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Estudo comparativo entre a relação do hemisfério acometido no acidente vascular encefálico e a evolução funcional em indivíduos destros; Comparative study on the relationship between stroke hemisphere and functional evolution in right-handed individuals

VOOS, MC; RIBEIRO DO VALLE, LE
Fonte: Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia Publicador: Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
46.11%
OBJETIVO: O hemisfério esquerdo é dominante para o controle motor e o direito para a orientação espacial. Este estudo visou testar as hipóteses de que a lesão à esquerda causa maior prejuízo da movimentação voluntária e a lesão à direita resulta em perda na atenção espacial e no controle postural. Indivíduos com lesão à esquerda foram comparados com indivíduos com lesão à direita, com relação ao comprometimento inicial e recuperação três meses pós-lesão. MATERIAIS E MÉTODOS: Vinte e dois indivíduos destros com lesão isquêmica no território da artéria cerebral média (11 à esquerda e 11 à direita) foram avaliados mensalmente nos três primeiros meses pós-lesão em termos de sensibilidade, tônus, força, postura, marcha, independência funcional e atenção espacial. RESULTADOS: Com relação ao comprometimento inicial, não houve diferença na sensibilidade, tônus, força, postura e atenção dos grupos. O grupo com lesão à esquerda apresentou pior desempenho inicial nos testes de marcha e de independência funcional. Com relação à taxa de recuperação, não houve diferenças na sensibilidade, tônus, força, postura, atenção e independência funcional dos dois grupos. Porém, a taxa de recuperação da marcha do grupo com lesão à esquerda foi inferior à do outro grupo. CONCLUSÕES: Foi confirmada a hipótese de que a lesão à esquerda causa maior comprometimento da movimentação voluntária...

Abnormal Left and Right Amygdala-Orbitofrontal Cortical Functional Connectivity to Emotional Faces: State Versus Trait Vulnerability Markers of Depression in Bipolar Disorder

VERSACE, Amelia; THOMPSON, Wesley K.; ZHOU, Donli; ALMEIDA, Jorge R. C.; HASSEL, Stefanie; KLEIN, Crystal R.; KUPFER, David J.; PHILLIPS, Mary L.
Fonte: ELSEVIER SCIENCE INC Publicador: ELSEVIER SCIENCE INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.04%
Background: Amygdala-orbitofrontal cortical (OFC) functional connectivity (FC) to emotional stimuli and relationships with white matter remain little examined in bipolar disorder individuals (BD). Methods: Thirty-one BD (type 1; n = 17 remitted; n = 14 depressed) and 24 age- and gender-ratio-matched healthy individuals (HC) viewed neutral, mild, and intense happy or sad emotional faces in two experiments. The FC was computed as linear and nonlinear dependence measures between amygdala and OFC time series. Effects of group, laterality, and emotion intensity upon amygdala-OFC FC and amygdala-OFC FC white matter fractional anisotropy (FA) relationships were examined. Results: The BD versus HC showed significantly greater right amygdala-OFC FC (p <= .001) in the sad experiment and significantly reduced bilateral amygdala-OFC FC (p = .007) in the happy experiment. Depressed but not remitted female BD versus female HC showed significantly greater left amygdala-OFC FC (p = .001) to all faces in the sad experiment and reduced bilateral amygdala-OFC FC to intense happy faces (p = .01). There was a significant nonlinear relationship (p = .001) between left amygdala-OFC FC to sad faces and FA in HC. In BD, antidepressants were associated with significantly reduced left amygdala-OFC FC to mild sad faces (p = .001). Conclusions: In BD...

