Objetivo: Caracterizar as respostas do Mismatch Negativity (MMN) em crianças com limiares auditivos dentro dos padrões de normalidades e sem queixas auditivas. Métodos: Estudo do tipo transversal. Participaram desta pesquisa crianças de cinco a onze anos, sem queixas auditivas. Todos os participantes realizaram avaliação audiológica periférica com medidas de imitância acústica, audiometria tonal e audiometria vocal previamente à realização do MMN. Para a execução do procedimento eletrofisiológico, MMN, foi utilizado o equipamento Masbe ATC Plus da marca Contronic. Os eletrodos foram fixados nas posições Fpz (eletrodo ativo), M1 e M2 (eletrodos referência) e na fronte (eletrodo terra). A intensidade utilizada para evocar o potencial foi de 80 dBNA, o estímulo frequente utilizado foi de 1.000 Hz e o estímulo raro de 2.000 Hz. Os estímulos foram apresentados em ambas as orelhas de modo monoaural. As crianças realizaram a avaliação sentadas e foram condicionadas a assistirem a um vídeo sem som, no tablet, enquanto o procedimento era realizado. Resultados: Para o grupo feminino, a média das latências e amplitudes foi de 177,3 ms e 5,01 μV na orelha direita e de 182,4 ms e 5,39 μV na orelha esquerda. Quanto ao grupo masculino, a média das latências foi de 194,4 ms na orelha direita e 183,6 ms na orelha esquerda, com amplitude de 5,11 μV na orelha direita e 5,83 μV na orelha esquerda. Não houve diferença estatisticamente significante nos valores de latência e amplitude entre orelhas (p=0,867 e p=0,178), idade (p>0,20) e sexo dos participantes (p>0,05). Conclusão: Os valores encontrados nas latências e amplitudes do potencial MMN são semelhantes aos observados na literatura científica compulsada, em crianças com desenvolvimento típico e sem queixas auditivas. / Aim: To characterize the answers of Mismatch Negativity (MMN) in children with hearing thresholds within the normality patterns and without auditory complaints. Methods: Transversal type study. Children between 5 and 11 years old without auditory complaints have participated in this research. All the participants have done peripheral audiological evaluation with acoustic immittance measures, tonal audiometry and vocal audiometry previously to MMN execution. To perform the electrophysiological procedure, MMN, it was used Masbe ATC Plus equipment from Contronic brand. The electrodes were fixed in Fpz (active electrode), M1 and M2 (reference electrodes) and front (earth electrode) positions. The intensity used to evoke the potential was 80 dBNA, the frequent stimulus used was 1.000 Hz and the rare stimulus was 2.000 Hz. The stimuli were presented in both ears monoaurally. Children performed the assessment sat and they were conditioned to watch a video without sound, on a tablet computer, while the procedure was performed. Results: For the female group, the average of the latencies and amplitudes was 177,3 ms and 5,01 μV for the right ear and 182,4 ms and 5,39 μV for the left ear. Regarding the male group, the average of latencies was 194,4 ms for the right ear and 183,6 ms for the left ear, with an amplitude of 5,11 μV for the right ear and 5,83 μV for the left ear. There was no significant statistically difference for the values of latency and amplitude among ears (p=0,867 and p=0,178), age (p>0,20) and gender of the participants (p>0,05). Conclusion: The values found in the latencies and amplitudes of MMN potential are similar to those observed in the scientific literature examined, in children with typical development and without auditory complaints.

