. PMID:21086134

  19. Does Congenital Deafness Affect the Structural and Functional Architecture of Primary Visual Cortex?

    Smittenaar, C R; MacSweeney, M; Sereno, M I; Schwarzkopf, D S

    2016-01-01

    Deafness results in greater reliance on the remaining senses. It is unknown whether the cortical architecture of the intact senses is optimized to compensate for lost input. Here we performed widefield population receptive field (pRF) mapping of primary visual cortex (V1) with functional magnetic resonance imaging (fMRI) in hearing and congenitally deaf participants, all of whom had learnt sign language after the age of 10 years. We found larger pRFs encoding the peripheral visual field of deaf compared to hearing participants. This was likely driven by larger facilitatory center zones of the pRF profile concentrated in the near and far periphery in the deaf group. pRF density was comparable between groups, indicating pRFs overlapped more in the deaf group. This could suggest that a coarse coding strategy underlies enhanced peripheral visual skills in deaf people. Cortical thickness was also decreased in V1 in the deaf group. These findings suggest deafness causes structural and functional plasticity at the earliest stages of visual cortex. PMID:27014392

  20. Research progress of functional magnetic resonance imaging in cross-modal activation of visual cortex during tactile perception

    An increasing amount of neuroimaging studies recently demonstrated activation of visual cortex in both blind and sighted participants when performing a variety of tactile tasks such as Braille reading and tactile object recognition, which indicates that visual cortex not only receives visual information, but may participate in tactile perception. To address these cross-modal changes of visual cortex and the neurophysiological mechanisms, many researchers conducted explosive studies using functional magnetic resonance imaging (fMRI) and have made some achievements. This review focuses on cross-modal activation of visual cortex and the underlying mechanisms during tactile perception in both blind and sighted individuals. (authors)

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

    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.

  2. Improving visual functions in adult amblyopia with combined perceptual training and transcranial random noise stimulation (tRNS): a pilot study

    Campana, Gianluca; Camilleri, Rebecca; Pavan, Andrea; Veronese, Antonella; Lo Giudice, Giuseppe

    2014-01-01

    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 i...

  3. [Reinnervation of central visual areas and recovery of visual functions following optic nerve regeneration in adult mice].

    Koriyama, Yoshiki; Kurimoto, Takuji; de Lima, Silmara; Benowitz, Larry

    2014-03-01

    The optic nerve has been widely studied in search for insights into mechanisms that suppress or promote axon regeneration after injury. Like other CNS neurons, adult retinal ganglion cells (RGCs) normally fail to regenerate their axons after optic nerve injury. Recent studies have identified molecular pathways able to allow partial regeneration of damaged RGCs axons in mature rodents; however, it is still unknown, whether regrowing optic axons can re-enter the brain in large numbers, innervate the correct target areas, and thus restore vision. We investigated these questions by using three manipulations that synergistically increase regeneration far above the level induced by any of the three used alone. Oncomodulin is a calcium-binding protein secreted by activated macrophages and neutrophils and stimulates RGCs to regenerate axons. Its ability to bind to RGCs and activate a downstream response is enhanced by elevating intracellular cAMP. Studies were carried out in mice with a conditional deletion of the gene encoding PTEN, a phosphatase and tensin homolog that suppresses signaling through the Akt/mTOR/S6K pathway. Our results showed that intraocular inflammation, deletion of the PTEN gene and elevation of intracellular cAMP exert synergistic effects that enable RGCs to regenerate the full length of axons, form synapses, and restore simple visual functions. These results demonstrate the feasibility of reconstructing central circuitry for vision after optic nerve damage in mature mammals. PMID:24607951

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

    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...... flow during activation. The different response patterns in young children and adults can reflect developmental or behavioral differences. Localization of the activation seemed to be age-dependent. In the older children and the adults, it encompassed the whole length of the calcarine sulcus, whereas it...

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

    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.

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

    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.

  7. Visual Hierarchical Processing and Lateralization of Cognitive Functions through Domestic Chicks' Eyes

    Chiandetti, Cinzia; Pecchia, Tommaso; Patt, Francesco; Vallortigara, Giorgio

    2014-01-01

    Hierarchical stimuli have proven effective for investigating principles of visual organization in humans. A large body of evidence suggests that the analysis of the global forms precedes the analysis of the local forms in our species. Studies on lateralization also indicate that analytic and holistic encoding strategies are separated between the two hemispheres of the brain. This raises the question of whether precedence effects may reflect the activation of lateralized functions within the b...

  8. Relationship between Functional Visual Acuity and Useful Field of View in Elderly Drivers.

    Kazuno Negishi

    Full Text Available To investigate the relationship between the functional visual acuity (FVA and useful field of view (UFOV in elderly drivers and assess the usefulness of the FVA test to screen driving aptitude in elderly drivers.This study included 45 elderly drivers (31 men, 14 women; mean age, 68.1 years and 30 younger drivers (26 men, 4 women; mean age, 34.2 years who drive regularly. All participants underwent measurement of the binocular corrected distant visual acuity (CDVA, binocular corrected distant FVA (CDFVA, and Visual Field with Inhibitory Tasks Elderly Version (VFIT-EV to measure UFOV. The tear function and cognitive status also were evaluated.The CDVA, the CDFVA, cognitive status, and the correct response rate (CAR of the VFIT-EV were significantly worse in the elderly group than in the control group (P = 0.000 for all parameters. The cognitive status was correlated significantly with the CDVA (r = -0.301, P = 0.009, CDFVA (r = -0.402, P = 0.000, and the CAR of the VFIT-EV (r = 0.348, P = 0.002 in all subjects. The results of the tear function tests were not correlated with the CDVA, CDFVA, or VFIT-EV in any subjects. Stepwise regression analysis for all subjects in the elderly and control groups showed that the CDFVA predicted the CAR most significantly among the clinical factors evaluated.The FVA test is a promising method to screen the driving aptitude, including both visual and cognitive functions, in a short time.

  9. Changes in protein synthesis underlying functional plasticity in immature monkey visual system.

    Kennedy, C; Suda, S; Smith, C. B.; Miyaoka, M; Ito, M.; Sokoloff, L

    1981-01-01

    Local rates of cerebral protein synthesis were determined in newborn rhesus monkeys subjected to either acute or chronic monocular visual deprivation. Chronic monocular deprivation resulted in decreased rates of protein synthesis in the laminae of the lateral geniculate nuclei innervated by the deprived eye whereas rates of protein synthesis were normal in geniculate laminae innervated by the functioning eye. Acute monocular deprivation produced no differential changes in rates of protein syn...

  10. Functional Lateralization of Temporoparietal Junction: Imitation Inhibition, Visual Perspective Taking and Theory of Mind.

    Santiesteban, I; Banissy, MJ; Catmur, C.; Bird, G

    2015-01-01

    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, bilateral TPJ activation is found during theory of mind tasks 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 theor...

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

    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

  12. Functional interaction between the dorsal hippocampus and the striatum in visual discrimination learning.

    Fidalgo, C; Conejo, N M; González-Pardo, H; Arias, J L

    2012-03-01

    The hippocampus and the striatum have traditionally been considered as part of different and independent memory systems. However, there is evidence that supports a functional interaction between the hippocampus and the dorsal striatum at least in particular learning tasks. Here, we evaluated the functional contribution of both brain regions in a visual discrimination learning task using cytochrome c oxidase (CO) quantitative histochemistry. Compared with other brain metabolic mapping techniques, CO activity reflects steady-state neuronal energy demand. Rats were trained for 6 days in a water T-maze to find a hidden escape platform associated with an intramaze visual cue. A control group of animals swam for an equivalent amount of time compared as the trained group but without any escape platform available. After finishing the behavioral task, CO activity was measured in subdivisions of the dorsal hippocampus and the dorsal striatum in both groups. Results show significantly higher CO activity in the CA1 area and the dentate gyrus of the dorsal hippocampus in the trained rats compared with the control group. In addition, a significant negative functional cross-correlation between area CA1 of the dorsal hippocampus and the anterodorsal striatum was found. Our results support current theories on competitive interaction of different memory systems during visual discrimination learning. PMID:22012685

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

    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. PMID:25704454

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

    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.

  15. Stimulus and optode placement effects on functional near-infrared spectroscopy of visual cortex.

    Kashou, Nasser H; Giacherio, Brenna M

    2016-04-01

    Functional near-infrared spectroscopy has yet to be implemented as a stand-alone technique within an ophthalmology clinical setting, despite its promising advantages. The present study aims to further investigate reliability of visual cortical signals. This was achieved by: (1) assessing the effects of optode placements using the 10-20 International System of Electrode Placement consisting of 28 channels, (2) determining effects of stimulus size on response, and (3) evaluating response variability as a result of cap placement across three sessions. Ten participants with mean age [Formula: see text] years (five male) and varying types of hair color and thickness were recruited. Visual stimuli of black-and-white checkerboards, reversing at a frequency of 7.5 Hz were presented. Visual angles of individual checker squares included 1 deg, 2 deg, 5 deg, 9 deg, and 18 deg. The number of channels that showed response was analyzed for each participant, stimulus size, and session. 1-deg stimulus showed the greatest activation. One of three data collection sessions for each participant gave different results ([Formula: see text]). Hair color and thickness each had an effect upon the overall HbO ([Formula: see text]), while only color had a significant effect for HbD ([Formula: see text]). A reliable level of robustness and consistency is still required for clinical implementation and assessment of visual dysfunction. PMID:27335887

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

    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.

  17. Study of the perception of visual motion in amblyopia using functional MRI

    Objective: To research the pathophysiological mechanism of anisometropic and strabismic amblyopia through observation of the cortex activation under the stimulus of visual motion using functional MRI (fMRI). Methods: Seven patients with anisometropic amblyopia and 10 patients with strabismic amblyopia were examined under the stimulus with the paradigm that task and control states were rotating and stationary grating with 1.5 T MR scanners. The data were processed using software of SPM offline, and the result was analyzed with single subject. An index of interocular difference of activation (IDA) was set for Mann-Whitney rank sum test to denote the extension of difference between activation of each eye. Results: There appeared activation on bilaterally occipital lobe in both group of amblyopia patients. There was mild activation on frontal lobe when amblyopic eyes were stimulated, but no activation when sound eyes. The MT area was regarded as region of interesting when analyzed, the activation of all sound eyes was stronger than amblyopic eyes in 7 anisometropic amblyopia patients. There were 5 patients whose level of activation of amblyopic eye's were lower than sound eye, and four were higher than sound eye, among the strabismic amblyopia patients except one patient's activation was none. There was statistical difference between IDA value of two groups (Z=2.382, P=0.017). Conclusion: There are more cortex areas activated of amblyopic eye than sound eye when single eye is stimulated. The function of visual motion maybe has been affected in anisometropic amblyopia. In strabismic amblyopia, the function of visual motion may relate to the underlying mechanism of strabismic, which suggests, as for the impairment of perception of visual motion, there is difference between two types of amblyopia. (authors)

  18. Exploration of high-dimensional scalar function for nuclear reactor safety analysis and visualization

    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 data from a nuclear reactor safety simulation. (authors)

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

    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. PMID:26234387

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

    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.

  1. Head and Tibial Acceleration as a Function of Stride Frequency and Visual Feedback during Running.

    Michael A Busa

    Full Text Available Individuals regulate the transmission of shock to the head during running at different stride frequencies although the consequences of this on head-gaze stability remain unclear. The purpose of this study was to examine if providing individuals with visual feedback of their head-gaze orientation impacts tibial and head accelerations, shock attenuation and head-gaze motion during preferred speed running at different stride frequencies. Fifteen strides from twelve recreational runners running on a treadmill at their preferred speed were collected during five stride frequencies (preferred, ±10% and ±20% of preferred in two visual task conditions (with and without real-time visual feedback of head-gaze orientation. The main outcome measures were tibial and head peak accelerations assessed in the time and frequency domains, shock attenuation from tibia to head, and the magnitude and velocity of head-gaze motion. Decreasing stride frequency resulted in greater vertical accelerations of the tibia (p<0.01 during early stance and at the head (p<0.01 during early and late stance; however, for the impact portion the increase in head acceleration was only observed for the slowest stride frequency condition. Visual feedback resulted in reduced head acceleration magnitude (p<0.01 and integrated power spectral density in the frequency domain (p<0.01 in late stance, as well as overall of head-gaze motion (p<0.01. When running at preferred speed individuals were able to stabilize head acceleration within a wide range of stride frequencies; only at a stride frequency 20% below preferred did head acceleration increase. Furthermore, impact accelerations of the head and tibia appear to be solely a function of stride frequency as no differences were observed between feedback conditions. Increased visual task demands through head gaze feedback resulted in reductions in head accelerations in the active portion of stance and increased head-gaze stability.

  2. The effects of lubricant eye drops on visual function as measured by the Inter-blink interval Visual Acuity Decay test

    Gail Torkildsen

    2009-09-01

    Full Text Available Gail TorkildsenAndover Eye Associates, Andover, MA, USAObjective: The purpose of the current study was to evaluate the effects of two marketed ocular lubricants on the visual decay in dry eye patients using the Inter-blink interval Visual Acuity Decay (IVAD test.Methods: This controlled, randomized, double-masked crossover study compared the effects of a polyethylene glycol/propylene glycol-based (PEG/PG tear and a carboxymethylcellulose sodium (CMC/glycerin tear on the visual acuity decay between blinks of dry eye patients. At visit 1 (Day 0, baseline IVAD measurements were recorded prior to instillation of a single drop of randomized study medication. IVAD testing was repeated at 15-, 45-, and 90-minutes post-instillation. Reading rate and functional blink rate were also evaluated. At the second visit (Day 7 ± 3, study procedures were repeated using crossover treatment.Results: Forty-eight (48 subjects with dry eye (61.1 ± 14.8 years old, 79.2% female, 95.8% white completed the study. Treatment with the PEG/PG-based tear demonstrated statistically significantly longer time to one-line loss of best-corrected visual acuity (BCVA as determined by the IVAD test at 90 minutes post-instillation compared to the CMC/glycerin tear (P = 0.0365. Measurements of median time at BCVA, reading rate, and functional blink rate were similar for both treatments. Both formulations were well tolerated in the population studied.Conclusions: Treatment with the PEG/PG-based tear demonstrated statistically significant improved maintenance of visual acuity between blinks at 90 minutes post-instillation compared to the CMC/glycerin tear. This is the first study to demonstrate the ability of an artificial tear to extend visual acuity maintenance between blinks, as measured by the IVAD test.Keywords: dry eye, visual function, artificial tears, ocular lubricant

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

    The relations between brain areas involved in vision were explored in 8 patients with unilateral acute optic neuritis using functional magnetic resonance imaging (f MRI) 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. Functional mapping of the human visual cortex with intravoxel incoherent motion MRI.

    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.

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

    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.

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

    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…

  7. Instructional Designer's Intentions and Learners' Perceptions of the Instructional Functions of Visuals in an e-Learning Context

    Jin, Sung-Hee; Boling, Elizabeth

    2010-01-01

    The purpose of this study is to compare an instructional designer's intentions with the learners' perceptions of the instructional functions of visuals in one specific e-learning lesson. An instructional designer created each visual with more than two purposes related to the psychological, cognitive, and affective aspects of learning. Contrary to…

  8. Math Majors' Visual Proofs in a Dynamic Environment: The Case of Limit of a Function and the ?-d Approach

    Caglayan, Günhan

    2015-01-01

    Despite few limitations, GeoGebra as a dynamic geometry software stood as a powerful instrument in helping university math majors understand, explore, and gain experiences in visualizing the limits of functions and the ?-d formalism. During the process of visualizing a theorem, the order mattered in the sequence of constituents. Students made use…

  9. Long-distance mechanism of neurotransmitter recycling mediated by glial network facilitates visual function in Drosophila.

    Chaturvedi, Ratna; Reddig, Keith; Li, Hong-Sheng

    2014-02-18

    Neurons rely on glia to recycle neurotransmitters such as glutamate and histamine for sustained signaling. Both mammalian and insect glia form intercellular gap-junction networks, but their functional significance underlying neurotransmitter recycling is unknown. Using the Drosophila visual system as a genetic model, here we show that a multicellular glial network transports neurotransmitter metabolites between perisynaptic glia and neuronal cell bodies to mediate long-distance recycling of neurotransmitter. In the first visual neuropil (lamina), which contains a multilayer glial network, photoreceptor axons release histamine to hyperpolarize secondary sensory neurons. Subsequently, the released histamine is taken up by perisynaptic epithelial glia and converted into inactive carcinine through conjugation with β-alanine for transport. In contrast to a previous assumption that epithelial glia deliver carcinine directly back to photoreceptor axons for histamine regeneration within the lamina, we detected both carcinine and β-alanine in the fly retina, where they are found in photoreceptor cell bodies and surrounding pigment glial cells. Downregulating Inx2 gap junctions within the laminar glial network causes β-alanine accumulation in retinal pigment cells and impairs carcinine synthesis, leading to reduced histamine levels and photoreceptor synaptic vesicles. Consequently, visual transmission is impaired and the fly is less responsive in a visual alert analysis compared with wild type. Our results suggest that a gap junction-dependent laminar and retinal glial network transports histamine metabolites between perisynaptic glia and photoreceptor cell bodies to mediate a novel, long-distance mechanism of neurotransmitter recycling, highlighting the importance of glial networks in the regulation of neuronal functions. PMID:24550312

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

    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. PMID:26477562

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

    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. PMID:26161466

  12. Seeing with Profoundly Deactivated Mid-level Visual Areas: Non-hierarchical Functioning in the Human Visual Cortex

    Gilaie-Dotan, Sharon; Perry, Anat; Bonneh, Yoram; Malach, Rafael; Bentin, Shlomo

    2008-01-01

    A fundamental concept in visual processing is that activity in high-order object-category distinctive regions (e.g., lateral occipital complex, fusiform face area, middle temporal+) is dependent on bottom-up flow of activity in earlier retinotopic areas (V2, V3, V4) whose main input originates from primary visual cortex (V1). Thus, activity in down stream areas should reflect lower-level inputs. Here we qualify this notion reporting case LG, a rare case of developmental object agnosia and pro...

  13. Functional brain imaging study on brain processes involved in visual awareness

    Recently, there has been great interest in visual awareness because it is thought that it may provide valuable information in understanding aspects of consciousness. An important but still controversial issue is what region in the brain is involved in visual awareness. When viewing ambiguous figures, observers can be aware of only one of multiple competing percepts at any given moment, but experience spontaneous alternations among the percepts over time. This phenomenon is known as multistable perceptions and thought to be essential in understanding the brain processes involved in visual awareness. We used functional magnetic resonance imaging to investigate the brain activities associated with multistable perceptions. Two separate experiments were performed based on two different multistable phenomena known as binocular rivalry and perceptions of ambiguous figures. Significant differential activations in the parietal and prefrontal areas were commonly observed under multistable conditions compared to monostable control conditions in the two separate experiments. These findings suggest that neural processes in the parietal and prefrontal areas may be involved in perceptual alternations in situations involving multistable phenomena. (author)

  14. Identifying and Visualizing Functional PAM Diversity across CRISPR-Cas Systems.

    Leenay, Ryan T; Maksimchuk, Kenneth R; Slotkowski, Rebecca A; Agrawal, Roma N; Gomaa, Ahmed A; Briner, Alexandra E; Barrangou, Rodolphe; Beisel, Chase L

    2016-04-01

    CRISPR-Cas adaptive immune systems in prokaryotes boast a diversity of protein families and mechanisms of action, where most systems rely on protospacer-adjacent motifs (PAMs) for DNA target recognition. Here, we developed an in vivo, positive, and tunable screen termed PAM-SCANR (PAM screen achieved by NOT-gate repression) to elucidate functional PAMs as well as an interactive visualization scheme termed the PAM wheel to convey individual PAM sequences and their activities. PAM-SCANR and the PAM wheel identified known functional PAMs while revealing complex sequence-activity landscapes for the Bacillus halodurans I-C (Cascade), Escherichia coli I-E (Cascade), Streptococcus thermophilus II-A CRISPR1 (Cas9), and Francisella novicida V-A (Cpf1) systems. The PAM wheel was also readily applicable to existing high-throughput screens and garnered insights into SpyCas9 and SauCas9 PAM diversity. These tools offer powerful means of elucidating and visualizing functional PAMs toward accelerating our ability to understand and exploit the multitude of CRISPR-Cas systems in nature. PMID:27041224

  15. Teneurin-3 Specifies Morphological and Functional Connectivity of Retinal Ganglion Cells in the Vertebrate Visual System

    Paride Antinucci

    2013-11-01

    Full Text Available A striking feature of the CNS is the precise wiring of its neuronal connections. During vertebrate visual system development, different subtypes of retinal ganglion cells (RGCs form specific connections with their corresponding synaptic partners. However, the underlying molecular mechanisms remain to be fully elucidated. Here, we report that the cell-adhesive transmembrane protein Teneurin-3 (Tenm3 is required by zebrafish RGCs for acquisition of their correct morphological and functional connectivity in vivo. Teneurin-3 is expressed by RGCs and their presynaptic amacrine and postsynaptic tectal cell targets. Knockdown of Teneurin-3 leads to RGC dendrite stratification defects within the inner plexiform layer, as well as mistargeting of dendritic processes into outer portions of the retina. Moreover, a subset of RGC axons exhibits tectal laminar arborization errors. Finally, functional analysis of RGCs targeting the tectum reveals a selective deficit in the development of orientation selectivity after Teneurin-3 knockdown. These results suggest that Teneurin-3 plays an instructive role in the functional wiring of the vertebrate visual system.

  16. [Circadian clock and non-visual functions: the role of light in humans].

    Gronfier, Claude

    2014-01-01

    Hormonal secretion, cognitive performance, motor activity, metabolic processes, the sleep wake cycle and, most recently shown, cell division and ADN repair show a 24 h rhythmicity that is driven by the circadian timing system (the biological clock). Their appropriate activity over the 24 h requires appropriate entrainment of the circadian clock, which is achieved through the synchronizing effects of ocular light exposure. The activation of melanopsin-expressing ganglion cells in the retina depends on timing, quality, intensity, and history of light exposure. Inappropriate lighting leads to inappropriate synchronization of the clock, and activation of non-visual functions (mood, wakefulness, cognition, etc.). In turn, a deficit of circadian entrainment to the 24 h is responsible for alterations of a large number of functions, and leads to altered sleep, wake, mood, neurobehavioral processes and cell division, but also to pathologies. The crucial role of the circadian clock and the nature of the non-visual functions activated by light give rise to the concept that light is a biological need fundamental to health. Without an appropriate light hygiene, the clock receives an odd tempo, and it is cacophony! PMID:25840452

  17. Pilot Study on Visual Function and Fundus Autofluorescence Assessment in Diabetic Patients

    Calvo-Maroto, Ana M.; Esteve-Taboada, José J.; Pérez-Cambrodí, Rafael J.; Madrid-Costa, David; Cerviño, Alejandro

    2016-01-01

    Purpose. Evaluate optimized fundus autofluorescence (FAF) imaging in early stages of diabetic retinopathy (DR) and relate findings with conventional colour fundus imaging and visual function in diabetic patients and control subjects. Materials and Methods. FAF and colour images were obtained using the CR-2 Plus digital nonmydriatic retinal camera in seven diabetic patients and thirteen control subjects. Visual-Functioning Questionnaire-25 (VFQ-25) and Diabetes Self-Management Questionnaire (DSMQ) were used to assess the quality of life and diabetes self-care. Contrast sensitivity function (CSF) was evaluated with the Vistech 6500 chart. Results. FAF and optimized-FAF imaging showed more retinal alterations related to DR than colour imaging. In diabetic patients, compatible signs with microaneurysms, capillary dilations, and haemorrhages were less numerous in colour imaging than optimized-FAF and FAF imaging in areas analysed. Control subjects at risk of developing DM showed more retinal pigment epithelium defects than those without risk in all retinal areas. Significant differences were not found in VFQ-25 and CSF between diabetic patients and control subjects. Conclusions. FAF and optimized-FAF imaging showed significant alterations related to DR not observed in colour imaging. FAF and optimized-FAF images could be a useful complementary tool for detecting early alterations associated with the development and progression of DR. PMID:26977312

  18. Visual function and vision-related quality of life in presbyopic adult population of Northwestern Nigeria

    Nasiru Muhammad; Alhassan, Mahmoud B; Murtala M Umar

    2015-01-01

    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 ...

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

    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.

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

    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.

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

    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

  2. A rhodopsin-guanylyl cyclase gene fusion functions in visual perception in a fungus.

    Avelar, Gabriela M; Schumacher, Robert I; Zaini, Paulo A; Leonard, Guy; Richards, Thomas A; Gomes, Suely L

    2014-06-01

    Sensing light is the fundamental property of visual systems, with vision in animals being based almost exclusively on opsin photopigments [1]. Rhodopsin also acts as a photoreceptor linked to phototaxis in green algae [2, 3] and has been implicated by chemical means as a light sensor in the flagellated swimming zoospores of the fungus Allomyces reticulatus [4]; however, the signaling mechanism in these fungi remains unknown. Here we use a combination of genome sequencing and molecular inhibition experiments with light-sensing phenotype studies to examine the signaling pathway involved in visual perception in the closely related fungus Blastocladiella emersonii. Our data show that in these fungi, light perception is accomplished by the function of a novel gene fusion (BeGC1) of a type I (microbial) rhodopsin domain and guanylyl cyclase catalytic domain. Photobleaching of rhodopsin function prevents accumulation of cGMP levels and phototaxis of fungal zoospores exposed to green light, whereas inhibition of guanylyl cyclase activity negatively affects fungal phototaxis. Immunofluorescence microscopy localizes the BeGC1 protein to the external surface of the zoospore eyespot positioned close to the base of the swimming flagellum [4, 5], demonstrating this is a photoreceptive organelle composed of lipid droplets. Taken together, these data indicate that Blastocladiomycota fungi have a cGMP signaling pathway involved in phototaxis similar to the vertebrate vision-signaling cascade but composed of protein domain components arranged as a novel gene fusion architecture and of distant evolutionary ancestry to type II rhodopsins of animals. PMID:24835457

  3. Visual hierarchical processing and lateralization of cognitive functions through domestic chicks' eyes.

    Cinzia Chiandetti

    Full Text Available Hierarchical stimuli have proven effective for investigating principles of visual organization in humans. A large body of evidence suggests that the analysis of the global forms precedes the analysis of the local forms in our species. Studies on lateralization also indicate that analytic and holistic encoding strategies are separated between the two hemispheres of the brain. This raises the question of whether precedence effects may reflect the activation of lateralized functions within the brain. Non-human animals have perceptual organization and functional lateralization that are comparable to that of humans. Here we trained the domestic chick in a concurrent discrimination task involving hierarchical stimuli. Then, we evaluated the animals for analytic and holistic encoding strategies in a series of transformational tests by relying on a monocular occlusion technique. A local precedence emerged in both the left and the right hemisphere, adding further evidence in favour of analytic processing in non-human animals.

  4. Visual hierarchical processing and lateralization of cognitive functions through domestic chicks' eyes.

    Chiandetti, Cinzia; Pecchia, Tommaso; Patt, Francesco; Vallortigara, Giorgio

    2014-01-01

    Hierarchical stimuli have proven effective for investigating principles of visual organization in humans. A large body of evidence suggests that the analysis of the global forms precedes the analysis of the local forms in our species. Studies on lateralization also indicate that analytic and holistic encoding strategies are separated between the two hemispheres of the brain. This raises the question of whether precedence effects may reflect the activation of lateralized functions within the brain. Non-human animals have perceptual organization and functional lateralization that are comparable to that of humans. Here we trained the domestic chick in a concurrent discrimination task involving hierarchical stimuli. Then, we evaluated the animals for analytic and holistic encoding strategies in a series of transformational tests by relying on a monocular occlusion technique. A local precedence emerged in both the left and the right hemisphere, adding further evidence in favour of analytic processing in non-human animals. PMID:24404163

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

    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.

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

    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.)

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

    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.

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

    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

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

    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.

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

    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.

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

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

    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.

  14. 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)

    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.

  15. On sex-related differences in auditory and visual sensory functioning.

    Rammsayer, Thomas H; Troche, Stefan J

    2012-06-01

    The present study was designed to elucidate sex-related differences in two basic auditory and one basic visual aspect of sensory functioning, namely sensory discrimination of pitch, loudness, and brightness. Although these three aspects of sensory functioning are of vital importance in everyday life, little is known about whether men and women differ from each other in these sensory functions. Participants were 100 male and 100 female volunteers ranging in age from 18 to 30 years. Since sensory sensitivity may be positively related to individual levels of intelligence and musical experience, measures of psychometric intelligence and musical background were also obtained. Reliably better performance for men compared to women was found for pitch and loudness, but not for brightness discrimination. Furthermore, performance on loudness discrimination was positively related to psychometric intelligence, while pitch discrimination was positively related to both psychometric intelligence and levels of musical training. Additional regression analyses revealed that each of three predictor variables (sex, psychometric intelligence, and musical training) accounted for a statistically significant portion of unique variance in pitch discrimination. With regard to loudness discrimination, regression analysis yielded a statistically significant portion of unique variance for sex as a predictor variable, whereas psychometric intelligence just failed to reach statistical significance. The potential influence of sex hormones on sex-related differences in sensory functions is discussed. PMID:22183583

  16. A comparison of visual acuity, predictability, and visual function outcomes after intracorneal ring segments and laser in situ keratomileusis.

    Suiter, B G; Twa, M D; Ruckhofer, J; Schanzlin, D J

    2000-01-01

    PURPOSE: To compare correction of low myopia by intrastromal corneal ring segments (ICRS) and by laser in situ keratomileusis (LASIK) with respect to early visual recovery and refractive outcomes. METHODS: Eighty-two eyes implanted with ICRS in a phase III study for US Food and Drug Administration review were matched with 133 eyes treated with LASIK by criteria of age (> 18 years, < 65 years), preoperative myopia (-1.00 to -3.50 diopters [D]), astigmatism (< or = 1.00 D), single treatment, an...

  17. Combination of blood oxygen level–dependent functional magnetic resonance imaging and visual evoked potential recordings for abnormal visual cortex in two types of amblyopia

    Wang, Xinmei; Cui, Dongmei; Zheng, Ling; Yang, Xiao; Yang, Hui; Zeng, Junwen

    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...

  18. Functional topography of converging visual and auditory inputs to neurons in the rat superior colliculus.

    Skaliora, Irini; Doubell, Timothy P; Holmes, Nicholas P; Nodal, Fernando R; King, Andrew J

    2004-11-01

    We have used a slice preparation of the infant rat midbrain to examine converging inputs onto neurons in the deeper multisensory layers of the superior colliculus (dSC). Electrical stimulation of the superficial visual layers (sSC) and of the auditory nucleus of the brachium of the inferior colliculus (nBIC) evoked robust monosynaptic responses in dSC cells. Furthermore, the inputs from the sSC were found to be topographically organized as early as the second postnatal week and thus before opening of the eyes and ear canals. This precocious topography was found to be sculpted by GABAA-mediated inhibition of a more widespread set of connections. Tracer injections in the nBIC, both in coronal slices as well as in hemisected brains, confirmed a robust projection originating in the nBIC with distinct terminals in the proximity of the cell bodies of dSC neurons. Combined stimulation of the sSC and nBIC sites revealed that the presumptive visual and auditory inputs are summed linearly. Finally, whereas either input on its own could manifest a significant degree of paired-pulse facilitation, temporally offset stimulation of the two sites revealed no synaptic interactions, indicating again that the two inputs function independently. Taken together, these data provide the first detailed intracellular analysis of convergent sensory inputs onto dSC neurons and form the basis for further exploration of multisensory integration and developmental plasticity. PMID:15229210

  19. Word-decoding as a function of temporal processing in the visual system.

    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.

  20. Visual analysis of hepatic function by a scoring system using 99mTc-GSA

    To establish a simple hepatic function test, a five-point scoring system using 99mTc-galactosyl-human serum albumin (GSA) was applied to seventy-six patients with or suspected with hepatic dysfunction. Dynamic data at rest were obtained immediately and 30 minutes after intravenous bolus injection of 99mTc-GSA (185 MBq). Regions of interest (ROIs) were superimposed over the images of the liver and the entire heart. A visual analysis using a image taken 5 to 6 minutes after radiotracer injection was performed by the three observers blinded to the clinical information to assess their agreement or disagreement on the grading score. κ-Test was used to evaluate the goodness of agreement. Three pairs in the first reading showed excellent interobserver agreement (0.92 mean κ-value). Three pairs in the first and second reading also showed excellent intraobserver agreement (0.89 mean κ-value). Data were also analyzed for correlations with heart/liver count ratio, ICG R15, LHL15, Alb, TB, PT, HPT and ZTT. There were good correlations between visual grading score and ICG R15 (Rs=0.619, p99mTc-GSA uptake is a useful indicator for hepatic dysfunction in a clinical setting. (author)

  1. Visual detection of arginine, histidine and lysine using quercetin-functionalized gold nanoparticles

    We report on the use of quercetin-functionalized gold nanoparticles (QC-AuNPs) as a colorimetric probe for the amino acids arginine (Arg), histidine (His) and lysine (Lys). The method is based on the aggregation of the QC-AuNPs that is caused by these amino acids and leads to a visually detectable color change from red to blue. The absorption maxima shift from 525 nm to 702, 693, and 745 nm, respectively. Aggregations are confirmed by dynamic light scattering (DLS) and transmission electron microscopic techniques (TEM). The effects of the QC concentration, temperature and reaction time for the preparation of QC-Au NPs were tested. Other amino acids do not interfere. Under the optimal conditions, linear relationships exist between the absorption ratios at 702/525 nm (for Arg), 693/525 nm (for His), and 745/525 nm (for Lys) over the concentrations ranges from 2.5–1,250 μM (Arg) and 1–1,000 μM (His and Lys), respectively. The respective limits of detection are 0.04, 0.03, and 0.02 μM. The method provides a useful tool for the rapid visual and instrumental determination of the three amino acids. (author)

  2. [Functional characteristics of the hippocampus after switching off visual afferentation in early ontogenesis].

    Nikitina, G M; Boravova, A I

    1977-01-01

    EEG reactions to afferent stimuli and the driving responses (DR) to photic flickering with 1-15 sec frequency were studied in different brain structures of rabbits lacking visual experience (from the 8th to the 23rd and from the 57th to the 90th day of life). The orienting reaction in the first few days of the light regime is characterized by enhanced motor and respiratory components and is not extinguished for a long time when the stimulus is repeated. It is attended with theta-rhythm in the hippocampus EEG and desynchronized activity in the neocortical areas. DR is characterized by spatial-temporal dissociation; its development is markedly retarded in the cortical projection zone of the visual system, and of the archicortex structures, in the dentate fascia, as compared with the hippocampus proper, the midbrain reticular formation and the auditory cortex. The DR index equals the level of that of the control animals after nine to twelve days of their life in the light. The results obtained attest that the observed differences in the changes of the functional characteristics of the hippocampus and other brain structures depend on the mode of the central organization of the reaction, whose correlate is the studied EEG-parameter. PMID:899266

  3. Visual Predictive Check in Models with Time-Varying Input Function.

    Largajolli, Anna; Bertoldo, Alessandra; Campioni, Marco; Cobelli, Claudio

    2015-11-01

    The nonlinear mixed effects models are commonly used modeling techniques in the pharmaceutical research as they enable the characterization of the individual profiles together with the population to which the individuals belong. To ensure a correct use of them is fundamental to provide powerful diagnostic tools that are able to evaluate the predictive performance of the models. The visual predictive check (VPC) is a commonly used tool that helps the user to check by visual inspection if the model is able to reproduce the variability and the main trend of the observed data. However, the simulation from the model is not always trivial, for example, when using models with time-varying input function (IF). In this class of models, there is a potential mismatch between each set of simulated parameters and the associated individual IF which can cause an incorrect profile simulation. We introduce a refinement of the VPC by taking in consideration a correlation term (the Mahalanobis or normalized Euclidean distance) that helps the association of the correct IF with the individual set of simulated parameters. We investigate and compare its performance with the standard VPC in models of the glucose and insulin system applied on real and simulated data and in a simulated pharmacokinetic/pharmacodynamic (PK/PD) example. The newly proposed VPC performance appears to be better with respect to the standard VPC especially for the models with big variability in the IF where the probability of simulating incorrect profiles is higher. PMID:26265094

  4. Visual Function and Its Relationship with Severity of Early, and Activity of Neovascular, Age-Related Macular Degeneration

    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...