"Estudo das vias auditivas eferentes em indivíduos com zumbido" ; Study of efferent auditory pathways in subjects with tinnitus

Favero, Mariana Lopes
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 30/03/2004 PT
Relevância na Pesquisa
36.14%
Uma ativação do trato olivococlear medial reduz a amplitude das emissões otoacústicas de forma lateralizada, com um predomínio à direita. Pessoas com zumbido teriam uma disfunção do reflexo eferente, mas esses resultados não foram comprovados em todas as pesquisas. Curiosamente, estas pesquisas não valorizam a lateralidade eferente. Comparamos a supressão na orelha direita de pessoas com e sem zumbido e a lateralidade do sistema eferente pela análise da supressão à direita e à esquerda no grupo sem zumbido. Concluímos que há relação entre zumbido e não supressão e que à direita, a supressão é maior ; An activation of the medial olivocochlear tract reduces the amplitude of otoacoustic emissions with predominance of the right side. Subjects with tinnitus would have an abnormality of the suppressing reflex, but such results have not been confirmed yet in any study. Curiously, such studies did not value the functional laterality. We compared right ear suppression of people with and without tinnitus, and the suppression on the right and on the left in the group without tinnitus. We concluded that there was a relation between tinnitus and absent suppression of otoacoustic emissions and right ear suppression was more marked.

Inferência do tempo de atividade neural a partir do efeito BOLD em ressonância magnética funcional; Inference of neural activity time from BOLD effect in functional magnetic resonance imaging

Biazoli Junior, Claudinei Eduardo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 01/04/2011 PT
Relevância na Pesquisa
56.32%
A inferência do curso temporal da atividade neural a partir do efeito BOLD é um importante problema, ainda em aberto. A forma da curva BOLD não reflete diretamente as características temporais da atividade eletrofisiológica dos neurônios. Nessa tese, é introduzido o conceito de tempo de processamento neural (TPN) como um dos parâmetros do modelo biofísico da função de resposta hemodinâmica (HRF). O objetivo da introdução desse conceito é obter estimativas mais acuradas da duração da atividade neural a partir do efeito BOLD, que possui auto grau de nãolinearidade. Duas formas de estimar os parâmetros do modelo do efeito BOLD foram desenvolvidas. A validade e aplicabilidade do conceito de TPN e das rotinas de estimação foram avaliadas por simulações computacionais e análise de séries temporais experimentais. Os resultados das simulações e da aplicação foram comparados com medidas da forma da HRF. O experimento analisado consistiu em um paradigma de tomada de decisão na presença de distratores emocionais. Esperase que o TPN em áreas sensoriais primárias seja equivalente ao tempo de apresentação de estímulos. Por outro lado, o TPN em áreas relacionadas com a tomada de decisão deve ser menor que a duração dos estímulos. Além disso...

Nova metodologia de Doppler transcraniano funcional durante tarefa motora unimanual; New methodology for functional transcranial Doppler during an unimanual

Haratz, Salo Semelmann
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 30/06/2014 PT
Relevância na Pesquisa
46.13%
INTRODUÇÃO: O Doppler Transcraniano funcional pode avaliar mudanças na velocidade do fluxo sanguíneo encefálico associadas a tarefas cognitivas e/ou sensitivo-motoras. Mede de maneira indireta a atividade metabólica de regiões cerebrais, segundo o princípio do acoplamento neurovascular. Os objetivos deste estudo foram: desenvolver um novo método de análise de Doppler transcraniano funcional para análise da lateralização hemisférica e verificar a capacidade deste novo método em diferenciar a lateralização hemisférica durante a execução de uma tarefa motora unimanual por indivíduos saudáveis. Adicionalmente, a lateralização hemisférica foi correlacionada com a preferência manual nestes indivíduos. MÉTODOS: Treze indivíduos saudáveis foram submetidos a um exame de Doppler transcraniano funcional durante uma prova de ativação motora manual (oposição de dedos). As sessões de Doppler transcraniano funcional foram realizadas com aparelho Doppler-Box Transcranial Doppler Unit. A prova manual compreendeu uma sequência de movimentos de oposição do primeiro e segundo dedos (thumb-tofinger opposition movement) realizado por uma mão e depois pela outra, em uma frequência de 1 movimento por segundo (1Hz) fornecida por um metrônomo digital. Durante a execução dos movimentos...

