90 resultados para Human visual processing
em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"
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Studies of the effect of ethanol on human visual evoked potentials are rare and usually involve chronic alcoholic patients. The effect of acute ethanol ingestion has seldom been investigated. We have studied the effect of acute alcoholic poisoning on pattern-reversal visual evoked potentials (PR-VEP) and flash light visual evoked potentials (F-VEP) in 20 normal volunteers. We observed different effects with ethanol: statistically significant prolonged latencies of F-VEP after ingestion, and no significant differences in the latencies of the PR-VEP components. We hypothesize a selective ethanol effect on the afferent transmission of rods, mainly dependent on GABA and glutamatergic neurotransmission, influencing F-VEP latencies, and no effect on cone afferent transmission, as alcohol doesn't influence PR-VEP latencies.
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Objective: To make individual assessments using automated quantification methodology in order to screen for perfusion abnormalities in cerebral SPECT examinations among a sample of subjects with OCD. Methods: Statistical parametric mapping (SPM) was used to compare 26 brain SPECT images from patients with OCD individually with an image bank of 32 normal subjects, using the statistical threshold of p < 0.05 (corrected for multiple comparisons at the level of individual voxels or clusters). The maps were analyzed, and regions presenting voxels that remained above this threshold were sought. results: Six patients from a sample of 26 OCD images showed abnormalities at cluster or voxel level, considering the criteria described above, which represented 23.07%. However, seven images from the normal group of 32 were also indicated as cases of perfusional abnormality, representing 21.8% of the sample. Conclusion: The automated quantification method was not considered to be a useful tool for clinical practice, for analyses complementary to visual inspection.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
The phonological and visual basis of developmental dyslexia in Brazilian Portuguese reading children
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Evidence from opaque languages suggests that visual attention processing abilities in addition to phonological skills may act as cognitive underpinnings of developmental dyslexia. We explored the role of these two cognitive abilities on reading fluency in Brazilian Portuguese, a more transparent orthography than French or English. Sixty-six children with developmental dyslexia and normal Brazilian Portuguese children participated. They were administered three tasks of phonological skills (phoneme identification, phoneme, and syllable blending) and three visual tasks (a letter global report task and two non-verbal tasks of visual closure and visual constancy). Results show that Brazilian Portuguese children with developmental dyslexia are impaired not only in phonological processing but further in visual processing. The phonological and visual processing abilities significantly and independently contribute to reading fluency in the whole population. Last, different cognitively homogeneous subtypes can be identified in the Brazilian Portuguese population of children with developmental dyslexia. Two subsets of children with developmental dyslexia were identified as having a single cognitive disorder, phonological or visual; another group exhibited a double deficit and a few children showed no visual or phonological disorder. Thus the current findings extend previous data from more opaque orthographies as French and English, in showing the importance of investigating visual processing skills in addition to phonological skills in children with developmental dyslexia whatever their language orthography transparency.
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We are included in a society where the use of the Internet became very important to our everyday life. The relationships nowadays usually happen through technological devices instead of face to face contact, for instance, Internet forums where people can discuss online. However, the global analysis is a big challenge, due to the large amount of data. This work investigates the use of visual representations to support an exploratory analysis of contents in messages from discussions forums. This analysis considers the thematic and the chronology. The target forums refer to the educational area and the analysis happens manually, i.e. by direct reading message-by-message. The proprieties of perception and cognition of the human visual system allow a person the capacity to conduct high-level tasks in information extraction from a graphical or visual representation of data. Therefore, this work was based on Visual Analytics, an area that aims create techniques that amplify these human abilities. For that reason we used software that creates a visualization of data from a forum. This software allows a forum content analysis. But, during the work, we identified the necessity to create a new tool to clean the data, because the data had a lot of unnecessary information. After cleaning the data we created a new visualization and held an analysis seeking a new knowledge. In the end we compared the new visualization with the manual analysis that had been made. Analyzing the results, it was evident the potential of visualization use, it provides a better correlation between the information, enabling the acquisition of new knowledge that was not identified in the initial analysis, providing a better use of the forum content
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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O estudo tem como objetivo caracterizar e comparar o desempenho cognitivo-linguístico de escolares com distúrbio de aprendizagem com escolares com bom desempenho acadêmico. Participaram 40 escolares de 8 a 12 anos de idade, de 2ª a 4ª séries do Ensino Fundamental de escolas municipais da cidade de Marília - SP, divididos em GI (escolares com bom desempenho acadêmico) e GII (escolares com distúrbio de aprendizagem). Como procedimento foi utilizado o Teste de Desempenho Cognitivo-Linguístico, versões coletiva e individual. Os resultados evidenciaram desempenho superior do GI em relação ao GII nas habilidades de leitura, escrita, velocidade de processamento, processamento auditivo e visual. Concluiu-se que o desempenho inferior do GII nas habilidades indica uma limitação no desempenho linguístico desses escolares se comparados com os do GI, exceto na habilidade de consciência fonológica, em que, os grupos apresentaram dificuldades semelhantes, sugerindo que essa dificuldade não seja específica de escolares com distúrbio de aprendizagem.