  5. Data-driven visualization and group analysis of multichannel EEG coherence with functional units.

    ten Caat, Michael; 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, we define a functional unit (FU) as a data-driven region of interest (ROI). An FU is a spatially connected set of electrodes recording pairwise significantly coherent signals, represented in the coherence graph by a spatially connected clique. Earlier we presented two methods to detect FUs: a maximal clique based (MCB) method (time complexity O(3n/3), with n being the number of vertices) and a more efficient watershed based (WB) method (time complexity O (n2 log n)). To reduce the potential over-segmentation of the WB method, we introduce here an improved WB (IWB) method (time complexity O(n2 log n)). The IWB method merges basins representing FUs during the segmentation if they are spatially connected and if their union is a clique. The WB and IWB methods are both up to a factor of 100,000 faster than the MCB method for a typical multichannel setting with 128 EEG channels, thus making interactive visualization of multichannel EEG coherence possible. Results show that considering the MCB method as the gold standard, the difference between IWB and MCB FU maps is smaller than between WB and MCB FU maps. We also introduce two novel group maps for data-driven group analysis as extensions of the IWB method. First, the group mean coherence map preserves dominant features from a collection of individual FU maps. Second, the group FU size map visualizes the average FU size per electrode across a collection of individual FU maps. Finally, we employ an extensive case study to evaluate the IWB FU map and the two new group maps for data-driven group analysis. Results, in accordance with the conventional findings, indicate differences in EEG coherence between younger and older adults

  6. BIOCHEMISTRY IN THE SPECIALTY IN VISUAL FUNCTION, AND VIRTUAL ENVIRONMENTS IN THE CICS UMA-IPN

    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.

  7. Disturbance of visual functions as a result of temporary blinding from low power lasers

    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

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

    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 18F-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.)

  9. Visual function and vision-related quality of life in presbyopic adult population of Northwestern Nigeria

    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.

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

    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.)

  11. Gross motor function, functional skills and caregiver assistance in children with spastic cerebral palsy (CP) with and without cerebral visual impairment (CVI)

    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

  12. Sociocultural materials and visual art: A functional analysis of Nigerian banknotes, 1973–2009

    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.

  13. Visualization Laboratory

    Federal Laboratory Consortium — FUNCTION: Evaluates and improves the operational effectiveness of existing and emerging electronic warfare systems. By analyzing and visualizing simulation results...

  14. Structural dynamics of synapses in vivo correlate with functional changes during experience-dependent plasticity in visual cortex.

    Tropea, Daniela; Majewska, Ania K; Garcia, Rodrigo; Sur, Mriganka

    2010-08-18

    The impact of activity on neuronal circuitry is complex, involving both functional and structural changes whose interaction is largely unknown. We have used optical imaging of mouse visual cortex responses and two-photon imaging of superficial layer spines on layer 5 neurons to monitor network function and synaptic structural dynamics in the mouse visual cortex in vivo. Total lack of vision due to dark-rearing from birth dampens visual responses and shifts spine dynamics and morphologies toward an immature state. The effects of vision after dark rearing are strongly dependent on the timing of exposure: over a period of days, functional and structural changes are temporally related such that light stabilizes spines while increasing visually driven activity. The effects of long-term light exposure can be partially mimicked by experimentally enhancing inhibitory signaling in the darkness. Brief light exposure, however, results in a rapid, transient, NMDA-dependent increase of cortical responses, accompanied by increased dynamics of dendritic spines. These findings indicate that visual experience induces rapid reorganization of cortical circuitry followed by a period of stabilization, and demonstrate a close relationship between dynamic changes at single synapses and cortical network function. PMID:20720116

  15. A survey of visual function in an Austrian population of school-age children with reading and writing difficulties

    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.

  16. Visuospatial Function in Early Alzheimer’s Disease—The Use of the Visual Object and Space Perception (VOSP) Battery

    Quental, Natália Bezerra Mota; Brucki, Sonia Maria Dozzi; Bueno, Orlando Francisco Amodeo

    2013-01-01

    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 visuospa...

  17. Functional Asymmetries Revealed in Visually Guided Saccades: An fMRI Study

    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

  18. Executive Function, Visual Attention and the Cocktail Party Problem in Musicians and Non-Musicians

    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

  19. Radiation therapy for primary carcinoma of the eyelid. Tumor control and visual function

    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.)

  20. A Simple Behavioral Assay for Testing Visual Function in Xenopus laevis

    Viczian, Andrea S.; Zuber, Michael E.

    2014-01-01

    Measurement of the visual function in the tadpoles of the frog, Xenopus laevis, allows screening for blindness in live animals. The optokinetic response is a vision-based, reflexive behavior that has been observed in all vertebrates tested. Tadpole eyes are small so the tail flip response was used as alternative measure, which requires a trained technician to record the subtle response. We developed an alternative behavior assay based on the fact that tadpoles prefer to swim on the white side of a tank when placed in a tank with both black and white sides. The assay presented here is an inexpensive, simple alternative that creates a response that is easily measured. The setup consists of a tripod, webcam and nested testing tanks, readily available in most Xenopus laboratories. This article includes a movie showing the behavior of tadpoles, before and after severing the optic nerve. In order to test the function of one eye, we also include representative results of a tadpole in which each eye underwent retinal axotomy on consecutive days. Future studies could develop an automated version of this assay for testing the vision of many tadpoles at once. PMID:24962702

  1. Radiation therapy for primary carcinoma of the eyelid. Tumor control and visual function

    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.)

  2. 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"

    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.

  3. Functional connectivity supporting the selective maintenance of feature-location binding in visual working memory.

    Takahama, Sachiko; Saiki, Jun

    2014-01-01

    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. PMID:24917833

  4. Functional connectivity supporting the selective maintenance of feature-location binding in visual working memory

    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.

  5. 葡萄膜炎的视功能预后%Prognosis of visual function of uveitis

    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. Psychophysical measures of visual function and everyday perceptual experience in a case of congenital stationary night blindness.

    Cammack, Jocelyn; Whight, John; Cross, Vinette; Rider, Andrew T; Webster, Andrew R; Stockman, Andrew

    2016-01-01

    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 suitability of filmmaking techniques as a means of accessing and communicating subjective patient experience. PMID:27601873

  7. Emotion Recognition in Faces and the Use of Visual Context in Young People with High-Functioning Autism Spectrum Disorders

    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…

  8. Demonstration of decreased functional activity of visual cortex by [11C]methylglucose and positron emission tomography

    A hemorrhagic infarction which caused left hemiparesis and homonymous hemianopia was demonstrated as a hypodense lesion on the first CT; 2 weeks later it was hyperdense and enhanced after injecting meglumine. Positron emission tomography with [11C]methyl-D-glucose also revealed the ischemic lesion, but also marked decrease of glucose uptake in the visual cortex, which indicated decreased functional activity. (orig.)

  9. The effectiveness of racket-sport intervention on visual perception and executive functions in children with mild intellectual disabilities and borderline intellectual functioning

    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

  10. Hydrologic-Process-Based Soil Texture Classifications for Improved Visualization of Landscape Function.

    Derek G Groenendyk

    Full Text Available Soils lie at the interface between the atmosphere and the subsurface and are a key component that control ecosystem services, food production, and many other processes at the Earth's surface. There is a long-established convention for identifying and mapping soils by texture. These readily available, georeferenced soil maps and databases are used widely in environmental sciences. Here, we show that these traditional soil classifications can be inappropriate, contributing to bias and uncertainty in applications from slope stability to water resource management. We suggest a new approach to soil classification, with a detailed example from the science of hydrology. Hydrologic simulations based on common meteorological conditions were performed using HYDRUS-1D, spanning textures identified by the United States Department of Agriculture soil texture triangle. We consider these common conditions to be: drainage from saturation, infiltration onto a drained soil, and combined infiltration and drainage events. Using a k-means clustering algorithm, we created soil classifications based on the modeled hydrologic responses of these soils. The hydrologic-process-based classifications were compared to those based on soil texture and a single hydraulic property, Ks. Differences in classifications based on hydrologic response versus soil texture demonstrate that traditional soil texture classification is a poor predictor of hydrologic response. We then developed a QGIS plugin to construct soil maps combining a classification with georeferenced soil data from the Natural Resource Conservation Service. The spatial patterns of hydrologic response were more immediately informative, much simpler, and less ambiguous, for use in applications ranging from trafficability to irrigation management to flood control. The ease with which hydrologic-process-based classifications can be made, along with the improved quantitative predictions of soil responses and visualization

  11. Hydrologic-Process-Based Soil Texture Classifications for Improved Visualization of Landscape Function.

    Groenendyk, Derek G; Ferré, Ty P A; Thorp, Kelly R; Rice, Amy K

    2015-01-01

    Soils lie at the interface between the atmosphere and the subsurface and are a key component that control ecosystem services, food production, and many other processes at the Earth's surface. There is a long-established convention for identifying and mapping soils by texture. These readily available, georeferenced soil maps and databases are used widely in environmental sciences. Here, we show that these traditional soil classifications can be inappropriate, contributing to bias and uncertainty in applications from slope stability to water resource management. We suggest a new approach to soil classification, with a detailed example from the science of hydrology. Hydrologic simulations based on common meteorological conditions were performed using HYDRUS-1D, spanning textures identified by the United States Department of Agriculture soil texture triangle. We consider these common conditions to be: drainage from saturation, infiltration onto a drained soil, and combined infiltration and drainage events. Using a k-means clustering algorithm, we created soil classifications based on the modeled hydrologic responses of these soils. The hydrologic-process-based classifications were compared to those based on soil texture and a single hydraulic property, Ks. Differences in classifications based on hydrologic response versus soil texture demonstrate that traditional soil texture classification is a poor predictor of hydrologic response. We then developed a QGIS plugin to construct soil maps combining a classification with georeferenced soil data from the Natural Resource Conservation Service. The spatial patterns of hydrologic response were more immediately informative, much simpler, and less ambiguous, for use in applications ranging from trafficability to irrigation management to flood control. The ease with which hydrologic-process-based classifications can be made, along with the improved quantitative predictions of soil responses and visualization of landscape

  12. How art changes your brain: differential effects of visual art production and cognitive art evaluation on functional brain connectivity.

    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. PMID:24983951

  13. How art changes your brain: differential effects of visual art production and cognitive art evaluation on functional brain connectivity.

    Anne Bolwerk

    Full Text Available 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.

  14. Is the NEI-VFQ-25 a useful tool in identifying visual impairment in an elderly population?

    Wormald Richard PL

    2006-06-01

    Full Text Available Abstract Background The use of self-report questionnaires to substitute for visual acuity measurement has been limited. We examined the association between visual impairment and self reported visual function in a population sample of older people in the UK. Methods Cross sectional study of people aged more than 75 years who initially participated in a trial of health screening. The association between 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ scores and visual impairment (defined as an acuity of less than 6/18 in the better eye was examined using logistic regression. Results Visual acuity and NEI-VFQ scores were obtained from 1807 participants (aged 77 to 101 years, 36% male, from 20 general practices throughout the UK. After adjustment for age, gender, practice and NEI-VFQ sub-scale scores, those complaining of poor vision in general were 4.77 times (95% CI 3.03 to 7.53 more likely to be visually impaired compared to those who did not report difficulty. Self-reported limitations with social functioning and dependency on others due to poor vision were also associated with visual impairment (odds ratios, 2.52, 95% CI 1.55 to 4.11; 1.73, 95% CI 1.05 to 2.86 respectively. Those reporting difficulties with near vision and colour vision were more likely to be visually impaired (odds ratios, 2.32, 95% CI 1.30 to 4.15; 2.25, 95% CI 1.35 to 3.73 respectively. Other NEI-VFQ sub-scale scores were unrelated to measures of acuity. Similar but weaker odds ratios were found with reduced visual acuity (defined as less than 6/12 in the better eye. Although differences in NEI-VFQ scores were small, scores were strongly associated with visual acuity, binocular status, and difference in acuity between eyes. Conclusion NEI-VFQ questions regarding the quality of general vision, social functioning, visual dependency, near vision and colour vision are strongly and independently associated with an objective measure of visual impairment in an

  15. Early Detection of Central Visual Function Decline in Cone-RodDystrophy by the use of Macular Focal Cone Electroretinogram

    Resta, Giovanni; Galli-Resta, Lucia; Piccardi, Marco; Ziccardi, Lucia; Fadda, Antonello; Minnella, Angelo; Marangoni, Dario; Placidi, Giorgio; Falsini, Benedetto

    2013-01-01

    PURPOSE:To evaluate macular focal cone ERG (fERG) as a tool for reliable and early detection of central retinal function decay in cone-rod dystrophy (CRD).RESULTS:Macular focal cone ERG follow-up allowed a clear-cut identification of CRD patients as stationary or progressive, in agreement with visual acuity follow-up. In all progressive patients, fERG declined whenever visual acuity declined, and--in 50% of the cases--fERG loss anticipated acuity loss of several years.CONCLUSIONS:Macular foca...

  16. Post-exercise syncope: Wingate syncope test and visual-cognitive function.

    Sieck, Dylan C; Ely, Matthew R; Romero, Steven A; Luttrell, Meredith J; Abdala, Pedro M; Halliwill, John R

    2016-08-01

    Adequate cerebral perfusion is necessary to maintain consciousness in upright humans. Following maximal anaerobic exercise, cerebral perfusion can become compromised and result in syncope. It is unknown whether post-exercise reductions in cerebral perfusion can lead to visual-cognitive deficits prior to the onset of syncope, which would be of concern for emergency workers and warfighters, where critical decision making and intense physical activity are combined. Therefore, the purpose of this experiment was to determine if reductions in cerebral blood velocity, induced by maximal anaerobic exercise and head-up tilt, result in visual-cognitive deficits prior to the onset of syncope. Nineteen sedentary to recreationally active volunteers completed a symptom-limited 60° head-up tilt for 16 min before and up to 16 min after a 60 sec Wingate test. Blood velocity of the middle cerebral artery was measured using transcranial Doppler ultrasound and a visual decision-reaction time test was assessed, with independent analysis of peripheral and central visual field responses. Cerebral blood velocity was 12.7 ± 4.0% lower (mean ± SE; P exercise compared to pre-exercise. This was associated with a 63 ± 29% increase (P exercise contributes to visual-cognitive deficits in the peripheral visual field without an apparent affect to the central visual field. PMID:27550986

  17. Ocular status and functional adaptation of visually challenged children of a special school in Oman

    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.

  18. Avaliação da função visual em pacientes com distrofia de cones Visual function assessment in patients with cone dystrophy

    Marta Sato

    2003-06-01

    Full Text Available OBJETIVO: Avaliar a função visual pela eletrorretinografia de campo total e pela acuidade visual em pacientes com distrofia de cones. MÉTODOS: Um grupo de 23 pacientes (16 do sexo feminino e 7 do sexo masculino com distrofia de cones foi avaliado no Laboratório de Eletrofisiologia Visual Clínica do Departamento de Oftalmologia da Universidade Federal de São Paulo. A avaliação constou de: sinais e sintomas, acuidade visual medida pela tabela ETDRS ou de Snellen e função retiniana pela eletrorretinografia de campo total. As amplitudes pico-a-pico (µV e o tempo de culminação da onda-b (ms foram comparadas com normas descritas na literatura. RESULTADOS: A acuidade visual no melhor olho variou de 0,07 a 3,00 logMAR (20/25-MM a 10 cm, com média de 0,85±0,64 logMAR (20/140. A média da amplitude pico-a-pico das respostas escotópicas de bastonetes foi de 144,29±80,05 µV com média do tempo de culminação da onda-b de 92,85±9,02 ms (normal para a idade. A média da amplitude pico-a-pico para respostas fotópicas de cones foi de 5,06±8,59 µV (reduzida para a idade com média do tempo de culminação da onda-b de 43,4±14,5 ms (atrasado para a idade nos pacientes com resposta detectável e para as respostas do flicker, a amplitude foi de 5,00±9,00 µV (reduzida para a idade com média do tempo de culminação da onda-b de 32,90±12,87 ms (atrasado para a idade. CONCLUSÃO: A acuidade visual média encontrada neste grupo de pacientes com distrofia de cones foi de 0,85 logMAR (20/140. A fotofobia foi o sintoma mais freqüente juntamente com a baixa de visão e deficiência de visão de cores. Em 10/23 pacientes o diagnóstico foi feito pela eletrorretinografia, devido à ausência de alterações fundoscópicas.PURPOSE: To evaluate visual function by full-field electroretinography (ERG and visual acuity in patients with cone dystrophy. METHODS: 23 (7 male and 16 female patients with suspicion of cone dystrophy were evaluated at the

  19. VisualTAPAS: an example of density functional theory assisted understanding and simulation of anisotropic etching (abstract only)

    VisualTAPAS is a self-contained, user-friendly, graphical user interface based simulator of wet etching and deep reactive ion etching with multi-masking capabilities, built upon an octree representation of the silicon substrate (www.fyslab.hut.fi/~mag/VisualTAPAS/Home.html). The program allows the use of a wide range of kinetic Monte Carlo (KMC) and cellular automata time-evolution algorithms, including a fast octree search algorithm for the KMC simulations. 'VisualTAPAS' stands for 'visual three-dimensional anisotropic processing at all scales'. The use of the term 'visual' stresses the interactive visual capabilities of the program. Here, a brief history of the evolution of VisualTAPAS as a research tool will be presented: from the initial efforts, explaining the anisotropy of wet etching as a result of steric hindrance using a combination of density functional theory (DFT) and KMC simulations, to the most recent implementation, focusing on the propagation of the etch front for engineering applications by making use of the analytical solution of the continuous cellular automaton (CCA) method; and in between, a recent example of DFT assisted understanding of the effects of metal impurities on the surface morphology of the etched surfaces will be presented. We try to bridge together three complementary simulation tools, namely, DFT, KMC and CCA methods. Our experience with the use of the three methods for the simulation of anisotropic etching shows that DFT is very useful and, many times, an unavoidable approach. Similarly, the KMC approach is the method of choice for understanding the large variety of etched surface morphologies while the CCA is an outstanding tool for the simulation of the process at an engineering level

  20. Probing the early development of visual working memory capacity with functional near-infrared spectroscopy.

    Buss, Aaron T; Fox, Nicholas; Boas, David A; Spencer, John P

    2014-01-15

    Visual working memory (VWM) is a core cognitive system with a highly limited capacity. The present study is the first to examine VWM capacity limits in early development using functional neuroimaging. We recorded optical neuroimaging data while 3- and 4-year-olds completed a change detection task where they detected changes in the shapes of objects after a brief delay. Near-infrared sources and detectors were placed over the following 10-20 positions: F3 and F5 in left frontal cortex, F4 and F6 in right frontal cortex, P3 and P5 in left parietal cortex, and P4 and P6 in right parietal cortex. The first question was whether we would see robust task-specific activation of the frontal-parietal network identified in the adult fMRI literature. This was indeed the case: three left frontal channels and 11 of 12 parietal channels showed a statistically robust difference between the concentration of oxygenated and deoxygenated hemoglobin following the presentation of the sample array. Moreover, four channels in the left hemisphere near P3, P5, and F5 showed a robust increase as the working memory load increased from 1 to 3 items. Notably, the hemodynamic response did not asymptote at 1-2 items as expected from previous fMRI studies with adults. Finally, 4-year-olds showed a more robust parietal response relative to 3-year-olds, and an increasing sensitivity to the memory load manipulation. These results demonstrate that fNIRS is an effective tool to study the neural processes that underlie the early development of VWM capacity. PMID:23707803

  1. Visual functional effects of constant blue light in a retinal degenerate rat model

    Thomas, BB; Seiler, MJ; Aramant, RB; Samant, D; Qiu, G; Vyas, N; Arai, S.; Chen, Z.; Sadda, SR

    2007-01-01

    Retinal degenerative conditions increase susceptibility to light damage, but rapid retinal degeneration (RD) models show less susceptibility to cyclic dim light. We investigated whether constant blue light (BL) exposure can eliminate the residual visual responses in a comparatively rapid RD rat model. Pigmented rhodopsin mutant S334ter line-3 rat pups (21 days old) were exposed for 5-6 consecutive days to constant BL. Visual behavior was evaluated with an optokinetic head tracking apparatus. ...

  2. Alberto Cairo: The Functional Art. An introduction to information graphics and visualization, Berkeley 2012

    Osińska, Veslava

    2015-01-01

    Review of the first book to offer a broad, hands-on introduction to information graphics and visualization, the use of charts, maps, diagrams, and illustrations to communicate and understand data and phenomena. Alberto Cairo, who teaches at the University of Miami, explains that visualizations should be conceived as tools that extend human perception, letting go beyond what the bare eye can see, and allow to identify patterns and trends that would be invisible otherwise. Recenzja pierwszej...

  3. Holographic interferometry used for visualization of the function of Thermoacoustic prime mover

    Lédl, Vít; Vít, Tomáš; Trávníček, Zdeněk; Chen, Y.-C.; Maršík, František; Wang, A.B.

    Kaohsiung : National Pingtung University of Science and Technolog, 2009 - (Tai, C.), s. 21-22 ISBN N. [Pacific Symposium on Flow Visualization and Image Processing /7./ (PSFVIP-7 2009). Kaohsiung (TW), 16.11.2009-19.11.2009] R&D Projects: GA AV ČR(CZ) IAA200760801; GA MŠk(CZ) 1M06031 Institutional research plan: CEZ:AV0Z20760514; CEZ:AV0Z20430508 Keywords : holografic interferometry * thermoacoustic, visualization Subject RIV: BJ - Thermodynamic s

  4. ProViz-a web-based visualization tool to investigate the functional and evolutionary features of protein sequences.

    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/. PMID:27085803

  5. Functional dissociation between action and perception of object shape in developmental visual object agnosia.

    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. PMID:26827163

  6. The Effect of Learning on the Function of Monkey Extrastriate Visual Cortex

    Rainer Gregor

    2004-01-01

    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.

  7. The effect of learning on the function of monkey extrastriate visual cortex.

    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.

  8. Visual and colorimetric detection of Hg(2+) by cloud point extraction with functionalized gold nanoparticles as a probe.

    Tan, Zhi-qiang; Liu, Jing-fu; Liu, Rui; Yin, Yong-guang; Jiang, Gui-bin

    2009-12-01

    Association with Hg(2+) enhances the hydrophobicity and triggers the cloud point extraction of approximately 4 nm-diameter gold nanoparticle probes functionalized with mercaptopropionic acid and homocystine, which results in the color change of the TX-114-rich phase from colorless to red, and therefore provides a novel approach for visual and colorimetric detection of Hg(2+) with ultrahigh sensitivity and selectivity. PMID:19904384

  9. Refractive error and visual functions in children with special needs compared with the first grade school students in Oman

    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.

  10. Comparative study of visual functions in premature pre-school children with and without retinopathy of prematurity

    Lígia Beatriz Bonotto; Ana Tereza Ramos Moreira; Silvia Chuffi; Susana Maria Bittencourt Sckudlarek

    2014-01-01

    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 gestatio...

  11. Morphology of Single Geniculocortical Afferents and Functional Recovery of the Visual Cortex after Reverse Monocular Deprivation in the Kitten

    Antonini, Antonella; Gillespie, Deda C; Crair, Michael C.; Stryker, Michael P.

    1998-01-01

    To investigate the possible anatomical basis for the functional recovery of visual cortical responses after reverse monocular deprivation, we have studied the morphology of single geniculocortical afferents to area 17. In kittens reverse-sutured for 10 d after an initial week of monocular deprivation, single-unit and intrinsic signal optical recordings confirmed that the effects of the initial deprivation were largely reversed. Responses through the originally nondeprived (OND) eye were drast...

  12. 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

    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.

  13. Postoperative changes in visual evoked potentials and cognitive function tests following sevoflurane anaesthesia.

    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.

  14. Three-dimensional visualization of functional brain tissue and functional magnetic resonance imaging-integrated neuronavigation in the resection of brain tumor adjacent to motor cortex

    Objective: To assess the value of three -dimensional visualization of functional brain tissue and the functional magnetic resonance imaging (fMRI)-integrated neuronavigation in the resection of brain tumor adjacent to motor cortex. Method: Sixty patients with tumor located in the central sulcus were enrolled. Thirty patients were randomly assigned to function group and 30 to control group. Patients in function group underwent fMRI to localize the functional brain tissues. Then the function information was transferred to the neurosurgical navigator. The patients in control group underwent surgery with navigation without function information. The therapeutic effect, excision rate. improvement of motor function, and survival quality during follow-up were analyzed. Result: All patients in function group were accomplished visualization of functional brain tissues and fMRI-integrated neuronavigation. The locations of tumors, central sulcus and motor cortex were marked during the operation. The fMRI -integrated information played a great role in both pre- and post-operation. Pre-operation: designing the location of the skin flap and window bone, determining the relationship between the tumor and motor cortex, and designing the pathway for the resection. Post- operation: real-time navigation of relationship between the tumor and motor cortex, assisting to localize the motor cortex using interoperation ultra-sound for correcting the displacement by the CSF outflow and collapsing tumor. The patients in the function group had better results than the patients in the control group in therapeutic effect (u=2.646, P=0.008), excision rate (χ=7.200, P<0.01), improvement of motor function (u=2.231, P=0.026), and survival quality (KPS uc= 2.664, P=0.008; Zubrod -ECOG -WHO uc=2.135, P=0.033). Conclusions: Using preoperative three -dimensional visualization of cerebral function tissue and the fMRI-integrated neuronavigation technology, combining intraoperative accurate positioning

  15. Neural Responses to Visual Food Cues According to Weight Status: A Systematic Review of Functional Magnetic Resonance Imaging Studies

    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.

  16. Increasing a Functional Skill for an Adolescent with Cortical Visual Impairment.

    Farrenkopf, C.; McGregor, D.; Nes, S. L.; Koenig, A. J.

    1997-01-01

    The effectiveness of two treatment strategies (verbal prompts and a physical prompt) on the independent drinking skills of a 17-year-old girl with cortical visual impairment was investigated. Results found that the physical prompt was highly effective in promoting the target behavior, whereas verbal prompts were less effective. (Author/CR)

  17. Wave-function Visualization of Core-induced Interaction of Non-hydrogenic Rydberg Atom in Electric Field

    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...

  18. Fractionated irradiation of meningiomas of the optic nerve: the average ocular dose is a predictive factor of the visual function future

    As radiotherapy is efficient in terms of tumour growth control in the case of optic nerve meningiomas and allows a stabilization of visual acuity, but as radio-induced toxicity may threaten the functional benefit, the authors report a study which aimed at identifying predictive factors of a pejorative evolution of the visual function for patients submitted to radiotherapy for an optic nerve meningioma. Files of ten patients have been analyzed in terms clinical, radiological and dosimetric aspects. Visual acuity and visual field before and after conformational radiotherapy have been compared by means of the Wilcoxon Rank test. It appears that the visual function future can be threatened by irradiation side effects. Short communication

  19. Comparative study of visual functions in premature pre-school children with and without retinopathy of prematurity

    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.

  20. Visual and Artistic Functions of Letters in Khaghani’s Poetry

    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.

  1. Attenuation of functional hyperemia to visual stimulation in mild Alzheimer's disease and its sensitivity to cholinesterase inhibition.

    Janik, Rafal; Thomason, Lynsie A M; Chaudhary, Simone; Dorr, Adrienne; Scouten, Amy; Schwindt, Graeme; Masellis, Mario; Stanisz, Greg J; Black, Sandra E; Stefanovic, Bojana

    2016-05-01

    labeling MRI for quantitative evaluation of the brain vascular function in mild Alzheimer's disease. The findings provide evidence of a pronounced deficit in the visual cortex hyperemia despite the relative sparing of visual function in early stage AD, its reduction with ChEI treatment induction, and its stabilization in the first year of cholinesterase inhibition treatment. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock. PMID:26521151

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

    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 (organizational logic of cortical networks. PMID:27018655

  3. Visually directed pointing as a function of target distance, direction, and available cues.

    Foley, J. M.; Held, R.

    1972-01-01

    In pointing at visual targets without sight of the hand, large errors occur. There is a tendency to overreach targets, and this tendency is much greater (about 25 cm) when convergence is the only cue to distance than when there are many cues (2 to 11 cm). Angular errors of up to 10 deg also occur. These tend to be to the side opposite the sighting eye, when the favored hand is used. The variance of the pointing response with convergence alone is reduced by approximately half with the introduction of several spatial cues. These results are interpreted as indicating that, for a target within the reach of the arm and with convergence alone as a cue, the depth signal produced by the visual system corresponds to a greater distance than that produced when many cues are available. The results are also consistent with the hypothesis that perceived direction tends to approximate direction from the sighting eye.

  4. Effects of deuterium oxide and galvanic vestibular stimulation on visual cortical cell function

    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

  5. Effects of deuterium oxide and galvanic vestibular stimulation on visual cortical cell function

    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.

  6. Visual Evoked Potentials as a Readout of Cortical Function in Infants with Tuberous Sclerosis Complex

    Varcin, KJ; Nelson, CA; Ko, J.; Sahin, M.(Deutsches Elektronen-Synchrotron, Hamburg, Germany); Wu, JY; Jeste, SS

    2016-01-01

    © The Author(s) 2015. 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 whe...

  7. Teneurin-3 Specifies Morphological and Functional Connectivity of Retinal Ganglion Cells in the Vertebrate Visual System

    Paride Antinucci; Nikolas Nikolaou; Martin P. Meyer; Robert Hindges

    2013-01-01

    Summary A striking feature of the CNS is the precise wiring of its neuronal connections. During vertebrate visual system development, different subtypes of retinal ganglion cells (RGCs) form specific connections with their corresponding synaptic partners. However, the underlying molecular mechanisms remain to be fully elucidated. Here, we report that the cell-adhesive transmembrane protein Teneurin-3 (Tenm3) is required by zebrafish RGCs for acquisition of their correct morphological and func...

  8. Structural and functional organization of the visual system in the microphthalmic cave beetle Ptomaphagus hirtus

    Markus Friedrich; Elke K Buschbeck

    2013-01-01

    Strongly cave adapted animal species are invariably characterized by strong eye reduction (microphthalmy) to the complete loss of eyes (anophthalmy). Recent studies of cave adaptation have focused on the causes and mechanisms underlying the regressive evolution of the visual system but little attention has been paid to aspects of vision, which can remain conserved in the low-light level ecologies of caves. The small carrion beetle genus Ptomaphagus (Staphyliniformia: Leiodidae) includes both ...

  9. Basic multisensory functions can be acquired after congenital visual pattern deprivation in humans

    Putzar, L.; Gondan, Matthias; Röder, B.

    2012-01-01

    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....

  10. Development and Evaluation of Secure Socket Layer Visualization Tool with Packet Capturing Function

    Arai Masayuki

    2015-01-01

    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...

  11. What insights can fMRI offer into the structure and function of mid-tier visual areas?

    Olman, Cheryl A

    2015-01-01

    Inferring neural responses from functional magnetic resonance imaging (fMRI) data is challenging. Even if we take advantage of high-field systems to acquire data with submillimeter resolution, we are still acquiring data in which a single datum summarizes the responses of tens of thousands of neurons. Excitation and inhibition, spikes and subthreshold membrane potential modulations, local and long-range computations, and tuned and nonselective responses are mixed together in one signal. With a priori knowledge of the underlying neural population responses, careful experiment design allows us to manipulate the experiment or task design so that subpopulations are selectively modulated, and our experiments can reveal those tuning functions. However, because we want to be able to use fMRI to discover new kinds of tuning functions and selectivity, we cannot limit ourselves to experiments in which we already know what we are looking for. Broadly speaking, analyses that rely on classification of responses that are distributed across the local neural population [multi-voxel pattern analyses (MVPA)] offer the ability to discover new kinds of information representation and selectivities in neural subpopulations. There is, however, no way to determine how the information discovered with MVPA or other analyses is related to the underlying neuronal tuning functions. Therefore, we must continue to rely on behavioral, computational, and animal models to develop theories of information representation in mid-tier visual cortical areas. Once encoding models exist, fMRI can be powerful for testing these a priori models of information representation. As an aide in developing these models, an important contribution that fMRI can make to our understanding of mid-tier visual areas is derived from connectivity analyses and experiments that study information sharing between visual areas. This ability to quantify localized population average responses throughout the brain is the strength we

  12. New contributions in overcomplete image representations inspired from the functional architecture of the primary visual cortex = Nuevas contribuciones en representaciones sobrecompletas de imágenes inspiradas por la arquitectura funcional de la corteza visual primaria

    Fischer, Sylvain Gael Frederic

    2007-01-01

    The present thesis aims at investigating parallelisms between the functional architecture of primary visual areas and image processing methods. A first objective is to refine existing models of biological vision on the base of information theory statements and a second is to develop original solutions for image processing inspired from natural vision. The available data on visual systems contains physiological and psychophysical studies, Gestalt psychology and statistics on natural images The...

  13. Manipulation and visualization of two-dimensional phase distribution of vibrational wave functions in solid parahydrogen crystal

    Katsuki, Hiroyuki; Ohmori, Kenzo; Horie, Toru; Yanagi, Hisao; Ohmori, Kenji

    2015-09-01

    Solid parahydrogen, which is known to have an exceptionally long vibrational coherence lifetime as a molecular solid, offers an ideal testbed to perform coherent control experiments in the condensed phase. Here we demonstrate the spatial manipulation and visualization of the relative phase of vibrational wave functions in solid parahydrogen. Spatial distribution of vibrational excitation is generated by femtosecond impulsive Raman excitation. It is shown that the imprinted initial phase can be manipulated by wave-front modulation of the excitation laser pulses with a spatial light modulator. An interferometric measurement is used to convert the spatial phase distribution of the vibrational wave functions to the amplitude distribution. We have confirmed that the spatial profile of the scattered anti-Stokes pulse reveals the spatial phase distribution of the wave functions. The read-and-write scheme demonstrated in this experiment is applicable to a broad range of Raman memory systems accessible by Λ -type transitions.

  14. Exercise and physical training improve physical function in older adults with visual impairments but their effect on falls is unclear: a systematic review

    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

  15. 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

    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…

  16. A multi-stage model for fundamental functional properties in primary visual cortex.

    Nastaran Hesam Shariati

    Full Text Available Many neurons in mammalian primary visual cortex have properties such as sharp tuning for contour orientation, strong selectivity for motion direction, and insensitivity to stimulus polarity, that are not shared with their sub-cortical counterparts. Successful models have been developed for a number of these properties but in one case, direction selectivity, there is no consensus about underlying mechanisms. We here define a model that accounts for many of the empirical observations concerning direction selectivity. The model describes a single column of cat primary visual cortex and comprises a series of processing stages. Each neuron in the first cortical stage receives input from a small number of on-centre and off-centre relay cells in the lateral geniculate nucleus. Consistent with recent physiological evidence, the off-centre inputs to cortex precede the on-centre inputs by a small (∼4 ms interval, and it is this difference that confers direction selectivity on model neurons. We show that the resulting model successfully matches the following empirical data: the proportion of cells that are direction selective; tilted spatiotemporal receptive fields; phase advance in the response to a stationary contrast-reversing grating stepped across the receptive field. The model also accounts for several other fundamental properties. Receptive fields have elongated subregions, orientation selectivity is strong, and the distribution of orientation tuning bandwidth across neurons is similar to that seen in the laboratory. Finally, neurons in the first stage have properties corresponding to simple cells, and more complex-like cells emerge in later stages. The results therefore show that a simple feed-forward model can account for a number of the fundamental properties of primary visual cortex.

  17. Structure, Function and Input Pathways of Motion-sensitive Visual Interneurons in Drosophila melanogaster

    Schnell, Bettina

    2010-01-01

    Visual motion detection is of major importance for flies as they use the optic flow generated by their self-motion to control their course during flight. This so called optomotor behavior is thought to be controlled by a set of large-field motion-sensitive cells in the optic lobes called lobula plate tangential cells (LPTCs). LPTCs come in different variants and are tuned to different preferred directions. Their responses can be explained by assuming input from an array of local motion detect...

  18. Dynamic links between theta executive functions and alpha storage buffers in auditory and visual working memory

    Kawasaki, Masahiro(Institute for Cosmic Ray Research, the University of Tokyo, Chiba, 277-8582, Japan); Kitajo, Keiichi; Yamaguchi, Yoko

    2010-01-01

    Working memory (WM) tasks require not only distinct functions such as a storage buffer and central executive functions, but also coordination among these functions. Neuroimaging studies have revealed the contributions of different brain regions to different functional roles in WM tasks; however, little is known about the neural mechanism governing their coordination. Electroencephalographic (EEG) rhythms, especially theta and alpha, are known to appear over distributed brain regions during WM...

  19. Combination of blood oxygen level–dependent functional magnetic resonance imaging and visual evoked potential recordings for abnormal visual cortex in two types of amblyopia

    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

  20. Environmental enrichment extends photoreceptor survival and visual function in a mouse model of retinitis pigmentosa.

    Ilaria Barone

    Full Text Available Slow, progressive rod degeneration followed by cone death leading to blindness is the pathological signature of all forms of human retinitis pigmentosa (RP. Therapeutic schemes based on intraocular delivery of neuroprotective agents prolong the lifetime of photoreceptors and have reached the stage of clinical trial. The success of these approaches depends upon optimization of chronic supply and appropriate combination of factors. Environmental enrichment (EE, a novel neuroprotective strategy based on enhanced motor, sensory and social stimulation, has already been shown to exert beneficial effects in animal models of various disorders of the CNS, including Alzheimer and Huntington disease. Here we report the results of prolonged exposure of rd10 mice, a mutant strain undergoing progressive photoreceptor degeneration mimicking human RP, to such an enriched environment from birth. By means of microscopy of retinal tissue, electrophysiological recordings, visual behaviour assessment and molecular analysis, we show that EE considerably preserves retinal morphology and physiology as well as visual perception over time in rd10 mutant mice. We find that protective effects of EE are accompanied by increased expression of retinal mRNAs for CNTF and mTOR, both factors known as instrumental to photoreceptor survival. Compared to other rescue approaches used in similar animal models, EE is highly effective, minimally invasive and results into a long-lasting retinal protection. These results open novel perspectives of research pointing to environmental strategies as useful tools to extend photoreceptor survival.

