Enhancing BOLD response in the auditory system by neurophysiologically tuned fMRI sequence

Auditory neuroscience has not tapped fMRI's full potential because of acoustic scanner noise emitted by the gradient switches of conventional echoplanar fMRI sequences. The scanner noise is pulsed, and auditory cortex is particularly sensitive to pulsed sounds. Current fMRI approaches to avoid stimulus-noise interactions are temporally inefficient. Since the sustained BOLD response to pulsed sounds decreases with repetition rate and becomes minimal with unpulsed sounds, we developed an fMRI sequence emitting continuous rather than pulsed gradient sound by implementing a novel quasi-continuous gradient switch pattern. Compared to conventional fMRI, continuous-sound fMRI reduced auditory cortex BOLD baseline and increased BOLD amplitude with graded sound stimuli, short sound events, and sounds as complex as orchestra music with preserved temporal resolution. Response in subcortical auditory nuclei was enhanced, but not the response to light in visual cortex. Finally, tonotopic mapping using continuous-sound fMRI demonstrates that enhanced functional signal-to-noise in BOLD response translates into improved spatial separability of specific sound representations.

ANALYSIS AND VISUALIZATION OF FLOW FIELDS USING INFORMATION-THEORETIC TECHNIQUES AND GRAPH-BASED REPRESENTATIONS

Three-dimensional flow visualization plays an essential role in many areas of science and engineering, such as aero- and hydro-dynamical systems which dominate various physical and natural phenomena. For popular methods such as the streamline visualization to be effective, they should capture the underlying flow features while facilitating user observation and understanding of the flow field in a clear manner. My research mainly focuses on the analysis and visualization of flow fields using various techniques, e.g. information-theoretic techniques and graph-based representations. Since the streamline visualization is a popular technique in flow field visualization, how to select good streamlines to capture flow patterns and how to pick good viewpoints to observe flow fields become critical. We treat streamline selection and viewpoint selection as symmetric problems and solve them simultaneously using the dual information channel [81]. To the best of my knowledge, this is the first attempt in flow visualization to combine these two selection problems in a unified approach. This work selects streamline in a view-independent manner and the selected streamlines will not change for all viewpoints. My another work [56] uses an information-theoretic approach to evaluate the importance of each streamline under various sample viewpoints and presents a solution for view-dependent streamline selection that guarantees coherent streamline update when the view changes gradually. When projecting 3D streamlines to 2D images for viewing, occlusion and clutter become inevitable. To address this challenge, we design FlowGraph [57, 58], a novel compound graph representation that organizes field line clusters and spatiotemporal regions hierarchically for occlusion-free and controllable visual exploration. We enable observation and exploration of the relationships among field line clusters, spatiotemporal regions and their interconnection in the transformed space. Most viewpoint selection methods only consider the external viewpoints outside of the flow field. This will not convey a clear observation when the flow field is clutter on the boundary side. Therefore, we propose a new way to explore flow fields by selecting several internal viewpoints around the flow features inside of the flow field and then generating a B-Spline curve path traversing these viewpoints to provide users with closeup views of the flow field for detailed observation of hidden or occluded internal flow features [54]. This work is also extended to deal with unsteady flow fields. Besides flow field visualization, some other topics relevant to visualization also attract my attention. In iGraph [31], we leverage a distributed system along with a tiled display wall to provide users with high-resolution visual analytics of big image and text collections in real time. Developing pedagogical visualization tools forms my other research focus. Since most cryptography algorithms use sophisticated mathematics, it is difficult for beginners to understand both what the algorithm does and how the algorithm does that. Therefore, we develop a set of visualization tools to provide users with an intuitive way to learn and understand these algorithms.

