966 resultados para Visual Impairment
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Purpose: Previous studies of the visual outcome in bilateral non-arteritic anterior ischemic optic neuropathy (NAION) have yielded conflicting results, specifically regarding congruity between fellow eyes. Prior studies have used measures of acuity and computerized perimetry but none has compared Goldmann visual field outcomes between fellow eyes. In order to better define the concordance of visual loss in this condition, we reviewed our cases of bilateral sequential NAION, including measures of visual acuity, pupillary function and both pattern and severity of visual field loss.Methods: We performed a retrospective chart review of 102 patients with a diagnosis of bilateral sequential NAION. Of the 102 patients, 86 were included in the study for analysis of final visual outcome between the affected eyes. Visual function was assessed using visual acuity, Goldmann visual fields, color vision and RAPD. A quantitative total visual field score and score per quadrant was analyzed for each eye using the numerical Goldmann visual field scoring method previously described by Esterman and colleagues. Based upon these scores, we calculated the total deviation and pattern deviation between fellow eyes and between eyes of different patients. Statistical significance was determined using nonparametric tests.Results: A statistically significant correlation was found between fellow eyes for multiple parameters, including logMAR visual acuity (P = 0.0101), global visual field (P = 0.0001), superior visual field (P = 0.0001), and inferior visual field (P = 0.0001). In addition, the mean deviation of both total (P = 0.0000000007) and pattern (P = 0.000000004) deviation analyses was significantly less between fellow eyes ("intra"-eyes) than between eyes of different patients ("inter"-eyes).Conclusions: Visual function between fellow eyes showed a fair to moderate correlation that was statistically significant. The pattern of vision loss was also more similar in fellow eyes than between eyes of different patients. These results may help allow better prediction of visual outcome for the second eye in patients with NAION. These findings may also be useful for evaluating efficacy of therapeutic interventions.
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Quase tudo do pouco que sabemos sobre o conhecimento produzido nos chega pelos meios de informação e comunicação. Estes, por sua vez, também constroem imagens do mundo. Imagens para deleitar, entreter, vender, sugerindo o que devemos vestir, comer, aparentar, pensar. Em nossa sociedade contemporânea discute-se a necessidade de uma alfabetização visual, que se expressa em várias designações, como leitura de imagens e compreensão crítica da cultura visual. Freqüentes mudanças de expressões e conceitos dificultam o entendimento dessas propostas para o currículo escolar, assim como a própria definição do professor ou professora que será responsável por esse conhecimento e seu referencial teórico. Este artigo apresenta os conceitos que fundamentam as propostas da leitura de imagens e cultura visual, sinalizando suas proximidades e distâncias. Contrasta alguns referenciais teóricos da antropologia, arte, educação, história, sociologia, e sugere linhas de trabalho em ambientes de aprendizagem para que se possa refletir a permanente formação docente.
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Time is embedded in any sensory experience: the movements of a dance, the rhythm of a piece of music, the words of a speaker are all examples of temporally structured sensory events. In humans, if and how visual cortices perform temporal processing remains unclear. Here we show that both primary visual cortex (V1) and extrastriate area V5/MT are causally involved in encoding and keeping time in memory and that this involvement is independent from low-level visual processing. Most importantly we demonstrate that V1 and V5/MT come into play simultaneously and seem to be functionally linked during interval encoding, whereas they operate serially (V1 followed by V5/MT) and seem to be independent while maintaining temporal information in working memory. These data help to refine our knowledge of the functional properties of human visual cortex, highlighting the contribution and the temporal dynamics of V1 and V5/MT in the processing of the temporal aspects of visual information.