  1. Functional asymmetry in sensory discrimination in visually blind and its association to braille reading

    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

  2. Functional architecture of visual emotion recognition ability: A latent variable approach.

    Lewis, Gary J; Lefevre, Carmen E; Young, Andrew W

    2016-05-01

    Emotion recognition has been a focus of considerable attention for several decades. However, despite this interest, the underlying structure of individual differences in emotion recognition ability has been largely overlooked and thus is poorly understood. For example, limited knowledge exists concerning whether recognition ability for one emotion (e.g., disgust) generalizes to other emotions (e.g., anger, fear). Furthermore, it is unclear whether emotion recognition ability generalizes across modalities, such that those who are good at recognizing emotions from the face, for example, are also good at identifying emotions from nonfacial cues (such as cues conveyed via the body). The primary goal of the current set of studies was to address these questions through establishing the structure of individual differences in visual emotion recognition ability. In three independent samples (Study 1: n = 640; Study 2: n = 389; Study 3: n = 303), we observed that the ability to recognize visually presented emotions is based on different sources of variation: a supramodal emotion-general factor, supramodal emotion-specific factors, and face- and within-modality emotion-specific factors. In addition, we found evidence that general intelligence and alexithymia were associated with supramodal emotion recognition ability. Autism-like traits, empathic concern, and alexithymia were independently associated with face-specific emotion recognition ability. These results (a) provide a platform for further individual differences research on emotion recognition ability, (b) indicate that differentiating levels within the architecture of emotion recognition ability is of high importance, and (c) show that the capacity to understand expressions of emotion in others is linked to broader affective and cognitive processes. (PsycINFO Database Record PMID:26986040

  3. Functional CT imaging: load-dependent visualization of the subchondral mineralization by means of CT osteoabsorptionmetry (CT-OAM)

    Purpose: Functional computed tomography for visualization and quantification of subchondral bone mineralization using CT osteoabsorptiometry (CT-OAM). Materials and Methods: Tarsometatarsal (TMT) and metatarsophalangeal (MTP) joints of 46 human hallux valgus (HV) specimens were examined (sagittal 1/1/1 mm) on a single slice CT scanner SCT (Somatom Plus 4, Siemens AG). Subchondral bone pixels were segmented and assigned to 10 density value groups (triangle 100 HU, range 200 - 1200 HU) the pixels using volume rendering technique (VRT). The data analysis considered the severity of HV as determined by the radiographically measured HV-angle (a.p. projection). Results: CT-OAM could generate reproducible densitograms of the distribution pattern of the subchondral bone density for all four joint surfaces (TMT and MTP joints). The bone density localization enables the assignment to different groups, showing a characteristic HV-angle-dependent distribution of the maximum bone mineralization of the load-dependent densitogram (p < 0.001). Conclusion: CT-OAM is a functional CT technique for visualizing and quantifying the distribution of the subchondral bone density, enabling a noninvasive load-dependent assessment of the joint surfaces. Load-dependent densitograms of hallux valgus specimens show a characteristic correlation with an increase of the HV-angle. (orig.)

  4. Resveratrol Based Oral Nutritional Supplement Produces Long-Term Beneficial Effects on Structure and Visual Function in Human Patients

    Stuart Richer

    2014-10-01

    Full Text Available Background: Longevinex® (L/RV is a low dose hormetic over-the-counter (OTC oral resveratrol (RV based matrix of red wine solids, vitamin D3 and inositol hexaphosphate (IP6 with established bioavailability, safety, and short-term efficacy against the earliest signs of human atherosclerosis, murine cardiac reperfusion injury, clinical retinal neovascularization, and stem cell survival. We previously reported our short-term findings for dry and wet age-related macular degeneration (AMD patients. Today we report long term (two to three year clinical efficacy. Methods: We treated three patients including a patient with an AMD treatment resistant variant (polypoidal retinal vasculature disease. We evaluated two clinical measures of ocular structure (fundus autofluorescent imaging and spectral domain optical coherence extended depth choroidal imaging and qualitatively appraised changes in macular pigment volume. We further evaluated three clinical measures of visual function (Snellen visual acuity, contrast sensitivity, and glare recovery to a cone photo-stress stimulus. Results: We observed broad bilateral improvements in ocular structure and function over a long time period, opposite to what might be expected due to aging and the natural progression of the patient’s pathophysiology. No side effects were observed. Conclusions: These three cases demonstrate that application of epigenetics has long-term efficacy against AMD retinal disease, when the retinal specialist has exhausted other therapeutic modalities.

  5. The functional foetal brain: A systematic preview of methodological factors in reporting foetal visual and auditory capacity

    Kirsty Dunn

    2015-06-01

    Full Text Available Due to technological advancements in functional brain imaging, foetal brain responses to visual and auditory stimuli is a growing area of research despite being relatively small with much variation between research laboratories. A number of inconsistencies between studies are, nonetheless, present in the literature. This article aims to explore the potential contribution of methodological factors to variation in reports of foetal neural responses to external stimuli. Some of the variation in reports can be explained by methodological differences in aspects of study design, such as brightness and wavelength of light source. In contrast to visual foetal processing, auditory foetal processing has been more frequently investigated and findings are more consistent between different studies. This is an early preview of an emerging field with many articles reporting small sample sizes with techniques that are yet to be replicated. We suggest areas for improvement for the field as a whole, such as the standardisation of stimulus delivery and a more detailed reporting of methods and results. This will improve our understanding of foetal functional response to light and sound. We suggest that enhanced technology will allow for a more reliable description of the developmental trajectory of foetal processing of light stimuli.

  6. Visual perception and visual cognition in healthy and pathological ageing

    MarkW.Greenlee; AllisonB.Sekuler

    2014-01-01

    Our understanding of visual perception and visual cognition has advanced considerably over the last decades. The effects of ageing on visual perception and visual cognition are less well understood. This Research Topic features state-of-the-art approaches to determining the effects of ageing on visual perception, visual attention, visual memory and visually guided behaviour. Studies using methods that incorporate psychophysics, eye movements, electrophysiology, structural and functional neuro...

  7. A prospective, contralateral comparison of photorefractive keratectomy (PRK versus thin-flap LASIK: assessment of visual function

    Hatch BB

    2011-04-01

    Full Text Available Bryndon B Hatch1, Majid Moshirfar1, Andrew J Ollerton1, Shameema Sikder2, Mark D Mifflin11John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USAPurpose: To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs in eyes with stable myopia undergoing either photorefractive keratectomy (PRK or thin-flap laser in situ keratomileusis (LASIK (intended flap thickness of 90 µm using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively.Methods: In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, contrast sensitivity, and complications.Results: At 6 months, mean values for UDVA (logMAR were -0.043 ± 0.668 and -0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466. UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600. Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156 or CDVA (P = 0.800 at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears.Conclusion: Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.Keywords: photorefractive keratectomy, thin-flap LASIK, visual

  8. Radionuclide Diuretic Renogram: Can Visual Interpretation of the Renal Parenchymal Transit Time and Split Renal Function Improves the Interpretation?

    Introduction: Obstructive Uropathy is a common clinical and surgical problem in many countries. The decision to intervene surgically versus medical treatment has to be supported by radiological, ultrasound, radionuclide, and urodynamic studies. Measurements of urodynamics by Whitaker test is an invasive procedure that also has limitations and requires expertise. The radionuclide diuretic renogram has many limitations and drawbacks. Unreliable results from the currently widely used programs are related to calculation of split renal function, lack of confidence in quantitative analysis of renal function parameters especially when there is retention of activity in the renal pelvis, timing of injection of Lasix, percentage of remaining functioning renal tissue, output of urine on affected side, size of the dilated pelvis and duration of obstruction. Inaccurate reports that do not reflect the true urodynamics of the obstructed kidneys and dilated renal pelvis especially after previous surgical corrections resulted in loss of confidence of the surgeons. Transit time measurements of the cortical, tubular, parenchymal and pelvis had been tried before and found to increase the accuracy of the interpretation. However, it requires complex deconvaluation analysis programs that had been clinically verified. Few institutions have access to these deconvaluation analysis programs. An alternative is visual measurement of the cortical tubular and parenchymal transit time from the diuretic renograms images, which is the subject of this presentation and the aim of a retrospective analysis of the diuretic renograms performed at St. Vincent's Medical Center, Manhattan, New York from September 2005 through December 2008. This is part of an ongoing analysis. Materials and Methods: Radionuclide renogram studies of 204 patients who underwent 253 studies with suspected obstructive uropathy (OU) were reviewed. 49 patients had repeated studies, 19 had non-functioning kidneys that were excluded

  9. Failure to visualize acutely injured kidneys with technetium-99m DMSA does not preclude recoverable function

    A 35-yr-old patient developed severe acute tubular necrosis requiring hemodialysis. A [99mTc]dimercaptosuccinic acid scan of the kidneys showed no renal uptake at 4 or 24 hr, but the patient subsequently recovered normal renal function as judged by a normal serum creatinine. Based on this case report and a review of the literature, one cannot assume irreversible loss of function in patients with acute renal failure, based on the absence of radiopharmaceutical uptake by the kidneys

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

    Statiev S. I.

    2010-01-01

    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 measur...

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

    Cromwell, Ronita L.

    2011-01-01

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

  12. Functional anatomy and interaction of fast and slow visual pathways in macaque monkeys.

    Chen, Chi-Ming; Lakatos, Peter; Shah, Ankoor S; Mehta, Ashesh D; Givre, Syndee J; Javitt, Daniel C; Schroeder, Charles E

    2007-07-01

    We measured the timing, areal distribution, and laminar profile of fast, wavelength-insensitive and slower, wavelength-sensitive responses in V1 and extrastriate areas, using laminar current-source density analysis in awake macaque monkeys. There were 3 main findings. 1) We confirmed previously reported significant ventral-dorsal stream latency lags at the level of V4 (V4 mean = 38.7 ms vs. middle temporal mean = 26.9 ms) and inferotemporal cortex (IT mean = 43.4 ms vs. dorsal bank of the superior temporal sulcus mean = 33.9 ms). 2) We found that wavelength-sensitive inputs in areas V1, V4, and IT lagged the wavelength-insensitive responses by significant margins; this lag increased over successive levels of the system. 3) We found that laminar activation profiles in V4 and IT were inconsistent with "feedforward" input through the ascending ventral cortical pathway; the likely alternative input routes include both lateral inputs from the dorsal stream and direct inputs from nonspecific thalamic neurons. These findings support a "Framing" Model of ventral stream visual processing in which rapidly conducted inputs, mediated by one or more accessory pathways, modulate the processing of more slowly conducted feedforward inputs. PMID:16950866

  13. Pharmacological and rAAV gene therapy rescue of visual functions in a blind mouse model of Leber congenital amaurosis.

    2005-11-01

    Full Text Available BACKGROUND: Leber congenital amaurosis (LCA, a heterogeneous early-onset retinal dystrophy, accounts for approximately 15% of inherited congenital blindness. One cause of LCA is loss of the enzyme lecithin:retinol acyl transferase (LRAT, which is required for regeneration of the visual photopigment in the retina. METHODS AND FINDINGS: An animal model of LCA, the Lrat-/- mouse, recapitulates clinical features of the human disease. Here, we report that two interventions--intraocular gene therapy and oral pharmacologic treatment with novel retinoid compounds--each restore retinal function to Lrat-/- mice. Gene therapy using intraocular injection of recombinant adeno-associated virus carrying the Lrat gene successfully restored electroretinographic responses to approximately 50% of wild-type levels (p < 0.05 versus wild-type and knockout controls, and pupillary light responses (PLRs of Lrat-/- mice increased approximately 2.5 log units (p < 0.05. Pharmacological intervention with orally administered pro-drugs 9-cis-retinyl acetate and 9-cis-retinyl succinate (which chemically bypass the LRAT-catalyzed step in chromophore regeneration also caused long-lasting restoration of retinal function in LRAT-deficient mice and increased ERG response from approximately 5% of wild-type levels in Lrat-/- mice to approximately 50% of wild-type levels in treated Lrat-/- mice (p < 0.05 versus wild-type and knockout controls. The interventions produced markedly increased levels of visual pigment from undetectable levels to 600 pmoles per eye in retinoid treated mice, and approximately 1,000-fold improvements in PLR and electroretinogram sensitivity. The techniques were complementary when combined. CONCLUSION: Intraocular gene therapy and pharmacologic bypass provide highly effective and complementary means for restoring retinal function in this animal model of human hereditary blindness. These complementary methods offer hope of developing treatment to restore vision

  14. Subcortical BOLD responses during visual sexual stimulation vary as a function of implicit porn associations in women.

    Borg, Charmaine; de Jong, Peter J; Georgiadis, Janniko R

    2014-02-01

    Lifetime experiences shape people's attitudes toward sexual stimuli. Visual sexual stimulation (VSS), for instance, may be perceived as pleasurable by some, but as disgusting or ambiguous by others. VSS depicting explicit penile-vaginal penetration (PEN) is relevant in this respect, because the act of penetration is a core sexual activity. In this study, 20 women without sexual complaints participated. We used functional magnetic resonance imaging and a single-target implicit association task to investigate how brain responses to PEN were modulated by the initial associations in memory (PEN-'hot' vs PEN-disgust) with such hardcore pornographic stimuli. Many brain areas responded to PEN in the same way they responded to disgust stimuli, and PEN-induced brain activity was prone to modulation by subjective disgust ratings toward PEN stimuli. The relative implicit PEN-disgust (relative to PEN-'hot') associations exclusively modulated PEN-induced brain responses: comparatively negative (PEN-disgust) implicit associations with pornography predicted the strongest PEN-related responses in the basal forebrain (including nucleus accumbens and bed nucleus of stria terminalis), midbrain and amygdala. Since these areas are often implicated in visual sexual processing, the present findings should be taken as a warning: apparently their involvement may also indicate a negative or ambivalent attitude toward sexual stimuli. PMID:23051899

  15. Visual Pattern Memory Requires "Foraging" Function in the Central Complex of "Drosophila"

    Wang, Zhipeng; Pan, Yufeng; Li, Weizhe; Jiang, Huoqing; Chatzimanolis, Lazaros; Chang, Jianhong; Gong, Zhefeng; Liu, Li

    2008-01-01

    The role of the "foraging" ("for)" gene, which encodes a cyclic guanosine-3',5'-monophosphate (cGMP)-dependent protein kinase (PKG), in food-search behavior in "Drosophila" has been intensively studied. However, its functions in other complex behaviors have not been well-characterized. Here, we show experimentally in "Drosophila" that the "for"…

  16. Three-Dimensional Visualization of Wave Functions for Rotating Molecule: Plot of Spherical Harmonics

    Nagaoka, Shin-ichi; Teramae, Hiroyuki; Nagashima, Umpei

    2013-01-01

    At an early stage of learning quantum chemistry, undergraduate students usually encounter the concepts of the particle in a box, the harmonic oscillator, and then the particle on a sphere. Rotational levels of a diatomic molecule can be well approximated by the energy levels of the particle on a sphere. Wave functions for the particle in a…

  17. Left Brain vs. Right Brain: Findings on Visual Spatial Capacities and the Functional Neurology of Giftedness

    Kalbfleisch, M. Layne; Gillmarten, Charles

    2013-01-01

    As neuroimaging technologies increase their sensitivity to assess the function of the human brain and results from these studies draw the attention of educators, it becomes paramount to identify misconceptions about what these data illustrate and how these findings might be applied to educational contexts. Some of these "neuromyths" have…

  18. Restoration of visual function by expression of a light-gated mammalian ion channel in retinal ganglion cells or ON-bipolar cells

    Gaub, Benjamin M.; Berry, Michael H.; Holt, Amy E.; Reiner, Andreas; Kienzler, Michael A; Dolgova, Natalia; Nikonov, Sergei; Aguirre, Gustavo D.; Beltran, William A.; Flannery, John G.; Isacoff, Ehud Y.

    2014-01-01

    We restored visual function to animal models of human blindness using a chemical compound that photosensitizes a mammalian ion channel. Virus-mediated expression of this light sensor in surviving retinal cells of blind mice restored light responses in vitro, reanimated innate light avoidance, and enabled learned visually guided behavior. The treatment also restored light responses to the retina of blind dogs. Patients that might benefit from this treatment would need to have intact ganglion c...

  19. Brain Activation in Response to Visually Evoked Sexual Arousal in Male-to-Female Transsexuals: 3.0 Tesla Functional Magnetic Resonance Imaging

    Oh, Seok-Kyun; Kim, Gwang-Won; Yang, Jong-Chul; Kim, Seok-Kwun; Kang, Heoung-Keun; Jeong, Gwang-Woo

    2012-01-01

    Objective This study used functional magnetic resonance imaging (fMRI) to contrast the differential brain activation patterns in response to visual stimulation with both male and female erotic nude pictures in male-to-female (MTF) transsexuals who underwent a sex reassignment surgery. Materials and Methods A total of nine healthy MTF transsexuals after a sex reassignment surgery underwent fMRI on a 3.0 Tesla MR Scanner. The brain activation patterns were induced by visual stimulation with bot...

  20. Fourier-domain optical coherence tomography of eyes with idiopathic epiretinal membrane: correlation between macular morphology and visual function

    Pilli, S; Lim, P; Zawadzki, R J; Choi, S S; Werner, J S; Park, S S

    2011-01-01

    Purpose The purpose of this study is to evaluate the macular morphological changes associated with idiopathic epiretinal membrane (iERM) using high-resolution Fourier-domain optical coherence tomography (FD-OCT), as they correlate with visual acuity and microperimetry (MP-1). Methods In all, 24 eyes (19 subjects) with iERM were imaged prospectively using FD-OCT with axial resolution of 4.5 μm and transverse resolution of 10 to 15 μm. MP-1 and Stratus OCT were carried out in a subset of eyes. Results The mean log of the minimum angle of resolution best-corrected visual acuity (BCVA) was 0.18±0.16 (range: −0.08 to 0.48, Snellen equivalent 20/15−1 to 20/60). ERM was visualized in all 24 eyes with FD-OCT and in 17 eyes (85%) of 20 eyes imaged with Stratus OCT. Although BCVA correlated with macular thickening in the central 1 mm sub-field of the Stratus ETDRS (P=0.0005) and macular volume (central 3 mm area) on FD-OCT (P<0.0001), macular thickening on thickness map and volume correlated poorly with decrease in macular sensitivity on MP-1 (P=0.16). On FD-OCT, foveal morphological changes correlated best with decrease in BCVA, the strongest being central foveal thickness (P<0.0001). Other significant changes included blurring of the foveal inner segment–outer segment (IS–OS) junction and/or Verhoeff's membrane, vitreal displacement of foveal outer nuclear layer and foveal detachment (P<0.05). Foveal IS–OS junction disruption was seen in 25% of eyes on Stratus OCT but in none of the eyes on FD-OCT. Conclusion FD-OCT allowed improved visualization of ERM and associated foveal morphological changes that correlated best with BCVA. Macular thickening correlated weakly with decreased macular function as assessed by MP-1. PMID:21436847

  1. Discovery and visualization of miRNA-mRNA functional modules within integrated data using bicluster analysis.

    Bryan, Kenneth; Terrile, Marta; Bray, Isabella M; Domingo-Fernandéz, Raquel; Watters, Karen M; Koster, Jan; Versteeg, Rogier; Stallings, Raymond L

    2014-02-01

    MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression at a post-transcriptional level. An miRNA may target many messenger RNA (mRNA) transcripts, and each transcript may be targeted by multiple miRNAs. Our understanding of miRNA regulation is evolving to consider modules of miRNAs that regulate groups of functionally related mRNAs. Here we expand the model of miRNA functional modules and use it to guide the integration of miRNA and mRNA expression and target prediction data. We present evidence of cooperativity between miRNA classes within this integrated miRNA-mRNA association matrix. We then apply bicluster analysis to uncover miRNA functional modules within this integrated data set and develop a novel application to visualize and query these results. We show that this wholly unsupervised approach can discover a network of miRNA-mRNA modules that are enriched for both biological processes and miRNA classes. We apply this method to investigate the interplay of miRNAs and mRNAs in integrated data sets derived from neuroblastoma and human immune cells. This study is the first to apply the technique of biclustering to model functional modules within an integrated miRNA-mRNA association matrix. Results provide evidence of an extensive modular miRNA functional network and enable characterization of miRNA function and dysregulation in disease. PMID:24357407

  2. Diode Laser 810 Nm as a Potential Treatment to Improve Visual Function in Nonarteritic Anterior Ischemic Optic Neuropathy (NAION

    Mohammad Hossein Heidari

    2011-01-01

    Full Text Available Nonarteritic anterior ischemic optic neuropathy (NAION is one of the most widespread visually disabling diseases in the middle-aged and elderly population. The optic nerve damage appears to result from a perfusion insufficiency in the short posterior ciliary arteries leading to infarction of the retrolaminar portion of the optic disc. Induced Heat shock protein (Hsp is known to have neuroprotective effects against ischemic injury of the central nervous system in mammals. Transpupillary thermotherapy (TTT application to the optic nerve head induces Hsp70 expression. We hypothesize that Transpupillary thermotherapy (TTT could be a novel method for improving and preserving the function of the optic nerve fibers in the eye with NAION. An 810-nm diode laser beam is focused to the center of the optic nerve head to induce Hsp. Controlled prospective and randomized clinical trial is necessary to confirm conclusively the effectiveness of this method.

  3. Restoration of pretrabeculectomy visual acuity and a functioning filtering bleb in an eye with delayed suprachoroidal haemorrhage following trabeculectomy.

    Senthil, Sirisha; Gupta, Supriya; Balijepalli, Pasyanthi

    2015-01-01

    A 35-year-old myopic man with juvenile open angle glaucoma was referred to us with fluctuating intraocular pressure (IOP) and progression in his only seeing left eye. He had systemic features suggestive of Marfan's syndrome. He underwent trabeculectomy with low dose mitomycin-C with operative precautions to prevent postoperative hypotony in view of high myopia and scleral thinning. On the second postoperative day, he had severe pain in his left eye, with vomiting, and presented with decreased vision, high IOP and a flat anterior chamber. Ultrasound B scan revealed 360° haemorrhagic choroidal detachment. He was conservatively managed and monitored over the next 1 month with appropriate medical treatment. He not only recovered his pretrabeculectomy visual acuity but also had a well functioning bleb at the end of 2 months. PMID:26661281

  4. Geometric modeling, functional parameter calculation, and visualization of the in-vivo distended rectal wall

    Haider, Clifton R.; Manduca, Armando; Camp, Jon J.; Fletcher, Joel G.; Robb, Richard A.; Bharucha, Adil E.

    2006-03-01

    The rectum can distend to accommodate stool, and contracts in response to distention during defecation. Rectal motor dysfunctions are implicated in the pathophysiology of functional defecation disorders and fecal incontinence. These rectal motor functions can be studied by intra-luminal measurements of pressure by manometry, or combined with volume during rectal balloon distention. Pressure-volume (p-v) relationships provide a global index of rectal mechanical properties. However, balloon distention alone does not measure luminal radius or wall thickness, which are necessary to compute wall tension and stress respectively. It has been suggested that the elastic modulus, which is the linear slope of the stress-strain relationship, is a more accurate measure of wall stiffness. Also, measurements of compliance may not reflect differences in rectal diameter between subjects prior to inflation, and imaging is necessary to determine if, as has been suggested, rectal pressure-volume relationships are affected by extra-rectal structures. We have developed a technique to measure rectal stress:strain relationships in humans, by simultaneous magnetic resonance imaging (MRI) during rectal balloon distention. After a conditioning distention, a rectal balloon was distended with water from 0 to 400 ml in 50 ml steps, and imaged at each step with MRI. The fluid filled balloon was segmented from each volume, the phase-ordered binary volumes were transformed into a geometric characterization of the inflated rectal surface. Taken together with measurements of balloon pressure and of rectal wall thickness, this model of the rectal surface was used to calculate regional values of curvature, tension, strain, and stress for the rectum. In summary, this technique has the unique ability to non-invasively measure the rectal stress:strain relationship and also determine if rectal expansion is limited by extra-rectal structures. This functional information allows the direct clinical analysis

  5. Fluorescent Lipids: Functional Parts of Fusogenic Liposomes and Tools for Cell Membrane Labeling and Visualization

    Christian Kleusch; Bernd Hoffmann; Nils Hersch; Agnes Csiszár; Rudolf Merkel

    2012-01-01

    In this paper a rapid and highly efficient method for controlled incorporation of fluorescent lipids into living mammalian cells is introduced. Here, the fluorescent molecules have two consecutive functions: First, they trigger rapid membrane fusion between cellular plasma membranes and the lipid bilayers of their carrier particles, so called fusogenic liposomes, and second, after insertion into cellular membranes these molecules enable fluorescence imaging of cell membranes and membrane traf...

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

    Takao Shimomura; Quan Liang Chen

    2009-01-01

    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 w...

  7. Altered visual function and interneuron survival in Atrx knockout mice: inference for the human syndrome.

    Medina, Chantal F; Mazerolle, Chantal; Wang, Yaping; Bérubé, Nathalie G; Coupland, Stuart; Gibbons, Richard J; Wallace, Valerie A; Picketts, David J

    2009-03-01

    ATRX is an SWI/SNF-like chromatin remodeling protein that is mutated in several X-linked mental retardation syndromes, including the ATR-X syndrome. In mice, Atrx expression is widespread and attempts to understand its function in brain development are hampered by the lethality associated with ubiquitous or forebrain-restricted ablation of this gene. One way to circumvent this problem is to study its function in a region of the brain that is dispensable for long-term survival of the organism. The retina is a well-characterized tractable model of CNS development and in our review of 202 ATR-X syndrome patients, we found ocular defects present in approximately 25% of the cases, suggesting that studying Atrx in this tissue will provide insight into function. We report that Atrx is expressed in the neuroprogenitor pool in embryonic retina and in all cell types of the mature retina with the exception of rod photoreceptors. Conditional inactivation of Atrx in the retina during embryogenesis ultimately results in a loss of only two types of neurons, amacrine and horizontal cells. We show that this defect does not arise from a failure to specify these cells but rather a defect in interneuron differentiation and survival post-natally. The timing of cell loss is concomitant with light-dependent changes in synaptic organization in the retina and with a change in Atrx subnuclear localization within these interneurons. Moreover, these interneuron defects are associated with functional deficits as demonstrated by reduced b-wave amplitudes upon electroretinogram analysis. These results implicate a role for Atrx in interneuron survival and differentiation. PMID:19088125

  8. Event-related Single-shot Volumetric Functional Magnetic Resonance Inverse Imaging of Visual Processing

    Lin, Fa-Hsuan; Witzel, Thomas; Mandeville, Joseph B.; Polimeni, Jonathan R; Zeffiro, Thomas A.; Greve, Douglas N.; Wiggins, Graham; Wald, Lawrence L.; Belliveau, John W.

    2008-01-01

    Developments in multi-channel radio-frequency (RF) coil array technology have enabled functional magnetic resonance imaging (fMRI) with higher degrees of spatial and temporal resolution. While modest improvement in temporal acceleration has been achieved by increasing the number of RF coils, in parallel data acquisition techniques, the maximum attainable acceleration is intrinsically limited only by the amount of independent spatial information in the combined array channels. Since the geomet...

  9. Visualization of a particle's wave function in the double slits experiment

    Postnikov, Eugene B

    2013-01-01

    The double slits experiment is a basic phenomenon, which allows to explain principal behaviour of quantum systems. However, textbooks present static pictures of corresponding interference patterns. At the same time, modern computer software for PDE solution provides an opportunity for dynamical modeling of a wave function behaviour using a numerical solution of Schroedinger's equation and to use the obtained demonstrations in a teaching of physics. This material presents such a dynamical animated simulation.

  10. Autistic fluid intelligence: Increased reliance on visual functional connectivity with diminished modulation of coupling by task difficulty

    Isabelle Simard

    2015-01-01

    Full Text Available Different test types lead to different intelligence estimates in autism, as illustrated by the fact that autistic individuals obtain higher scores on the Raven's Progressive Matrices (RSPM test than they do on the Wechsler IQ, in contrast to relatively similar performance on both tests in non-autistic individuals. However, the cerebral processes underlying these differences are not well understood. This study investigated whether activity in the fluid “reasoning” network, which includes frontal, parietal, temporal and occipital regions, is differently modulated by task complexity in autistic and non-autistic individuals during the RSPM. In this purpose, we used fMRI to study autistic and non-autistic participants solving the 60 RSPM problems focussing on regions and networks involved in reasoning complexity. As complexity increased, activity in the left superior occipital gyrus and the left middle occipital gyrus increased for autistic participants, whereas non-autistic participants showed increased activity in the left middle frontal gyrus and bilateral precuneus. Using psychophysiological interaction analyses (PPI, we then verified in which regions did functional connectivity increase as a function of reasoning complexity. PPI analyses revealed greater connectivity in autistic, compared to non-autistic participants, between the left inferior occipital gyrus and areas in the left superior frontal gyrus, right superior parietal lobe, right middle occipital gyrus and right inferior temporal gyrus. We also observed generally less modulation of the reasoning network as complexity increased in autistic participants. These results suggest that autistic individuals, when confronted with increasing task complexity, rely mainly on visuospatial processes when solving more complex matrices. In addition to the now well-established enhanced activity observed in visual areas in a range of tasks, these results suggest that the enhanced reliance on visual

  11. Bivariate mass-size relation as a function of morphology as determined by Galaxy Zoo 2 crowdsourced visual classifications

    Beck, Melanie; Scarlata, Claudia; Fortson, Lucy; Willett, Kyle; Galloway, Melanie

    2016-01-01

    It is well known that the mass-size distribution evolves as a function of cosmic time and that this evolution is different between passive and star-forming galaxy populations. However, the devil is in the details and the precise evolution is still a matter of debate since this requires careful comparison between similar galaxy populations over cosmic time while simultaneously taking into account changes in image resolution, rest-frame wavelength, and surface brightness dimming in addition to properly selecting representative morphological samples.Here we present the first step in an ambitious undertaking to calculate the bivariate mass-size distribution as a function of time and morphology. We begin with a large sample (~3 x 105) of SDSS galaxies at z ~ 0.1. Morphologies for this sample have been determined by Galaxy Zoo crowdsourced visual classifications and we split the sample not only by disk- and bulge-dominated galaxies but also in finer morphology bins such as bulge strength. Bivariate distribution functions are the only way to properly account for biases and selection effects. In particular, we quantify the mass-size distribution with a version of the parametric Maximum Likelihood estimator which has been modified to account for measurement errors as well as upper limits on galaxy sizes.

  12. Visualization of the functional recovery process of brain and spinal cord after injury

    Elucidation of the process of spontaneous functional recovery of central nervous system (CNS) after injury like trauma and stroke is important to develop and conduct the better rehabilitation training to promote the recuperation. Authors have developed a macaque monkey model with an artificial injury of cervical corticospinal tract (CST), where its elaborative motor activity of fingers spontaneously recovers. This paper describes the selective CST injury procedure, its recovery process in finger movement and in CNS images by positron emission tomography (PET), and validation of the obtained images by nerve block. For the injury, CST is cut selectively at monkey's C4/C5 boundary to block the hand motion nerve and to preserve the 2-synapse pathway through the propriospinal neuron, which results in acute loss of grasping a piece of potato food. At 1-3 months after the treatment, the elaborative motor activity of fingers completely recovers. During this recovery period, PET is conducted to trace the brain blood flow change at the upper center of the motion in realizing/grasping food, where the dorsal pathway and cerebellar nuclei are activated at the motion in the untreated animal. At 1-2 months after operation, the blood flow is found increased in the two areas above and the increased area, widened relative to those before operation. At 3 months (at complete functional recovery), the activity in the ipsilateral primary motor area returns to normal level and in the contralateral area, is spread accompanying the increase in the bilateral dorsal premotor and secondary somatosensory areas. Imaging results are validated by nerve block with micro-injection of muscimol into the activated areas during the task motor. Findings are helpful for developing a method to promote the compensation of nervous function after injury. (K.T.)

  13. TreeQ-VISTA: An Interactive Tree Visualization Tool withFunctional Annotation Query Capabilities

    Gu, Shengyin; Anderson, Iain; Kunin, Victor; Cipriano, Michael; Minovitsky, Simon; Weber, Gunther; Amenta, Nina; Hamann, Bernd; Dubchak,Inna

    2007-05-07

    Summary: We describe a general multiplatform exploratorytool called TreeQ-Vista, designed for presenting functional annotationsin a phylogenetic context. Traits, such as phenotypic and genomicproperties, are interactively queried from a relational database with auser-friendly interface which provides a set of tools for users with orwithout SQL knowledge. The query results are projected onto aphylogenetic tree and can be displayed in multiple color groups. A richset of browsing, grouping and query tools are provided to facilitatetrait exploration, comparison and analysis.Availability: The program,detailed tutorial and examples are available online athttp://genome-test.lbl.gov/vista/TreeQVista.

  14. An integrated multi-functional neutronics calculation and analysis code system: VisualBUS

    Neutronics calculation and analysis are the bases of reactor physics design, radiation protection, fuel management optimization, nuclear safety analysis, etc. After surveying and evaluating the status and trend of development of neutronics calculation and analysis codes, a network-based integrated multi-functional neutronics calculation and analysis code system has been designed and developed for applications in fusion, fission and various hybrid systems based on the adoption of advanced neutronics calculating approaches and modern computer' software technologies. A series of benchmark tests and applications have shown the maturity and effectiveness of the system. This paper gives a brief overview about main technical features of the system, the benchmark tests and applications. (authors)

  15. Fluorescent Lipids: Functional Parts of Fusogenic Liposomes and Tools for Cell Membrane Labeling and Visualization

    Christian Kleusch

    2012-01-01

    Full Text Available In this paper a rapid and highly efficient method for controlled incorporation of fluorescent lipids into living mammalian cells is introduced. Here, the fluorescent molecules have two consecutive functions: First, they trigger rapid membrane fusion between cellular plasma membranes and the lipid bilayers of their carrier particles, so called fusogenic liposomes, and second, after insertion into cellular membranes these molecules enable fluorescence imaging of cell membranes and membrane traffic processes. We tested the fluorescent derivatives of the following essential membrane lipids for membrane fusion: Ceramide, sphingomyelin, phosphocholine, phosphatidylinositol-bisphosphate, ganglioside, cholesterol, and cholesteryl ester. Our results show that all probed lipids could more efficiently be incorporated into the plasma membrane of living cells than by using other methods. Moreover, labeling occurred in a gentle manner under classical cell culture conditions reducing cellular stress responses. Staining procedures were monitored by fluorescence microscopy and it was observed that sphingolipids and cholesterol containing free hydroxyl groups exhibit a decreased distribution velocity as well as a longer persistence in the plasma membrane compared to lipids without hydroxyl groups like phospholipids or other artificial lipid analogs. After membrane staining, the fluorescent molecules were sorted into membranes of cell organelles according to their chemical properties and biological functions without any influence of the delivery system.

  16. Blue cone monochromacy: visual function and efficacy outcome measures for clinical trials.

    Xunda Luo

    Full Text Available Blue Cone Monochromacy (BCM is an X-linked retinopathy caused by mutations in the OPN1LW / OPN1MW gene cluster, encoding long (L- and middle (M-wavelength sensitive cone opsins. Recent evidence shows sufficient structural integrity of cone photoreceptors in BCM to warrant consideration of a gene therapy approach to the disease. In the present study, the vision in BCM is examined, specifically seeking clinically-feasible outcomes for a future clinical trial.BCM patients (n = 25, ages 5-72 were studied with kinetic and static chromatic perimetry, full-field sensitivity testing, and eye movement recordings. Vision at the fovea and parafovea was probed with chromatic microperimetry.Kinetic fields with a Goldmann size V target were generally full. Short-wavelength (S- sensitive cone function was normal or near normal in most patients. Light-adapted perimetry results on conventional background lights were abnormally reduced; 600-nm stimuli were seen by rods whereas white stimuli were seen by both rods and S-cones. Under dark-adapted conditions, 500-nm stimuli were seen by rods in both BCM and normals. Spectral sensitivity functions in the superior retina showed retained rod and S-cone functions in BCM under dark-adapted and light-adapted conditions. In the fovea, normal subjects showed L/M-cone mediation using a 650-nm stimulus under dark-adapted conditions, whereas BCM patients had reduced sensitivity driven by rod vision. Full-field red stimuli on bright blue backgrounds were seen by L/M-cones in normal subjects whereas BCM patients had abnormally reduced and rod-mediated sensitivities. Fixation location could vary from fovea to parafovea. Chromatic microperimetry demonstrated a large loss of sensitivity to red stimuli presented on a cyan adapting background at the anatomical fovea and surrounding parafovea.BCM rods continue to signal vision under conditions normally associated with daylight vision. Localized and retina-wide outcome measures were

  17. Visualization and analysis of occlusion for human jaws using a "functionally generated path"

    Myszkowski, Karol; Herder, Jens; Kunii, Tosiyasu L.; Ibusuki, Masumi

    1996-03-01

    Dynamic characteristics of occlusion during lower jaw motion are useful in the diagnosis of jaw articulation problems and in computer-aided design/ manufacture of teeth restorations. The Functionally Generated Path (FGP), produced as a surface which envelops the actual occlusal surface of the moving opponent jaw, can be used for compact representation of dynamic occlusal relations. In traditional dentistry FGP is recorded as a bite impression in a patient's mouth. We propose an efficient computerized technique for FGP reconstruction and validate it through implementation and testing. The distance maps between occlusal surfaces of jaws, calculated for multiple projection directions and accumulated for mandibular motion, provide information for FGP computation. Rasterizing graphics hardware is used for fast calculation of the distance maps. Real-world data are used: the scanned shape of teeth and the measured motion of the lower jaw. We show applications of FGP to analysis of the occlusion relations and occlusal surface design for restorations.