3D Face Reconstruction from 2D Pictures: First Results of a Web-Based Computer Aided System for Aesthetic Procedures

The human face is a vital component of our identity and many people undergo medical aesthetics procedures in order to achieve an ideal or desired look. However, communication between physician and patient is fundamental to understand the patient’s wishes and to achieve the desired results. To date, most plastic surgeons rely on either “free hand” 2D drawings on picture printouts or computerized picture morphing. Alternatively, hardware dependent solutions allow facial shapes to be created and planned in 3D, but they are usually expensive or complex to handle. To offer a simple and hardware independent solution, we propose a web-based application that uses 3 standard 2D pictures to create a 3D representation of the patient’s face on which facial aesthetic procedures such as filling, skin clearing or rejuvenation, and rhinoplasty are planned in 3D. The proposed application couples a set of well-established methods together in a novel manner to optimize 3D reconstructions for clinical use. Face reconstructions performed with the application were evaluated by two plastic surgeons and also compared to ground truth data. Results showed the application can provide accurate 3D face representations to be used in clinics (within an average of 2 mm error) in less than 5 min.

Sensory and conceptual representations in memory: Motor images which cannot be imaged

The paper argues for a distinction between sensory-and conceptual-information storage in the human information-processing system. Conceptual information is characterized as meaningful and symbolic, while sensory information may exist in modality-bound form. Furthermore, it is assumed that sensory information does not contribute to conscious remembering and can be used only in data-driven process reptitions, which can be accompanied by a kind of vague or intuitive feeling. Accordingly, pure top-down and willingly controlled processing, such as free recall, should not have any access to sensory data. Empirical results from different research areas and from two experiments conducted by the authors are presented in this article to support these theoretical distinctions. The experiments were designed to separate a sensory-motor and a conceptual component in memory for two-digit numbers and two-letter items, when parts of the numbers or items were imaged or drawn on a tablet. The results of free recall and recognition are discussed in a theoretical framework which distinguishes sensory and conceptual information in memory.

Towards workflow ecosystems through standard representations

Workflows are increasingly used to manage and share scientific computations and methods. Workflow tools can be used to design, validate, execute and visualize scientific workflows and their execution results. Other tools manage workflow libraries or mine their contents. There has been a lot of recent work on workflow system integration as well as common workflow interlinguas, but the interoperability among workflow systems remains a challenge. Ideally, these tools would form a workflow ecosystem such that it should be possible to create a workflow with a tool, execute it with another, visualize it with another, and use yet another tool to mine a repository of such workflows or their executions. In this paper, we describe our approach to create a workflow ecosystem through the use of standard models for provenance (OPM and W3C PROV) and extensions (P-PLAN and OPMW) to represent workflows. The ecosystem integrates different workflow tools with diverse functions (workflow generation, execution, browsing, mining, and visualization) created by a variety of research groups. This is, to our knowledge, the first time that such a variety of workflow systems and functions are integrated.

Functional organization of the hippocampal memory system

In humans declarative or explicit memory is supported by the hippocampus and related structures of the medial temporal lobe working in concert with the cerebral cortex. This paper reviews our progress in developing an animal model for studies of cortical–hippocampal interactions in memory processing. Our findings support the view that the cortex maintains various forms of memory representation and that hippocampal structures extend the persistence and mediate the organization of these codings. Specifically, the parahippocampal region, through direct and reciprocal interconnections with the cortex, is sufficient to support the convergence and extended persistence of cortical codings. The hippocampus itself is critical to the organization cortical representations in terms of relationships among items in memory and in the flexible memory expression that is the hallmark of declarative memory.

Numerical representations in primates.

Research has demonstrated that human infants and nonhuman primates have a rudimentary numerical system that enables them to count objects or events. More recently, however, studies using a preferential looking paradigm have suggested that preverbal human infants are capable of simple arithmetical operations, such as adding and subtracting a small number of visually presented objects. These findings implicate a relatively sophisticated representational system in the absence of language. To explore the evolutionary origins of this capacity, we present data from an experiment with wild rhesus monkeys (Macaca mulatta) that methodologically mirrors those conducted on human infants. Results suggest that rhesus monkeys detect additive and subtractive changes in the number of objects present in their visual field. Given the methodological and empirical similarities, it appears that nonhuman primates such as rhesus monkeys may also have access to arithmetical representations, although alternative explanations must be considered for both primate species.