Neste trabalho estudamos uma nova classe de superpotenciais em mecânica quântica supersimétrica, os quais denominamos de modulares, por serem funções do módulo da coordenada x. O superpotencial de partida proposto é da forma x |x|. Esta ideia permite tornar solúvel exatamente, a energia zero, um incontável número de potenciais gerados por estas funções no âmbito da mecânica quântica supersimétrica. Exploramos algumas aplicações para estes superpotenciais, com ênfase para uma representação da molécula de amônia supersimétrica e, em particular, mostramos que um sistema muito estudado na literatura, gerado pelo superpotencial x 1/x, pode ser resolvido mais facilmente recorrendo-se à representação modular. Procuramos estudar as soluções exatas ou aproximadas - do espectro de energias dos Hamiltonianos parceiros supersimétricos utilizando metodologias adequadas ao respectivo caso, incluindo-se o conhecido potencial x4, sendo que o método variacional de coeficientes de funções foi o que melhor se adaptou ao estudo. Este método, pouco utilizado até o momento na literatura, permitiu não apenas resolver com excelente aproximação os primeiros níveis do sistema em estudo, como também comprovou a supersimetria do sistema modular. Mostramos também que em sistemas quânticos supersimétricos, a equação de Schroedinger pode ser colocada na forma da equação de Sturm-Liouville e apresentar soluções de polinômios ortogonais, sendo que a função-peso de tais polinômios é gerada pelo superpotencial. Uma breve abordagem da simetria PT envolvendo diretamente o potencial por nós proposto também foi investigada, e mostramos que o sistema é equivalente a um Hamiltoniano não Hermitiano com potencial V(z) = (z4). / In this work we study a new class of superpotentials in supersymmetric quantum mechanics, which we call modular because of their dependence on the modulus of the x coordinate. The starting superpotential is of the form x |x|. This idea helps make exactly solvable, at zero energy, several potentials generated by these functions in the context of supersymmetric quantum mechanics. We explore some applications for these superpotenciais, with emphasis on a representation of the supersymmetric ammonia molecule and, in particular, we show that a system generated by the superpotential x-1/x, widely studied in the literature, can be solved more easily making use to the modular representation. We also seek for spectral solutions exact or approximated - of the partners Hamiltonians based on the exact ground state wave function of zero energy including the conventional x4 potential. The use of the variational method of functions coefficients. These methods, rarely used to date in the literature, allowed not only solve with excellent approximation the first levels of the system under study, but also proved the supersymmetry of the modular system. The results were compared with others found in the literature. We also show that for supersymmetric quantum systems, the Schroedinger equation can be put in a form of the Sturm-Liouville equation, and so, orthogonal polynomials solutions can be find through a weight-function generated by the superpotential. A brief overview of the PTsymmetry of the system directly involving a modular model proposed was also investigated, and we show that this system is equivalent to the non-Hermitian Hamiltonian one with potential V (z) = z4.

Reading requires the successful recruitment and coordination of brain networks to translate visual symbols into phonemes, which are then sequenced to match speech sounds and matched onto semantic representations. Although phonemic awareness is understood to be a core deficit associated with reading disability, neuroimaging has demonstrated an association between poor reading and disruption to various interrelated areas in the brain. This includes one of the major visual pathways, the magnocellular pathway, which contributes to the dorsal pathway in the brain and the processing of motion. For at least two decades, researchers have observed differences in motion processing, supported by the magnocellular pathway, between individuals with and without dyslexia (Eden et al., 1996; Gori et al., 2016; Livingstone et al., 1991; Wilmer, 2004). Further, psychometric studies report an association between reading ability and dorsal stream sensitivity in adults and in children before and after learning to read (Boets et al., 2011; Kevan & Pammer, 2009). Studies of the development of the major visual pathways have suggested that the magnocellular pathway follows a protracted course of development, which raises the possibility that it is vulnerable to pathological change during development and also has the potential for greater plasticity (Armstrong et al., 2002; Stevens & Neville, 2006). To explore the potential differences in early-stage visual processing, this dissertation study investigated whether neurophysiological measures, as indexed by event-related potentials (ERP), may differ between adults with and without dyslexia to stimuli tailored to evoke a response from each of two major visual pathways: magnocellular and parvocellular. The P1 component was elicited in response to motion stimuli designed to probe magnocellular pathways, and the N1 component was elicited in response to color stimuli designed for parvocellular processing. Group comparisons revealed statistically significant group differences in P1 amplitude for the motion/magnocellular condition, but no differences were found for N1 ERP measures for the parvocellular/color condition. Moderate to strong correlations between P1 measures in response to the magnocellular/motion condition were observed in relation to specific behavioral assessments: nonverbal reasoning and memory, orthographic choice, the word identification subtest from the Woodcock Reading Mastery Test (3rd edition: WRMT-III, Woodcock, 2011), and the sight word efficiency subtest from the Test of Word Reading Efficiency (2nd edition: TOWRE-2, Wagner, Torgesen, & Rashotte, 2011). These results are indicative of an early-stage visual processing disruption in individuals with dyslexia observable at the level of the brain. Due to the compounding impact of even small disruptions of sensory and cognitive processing on learning, refining our knowledge of the underlying neural mechanisms of reading may permit earlier identification and potentially more focused interventions that could yield better outcomes for struggling readers. Additionally, the association of those differences with measures of word decoding will inform further research into the underlying neural mechanisms that may contribute to dyslexia and skilled reading.

