Plusieurs études ont montré que les maladies cardiovasculaires constituent un risque majeur de développement du trouble dépressif chez l’homme. Plus précisément, à la suite d’un infarctus du myocarde, 15 à 30 % des patients développent une dépression majeure dans les 6 à 8 mois suivant l’évènement cardiaque. Dans un modèle d’infarctus du myocarde chez le rat, développé dans notre laboratoire, nous avons noté la présence de comportements compatibles avec une dépression, deux semaines après l’infarctus. Nous avons également détecté des cellules apoptotiques dans le système limbique dès les premières minutes de reperfusion, nombre qui atteint son apogée à 3 jours de reperfusion. Nous avions émis l’hypothèse que l’apoptose que l’on observe dans le système limbique serait reliée à la réponse inflammatoire induite par l’infarctus du myocarde. Les comportements reliés à de la dépression ont été prévenus par l’administration d’un inhibiteur de la synthèse des cytokines pro-inflammatoires, la pentoxifylline, le célécoxib, un inhibiteur de la cyclooxygenase-2, par des probiotiques ainsi que par différents antidépresseurs. Les résultats des deux premières études de cette thèse montrent que la desvenlafaxine, un Inhibiteur de la recapture de la sérotonine et noradrénaline (IRSN) prévient les comportements dépressifs tout en diminuant l’apoptose à 3 jours post-infarctus dans le système limbique. Les comportements similaires à ceux d’une dépression que présentent les rats deux semaines après l’évènement cardiaque sont encore présents à 4 mois post-infarctus, si aucun traitement n’est entrepris. De plus, ces animaux développent des troubles d’apprentissage que la desvenlafaxine peut prévenir, et ceci même si le traitement n’est présent que pendant les 2 premières semaines post-infarctus. Dans la troisième étude de cette thèse, nous avons voulu savoir si le nerf vague était impliqué dans les effets bénéfiques de deux probiotiques sur l’apoptose dans le système limbique après un infarctus du myocarde. Nos résultats ont démontré que les probiotiques réduisent l’apoptose dans le système limbique après un infarctus du myocarde, mais que cet effet est perdu en présence d’une vagotomie. Les résultats obtenus démontrent que l’infarctus du myocarde induit une mort par apoptose dans le système limbique de même que des comportements dépressifs et des problèmes d’apprentissage à long terme. Ces problèmes peuvent être diminués par un traitement à la desvenlafaxine, et ceci même si le traitement n’est présent que pour les deux premières semaines post-infarctus. Finalement, nous avons observé que les probiotiques avaient des effets bénéfiques sur l’apoptose dans le système limbique par un mécanisme impliquant le nerf vague. En conclusion, plusieurs interventions différentes sont efficaces pour limiter les conséquences de l’infarctus du myocarde sur le système limbique et un traitement court est efficace pour prévenir les problèmes à plus long terme. / Several studies have highlighted that disruption of the cardiovascular functions is a major risk of developing depressive disorder in humans. 15-30% of the general population develops major depression within 6 to 8 months after a myocardial infarction. To better understand the underlying mechanisms and identify therapeutic pathways, we use a rat model of post-myocardial infarction developed in our laboratory. We have observed in these animals an increased apoptosis in the limbic system, which starts in the first minutes following reperfusion and peaks 3 days post-reperfusion. As a result, a depression-like phenotype and learning impairments appear 2 weeks after the myocardial infarction, which will persist up to 4 months after the infarct. We hypothesize that the observed apoptosis and the resulting depressive-like behavior are mediated by the inflammatory response induced after myocardial infarction. Indeed, depression-like behavior is prevented by the administration of an inhibitor of the pro-inflammatory cytokines, (pentoxifillyne, celecoxib), as well as by probiotics. In this thesis, we show that desvenlafaxine, a serotonin and noradrenaline reuptake inhibitor (SNRI) prevents death by apoptosis in the limbic system. Desvenlafaxine also helps to improve the depressive-like behavior in these rats as well as the learning impairments, even if the treatment is administered during the first 2 weeks post-reperfusion. Finally, we have discovered that vagotomy prevents the probiotics effect over the apoptosis appearing after myocardial infarction, highlighting the importance of the vagus nerve in the beneficial effects of probiotics. In conclusion, several interventions are effective in limiting the consequences of myocardial infarction on the limbic system and also key to prevent the apparition of secondary psychological disorders.