  18. Clinical comparison of three techniques for evaluating visual function behind cataract.

    Barrett, B T; Davison, P A; Eustace, P

    1995-01-01

    The aim of the study was to compare the ability of displacement threshold hyperacuity to identify reduced retinal/neural function in cataract patients with that of the potential acuity meter (PAM) and laser interferometer. Fifty-two patients (mean age 72.0 +/- 10.8 years) admitted for extracapsular cataract extraction were randomly selected for inclusion in the study. Patients underwent routine refraction and logMAR acuity measurement on the eve of cataract surgery. Following pupillary dilation and in random order, the oscillatory displacement threshold (ODT; defined as the smallest detectable displacement of an object) was determined, and predictions of the post-operative acuity were obtained using the PAM and Rodenstock Retinometer (RR). Patients were re-examined approximately 7 weeks post-operatively when logMAR acuities and ODTs were remeasured. On the basis of the results of an independent fundus examination, patients were assigned to either a normal or a pathology group. Increasing cataract density adversely affected the predictions provided by the PAM (p = 0.0001) and ODT (p = 0.0001) techniques, but not the RR (p = 0.137). One-factor ANOVA revealed that pre-operative ODT (p = 0.0001), PAM (p = 0.0001) and RR (p = 0.0004) measures successfully distinguished patients with retinal/neural pathology from normals. Pre-operative cut-off levels to distinguish normal from pathology cases were retrospectively determined for each technique. The cut-off values for the PAM and ODT techniques yielded higher sensitivity and specificity values than was the case for the RR. The results suggest that the predictive abilities of the PAM and ODT techniques are similar, and superior to that of the RR. Further work involving larger numbers of patients with posterior segment pathology is necessary to reveal which technique provides the best means of assessing retinal/neural function in the presence of ocular media opacities. PMID:8849539

  19. Mulan: Multiple-Sequence Local Alignment and Visualization for Studying Function and Evolution

    Ovcharenko, I; Loots, G; Giardine, B; Hou, M; Ma, J; Hardison, R; Stubbs, L; Miller, W

    2004-07-14

    Multiple sequence alignment analysis is a powerful approach for understanding phylogenetic relationships, annotating genes and detecting functional regulatory elements. With a growing number of partly or fully sequenced vertebrate genomes, effective tools for performing multiple comparisons are required to accurately and efficiently assist biological discoveries. Here we introduce Mulan (http://mulan.dcode.org/), a novel method and a network server for comparing multiple draft and finished-quality sequences to identify functional elements conserved over evolutionary time. Mulan brings together several novel algorithms: the tba multi-aligner program for rapid identification of local sequence conservation and the multiTF program for detecting evolutionarily conserved transcription factor binding sites in multiple alignments. In addition, Mulan supports two-way communication with the GALA database; alignments of multiple species dynamically generated in GALA can be viewed in Mulan, and conserved transcription factor binding sites identified with Mulan/multiTF can be integrated and overlaid with extensive genome annotation data using GALA. Local multiple alignments computed by Mulan ensure reliable representation of short-and large-scale genomic rearrangements in distant organisms. Mulan allows for interactive modification of critical conservation parameters to differentially predict conserved regions in comparisons of both closely and distantly related species. We illustrate the uses and applications of the Mulan tool through multi-species comparisons of the GATA3 gene locus and the identification of elements that are conserved differently in avians than in other genomes allowing speculation on the evolution of birds. Source code for the aligners and the aligner-evaluation software can be freely downloaded from http://bio.cse.psu.edu/.

  20. Many Paths to a Common Destination: Morphological Differentiation of a Functionally Convergent Visual Signal.

    Hagman, Mattias; Ord, Terry J

    2016-09-01

    Understanding the interacting outcomes of selection and historical contingency in shaping adaptive evolution remains a challenge in evolutionary biology. While selection can produce convergent outcomes when species occupy similar environments, the unique history of each species can also influence evolutionary trajectories and result in different phenotypic end points. The question is to what extent historical contingency places species on different adaptive pathways and, in turn, the extent to which we can predict evolutionary outcomes. Among lizards there are several distantly related genera that have independently evolved an elaborate extendible dewlap for territorial communication. We conducted a detailed morphological study and employed new phylogenetic comparative methods to investigate the evolution of the underlying hyoid that powers the extension of the dewlap. This analysis showed that there appear to have been multiple phenotypic pathways for evolving a functionally convergent dewlap. The biomechanical complexity that underlies this morphological structure implies that adaptation should have been constrained to a narrow phenotypic pathway. However, multiple adaptive solutions have been possible in apparent response to a common selection pressure. Thus, the phenotypic outcome that subsequently evolved in different genera seems to have been contingent on the history of the group in question. This blurs the distinction between convergent and historically contingent adaptation and suggests that adaptive phenotypic diversity can evolve without the need for divergent natural selection. PMID:27501088

  1. Spectral Tuning of Killer Whale (Orcinus orca) Rhodopsin: Evidence for Positive Selection and Functional Adaptation in a Cetacean Visual Pigment.

    Dungan, Sarah Z; Kosyakov, Alexander; Chang, Belinda S W

    2016-02-01

    Cetaceans have undergone a remarkable evolutionary transition that was accompanied by many sensory adaptations, including modification of the visual system for underwater environments. Recent sequencing of cetacean genomes has made it possible to begin exploring the molecular basis of these adaptations. In this study we use in vitro expression methods to experimentally characterize the first step of the visual transduction cascade, the light activation of rhodopsin, for the killer whale. To investigate the spectral effects of amino acid substitutions thought to correspond with absorbance shifts relative to terrestrial mammals, we used the orca gene as a background for the first site-directed mutagenesis experiments in a cetacean rhodopsin. The S292A mutation had the largest effect, and was responsible for the majority of the spectral difference between killer whale and bovine (terrestrial) rhodopsin. Using codon-based likelihood models, we also found significant evidence for positive selection in cetacean rhodopsin sequences, including on spectral tuning sites we experimentally mutated. We then investigated patterns of ecological divergence that may be correlated with rhodopsin functional variation by using a series of clade models that partitioned the data set according to phylogeny, habitat, and foraging depth zone. Only the model partitioning according to depth was significant. This suggests that foraging dives might be a selective regime influencing cetacean rhodopsin divergence, and our experimental results indicate that spectral tuning may be playing an adaptive role in this process. Our study demonstrates that combining computational and experimental methods is crucial for gaining insight into the selection pressures underlying molecular evolution. PMID:26486871

  2. Integration of spectral domain optical coherence tomography with microperimetry generates unique datasets for the simultaneous identification of visual function and retinal structure in ophthalmological applications

    Koulen, Peter; Gallimore, Gary; Vincent, Ryan D.; Sabates, Nelson R.; Sabates, Felix N.

    2011-06-01

    Conventional perimeters are used routinely in various eye disease states to evaluate the central visual field and to quantitatively map sensitivity. However, standard automated perimetry proves difficult for retina and specifically macular disease due to the need for central and steady fixation. Advances in instrumentation have led to microperimetry, which incorporates eye tracking for placement of macular sensitivity values onto an image of the macular fundus thus enabling a precise functional and anatomical mapping of the central visual field. Functional sensitivity of the retina can be compared with the observed structural parameters that are acquired with high-resolution spectral domain optical coherence tomography and by integration of scanning laser ophthalmoscope-driven imaging. Findings of the present study generate a basis for age-matched comparison of sensitivity values in patients with macular pathology. Microperimetry registered with detailed structural data performed before and after intervention treatments provides valuable information about macular function, disease progression and treatment success. This approach also allows for the detection of disease or treatment related changes in retinal sensitivity when visual acuity is not affected and can drive the decision making process in choosing different treatment regimens and guiding visual rehabilitation. This has immediate relevance for applications in central retinal vein occlusion, central serous choroidopathy, age-related macular degeneration, familial macular dystrophy and several other forms of retina related visual disability.

  3. Math majors' visual proofs in a dynamic environment: the case of limit of a function and the ɛ-δ approach

    Caglayan, Günhan

    2015-08-01

    Despite few limitations, GeoGebra as a dynamic geometry software stood as a powerful instrument in helping university math majors understand, explore, and gain experiences in visualizing the limits of functions and the ɛ - δ formalism. During the process of visualizing a theorem, the order mattered in the sequence of constituents. Students made use of such rich constituents as finger-hand gestures and cursor gestures in an attempt to keep a record of visual demonstration in progress, while being aware of the interrelationships among these constituents and the transformational aspect of the visually proving process. Covariational reasoning along with interval mapping structures proved to be the key constituents in the visualizing and sense-making of a limit theorem using the delta-epsilon formalism. Pedagogical approaches and teaching strategies based on experimental mathematics - mindtool - consituential visual proofs trio would permit students to study, construct, and meaningfully connect the new knowledge to the previously mastered concepts and skills in a manner that would make sense for them.

  4. Global Motion Perception in 2-Year-Old Children: A Method for Psychophysical Assessment and Relationships With Clinical Measures of Visual Function

    Yu, Tzu-Ying; Jacobs, Robert J; Anstice, Nicola S.; Paudel, Nabin; Harding, Jane E; Thompson, Benjamin

    2013-01-01

    Global motion perception is susceptible to abnormal development and may provide a sensitive measure of visual cortex function. We describe and validate a technique for measuring global motion perception in 2-year-old children, and relate global motion perception to acuity and stereopsis.

  5. Luminol functionalized gold nanoparticles as colorimetric and chemiluminescent probes for visual, label free, highly sensitive and selective detection of minocycline

    In this work, luminol functionalized gold nanoparticles (LuAuNPs) were used as colorimetric and chemiluminescent probes for visual, label free, sensitive and selective detection of minocycline (MC). The LuAuNPs were prepared by simple one-pot reduction of HAuCl4 with luminol, which exhibited a good chemiluminescence (CL) activity owing to the presence of luminol molecules on their surface and surface plasmon resonance absorption. In the absence of MC, the color of LuAuNPs was wine red and their size was relatively small (∼25 nm), which could react with silver nitrate, producing a strong CL emission. Upon the addition of MC at acidic buffer solutions, the electrostatic interaction between positively charged MC and negatively charged LuAuNPs caused the aggregation of LuAuNPs, generating a purple or blue color. Simultaneously, the aggregated LuAuNPs did not effectively react with silver nitrate, producing a weak CL emission. The signal change was linearly dependent on the logarithm of MC concentration in the range from 30 ng to 1.0 μg for colorimetric detection and from 10 ng to 1.0 μg for CL detection. With colorimetry, a detection limit of 22 ng was achieved, while the detection limit for CL detection modality was 9.7 ng. (paper)

  6. Visualization analysis and design

    Munzner, Tamara

    2015-01-01

    Visualization Analysis and Design provides a systematic, comprehensive framework for thinking about visualization in terms of principles and design choices. The book features a unified approach encompassing information visualization techniques for abstract data, scientific visualization techniques for spatial data, and visual analytics techniques for interweaving data transformation and analysis with interactive visual exploration. It emphasizes the careful validation of effectiveness and the consideration of function before form. The book breaks down visualization design according to three questions: what data users need to see, why users need to carry out their tasks, and how the visual representations proposed can be constructed and manipulated. It walks readers through the use of space and color to visually encode data in a view, the trade-offs between changing a single view and using multiple linked views, and the ways to reduce the amount of data shown in each view. The book concludes with six case stu...

  7. Development of an Arabic version of the National Eye Institute Visual Function Questionnaire as a tool to study eye diseases patients in Egypt

    Nizar; Saleh; Abdelfattah; Mohamed; Amgad; Ahmed; A; Salama; Marina; E; Israel; Ghada; A; Elhawary; Ahmed; E; Radwan; Mohamed; M; Elgayar; Tamer; M; EL; Nakhal; Islam; T; Elkhateb; Heba; A; Hashem; Doha; K; Embaby; Amira; A; Elabd; Reem; K; Elwy; Magdi; S; Yacoub; Hamdy; Salem; Mohamed; Abdel-Baqy; Ahmad; Kassem

    2014-01-01

    AIM:To develop and test an Arabic version of the National Eye Institute Visual Function Questionnaire-25(NEI-VFQ-25).METHODS:NEI-VFQ-25 was translated into Arabic according to WHO translation guidelines. We enrolled adult consenting patients with bilateral chronic eye diseases who presented to 14 hospitals across Egypt from October to December 2012, and documented their clinical findings. Psychometric properties were then tested using STATA.RESULTS:We recruited 379 patients, whose mean age was(54.5±15)y. Of 46.2% were males, 227 had cataract,31 had glaucoma, 23 had retinal detachment, 37 had diabetic retinopathy, and 61 had miscellaneous visual defects. Non-response rate and the floor and ceiling numbers of the Arabic version(ARB-VFQ-25) were calculated. Internal consistency was high in all subscales(except general health), with Cronbach-α ranging from0.702-0.911. Test-retest reliability was high(intraclass correlation coefficient 0.79).CONCLUSION:RB-VFQ-25 isareliableandvalidtool for assessing visual functions of Arabic speaking patients. However, some questions had high non-response rates and should be substituted by available alternatives. Our results support the importance of including self-reported visual functions as part of routine ophthalmologic examination.

  8. Prism therapy and visual rehabilitation in homonymous visual field loss.

    O'Neill, Evelyn C

    2011-02-01

    Homonymous visual field defects (HVFD) are common and frequently occur after cerebrovascular accidents. They significantly impair visual function and cause disability particularly with regard to visual exploration. The purpose of this study was to assess a novel interventional treatment of monocular prism therapy on visual functioning in patients with HVFD of varied etiology using vision targeted, health-related quality of life (QOL) questionnaires. Our secondary aim was to confirm monocular and binocular visual field expansion pre- and posttreatment.

  9. Schizophrenia spectrum participants have reduced visual contrast sensitivity to chromatic (red/green and luminance (light/dark stimuli: new insights into information processing, visual channel function and antipsychotic effects

    Kristin Suzanne Cadenhead

    2013-08-01

    Full Text Available Background: Individuals with schizophrenia spectrum diagnoses have deficient visual information processing as assessed by a variety of paradigms including visual backward masking, motion perception and visual contrast sensitivity (VCS. In the present study, the VCS paradigm was used to investigate potential differences in magnocellular (M versus parvocellular (P channel function that might account for the observed information processing deficits of schizophrenia spectrum patients. Specifically, VCS for near threshold luminance (black/white stimuli is known to be governed primarily by the M channel, while VCS for near threshold chromatic (red/green stimuli is governed by the P channel. Methods: VCS for luminance and chromatic stimuli (counterphase-reversing sinusoidal gratings, 1.22 c/deg, 8.3 Hz was assessed in 53 patients with schizophrenia (including 5 off antipsychotic medication, 22 individuals diagnosed with schizotypal personality disorder and 53 healthy comparison subjects. Results: Schizophrenia spectrum groups demonstrated reduced VCS in both conditions relative to normals, and there was no significant group by condition interaction effect. Post-hoc analyses suggest that it was the patients with schizophrenia on antipsychotic medication as well as SPD participants who accounted for the deficits in the luminance condition. Conclusions: These results demonstrate visual information processing deficits in schizophrenia spectrum populations but do not support the notion of selective abnormalities in the function of subcortical channels as suggested by previous studies. Further work is needed in a longitudinal design to further assess VCS as a vulnerability marker for psychosis as well as the effect of antipsychotic agents on performance in schizophrenia spectrum populations.

  10. Double function of noninvasive intracranial pressure monitoring based on flash visual evoked potentials in unconscious patients with traumatic brain injury.

    Wang, Tingzhong; Ma, Shuang; Guan, Yongchang; Du, Jinghua; Liu, Guojun; Zhao, Xianlin

    2016-05-01

    Intracranial pressure (ICP) monitoring based on flash visual evoked potentials (F-VEP) is a noninvasive method of monitoring ICP. The early diagnosis of traumatic optic neuropathy (TON) in unconscious patients with traumatic brain injury (TBI) is a challenge. The aim of this study was to evaluate the function of F-VEP ICP monitoring in predicting TON and detecting contusion enlargement (CE) in unconscious TBI patients using a modified approach. A series of F-VEP ICP-monitored unconscious TBI patients were included in the study. The interocular differences in N2 wave latency (DL) and amplitude (DA) were obtained through monocular flash stimulation. The increases in ICP (dxP) and interchannel difference (dxDC) across various time points were obtained through binocular flash stimulation. The predictive power of DL and DA on TON, as well as of dxP and dxDC on CE, was assessed by logistic regression and receiver operating characteristic (ROC) curve analysis. Patients with TON had a longer DL and a higher DA than those without TON. The dxP and dxDC of patients with CE were both higher than those of patients without CE. The differences were statistically significant. The logistic regression showed that both DL and DA were predictors of TON, whereas only dxDC was a predictor of CE. However, the ROC curve analysis showed that DL had greater predictive power for TON, and dxDC had greater predictive power for CE. An F-VEP ICP monitoring system with a modified approach is beneficial for early diagnosis of TON and prediction of CE in unconscious TBI patients. PMID:26922509

  11. Visual local and global processing in low-functioning deaf individuals with and without autism spectrum disorder

    Maljaars, Jarymke; Noens, Ilse; Scholte, Evert; Verpoorten, Roger; van Berckelaer-Onnes, Ina

    2011-01-01

    Background: The ComFor study has indicated that individuals with intellectual disability (ID) and autism spectrum disorder (ASD) show enhanced visual local processing compared with individuals with ID only. Items of the ComFor with meaningless materials provided the best discrimination between the two samples. These results can be explained by the weak central coherence account. The main focus of the present study is to examine whether enhanced visual perception is also present in low-functio...

  12. Pulmonary emphysema quantitation with Computed Tomography. Comparison between the visual score with high resolution CT, expiratory density mask with spiral CT and lung function studies

    CT is the most accurate method to detect pulmonary emphysema in vivo. They compared prospectively two different methods for emphysema quantitation in 5 normal volunteers and 20 consecutive patients with chronic obstructive pulmonary disease (COPD). All subjects were submitted to function tests and HRCT; three scans were acquired at preselected levels during inspiration. The type and extent of pulmonary emphysema were defined by two independent observers under blind conditions. Disagreements were subsequently settled by consent. All subjects were also examined with expiratory spiral CT using a density mask program, at two different cut-off levels (-850,-900 HU). Visual score and expiratory spiral density mask values (-850 HU) were significantly correlated (r = 0.86), but the visual extent of emphysema was always higher than shown by expiratory spiral CT. The emphysema extent assessed with both CT methods correlated with the function result of expiratory airflow obstruction and gas diffusion impairment (visual score versus forced expiratory volume in one second: r = -0.81, versus single breath carbon monoxide diffusion: r = -0.78. Spiral expiratory density mask -850 HU versus forced expiratory volume in one second: r = -0.85 versus single breath carbon monoxide diffusion: r = -0.77). When -900 HU was used as the cut-off value for the expiratory density mask, the correlation with single breath carbon monoxide diffusion worsened (r = -0.56). Visual score and expiratory density mask -850 HU gave similar results and permitted COPD patients to be clearly distinguished from normal controls (p < 0.01). They believe the true residual volume should lie somewhere in between the CT value and the function results with the helium dilution technique and conclude that the extent of pulmonary emphysema can be confidently assessed with CT methods. Finally, the simple visual score may be as reliable as such highly sophisticated new methods as the spiral expiratory density mask

  13. Neurophysiological assessment of auditory, peripheral nerve, somatosensory, and visual system function after developmental exposure to gasoline, E15, and E85 vapors.

    Herr, David W; Freeborn, Danielle L; Degn, Laura; Martin, Sheppard A; Ortenzio, Jayna; Pantlin, Lara; Hamm, Charles W; Boyes, William K

    2016-01-01

    The use of gasolines blended with a range of ethanol concentrations may result in inhalation of vapors containing a variable combination of ethanol with other volatile gasoline constituents. The possibility of exposure and potential interactions between vapor constituents suggests the need to evaluate the possible risks of this complex mixture. Previously we evaluated the effects of developmental exposure to ethanol vapors on neurophysiological measures of sensory function as a component of a larger project evaluating developmental ethanol toxicity. Here we report an evaluation using the same battery of sensory function testing in offspring of pregnant dams exposed during gestation to condensed vapors of gasoline (E0), gasoline blended with 15% ethanol (E15) or gasoline blended with 85% ethanol (E85). Pregnant Long-Evans rats were exposed to target concentrations 0, 3000, 6000, or 9000ppm total hydrocarbon vapors for 6.5h/day over GD9 - GD20. Sensory evaluations of male offspring began as adults. The electrophysiological testing battery included tests of: peripheral nerve (compound action potentials, nerve conduction velocity [NCV]), somatosensory (cortical and cerebellar evoked potentials), auditory (brainstem auditory evoked responses), and visual functions. Visual function assessment included pattern elicited visual evoked potentials (VEP), VEP contrast sensitivity, dark-adapted (scotopic) electroretinograms (ERGs), light-adapted (photopic) ERGs, and green flicker ERGs. The results included sporadic statistically significant effects, but the observations were not consistently concentration-related and appeared to be statistical Type 1 errors related to multiple dependent measures evaluated. The exposure concentrations were much higher than can be reasonably expected from typical exposures to the general population during refueling or other common exposure situations. Overall the results indicate that gestational exposure of male rats to ethanol/gasoline vapor

  14. Longitudial observation of dynamic changes in cortical function and white matter fibrous structure of patients with visual pathway lesions by blood oxygenation level dependent-functional magnetic resonance imaging combined with diffusion tensor imaging

    2007-01-01

    BACKGROUND: Functional magnetic resonance imaging (fMRI) is initially used for visual cortex location.However, the application of fMRI in investigating the development of visual pathway lesions needs to be further observed.OBJECTIVE: This study is to longitudially observe the dynamic changes in cortical function and white matter fibrous structure of patients with visual pathway lesions by blood oxygenation level dependent-functional magnetic resonance imaging (BOLD-fMRI) combined with diffusion tensor imaging (DTI), and to analyze the characteristics of brain function and structural recombination at convalescent period of lesions.DESIGN: Randomized controlled observation.SETTING: Department of Radiology, the General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS: Eight patients with unilateral or bilateral visual disorder caused by visual pathway lesions,who admitted to Department of Radiology, the General Hospital of Nanjing Military Area Command of Chinese PLA from January to September 2006 were involved, and served as experimental subjects. The patients, 6 males and 2 females, were aged 16 - 67 years. They had visual disorder confirmed by clinical examination, i.e. visual pathway lesion, which was further diagnosed by MR or CT. Another 12 subjects generally matching to those patients of experimental group in gender, age and sight, who received health examination in synchronization were involved and served as controls. The subjects had no history of eye diseases. Their binocular visual acuity (or corrected visual acuity) was over 1.0. Both routine examination of ophthalmology and examination of fundus were normal. Informed consents of detected items were obtained from all the subjects.METHODS: Signa Excite HD 1.5T magnetic resonance imaging system with 16 passages (GE Company,USA) and coil with 8 passages were used; brain functional stimulus apparatus (SAV-8800. Meide Company) was used for showing experimental mission. At the early stage

  15. Visual function and fine-motor control in small-for-gestational age infants Função visual e controle motor apendicular em lactentes pequenos para a idade gestacional

    Heloisa G.R.G. Gagliardo; VANDA M. G. GONÇALVES; Maria Cecilia M.P. Lima; Maria de Fatima de C. Francozo; Abimael Aranha Netto

    2004-01-01

    OBJECTIVE: To compare visual function and fine-motor control of full-term infants small-for-gestational age (SGA) and appropriate for gestational age (AGA), in the first three months. METHOD: We evaluated prospectively 31 infants in the 1st month; 33 in the 2nd and 34 infants in the 3rd month, categorized as full-term; birth weight less than 10th percentile for SGA and 25th to 90th percentile for the AGA group. Genetic syndromes, infections, multiple congenital malformations were excluded. Th...

  16. Prenatal music stimulation facilitates the postnatal functional development of the auditory as well as visual system in chicks (Gallus domesticus)

    Saborni Roy; Tapas C Nag; Ashish Datt Upadhyay; Rashmi Mathur; Suman Jain

    2014-03-01

    Rhythmic sound or music is known to improve cognition in animals and humans. We wanted to evaluate the effects of prenatal repetitive music stimulation on the remodelling of the auditory cortex and visual Wulst in chicks. Fertilized eggs (0 day) of white leghorn chicken (Gallus domesticus) during incubation were exposed either to music or no sound from embryonic day 10 until hatching. Auditory and visual perceptual learning and synaptic plasticity, as evident by synaptophysin and PSD-95 expression, were done at posthatch days (PH) 1, 2 and 3. The number of responders was significantly higher in the music stimulated group as compared to controls at PH1 in both auditory and visual preference tests. The stimulated chicks took significantly lesser time to enter and spent more time in the maternal area in both preference tests. A significantly higher expression of synaptophysin and PSD-95 was observed in the stimulated group in comparison to control at PH1-3 both in the auditory cortex and visual Wulst. A significant inter-hemispheric and gender-based difference in expression was also found in all groups. These results suggest facilitation of postnatal perceptual behaviour and synaptic plasticity in both auditory and visual systems following prenatal stimulation with complex rhythmic music.

  17. Visualization system on ITBL

    Visualization systems PATRAS/ITBL and AVS/ITBL, which are based on visualization software PATRAS and AVS/Express respectively, have been developed on a global, heterogeneous computing environment, Information Technology Based Laboratory (ITBL). PATRAS/ITBL allows for real-time visualization of the numerical results acquired from coupled multi-physics numerical simulations, executed on different hosts situated in remote locations. AVS/ITBL allow for post processing visualization. The scientific data located in remote sites may be selected and visualized on a web browser installed in a user terminal. The global structure and main functions of these systems are presented. (author)

  18. Roles of STAT3/SOCS3 Pathway in Regulating the Visual Function and Ubiquitin-Proteasome-dependent Degradation of Rhodopsin during Retinal Inflammation*

    Ozawa, Yoko; Nakao, Keiko; Kurihara, Toshihide; Shimazaki, Takuya; Shimmura, Shigeto; Ishida, Susumu; Yoshimura, Akihiko; Tsubota, Kazuo; Okano, Hideyuki

    2008-01-01

    Inflammatory cytokines cause tissue dysfunction. We previously reported that retinal inflammation down-regulates rhodopsin expression and impairs visual function by an unknown mechanism. Here, we demonstrate that rhodopsin levels were preserved by suppressor of cytokine signaling 3 (SOCS3), a negative feedback regulator of STAT3 activation. SOCS3 was expressed mainly in photoreceptor cells in the retina. In the SOCS3-deficient retinas, rhodopsin protein levels dropped sooner, and the reductio...

  19. Students’ Communicative Resources in Relation to Their Conceptual Understanding—The Role of Non-Conventionalized Expressions in Making Sense of Visualizations of Protein Function

    Rundgren, Carl-Johan; Hirsch, Richard; Chang Rundgren, Shu-Nu; Tibell, Lena

    2012-01-01

    This study examines how students explain their conceptual understanding of protein function using visualizations. Thirteen upper secondary students, four tertiary students (studying chemical biology), and two experts were interviewed in semi-structured interviews. The interviews were structured around 2D illustrations of proteins and an animated representation of water transport through a channel in the cell membrane. In the analysis of the transcripts, a score, based on the SOLO-taxonomy, wa...

  20. AN IMAGE ENHANCEMENT ENVIRONMENT DESIGNED AT 32-BIT VERSION OF VISUAL BASIC 4 PROGRAMMING LANGUAGE USING THE WIN32 API FUNCTIONS

    Aydın KIZILKAYA; Mustafa TEMİZ; TOKAT, Sezai

    2000-01-01

    In this paper, using the Win32 API (Application Programming Interface) functions and MDI (Multiple Document Interface) programming technique, which is main principle of Windows system, designed an image enhancement environment at 32-bit version of Visual Basic 4 programming language is investigated. Image enhancement algorithms could be easily applied in this environment and each of results obtained could be separately showed in frames on same environment. Image enhancement techniques used i...

  1. 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"

    Juliana Malta; Daniela Endriss; Sueli Rached; Terezinha Moura; Liana Ventura

    2006-01-01

    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 s...

  2. Substantial interobserver variation of thyroid volume and function by visual evaluation of thyroid (99m)Tc scintigraphy

    Soelberg, Kerstin K; Grupe, Peter; Boel-Jørgensen, Henrik; Jørgensen, Peter; Fast, Søren; Nielsen, Viveque E; Hegedüs, Laszlo; Bonnema, Steen J

    2014-01-01

    (99m)Tc-pertechnetate scintigraphy is much used in the evaluation of patients with nodular goitre. We investigated the ability of experienced observers to estimate the thyroid 24-h (131)I uptake (RAIU) and the thyroid volume by visual evaluation of the scintigram.......(99m)Tc-pertechnetate scintigraphy is much used in the evaluation of patients with nodular goitre. We investigated the ability of experienced observers to estimate the thyroid 24-h (131)I uptake (RAIU) and the thyroid volume by visual evaluation of the scintigram....

  3. Quantification of Emphysema with a Three-Dimensional Chest CT Scan: Correlation with the Visual Emphysema Scoring on Chest CT, Pulmonary Function Tests and Dyspnea Severity

    Park, Hyun Jeong; Hwang, Jung Hwa [Dept. of Radiology, Soonchunhyang University Seoul Hospital, Seoul (Korea, Republic of)

    2011-09-15

    We wanted to prospectively evaluate the correlation between the quantification of emphysema using 3D CT densitometry with the visual emphysema score, pulmonary function tests (PFT) and the dyspnea score in patients with chronic obstructive pulmonary disease (COPD). Non-enhanced chest CT with 3D reconstruction was performed in 28 men with COPD (age 54-88 years). With histogram analysis, the total lung volume, mean lung density and proportion of low attenuation lung volume below predetermined thresholds were measured. The CT parameters were compared with the visual emphysema score, the PFT and the dyspnea score. A low attenuation lung volume below -950 HU was well correlated with the DLco and FEV{sub 1}/FVC. A Low attenuation lung volume below -950 HU and -930 HU was correlated with visual the emphysema score. A low attenuation lung volume below -950 HU was correlated with the dyspnea score, although the correlations between the other CT parameters and the dyspnea score were not significant. Objective quantification of emphysema using 3D CT densitometry was correlated with the visual emphysema score. A low attenuation lung volume below -950 HU was correlated with the DLco, the FEV{sub 1}/FVC and the dyspnea score.

  4. Quantification of Emphysema with a Three-Dimensional Chest CT Scan: Correlation with the Visual Emphysema Scoring on Chest CT, Pulmonary Function Tests and Dyspnea Severity

    We wanted to prospectively evaluate the correlation between the quantification of emphysema using 3D CT densitometry with the visual emphysema score, pulmonary function tests (PFT) and the dyspnea score in patients with chronic obstructive pulmonary disease (COPD). Non-enhanced chest CT with 3D reconstruction was performed in 28 men with COPD (age 54-88 years). With histogram analysis, the total lung volume, mean lung density and proportion of low attenuation lung volume below predetermined thresholds were measured. The CT parameters were compared with the visual emphysema score, the PFT and the dyspnea score. A low attenuation lung volume below -950 HU was well correlated with the DLco and FEV1/FVC. A Low attenuation lung volume below -950 HU and -930 HU was correlated with visual the emphysema score. A low attenuation lung volume below -950 HU was correlated with the dyspnea score, although the correlations between the other CT parameters and the dyspnea score were not significant. Objective quantification of emphysema using 3D CT densitometry was correlated with the visual emphysema score. A low attenuation lung volume below -950 HU was correlated with the DLco, the FEV1/FVC and the dyspnea score.

  5. Visual Local and Global Processing in Low-Functioning Deaf Individuals with and without Autism Spectrum Disorder

    Maljaars, J. P. W.; Noens, I. L. J.; Scholte, E. M.; Verpoorten, R. A. W.; van Berckelaer-Onnes, I. A.

    2011-01-01

    Background: The ComFor study has indicated that individuals with intellectual disability (ID) and autism spectrum disorder (ASD) show enhanced visual local processing compared with individuals with ID only. Items of the ComFor with meaningless materials provided the best discrimination between the two samples. These results can be explained by the…

  6. Subcortical BOLD responses during visual sexual stimulation vary as a function of implicit porn associations in women

    Borg, Charmaine; de Jong, Peter J.; Georgiadis, Janniko R.

    2014-01-01

    Lifetime experiences shape people's attitudes toward sexual stimuli. Visual sexual stimulation (VSS), for instance, may be perceived as pleasurable by some, but as disgusting or ambiguous by others. VSS depicting explicit penile-vaginal penetration (PEN) is relevant in this respect, because the act

  7. Ontogenetic improvement of visual function in the medaka Oryzias latipes based on an optomotor testing system for larval and adult fish

    Carvalho, P.S.M.; Noltie, D.B.; Tillitt, D.E.

    2002-01-01

    We developed a system for evaluation of visual function in larval and adult fish. Both optomotor (swimming) and optokinetic (eye movement) responses were monitored and recorded using a system of rotating stripes. The system allowed manipulation of factors such as width of the stripes used, rotation speed of the striped drum, and light illuminance levels within both the scotopic and photopic ranges. Precise control of these factors allowed quantitative measurements of visual acuity and motion detection. Using this apparatus, we tested the hypothesis that significant posthatch ontogenetic improvements in visual function occur in the medaka Oryzias latipes, and also that this species shows significant in ovo neuronal development. Significant improvements in the acuity angle alpha (ability to discriminate detail) were observed from approximately 5 degrees at hatch to 1 degree in the oldest adult stages. In addition, we measured a significant improvement in flicker fusion thresholds (motion detection skills) between larval and adult life stages within both the scotopic and photopic ranges of light illuminance. Ranges of flicker fusion thresholds (X?? ?? SD) at log I=1.96 (photopic) varied from 37.2 ?? 1.6 cycles/s in young adults to 18.6 ?? 1.6 cycles/s in young larvae 10 days posthatch. At log I= - 2.54 (scotopic), flicker fusion thresholds varied from 5.8 ?? 0.7 cycles/s in young adults to 1.7 ?? 0.4 cycles/s in young larvae 10 days posthatch. Light sensitivity increased approximately 2.9 log units from early hatched larval stages to adults. The demonstrated ontogenetic improvements in visual function probably enable the fish to explore new resources, thereby enlarging their fundamental niche. ?? 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.

  8. Correlation between Retinal Changes and Visual Function in Late-Stage Vogt-Koyanagi-Harada Disease: An Optical Coherence Tomography Study

    Min Zhou

    2015-01-01

    Full Text Available Purpose. To characterize the optical coherence tomography (OCT findings in late-stage Vogt-Koyanagi-Harada (VKH disease and its correlation with visual function. Methods. The records of patients with late-stage VKH disease (defined as ≥12 months from disease onset were retrospectively reviewed. The analysis focused on the OCT findings and microperimetry, in addition to the possible correlation between morphology and functional findings. Results. Twenty-nine patients (58 eyes were included. Mean age at onset was 34.24 ± 10.67 years. The OCT revealed that the outer retina and retinal pigment epithelium (RPE were mainly affected. These effects included RPE thickening and breakage or disappearance of the cone outer segment tip (COST line and/or inner segment/outer segment (IS/OS junction. The COST line and IS/OS results were related to macular function and the interval between symptom onset and initiation of high-dose corticosteroid treatment (all P<0.01. Eyes with intact COST lines demonstrated intact IS/OS and normal RPE layers as well as better visual function and normal retinal sensitivity. Conclusions. The OCT findings are strongly correlated with macular function, as well as other clinical findings in late-stage VKH. With respect to the COST line and retinal sensitivity especially, the OCT and microperimetry findings may be useful for evaluating later-stage VKH.

  9. Characteristics of Left Ventricular Impaired Functional Indices in Patients with Coronary Heart Disease According to Visual Estimation and Velocity Vector Imaging

    Petrova Е.B.