Everything in di Dark Muss Come to Light: A Postcolonial Investigation of the Practice of Extra Lessons at the Secondary Level in Jamaica's Education System

Despite the vast research examining the evolution of Caribbean education systems, little is chronologically tied to the postcolonial theoretical perspectives of specific island-state systems, such as the Jamaican education system and its relationship with the underground shadow education system. This dissertation study sought to address the gaps in the literature by critically positioning postcolonial theories in education to examine the macro- and micro-level impacts of extra lessons on secondary education in Jamaica. The following postcolonial theoretical (PCT) tenets in education were contextualized from a review of the literature: (a) PCT in education uses colonial discourse analysis to critically deconstruct and decolonize imperialistic and colonial representations of knowledge throughout history; (b) PCT in education uses an anti-colonial discursive framework to re-position indigenous knowledge in schools, colleges, and universities to challenge hegemonic knowledge; (c) PCT in education involves the "unlearning" of dominant, normative ideologies, the use of self-reflexivity, and deconstruction; and (d) PCT in education calls for critical pedagogical approaches that reject the banking concept of education and introduces inclusive pedagogy to facilitate "the passage from naïve to critical transitivity" (Freire, 1973, p. 32). Specifically, using a transformative mixed-methods design, grounded and informed by a postcolonial theoretical lens, I quantitatively uncovered and then qualitatively highlighted how if at all extra lessons can improve educational outcomes for students at the secondary level in Jamaica. Accordingly, the quantitative data was used to test the hypotheses that the practice of extra lessons in schools is related to student academic achievement and the practice of critical-inclusive pedagogy in extra lessons is related to academic achievement. The two-level hierarchical linear model analysis revealed that hours spent in extra lessons, average household monthly income, and critical-inclusive pedagogical tents were the best predictors for academic achievement. Alternatively, the holistic multi-case study explored how extra-lessons produces increased academic achievement. The data revealed new ways of knowledge construction and critical pedagogical approaches to galvanize systemic change in secondary education. Furthermore, the data showed that extra lessons can improve educational outcomes for students at the secondary level if the conditions for learning are met. This study sets the stage for new forms of knowledge construction and implications for policy change.

Bi-sensory, striped representations: comparative insights from owl and platypus

Bi-sensory striped arrays are described in owl and platypus that share some similarities with the other variant of bi-sensory striped array found in primate and carnivore striate cortex: ocular dominance columns. Like ocular dominance columns, the owl and platypus striped systems each involve two different topographic arrays that are cut into parallel stripes, and interdigitated, so that higher-order neurons can integrate across both arrays. Unlike ocular dominance stripes, which have a separate array for each eye, the striped array in the middle third of the owl tectum has a separate array for each cerebral hemisphere. Binocular neurons send outputs from both hemispheres to the striped array where they are segregated into parallel stripes according to hemisphere of origin. In platypus primary somatosensory cortex (SI), the two arrays of interdigitated stripes are derived from separate sensory systems in the bill, 40,000 electroreceptors and 60,000 mechanoreceptors. The stripes in platypus SI cortex produce bimodal electrosensory-mechanosensory neurons with specificity for the time-of-arrival difference between the two systems. This thunder-and-lightning system would allow the platypus to estimate the distance of the prey using time disparities generated at the bill between the earlier electrical wave and the later mechanical wave caused by the motion of benthic prey. The functional significance of parallel, striped arrays is not clear, even for the highly-studied ocular dominance system, but a general strategy is proposed here that is based on the detection of temporal disparities between the two arrays that can be used to estimate distance. (C) 2004 Elsevier Ltd. All rights reserved.

Gaussian phase-space representations for fermions

We introduce a positive phase-space representation for fermions, using the most general possible multimode Gaussian operator basis. The representation generalizes previous bosonic quantum phase-space methods to Fermi systems. We derive equivalences between quantum and stochastic moments, as well as operator correspondences that map quantum operator evolution onto stochastic processes in phase space. The representation thus enables first-principles quantum dynamical or equilibrium calculations in many-body Fermi systems. Potential applications are to strongly interacting and correlated Fermi gases, including coherent behavior in open systems and nanostructures described by master equations. Examples of an ideal gas and the Hubbard model are given, as well as a generic open system, in order to illustrate these ideas.

Classic identity negative priming involves accessing semantic representations in the left anterior temporal cortex

Classic identity negative priming (NP) refers to the finding that when an object is ignored, subsequent naming responses to it are slower than when it has not been previously ignored (Tipper, S.P., 1985. The negative priming effect: inhibitory priming by ignored objects. Q. J. Exp. Psychol. 37A, 571-590). It is unclear whether this phenomenon arises due to the involvement of abstract semantic representations that the ignored object accesses automatically. Contemporary connectionist models propose a key role for the anterior temporal cortex in the representation of abstract semantic knowledge (e.g., McClelland, J.L., Rogers, T.T., 2003. The parallel distributed processing approach to semantic cognition. Nat. Rev. Neurosci. 4, 310-322), suggesting that this region should be involved during performance of the classic identity NP task if it involves semantic access. Using high-field (4 T) event-related functional magnetic resonance imaging, we observed increased BOLD responses in the left anterolateral temporal cortex including the temporal pole that was directly related to the magnitude of each individual's NP effect, supporting a semantic locus. Additional signal increases were observed in the supplementary eye fields (SEF) and left inferior parietal lobule (IPL). (c) 2006 Elsevier Inc. All rights reserved.

O PROCESSO EDUCACIONAL DA CULTURA INDÍGENA TICUNA NA REGIÃO DO ALTO SOLIMÕES

Esse trabalho busca analisar o sistema educacional na tribo Ticuna, localizada na região do Alto Solimões, estado do Amazonas, onde estou há 21 anos em contato permanente com os índios Ticuna. Com o passar dos anos tenho observado que a cada dia, e de forma mais intensa, a manutenção de sua cultura vem sofrendo com o processo de influência da cultura não índia. Nesse trabalho realiza-se um levantamento histórico referente à possível existência de duas correntes educacionais entre os professores Ticuna. Uma considera importante um ensino bilíngue, o estudo dos mitos e costumes para preservação da cultura; a outra acredita que é inócuo estudar os mitos e outros aspectos culturais, que podem ser apreendidos no dia a dia, defendem que os índios precisam de uma educação igual a dos não indígenas, para competir no mercado em condições de igualdade. Inicialmente propõe-se uma busca histórica sobre o processo educacional relacionado à cultura Ticuna fora da escola, procurando verificar as relações entre o que é transmitido pela escola e o que se evidencia no cotidiano Ticuna. Em seguida, realiza-se uma análise de como se processa a educação implantada no meio Ticuna sob o título Educação Indígena . Destacam-se os fatores que influenciaram a fundação da escola, sua localização e aspectos relacionados ao meio físico, econômico, social e cultural, bem como, o ambiente humano e de aprendizagem, dados esses que subsidiam o objetivo proposto para este trabalho. Procura-se verificar se a educação desenvolvida na escola indígena cumpre o papel de estar constantemente buscando alternativas para uma educação que seja apropriada à sobrevivência da cultura Ticuna, uma educação adequada à realidade cultural. A pesquisa baseia-se em levantamento de dados através de documentos, como também em entrevistas com lideranças, professores e idosos da Tribo Ticuna; também na observação direta, com anotações feitas em caderno de campo. O processo de assimilação e influência da cultura não índia predomina na região do Alto Solimões e tem esmagado a cultura Ticuna, fazendo com que muitos já não queiram mais pescar, caçar ou viver como produtores ou coletores. É necessário buscar alternativas educacionais para a escola indígena Ticuna, em uma educação que seja apropriada para a sobrevivência de sua cultura e ao mesmo tempo minimize o preconceito enfrentado por esse povo. As lideranças e professores Ticuna esperam que a escola ajude na preservação e valorização de sua cultura. O prejuízo causado à educação cultural dos índios Ticuna é grande, a maioria dos jovens e crianças não são conhecedores dos significados dos rituais religiosos, mitos, lendas e crenças. Muitas vezes sabem até realizar o ritual, mas parece mais uma imitação de gestos, que se desvincula do seu real sentido. Espera-se que ao final dessa pesquisa sejamos capazes de utilizar o material desenvolvido para reflexão e que ela talvez possa servir como ponto de partida para os professores Ticuna na elaboração de diretrizes e desenvolvimento de um novo paradigma educacional que valorize mais a cultura.