Les élèves dyslexiques éprouvent de grandes difficultés à lire et à écrire. Leurs difficultés en production orthographique sont reconnues pour être persistantes. Elles peuvent être expliquées par un déficit des procédures phonologiques. Or, pour orthographier une langue alphabétique comme le français, il est indispensable de développer des connaissances phonologiques puisque l’entrée dans l’écrit repose en grande partie sur la mise en correspondance de la langue orale et de sa réalisation à l’écrit. En plus des connaissances phonologiques, le système orthographique du français exige du scripteur d’acquérir des connaissances visuo-orthographiques et morphologiques. Les recherches menées sur la compétence orthographique des élèves dyslexiques se rapportent majoritairement à l’anglais et sur la compétence en lecture. La présente étude a pour objectif général de décrire, dans une visée explicative, la compétence orthographique de 26 élèves dyslexiques québécois âgés de 9 à 13 ans. Les objectifs spécifiques sont de décrire les performances de ces élèves en contexte de productions libres et de les comparer à celles de 26 élèves normo-lecteurs de même âge chronologique (CA) et à celles de 29 normo-lecteurs plus jeunes mais de même niveau en lecture (CL). Pour ce faire, nous avons analysé les erreurs en prenant en compte les propriétés phonologiques, visuo-orthographiques et morphologiques des mots écrits. Les résultats indiquent que les élèves dyslexiques ont des performances inférieures à celles des CA, mais aussi, dans certains cas, à celles des CL. Les résultats sont discutés en fonction des connaissances que doivent développer les scripteurs dyslexiques et des pistes orthodidactiques à envisager. / Learning to spell is very difficult for dyslexic children. Their difficulties to spell are known to be persistent. It can be explained by a deficit in processing phonological information. However, in order to spell correctly in an alphabetic language as French, phonological knowledge is required, as spelling is based on the connections between oral and written language. In addition to phonological knowledge, the orthographical system of French demands from the speller to acquire visual-orthographic and morphological knowledge. The majority of studies aimed at describing dyslexic children’s spelling abilities refers to English and to reading. The general goal of this study is to describe the spelling performance, in an explanatory viewpoint, of 26 dyslexic children, French-Canadian and aged 9 to 12 years old. The specific goals are to describe the spelling performances of these pupils in context of free productions and to compare them to those of 26 normally achieving children matched on age (AC) and to those of 29 younger normally achieving children matched on reading-level (RC). To do so, errors were classified according to phonological, visuo-orthographic and morphological properties of French written words. The results indicate that the dyslexic pupils made performances lower than those of the CA, but sometimes also than those of the CL. The results are discussed according to the types of knowledge required to spell correctly in French and to special-education intervention avenues.

Le développement de la compétence orthographique est particulièrement difficile pour les dyslexiques. Orthographier en français implique la prise en compte de connaissances et de stratégies variées. Cette étude a pour objectifs de décrire l’utilisation des stratégies de production orthographiques de 32 élèves dyslexiques (ED) âgés de 9 à 12 ans ainsi que d’établir les liens entre les stratégies orthographiques et la compétence orthographique. Les élèves devaient orthographier 24 mots sous dictée et commenter, pour chaque mot, les stratégies employées. Les performances des ED ont été comparées à celles de 25 normo scripteurs de même âge chronologique (CA) et à celles de 24 normo scripteurs de même compétence écrite (CE). Les résultats indiquent que les stratégies phonologiques sont les plus utilisées par tous les groupes de participants. Si aucun type de stratégies n’est lié à la compétence orthographique des ED, la stratégie visuo-orthographique nous éclaire sur les résultats des CA et des CE. / The development of spelling skill is a very difficult task for students with dyslexia. Spelling in French involves the consideration of various knowledge and strategies. This study aims to describe the use of spelling strategies of 32 dyslexic students (ED) aged from 9 to 12 years and to establish the links between spelling strategies and spelling skill. Students had to spell 24 words under dictation and for each word, provide comments on the strategy employed. The performances of dyslexics were compared to 25 children of the same chronological age (CA) and to 24 children of the same writing skill (CE). The results show that phonological strategies are the most commonly used by all groups of participants. If no such strategy is related to the spelling skill of ED, visuo-orthographic strategy generally accounts the results of CA and CE.