    2014-09-01

    Full Text Available The aim of the investigation was to estimate the diagnostic capabilities of left ventricular (LV functional indices in patients with coronary heart disease (CHD using conventional imaging techniques (echoCG and VVI technology. Materials and Methods. 52 patients with CHD were examined. By visual estimation (echoCG of LV segmental contractility all patients were divided into two groups: without LV contractile dysfunction (n=26; with segmental contractile dysfunction (n=26. The investigation of LV function using VVI system included the study of longitudinal, radial and circular LV fibers, and the analysis of rotation indices. Results and Discussion. VVI system helped to reveal in all patients systolic dysfunction and abnormal strain rate of LV myocardium. Patients of both groups were found to have dysfunction of longitudinal and circular fibers of LV myocardium. Decreased indices of radial fiber function were recorded in a group of patients with segmental contractility dysfunction. Rotation function analysis was impossible in visual estimation. VVI application enabled to find disturbed rotation of basal and apical LV parts. So, the patients of both groups had decreased apical rotation indices, and 14 of them were recorded to have disturbed apical and basal rotational direction of LV. Conclusion. The use of VVI system enables to study in more detail the characteristics of LV function in CHD patients and reveal the alteration of those indices which are not found in visual control. The detection of disturbed strain and rotational properties of LV myocardium is the most urgent problem in patients with regular contractility that makes it possible to define well the management of such patients.

  10. A comparison of the sensitivity of EQ-5D, SF-6D and TTO utility values to changes in vision and perceived visual function in patients with primary open-angle glaucoma

    Bozzani Fiammetta Maria

    2012-08-01

    Full Text Available Abstract Background Economic viability of treatments for primary open-angle glaucoma (POAG should be assessed objectively to prioritise health care interventions. This study aims to identify the methods for eliciting utility values (UVs most sensitive to differences in visual field and visual functioning in patients with POAG. As a secondary objective, the dimensions of generic health-related and vision-related quality of life most affected by progressive vision loss will be identified. Methods A total of 132 POAG patients were recruited. Three sets of utility values (EuroQoL EQ-5D, Short Form SF-6D, Time Trade Off and a measure of perceived visual functioning from the National Eye Institute Visual Function Questionnaire (VFQ-25 were elicited during face-to-face interviews. The sensitivity of UVs to differences in the binocular visual field, visual acuity and visual functioning measures was analysed using non-parametric statistical methods. Results Median utilities were similar across Integrated Visual Field score quartiles for EQ-5D (P = 0.08 whereas SF-6D and Time-Trade-Off UVs significantly decreased (p = 0.01 and p = 0.001, respectively. The VFQ-25 score varied across Integrated Visual Field and binocular visual acuity groups and was associated with all three UVs (P ≤ 0.001; most of its vision-specific sub-scales were associated with the vision markers. The most affected dimension was driving. A relationship with vision markers was found for the physical component of SF-36 and not for any dimension of EQ-5D. Conclusions The Time-Trade-Off was more sensitive than EQ-5D and SF-6D to changes in vision and visual functioning associated with glaucoma progression but could not measure quality of life changes in the mildest disease stages.

  11. Multimodal Preception and Multicriterion Control of Nested Systems. 3; A Functional Visual Assessment Test for Human Health Maintenance and Countermeasure Evaluation

    Riccio, Gary E.; McDonald, P. Vernon; Bloomberg, Jacob

    1999-01-01

    Our theoretical and empirical research on the whole-body coordination during locomotion led to a Phase 1 SBIR grant from NASA JSC. The purpose of the SBIR grant was to design an innovative system for evaluating eye-head-trunk coordination during whole-body perturbations that are characteristic of locomotion. The approach we used to satisfy the Phase 1 objectives was based on a structured methodology for the development of human-systems technology. Accordingly the project was broken down into a number of tasks and subtasks. In sequence, the major tasks were: (1) identify needs for functional assessment of visual acuity under conditions involving whole-body perturbation within the NASA Space Medical Monitoring and Countermeasures (SMMaC) program and in other related markets; (2) analyze the needs into the causes and symptoms of impaired visual acuity under conditions involving whole-body perturbation; (3) translate the analyzed needs into technology requirements for the Functional Visual Assessment Test (FVAT); (4) identify candidate technology solutions and implementations of FVAT; and (5) prioritize and select technology solutions. The work conducted in these tasks is described in this final volume of the series on Multimodal Perception and Multicriterion Control of Nested Systems. While prior volumes (1 and 2) in the series focus on theoretical foundations and novel data-analytic techniques, this volume addresses technology that is necessary for minimally intrusive data collection and near-real-time data analysis and display.

  12. The nucleus of the optic tract. Its function in gaze stabilization and control of visual-vestibular interaction

    Cohen, B.; Reisine, H.; Yokota, J. I.; Raphan, T.

    1992-01-01

    1. Electrical stimulation of the nucleus of the optic tract (NOT) induced nystagmus and after-nystagmus with ipsilateral slow phases. The velocity characteristics of the nystagmus were similar to those of the slow component of optokinetic nystagmus (OKN) and to optokinetic after-nystagmus (OKAN), both of which are produced by velocity storage in the vestibular system. When NOT was destroyed, these components disappeared. This indicates that velocity storage is activated from the visual system through NOT. 2. Velocity storage produces compensatory eye-in-head and head-on-body movements through the vestibular system. The association of NOT with velocity storage implies that NOT helps stabilize gaze in space during both passive motion and active locomotion in light with an angular component. It has been suggested that "vestibular-only" neurons in the vestibular nuclei play an important role in generation of velocity storage. Similarities between the rise and fall times of eye velocity during OKN and OKAN to firing rates of vestibular-only neurons suggest that these cells may receive their visual input through NOT. 3. One NOT was injected with muscimol, a GABAA agonist. Ipsilateral OKN and OKAN were lost, suggesting that GABA, which is an inhibitory transmitter in NOT, acts on projection pathways to the brain stem. A striking finding was that visual suppression and habituation of contralateral slow phases of vestibular nystagmus were also abolished after muscimol injection. The latter implies that NOT plays an important role in producing visual suppression of the VOR and habituating its time constant. 4. Habituation is lost after nodulus and uvula lesions and visual suppression after lesions of the flocculus and paraflocculus. We postulate that the disappearance of vestibular habituation and of visual suppression of vestibular responses after muscimol injections was due to dysfacilitation of the prominent NOT-inferior olive pathway, inactivating climbing fibers from

  13. Dysfunctions of visual and auditory Gestalt perception (amusia) after stroke : Behavioral correlates and functional magnetic resonance imaging

    Rosemann, Stephanie Heike

    2016-01-01

    Music is a special and unique part of human nature. Not only actively playing (making music in a group or alone) but also passive listening to music involves a richness of processes to make music the ideal tool to investigate how the human brain works. Acquired amusia denotes the impaired perception of melodies, rhythms, and the associated disability to enjoy music which can occur after a stroke. Many amusia patients also show deficits in visual perception, language, memory, and attention. He...

  14. Temporal Changes in Functional Magnetic Resonance Imaging Activation of Heterosexual Couples for Visual Stimuli of Loved Partners

    Kim, Won; Kim, Seungyeon; Jeong, Jaeseung; Lee, Kyung-Uk; Ahn, Kook-Jin; Chung, Yong-An; Hong, Keun-Young; Chae, Jeong-Ho

    2009-01-01

    Objective Previous neuroimaging studies on romantic love have focused on determining how the visual stimuli that serve as a representation of loved ones induce the neural activation patterns of romantic love. The purpose of this study was to investigate the temporal changes in romantic love over a period of 6 months and their correlated neurophysiological changes. Methods Five heterosexual couples (n=10, mean age 21.1±1.97) who started dating not less than 100 days previously were recruited t...

  15. Requirement of the nicotinic acetylcholine receptor β2 subunit for the anatomical and functional development of the visual system

    Rossi, Francesco Mattia; Pizzorusso, Tommaso; Porciatti, Vittorio; Marubio, Lisa M.; Maffei, Lamberto; Changeux, Jean-Pierre

    2001-01-01

    In the mammalian visual system the formation of eye-specific layers at the thalamic level depends on retinal waves of spontaneous activity, which rely on nicotinic acetylcholine receptor activation. We found that in mutant mice lacking the β2 subunit of the neuronal nicotinic receptor, but not in mice lacking the α4 subunit, retinofugal projections do not segregate into eye-specific areas, both in the dorso-lateral geniculate nucleus and in the superior colliculus. ...

  16. A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function

    Hatch, Bryndon B; Moshirfar, Majid; Ollerton, Andrew J; Sikder, Shameema; Mifflin, Mark D.

    2011-01-01

    Purpose: To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs) in eyes with stable myopia undergoing either photo-refractive keratectomy (PRK) or thin-flap laser in situ keratomileusis (LASIK) (intended flap thickness of 90 μm) using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively. Methods: In this prospective, masked, and randomized pilot study, refractiv...

  17. A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function

    Moshirfar, Majid

    2011-01-01

    Bryndon B Hatch1, Majid Moshirfar1, Andrew J Ollerton1, Shameema Sikder2, Mark D Mifflin11John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USAPurpose: To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs) in eyes with stable myopia undergoing either photorefractive keratectomy (PRK) or thin-flap laser in situ keratomileusis (LASIK) (intended ...

  18. Increased Amygdala and Visual Cortex Activity and Functional Connectivity towards Stimulus Novelty Is Associated with State Anxiety

    Ousdal, Olga T; Andreassen, Ole A; Server, Andres; Jensen, Jimmy

    2014-01-01

    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 t...

  19. Increased amygdala and visual cortex activity and functional connectivity towards stimulus novelty is associated with state anxiety

    2014-01-01

    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 t...

  20. Visual agnosia.

    Álvarez, R; Masjuan, J

    2016-03-01

    Visual agnosia is defined as an impairment of object recognition, in the absence of visual acuity or cognitive dysfunction that would explain this impairment. This condition is caused by lesions in the visual association cortex, sparing primary visual cortex. There are 2 main pathways that process visual information: the ventral stream, tasked with object recognition, and the dorsal stream, in charge of locating objects in space. Visual agnosia can therefore be divided into 2 major groups depending on which of the two streams is damaged. The aim of this article is to conduct a narrative review of the various visual agnosia syndromes, including recent developments in a number of these syndromes. PMID:26358494

  1. The effectiveness of racket-sport intervention on visual perception and executive functions in children with mild intellectual disabilities and borderline intellectual functioning

    Chen MD; Tsai HY; Wang CC; Wuang YP

    2015-01-01

    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 fu...

  2. Post re-anastomosis demonstration of regain in function in non-visualized upper half of kidney in a dual arterial allogenic renal graft on renal scintigraphy

    A young male patient with end stage renal disease underwent renal allograft having dual arterial supply. Immediate post-operative urine output dropped, an urgent Technetium-99m-mercaptoacetyltriglycine (99mTc-MAG3) renogram revealed non-visualized upper-half and the preserved perfusion and parenchymal function of the small transplant kidney. Patient was re-explored and re-anastomosis was performed. A renogram at 24h post re-anastomosis revealed increase in the size of renal allograft, with preserved perfusion to the upper-half of transplant. Transplant kidney biopsy of the Upper-half showed acute tubular necrosis. 99mTc-MAG3renogram at 10 days post re-vascularization remains unchanged with persistent improvement at 2 months follow-up. We conclude that early recognition of renal functional loss allows early management and the high probability of salvaging the renal function

  3. Brain Activation in Response to Visually Evoked Sexual Arousal in Male-to-Female Transsexuals: 3.0 Tesla Functional Magnetic Resonance Imaging

    Oh, Seok Kyun; Kim, Gwang Won; Kang, Heoung Keun; Jeong, Gwang Woo [Chonnam National University, Gwangju (Korea, Republic of); Yang, Jong Chul [Chonbuk National University Medical School, Jeonju (Korea, Republic of); Kim, Seok Kwun [Dong-A University College of Medicine, Busan (Korea, Republic of)

    2012-06-15

    This study used functional magnetic resonance imaging (fMRI) to contrast the differential brain activation patterns in response to visual stimulation with both male and female erotic nude pictures in male-to-female (MTF) transsexuals who underwent a sex reassignment surgery. A total of nine healthy MTF transsexuals after a sex reassignment surgery underwent fMRI on a 3.0 Tesla MR Scanner. The brain activation patterns were induced by visual stimulation with both male and female erotic nude pictures. The sex hormone levels of the postoperative MTF transsexuals were in the normal range of healthy heterosexual females. The brain areas, which were activated by viewing male nude pictures when compared with viewing female nude pictures, included predominantly the cerebellum, hippocampus, putamen, anterior cingulate gyrus, head of caudate nucleus, amygdala, midbrain, thalamus, insula, and body of caudate nucleus. On the other hand, brain activation induced by viewing female nude pictures was predominantly observed in the hypothalamus and the septal area. Our findings suggest that distinct brain activation patterns associated with visual sexual arousal in postoperative MTF transsexuals reflect their sexual orientation to males.

  4. The capabilities and functions of Ta’ziye in modern visualization:The study of two versions of Ta’ziye “Moses and the poor Pilgrim”

    لزگی ،ندایی لزگی ،ندایی

    2009-01-01

    Full Text Available As the most important method of religious and ritual theater, Ta’ziye has many capabilities in Iran which can be used in different forms of modern visualization. The only element which has been studied in this kind of theater has been distancing in performance. Through studying the existent versions of Ta’ziye, one can find that there are other elements that have not been studied yet. The relationship between Ta’ziye and religious theater in their general form, and also the major themes of Ta’ziye, helps us to identify these capabilities better and better. Meanwhile, music as an expressive and performing element provides a basis that can be used in finding a new manner of expression in visual/dramatic works (music videos for example. Studying elements such as character replacement, transformation of time and place, function of music and the ways of affecting on audience, shows that Ta’ziye has special capabilities in visualization. The writers of this article have introduced a sample of Ta’ziye and studied two versions of it to present these capabilities

  5. Brain Activation in Response to Visually Evoked Sexual Arousal in Male-to-Female Transsexuals: 3.0 Tesla Functional Magnetic Resonance Imaging

    This study used functional magnetic resonance imaging (fMRI) to contrast the differential brain activation patterns in response to visual stimulation with both male and female erotic nude pictures in male-to-female (MTF) transsexuals who underwent a sex reassignment surgery. A total of nine healthy MTF transsexuals after a sex reassignment surgery underwent fMRI on a 3.0 Tesla MR Scanner. The brain activation patterns were induced by visual stimulation with both male and female erotic nude pictures. The sex hormone levels of the postoperative MTF transsexuals were in the normal range of healthy heterosexual females. The brain areas, which were activated by viewing male nude pictures when compared with viewing female nude pictures, included predominantly the cerebellum, hippocampus, putamen, anterior cingulate gyrus, head of caudate nucleus, amygdala, midbrain, thalamus, insula, and body of caudate nucleus. On the other hand, brain activation induced by viewing female nude pictures was predominantly observed in the hypothalamus and the septal area. Our findings suggest that distinct brain activation patterns associated with visual sexual arousal in postoperative MTF transsexuals reflect their sexual orientation to males.

  6. Visual Impairment, Hearing Loss and Cognitive Function in an Older Population: Longitudinal Findings from the Blue Mountains Eye Study

    Hong, Thomas; Mitchell, Paul; Burlutsky, George; Liew, Gerald; Wang, Jie Jin

    2016-01-01

    The presence of visual impairment (VI) and hearing loss (HL) with may be a marker for subsequent cognitive decline over time in older people. A prospective, longitudinal population-based study of the 3654 participants of the Blue Mountains Eye Study were assessed for the associations between VI and HL and a decline in mini-mental state examination (MMSE) scores over a duration of 10 years from the 5-year (baseline of this report) to the 15-year follow-up visits. MMSE was assessed at the 5-, 1...

  7. Functional architecture for disparity in macaque inferior temporal cortex and its relationship to the architecture for faces, color, scenes, and visual field.

    Verhoef, Bram-Ernst; Bohon, Kaitlin S; Conway, Bevil R

    2015-04-29

    Binocular disparity is a powerful depth cue for object perception. The computations for object vision culminate in inferior temporal cortex (IT), but the functional organization for disparity in IT is unknown. Here we addressed this question by measuring fMRI responses in alert monkeys to stimuli that appeared in front of (near), behind (far), or at the fixation plane. We discovered three regions that showed preferential responses for near and far stimuli, relative to zero-disparity stimuli at the fixation plane. These "near/far" disparity-biased regions were located within dorsal IT, as predicted by microelectrode studies, and on the posterior inferotemporal gyrus. In a second analysis, we instead compared responses to near stimuli with responses to far stimuli and discovered a separate network of "near" disparity-biased regions that extended along the crest of the superior temporal sulcus. We also measured in the same animals fMRI responses to faces, scenes, color, and checkerboard annuli at different visual field eccentricities. Disparity-biased regions defined in either analysis did not show a color bias, suggesting that disparity and color contribute to different computations within IT. Scene-biased regions responded preferentially to near and far stimuli (compared with stimuli without disparity) and had a peripheral visual field bias, whereas face patches had a marked near bias and a central visual field bias. These results support the idea that IT is organized by a coarse eccentricity map, and show that disparity likely contributes to computations associated with both central (face processing) and peripheral (scene processing) visual field biases, but likely does not contribute much to computations within IT that are implicated in processing color. PMID:25926470

  8. Flow visualization

    Merzkirch, Wolfgang

    1974-01-01

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

  9. Visual Impairment, Hearing Loss and Cognitive Function in an Older Population: Longitudinal Findings from the Blue Mountains Eye Study.

    Hong, Thomas; Mitchell, Paul; Burlutsky, George; Liew, Gerald; Wang, Jie Jin

    2016-01-01

    The presence of visual impairment (VI) and hearing loss (HL) with may be a marker for subsequent cognitive decline over time in older people. A prospective, longitudinal population-based study of the 3654 participants of the Blue Mountains Eye Study were assessed for the associations between VI and HL and a decline in mini-mental state examination (MMSE) scores over a duration of 10 years from the 5-year (baseline of this report) to the 15-year follow-up visits. MMSE was assessed at the 5-, 10- and 15-year follow-up visits. A decline ≥3 scores from 5-year to 10- or 15-year visits indicated possible cognitive decline. VI was defined as best-corrected visual acuity 40 decibels in the worse-ear and dual sensory impairment (DSI) was defined by the co-presence of VI and HL, detected at 5-year follow-up (baseline of this report). Participants with no VI and HL over the same 5- or 10-year corresponding period were controls. Associations of VI, HL and DSI with possible cognitive decline were assessed using logistic regression models adjusting for age and sex after excluding subjects with a stroke history. The presence of VI, HL or DSI was not associated with possible cognitive decline over 5 years (odds ratio (OR) 0.84, 95% confidence-intervals (CI) 0.40-1.79, OR 1.02, 95% CI 0.61-1.70 and 1.41, 95% CI 0.54-3.72, respectively) or 10 years (OR 1.09, 95% CI 0.52-2.30, OR 1.09, 95% CI 0.65-1.82 and 1.15, 95% CI 0.28-4.73, respectively). There were no changes to these findings after adjustment for other potential confounders. Age was significantly associated with possible cognitive decline (OR 1.07, 95% CI 1.04-1.10 for both periods). Neither visual impairment, hearing loss nor dual sensory impairment was independently associated with subsequent decline in cognition. PMID:26808979

  10. Visual Impairment, Hearing Loss and Cognitive Function in an Older Population: Longitudinal Findings from the Blue Mountains Eye Study.

    Thomas Hong

    Full Text Available The presence of visual impairment (VI and hearing loss (HL with may be a marker for subsequent cognitive decline over time in older people. A prospective, longitudinal population-based study of the 3654 participants of the Blue Mountains Eye Study were assessed for the associations between VI and HL and a decline in mini-mental state examination (MMSE scores over a duration of 10 years from the 5-year (baseline of this report to the 15-year follow-up visits. MMSE was assessed at the 5-, 10- and 15-year follow-up visits. A decline ≥3 scores from 5-year to 10- or 15-year visits indicated possible cognitive decline. VI was defined as best-corrected visual acuity 40 decibels in the worse-ear and dual sensory impairment (DSI was defined by the co-presence of VI and HL, detected at 5-year follow-up (baseline of this report. Participants with no VI and HL over the same 5- or 10-year corresponding period were controls. Associations of VI, HL and DSI with possible cognitive decline were assessed using logistic regression models adjusting for age and sex after excluding subjects with a stroke history. The presence of VI, HL or DSI was not associated with possible cognitive decline over 5 years (odds ratio (OR 0.84, 95% confidence-intervals (CI 0.40-1.79, OR 1.02, 95% CI 0.61-1.70 and 1.41, 95% CI 0.54-3.72, respectively or 10 years (OR 1.09, 95% CI 0.52-2.30, OR 1.09, 95% CI 0.65-1.82 and 1.15, 95% CI 0.28-4.73, respectively. There were no changes to these findings after adjustment for other potential confounders. Age was significantly associated with possible cognitive decline (OR 1.07, 95% CI 1.04-1.10 for both periods. Neither visual impairment, hearing loss nor dual sensory impairment was independently associated with subsequent decline in cognition.

  11. Coordinates transformation and learning control for visually-guided voluntary movement with iteration: a Newton-like method in a function space.

    Kawato, M; Isobe, M; Maeda, Y; Suzuki, R

    1988-01-01

    In order to control visually-guided voluntary movements, the central nervous system (CNS) must solve the following three computational problems at different levels: (1) determination of a desired trajectory in the visual coordinates, (2) transformation of the coordinates of the desired trajectory to the body coordinates and (3) generation of motor command. In this paper, the second and the third problems are treated at computational, representational and hardware levels of Marr. We first study the problems at the computational level, and then propose an iterative learning scheme as a possible algorithm. This is a trial and error type learning such as repetitive training of golf swing. The amount of motor command needed to coordinate activities of many muscles is not determined at once, but in a step-wise, trial and error fashion in the course of a set of repetitions. Actually, the motor command in the (n + 1)-th iteration is a sum of the motor command in the n-th iteration plus two modification terms which are, respectively, proportional to acceleration and speed errors between the desired trajectory and the realized trajectory in the n-th iteration. We mathematically formulate this iterative learning control as a Newton-like method in functional spaces and prove its convergence under appropriate mathematical conditions with use of dynamical system theory and functional analysis. Computer simulations of this iterative learning control of a robotic manipulator in the body or visual coordinates are shown. Finally, we propose that areas 2, 5, and 7 of the sensory association cortex are possible sites of this learning control. Further we propose neural network model which acquires transformation matrices from acceleration or velocity to motor command, which are used in these schemes. PMID:3179342

  12. [Multiscale functional imaging: reconstructing network dynamics from the synaptic echoes recorded in a single visual cortex neuron].

    Fregnac, Yves; Baudot, Pierre; Chavane, Frédéric; Marre, Olivier; Monier, Cyril; Pananceau, Marc; Sadoc, Gérard

    2009-04-01

    In vivo intracellular electrophysiology offers the unique possibility of listening to the "synaptic rumor " of the cortical network, captured by a recording electrode in a single V1 cell. It allows one to reconstruct the distribution of input sources in space and time, i.e. the effective network dynamics. We have used a reverse engineering method to demonstrate the propagation of visually evoked activity through lateral (and feedback) connectivity in the primary cortex of higher mammals. This approach, based on synaptic echography, is compared here with a real-time brain imaging technique based on voltage-sensitive dye imaging. The former method gives access to the microscopic convergence processes of single neurons, whereas the latter describes the macroscopic divergence process on the neuronal map. A combination of the two techniques can be used to elucidate the cortical origin of low-level (non attentive) binding processes participating in the emergence of Gestalt percepts. PMID:20120274

  13. Students' Communicative Resources in Relation to Their Conceptual Understanding—The Role of Non-Conventionalized Expressions in Making Sense of Visualizations of Protein Function

    Rundgren, Carl-Johan; Hirsch, Richard; Chang Rundgren, Shu-Nu; Tibell, Lena A. E.

    2012-10-01

    This study examines how students explain their conceptual understanding of protein function using visualizations. Thirteen upper secondary students, four tertiary students (studying chemical biology), and two experts were interviewed in semi-structured interviews. The interviews were structured around 2D illustrations of proteins and an animated representation of water transport through a channel in the cell membrane. In the analysis of the transcripts, a score, based on the SOLO-taxonomy, was given to each student to indicate the conceptual depth achieved in their explanations. The use of scientific terms and non-conventionalized expressions in the students' explanations were investigated based upon a semiotic approach. The results indicated that there was a positive relationship between use of scientific terms and level of education. However, there was no correlation between students' use of scientific terms and conceptual depth. In the interviews, we found that non-conventionalized expressions were used by several participants to express conceptual understanding and played a role in making sense of the visualizations of protein function. Interestingly, also the experts made use of non-conventionalized expressions. The results of our study imply that more attention should be drawn to students' use of scientific and non-conventionalized terms in relation to their conceptual understanding.

  14. Exploration of High-dimensional Scalar Function for Nuclear Reactor Safety Analysis and Visualization: A User's Guide to TopoXG*

    Dan Maljovec; Bei Wang; Valerio Pascucci; Peer-Timo Bremer; Michael Pernice; Diego Mandelli

    2012-10-01

    Large-scale simulation datasets can be modeled as high-dimensional scalar functions defined over a discrete sample of the domain. The goals of our proposed research are two-fold. First, we would like to provide structural analysis of 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. TopoXG is a software package that is designed to address these goals. The unique contribution of TopoXG lies in 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 TopoXG, by highlighting its analysis and visualization capabilities, and giving several use cases involving datasets from nuclear reactor safety simulations.

  15. Gene therapy provides long-term visual function in a pre-clinical model of retinitis pigmentosa

    Wert, Katherine J.; Davis, Richard J.; Sancho-Pelluz, Javier; Nishina, Patsy M.; Stephen H Tsang

    2012-01-01

    Approximately 36 000 cases of simplex and familial retinitis pigmentosa (RP) worldwide are caused by a loss in phosphodiesterase (PDE6) function. In the preclinical Pde6αnmf363 mouse model of this disease, defects in the α-subunit of PDE6 result in a progressive loss of photoreceptors and neuronal function. We hypothesized that increasing PDE6α levels using an AAV2/8 gene therapy vector could improve photoreceptor survival and retinal function. We utilized a vector with the cell-type-specific...

  16. Data visualization

    Azzam, Tarek

    2013-01-01

    Do you communicate data and information to stakeholders? In Part 1, we introduce recent developments in the quantitative and qualitative data visualization field and provide a historical perspective on data visualization, its potential role in evaluation practice, and future directions. Part 2 delivers concrete suggestions for optimally using data visualization in evaluation, as well as suggestions for best practices in data visualization design. It focuses on specific quantitative and qualitative data visualization approaches that include data dashboards, graphic recording, and geographic information systems (GIS). Readers will get a step-by-step process for designing an effective data dashboard system for programs and organizations, and various suggestions to improve their utility.

  17. Functional localization and visualization of the subthalamic nucleus from microelectrode recordings acquired during DBS surgery with unsupervised machine learning

    Wong, S.; Baltuch, G. H.; Jaggi, J. L.; Danish, S. F.

    2009-04-01

    Microelectrode recordings are a useful adjunctive method for subthalamic nucleus localization during deep brain stimulation surgery for Parkinson's disease. Attempts to quantitate and standardize this process, using single computational measures of neural activity, have been limited by variability in patient neurophysiology and recording conditions. Investigators have suggested that a multi-feature approach may be necessary for automated approaches to perform within acceptable clinical standards. We present a novel data visualization algorithm and several unique features that address these shortcomings. The algorithm extracts multiple computational features from the microelectrode neurophysiology and integrates them with tools from unsupervised machine learning. The resulting colour-coded map of neural activity reveals activity transitions that correspond to the anatomic boundaries of subcortical structures. Using these maps, a non-neurophysiologist is able to achieve sensitivities of 90% and 95% for STN entry and exit, respectively, to within 0.5 mm accuracy of the current gold standard. The accuracy of this technique is attributed to the multi-feature approach. This activity map can simplify and standardize the process of localizing the subthalamic nucleus (STN) for neurostimulation. Because this method does not require a stationary electrode for careful recording of unit activity for spike sorting, the length of the operation may be shortened.

  18. Visual imagery without visual perception?

    Helder Bértolo

    2005-01-01

    The question regarding visual imagery and visual perception remain an open issue. Many studies have tried to understand if the two processes share the same mechanisms or if they are independent, using different neural substrates. Most research has been directed towards the need of activation of primary visual areas during imagery. Here we review some of the works providing evidence for both claims. It seems that studying visual imagery in blind subjects can be us...

  19. Visual Language in Visual Communication

    Jia Wang

    2009-01-01

    In visual communication the design information is mainly communicated by visual language, the correct use of which is the standard of evaluation of a graphic design composition. Therefore it is necessary to understand and percept visual language properly. It will be helpful for viewers to percept the desired information from the designer as well as the significance within the work.

  20. Vision-related quality of life assessment using the NEI-VFQ-25 in adolescents and young adults with a history of congenital cataract.

    Kirwan, Caitriona

    2013-07-22

    To assess vision-specific health-related quality of life in adolescents and young adults with a history of congenital cataract using the National Eye Institute 25-item Visual Function Questionnaire (NEI-VFQ-25).

  1. Investigation of verbal and visual working memory by multi-channel time-resolved functional near-infrared spectroscopy

    Contini, D.; Caffini, M.; Re, R.; Zucchelli, L.; Spinelli, L.; Basso Moro, S.; Bisconti, S.; Ferrari, M.; Quaresima, V.; Cutini, S.; Torricelli, A.

    2013-03-01

    Working memory (WM) is fundamental for a number of cognitive processes, such as comprehension, reasoning and learning. WM allows the short-term maintenance and manipulation of the information selected by attentional processes. The goal of this study was to examine by time-resolved fNIRS neural correlates of the verbal and visual WM during forward and backward digit span (DF and DB, respectively) tasks, and symbol span (SS) task. A neural dissociation was hypothesised between the maintenance and manipulation processes. In particular, a dorsolateral/ventrolateral prefrontal cortex (DLPFC/VLPFC) recruitment was expected during the DB task, whilst a lateralised involvement of Brodmann Area (BA) 10 was expected during the execution of the DF task. Thirteen subjects were monitored by a multi-channel, dual-wavelength (690 and 829 nm) time-resolved fNIRS system during 3 minutes long DF and DB tasks and 4 minutes long SS task. The participants' mean memory span was calculated for each task: DF: 6.46+/-1.05 digits; DB: 5.62+/-1.26 digits; SS: 4.69+/-1.32 symbols. No correlation was found between the span level and the heart rate data (measured by pulse oximeter). As expected, DB elicited a broad activated area, in the bilateral VLPFC and the right DLPFC, whereas a more localised activation was observed over the right hemisphere during either DF (BA 10) or SS (BA 10 and 44). The robust involvement of the DLPFC during DB, compared to DF, is compatible with previous findings and with the key role of the central executive subserving in manipulating processes.

  2. Utilization of high resolution computed tomography to visualize the three dimensional structure and function of plant vasculature

    High resolution x-ray computed tomography (HRCT) is a non-destructive diagnostic imaging technique with sub-micron resolution capability that is now being used to evaluate the structure and function of plant xylem network in three dimensions (3D). HRCT imaging is based on the same principles as medi...

  3. Visual imagery without visual perception?

    Helder Bértolo

    2005-01-01

    Full Text Available The question regarding visual imagery and visual perception remain an open issue. Many studies have tried to understand if the two processes share the same mechanisms or if they are independent, using different neural substrates. Most research has been directed towards the need of activation of primary visual areas during imagery. Here we review some of the works providing evidence for both claims. It seems that studying visual imagery in blind subjects can be used as a way of answering some of those questions, namely if it is possible to have visual imagery without visual perception. We present results from the work of our group using visual activation in dreams and its relation with EEG’s spectral components, showing that congenitally blind have visual contents in their dreams and are able to draw them; furthermore their Visual Activation Index is negatively correlated with EEG alpha power. This study supports the hypothesis that it is possible to have visual imagery without visual experience.

  4. AN IMAGE ENHANCEMENT ENVIRONMENT DESIGNED AT 32-BIT VERSION OF VISUAL BASIC 4 PROGRAMMING LANGUAGE USING THE WIN32 API FUNCTIONS

    Aydın KIZILKAYA

    2000-01-01

    Full Text Available In this paper, using the Win32 API (Application Programming Interface functions and MDI (Multiple Document Interface programming technique, which is main principle of Windows system, designed an image enhancement environment at 32-bit version of Visual Basic 4 programming language is investigated. Image enhancement algorithms could be easily applied in this environment and each of results obtained could be separately showed in frames on same environment. Image enhancement techniques used in this environment are observed in spatial domain. With this program observing image enhancement techniques are contrast stretching, histogram equalization, thresholding, negative imaging, low-pass filtering, high-pass filtering and median filtering. In the filtering process of the images are utilized of the convolution techniques at this environment.

  5. Limbic areas are functionally decoupled and visual cortex takes a more central role during fear conditioning in humans

    Chrysa Lithari; Stephan Moratti; Nathan Weisz

    2016-01-01

    Going beyond the focus on isolated brain regions (e.g. amygdala), recent neuroimaging studies on fear conditioning point to the relevance of a network of mutually interacting brain regions. In the present MEG study we used Graph Theory to uncover changes in the architecture of the brain functional network shaped by fear conditioning. Firstly, induced power analysis revealed differences in local cortical excitability (lower alpha and beta power) between CS+ and CS− localized to somatosensory c...

  6. Traffic Visualization

    Picozzi, Matteo; Verdezoto, Nervo; Pouke, Matti;

    2013-01-01

    In this paper, we present a space-time visualization to provide city's decision-makers the ability to analyse and uncover important "city events" in an understandable manner for city planning activities. An interactive Web mashup visualization is presented that integrates several visualization...... techniques to give a rapid overview of traffic data. We illustrate our approach as a case study for traffic visualization systems, using datasets from the city of Oulu that can be extended to other city planning activities. We also report the feedback of real users (traffic management employees, traffic police...

  7. Visualizing the human connectome

    Margulies, D.; Böttger, J; Watanabe, A; Gorgolewski, K.

    2013-01-01

    Innovations in data visualization punctuate the landmark advances in human connectome research since its beginnings. From tensor glyphs for diffusion-weighted imaging, to advanced rendering of anatomical tracts, to more recent graph-based representations of functional connectivity data, many of the ways we have come to understand the human connectome are through the intuitive insight these visualizations enable. Nonetheless, several unresolved problems persist. For example, probabilistic trac...

  8. Visual evaluation of liver function with 99mTc-GSA scintigraphy. Interobserver variation and intraobserver variation

    We introduced a new imaging grade to evaluate liver function with 99mTc-GSA and studied its diagnostic value using interobserver variation and intraobserver variation. One hundred four patients with liver disease were injected 185 MBq/3 mg of 99mTc-GSA. Anterior images of cardiac blood-pool and liver at 5 min after injection were divided into four grades on the basis of following four categories. Faint cardiac blood-pool image, without clear demonstration of its peripheral boundary was classed in grade I; weaker cardiac blood-pool than liver was grade II; almost same appearance of blood-pool with liver was grade III and stronger blood-pool than liver was grade IV. Three radiologists reviewed the images independently. They followed the same process three months after initial evaluation. κ-Test was employed to evaluate the goodness of agreement. Three pairs in the first reading showed excellent interobserver agreement (0.88, mean κ-value) and another three pairs in the first and second reading also showed excellent intraobserver agreement (0.87, mean κ-value). Quantitative indices obtained from time-activity curves for blood-pool and liver showed significant differences across four groups. Plasma retention rate of indocyanine green also showed significant difference between grade II and grade III. Imaging grade possesses high intra- and interobserver agreement and provides a good discrimination for liver function. (author)

  9. Visual art and visual perception

    Koenderink, Jan J.

    2015-01-01

    Visual art and visual perception ‘Visual art’ has become a minor cul-de-sac orthogonal to THE ART of the museum directors and billionaire collectors. THE ART is conceptual, instead of visual. Among its cherished items are the tins of artist’s shit (Piero Manzoni, 1961, Merda d’Artista) “worth their weight in gold”. I perceive a metabletic (van den Berg, 1956) parallel to philosophy transforming itself into speculative logic games, and psychology going cognitive by freeing itself from phenomen...

  10. Neuron analysis of visual perception

    Chow, K. L.

    1980-01-01

    The receptive fields of single cells in the visual system of cat and squirrel monkey were studied investigating the vestibular input affecting the cells, and the cell's responses during visual discrimination learning process. The receptive field characteristics of the rabbit visual system, its normal development, its abnormal development following visual deprivation, and on the structural and functional re-organization of the visual system following neo-natal and prenatal surgery were also studied. The results of each individual part of each investigation are detailed.

  11. Visual Education

    Buhl, Mie; Flensborg, Ingelise

    2010-01-01

    The intrinsic breadth of various types of images creates new possibilities and challenges for visual education. The digital media have moved the boundaries between images and other kinds of modalities (e.g. writing, speech and sound) and have augmented the possibilities for integrating...... the learning potential of images and visuality from two perspectives: 1) The perspective of digital media which are assumed to form an increasing part of experience and communication from the use of internet, tv and mobile devices. 2) The perspective of culture where images and visualisations are assumed...... to emerge in the interlocutory space of a global visual repertoire and diverse local interpretations. The two perspectives represent challenges for future visual education which require visual competences, not only within the arts but also within the subjects of natural sciences, social sciences, languages...

  12. Representations of modality-specific affective processing for visual and auditory stimuli derived from functional magnetic resonance imaging data.