In my Event-Related Potential studies, these two factors are analyzed collectively. Two dichotic listening experiments, one word phonological priming experiment, and one sentence semantic violation experiment are conducted. The results indicate that the linguistic role (e.g. semantics) causes the tone processing toward the left side, whereas the physical property causes the tone processing toward the right side. / In this dissertation, I discuss the effects of the linguistic role and the physical property on the hemispheric specialization (lateralization) of the lexical tones. In the previous studies of lateralization, there are two contradictory hypotheses. One emphasizes the linguistic role and predicts a left lateralization of tone perception, while the other emphasizes the physical property and predicts a right lateralization of tone perception. Both hypotheses have their supporting evidence. / No previous tone lateralization studies have analyzed the underlying factors. Following the philosophy that language is built upon multiple cognitive functions, I further examine the effects of semantic memory and pitch processing on the lateralization of tones in various language tasks. My findings help bridge the previous theoretical discrepancies and unify the conflicting experimental results regarding tone lateralization. / Shuai, Lan / Adviser: William S-Y. Wang. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 144-153). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

What are the effects of non-balanced bilingualism on cognitive performance? And how do proficient, non-native speakers acquire and use lexical, syntactic and semantic information during sentence processing? Whilst there is growing research on these topics, there is no firm consensus on how to answer these questions. In the literature on cognitive effects of bilingualism, this lack of consensus has even resulted in radically opposing views and a heated debate. In this thesis, I seek to provide a balanced treatment of the literature and to address the above-mentioned questions by employing behavioral and neurophysiological paradigms. First, using a structural priming paradigm, I examine how proficient, non-native speakers of different native language backgrounds (Romance and Germanic) acquire lexically-specific syntactic restrictions of non-alternating verbs in English. Results from these experiments suggest that, although non-native speakers partially acquire lexically-specific syntactic restrictions, their knowledge is not native-like. Moreover, transfer from the first language does not seem to play a role in the acquisition of the relevant restrictions. Second, using Event-Related Potentials (ERPs) I examine whether proficient non-native Spanish-English speakers draw on different forms of semantic information such as relatedness and animacy incrementally during sentence comprehension. Results of these experiments suggest that, while relatedness facilitates processing (indexed by N400s) in both native and non-native speakers, effects of animacy are smaller in non-native speakers, relative to native speakers. Third, I employ a series of auditory attentional tasks and measures of lexical access and verbal fluency to assess cognitive functions in non-balanced bilinguals with different levels of language proficiency. Results show a bilingual advantage in inhibitory control and a non-significant trend towards bilingual better performance in attentional switching, and the groups exhibit similar performance on verbal fluency. Results of all the studies are discussed in the context of the existing literature on cognitive performance in bilinguals and accounts of language processing in native and non-native speakers and suggestions for future research are provided.

Recent research has shown that distinct event-related potential (ERP) signatures are associated with switching between languages compared to switching between dialects or registers (e.g., Khamis-Dakwar & Froud, 2007; Moreno, Federmeier & Kutas, 2002). The current investigation builds on these findings to examine whether contrastive and non-contrastive morphosyntactic features in English elicit differing neural responses in bidialectal speakers of African American English (AAE) and Mainstream American English (MAE), compared to monodialectal speakers of MAE. Event-related potentials (ERPs) and behavioral responses (response types and reaction time) to grammaticality judgments targeting a contrasting morphosyntactic feature between MAE and AAE are presented as evidence of dual-language representation in bidialectal speakers. Results from 30 participants (15 monodialectal; 15 bidialectal) support the notion that bidialectal populations demonstrate distinct neurophysiological profiles from monolingual groups as indicated by a significantly greater P600 amplitude from 500ms – 800ms time window in the monodialectal group, when listening to sentences containing contrasting features. Such evidence can support the development of linguistically informed educational curriculums and clinical approaches from speech-language pathologists, by elucidating the differing underlying processes of language between monodialectal and bidialectal speakers of American English.