This thesis I deal with the issue of specific learning disabilities among students at 1 primary school and mention possible solutions. Due to the research carried out by the probe in the practical part of the work focuses on the specific disorder, dysgraphia writing. The thesis contains not only theoretical knowledge that I had to study the issue but a practical part. The practical part of my research included a probe that focused on observations of two boys while working in educational and psychological counseling. The practical part, I would usefully complement the relevant case report.

Os professores inseridos no ensino fundamental precisam estar preparados para lidar com alunos que possuem dificuldade na aprendizagem da linguagem escrita, e, no entanto, é reduzido número de instituições que oferecem cursos para aprimorar esses conhecimentos em muitas áreas do país, havendo-se assim, uma grande necessidade de investimentos na formação continuada do professor, devido ao seu importante papel principalmente na fase inicial de alfabetização, identificando precocemente os Transtornos de Aprendizagem. Objetivo Geral: Elaborar um material educacional interativo para informar os professores de ensino fundamental, via auto-orientação, a distância, sobre os Transtornos de Aprendizagem, disponibilizado em CD-ROM. Objetivos Específicos: Realizar um levantamento sobre o conhecimento e interesses dos professores sobre o assunto; verificar a contribuição do material elaborado para a obtenção de competências esperadas e avaliar o CD-ROM quanto aos seus aspectos técnicos (apresentação, recursos de navegação, imagens, clareza do texto). Método: Um questionário foi idealizado e elaborado para focar o conhecimento dos professores, levantando-se os pontos relevantes em relação as suas dúvidas e interesses sobre o tema abordado. Este questionário foi submetido a 31 professoras do ensino fundamental, sendo que participaram 20 professoras da rede pública e 11 professoras da rede particular. Por meio das respostas fornecidas pelas professoras participantes, construiu-se o conteúdo teórico sobre o assunto, e uma equipe técnica foi contratada para confeccionar o CD-ROM. As competências esperadas e os aspectos técnicos do material interativo multimídia foram avaliados por duas professoras-chaves, por meio da aplicação de questionários específicos. Resultados: Os professores apresentaram diversas necessidades em seu repertório conceitual no que diz respeito aos Transtornos de Aprendizagem, e, no entanto, este fato demonstra a necessidade de abordar estes conceitos na formação continuada desses profissionais. O CD-ROM Principais transtornos relacionados ao aprendizado da Leitura e Escrita: Manual Eletrônico para Professores foi elaborado de acordo com as dúvidas, sugestões e curiosidades das professoras, possibilitando o uso do CD-ROM (sendo este um material interativo com recursos multimídia) na formação continuada dos professores do Ensino Fundamental. Os aspectos técnicos tiveram avaliação positiva. Conclusão: O material educacional desenvolvido atendeu aos objetivos propostos, e, desta forma, fornece ao professor as competências esperadas e, ainda, em perspectivas futuras, pode ser utilizado para a estruturação de fóruns, chats, cybertutor e blogs, para troca de experiências. / Teachers in elementary school must be prepared to deal with students who have difficulty in learning written language, while there are few institutions offering courses to improve this knowledge in many areas of the country, thus, there is a great need for investment in teachers continuing education, due their important role especially in early literacy, making early identification of learning disorders. General Objective: To develop an interactive educational material to inform elementary school teachers, through distance self-orientation, about the Learning Disorders, available on CD-ROM. Specific Objectives: To conduct a survey of knowledge and interests of teachers about the theme; to check the contribution of the prepared material for the acquirement of expected competences and evaluate the CD-ROM about the technical aspects (presentation, navigation features, images, clearly text). Method: A questionnaire was idealized and developed to focus the knowledge of teachers, raising the relevant points regarding their doubts and concerns about the topic. This questionnaire was submitted to 31 elementary school teachers, and participated 20 public school teachers and 11 private.school teachers. Through the answers provided by participating teachers, the theoretical content about the subject was constructed, and a technical team was contracted to produce the CD-ROM. The expected competences and the technical aspects of interactive multimedia material were evaluated by two key teachers, through the application of specific questionnaires. Results: The results showed that teachers have several needs in their conceptual repertoire regarding Learning Disorders, and yet, this fact demonstrates the need to address these concepts in teachers continuing education. The CD-ROM \"Main disorders related to learning of Reading and Writing: Electronic Manual for Teachers\" was prepared in accordance with questions, suggestions and curiosities of the teachers, enabling the use of CD-ROM (an interactive multimedia material) for the continuing education of elementary school teachers. The technical aspects obtained positive evaluation. Conclusion: The educational materials developed reached the proposed objectives, and thus, provides the expected competencies for the teacher, and also, on future prospects, can be used for structuring forums, chats, blogs and cybertutor, favoring experiences exchange.