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Objective: To assess whether a downhill walking training programme is more effective than the same amount of training applied uphill in chronic stroke survivors. Design: Randomized, single-blind study. Setting: Outpatient rehabilitation service. Methods: Thirty-eight adults with hemiplegia from stroke lasting more than three months were randomly allocated to one of the two groups: 'UP' - 45 minutes of physical therapy + 30 minutes of treadmill with 5% ascending slope; and 'DOWN' - 45 minutes of physical therapy + 30 minutes of treadmill with 5% descending slope. Both groups were treated 5 times a week for six weeks. Patients were evaluated before treatment, at the end of treatment and after three months. Outcome measures: Primary outcome measure was the number of patients showing an improvement in 6-minute walking test (6MWT) greater than 50 m. Secondary outcome measures were: (1) number of patients showing a clinically relevant improvement of gait speed during 10-m walking test (10mWT); (2) number of patients showing an improvement in timed up and go (TUG) greater than minimal detectable change. Results: Both groups had a significant improvement after treatment and at follow-up. At the end of treatment, compared to UP group, more patients in the DOWN group showed clinically significant improvements in primary and secondary outcomes (16/19 patients for 6MWT, 11/19 patients for 10mWT and 9/19 patients for TUG compared with 3/19, 4/19 and 2/19 patients, respectively, P < 0.01). At follow-up, results were similar except for 10mWT. Conclusions: In chronic stroke patients, downhill treadmill training produces a bigger effect than uphill training.
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Vision provides a primary sensory input for food perception. It raises expectations on taste and nutritional value and drives acceptance or rejection. So far, the impact of visual food cues varying in energy content on subsequent taste integration remains unexplored. Using electrical neuroimaging, we assessed whether high- and low-calorie food cues differentially influence the brain processing and perception of a subsequent neutral electric taste. When viewing high-calorie food images, participants reported the subsequent taste to be more pleasant than when low-calorie food images preceded the identical taste. Moreover, the taste-evoked neural activity was stronger in the bilateral insula and the adjacent frontal operculum (FOP) within 100 ms after taste onset when preceded by high- versus low-calorie cues. A similar pattern evolved in the anterior cingulate (ACC) and medial orbitofrontal cortex (OFC) around 180 ms, as well as, in the right insula, around 360 ms. The activation differences in the OFC correlated positively with changes in taste pleasantness, a finding that is an accord with the role of the OFC in the hedonic evaluation of taste. Later activation differences in the right insula likely indicate revaluation of interoceptive taste awareness. Our findings reveal previously unknown mechanisms of cross-modal, visual-gustatory, sensory interactions underlying food evaluation.
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Macroscopic features such as volume, surface estimate, thickness and caudorostral length of the human primary visual cortex (Brodman's area 17) of 46 human brains between midgestation and 93 years were studied by means of camera lucida drawings from serial frontal sections. Individual values were best fitted by a logistic function from midgestation to adulthood and by a regression line between adulthood and old age. Allometric functions were calculated to study developmental relationships between all the features. The three-dimensional shape of area 17 was also reconstructed from the serial sections in 15 cases and correlated with the sequence of morphological events. The sulcal pattern of area 17 begins to develop around 21 weeks of gestation but remains rather simple until birth, while it becomes more convoluted, particularly in the caudal part, during the postnatal period. Until birth, a large increase in cortical thickness (about 83% of its mean adult value) and caudorostral length (69%) produces a moderate increase in cortical volume (31%) and surface estimate (40%) of area 17. After birth, the cortical volume and surface undergo their maximum growth rate, in spite of a rather small increase in cortical thickness and caudorostral length. This is due to the development of the pattern of gyrification within and around the calcarine fissure. All macroscopic features have reached the mean adult value by the end of the first postnatal year. With aging, the only features to undergo significant regression are the cortical surface estimate and the caudorostral length. The total number of neurons in area 17 shows great interindividual variability at all ages. No decrease in the postnatal period or in aging could be demonstrated.
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L'objectiu d'aquest article és promoure la incorporació de llibres il-lustrats a l'espai docent, tot defensant la interacció entre escola i entorn. Amb aquesta intenció es presenta una experiència docent que es du a terme a les classes de Didàctica de l'Educació Visual i Plàstica (UB), en la formació inicial del professorat d'educació primària, que empra el llibre il-lustrat com a eina docent. Es tracta d'un corpus d'obres de gran qualitat, la temàtica dels quals està relacionada amb el fet artístic i la seva didàctica. Amb l'ús a les aules universitàries d'aquest tipus de llibres es volen aconseguir principalment tres objectius: donar-los a conèixer als futurs mestres per a la seva formació i perquè els puguin compartir amb els seus futurs alumnes a les aules d'Educació Primària; tractar temes específics de l'àrea de plàstica, i fomentar la reflexió sobre la pràctica docent o altres temes específics.