Os potenciais evocados auditivos de longa latência fornecem dados objetivos sobre a funcionalidade das estruturas corticais auditivas. O objetivo do presente estudo foi caracterizar a maturação do sistema auditivo central em crianças com audição normal por meio destes potenciais. Foram avaliados 56 indivíduos de ambos os sexos, com audição dentro dos padrões de normalidade, comprovada por audiometria e imitanciometria, sendo 46 crianças, de três a 12 anos, e 10 adultos jovens, os quais foram incluídos a título de comparação com a casuística infantil. O equipamento utilizado disponibilizava dois canais de registro, sendo um destinado à captação dos potenciais evocados auditivos de longa latência e outro, ao registro do artefato gerado pelo movimento ocular, visando ao seu controle. Os potenciais foram registrados com os indivíduos em estado de alerta, assistindo a um vídeo mudo, por meio de eletrodos posicionados em Cz (ativo) e A2 (referência) e os movimentos oculares, por eletrodos em posição supra e infra-orbital esquerda; o eletrodo terra foi colocado em A1. Foram analisados os valores de latência e de amplitude dos componentes P1, N1 e P2, bem como a morfologia destes componentes de acordo com a idade. Para verificar a reprodutibilidade dos potenciais registrados, foi realizado um estudo duplo-cego com a introdução da análise de uma avaliadora experiente em Eletrofisiologia, a qual não mostrou diferenças estatisticamente significantes da análise feita pela autora da pesquisa. Como resultado, constatou-se, quanto à morfologia, melhora na definição dos componentes com o avanço da idade. Foi observada diminuição nos valores de latência dos componentes P1, N1 e P2 com o avanço da idade. Não foi observada variação nos valores de amplitude com o avanço da idade para os componentes N1 e P2, exceto para o componente P1, que teve sua amplitude diminuída. Não foi observada diferença estatisticamente significante entre os sexos. Pôde-se observar que o processo maturacional do sistema auditivo central acontece de maneira gradativa, sendo as maiores modificações observadas ao se comparar crianças e adultos. / The long latency auditory evoked potentials provide objective data on the function of hearing cortical structures. This study aims at characterizing the maturation of the central hearing system, in normally hearing children, through these potentials. Fifty-six subjects from both genders, with hearing within normality patterns, verified by means of audiometry and imitanciometry, were evaluated, being 46 children in the age range 3-12, and 10 young adults, who were included for comparison with the infantile sample. The equipment utilized had two recording channels: one to catch the long latency auditory evoked potentials, and the other, to record the artifact generated by ocular movement, aiming at its control. The potentials were recorded with subjects alert, while watching a mute video, through electrodes positioned in Cz (active) and A2 (reference), and the ocular movements, through electrodes in left supra and infra-orbital position and the ground electrode was placed in A1. Values of latency and of amplitude for components P1, N1 and P2, as well as the morphology of these components, according to age, were analyzed. In order to verify the reproducibility of the recorded potentials, a double blind study was carried out, by introducing the analysis of an experienced Electrophysiology evaluator, whose analysis did not show statistically significant differences, as compared to that performed by the author of the research. Thus, as to morphology, improvement in the definition of components was seen, as age increased. A decrease in latency values of components P1, N1 and P2 was observed, as age advanced. No variation was verified in amplitude values, as age increased, for components N1 and P2, except for component P1, whose amplitude was diminished. No statistically significant difference was seen between genders. It was verified that the maturational process of the central hearing system takes place in a gradual fashion, being the greatest modifications seen, when comparing children and adults.

Ho, Pui Kwan. / "November 2010." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 68-75). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / List of figures --- p.vi / List of tables --- p.viii / Abbreviations --- p.ix / Chapter Chapter 1. --- Introduction / Chapter 1.1. --- Overview --- p.1 / Chapter 1.2. --- Thesis organization --- p.6 / Chapter Chapter 2. --- Background / Chapter 2.1. --- Brain structure and its functional organization --- p.8 / Chapter 2.2. --- Introduction to lateralization investigation techniques --- p.13 / Chapter 2.2.1. --- Lesion studies and Wada test --- p.13 / Chapter 2.2.2. --- Dichotic listening --- p.14 / Chapter 2.2.3. --- Functional Magnetic Resonance Imaging (fMRI) --- p.15 / Chapter 2.2.4. --- Electroencephalography(EEG) & event-related potential(ERP) --- p.16 / Chapter 2.2.5. --- Other brain imaging techniques --- p.20 / Chapter 2.2.6. --- Comparing different brain-imaging techniques in this study --- p.20 / Chapter 2.3. --- Literature review and the current work --- p.21 / Chapter 2.3.1 --- "The functional and acoustic ""dichotomy""" --- p.22 / Chapter 2.3.2. --- Studies on lateralization of tones without linguistic context --- p.25 / Chapter 2.3.3. --- Studies on lexical tone lateralization --- p.27 / Chapter 2.3.4. --- The current work ´ؤ aim and hypothesis --- p.34 / Chapter Chapter 3. --- Methodology / Chapter 3.1. --- Stimuli --- p.36 / Chapter 3.2. --- Subject --- p.41 / Chapter 3.3. --- Task design --- p.41 / Chapter 3.4. --- ERP recording and data processing --- p.44 / Chapter Chapter 4. --- Results and discussions / Chapter 4.1. --- Behavioural data analysis --- p.46 / Chapter 4.2. --- ERP data analysis --- p.48 / Chapter 4.3. --- Discussions --- p.52 / Chapter Chapter 5. --- Further discussions / Chapter 5.1. --- Is lateralization of lexical tone language-specific? --- p.57 / Chapter 5.2. --- Toward a model of speech lateralization --- p.59 / Chapter 5.3. --- An implication on tone feature systems --- p.60 / Chapter Chapter 6. --- Conclusion / Chapter 6.1. --- Conclusion --- p.65 / Chapter 6.2. --- Future work --- p.67 / References --- p.68 / Appendix / Chapter A.1. --- Edinburgh handedness test --- p.76 / Chapter A.2. --- Handedness scores --- p.77

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