    Shinkareva, Svetlana V; Wang, Jing; Kim, Jongwan; Facciani, Matthew J; Baucom, Laura B; Wedell, Douglas H

    2014-07-01

    There is converging evidence that people rapidly and automatically encode affective dimensions of objects, events, and environments that they encounter in the normal course of their daily routines. An important research question is whether affective representations differ with sensory modality. This research examined the nature of the dependency of affect and sensory modality at a whole-brain level of analysis in an incidental affective processing paradigm. Participants were presented with picture and sound stimuli that differed in positive or negative valence in an event-related functional magnetic resonance imaging experiment. Global statistical tests, applied at a level of the individual, demonstrated significant sensitivity to valence within modality, but not valence across modalities. Modality-general and modality-specific valence hypotheses predict distinctly different multidimensional patterns of the stimulus conditions. Examination of lower dimensional representation of the data demonstrated separable dimensions for valence processing within each modality. These results provide support for modality-specific valence processing in an incidental affective processing paradigm at a whole-brain level of analysis. Future research should further investigate how stimulus-specific emotional decoding may be mediated by the physical properties of the stimuli. PMID:24302696

  13. Vision, fiction and depiction : the forms and functions of visuality in the novels of Jane Austen, Ann Radcliffe, Maria Edgeworth and Fanny Burney

    Volz, Jessica A.

    2014-01-01

    There are many factors that contributed to the proliferation of visual codes, metaphors and references to the gendered gaze in women’s fiction of the late-eighteenth and early-nineteenth centuries. This thesis argues that the visual details in women’s novels published between 1778 and 1815 are more significant than scholars have previously acknowledged. My analysis of the oeuvres of Jane Austen, Ann Radcliffe, Maria Edgeworth and Fanny Burney shows that visuality — the nexus between the v...

  14. Visual Impairment

    ... poorly lit spaces, and colors that seem faded. Diabetic retinopathy (pronounced: reh-ton-AH-pa-thee) occurs when ... that is likely to cause visual impairment, many treatments are available. Options may include eyeglasses, contact lenses, ...

  15. Visual cognition

    Pinker, S.

    1985-01-01

    This book consists of essays covering issues in visual cognition presenting experimental techniques from cognitive psychology, methods of modeling cognitive processes on computers from artificial intelligence, and methods of studying brain organization from neuropsychology. Topics considered include: parts of recognition; visual routines; upward direction; mental rotation, and discrimination of left and right turns in maps; individual differences in mental imagery, computational analysis and the neurological basis of mental imagery: componental analysis.

  16. Monocular visual ranging

    Witus, Gary; Hunt, Shawn

    2008-04-01

    The vision system of a mobile robot for checkpoint and perimeter security inspection performs multiple functions: providing surveillance video, providing high resolution still images, and providing video for semi-autonomous visual navigation. Mid-priced commercial digital cameras support the primary inspection functions. Semi-autonomous visual navigation is a tertiary function whose purpose is to reduce the burden of teleoperation and free the security personnel for their primary functions. Approaches to robot visual navigation require some form of depth perception for speed control to prevent the robot from colliding with objects. In this paper present the initial results of an exploration of the capabilities and limitations of using a single monocular commercial digital camera for depth perception. Our approach combines complementary methods in alternating stationary and moving behaviors. When the platform is stationary, it computes a range image from differential blur in the image stack collected at multiple focus settings. When the robot is moving, it extracts an estimate of range from the camera auto-focus function, and combines this with an estimate derived from angular expansion of a constellation of visual tracking points.

  17. The Effects of Ageing and Visual Field Loss on Pointing to Visual Targets

    Rubinstein, Nikki J.; Anderson, Andrew J.; Ma-Wyatt, Anna; Walland, Mark J.; McKendrick, Allison M.

    2014-01-01

    Purpose To investigate the effect of ageing on visuomotor function and subsequently evaluate the effect of visual field loss on such function in older adults. Methods Two experiments were performed: 1) to determine the effect of ageing on visual localisation and subsequent pointing precision, and 2) to determine the effect of visual field loss on these outcome measures. For Experiment 1, we measured visual localisation and pointing precision radially at visual eccentricities of 5, 10 and 15° ...

  18. The neuronal correlates of mirror therapy: A functional magnetic resonance imaging study on mirror-induced visual illusions of ankle movements.

    Guo, Feng; Xu, Qun; Abo Salem, Hassan M; Yao, Yihao; Lou, Jicheng; Huang, Xiaolin

    2016-05-15

    Recovery in stroke is mediated by neural plasticity. Mirror therapy is an effective method in the rehabilitation of stroke patients, but the mechanism is still obscure. To identify the neural networks associated with the effect of lower-limbs mirror therapy, we investigated a functional magnetic resonance imaging (fMRI) study of mirror-induced visual illusion of ankle movements. Five healthy controls and five left hemiplegic stroke patients performed tasks related to mirror therapy in the fMRI study. Neural activation was compared in a no-mirror condition and a mirror condition. All subjects in the experiment performed the task of flexing and extending the right ankle. In a mirror condition, movement of the left ankle was simulated by mirror reflection of right ankle movement. Changes in neural activation in response to mirror therapy were assessed both in healthy controls and stroke patients. We found strong activation of the motor cortex bilaterally in healthy controls, as well as significant activation of the ipsilateral sensorimotor cortex, the occipital gyrus, and the anterior prefrontal gyrus in stroke patients with respect to the non-mirror condition. We concluded that mirror therapy of ankle movements may induce neural activation of the ipsilesional sensorimotor cortex, and that cortical reorganization may be useful for motor rehabilitation in stroke. PMID:26972531

  19. Assessment of brain cell function using 123I-IMP SPECT of cerebral blood flow and visual evoked potential by photic stimulation in normal and demented elderly subjects

    Cerebral blood flow was quantitatively measured using 123I-IMP SPECT by photic stimulation and visual evoked potential (VEPs) in normal and dementia subjects: 8 with Alzheimer-type dementia, 9 with cerebrovascular dementia and 7 normal elderly subjects were divided into the three groups based on the Clinical Dementia Rating (CDR) grade: Group I (CDR 0), Group II (CDR 0.5-1), Group III (CDR 2-3). The 123I-IMP SPECT measurement was conducted at rest with the eyes closed and also during photic stimulation. VEPs were measured simultaneously. The results reveal prolongation of the P2 latency of the VEPs prolonged in accordance with the increasing severity of the dementia, and quantitative cerebral blood flow was lower in Group II and Group III than in Group I at rest, while during photic stimulation it significantly increased in Group I and II, but showed no change in Group III. The results suggest that quantitative measurement of cerebral blood flow using 123I-IMP SPECT by photic stimulation may enable more detailed assessment of brain cell function. (author)

  20. The visual representations of motion and of gravity are functionally independent: Evidence of a differential effect of smooth pursuit eye movements.

    De Sá Teixeira, Nuno Alexandre

    2016-09-01

    The memory for the final position of a moving object which suddenly disappears has been found to be displaced forward, in the direction of motion, and downwards, in the direction of gravity. These phenomena were coined, respectively, Representational Momentum and Representational Gravity. Although both these and similar effects have been systematically linked with the functioning of internal representations of physical variables (e.g. momentum and gravity), serious doubts have been raised for a cognitively based interpretation, favouring instead a major role of oculomotor and perceptual factors which, more often than not, were left uncontrolled and even ignored. The present work aims to determine the degree to which Representational Momentum and Representational Gravity are epiphenomenal to smooth pursuit eye movements. Observers were required to indicate the offset locations of targets moving along systematically varied directions after a variable imposed retention interval. Each participant completed the task twice, varying the eye movements' instructions: gaze was either constrained or left free to track the targets. A Fourier decomposition analysis of the localization responses was used to disentangle both phenomena. The results show unambiguously that constraining eye movements significantly eliminates the harmonic components which index Representational Momentum, but have no effect on Representational Gravity or its time course. The found outcomes offer promising prospects for the study of the visual representation of gravity and its neurological substrates. PMID:27106480

  1. Qualitative and quantitative measurement of brain activity associated with visual sexual arousal in males and females: 3.0 tesIa functional MR imaging

    The present study utilized 3.0 Tesla functional MR imaging to identify and quantify the activated brain regions associated with visually evoked sexual arousal, and also to discriminate the gender differences between the cortical activation patterns in response to sexual stimuli. A total of 24 healthy, right-handed volunteers, 14 males (mean age: 24) and 10 females (mean age: 23), with normal heterosexual function underwent functional MRI on a 3.0T MR scanner (Forte, Isole technique, Korea). The sexual stimulation consisted of a 1-minute rest with black screen, followed by a 3- minute stimulation by an erotic video film, and concluded with a 1-minute rest. The fMRI data was obtained from 20 slices (5 mm slice thickness, no gap) parallel to the AC-PC (anterior commissure and posterior commissure) line on the sagittal plane, giving a total of 2,100 images. The brain activation maps and the resulting quantification were analyzed by the statistical parametric mapping program, SPM 99. The mean-activated images were obtained from each individual activation map using one sampled t-test. The FALBA program, which is a new algorithm based on the pixel differentiation method, was used to identify and quantify the brain activation and lateralization indices with respect to the functional and anatomical terms. In both male and female volunteers, significant brain activation showed in the limbic areas of the parahippocampal gyrus, septal area, cingulate gyrus and thalamus. It is interesting to note that the septal areas gave a relatively lower activation ratio with high brain activities. On the contrary, the putamen, insula cortex, and corpus callosum gave a higher activation ratio with low brain activities. In particular, brain activation in the septal area, which was not reported in the previous fMRI studies under 1.5 Tesla, represents a distinct finding of this study using 3.0T MR scanner. The overall lateralization index of activation shows left predominance (LI= 35.3%) in

  2. Qualitative and quantitative measurement of brain activity associated with visual sexual arousal in males and females: 3.0 tesIa functional MR imaging

    Kim, Hyung Joong; Jeong, Gwang Woo; Eun, Sung Jong; Cho, Seong Hoon; Seo, Jeong Jin; Kang, Heoung Keun; Park, Kwang Sung [School of Medicine, Chonnam National Univ., Gwangju (Korea, Republic of)

    2004-08-01

    The present study utilized 3.0 Tesla functional MR imaging to identify and quantify the activated brain regions associated with visually evoked sexual arousal, and also to discriminate the gender differences between the cortical activation patterns in response to sexual stimuli. A total of 24 healthy, right-handed volunteers, 14 males (mean age: 24) and 10 females (mean age: 23), with normal heterosexual function underwent functional MRI on a 3.0T MR scanner (Forte, Isole technique, Korea). The sexual stimulation consisted of a 1-minute rest with black screen, followed by a 3- minute stimulation by an erotic video film, and concluded with a 1-minute rest. The fMRI data was obtained from 20 slices (5 mm slice thickness, no gap) parallel to the AC-PC (anterior commissure and posterior commissure) line on the sagittal plane, giving a total of 2,100 images. The brain activation maps and the resulting quantification were analyzed by the statistical parametric mapping program, SPM 99. The mean-activated images were obtained from each individual activation map using one sampled t-test. The FALBA program, which is a new algorithm based on the pixel differentiation method, was used to identify and quantify the brain activation and lateralization indices with respect to the functional and anatomical terms. In both male and female volunteers, significant brain activation showed in the limbic areas of the parahippocampal gyrus, septal area, cingulate gyrus and thalamus. It is interesting to note that the septal areas gave a relatively lower activation ratio with high brain activities. On the contrary, the putamen, insula cortex, and corpus callosum gave a higher activation ratio with low brain activities. In particular, brain activation in the septal area, which was not reported in the previous fMRI studies under 1.5 Tesla, represents a distinct finding of this study using 3.0T MR scanner. The overall lateralization index of activation shows left predominance (LI= 35.3%) in

  3. Changes in brain function and anatomical structure following treatment of hyperbaric oxygen for visual pathway abnormalities In 16 cases Evaluation of functional magnetic resonance Imaging combined with diffusion tensor imaging

    Ziqian Chen; Ping Ni; Hui Xiao; Jinhua Chen; Gennian Qian; Youqiang Ye; Shangwen Xu; Jinliang Wang; Xizhang Yang

    2008-01-01

    BACKGROUND:There is a growing research focus on the combination of blood oxygenation level dependent functional magnetic resonance imaging(BOLD-fMRI)and diffusion tensor imaging(DTI)to evaluate visual cortical function and structural changes in the cerebrum,as well as morphological changes to the white matter fiber tracks,after visual pathway lesions.However,the combined application of BOLD-fMRI and DTI in treating of visual pathway abnormalities still requires further studies. OBJECTIVE:To observe and evaluate the effects of hyperbaric oxygen on visual pathway abnormalities,and to evaluate the characteristics of cerebral function and anatomic structural changes by using BOLD-fMRI combined with DTI technique. DESIGN:Case contrast observation. SETTING:Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS:Sixteen patients(9 males and 7 females,15-77 years old)with lateral or bilateral visual disorder induced by visual pathway lesions were selected from the Department of Neurology,Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from January 2006 to May 2007.These patients comprised the lesion group.Measures of interventional therapy:hyperbaric oxygen of two normal atmospheres for three courses(10 d/course)and routine internal medicine treatment.In addition,12 healthy subjects of similar sex and age to the lesion group were regarded as the control group.The control group underwent routine ophthalmological and ocular fundus examinations; diagnostic results were normal. The experiment received confirmed consent from the local ethic committee,and all patients provided informed consent.METHODS:BOLD-fMRI and DTI manifestations in the lesion group were observed before and after hyperbaric oxygen intervention,and the results were compared with the control group.The subjects were positioned on their back,and BOLD-fMRI images were collected with the following GRE EPI sequence:TR= 2 000 ms,TE=40 ms,layer thickness=5 mm

  4. Restoration of visual function by expression of a light-gated mammalian ion channel in retinal ganglion cells or ON-bipolar cells.

    Gaub, Benjamin M; Berry, Michael H; Holt, Amy E; Reiner, Andreas; Kienzler, Michael A; Dolgova, Natalia; Nikonov, Sergei; Aguirre, Gustavo D; Beltran, William A; Flannery, John G; Isacoff, Ehud Y

    2014-12-23

    Most inherited forms of blindness are caused by mutations that lead to photoreceptor cell death but spare second- and third-order retinal neurons. Expression of the light-gated excitatory mammalian ion channel light-gated ionotropic glutamate receptor (LiGluR) in retinal ganglion cells (RGCs) of the retina degeneration (rd1) mouse model of blindness was previously shown to restore some visual functions when stimulated by UV light. Here, we report restored retinal function in visible light in rodent and canine models of blindness through the use of a second-generation photoswitch for LiGluR, maleimide-azobenzene-glutamate 0 with peak efficiency at 460 nm (MAG0(460)). In the blind rd1 mouse, multielectrode array recordings of retinal explants revealed robust and uniform light-evoked firing when LiGluR-MAG0(460) was targeted to RGCs and robust but diverse activity patterns in RGCs when LiGluR-MAG0(460) was targeted to ON-bipolar cells (ON-BCs). LiGluR-MAG0(460) in either RGCs or ON-BCs of the rd1 mouse reinstated innate light-avoidance behavior and enabled mice to distinguish between different temporal patterns of light in an associative learning task. In the rod-cone dystrophy dog model of blindness, LiGluR-MAG0(460) in RGCs restored robust light responses to retinal explants and intravitreal delivery of LiGluR and MAG0(460) was well tolerated in vivo. The results in both large and small animal models of photoreceptor degeneration provide a path to clinical translation. PMID:25489083

  5. ERP Evidence of Visualization at Early Stages of Visual Processing

    Page, Jonathan W.; Duhamel, Paul; Crognale, Michael A.

    2011-01-01

    Recent neuroimaging research suggests that early visual processing circuits are activated similarly during visualization and perception but have not demonstrated that the cortical activity is similar in character. We found functional equivalency in cortical activity by recording evoked potentials while color and luminance patterns were viewed and…

  6. Visual comparison for information visualization

    Gleicher, M.

    2011-09-07

    Data analysis often involves the comparison of complex objects. With the ever increasing amounts and complexity of data, the demand for systems to help with these comparisons is also growing. Increasingly, information visualization tools support such comparisons explicitly, beyond simply allowing a viewer to examine each object individually. In this paper, we argue that the design of information visualizations of complex objects can, and should, be studied in general, that is independently of what those objects are. As a first step in developing this general understanding of comparison, we propose a general taxonomy of visual designs for comparison that groups designs into three basic categories, which can be combined. To clarify the taxonomy and validate its completeness, we provide a survey of work in information visualization related to comparison. Although we find a great diversity of systems and approaches, we see that all designs are assembled from the building blocks of juxtaposition, superposition and explicit encodings. This initial exploration shows the power of our model, and suggests future challenges in developing a general understanding of comparative visualization and facilitating the development of more comparative visualization tools. © The Author(s) 2011.

  7. Assessment of visual function and retinal structure following acute light exposure in the light sensitive T4R rhodopsin mutant dog.

    Iwabe, Simone; Ying, Gui-Shuang; Aguirre, Gustavo D; Beltran, William A

    2016-05-01

    The effect of acute exposure to various intensities of white light on visual behavior and retinal structure was evaluated in the T4R RHO dog, a naturally-occurring model of autosomal dominant retinitis pigmentosa due to a mutation in the Rhodopsin gene. A total of 14 dogs (ages: 4-5.5 months) were used in this study: 3 homozygous mutant RHO(T4R/T4R), 8 heterozygous mutant RHO(T4R/+), and 3 normal wild-type (WT) dogs. Following overnight dark adaptation, the left eyes were acutely exposed to bright white light with a monocular Ganzfeld dome, while the contralateral right eye was shielded. Each of the 3 homozygous (RHO(T4R/T4R)) mutant dogs had a single unilateral light exposure (LE) to a different (low, moderate, and high) dose of white light (corneal irradiance/illuminance: 0.1 mW/cm(2), 170 lux; 0.5 mW/cm(2), 820 lux; or 1 mW/cm(2), 1590 lux) for 1 min. All 8 heterozygous (RHO(T4R/+)) mutant dogs were exposed once to the same moderate dose of light. The 3 WT dogs had their left eyes exposed 1, 2, or 3 times to the same highest dose of light. Visual function prior to LE and at 2 weeks and 33 weeks after exposure was objectively assessed in the RHO(T4R/T4R) and WT dogs by using an obstacle-avoidance course. Transit time through the obstacle course was measured under different scotopic to photopic ambient illuminations. Morphological retinal changes were evaluated by non-invasive in vivo cSLO/sdOCT imaging and histology before and at several time-points (2-36 weeks) after light exposure. The analysis of the transit time through the obstacle course showed that no differences were observed in any of mutant or WT dogs at 2 weeks and 33 weeks post LE. The RHO(T4R/T4R) retina exposed to the lowest dose of white light showed no obvious changes in ONL thickness at 2 weeks, but mild decrease was noted 36 weeks after LE. The RHO(T4R/T4R) retina that received a moderate dose (showed an obvious decrease in ONL thickness along the superior and temporal meridians at 2

  8. Visual cognition

    Pinker, S.

    1985-01-01

    This collection of research papers on visual cognition first appeared as a special issue of Cognition: International Journal of Cognitive Science. The study of visual cognition has seen enormous progress in the past decade, bringing important advances in our understanding of shape perception, visual imagery, and mental maps. Many of these discoveries are the result of converging investigations in different areas, such as cognitive and perceptual psychology, artificial intelligence, and neuropsychology. This volume is intended to highlight a sample of work at the cutting edge of this research area for the benefit of students and researchers in a variety of disciplines. The tutorial introduction that begins the volume is designed to help the nonspecialist reader bridge the gap between the contemporary research reported here and earlier textbook introductions or literature reviews.

  9. Visualizing Transformation

    Pedersen, Pia

    2012-01-01

    Transformation, defined as the step of extracting, arranging and simplifying data into visual form (M. Neurath, 1974), was developed in connection with ISOTYPE (International System Of TYpographic Picture Education) and might well be the most important legacy of Isotype to the field of graphic...... design. Recently transformation has attracted renewed interest because of the book ‘The Transformer’ written by Robin Kinross and Marie Neurath. My on-going research project, summarized in this paper, identifies and depicts the essential principles of data visualization underlying the process of...... transformation with reference to Marie Neurath’s sketches on the Bilston Project. The material has been collected at the Otto and Marie Neurath Collection housed at the University of Reading, UK. By using data visualization as a research method to look directly into the process of transformation the project...

  10. Neural mechanisms of recovery following early visual deprivation

    Mitchell, Donald E.; Sengpiel, Frank

    2008-01-01

    Natural patterned early visual input is essential for the normal development of the central visual pathways and the visual capacities they sustain. Without visual input, the functional development of the visual system stalls not far from the state at birth, and if input is distorted or biased the visual system develops in an abnormal fashion resulting in specific visual deficits. Monocular deprivation, an extreme form of biased exposure, results in large anatomical and physiological changes i...

  11. Nicotine effects on brain function during a visual oddball task: a comparison between conventional and EEG-informed fMRI analysis.

    Warbrick, Tracy; Mobascher, Arian; Brinkmeyer, Jürgen; Musso, Francesco; Stoecker, Tony; Shah, N Jon; Fink, Gereon R; Winterer, Georg

    2012-08-01

    In a previous oddball task study, it was shown that the inclusion of electrophysiology (EEG), that is, single-trial P3 ERP parameters, in the analysis of fMRI responses can detect activation that is not apparent with conventional fMRI data modeling strategies [Warbrick, T., Mobascher, A., Brinkmeyer, J., Musso, F., Richter, N., Stoecker, T., et al. Single-trial P3 amplitude and latency informed event-related fMRI models yield different BOLD response patterns to a target detection task. Neuroimage, 47, 1532-1544, 2009]. Given that P3 is modulated by nicotine, including P3 parameters in the fMRI analysis might provide additional information about nicotine effects on brain function. A 1-mg nasal nicotine spray (0.5 mg each nostril) or placebo (pepper) spray was administered in a double-blind, placebo-controlled, within-subject, randomized, cross-over design. Simultaneous EEG-fMRI and behavioral data were recorded from 19 current smokers in response to an oddball-type visual choice RT task. Conventional general linear model analysis and single-trial P3 amplitude informed general linear model analysis of the fMRI data were performed. Comparing the nicotine with the placebo condition, reduced RTs in the nicotine condition were related to decreased BOLD responses in the conventional analysis encompassing the superior parietal lobule, the precuneus, and the lateral occipital cortex. On the other hand, reduced RTs were related to increased BOLD responses in the precentral and postcentral gyri, and ACC in the EEG-informed fMRI analysis. Our results show how integrated analyses of simultaneous EEG-fMRI data can be used to detect nicotine effects that would not have been revealed through conventional analysis of either measure in isolation. This emphasizes the significance of applying multimodal imaging methods to pharmacoimaging. PMID:22452559

  12. Visual Impediments to Learning

    Noëlla Piquette, PhD

    2013-07-01

    Full Text Available Cognition, learning, and motor planning are dependent upon accurate encoding of stimuli from the environment. If there is an error in, or an impediment to, sensory perception, higher cognitive functions, such as reading, memory, emotional awareness, and impulse control can be affected. In schools, deficiencies of the visual process impede and impair reading acquisition and learning and influence other behavior. Children are affected by different types of functional impediments to eyesight and visual function. The degree to which children are impacted varies according to the depth and nature of the impediments present, and to some degree to socioeconomic status. Some children are at a greater disadvantage simply because of the greater visual demands of the neo-traditional classroom. These visual impediments to learning (VIL are rarely detected in common sight screenings and are associated with limited socioeconomic success and increased criminality. Significant VIL limit academic and life outcomes, with some ethnicities affected by a greater prevalence of reading-impairing impediments. This presents difficulties for various public agencies at all levels of government. To complicate matters further, children who are affected by vision difficulties will most often not report the problem, nor will VIL be detected during standard pediatric or psychoeducational assessment.VIL are described in brief, as is how they alter children’s academic outcomes, health, and behavior. A model of sufficient vision care in the prevention and management of most vision-related learning and behavioral difficulties is proposed. The position is advanced that ensuring a

  13. A Content Analysis of Visuals Used in Print Media Advertising.

    Moriarty, Sandra E.

    1987-01-01

    Provides a content analysis of advertising visuals--illustrations and photographs--to determine the frequency with which the basic visual communication functions are used. Finds that photographs are the most frequently used type of visual and that symbolic visuals are more prevalent than literal visuals. (MM)

  14. Multimodal brain visualization

    Nadeem, Saad; Kaufman, Arie

    2016-03-01

    Current connectivity diagrams of human brain image data are either overly complex or overly simplistic. In this work we introduce simple yet accurate interactive visual representations of multiple brain image structures and the connectivity among them. We map cortical surfaces extracted from human brain magnetic resonance imaging (MRI) data onto 2D surfaces that preserve shape (angle), extent (area), and spatial (neighborhood) information for 2D (circular disk) and 3D (spherical) mapping, split these surfaces into separate patches, and cluster functional and diffusion tractography MRI connections between pairs of these patches. The resulting visualizations are easier to compute on and more visually intuitive to interact with than the original data, and facilitate simultaneous exploration of multiple data sets, modalities, and statistical maps.

  15. Teach yourself visually Adobe Muse

    Huddleston, Rob

    2012-01-01

    A visual learner's guide to creating beautiful, functional websites without writing a line of code Adobe Muse allows graphic and visual designers to leverage the skills they already have in graphic design programs such as Adobe InDesign to create engaging, visually stunning websites without needing to write code. Veteran web designers as well as those new to website creation will learn to outline what a site needs and who it serves, as well as all about generating a look and feel, implementing the design as a working page, testing functionality, taking the site live, and keeping it goi

  16. Are visual peripheries forever young?

    Burnat, Kalina

    2015-01-01

    The paper presents a concept of lifelong plasticity of peripheral vision. Central vision processing is accepted as critical and irreplaceable for normal perception in humans. While peripheral processing chiefly carries information about motion stimuli features and redirects foveal attention to new objects, it can also take over functions typical for central vision. Here I review the data showing the plasticity of peripheral vision found in functional, developmental, and comparative studies. Even though it is well established that afferent projections from central and peripheral retinal regions are not established simultaneously during early postnatal life, central vision is commonly used as a general model of development of the visual system. Based on clinical studies and visually deprived animal models, I describe how central and peripheral visual field representations separately rely on early visual experience. Peripheral visual processing (motion) is more affected by binocular visual deprivation than central visual processing (spatial resolution). In addition, our own experimental findings show the possible recruitment of coarse peripheral vision for fine spatial analysis. Accordingly, I hypothesize that the balance between central and peripheral visual processing, established in the course of development, is susceptible to plastic adaptations during the entire life span, with peripheral vision capable of taking over central processing. PMID:25945262

  17. Sensitive Visual Detection of AHPND Bacteria Using Loop-Mediated Isothermal Amplification Combined with DNA-Functionalized Gold Nanoparticles as Probes.

    Arunrut, Narong; Kampeera, Jantana; Sirithammajak, Sarawut; Sanguanrut, Piyachat; Proespraiwong, Porranee; Suebsing, Rungkarn; Kiatpathomchai, Wansika

    2016-01-01

    Acute hepatopancreatic necrosis disease (AHPND) is a component cause of early mortality syndrome (EMS) of shrimp. In 2013, the causative agent was found to be unique isolates of Vibrio parahaemolyticus (VPAHPND) that contained a 69 kbp plasmid (pAP1) carrying binary Pir-like toxin genes PirvpA and PirvpB. In Thailand, AHPND was first recognized in 2012, prior to knowledge of the causative agent, and it subsequently led to a precipitous drop in shrimp production. After VPAHPND was characterized, a major focus of the AHPND control strategy was to monitor broodstock shrimp and post larvae for freedom from VPAHPND by nucleic acid amplification methods, most of which required use of expensive and sophisticated equipment not readily available in a shrimp farm setting. Here, we describe a simpler but equally sensitive approach for detection of VPAHPND based on loop-mediated isothermal amplification (LAMP) combined with unaided visual reading of positive amplification products using a DNA-functionalized, ssDNA-labled nanogold probe (AuNP). The target for the special set of six LAMP primers used was the VPAHPND PirvpA gene. The LAMP reaction was carried out at 65°C for 45 min followed by addition of the red AuNP solution and further incubation at 65°C for 5 min, allowing any PirvpA gene amplicons present to hybridize with the probe. Hybridization protected the AuNP against aggregation, so that the solution color remained red upon subsequent salt addition (positive test result) while unprotected AuNP aggregated and underwent a color change from red to blue and eventually precipitated (negative result). The total assay time was approximately 50 min. The detection limit (100 CFU) was comparable to that of other commonly-used methods for nested PCR detection of VPAHPND and 100-times more sensitive than 1-step PCR detection methods (104 CFU) that used amplicon detection by electrophoresis or spectrophotometry. There was no cross reaction with DNA templates derived from non

  18. Sensitive Visual Detection of AHPND Bacteria Using Loop-Mediated Isothermal Amplification Combined with DNA-Functionalized Gold Nanoparticles as Probes

    Arunrut, Narong; Kampeera, Jantana; Sirithammajak, Sarawut; Sanguanrut, Piyachat; Proespraiwong, Porranee; Suebsing, Rungkarn; Kiatpathomchai, Wansika

    2016-01-01

    Acute hepatopancreatic necrosis disease (AHPND) is a component cause of early mortality syndrome (EMS) of shrimp. In 2013, the causative agent was found to be unique isolates of Vibrio parahaemolyticus (VPAHPND) that contained a 69 kbp plasmid (pAP1) carrying binary Pir-like toxin genes PirvpA and PirvpB. In Thailand, AHPND was first recognized in 2012, prior to knowledge of the causative agent, and it subsequently led to a precipitous drop in shrimp production. After VPAHPND was characterized, a major focus of the AHPND control strategy was to monitor broodstock shrimp and post larvae for freedom from VPAHPND by nucleic acid amplification methods, most of which required use of expensive and sophisticated equipment not readily available in a shrimp farm setting. Here, we describe a simpler but equally sensitive approach for detection of VPAHPND based on loop-mediated isothermal amplification (LAMP) combined with unaided visual reading of positive amplification products using a DNA-functionalized, ssDNA-labled nanogold probe (AuNP). The target for the special set of six LAMP primers used was the VPAHPND PirvpA gene. The LAMP reaction was carried out at 65°C for 45 min followed by addition of the red AuNP solution and further incubation at 65°C for 5 min, allowing any PirvpA gene amplicons present to hybridize with the probe. Hybridization protected the AuNP against aggregation, so that the solution color remained red upon subsequent salt addition (positive test result) while unprotected AuNP aggregated and underwent a color change from red to blue and eventually precipitated (negative result). The total assay time was approximately 50 min. The detection limit (100 CFU) was comparable to that of other commonly-used methods for nested PCR detection of VPAHPND and 100-times more sensitive than 1-step PCR detection methods (104 CFU) that used amplicon detection by electrophoresis or spectrophotometry. There was no cross reaction with DNA templates derived from non

  19. Cross-Modal and Intra-Modal Characteristics of Visual Function and Speech Perception Performance in Postlingually Deafened, Cochlear Implant Users

    Kim, Min-Beom; Shim, Hyun-Yong; Jin, Sun Hwa; Kang, Soojin; Woo, Jihwan; Han, Jong Chul; Lee, Ji Young; Kim, Martha; Cho, Yang-Sun

    2016-01-01

    Evidence of visual-auditory cross-modal plasticity in deaf individuals has been widely reported. Superior visual abilities of deaf individuals have been shown to result in enhanced reactivity to visual events and/or enhanced peripheral spatial attention. The goal of this study was to investigate the association between visual-auditory cross-modal plasticity and speech perception in post-lingually deafened, adult cochlear implant (CI) users. Post-lingually deafened adults with CIs (N = 14) and a group of normal hearing, adult controls (N = 12) participated in this study. The CI participants were divided into a good performer group (good CI, N = 7) and a poor performer group (poor CI, N = 7) based on word recognition scores. Visual evoked potentials (VEP) were recorded from the temporal and occipital cortex to assess reactivity. Visual field (VF) testing was used to assess spatial attention and Goldmann perimetry measures were analyzed to identify differences across groups in the VF. The association of the amplitude of the P1 VEP response over the right temporal or occipital cortex among three groups (control, good CI, poor CI) was analyzed. In addition, the association between VF by different stimuli and word perception score was evaluated. The P1 VEP amplitude recorded from the right temporal cortex was larger in the group of poorly performing CI users than the group of good performers. The P1 amplitude recorded from electrodes near the occipital cortex was smaller for the poor performing group. P1 VEP amplitude in right temporal lobe was negatively correlated with speech perception outcomes for the CI participants (r = -0.736, P = 0.003). However, P1 VEP amplitude measures recorded from near the occipital cortex had a positive correlation with speech perception outcome in the CI participants (r = 0.775, P = 0.001). In VF analysis, CI users showed narrowed central VF (VF to low intensity stimuli). However, their far peripheral VF (VF to high intensity stimuli) was

  20. Cross-Modal and Intra-Modal Characteristics of Visual Function and Speech Perception Performance in Postlingually Deafened, Cochlear Implant Users.

    Min-Beom Kim

    Full Text Available Evidence of visual-auditory cross-modal plasticity in deaf individuals has been widely reported. Superior visual abilities of deaf individuals have been shown to result in enhanced reactivity to visual events and/or enhanced peripheral spatial attention. The goal of this study was to investigate the association between visual-auditory cross-modal plasticity and speech perception in post-lingually deafened, adult cochlear implant (CI users. Post-lingually deafened adults with CIs (N = 14 and a group of normal hearing, adult controls (N = 12 participated in this study. The CI participants were divided into a good performer group (good CI, N = 7 and a poor performer group (poor CI, N = 7 based on word recognition scores. Visual evoked potentials (VEP were recorded from the temporal and occipital cortex to assess reactivity. Visual field (VF testing was used to assess spatial attention and Goldmann perimetry measures were analyzed to identify differences across groups in the VF. The association of the amplitude of the P1 VEP response over the right temporal or occipital cortex among three groups (control, good CI, poor CI was analyzed. In addition, the association between VF by different stimuli and word perception score was evaluated. The P1 VEP amplitude recorded from the right temporal cortex was larger in the group of poorly performing CI users than the group of good performers. The P1 amplitude recorded from electrodes near the occipital cortex was smaller for the poor performing group. P1 VEP amplitude in right temporal lobe was negatively correlated with speech perception outcomes for the CI participants (r = -0.736, P = 0.003. However, P1 VEP amplitude measures recorded from near the occipital cortex had a positive correlation with speech perception outcome in the CI participants (r = 0.775, P = 0.001. In VF analysis, CI users showed narrowed central VF (VF to low intensity stimuli. However, their far peripheral VF (VF to high intensity

  1. Neural Anatomy of Primary Visual Cortex Limits Visual Working Memory.

    Bergmann, Johanna; Genç, Erhan; Kohler, Axel; Singer, Wolf; Pearson, Joel

    2016-01-01

    Despite the immense processing power of the human brain, working memory storage is severely limited, and the neuroanatomical basis of these limitations has remained elusive. Here, we show that the stable storage limits of visual working memory for over 9 s are bound by the precise gray matter volume of primary visual cortex (V1), defined by fMRI retinotopic mapping. Individuals with a bigger V1 tended to have greater visual working memory storage. This relationship was present independently for both surface size and thickness of V1 but absent in V2, V3 and for non-visual working memory measures. Additional whole-brain analyses confirmed the specificity of the relationship to V1. Our findings indicate that the size of primary visual cortex plays a critical role in limiting what we can hold in mind, acting like a gatekeeper in constraining the richness of working mental function. PMID:25100854

  2. Correlation between single-trial visual evoked potentials and the blood oxygenation level dependent response in simultaneously recorded electroencephalography-functional magnetic resonance imaging

    Fuglø, Dan; Pedersen, Henrik; Rostrup, Egill;

    2012-01-01

    dependent variations in different occipital and extraoccipital cortical areas not explained by the boxcar regressor. The results suggest that the P1-N2 regressor is the best EEG-based regressor to model the visual paradigm, but when looking for additional effects like habituation or attention modulation...

  3. Effectiveness of rehabilitation interventions in improving emotional and functional status in hearing or visually impaired older adults : a systematic review with meta-analyses

    Roets-Merken, Lieve M.; Draskovic, Irena; Zuidema, Sytse U.; van Erp, Willemijn S.; Graff, Maud J. L.; Kempen, Gertrudis I. J. M.; Vernooij-Dassen, Myrra J. F. J.

    2015-01-01

    Objective: To assess the effectiveness of non-equipment based rehabilitation interventions for older adults with an age-related hearing or visual impairment. Data sources: We searched PubMed, EMBASE, PsychInfo, CINAHL, and the Cochrane Central Register of Controlled Trials. Review methods: Two autho

  4. Effectiveness of rehabilitation interventions in improving emotional and functional status in hearing or visually impaired older adults: a systematic review with meta-analyses

    Roets-Merken, L.M.; Draskovic, I.; Zuidema, S.U.; Erp, W.S. van; Graff, M.J.L.; Kempen, G.I.; Vernooij-Dassen, M.J.F.J.