REPRESENTAÇÕES SOCIAIS DOS ALUNOS DO PROGRAMA ESPECIAL DE FORMAÇÃO PEDAGÓGICA: UM ESTUDO SOBRE A FORMAÇÃO DOCENTE DE PROFESSORES, QUE JÁ SÃO PROFESSORES

O objetivo desta pesquisa é investigar o Programa Especial de Formação Pedagógica (PEFP), na perspectiva das representações sociais. Foram convidados a participar da pesquisa 463 (quatrocentos e sessenta e três) alunos, integrantes de cinco turmas do curso, sendo que 102 (cento e dois) alunos aceitaram e responderam voluntariamente ao questionário colocado no ambiente virtual de aprendizagem. Em seguida, foram selecionados entre os alunos respondentes, aqueles que já exerciam a docência. Esses professores foram convidados a participar de uma entrevista sobre sua formação docente, por meio do programa especial e 9 (nove) professores aceitaram. Também foram entrevistados 4 (quatro) diretores de escolas e supervisores de ensino que atuam ou atuaram na região metropolitana de Santos. A investigação se completou com a análise da legislação educacional e mandados judiciais referentes ao Programa Especial de Formação Pedagógica. Os dados obtidos foram analisados pelo software ALCESTE e por meio de Análise de Conteúdo, numa metodologia de pesquisa qualitativa. Os resultados apontaram a seguinte representação social: ser professor é ter formação pedagógica, formação profissional e formação acadêmica, por meio de uma licenciatura. Esta representação quanto à formação docente converge para a themata: ser professor é ser licenciado. A díade licenciado/não licenciado enuncia uma tensão existente no centro da representação identificada. Alunos e egressos do curso manifestaram insegurança sobre a legitimidade da licenciatura obtida por meio da complementação pedagógica e, consequentemente, sobre sua inserção profissional no sistema educacional. Entretanto, entrevistas feitas com supervisores de ensino e diretores de escola mostram o outro lado da formação pedagógica, por meio do PEFP. Os relatos dos diretores e supervisores de ensino apontam para a legitimação do curso e para o envolvimento profissional destes professores, nas escolas onde atuam.

TRADIÇÃO & INOVAÇÃO COMPETÊNCIAS TECNOLÓGICAS NECESSÁRIAS À PRÁTICA EDUCACIONAL

No presente trabalho realizamos uma análise sobre os novos paradigmas educacionais diante do fenômeno da expansão das tecnologias, as recomendações oficiais sobre a incorporação da tecnologia no contexto educacional e nas práticas docentes. Teve como objetivos pesquisar sobre as discussões acerca das contribuições da tecnologia no contexto educacional; analisar as competências necessárias para uma ação docente significativa utilizando as ferramentas que a tecnologia educacional disponibiliza para o professor; identificar como as inovações tecnológicas podem agregar valores às ações pedagógicas já existentes e suas múltiplas possibilidades de enriquecer a prática docente; analisar as razões pelas quais professores não conseguem agregar em sua rotina pedagógica a tecnologia. Realizamos uma pesquisa de campo que teve como sujeitos cinco professores do Fundamental 1ª fase, de Instituições Públicas(s) e Privadas(s) da cidade de Juiz de Fora/MG, atuantes na sala de aula. Para a coleta de dados aplicamos um questionário para a identificação do perfil dos sujeitos e entrevistas de aprofundamento. Para a análise dos dados das entrevistas utilizamos a metodologia de análise de conteúdo , proposta por Bardin (1979) e Franco (2003). Os resultados obtidos apontam para a necessidade de mudança no sistema educacional, um repensar da formação docente, pois hoje é fundamental que tenhamos professores capazes de incorporarem as tecnologias na prática cotidiana.

Recursive self-organizing map as a contractive iterative function system

Recently, there has been a considerable research activity in extending topographic maps of vectorial data to more general data structures, such as sequences or trees. However, the representational capabilities and internal representations of the models are not well understood. We rigorously analyze a generalization of the Self-Organizing Map (SOM) for processing sequential data, Recursive SOM (RecSOM [1]), as a non-autonomous dynamical system consisting off a set of fixed input maps. We show that contractive fixed input maps are likely to produce Markovian organizations of receptive fields o the RecSOM map. We derive bounds on parameter $\beta$ (weighting the importance of importing past information when processing sequences) under which contractiveness of the fixed input maps is guaranteed.