Introdução: Pouco se conhece sobre Transtorno Específico de Aprendizagem (TEA), principalmente em países de baixa e média renda (PBMR) e muito menos em amostras representativas de escolas de cidades pequenas fora de grandes centros urbanos. Poucos estudos enfatizaram os novos critérios do DSM-5 para TEA. Investigamos a prevalência do Transtorno Específico de Aprendizagem de acordo com a nova classificação do DSM-5, suas comorbidades e correlatos em amostras escolares de alunos do 2º ao 6º ano que moram em cidades de tamanho médio de quatro regiões geográficas do Brasil (norte, nordeste, centro-oeste e sudeste). Métodos: O rendimento acadêmico foi medido pelo Teste de Desempenho Escolar. Os diagnósticos psiquiátricos foram avaliados pelo K-SADS-PL com informações obtidas do cuidador primário e o QI foi estimado por subtestes do WISC-III. Resultados: Um total de 1.618 crianças e adolescentes foram incluídas no estudo. As taxas de prevalência encontradas de Transtorno Específico de Aprendizagem foram: 7,6% para comprometimento global, 5,4% para comprometimento na escrita, 6,0% para comprometimento na área da aritmética, e 7,5% para comprometimento na leitura. Diferenças significativas foram detectadas nas taxas de prevalência entre as cidades (p < 0,001). O Transtorno de Déficit de Atenção e Hiperatividade (TDAH) foi o único transtorno mental comórbido com associação significativa com TEA com comprometimento global (8,2%; p=0,031). Transtornos de ansiedade, TDAH e o grupo Qualquer Transtorno Mental foram associados com TEA com comprometimento na aritmética (13,8% com p=0,008; 12,4% com p < 0,001; 25,6% com p < 0,001, respectivamente). Inúmeros correlatos sóciodemográficos (idade (p=0,018), cidade (p=0,004), status sócio-econômico (p=0,007), gênero (p=0,011), e QI (p < 0,001)) foram associados com Transtorno Específico de Aprendizagem com comprometimento global na amostra. Conclusões: A validação e normatização de instrumentos que avaliem o desempenho acadêmico é ainda um grande problema em inúmeros países, mas principalmente naqueles de baixa e média renda (PBMR). Como esperado, foi encontrado uma significativa heterogeneidade nas taxas de prevalência de TEA entre as diferentes regiões geográficas do Brasil, sendo esse um país com forte diversidade. TEA com comprometimento global e em aritmética foram significativamente associados com comorbidades psiquiátricas. Todos correlatos avaliados (idade, cidade, status sócioeconômico, gênero, e QI) foram significativamente associados com TEA com comprometimento global / Introduction: Little is known about Specific Learning Disorder (SLD) in Low and Middle Income Countries (LMICs), and even less from representative school samples in small size cities outside huge urban centers. Few studies addressed the new DSM-5 criteria for SLDs. We investigated the prevalence of DSM-5 SLDs, their comorbidities and correlates in school samples of students from the 2nd to 6th grades living in median cities from 4 different geographic regions in Brazil (north, northeast, central and southeast). Methods: A national test for academic performance (TDE) covering reading, writing and mathematical abilities was applied. Psychiatric diagnoses were assessed by the K-SADS-PL applied to the primary caregiver, and IQ was estimated by WISC-III subtests. Results: A total of 1,618 children and adolescents were included in the study. The following prevalence rates of SLDs were found: 7.6% for global impairment, 5.4% for writing, 6.0% for arithmetic and 7.5% for reading impairment. Significant differences were detected in prevalence rates among cities (p < 0.001). Attention-deficit/Hyperactivity Disorder (ADHD) was the only comorbidity significantly associated with SLD with global impairment (8.2%; p=0.031). Anxiety Disorders, ADHD and the group Any Mental Disorder (13.8% with p=0.008; 12.4% with p < 0.001; 25.6% with p < 0.001, respectively) were associated with SLD with arithmetic impairment. Several socio-demographic correlates (age (p=0.018), city (p=0.004), socioeconomic status (p=0.007), gender (p=0.011), and IQ (p < 0.001)) were significantly associated with SLD with global impairment in our sample. Conclusions: Careful validation and normatization of instruments to assess academic performance is a major problem in LMICs. As expected, we found a significant heterogeneity in prevalence rates of SLD according to geographic regions considering that Brazil is a country with a robust diversity. SLD with global and arithmetic impairment were significantly associated with psychiatric comorbidities. All correlates investigated (age, city, socioeconomic status, gender, and IQ) were significantly associated with SLD with global impairment

Os professores inseridos no ensino fundamental precisam estar preparados para lidar com alunos que possuem dificuldade na aprendizagem da linguagem escrita, e, no entanto, é reduzido número de instituições que oferecem cursos para aprimorar esses conhecimentos em muitas áreas do país, havendo-se assim, uma grande necessidade de investimentos na formação continuada do professor, devido ao seu importante papel principalmente na fase inicial de alfabetização, identificando precocemente os Transtornos de Aprendizagem. Objetivo Geral: Elaborar um material educacional interativo para informar os professores de ensino fundamental, via auto-orientação, a distância, sobre os Transtornos de Aprendizagem, disponibilizado em CD-ROM. Objetivos Específicos: Realizar um levantamento sobre o conhecimento e interesses dos professores sobre o assunto; verificar a contribuição do material elaborado para a obtenção de competências esperadas e avaliar o CD-ROM quanto aos seus aspectos técnicos (apresentação, recursos de navegação, imagens, clareza do texto). Método: Um questionário foi idealizado e elaborado para focar o conhecimento dos professores, levantando-se os pontos relevantes em relação as suas dúvidas e interesses sobre o tema abordado. Este questionário foi submetido a 31 professoras do ensino fundamental, sendo que participaram 20 professoras da rede pública e 11 professoras da rede particular. Por meio das respostas fornecidas pelas professoras participantes, construiu-se o conteúdo teórico sobre o assunto, e uma equipe técnica foi contratada para confeccionar o CD-ROM. As competências esperadas e os aspectos técnicos do material interativo multimídia foram avaliados por duas professoras-chaves, por meio da aplicação de questionários específicos. Resultados: Os professores apresentaram diversas necessidades em seu repertório conceitual no que diz respeito aos Transtornos de Aprendizagem, e, no entanto, este fato demonstra a necessidade de abordar estes conceitos na formação continuada desses profissionais. O CD-ROM Principais transtornos relacionados ao aprendizado da Leitura e Escrita: Manual Eletrônico para Professores foi elaborado de acordo com as dúvidas, sugestões e curiosidades das professoras, possibilitando o uso do CD-ROM (sendo este um material interativo com recursos multimídia) na formação continuada dos professores do Ensino Fundamental. Os aspectos técnicos tiveram avaliação positiva. Conclusão: O material educacional desenvolvido atendeu aos objetivos propostos, e, desta forma, fornece ao professor as competências esperadas e, ainda, em perspectivas futuras, pode ser utilizado para a estruturação de fóruns, chats, cybertutor e blogs, para troca de experiências. / Teachers in elementary school must be prepared to deal with students who have difficulty in learning written language, while there are few institutions offering courses to improve this knowledge in many areas of the country, thus, there is a great need for investment in teachers continuing education, due their important role especially in early literacy, making early identification of learning disorders. General Objective: To develop an interactive educational material to inform elementary school teachers, through distance self-orientation, about the Learning Disorders, available on CD-ROM. Specific Objectives: To conduct a survey of knowledge and interests of teachers about the theme; to check the contribution of the prepared material