Identificação de regiões cerebrais de linguagem : estudo de ressonância magnética funcional em pacientes com epilepsia refratária de lobo temporal; Identifying language cerebral functions : a study of functional magnetic resonance imaging in patients with refractory temporal lobe epilepsy

Fontoura, Denise Ren da; Branco, Daniel de Moraes; Anés, Maurício; Costa, Jaderson Costa da; Portuguez, Mirna Wetters
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
36.04%
Objetivo: Identificar as regiões cerebrais responsáveis pelas funções de linguagem através de Ressonância Magnética funcional (RMf) em pacientes com epilepsia refratária de lobo temporal. Metodologia: Foi realizada RMf utilizando-se o paradigma de geração de verbos. Os pacientes ouviam palavras concretas e eram orientados a pensar na sua finalidade, sem verbalizar (ex: faca-cortar). Utilizou-se o cálculo de índice de lateralidade (IL) e a verificação do grau de ativação das áreas classicamente envolvidas na linguagem. Resultados e conclusões: Constatou-se que 92,3% dos pacientes investigados apresentaram linguagem em hemisfério esquerdo, e 7,7%, linguagem mista. Observou-se que existe maior freqüência de pacientes com ativação nas regiões de Broca esquerda, Córtex Pré-motor esquerdo, área de Wernicke esquerda e Córtex Auditivo esquerdo.; Purpose: The purpose of this study was to identify the brain regions for language functions with the functional Magnetic Resonance Image (fMRI) in patients suffering from intractable temporal lobe epilepsy. Methods: During fMRI, patients performed a verb-generation task. They heard concrete words through headphones and were asked to think of their utility (e.g. pencil – to write)...

Uncoupled leftward asymmetries for planum morphology and functional language processing

Eckert, Mark A.; Leonard, Christiana M.; Possing, Edward T.; Binder, Jeffery R.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.64%
Explanations for left hemisphere language laterality have often focused on hemispheric structural asymmetry of the planum temporale. We examined the association between an index of language laterality and brain morphology in 99 normal adults whose degree of laterality was established using a functional MRI single-word comprehension task. The index of language laterality was derived from the difference in volume of activation between the left and right hemispheres. Planum temporale and brain volume measures were made using structural MRI scans, blind to the functional data. Although both planum temporale asymmetry (t(1,99) = 6.86, p < .001) and language laterality (t(1,99) = 15.26, p < .001) were significantly left hemisphere biased, there was not a significant association between these variables (r(99) = .01, ns). Brain volume, a control variable for the planum temporale analyses, was related to language laterality in a multiple regression (β = −.30, t = −2.25, p < .05). Individuals with small brains were more likely to demonstrate strong left hemisphere language laterality. These results suggest that language laterality is a multidimensional construct with complex neurological origins.

Function Lateralization via Measuring Coherence Laterality

Wang, Ze; Mechanic-Hamilton, Dawn; Pluta, John; Glynn, Simon; Detre, John A.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.53%
A data-driven approach for lateralization of brain function based on the spatial coherence difference of functional MRI (fMRI) data in homologous regions-of-interest (ROI) in each hemisphere is proposed. The utility of using coherence laterality (CL) to determine function laterality was assessed first by examining motor laterality using normal subjects’ data acquired both at rest and with a simple unilateral motor task and subsequently by examining mesial temporal lobe memory laterality in normal subjects and patients with temporal lobe epilepsy. The motor task was used to demonstrate that CL within motor ROI correctly lateralized functional stimulation. In patients with unilateral epilepsy studied during a scene-encoding task, CL in a hippocampus-parahippocampus-fusiform (HPF) ROI was concordant with lateralization based on task activation, and the CL index (CLI) significantly differentiated the right side group to the left side group. By contrast, normal controls showed a symmetric HPF CLI distribution. Additionally, similar memory laterality prediction results were still observed using CL in epilepsy patients with unilateral seizures after the memory encoding effect was removed from the data, suggesting the potential for lateralization of pathological brain function based on resting fMRI data. A better lateralization was further achieved via a combination of the proposed approach and the standard activation based approach...