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El presente trabajo es el resultado de un año de investigación de campo y de estudio bibliográfico, que se formalizó en un proyecto educativo dirigido a alumnos de 3 de secundaria en la área de educación visual y plástica. " Las manos" , título del proyecto, se presentó como una alternativa en la didáctica de la educación visual y plástica cuando se plantea desde un aprendizaje lineal, desde un modelo. El planteamiento consistió en potenciar la comprensión y expresión artísticas a partir de la interrelación de otras áreas de conocimiento con la visual y plástica para sensibilizar al alumno en la importancia que tiene el proceso en el acto creativo. Valorar el proceso facilitó la asimilación de conceptos como figuración, abstracción y síntesis tan importantes para entender el hecho artístico. La valoración positiva del proyecto no pretende contraponer dos metodologías diferentes: la lineal con modelos y la que se presenta en espiral, inductiva, con referentes que no tienen que ser necesariamente visuales. Las dos opciones pueden actuar en simbiosis siempre que el alumno sepa percibir el significado que quiere dar a su obra y que todo no quede en una pura representación decorativa.
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L'era de la comunicació acara la comunitat educativa davant de nous reptes, especialment en l'àmbit de la cultura visual. La cultura visual es manifesta avui arreu i no hi ha àmbit ni familiar ni social ni educatiu que no en participi. Més enllà de la visualització i experimentació d'alguns procediments artístics canònics, l'ensenyament de les arts visuals i plàstiques observa la necessitat d'ampliar el seu radi d'acció, reflexió i anàlisi de manera coparticipada. Un repàs a la trajectòria històrica de l'aprenentatge artístic dóna peu a algunes preguntes rellevants com ara, quins aprenentatges per a quines competències? Per a quina societat i amb quins instruments cal educar els infants? Quines inèrcies i teories s¿hereten del passat i quin lloc cal que tinguin en el futur? Quines aportacions cognitives o empíriques permetrien una renovació positiva en l'àmbit de l¿educació visual i plàstica? Són preguntes difícils però peremptòries si no es vol girar l'esquena a l'evidència dels canvis comunicatius i socials del nostre temps.
Resumo:
Purpose: Complete achromatopsia is a rare autosomal recessive disease due to CNGA3, CNGB3, GNAT2 and PDE6C mutations. We studied a large consanguineous Tunisian family including twelve individuals.Methods: Ophthalmic evaluation included a full clinical examination, color vision testing, optical coherence tomography and electroretinography. Linkage analysis using microsatellite markers flanking CNGA3, CNGB3, GNAT2 and PDE6C genes was performed. Mutations were screened by direct sequencing.Results: In all affected subjects, acuity ranged from 20/50 to 20/200. Fundus examination was normal except for two patients who had respectively 4 mm and 5 mm diameters of peripheral congenital hypertrophy. Likewise retinal layers exploration by OCT revealed no change in the thickness of the central retina. Color Vision with 100 Hue Farnsworth test described a profound color impairment along all three axes of color vision. The haplotype analysis of GNAT2 markers revealed that all affected offspring were homozygous by descent for the four polymorphic markers. The maximum lod score value, 4.33, confirmed the evidence for linkage to the GNAT2 gene.A homozygous novel nonsense mutation R313X was identified segregating with an identical GNAT2 haplotype in all affected subjects. This mutation could interrupt interaction with photoactivated rhodopsin, resulting in a failure of visual transduction. In fact, ERG showed a clearly abolished photopic b-wave and flicker responses with no residual cone function justifying the severe GNAT2 achromatopsia phenotype.Conclusions: This is the first report of the clinical and genetic investigation of complete achromatopsia in North Africa and of the largest family with recessive achromatopsia involving GNAT2, thus providing a unique opportunity for genotype phenotype correlation for this extremely rare condition.