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Fifty-four extracted human mandibular molars were embedded and sectioned at two levels. The reassembled mesial root canals were prepared with stainless-steel hand K-files (Flexofiles) and either Nitiflex or Mity nickel-titanium hand K-files using a push-pull anticurvature filing technique. Each of the three experimental groups contained 36 mesial canals randomly distributed. Superimposed pre- and postinstrumentation cross-sectional root images were magnified using a stereomicroscope and transferred to a computer for measurement and statistical analysis. The direction and extent of canal center movement were evaluated. At the apical level, the groups produced no significant difference of direction of canal center movement. In cervical sections, all groups tended to move in a distolingual direction. The three groups, however, produced no significant difference in the cervical sections in the extent of canal center movement. In apical sections, Nitiflex produced the least canal center movement. Copyright © 1999 by The American Association of Endodontists.
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The orbitofrontal cortex (OfC) is a heterogeneous prefrontal sector selectively connected with a wide constellation of other prefrontal, limbic, sensory and premotor areas. Among the limbic cortical connections, the ones with the bippocampus and parabippocampal cortex are particularly salient. Sensory cortices connected with the OfC include areas involved in olfactory, gustatory, somatosensory, auditory and visual processing. Subcortical structures with prominent OfC connections include the amygdala, numerous thalamic nuclei, the striatum, hypothalamus, periaqueductal gray matter, and biochemically specific cell groups in the basal forebrain and brainstem. Architectonic and connectional evidence supports parcellation of the OfC. The rostrally placed isocortical sector is mainly connected with isocortical areas, including sensory areas of the auditory, somatic and visual modalities, whereas the caudal non-isocortical sector is principally connected with non-isocortical areas, and, in the sensory domain, with olfactory and gustatory areas. The connections of the isocortical and non- isocortical orbital sectors with the amygdala, thalamus, striatum, hypotbalamus and periaqueductal gray matter are also specific. The medial sector of the OfC is selectively connected with the bippocampus, posterior parabippocampal cortex, posterior cingulate and retrosplenial areas, and area prostriata, while the lateral orbitofrontal sector is the most heavily connected with sensory areas of the gustatory, somatic and visual modalities, with premotor regions, and with the amygdala.
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The purpose of this investigation was to evaluate the dentoalveolar and skeletal cephalometric changes produced by the Fränkel appliance in individuals with a Class II, division 1 malocclusion. Lateral cephalograms of 44 patients of both sexes were divided in two groups of 22 each. The control group was comprised of untreated Class II children with an initial mean age of eight years and seven months who were followed without treatment for a period of 13 months. The Fränkel group had an initial mean age of nine years and was treated for a mean period of 17 months. Lateral cephalometric headfilms of each patient were obtained at the beginning and end of treatment. The Fränkel appliance produced no significant changes in maxillary growth during the evaluation period, while a statistically significant increase in mandibular length was observed. The maxillomandibular relationship improved mostly because of an increase in mandibular length. In addition, there were no statistically significant differences in the craniofacial growth direction between the Fränkel and the control group, both showing a slight downward rotation of the palatal plane. The Fränkel appliance produced a labial tipping of the lower incisors and a lingual inclination of the upper incisors as well as a significant increase in mandibular posterior dentoalveolar height. It was concluded that the main effects of the Fränkel appliance during this time period were mostly dentoalveolar with a smaller but significant skeletal mandibular effect.