Language Laterality in Autism Spectrum Disorder and Typical Controls: A Functional, Volumetric, and Diffusion Tensor MRI Study

Knaus, Tracey A.; Silver, Andrew M.; Kennedy, Meaghan; Lindgren, Kristen A.; Dominick, Kelli C.; Siegel, Jeremy; Tager-Flusberg, Helen
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.47%
Language and communication deficits are among the core features of autism spectrum disorder (ASD). Reduced or reversed asymmetry of language has been found in a number of disorders, including ASD. Studies of healthy adults have found an association between language laterality and anatomical measures but this has not been systematically investigated in ASD. The goal of this study was to examine differences in gray matter volume of perisylvian language regions, connections between language regions, and language abilities in individuals with typical left lateralized language compared to those with atypical (bilateral or right) asymmetry of language functions. 14 adolescent boys with ASD and 20 typically developing adolescent boys participated, including equal numbers of left- and right-handed individuals in each group. Participants with typical left lateralized language activation had smaller frontal language region volume and higher fractional anisotropy of the arcuate fasciculus compared to the group with atypical language laterality, across both ASD and control participants. The group with typical language asymmetry included the most right-handed controls and fewest left-handers with ASD. Atypical language laterality was more prevalent in the ASD than control group. These findings support an association between laterality of language function and language region anatomy. They also suggest anatomical differences may be more associated with variation in language laterality than specifically with ASD. Language laterality therefore may provide a novel way of subdividing samples...

Lateralised visual attention is unrelated to language lateralisation, and not influenced by task difficulty – A functional transcranial Doppler study

Rosch, Richard E.; Bishop, Dorothy V.M.; Badcock, Nicholas A.
Fonte: Pergamon Press Publicador: Pergamon Press
Tipo: Artigo de Revista Científica
Publicado em /04/2012 EN
Relevância na Pesquisa
36.55%
Historically, most theoretical accounts of hemispheric specialisation have proposed a single underlying factor that leads to left hemisphere language and right hemisphere visuospatial processing in the majority of people. More recently empirical evidence has started to challenge this view, suggesting lateralisation of language and visuospatial attention are independent. However, so far studies did not control for a possible confound, task difficulty. For this study, 20 healthy right-handed volunteers underwent functional laterality assessment using functional transcranial Doppler ultrasound (fTCD). We assessed laterality using both a word generation task and a novel variation of the visuospatial landmark task that can be adjusted along two dimensions of difficulty (temporal and spatial). The visuospatial laterality measures were highly intercorrelated and unaffected by task difficulty. Furthermore, there was no correlation between visuospatial and verbal lateralisation within individuals – neither qualitatively (in direction of lateralisation), nor quantitatively (in laterality index size). These results substantiate a growing body of evidence suggesting multiple independent biases leading to the hemispheric lateralisation of different cognitive domains...

Functional connectivity and laterality of the motor and sensory components in the volitional swallowing network

Lowell, Soren Y.; Reynolds, Richard C.; Chen, Gang; Horwitz, Barry; Ludlow, Christy L.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.45%
Functional neuroimaging has shown that multiple brain regions are active during volitional swallowing. Little is known, however, about which regions integrate motor execution and sensory feedback in the swallowing system. Although unilateral brain lesions in either hemisphere can produce swallowing deficits, some functional neuroimaging studies indicate that the left hemisphere has greater activation in certain sensory and motor-related swallowing regions. In this study, correlation coefficients were computed for five seed regions during volitional saliva swallowing to determine the functional relationships of these regions with the rest of the brain: the anterior and posterior insula, inferior frontal gyrus (BA44), primary sensory cortex (S1), and primary motor cortex (M1). A laterality index (LI) was derived that accounts for relative differences in total, positive connected voxels for the left/right hemisphere seeds. Clusters of significantly connected voxels were greater from the anterior and posterior insula than from the other three seed regions. Interactions of the insula with other brain regions were greater on the left than on the right during volitional swallowing. Group means showed laterality in the anterior insula (LI = 0.25) and the posterior insula (LI = 0.33). BA44 showed a lesser degree of difference in left versus right hemisphere interactions (LI = 0.12) while S1 did not show lateralization (LI = 0.02) and M1 showed some predominance of interactions in the right hemisphere (LI = −0.19). The greater connectivity from the left hemisphere insula to brain regions within and across hemispheres suggests that the insula is a primary integrative region for volitional swallowing in humans.