    2015-01-01

    OBJECTIVE: To assess the effectiveness of non-equipment based rehabilitation interventions for older adults with an age-related hearing or visual impairment. DATA SOURCES: We searched PubMed, EMBASE, PsychInfo, CINAHL, and the Cochrane Central Register of Controlled Trials. REVIEW METHODS: Two autho

  5. Visual Cortex Plasticity Following Peripheral Damage To The Visual System: fMRI Evidence.

    Lemos, João; Pereira, Daniela; Castelo-Branco, Miguel

    2016-10-01

    Over the last two decades, functional magnetic resonance imaging (fMRI) has become a powerful research method to investigate cortical visual plasticity. Abnormal fMRI response patterns have been occasionally detected in the visually deprived cortex of patients with bilateral retinal diseases. Controversy remains whether these observations indicate structural reorganization of the visual cortex or unmasking of previously silent cortico-cortical connections. In optic nerve diseases, there is weak evidence showing that early visual cortex seems to lack reorganization, while higher-order visual areas undergo plastic changes which may contribute to optimise visual function. There is however accumulating imaging evidence demonstrating trans-synaptic degeneration of the visual cortex in patients with disease of the anterior visual pathways. This may preclude the use of restorative treatments in these patients. Here, we review and update the body of fMRI evidence on visual cortical plasticity. PMID:27542799

  6. Probing neuronal activation by functional quantitative susceptibility mapping under a visual paradigm: A group level comparison with BOLD fMRI and PET.

    Özbay, Pinar Senay; Warnock, Geoffrey; Rossi, Cristina; Kuhn, Felix; Akin, Burak; Pruessmann, Klaas Paul; Nanz, Daniel

    2016-08-15

    Dynamic changes of brain-tissue magnetic susceptibility provide the basis for functional MR imaging (fMRI) via T2*-weighted signal-intensity modulations. Promising initial work on a detection of neuronal activity via quantitative susceptibility mapping (fQSM) has been published but consistently reported on ill-understood positive and negative activation patterns (Balla et al., 2014; Chen and Calhoun, 2015a). We set out to (i) demonstrate that fQSM can exploit established fMRI data acquisition and processing methods and to (ii) better describe aspects of the apparent activation patterns using fMRI and PET as standards of reference. Under a standardized visual-stimulation paradigm PET and 3-T gradient-echo EPI-based fQSM, fMRI data from 9 healthy volunteers were acquired and analyzed by means of Independent Component Analysis (ICA) at subject level and, for the first time, at group level. Numbers of activated (z-score>2.0) voxels were counted and their mean z-scores calculated in volumes of interest (occipital lobe (Nocc_lobe), segmented occipital gray-matter (NGM_occ_lobe), large veins (Nveins)), and in occipital-lobe voxels commonly activated in fQSM and fMRI component maps. Common but not entirely congruent regions of apparent activation were found in the occipital lobe in z-score maps from all modalities, fQSM, fMRI and PET, with distinct BOLD-negatively correlated regions in fQSM data. At subject-level, Nocc_lobe, NGM_occ_lobe and their mean z-scores were significantly smaller in fQSM than in fMRI, but their ratio, NGM_occ_lobe/Nocc_lobe, was comparable. Nveins did not statistically differ and the ratio Nveins/NGM_occ_lobe as well as the mean z-scores were higher for fQSM than for fMRI. In veins and immediate vicinity, z-score maps derived from both phase and fQSM-data showed positive and negative lobes resembling dipole shapes in simulated field and phase maps with no correlate in fMRI or PET data. Our results show that standard fMRI tools can directly be used

  7. The orbit and visual system

    The visual system represents an intricately organized and important region of the central nervous system. This system has critical sensory and motor functional components that are commonly affected by a wide variety of neurological diseases, and is frequently the specified region of interest on magnetic resonance imaging (MRI) examinations. It is therefore essential for the neuroradiologist to have a working knowledge of this system's anatomy, physiology, and pathology. This paper covers three general areas of the visual system that can be involved with pathologic processes often manifested on MRI: lesions of the globe and orbit, gaze disorders, and abnormalities affecting the visual fields

  8. Teach yourself visually Apple Watch

    Hart-Davis, Guy

    2015-01-01

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

  9. Visual Grouping by Neural Oscillators

    Yu, Guoshen

    2008-01-01

    Distributed synchronization is known to occur at several scales in the brain, and has been suggested as playing a key functional role in perceptual grouping. State-of-the-art visual grouping algorithms, however, seem to give comparatively little attention to neural synchronization analogies. Based on the framework of concurrent synchronization of dynamic systems, simple networks of neural oscillators coupled with diffusive connections are proposed to solve visual grouping problems. Multi-layer algorithms and feedback mechanisms are also studied. The same algorithm is shown to achieve promising results on several classical visual grouping problems, including point clustering, contour integration and image segmentation.

  10. Germanene-like defects in amorphous germanium revealed by three-dimensional visualization of high-resolution pair-distribution functions

    Tomberli, B.; Rahemtulla, A.; Kim, E.; Roorda, S.; Kycia, S.

    2015-08-01

    The structural description of even the most basic monatomic amorphous materials is under considerable debate. In this work, an intuitive computational technique has been developed to construct three-dimensional statistical density maps to directly visualize local atomic structure of amorphous germanium (a-Ge), enabling the interpretation of recent state-of-the-art experiments and simulations. The continuous random network (CRN) model is compared to our experimental model refined through a Reverse Monte Carlo routine. In this refinement a-Ge has two dominant structures: a fourfold coordinated tetrahedron and a buckled threefold coordinated local structure similar to silicene and germanene. These structures account for 95.7% of the total atoms in a 5:2 ratio respectively. Our method shows well defined structural ordering in the second shell of a-Ge. This novel visualization tool enables the interpretation of complex disordered materials and reveals the bimodal structures of a-Ge.

  11. Comparação da função visual e do índice de qualidade de vida com uso de óculos ou de lente de contato progressiva Comparative analysis of visual function and the quality of life index with eyeglasses or a progressive contact lens

    Neusa Vidal Sant'Anna

    2006-06-01

    Full Text Available OBJETIVO: Comparar a função visual e a resposta dos pacientes ao índice de qualidade de vida quando estes são corrigidos com óculos com lentes progressivas ou lente de contato progressiva. MÉTODOS: Foram selecionados 35 pacientes présbitas, usuários de óculos com acuidade visual igual, ou melhor, a logMAR zero (longe e J1 (perto, para adaptarem a lente de contato Focus Progressive®. Foram comparadas medidas de acuidade visual para longe, perto e sensibilidade ao contraste com a lente de contato e com os óculos. Os resultados do questionário de avaliação de qualidade de vida NEI VFQ-25 dos mesmos pacientes corrigidos com os óculos e com a lente de contato progressiva foram comparados, levando-se em consideração o tipo de ametropia e a idade. RESULTADOS: A acuidade visual para longe, perto e a sensibilidade ao contraste foram significantemente piores com lente de contato progressiva do que com os óculos. As respostas do questionário não diferiram quanto à forma de correção quando se analisou o tipo de ametropia, entretanto foram significantemente piores com a lente de contato nos grupos míope e hipermétrope abaixo das suas respectivas medianas da idade e maiores no hipermétrope acima de sua mediana. CONCLUSÃO: As funções visuais foram significantemente piores com a lente de contato e o tipo de ametropia não influenciou nas respostas ao índice de qualidade de vida quanto à forma de correção, mas sim, quanto à idade.PURPOSE: To compare the visual function and the answers to a questionnaire of quality of life of patients wearing a progressive contact lens or eyeglasses. METHODS: The Focus Progressive® contact lens had been fitted in 35 patients with far visual acuity with progressive-addition eyeglasses equal to zero (log MAR and near J1 (Jaeger. The far and near visual acuities and the measurement of contrast sensitivity were compared when the patients were wearing the eyeglasses or the contact lens and the

  12. Effects of heavy ions on the visual functions and electrophysiology of rodents: the ALTEA-MICE study ALTEA-MICE TEAM 02064 Retrieving of surface parameters over the tibetan plateau with microwave remote sensing

    Wang, J.; Gao, F.; Li, X.

    ALTEA-MICE is a multidisciplinary international project sponsored by NASA and by the Italian Space Agency (ASI) and Institute of Nuclear Physics (INFN) to investigate the effects of heavy ions on the visual system of mice. Both normal and mutant mice with gene defects affecting photoreceptor or bipolar cell function will be studied, with the scientific focus spanning from in vitro models to in vivo approaches and from cell to system physiology. Experiments are being performed at the Brookhaven National Laboratories with application of standardized electrophysiological techniques. The retina and visual cortex of adult mice and in vitro (retinal or cortical) cell preparations are radiated with short (2-5 msec) bursts of heavy (e.g. Silicon) ions, delivered by a collimated 3 mm beam. Mice are anesthetized and implanted with chronic electrodes in the visual cortex during pulsed radiation. Preliminary experiments performed with the GSI accelerator (Darmstadt, FRG) allow to record transient electrophysiological responses of the mouse visual cortex to bursts of particles in an order of magnitude of ~2 GeV, comparable to an energy loss of a bragging Fe in the eye, with 100-350 ms latency from pulsed radiation. The study protocol, experimental set-up, and preliminary results will be presented. Results from the GSI and BNL study will be outlined. The ALTEA -MICE project is expected to provide the scientific background needed to supplement the ALTEA project on astronauts and to yield information about the (electrophysiological correlates) of the functional brain impairment eventually induced by heavy ions in specific instances (e.g. during long-term operations in microgravity).

  13. Visualization of Tensor Fields Using Superquadric Glyphs

    Ennis, Daniel B.; Kindlman, Gordon; Rodriguez, Ignacio; Helm, Patrick A.; Mcveigh, Elliot R.

    2005-01-01

    The spatially varying tensor fields that arise in magnetic resonance imaging are difficult to visualize due to the multivariate nature of the data. To improve the understanding of myocardial structure and function a family of objects called glyphs, derived from superquadric parametric functions, are used to create informative and intuitive visualizations of the tensor fields. The superquadric glyphs are used to visualize both diffusion and strain tensors obtained in canine myocardium. The eig...

  14. Ultrascale Visualization of Climate Data

    Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bremer, Peer-Timo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Doutriaux, Charles [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Patchett, John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Williams, Sean [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Shipman, Galen M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, Ross G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pugmire, Dave [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smith, Brian E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Steed, Chad A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bethel, E. Wes [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Childs, Hank [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Krishnan, Harinarayan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Silva, Claudio T. [New York University, New York, NY (United States). Center for Urban Sciences; Santos, Emanuele [Universidade Federal do Ceara, Ceara (Brazil); Koop, David [New York University, New York, NY (United States); Ellqvist, Tommy [New York University, New York, NY (United States); Poco, Jorge [Polytechnic Institute of New York University, New York, NY (United States); Geveci, Berk [Kitware Inc., Clifton Park, NY (United States); Chaudhary, Aashish [Kitware Inc., Clifton Park, NY (United States); Bauer, Andy [Kitware Inc., Clifton Park, NY (United States); Pletzer, Alexander [Tech-X Corporation, Boulder, CO (United States); Kindig, Dave [Tech-X Corporation, Boulder, CO (United States); Potter, Gerald [National Aeronautics and Space Administration (NASA), Washington, DC (United States); Maxwell, Thomas P. [National Aeronautics and Space Administration (NASA), Washington, DC (United States)

    2013-09-01

    To support interactive visualization and analysis of complex, large-scale climate data sets, UV-CDAT integrates a powerful set of scientific computing libraries and applications to foster more efficient knowledge discovery. Connected through a provenance framework, the UV-CDAT components can be loosely coupled for fast integration or tightly coupled for greater functionality and communication with other components. This framework addresses many challenges in the interactive visual analysis of distributed large-scale data for the climate community.

  15. Visualization rhetoric: framing effects in narrative visualization.

    Hullman, Jessica; Diakopoulos, Nicholas

    2011-12-01

    Narrative visualizations combine conventions of communicative and exploratory information visualization to convey an intended story. We demonstrate visualization rhetoric as an analytical framework for understanding how design techniques that prioritize particular interpretations in visualizations that "tell a story" can significantly affect end-user interpretation. We draw a parallel between narrative visualization interpretation and evidence from framing studies in political messaging, decision-making, and literary studies. Devices for understanding the rhetorical nature of narrative information visualizations are presented, informed by the rigorous application of concepts from critical theory, semiotics, journalism, and political theory. We draw attention to how design tactics represent additions or omissions of information at various levels-the data, visual representation, textual annotations, and interactivity-and how visualizations denote and connote phenomena with reference to unstated viewing conventions and codes. Classes of rhetorical techniques identified via a systematic analysis of recent narrative visualizations are presented, and characterized according to their rhetorical contribution to the visualization. We describe how designers and researchers can benefit from the potentially positive aspects of visualization rhetoric in designing engaging, layered narrative visualizations and how our framework can shed light on how a visualization design prioritizes specific interpretations. We identify areas where future inquiry into visualization rhetoric can improve understanding of visualization interpretation. PMID:22034342

  16. Visual cortical excitability in dementia with Lewy bodies.

    Taylor, John-Paul; Firbank, Michael; O'Brien, John T

    2016-05-01

    Alterations in the visual system may underlie visual hallucinations in dementia with Lewy bodies (DLB). However, cortical excitability as measured by transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) activation of lower visual areas (V1-3) to visual stimuli appear normal in DLB. We explored the relationship between TMS-determined phosphene threshold and fMRI-related visual activation and found a positive relationship between the two in controls but a negative one in DLB. This double dissociation suggests a loss of inhibition in the visual system in DLB, which may predispose individuals to visual dysfunction and visual hallucinations. PMID:26541688

  17. Prism therapy and visual rehabilitation in homonymous visual field loss.

    O'Neill, Evelyn C

    2012-02-01

    PURPOSE: Homonymous visual field defects (HVFD) are common and frequently occur after cerebrovascular accidents. They significantly impair visual function and cause disability particularly with regard to visual exploration. The purpose of this study was to assess a novel interventional treatment of monocular prism therapy on visual functioning in patients with HVFD of varied etiology using vision targeted, health-related quality of life (QOL) questionnaires. Our secondary aim was to confirm monocular and binocular visual field expansion pre- and posttreatment. METHODS: Twelve patients with acquired, documented HVFD were eligible to be included. All patients underwent specific vision-targeted, health-related QOL questionnaire and monocular and binocular Goldmann perimetry before commencing prism therapy. Patients were fitted with monocular prisms on the side of the HVFD with the base-in the direction of the field defect creating a peripheral optical exotropia and field expansion. After the treatment period, QOL questionnaires and perimetry were repeated. RESULTS: Twelve patients were included in the treatment group, 10 of whom were included in data analysis. Overall, there was significant improvement within multiple vision-related, QOL functioning parameters, specifically within the domains of general health (p < 0.01), general vision (p < 0.05), distance vision (p < 0.01), peripheral vision (p < 0.05), role difficulties (p < 0.05), dependency (p < 0.05), and social functioning (p < 0.05). Visual field expansion was shown when measured monocularly and binocularly during the study period in comparison with pretreatment baselines. CONCLUSIONS: Patients with HVFD demonstrate decreased QOL. Monocular sector prisms can improve the QOL and expand the visual field in these patients.

  18. In vivo targeted magnetic resonance imaging and visualized photodynamic therapy in deep-tissue cancers using folic acid-functionalized superparamagnetic-upconversion nanocomposites

    Zeng, Leyong; Luo, Lijia; Pan, Yuanwei; Luo, Song; Lu, Guangming; Wu, Aiguo

    2015-05-01

    Multifunctional nanoprobes used in magnetic resonance imaging (MRI) and photodynamic therapy (PDT) also have potential applications in diagnosis and visualized therapy of cancers, and hence it is important to investigate the active-targeting ability and in vivo reliability of these nanoprobes. In this work, folic acid (FA)-targeted, photosensitizer (PS)-loaded Fe3O4@NaYF4:Yb/Er (FA-NPs-PS) nanocomposites were synthesized for in vivo T2-weighted MRI and visualized PDT of cancers by modeling MCF-7 tumor-bearing nude mice. By measuring the upconversion luminescence (UCL) and fluorescence emission spectra, the as-prepared FA-NPs-PS nanocomposites showed near-infrared (NIR)-triggered PDT performance due to the production of a singlet oxygen species. Moreover, by tracing PS fluorescence in MCF-7, HeLa cells and in MCF-7 tumors, the FA-targeted nanocomposites demonstrated good targeting ability both in vitro and in vivo. Under the irradiation of a 980 nm laser, the viabilities of MCF-7 and HeLa cells incubated with FA-NPs-PS nanocomposites could decrease to about 18.4% and 30.7%, respectively, and the inhibition of MCF-7 tumors could reach about 94.9%. The transverse MR relaxivity of 63.79 mM-1 s-1 (r2 value) and in vivo MR imaging of MCF-7 tumors indicated an excellent T2-weighted MR performance. This work demonstrated that FA-targeted MRI/PDT nanoprobes are effective for in vivo diagnosis and visualized therapy of breast cancers.Multifunctional nanoprobes used in magnetic resonance imaging (MRI) and photodynamic therapy (PDT) also have potential applications in diagnosis and visualized therapy of cancers, and hence it is important to investigate the active-targeting ability and in vivo reliability of these nanoprobes. In this work, folic acid (FA)-targeted, photosensitizer (PS)-loaded Fe3O4@NaYF4:Yb/Er (FA-NPs-PS) nanocomposites were synthesized for in vivo T2-weighted MRI and visualized PDT of cancers by modeling MCF-7 tumor-bearing nude mice. By measuring the

  19. The research on visual global and local cognitive functions of patients with Parkinson's disease%帕金森病患者视学整体与局部认知工能研究

    陈海波; 李淑华; 韩世辉; 王新德

    2002-01-01

    Objective To study visual global and local cognitive functions in the patients with Parkinson's disease(PD).Methods The visual cognitive software,which was devised by the Cognition Laboratory of National Science and Technology University,was used.30 PD patients and 31 normal controls(NC) were enrolled in the study.Result No significant difference on reaction time(RT) of visual global and local processing was found between PD patients and NC.Furthermore,the PD patients were divided into two groups:left side onset(LPD) and right side onset(RPD).The RT was longer in PD than in NC and RT was shorter in RPD than in NC.But there were no significant differences between PD patients and NC except global processing(big and small arrows at the same direction) in LPD.The RT was significantly longer in LPD than in RPD except local processing(big and small arrows at different direction)(P< 0.05).Conclusion The present study indicates that right basal ganglion might play a role in global and local processing and left basal ganglia might modulate(inhibit) the processing activity of right side.

  20. Why Teach Visual Culture?

    Passmore, Kaye

    2007-01-01

    Visual culture is a hot topic in art education right now as some teachers are dedicated to teaching it and others are adamant that it has no place in a traditional art class. Visual culture, the author asserts, can include just about anything that is visually represented. Although people often think of visual culture as contemporary visuals such…

  1. Insensitivity of visual short-term memory to irrelevant visual information

    Andrade, Jackie; Kemps, Eva; Werniers, Yves; May, Jon; Szmalec, Arnaud

    2002-01-01

    Several authors have hypothesised that visuo-spatial working memory is functionally analogous to verbal working memory. Irrelevant background speech impairs verbal short-term memory. We investigated whether irrelevant visual information has an analogous effect on visual short-term memory, using a dynamic visual noise (DVN) technique known to disrupt visual imagery (Quinn & McConnell, 1996a). Experiment 1 replicated the effect of DVN on pegword imagery. Experiments 2 and 3 showed no effect of ...

  2. Quality of Visual Cue Affects Visual Reweighting in Quiet Standing

    Moraes, Renato; de Freitas, Paulo Barbosa; Razuk, Milena; Barela, José Angelo

    2016-01-01

    Sensory reweighting is a characteristic of postural control functioning adopted to accommodate environmental changes. The use of mono or binocular cues induces visual reduction/increment of moving room influences on postural sway, suggesting a visual reweighting due to the quality of available sensory cues. Because in our previous study visual conditions were set before each trial, participants could adjust the weight of the different sensory systems in an anticipatory manner based upon the reduction in quality of the visual information. Nevertheless, in daily situations this adjustment is a dynamical process and occurs during ongoing movement. The purpose of this study was to examine the effect of visual transitions in the coupling between visual information and body sway in two different distances from the front wall of a moving room. Eleven young adults stood upright inside of a moving room in two distances (75 and 150 cm) wearing a liquid crystal lenses goggles, which allow individual lenses transition from opaque to transparent and vice-versa. Participants stood still during five minutes for each trial and the lenses status changed every one minute (no vision to binocular vision, no vision to monocular vision, binocular vision to monocular vision, and vice-versa). Results showed that farther distance and monocular vision reduced the effect of visual manipulation on postural sway. The effect of visual transition was condition dependent, with a stronger effect when transitions involved binocular vision than monocular vision. Based upon these results, we conclude that the increased distance from the front wall of the room reduced the effect of visual manipulation on postural sway and that sensory reweighting is stimulus quality dependent, with binocular vision producing a much stronger down/up-weighting than monocular vision. PMID:26939058

  3. Visualizing Dynamic Data with Maps.

    Mashima, Daisuke; Kobourov, Stephen G; Hu, Yifan

    2012-09-01

    Maps offer a familiar way to present geographic data (continents, countries), and additional information (topography, geology), can be displayed with the help of contours and heat-map overlays. In this paper, we consider visualizing large-scale dynamic relational data by taking advantage of the geographic map metaphor. We describe a map-based visualization system which uses animation to convey dynamics in large data sets, and which aims to preserve the viewer's mental map while also offering readable views at all times. Our system is fully functional and has been used to visualize user traffic on the Internet radio station last.fm, as well as TV-viewing patterns from an IPTV service. All map images in this paper are available in high-resolution at [1] as are several movies illustrating the dynamic visualization. PMID:22184261

  4. Data Visualization and Infographics

    Prepared by Mathematica Policy Research

    2014-01-01

    Data visualization translates complex ideas and concepts into a simple visual context. Patterns, trends, and relationships that might go undetected in text are conveyed at a glance in effective data visualization.

  5. Autoimmunity in visual loss.

    Petzold, Axel; Wong, Sui; Plant, Gordon T

    2016-01-01

    There are a number of autoimmune disorders which can affect visual function. There are a very large number of mechanisms in the visual pathway which could potentially be the targets of autoimmune attack. In practice it is the retina and the anterior visual pathway (optic nerve and chiasm) that are recognised as being affected in autoimmune disorders. Multiple Sclerosis is one of the commonest causes of visual loss in young adults because of the frequency of attacks of optic neuritis in that condition, however the basis of the inflammation in Multiple Sclerosis and the confirmation of autoimmunity is lacking. The immune process is known to be highly unusual in that it is not systemic and confined to the CNS compartment. Previously an enigmatic partner to Multiple Sclerosis, Neuromyelitis Optica is now established to be autoimmune and two antibodies - to Aquaporin4 and to Myelin Oligodendrocyte Glycoprotein - have been implicated in the pathogenesis. The term Chronic Relapsing Inflammatory Optic Neuropathy is applied to those cases of optic neuritis which require long term immunosuppression and hence are presumed to be autoimmune but where no autoimmune pathogenesis has been confirmed. Optic neuritis occurring post-infection and post vaccination and conditions such as Systemic Lupus Erythematosus and various vasculitides may cause direct autoimmune attack to visual structures or indirect damage through occlusive vasculopathy. Chronic granulomatous disorders such as Sarcoidosis affect vision commonly by a variety of mechanisms, whether and how these are placed in the autoimmune panoply is unknown. As far as the retina is concerned Cancer Associated Retinopathy and Melanoma Associated Retinopathy are well characterised clinically but a candidate autoantibody (recoverin) is only described in the former disorder. Other, usually monophasic, focal retinal inflammatory disorders (Idiopathic Big Blind Spot Syndrome, Acute Zonal Occult Outer Retinopathy and Acute Macular

  6. Learning Visualizations by Analogy: Promoting Visual Literacy through Visualization Morphing.

    Ruchikachorn, Puripant; Mueller, Klaus

    2015-09-01

    We propose the concept of teaching (and learning) unfamiliar visualizations by analogy, that is, demonstrating an unfamiliar visualization method by linking it to another more familiar one, where the in-betweens are designed to bridge the gap of these two visualizations and explain the difference in a gradual manner. As opposed to a textual description, our morphing explains an unfamiliar visualization through purely visual means. We demonstrate our idea by ways of four visualization pair examples: data table and parallel coordinates, scatterplot matrix and hyperbox, linear chart and spiral chart, and hierarchical pie chart and treemap. The analogy is commutative i.e. any member of the pair can be the unfamiliar visualization. A series of studies showed that this new paradigm can be an effective teaching tool. The participants could understand the unfamiliar visualization methods in all of the four pairs either fully or at least significantly better after they observed or interacted with the transitions from the familiar counterpart. The four examples suggest how helpful visualization pairings be identified and they will hopefully inspire other visualization morphings and associated transition strategies to be identified. PMID:26357285

  7. Visualization in Medieval Alchemy

    Barbara Obrist

    2003-10-01

    Full Text Available This paper explores major trends in visualization of medieval theories of natural and artificial transformation of substances in relation to their philosophical and theological bases. The function of pictorial forms is analyzed in terms of the prevailing conceptions of science and methods of transmitting knowledge. The documents under examination date from the thirteenth to the fifteenth century. In these, pictorial representations include lists and tables, geometrical figures, depictions of furnaces and apparatus, and figurative elements mainly from the vegetable and animal realms. An effort is made to trace the earliest evidence of these differing pictorial types.

  8. High-Resolution and Universal Visualization of Latent Fingerprints Based on Aptamer-Functionalized Core-Shell Nanoparticles with Embedded SERS Reporters.

    Zhao, Jingjing; Zhang, Kun; Li, Yixin; Ji, Ji; Liu, Baohong

    2016-06-15

    Although fingerprints have been widely used in forensic investigations, low resolution and poor universality are still the main obstacles for the development of fingerprint visualization. In this paper, a facile and universal imaging protocol for latent fingerprints (LFPs) was developed by combining sandwiched SERS probes with the highly sensitive and selective recognition of aptamers. The embedded SERS probes (Au/pNTP/SiO2) successfully avoid the environment interference, ascertaining the stability and reproducibility of Raman signals, and simultaneously improve the efficiency of the fingerprint identification. This approach is operationally simple without complicated pre- or post-treatments. Moreover, the fingerprint images display the high resolution in which third-level details can be clearly identified. This is a general approach and can be used to detect various types of fingerprints, including sebaceous, eccrine, fresh LFPs, and aged LFPs on different substrates (such as smooth, scratching, semiporous, and porous surfaces). PMID:27236904

  9. Effects of healthy aging on human primary visual cortex

    2012-01-01

    Aging often results in reduced visual acuity from changes in both the eye and neural circuits [1-4]. In normally aging subjects, primary visual cortex has been shown to have reduced responses to visual stimulation [5]. It is not known, however, to what extent aging affects visual field representations and population receptive sizes in human primary visual cortex. Here we use functional MRI (fMRI) and population receptive field (pRF) modeling [6] to measure angular and eccentric retinotopic re...

  10. Contrast sensitivity and visual disability in chronic simple glaucoma

    Ross, J E; Bron, A J; Clarke, D D

    1985-01-01

    A battery of vision tests was used to quantify visual defect in a group of 50 patients with chronic simple glaucoma. The vision tests were near and distance visual acuity, visual fields, and contrast sensitivity to static and temporally modulated sinusoidal grating patterns. Of these, static contrast sensitivity function appears to be the most sensitive method of measuring visual defect in glaucoma patients. The visual disability experienced by the glaucoma patients was quantified by means of...

  11. Universities’ visual image and Internet communication

    Okushova Gulnafist; Stakhovskaya Yuliya; Sharaev Pavel

    2016-01-01

    Universities of the 21st century are built on digital walls and on the Internet foundation. Their “real virtuality” of M. Castells is represented by information and communication flows that reflect various areas: education, research, culture, leisure, and others. The visual image of a university is the bridge that connects its physical and digital reality and identifies it within the information flow on the Internet. Visual image identification on the Internet and the function that the visual...

  12. Adaptive optics without altering visual perception

    Koenig,, I.; NW, Hart; HJ, Hofer

    2014-01-01

    Adaptive optics combined with visual psychophysics creates the potential to study the relationship between visual function and the retina at the cellular scale. This potential is hampered, however, by visual interference from the wavefront-sensing beacon used during correction. For example, we have previously shown that even a dim, visible beacon can alter stimulus perception (Hofer, H. J., Blaschke, J., Patolia, J., & Koenig, D. E. (2012). Fixation light hue bias revisited: Implications for ...

  13. Snowflake Visualization

    Bliven, L. F.; Kucera, P. A.; Rodriguez, P.

    2010-12-01

    NASA Snowflake Video Imagers (SVIs) enable snowflake visualization at diverse field sites. The natural variability of frozen precipitation is a complicating factor for remote sensing retrievals in high latitude regions. Particle classification is important for understanding snow/ice physics, remote sensing polarimetry, bulk radiative properties, surface emissivity, and ultimately, precipitation rates and accumulations. Yet intermittent storms, low temperatures, high winds, remote locations and complex terrain can impede us from observing falling snow in situ. SVI hardware and software have some special features. The standard camera and optics yield 8-bit gray-scale images with resolution of 0.05 x 0.1 mm, at 60 frames per second. Gray-scale images are highly desirable because they display contrast that aids particle classification. Black and white (1-bit) systems display no contrast, so there is less information to recognize particle types, which is particularly burdensome for aggregates. Data are analyzed at one-minute intervals using NASA's Precipitation Link Software that produces (a) Particle Catalogs and (b) Particle Size Distributions (PSDs). SVIs can operate nearly continuously for long periods (e.g., an entire winter season), so natural variability can be documented. Let’s summarize results from field studies this past winter and review some recent SVI enhancements. During the winter of 2009-2010, SVIs were deployed at two sites. One SVI supported weather observations during the 2010 Winter Olympics and Paralympics. It was located close to the summit (Roundhouse) of Whistler Mountain, near the town of Whistler, British Columbia, Canada. In addition, two SVIs were located at the King City Weather Radar Station (WKR) near Toronto, Ontario, Canada. Access was prohibited to the SVI on Whistler Mountain during the Olympics due to security concerns. So to meet the schedule for daily data products, we operated the SVI by remote control. We also upgraded the

  14. 中国可持续发展功能分区可视化系统研制%A Functional Zoning Visualization System for Sustainable Development in China

    安凯; 肖玉; 谢高地; 曹淑艳

    2012-01-01

    Functional zoning information for sustainable development with multidimensional spatio-temporal characters is the basis of regional planning and management. The adoption of geo-visualization technology to reveal underlying trends of sustainable development functional zoning along spatial and temporal gradients is also necessary. Based on visualization technology, component GIS and a spatial database engine we developed a system for sustainable development functional zoning visualization(SDFZV) that includes layers based on data source, meta-data, software components and functional modules. The data source layer integrated spatial data and socioeconomic data organized with the spatial database engine SuperMap SDX+. The meta-data layer was composed of a meta-data repository and meta-data engine. Meta-data were stored in the meta-data repository using uniform rules and standard formats. The meta-data engine encapsulated all meta-data repository operations and this ensured all components of the system had uniform access to meta-data with stable security. Software components were higher level abstractions than objects in object-oriented concepts. Software components were re-useable ingredients, which combined all kinds of objects. The SDFZV system made use of Microsoft .NET technology and SuperMap Objects as GIS platforms..NET wrapped COM components contained in SuperMap Objects into Windows Forms, which made it easily integrated with other components in .NET. The functional modules layer was composed of query, display and analysis, graph-visualization and geo-visualization modules. The query module had many search functions and spatial analysis abilities to find useful information spatially. The display and analysis module shows query results to users in table format and provides filtering, statistical analysis and indicator calculation functions. The graph-visualization module had seven types of charts and multiple settings to control the appearance of the graph

  15. The influence of anti-VEGF therapy on present day management of macular edema due to BRVO and CRVO: a longitudinal analysis on visual function, injection time interval and complications.

    Papadia, Marina; Misteli, Marie; Jeannin, Bruno; Herbort, Carl P

    2014-12-01

    The purpose of this study was to evaluate the impact of intravitreal bevacizumab injections on the management and outcome of patients affected by retinal vein occlusions, their effectiveness on morphological and functional parameters, the modalities of long-term management and the need for additional laser treatment due to ischemic retinal evolution. Patients diagnosed with branch retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO) had a comprehensive work-up including complete ophthalmic examination, fluorangiography (FA), optical coherence tomography (OCT), visual field testing (VFT), microperimetry (MP), and laser flare photometry (LFP). In case of BRVO, intraocular bevacizumab injection was performed if significant macular edema/visual deficit was still present 3 months after onset of occlusion and injections were started at presentation in case of CRVO. Post-injection follow-up examination including best corrected visual acuity (BCVA), intraocular pressure (IOP), LFP, OCT, MP, and VFT were performed monthly and recorded at the end of follow-up. Follow-up FA was performed between 12 and 18 months after diagnosis. Injections were repeated in case of recurrence of a significant central macular edema. Patients were subdivided into 2 groups according to number of injections: 1-4 injections or more than 4 injections. The proportion of resolved cases (no recurrence after a minimum follow-up of 12 months) was calculated and correlated with number of injections. In patients needing sustained injections, management modalities were recorded. The proportion of patients having needed laser photocoagulation treatment because of significant ischemic signs was recorded. Fifty-one patients were diagnosed with retinal vein occlusion between 2006 and 2012 at the Centre for Specialized Ophthalmic Care (COS) in Lausanne, Switzerland. Forty-four had enough data and were included in the study. Nine eyes were affected by CRVO and 35 were affected by BRVO. Mean BCVA

  16. Module structure of interphotoreceptor retinoid-binding protein (IRBP may provide bases for its complex role in the visual cycle – structure/function study of Xenopus IRBP

    Ghosh Debashis

    2007-08-01

    Full Text Available Abstract Background Interphotoreceptor retinoid-binding protein's (IRBP remarkable module structure may be critical to its role in mediating the transport of all-trans and 11-cis retinol, and 11-cis retinal between rods, cones, RPE and Müller cells during the visual cycle. We isolated cDNAs for Xenopus IRBP, and expressed and purified its individual modules, module combinations, and the full-length polypeptide. Binding of all-trans retinol, 11-cis retinal and 9-(9-anthroyloxy stearic acid were characterized by fluorescence spectroscopy monitoring ligand-fluorescence enhancement, quenching of endogenous protein fluorescence, and energy transfer. Finally, the X-ray crystal structure of module-2 was used to predict the location of the ligand-binding sites, and compare their structures among modules using homology modeling. Results The full-length Xenopus IRBP cDNA codes for a polypeptide of 1,197 amino acid residues beginning with a signal peptide followed by four homologous modules each ~300 amino acid residues in length. Modules 1 and 3 are more closely related to each other than either is to modules 2 and 4. Modules 1 and 4 are most similar to the N- and C-terminal modules of the two module IRBP of teleosts. Our data are consistent with the model that vertebrate IRBPs arose through two genetic duplication events, but that the middle two modules were lost during the evolution of the ray finned fish. The sequence of the expressed full-length IRBP was confirmed by liquid chromatography-tandem mass spectrometry. The recombinant full-length Xenopus IRBP bound all-trans retinol and 11-cis retinaldehyde at 3 to 4 sites with Kd's of 0.2 to 0.3 μM, and was active in protecting all-trans retinol from degradation. Module 2 showed selectivity for all-trans retinol over 11-cis retinaldehyde. The binding data are correlated to the results of docking of all-trans-retinol to the crystal structure of Xenopus module 2 suggesting two ligand-binding sites

  17. Nyctalopin Expression in Retinal Bipolar Cells Restores Visual Function in a Mouse Model of Complete X-Linked Congenital Stationary Night Blindness

    Gregg, Ronald G; Kamermans, Maarten; Klooster, Jan; Lukasiewicz, Peter D.; PEACHEY, NEAL S.; Kirstan A Vessey; McCall, Maureen A.

    2007-01-01

    Mutations in the NYX gene that encodes the protein nyctalopin cause congenital stationary night blindness type 1. In no b-wave (nob) mice, a mutation in Nyx results in a functional phenotype that includes the absence of the electroretinogram b-wave and abnormal spontaneous and light-evoked activity in retinal ganglion cells (RGCs). In contrast, there is no morphological abnormality in the retina at either the light or electron microscopic levels. These functional deficits suggest that nyctalo...

  18. Differential Functional Roles of Slow-Wave and Oscillatory-Alpha Activity in Visual Sensory Cortex during Anticipatory Visual–Spatial Attention

    Grent-'t-Jong, Tineke; Boehler, C. Nicolas; Kenemans, J Leon; Woldorff, Marty G.

    2011-01-01

    Markers of preparatory visual–spatial attention in sensory cortex have been described both as lateralized, slow-wave event-related potential (ERP) components and as lateralized changes in oscillatory-electroencephalography alpha power, but the roles of these markers and their functional relationship are still unclear. Here, 3 versions of a visual–spatial cueing paradigm, differing in perceptual task difficulty and/or response instructions, were used to investigate the functional relationships...