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The aim of this study was to evaluate the diagnostic agreement of conventional panoramic radiographs and their inverted scanned images in the detection of the mandibular canal and mental foramen. A total of 77 panoramic radiographs obtained from the files of totally edentulous patients were used. Digitization was done by means of a scanner with brightness and contrast adjustment, as well as image inversion. The extension of mandibular canal was divided into anterior, middle, and posterior regions, and the presence of a radiopaque line that characterized the mandibular canal was classified according to a 5-point confidence scale. The mental foramen was classified in 4 types: continuous, separated, diffuse, and unidentified. Both conventional and inverted scanned panoramic radiographs were evaluated by 3 calibrated implantologists at 2 distinct moments with a minimum interval of 10 days between them. Intraexaminer agreement was evaluated by Kappa statistics by point and by 95% confidence interval. Because the intraexaminer level of agreement was low, interexaminer agreements could not be carried out. The results showed a substantial (in 2 situations), moderate (in 16 situations), and fair (in 18 situations) intraexaminer agreement for mandibular canal and a substantial (in 1 situation), fair (in 1 situation), and moderate (in 10 situations) intraeaminer agreement for mental foramen. There were no statistically significant differences in most instances. In conclusion, the diagnostic agreement of conventional and inverted scanned panoramic radiographs for detection of mandibular canal and mental foramen was low.
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This article introduces a new method for 3-dimensional dental cast analysis, by using a mechanical 3-dimensional digitizer, MicroScribe 3DX (Immersion, San Jose, Calif), and TIGARO software (not yet released, but available from the author at hayasaki@dent.kyushu-u.ac.jp). By digitizing points on the model, multiple measurements can be made, including tooth dimensions; arch length, width, and perimeter; curve of Spee; overjet and overbite; and anteroposterior discrepancy. The bias of the system can be evaluated by comparing the distance between 2 points as determined by the new system and as measured with digital calipers. Fifteen pairs of models were measured digitally and manually, and the bias was evaluated by comparing the variances of both methods and checking for the type of error obtained by each method. No systematic errors were found. The results showed that the method is accurate, and it can be applied to both clinical practice and research. Copyright © 2005 by the American Association of Orthodontists.
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Teledermatology is the area of Telemedicine that studies the application of telecommunication and information technology to dermatology practice without the presence of a specialist. It is a potential manner to deliver health planning, research, education, clinical meetings, second medical opinions and dermatological care to populations who cannot easily travel. The evolution, cost reduction and dissemination of telecommunication and information technology have enabled the implementation of low cost and comprehensive teledermatology systems to support clinical practice all over the world. © 2005 by Anais Brasileiros de Dermatologia.
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Purpose: To determine palpebral dimensions and development in Brazilian children using digital images. Methods: An observational study was performed measuring eyelid angles, palpebral fissure area and interpupillary distance in 220 children aged from 4 to 72 months. Digital images were obtained with a Sony Lithium movie camera (Sony DCR-TRV110, Brazil) in frontal view from awake children in primary ocular position; the object of observation was located at pupil height. The images were saved to tape, transferred to a Macintosh G4 (Apple Computer Inc., USA) computer and processed using NIH 1.58 software (NTIS, 5285 Port Royal Rd., Springfield, VA 22161, USA). Data were submitted to statistical analysis. Results: All parameters studied increased with age. The outer palpebral angle was greater than the inner, and palpebral fissure and angles showed greater changes between 4 and 5 months old and at around 24 to 36 months. Conclusion: There are significant variations in palpebral dimensions in children under 72 months old, especially around 24 to 36 months. Copyright © 2006 Informa Healthcare.
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The purpose of this study was to evaluate the effectiveness of subgingival application of Carisolv™ gel as an adjunctive therapy to scaling and root planing (SRP) on calculus removal compared to conventional instrumentation. Forty-five teeth requiring extraction due to severe periodontal disease were randomized to the following treatments: 1) SRP alone; 2) placebo gel + SRP; 3) Carisolv™ gel + SRP. Either test or placebo gel was applied subgingivally for 1 min and then the root were instrumented until a smooth and calculus-free surface was achieved. Instrumentation time and the number of strokes required were recorded. After extraction, the efficacy of root surface instrumentation was measured by percentage of remaining calculus. There was no statistically significant difference (p>0.05) between the treatment groups regarding either time required for instrumentation or the percentage of residual calculus. The subgingival application of Carisolv™ gel prior to SRP did not provide any additional benefit to root instrumentation compared to scaling and root planing alone.