Developmental Trajectories of Amygdala and Hippocampus from Infancy to Early Adulthood in Healthy Individuals

Uematsu, Akiko; Matsui, Mie; Tanaka, Chiaki; Takahashi, Tsutomu; Noguchi, Kyo; Suzuki, Michio; Nishijo, Hisao
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 09/10/2012 EN
Relevância na Pesquisa
26.5%
Knowledge of amygdalar and hippocampal development as they pertain to sex differences and laterality would help to understand not only brain development but also the relationship between brain volume and brain functions. However, few studies investigated development of these two regions, especially during infancy. The purpose of this study was to examine typical volumetric trajectories of amygdala and hippocampus from infancy to early adulthood by predicting sexual dimorphism and laterality. We performed a cross-sectional morphometric MRI study of amygdalar and hippocampal growth from 1 month to 25 years old, using 109 healthy individuals. The findings indicated significant non-linear age-related volume changes, especially during the first few years of life, in both the amygdala and hippocampus regardless of sex. The peak ages of amygdalar and hippocampal volumes came at the timing of preadolescence (9–11 years old). The female amygdala reached its peak age about one year and a half earlier than the male amygdala did. In addition, its rate of growth change decreased earlier in the females. Furthermore, both females and males displayed rightward laterality in the hippocampus, but only the males in the amygdala. The robust growth of the amygdala and hippocampus during infancy highlight the importance of this period for neural and functional development. The sex differences and laterality during development of these two regions suggest that sex-related factors such as sex hormones and functional laterality might affect brain development.

Brain reorganization as a function of walking experience in 12-month-old infants: implications for the development of manual laterality

Corbetta, Daniela; Friedman, Denise R.; Bell, Martha Ann
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 21/03/2014 EN
Relevância na Pesquisa
26.49%
Hand preference in infancy is marked by many developmental shifts in hand use and arm coupling as infants reach for and manipulate objects. Research has linked these early shifts in hand use to the emergence of fundamental postural–locomotor milestones. Specifically, it was found that bimanual reaching declines when infants learn to sit; increases if infants begin to scoot in a sitting posture; declines when infants begin to crawl on hands and knees; and increases again when infants start walking upright. Why such pattern fluctuations during periods of postural–locomotor learning? One proposed hypothesis is that arm use practiced for the specific purpose of controlling posture and achieving locomotion transfers to reaching via brain functional reorganization. There has been scientific support for functional cortical reorganization and change in neural connectivity in response to motor practice in adults and animals, and as a function of crawling experience in human infants. In this research, we examined whether changes in neural connectivity also occurred as infants coupled their arms when learning to walk and whether such coupling mapped onto reaching laterality. Electroencephalogram (EEG) coherence data were collected from 43 12-month-old infants with varied levels of walking experience. EEG was recorded during quiet...

Network Construction and Graph Theoretical Analysis of Functional Language Networks in Pediatric Epilepsy

Salah Eddin, Anas
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
Relevância na Pesquisa
35.99%
This dissertation introduces a new approach for assessing the effects of pediatric epilepsy on the language connectome. Two novel data-driven network construction approaches are presented. These methods rely on connecting different brain regions using either extent or intensity of language related activations as identified by independent component analysis of fMRI data. An auditory description decision task (ADDT) paradigm was used to activate the language network for 29 patients and 30 controls recruited from three major pediatric hospitals. Empirical evaluations illustrated that pediatric epilepsy can cause, or is associated with, a network efficiency reduction. Patients showed a propensity to inefficiently employ the whole brain network to perform the ADDT language task; on the contrary, controls seemed to efficiently use smaller segregated network components to achieve the same task. To explain the causes of the decreased efficiency, graph theoretical analysis was carried out. The analysis revealed no substantial global network feature differences between the patient and control groups. It also showed that for both subject groups the language network exhibited small-world characteristics; however, the patient’s extent of activation network showed a tendency towards more random networks. It was also shown that the intensity of activation network displayed ipsilateral hub reorganization on the local level. The left hemispheric hubs displayed greater centrality values for patients...