  19. Neocortical Rebound Depolarization Enhances Visual Perception.

    Funayama, Kenta; Minamisawa, Genki; Matsumoto, Nobuyoshi; Ban, Hiroshi; Chan, Allen W; Matsuki, Norio; Murphy, Timothy H; Ikegaya, Yuji

    2015-08-01

    Animals are constantly exposed to the time-varying visual world. Because visual perception is modulated by immediately prior visual experience, visual cortical neurons may register recent visual history into a specific form of offline activity and link it to later visual input. To examine how preceding visual inputs interact with upcoming information at the single neuron level, we designed a simple stimulation protocol in which a brief, orientated flashing stimulus was subsequently coupled to visual stimuli with identical or different features. Using in vivo whole-cell patch-clamp recording and functional two-photon calcium imaging from the primary visual cortex (V1) of awake mice, we discovered that a flash of sinusoidal grating per se induces an early, transient activation as well as a long-delayed reactivation in V1 neurons. This late response, which started hundreds of milliseconds after the flash and persisted for approximately 2 s, was also observed in human V1 electroencephalogram. When another drifting grating stimulus arrived during the late response, the V1 neurons exhibited a sublinear, but apparently increased response, especially to the same grating orientation. In behavioral tests of mice and humans, the flashing stimulation enhanced the detection power of the identically orientated visual stimulation only when the second stimulation was presented during the time window of the late response. Therefore, V1 late responses likely provide a neural basis for admixing temporally separated stimuli and extracting identical features in time-varying visual environments. PMID:26274866

  20. Impact of visual repetition rate on intrinsic properties of low frequency fluctuations in the visual network.

    Yi-Chia Li

    Full Text Available BACKGROUND: Visual processing network is one of the functional networks which have been reliably identified to consistently exist in human resting brains. In our work, we focused on this network and investigated the intrinsic properties of low frequency (0.01-0.08 Hz fluctuations (LFFs during changes of visual stimuli. There were two main questions to be discussed in this study: intrinsic properties of LFFs regarding (1 interactions between visual stimuli and resting-state; (2 impact of repetition rate of visual stimuli. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed scanning sessions that contained rest and visual stimuli in various repetition rates with a novel method. The method included three numerical approaches involving ICA (Independent Component Analyses, fALFF (fractional Amplitude of Low Frequency Fluctuation, and Coherence, to respectively investigate the modulations of visual network pattern, low frequency fluctuation power, and interregional functional connectivity during changes of visual stimuli. We discovered when resting-state was replaced by visual stimuli, more areas were involved in visual processing, and both stronger low frequency fluctuations and higher interregional functional connectivity occurred in visual network. With changes of visual repetition rate, the number of areas which were involved in visual processing, low frequency fluctuation power, and interregional functional connectivity in this network were also modulated. CONCLUSIONS/SIGNIFICANCE: To combine the results of prior literatures and our discoveries, intrinsic properties of LFFs in visual network are altered not only by modulations of endogenous factors (eye-open or eye-closed condition; alcohol administration and disordered behaviors (early blind, but also exogenous sensory stimuli (visual stimuli with various repetition rates. It demonstrates that the intrinsic properties of LFFs are valuable to represent physiological states of human brains.

  1. Perfil morfofuncional de pacientes com retinopatia diabética sem baixa acuidade visual severa em hospital público de referência em diabetes no Brasil Morpho-functional profile of patients with diabetic retinopathy without severe loss of visual acuity in a public hospital of reference in diabetes in Brazil

    Alípio de Sousa Neto

    2010-02-01

    que o grupo da endocrinologia.OBJECTIVE: To demonstrate the morpho-functional profile of the evaluation of patients with diabetic retinopathy without severe loss of visual acuity in a public hospital of reference in endocrinology, determining in this sample, the relation between the time of diabetes, age and visual acuity with the retinal thickness measured by the optical Coherence tomography (OCT and fundus picture (FP. METHODS: Prospective, linear study was carried through, in transversal cut of 61 consecutive patients with diabetic retinopathy registered in the HRT, and refered from the services of ophthalmology and endocrinology. Patients had been submitted to a complete ophthalmic evaluation including clinical history, visual acuity with correction and pin hole. The patients who had presented diabetic retinopathy, with transparent media, without previous surgery, nor previous Laser photocoagulation and with visual acuity better than 20/100 at Snelen scale, had been included in the study. After the elimination of the patients who had not obeyed the inclusion/exclusion criteria 109 eyes of 55 patients then had been submitted the OCT and FP for evaluation of the presence or absence of edema by the FP and of the quantitative evaluation (measured of the retinal thickness of the 9 regions of the pelo Early Tratment Diabetic Retinophaty Study (ETDRS, and of the qualitative evaluation (presence or absence of retinal edema for the central slit, number 1. RESULTS: The average time of diabetes was of 12 years, varying of 23 to 86 years old. 51% were female, and 49% male. The OCT demonstrated discrete reduction of the retinal thickness with elapsing of the age. The patients of the ophthalmology had greaters values of retinal thickness of what of the group of the endocrinology. The evaluation of the visual acuity improved with pin hole in 47% (51/109. The endocrinology group were 45% (23/50 of the eyes and the ophthalmology group were 55% (28/59. Only 22% (24/109 of the eyes

  2. The measure for problematic case with middle meningeal artery origin ophthalmic artery in front-temporal craniotomy and a part of DSA. Preservation of visual function

    Because of the recent development of high-performance 3-dimensional computed tomography (3D-CTA), magnetic resonance angiography (MRA) and the consideration of the risk of digital subtraction angiography (DSA), DSA is not always necessary in performing surgery for cerebral aneurysms. However, DSA was necessary in patients in whom the ophthalmic artery from the internal carotid artery (IC) was not visualized on 3D-CTA or MRA, in order to predict the risk of blindness after front-temporal craniotomy. In this study, we investigated the preoperative evaluation and the surgical procedure for 330 cases of front-temporal craniotomy for surgery of aneurysm over the past 4.5 years. There were 5 cases without ophthalmic artery from IC in DSA or 3D-CTA, 4 cases with an anomalous ophthalmic artery arising from the middle meningeal artery and 1 case with an anomalous ophthalmic artery arising from unknown origin. Microsurgical procedure is needed to preserve the middle meningeal artery in front-temporal craniotomy in these cases with an anomalous ophthalmic artery arising from the middle meningeal artery, because this anomaly places the ophthalmic artery at risk during procedures in which the dura is elevated from the greater and lesser wings of the sphenoid or when the sphenoid ridge is removed in front-temporal craniotomy. Front-temporal craniotomy is difficult in cases with an anomalous ophthalmic artery arising from an unknown origin. (author)

  3. VCAT: Visual Crosswalk Analysis Tool

    Cleland, Timothy J. [Los Alamos National Laboratory; Forslund, David W. [Los Alamos National Laboratory; Cleland, Catherine A. [Los Alamos National Laboratory

    2012-08-31

    VCAT is a knowledge modeling and analysis tool. It was synthesized from ideas in functional analysis, business process modeling, and complex network science. VCAT discovers synergies by analyzing natural language descriptions. Specifically, it creates visual analytic perspectives that capture intended organization structures, then overlays the serendipitous relationships that point to potential synergies within an organization or across multiple organizations.

  4. The DynAlloy Visualizer

    Bendersky, Pablo; Galeotti, Juan Pablo; Garbervetsky, Diego

    2014-01-01

    We present an extension to the DynAlloy tool to navigate DynAlloy counterexamples: the DynAlloy Visualizer. The user interface mimics the functionality of a programming language debugger. Without this tool, a DynAlloy user is forced to deal with the internals of the Alloy intermediate representation in order to debug a flaw in her model.

  5. Visualizing quantum mechanics in phase space

    Bauke, Heiko; Itzhak, Noya Ruth

    2011-01-01

    We examine the visualization of quantum mechanics in phase space by means of the Wigner function and the Wigner function flow as a complementary approach to illustrating quantum mechanics in configuration space by wave functions. The Wigner function formalism resembles the mathematical language of classical mechanics of non-interacting particles. Thus, it allows a more direct comparison between classical and quantum dynamical features.

  6. Learning bimodal structure in audio-visual data

    Monaci, Gianluca; Vandergheynst, Pierre; Sommer, Friederich T.

    2009-01-01

    A novel model is presented to learn bimodally informative structures from audio-visual signals. The signal is represented as a sparse sum of audio- visual kernels. Each kernel is a bimodal function consisting of synchronous snippets of an audio waveform and a spatio-temporal visual basis function. To represent an audio-visual signal, the kernels can be positioned independently and arbitrarily in space and time. The proposed algorithm uses unsupervised learning to form dicti...

  7. VISUAL LANDSCAPE PERCEPTION

    ASLAN, Fürüzan; Aslan, Edanur; Atik, Atilla

    2015-01-01

    Landscape, the way that people perceive, is described as areas the characteristics of which are made up as a result of the interaction and activity of natural and/or human factors. The composition which is formed as a result of this interaction of natural and cultural components sets forth the visual landscape conception.In the scope of study landscape, perception, visual landscape concepts, visual design factors and visual design principles in support of related descriptions and the visuals ...

  8. Visual thinking & digital imagery

    Blevis, Eli; Churchill, Elizabeth; Odom, William; Pierre, James; Roedl, David; Wakkary, Ron

    2012-01-01

    This workshop focuses on exploring the centrality of visual literacy and visual thinking to HCI. Drawing on emerging critical perspectives, the workshop will address visual literacy and visual thinking from an interdisciplinary and transdisciplinary design-orientation [2, 8], foregrounding the notion that imagery is a primary form of visual thinking. Imagery—which subsumes digital imagery—goes well beyond sketching and beyond storyboards, screenshots and wireframes. We will address how a broa...

  9. A Visual Culture: Approach to Art Education

    Knight, Wanda B.; Keifer-Boyd; Amburgy, Patricia M.

    2007-01-01

    People are immersed in visual culture and, therefore, are usually not aware of how power and privilege are enacted and how they operate in works of art from past and present times. Two premises infuse individuals' thinking on visual culture. First, that an activity-based approach to its study seeks to recognize how power and privilege function in…

  10. Learning QlikView data visualization

    Pover, Karl

    2013-01-01

    A practical and fast-paced guide that gives you all the information you need to start developing charts from your data.Learning QlikView Data Visualization is for anybody interested in performing powerful data analysis and crafting insightful data visualization, independent of any previous knowledge of QlikView. Experience with spreadsheet software will help you understand QlikView functions.

  11. Visual thinking in organizational analysis

    Grantham, Charles E.

    1991-06-01

    The ability to visualize the relationship among elements of large complex databases is a trend which is yielding new insights into several fields. The author demonstrates the use of 'visual thinking' as an analytical tool to the analysis of formal, complex organizations. Recent developments in organizational design and office automation are making the visual analysis of workflows possible. An analytical mental model of organizational functioning can be built upon a depiction of information flows among work group members. The dynamics of organizational functioning can be described in terms of six essential processes. Furthermore, each of these sub-systems develop within a staged cycle referred to as an enneagram model. Together these mental models present a visual metaphor of healthy function in large formal organizations; both in static and dynamic terms. These models can be used to depict the 'state' of an organization at points in time by linking each process to quantitative data taken from the monitoring of the flow of information in computer networks.

  12. Universal visualization platform

    Gee, Alexander G.; Li, Hongli; Yu, Min; Smrtic, Mary Beth; Cvek, Urska; Goodell, Howie; Gupta, Vivek; Lawrence, Christine; Zhou, Jainping; Chiang, Chih-Hung; Grinstein, Georges G.

    2005-03-01

    Although there are a number of visualization systems to choose from when analyzing data, only a few of these allow for the integration of other visualization and analysis techniques. There are even fewer visualization toolkits and frameworks from which one can develop ones own visualization applications. Even within the research community, scientists either use what they can from the available tools or start from scratch to define a program in which they are able to develop new or modified visualization techniques and analysis algorithms. Presented here is a new general-purpose platform for constructing numerous visualization and analysis applications. The focus of this system is the design and experimentation of new techniques, and where the sharing of and integration with other tools becomes second nature. Moreover, this platform supports multiple large data sets, and the recording and visualizing of user sessions. Here we introduce the Universal Visualization Platform (UVP) as a modern data visualization and analysis system.

  13. Assessment of visual function based on IOL-Master comparing with traditional ultrasonic biometry for intraocular lens calculation in high myopia patients

    Lu Zhang

    2013-10-01

    Full Text Available AIM: To evaluate the clinical feasibility of using a new optical coherence interferometry(IOL-Master, comparing with traditional ultrasonic biometry and manual keratometry in the accuracy and characteristics for intraocular lens calculation of high myopia.METHODS: The measurement of axial length was performed in 60 eyes(30 eyes for each groupwith senile cataract of high myopia(≥-6.00Dusing IOL-Master and ultrasonic biometry. The measurement of corneal power(Kwas also performed in the patient using IOL-Master and manual keratometry preoperatively. Phacoemulsification and foldable lens implantation were done on the patients. IOL power calculation was carried out according to the SRK/T formula on the basis of the group-related data. Best corrected visual acuity, refraction, contrast sensitivity and wave front aberration root mean square(RMSwere re-tested after 3 months postoperatively.RESULTS: Significant difference between the two methods in axial length measurement which was 29.81±1.53mm by ultrasound and 29.63±1.81mm by IOL-Master(P=0.001. And in corneal power measurement which was 43.22±1.67K by manual keratometry and 44.27±1.39K by IOL-Master(P=0.006. There was a significant difference between the two groups(P=0.001. 63.0% vs 31.2% had a mean absolute refractive error(MAREwithin ±0.50 diopter for the IOL-Master and A-scan groups, respectively(χ2=3.1, Pth order aberration, 4th order spherical aberration and total high order aberration in the IOL-Master group were lower than those in the A-scan group at 6mm pupil diameter 3 months later. CONCLUSION: IOL-Master is a non-contact, accurate, safe and reliable tool for calculating IOL power and it is more accurate on the design of the IOL in the cataract surgery on the high myopia patients.

  14. The nob2 mouse, a null mutation in Cacna1f: Anatomical and functional abnormalities in the outer retina and their consequences on ganglion cell visual responses

    Chang, Bo; Heckenlively, John R.; BAYLEY, PHILIPPA R.; Brecha, Nicholas C.; Davisson, Muriel T.; HAWES, NORM L.; Hirano, Arlene A.; HURD, RONALD E.; Ikeda, Akihiro; Johnson, Britt A; McCall, Maureen A.; Morgans, Catherine W.; NUSINOWITZ, STEVE; PEACHEY, NEAL S.; Rice, Dennis S.

    2006-01-01

    Glutamate release from photoreceptor terminals is controlled by voltage-dependent calcium channels (VDCCs). In humans, mutations in the Cacna1f gene, encoding the α1F subunit of VDCCs, underlie the incomplete form of X-linked congenital stationary night blindness (CSNB2). These mutations impair synaptic transmission from rod and cone photoreceptors to bipolar cells. Here, we report anatomical and functional characterizations of the retina in the nob2 (no b-wave 2) mouse, a naturally occurring...

  15. Direct visualization of changes of lymphatic function and drainage pathways in lymph node metastasis of B16F10 melanoma using near-infrared fluorescence imaging

    Kwon, Sunkuk; Agollah, Germaine D.; Wu, Grace; Chan, Wenyaw; Sevick-Muraca, Eva M

    2013-01-01

    The lymphatic system provides an initial route for cancer cell dissemination in many cancers including melanoma. However, it is largely unknown how the lymphatic system changes during tumor progression due in part to the lack of imaging techniques currently available. In this study, we non-invasively imaged changes of lymphatic function and drainage patterns using near-infrared fluorescence (NIRF) imaging. Dynamic NIRF imaging following intradermal injection of indocyanine green (ICG) was con...

  16. A ventral visual stream reading center independent of visual experience.

    Reich, Lior; Szwed, Marcin; Cohen, Laurent; Amedi, Amir

    2011-03-01

    The visual word form area (VWFA) is a ventral stream visual area that develops expertise for visual reading. It is activated across writing systems and scripts and encodes letter strings irrespective of case, font, or location in the visual field with striking anatomical reproducibility across individuals. In the blind, comparable reading expertise can be achieved using Braille. This study investigated which area plays the role of the VWFA in the blind. One would expect this area to be at either parietal or bilateral occipital cortex, reflecting the tactile nature of the task and crossmodal plasticity, respectively. However, according to the metamodal theory, which suggests that brain areas are responsive to a specific representation or computation regardless of their input sensory modality, we predicted recruitment of the left-hemispheric VWFA, identically to the sighted. Using functional magnetic resonance imaging, we show that activation during Braille reading in blind individuals peaks in the VWFA, with striking anatomical consistency within and between blind and sighted. Furthermore, the VWFA is reading selective when contrasted to high-level language and low-level sensory controls. Thus, we propose that the VWFA is a metamodal reading area that develops specialization for reading regardless of visual experience. PMID:21333539

  17. Developing a Korean standard brain atlas on the basis of statistical and probabilistic approach and visualization tool for functional image analysis

    The probabilistic anatomical maps are used to localize the functional neuro-images and morphological variability. The quantitative indicator is very important to inquire the anatomical position of an activated region because functional image data has the low-resolution nature and no inherent anatomical information. Although previously developed MNI probabilistic anatomical map was enough to localize the data, it was not suitable for the Korean brains because of the morphological difference between Occidental and Oriental. In this study, we develop a probabilistic anatomical map for Korean normal brain. Normal 75 brains of T1-weighted spoiled gradient echo magnetic resonance images were acquired on a 1.5-T GESIGNA scanner. Then, a standard brain is selected in the group through a clinician searches a brain of the average property in the Talairach coordinate system. With the standard brain, an anatomist delineates 89 regions of interest (ROI) parcellating cortical and subcortical areas. The parcellated ROIs of the standard are warped and overlapped into each brain by maximizing intensity similarity. And every brain is automatically labeled with the registered ROIs. Each of the same-labeled region is linearly normalize to the standard brain, and the occurrence of each region is counted. Finally, 89 probabilistic ROI volumes are generated. This paper presents a probabilistic anatomical map for localizing the functional and structural analysis of Korean normal brain. In the future, we'll develop the group specific probabilistic anatomical maps of OCD and schizophrenia disease

  18. Developing a Korean standard brain atlas on the basis of statistical and probabilistic approach and visualization tool for functional image analysis

    Koo, B. B.; Lee, J. M.; Kim, J. S.; Kim, I. Y.; Kim, S. I. [Hanyang University, Seoul (Korea, Republic of); Lee, J. S.; Lee, D. S.; Kwon, J. S. [Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, J. J. [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2003-06-01

    The probabilistic anatomical maps are used to localize the functional neuro-images and morphological variability. The quantitative indicator is very important to inquire the anatomical position of an activated region because functional image data has the low-resolution nature and no inherent anatomical information. Although previously developed MNI probabilistic anatomical map was enough to localize the data, it was not suitable for the Korean brains because of the morphological difference between Occidental and Oriental. In this study, we develop a probabilistic anatomical map for Korean normal brain. Normal 75 brains of T1-weighted spoiled gradient echo magnetic resonance images were acquired on a 1.5-T GESIGNA scanner. Then, a standard brain is selected in the group through a clinician searches a brain of the average property in the Talairach coordinate system. With the standard brain, an anatomist delineates 89 regions of interest (ROI) parcellating cortical and subcortical areas. The parcellated ROIs of the standard are warped and overlapped into each brain by maximizing intensity similarity. And every brain is automatically labeled with the registered ROIs. Each of the same-labeled region is linearly normalize to the standard brain, and the occurrence of each region is counted. Finally, 89 probabilistic ROI volumes are generated. This paper presents a probabilistic anatomical map for localizing the functional and structural analysis of Korean normal brain. In the future, we'll develop the group specific probabilistic anatomical maps of OCD and schizophrenia disease.

  19. Visualization in Scanning

    Scanning is essentially a method of making the unknown known, and for the vast majority of scanning work this means making the invisible visible. Visualization is developed as a process involving a model of eye and brain function, display performance and counter performance combined with the spatial frequency components in the object scanned. The performance of a scanner or gamma camera depends in part on its display system and experiments have been performed to determine the fractional change in count-rate which can be perceived by the eye from colour, photoscan and cathode-ray tube displays, for both circular and line sources of radioactivity. For circular sources, colour and photoscan displays are capable of making 10% increases in count-rate perceptible in backgrounds ranging from 5 to 100 counts/s for sources of 1 to 4 cm diameter, whilst cathode-ray tube and black-mark displays show only 20% at best. The results for line sources are also given. In testing for the statistical significance of count-rate differences on a scan, the counts are usually compared for equal areas. On this basis the cathode-ray tube display is only able to show five standard deviations of difference whereas colour and photoscan displays show from 2.5 to 3 standard deviations, levels not usually accepted statistically as significant. It is suggested that if the eye examines the areas surrounding the area of interest then the significance of a count-rate difference may be established more accurately and in general will be increased, thereby accounting for the visualization of apparently 'insignificant' regions. This theory is used to predict the areas of count density which should be visually perceived in the presence of noise, and extended to consider practical display conditions, which have been described in this paper. The performance of a scanner can be considered in terms of its modulation transfer function (derived from a line spread function). Fourier analysis has been performed

  20. Interaction for visualization

    Tominski, Christian

    2015-01-01

    Visualization has become a valuable means for data exploration and analysis. Interactive visualization combines expressive graphical representations and effective user interaction. Although interaction is an important component of visualization approaches, much of the visualization literature tends to pay more attention to the graphical representation than to interaction.The goal of this work is to strengthen the interaction side of visualization. Based on a brief review of general aspects of interaction, we develop an interaction-oriented view on visualization. This view comprises five key as

  1. Visual attention capacity after right hemisphere lesions

    Habekost, Thomas; Rostrup, Egill

    2007-01-01

    whole report experiment for estimation of these two parameters in 22 patients with right side stroke. Psychophysical performance was analyzed using Bundesen's [Bundesen, C. (1990). A theory of visual attention. Psychological Review, 97, 523-547] Theory of Visual Attention (TVA) and compared......Recently there has been a growing interest in visual short-term memory (VSTM) including the neural basis of the function. Processing speed, another main aspect of visual attention capacity, has received less investigation. For both cognitive functions human lesion studies are sparse. We used a...... both VSTM capacity and ipsilesional processing speed. The study also showed that lesions in a large region of the right hemisphere, including the putamen, insula, and inferior frontal cortex, do not lead to general deficits in the capacity of visual attention. Udgivelsesdato: 2007-Apr-8...

  2. Neurophysiology of visual aura in migraine

    Visual processing in migraine has been targeted because the visual symptoms that are commonly associated with attack, either in the form of aura or other more subtle symptoms, indicate that the visual pathways are involved in migrainous pathophysiology. The visual aura of the migraine attack has been explained by the cortical spreading depression (CSD) of Leao, neuroelectric event beginning in the occipital cortex and propagating into contiguous brain region. Clinical observations suggest that hyperexcitability occurs not only during the attack, typically in the form of photophobia, but also between attacks. Numerous human neuroimaging, neurophysiological and psychophysical studies have identified differences in cortical visual processing in migraine. The possibility of imaging the typical visual aura with BOLD functional MRI has revealed multiple neurovascular events in the occipital cortex within a single attack that closely resemble CSD. As transient synchronized neuronal excitation precedes CSD, changes in cortical excitability underlie the migraine attack. Independent evidence for altered neuronal excitability in migraineurs between attacks emerges from visual evoked potentials (VEPs) and transcranial magnetic stimulation (TMS), recordings of cortical potentials and psychophysics. Recently, both TMS and psychophysical studies measuring visual performance in migraineurs have used measures which presumably measure primary visual (V1) and visual association cortex. Our VEP and blink reflex study showed that migraine patients exhibiting allodynia might show central sensitization of braistem trigeminal neuron and had contrast modulation dysfunction during the cortical visual processing of V1 and visual association cortex in-between attacks. In pathophysiology of migraine, these neurophysiological and psychophysical studies indicate that abnormal visual and trigeminal hyperexcitability might persist between migraine attacks. The influence of migraine on cortical

  3. Enhancing visual acuity.

    Stalmans, Peter

    2014-01-01

    The Enhancing Visual Acuity (EVA) System (Dutch Ophthalmic Research Centre International B.V.) features a unique fluid control system - VacuFlow Valve Timing Intelligence (VTi®) - and represents the next-generation evolution of pump machines. VacuFlow VTi® overcomes the limitations of existing Venturi and peristaltic pumps and provides the potential to enable safer, faster, and more precise techniques. Alongside many other innovative and functional features, such as a light-emitting diode light source, integrated laser, high cutting speed with twin duty cycle cutting, automated infusion compensation, wireless foot pedal, phaco module with thresholding, and viscous fluid module, EVA could make a major contribution to advancing ophthalmology. PMID:25196748

  4. Visual acuity evaluated by pattern-reversal visual-evoked potential is affected by check size/visual angle

    Xiping Chen; Qianqian Li; Xiaoqin Liu; Li Yang; Wentao Xia; Luyang Tao

    2012-01-01

    Objective To systemically explore the range of visual angles that affect visual acuity,and to establish the relationship between the P 1 component (peak latency ~100 ms) of the pattern-reversal visual-evoked potential (PRVEP) and the visual acuity at particular visual angles.Methods Two hundred and ten volunteers were divided into seven groups,according to visual acuity as assessed by the standard logarithmic visual acuity chart (SLD-II).For each group,the PRVEP components were elicited in response to visual angle presentations at 8°,4°,2°,1 °/60′,30′,15′,and 7.5′,in the whiteblack chess-board reversal mode with a contrast level of 100% at a frequency of 2 Hz.Visual stimuli were presented monocularly,and 200 presentations were averaged for each block of trials.The early and stable component P1 was recorded at the mid-line of the occipital region (Oz) and analyzed with SPSS 13.00.Results (1) Oz had the maximum P1 amplitude;there was no significant difference between genders or for interocular comparison in normal controls and subjects with optic myopia.(2) The P1 latency decreased slowly below 30′,then increased rapidly.The P1 amplitude initially increased with check size,and was maximal at ~1° and ~30′.(3) The P1 latency in the group with visual acuity ≤0.2 was significantly different at 8°,15′ and 7.5′,while the amplitude differed at all visual angles,compared with the group with normal vision.Diferences in P1 for the groups with 0.5 and 0.6 acuity were only present at visual angles <1°.(4) Regression analysis showed that the P 1 latency and amplitude were associated with visual acuity over the full range of visual angles.There was a moderate correlation at visual angles <30′.Regression equations were calculated for the P1 components and visual acuity,based on visual angle.Conclusion (1) Visual angle should be taken into consideration when exploring the function of the visual pathway,especially visual acuity.A visual angle

  5. Lessons Learned from Designing Visualization Dashboards.

    Froese, Maria-Elena; Tory, Melanie

    2016-01-01

    A variety of visualization guidelines, principles, and techniques are available to help create a visualization-based dashboard, but few publications discuss the experience of designing dashboards in the real world. This article discuss the lessons learned from designing applications for small start-up companies and institutions. From their experience as visualization practitioners, the authors confirm the need for tailored and customizable approaches, emphasize the need for a quicker way to create functional prototypes, point out frequent misconceptions on the scope of a functional prototype, discuss how performance can affect prototyping, and discuss the resistance of industrial partners to involve their customers in requirements gathering. PMID:26960030

  6. Conceptual size representation in ventral visual cortex.

    Gabay, Shai; Kalanthroff, Eyal; Henik, Avishai; Gronau, Nurit

    2016-01-29

    Recent findings suggest that visual objects may be mapped along the ventral occipitotemporal cortex according to their real-world size (Konkle and Oliva, 2012). It has been argued that such mapping does not reflect an abstract, conceptual size representation, but rather the visual or functional properties associated with small versus big real-world objects. To determine whether a more abstract conceptual size representation may affect visual cortical activation we used meaningless geometrical shapes, devoid of semantic or functional associations, which were associated with specific size representations by virtue of extensive training. Following training, participants underwent functional magnetic resonance imaging (fMRI) scanning while performing a conceptual size comparison task on the geometrical shapes. In addition, a size comparison task was conducted for numeral digits denoting small and big numbers. A region-of-interest analysis revealed larger blood oxygenation level dependent (BOLD) responses for conceptually 'big' than for conceptually 'small' shapes, as well as for big versus small numbers, within medial (parahippocampal place area, PPA) and lateral (occipital place area, OPA) place-selective regions. Processing of the 'big' visual shapes further elicited enhanced activation in early visual cortex, possibly reflecting top-down projections from PPA. By using arbitrary shapes and numbers we minimized visual, categorical, or functional influences on fMRI measurement, providing evidence for a possible neural mechanism underlying the representation of abstract conceptual size within the ventral visual stream. PMID:26731198

  7. The macular threshold protocol of the Humphrey visual field analyzer: a superior functional outcome of intravitreal bevacizumab for the treatment of neovascular age-related macular degeneration Desfecho funcional superior da eficácia do tratamento com bevacizumab intravítreo em degeneração macular relacionada à idade, por meio do protocolo de limiar macular do campímetro de Humphrey

    Fabio Lavinsky; Micheal John Tolentino; Jaco Lavinsky

    2010-01-01

    PURPOSE: To evaluate the decibel loss on the Macular threshold protocol of the Humphrey visual field as a reliable functional outcome of the intravitreal bevacizumab treatment. METHODS: Thirteen patients were evaluated at baseline and on the week 6 for best corrected visual acuity, optical coherence tomography central macular thickness and decibel loss on Macular threshold protocol of the Humphrey visual field after 1.25 mg intravitreal injection of bevacizumab. The outcomes were analyzed sep...

  8. Visualization of Social Networks

    Boertjes, E.M.; Kotterink, B.; Jager, E.J.

    2011-01-01

    Current visualizations of social networks are mostly some form of node-link diagram. Depending on the type of social network, this can be some treevisualization with a strict hierarchical structure or a more generic network visualization.

  9. Visualizing Knowledge Domains.

    Borner, Katy; Chen, Chaomei; Boyack, Kevin W.

    2003-01-01

    Reviews visualization techniques for scientific disciplines and information retrieval and classification. Highlights include historical background of scientometrics, bibliometrics, and citation analysis; map generation; process flow of visualizing knowledge domains; measures and similarity calculations; vector space model; factor analysis;…

  10. Constructing visual representations

    Huron, Samuel; Jansen, Yvonne; Carpendale, Sheelagh

    2014-01-01

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

  11. Topological Methods for Visualization

    Berres, Anne Sabine [Los Alamos National Lab. (LANL), Los Alamos, NM (United Stat

    2016-04-07

    This slide presentation describes basic topological concepts, including topological spaces, homeomorphisms, homotopy, betti numbers. Scalar field topology explores finding topological features and scalar field visualization, and vector field topology explores finding topological features and vector field visualization.

  12. Visual field constriction as a cause of blindness or visual impairment.

    Murdoch, I. E.; Jones, B R; Cousens, S; Liman, I; O. E. Babalola; Dauda, J.; Abiose, A

    1997-01-01

    Reported are the results of a study of onchocerciasis in communities mesoendemic for savanna onchocerciasis in Kaduna State, northern Nigeria. The study involved 6831 individuals aged > or = 5 years who underwent an extensive screening examination for visual function including Friedmann field analysis. A total of 185 (2.7%) were bilaterally blind by acuity and an additional 28 (0.4%) were blind by visual field constriction. Also 118 (1.7%) individuals were visually impaired by acuity criteria...

  13. Visual similarity is stronger than semantic similarity in guiding visual search for numbers

    Godwin, H.J.; Hout, M.C.; Menneer, T.

    2014-01-01

    Using a visual search task, we explored how behavior is influenced by both visual and semantic information. We recorded participants’ eye movements as they searched for a single target number in a search array of single-digit numbers (0–9). We examined the probability of fixating the various distractors as a function of two key dimensions: the visual similarity between the target and each distractor, and the semantic similarity (i.e., the numerical distance) between the target and each distra...

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

    Delfour, F; Marten, K

    2006-01-10

    Analyzing cerebral asymmetries in various species helps in understanding brain organization. The left and right sides of the brain (lateralization) are involved in different cognitive and sensory functions. This study focuses on dolphin visual lateralization as expressed by spontaneous eye preference when performing a complex cognitive task; we examine lateralization when processing different visual stimuli displayed on an underwater touch-screen (two-dimensional figures, three-dimensional figures and dolphin/human video sequences). Three female bottlenose dolphins (Tursiops truncatus) were submitted to a 2-, 3- or 4-, choice visual/auditory discrimination problem, without any food reward: the subjects had to correctly match visual and acoustic stimuli together. In order to visualize and to touch the underwater target, the dolphins had to come close to the touch-screen and to position themselves using monocular vision (left or right eye) and/or binocular naso-ventral vision. The results showed an ability to associate simple visual forms and auditory information using an underwater touch-screen. Moreover, the subjects showed a spontaneous tendency to use monocular vision. Contrary to previous findings, our results did not clearly demonstrate right eye preference in spontaneous choice. However, the individuals' scores of correct answers were correlated with right eye vision, demonstrating the advantage of this visual field in visual information processing and suggesting a left hemispheric dominance. We also demonstrated that the nature of the presented visual stimulus does not seem to have any influence on the animals' monocular vision choice. PMID:16246503

  15. Everyday-like memory for objects in ageing and Alzheimer's disease assessed in a visually complex environment: The role of executive functioning and episodic memory.

    Sauzéon, Hélène; N'Kaoua, Bernard; Pala, Prashant Arvind; Taillade, Mathieu; Auriacombe, Sophie; Guitton, Pascal

    2016-03-01

    To investigate everyday memory, more and more studies rely on virtual-reality applications to bridge the gap between in situ approaches and laboratory settings. In this vein, the present study was designed to assess everyday-like memory from the virtual reality-based Human Object Memory for Everyday Scenes (HOMES) test (Sauzéon et al., , Exp. Psychol., 59, 99) in ageing and in Alzheimer's disease (AD). Two aims motivated this study: the first was to assess multiple processes of episodic memory (EM) functioning embedded within contexts closely related to real life in ageing and AD using the multi-trial free-recall paradigm, and the second aim was to evaluate the mediating effects of executive functioning (EF), EM, and subjective memory complaints (SMCs) on age differences in the HOMES measures and in AD. To this end, the HOMES test and neurocognitive tests of EF and EM were administered to 23 younger adults, 23 older adults, and 16 patients with AD. The results were: firstly, compared to young adults, elderly adults presented only free-recall decline that almost disappeared in recognition condition whereas AD patients exhibited a poor clustering, learning, and recognition performance, and also a high amount of false recognition; secondly, age differences as well as AD related deficits on the HOMES test were mediated by both memory and EF measure while those observed on false memory indices were only mediated by EM measure; thirdly, the HOMES indices are related to SMCs even when episodic or EF measures are controlled. Overall, the results supported the fact that the VR-based memory test is an appropriate device to capture age-related differences as well as the AD effect with respect to both in situ and laboratory settings. PMID:25307794

  16. Visual experience and blindsight

    Overgaard, Morten

    2011-01-01

    Blindsight is classically defined as residual visual capacity, e.g., to detect and identify visual stimuli, in the total absence of perceptual awareness following lesions to V1. However, whereas most experiments have investigated what blindsight patients can and cannot do, the literature contains...... several, often contradictory, remarks about remaining visual experience. This review examines closer these remarks as well as experiments that directly approach the nature of possibly spared visual experiences in blindsight....

  17. Visual Data Mining Techniques

    Keim, Daniel A.; Ward, Matthew O.

    2002-01-01

    Never before in history has data been generated at such high volumes as it is today. Exploring and analyzing the vast volumes of data has become increasingly difficult. Information visualization and visual data mining can help to deal with the flood of information. The advantage of visual data exploration is that the user is directly involved in the data mining process. There are a large number of information visualization techniques that have been developed over the last two decades to suppo...

  18. Visual explorer facilitator's guide

    Palus, Charles J

    2010-01-01

    Grounded in research and practice, the Visual Explorer™ Facilitator's Guide provides a method for supporting collaborative, creative conversations about complex issues through the power of images. The guide is available as a component in the Visual Explorer Facilitator's Letter-sized Set, Visual Explorer Facilitator's Post card-sized Set, Visual Explorer Playing Card-sized Set, and is also available as a stand-alone title for purchase to assist multiple tool users in an organization.

  19. Tools for software visualization

    Stojanova, Aleksandra; Stojkovic, Natasa; Bikov, Dusan

    2015-01-01

    Software visualization is a kind of computer art, and in the same time is a science for generating visual representations of different software aspects and of software development process. There are many tools that allow software visualization but we are focusing on some of them. In this paper will be examined in details just four tools: Jeliot 3, SRec, jGrasp and DDD. Visualizations that they produce will be reviewed and analyzed and will be mentioned possible places for their application. A...

  20. Visual Search Deficits Are Independent of Magnocellular Deficits in Dyslexia

    Wright, Craig M.; Conlon, Elizabeth G.; Dyck, Murray

    2012-01-01

    The aim of this study was to investigate the theory that visual magnocellular deficits seen in groups with dyslexia are linked to reading via the mechanisms of visual attention. Visual attention was measured with a serial search task and magnocellular function with a coherent motion task. A large group of children with dyslexia (n = 70) had slower…