Dinamometría manual y factores asociados en adolescentes

Andrés Carreira, José María
Fonte: Universidade de Cantabria Publicador: Universidade de Cantabria
Tipo: Dissertação de Mestrado
SPA
Relevância na Pesquisa
36.14%
Introducción: la fuerza muscular medida mediante dinamometría manual es un buen indicador de salud, ya que nos predice el estado de salud presente y futuro. Objetivo: describir la fuerza manual en la adolescencia y relacionarla con la edad y el sexo. Al mismo tiempo analizar qué influencia ejercen diversos factores como el estado nutricional, la lateralidad del individuo, el IMC, el perímetro de la cintura, el vo-lumen del antebrazo y el commuting ejercen su influencia en la fuerza muscular. Personas y métodos: estudio observacional transversal cuya muestra se compu-so de 503 alumnos (268 mujeres y 235 varones) de entre 12 y 17 años. La medición de la fuerza de presión se realizó con un dinamómetro manual digital con agarre ajus-table (Takei 5401). Se midió el peso, la altura, el perímetro de cintura y la longitud del antebrazo junto con sus perímetros distal y proximal. Con estos datos se calculó el Índice de Masa Corporal (IMC) y el volumen del antebrazo. Resultados: la edad, el sexo y el estado nutricional son importantes predictores de la fuerza muscular. Ponemos de manifiesto por primera vez la importancia del vo-lumen del antebrazo en la fuerza muscular de los adolescentes. El aumento del volu-men del antebrazo supone un aumento en la fuerza prensil. Conclusiones: La fuerza máxima se incrementa con la edad...

Reduced corticomotor excitability and motor skills development in children born preterm

Pitcher, J.; Schneider, L.; Burns, N.; Drysdale, J.; Higgins, R.; Ridding, M.; Nettelbeck, T.; Haslam, R.; Robinson, J.
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
35.99%
The mechanisms underlying the altered neurodevelopment commonly experienced by children born preterm, but without brain lesions, remain unknown. While individuals born the earliest are at most risk, late preterm children also experience significant motor, cognitive and behavioural dysfunction from school age, and reduced income and educational attainment in adulthood. We used transcranial magnetic stimulation and functional assessments to examine corticomotor development in 151 children without cerebral palsy, aged 10-13 years and born after gestations of 25-41 completed weeks. We hypothesized that motor cortex and corticospinal development are altered in preterm children, which underpins at least some of their motor dysfunction. We report for the first time that every week of reduced gestation is associated with a reduction in corticomotor excitability that remains evident in late childhood. This reduced excitability was associated with poorer motor skill development, particularly manual dexterity. However, child adiposity, sex and socio-economic factors regarding the child's home environment soon after birth were also powerful influences on development of motor skills. Preterm birth was also associated with reduced left hemisphere lateralization...

Spatio-temporal dynamics and laterality effects of face inversion, feature presence and configuration, and face outline

Marinkovic, Ksenija; Courtney, Maureen G.; Witzel, Thomas; Dale, Anders M.; Halgren, Eric
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.14%
Although a crucial role of the fusiform gyrus (FG) in face processing has been demonstrated with a variety of methods, converging evidence suggests that face processing involves an interactive and overlapping processing cascade in distributed brain areas. Here we examine the spatio-temporal stages and their functional tuning to face inversion, presence and configuration of inner features, and face contour in healthy subjects during passive viewing. Anatomically-constrained magnetoencephalography (aMEG) combines high-density whole-head MEG recordings and distributed source modeling with high-resolution structural MRI. Each person's reconstructed cortical surface served to constrain noise-normalized minimum norm inverse source estimates. The earliest activity was estimated to the occipital cortex at ~100 ms after stimulus onset and was sensitive to an initial coarse level visual analysis. Activity in the right-lateralized ventral temporal area (inclusive of the FG) peaked at ~160 ms and was largest to inverted faces. Images containing facial features in the veridical and rearranged configuration irrespective of the facial outline elicited intermediate level activity. The M160 stage may provide structural representations necessary for downstream distributed areas to process identity and emotional expression. However...

Laterality Patterns of Brain Functional Connectivity: Gender Effects

Tomasi, Dardo; Volkow, Nora D.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em /06/2012 EN
Relevância na Pesquisa
26.45%
Lateralization of brain connectivity may be essential for normal brain function and may be sexually dimorphic. Here, we study the laterality patterns of short-range (implicated in functional specialization) and long-range (implicated in functional integration) connectivity and the gender effects on these laterality patterns. Parallel computing was used to quantify short- and long-range functional connectivity densities in 913 healthy subjects. Short-range connectivity was rightward lateralized and most asymmetrical in areas around the lateral sulcus, whereas long-range connectivity was rightward lateralized in lateral sulcus and leftward lateralizated in inferior prefrontal cortex and angular gyrus. The posterior inferior occipital cortex was leftward lateralized (short- and long-range connectivity). Males had greater rightward lateralization of brain connectivity in superior temporal (short- and long-range), inferior frontal, and inferior occipital cortices (short-range), whereas females had greater leftward lateralization of long-range connectivity in the inferior frontal cortex. The greater lateralization of the male's brain (rightward and predominantly short-range) may underlie their greater vulnerability to disorders with disrupted brain asymmetries (schizophrenia...

Design complexity and strength of laterality are correlated in New Caledonian crows' pandanus tool manufacture

Hunt, Gavin R; Corballis, Michael C; Gray, Russell D
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.47%
Population-level laterality is generally considered to reflect functional brain specialization. Consequently, the strength of population-level laterality in manipulatory tasks is predicted to positively correlate with task complexity. This relationship has not been investigated in tool manufacture. Here, we report the correlation between strength of laterality and design complexity in the manufacture of New Caledonian crows' three pandanus tool designs: wide, narrow and stepped designs. We documented indirect evidence of over 5800 tool manufactures on 1232 pandanus trees at 23 sites. We found that the strength of laterality in tool manufacture was correlated with design complexity in three ways: (i) the strongest effect size among the population-level edge biases for each design was for the more complex, stepped design, (ii) the strength of laterality at individual sites was on average greater for the stepped design than it was for the simpler wide and narrow, non-stepped designs, and (iii) there was a positive, but non-significant, trend for a correlation between the strength of laterality and the number of steps on a stepped tool. These three aspects together indicate that greater design complexity generally elicits stronger lateralization of crows' pandanus tool manufacture.

Efeito do laser de baixa intensidade (660 nm) na regeneração do nervo isquiático lesado em ratos; Effect of low- power laser (660 nm) on regeneration of injured rat sciatic nerve

Barbosa, Rafael Inácio; Marcolino, Alexandre Marcio; Guirro, Rinaldo Roberto de Jesus; Mazzer, Nilton; Barbieri, Cláudio Henrique; Fonseca, Marisa de Cássia Registro
Fonte: Universidade de São Paulo. Faculdade de Medicina Publicador: Universidade de São Paulo. Faculdade de Medicina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; ; Formato: application/pdf
Publicado em 01/12/2010 POR
Relevância na Pesquisa
36.04%
Os nervos periféricos são estruturas que, ao sofrerem lesões, podem originar incapacidades motoras e sensitivas importantes. O laser de baixa intensidade é um dos diversos recursos terapêuticos para promover a regeneração nervosa precoce, mas ainda não há consenso sobre sua utilização. O objetivo deste estudo foi investigar, por meio de avaliação funcional, o efeito da terapia a laser de baixa intensidade (660 nm) na regeneração do nervo isquiático após esmagamento. Foram utilizados 18 ratos (Wistar) submetidos à lesão do nervo isquiático divididos em dois grupos, controle e grupo laser, submetido ao tratamento a laser (AsGaAl, 660 nm, 10J/cm2, 30 mW e 0,06 cm²) por 21 dias no local da lesão. Para a avaliação funcional, foi aplicado o índice funcional do ciático (IFC) no pré-operatório e nos 7º, 14º e 21º dias de pós-operatório. Quando comparados o IFC dos grupos no 14o dia de pós-operatório, foi encontrada melhora significante no grupo laser em relação ao controle. Na amostra analisada e nos parâmetros utilizados, pôde-se constatar que a aplicação do laser foi eficaz na recuperação funcional precoce do nervo ciático esmagado.; Peripheral nerves, when injured, may originate important motor and sensitive disability. Studies have used several therapeutic resources in order to achieve early nervous regeneration...