for the acquirement of expected competences and evaluate the CD-ROM about the technical aspects (presentation, navigation features, images, clearly text). Method: A questionnaire was idealized and developed to focus the knowledge of teachers, raising the relevant points regarding their doubts and concerns about the topic. This questionnaire was submitted to 31 elementary school teachers, and participated 20 public school teachers and 11 private.school teachers. Through the answers provided by participating teachers, the theoretical content about the subject was constructed, and a technical team was contracted to produce the CD-ROM. The expected competences and the technical aspects of interactive multimedia material were evaluated by two key teachers, through the application of specific questionnaires. Results: The results showed that teachers have several needs in their conceptual repertoire regarding Learning Disorders, and yet, this fact demonstrates the need to address these concepts in teachers continuing education. The CD-ROM \"Main disorders related to learning of Reading and Writing: Electronic Manual for Teachers\" was prepared in accordance with questions, suggestions and curiosities of the teachers, enabling the use of CD-ROM (an interactive multimedia material) for the continuing education of elementary school teachers. The technical aspects obtained positive evaluation. Conclusion: The educational materials developed reached the proposed objectives, and thus, provides the expected competencies for the teacher, and also, on future prospects, can be used for structuring forums, chats, blogs and cybertutor, favoring experiences exchange.

Objetivo. Avaliar a função aritmética em crianças com Transtorno do Déficit de Atenção / Hiperatividade (TDAH) e determinar se o tratamento com psicoestimulante afeta seu desempenho (braço clínico), além de verificar o padrão de ativação neural em um subgrupo desta amostra durante tarefas de cálculos aritméticos (braço neuroimagem). Métodos. Quarenta e duas crianças (de 9 a 12 anos) participaram do braço clínico: 20 com TDAH segundo os critérios do DSM-IV e 22 controles. Estas crianças foram classificados com ou sem dificuldades aritméticas com base em seu desempenho em três testes aritméticos utilizados no Brasil. Todos os participantes do braço clínico foram avaliados em dois momentos: tempo 1 e no tempo 2 quando as crianças com TDAH estavam em uso de metilfenidato (MTF) a uma dose de 0,3-0,5 mg/kg. Foi avaliado o desempenho global em aritmética e, especificamente, exploramos a subtração nos dois tempos. Foram também estudadas 10 crianças com TDAH (seis das quais participaram do braço clínico) que participaram com uso de metilfenidato e 10 crianças saudáveis (oito das quais participaram do braço clínico) que realizaram exame de ressonância magnética funcional (RMf) em duas tarefas (cálculos exatos e aproximados ) utilizando paradigma com desenho em bloco em aparelho de 3.0 Teslas. Resultados. O grupo TDAH, quando não medicado (tempo 1) cometeu mais erros aritméticos que os controles (p < 0,001). No entanto, quando em uso de MTF, o grupo TDAH (tempo 2) fez significativamente menos erros quando comparado com a sua linha de base (tempo 1) e quando comparados aos seus controles (tempo 2). Em exercícios de subtração que requerem procedimentos de empréstimos (subtração complexo), o grupo de TDAH (tempo 1) cometeu mais erros do que nos controles, melhorando significativamente quando em uso da medicação (p = 0,039). Em relação à RMf não houve diferenças específicas entre os grupos em cada tarefa isoladamente. Entretanto, houve interação entre o tipo de cálculo (aproximado vs. exato) e grupo (controle vs. TDAH): as crianças com TDAH mostraram atividade diferente do grupo controle na região do cíngulo posterior e pré-cúneo, considerando as duas formas de cálculo. Conclusões. O uso de vários testes aritméticos validados permite uma avaliação abrangente e eficaz de crianças em risco de dificuldades de aprendizagem. Assim, fomos capazes de mostrar que o nosso grupo de crianças com TDAH tinha dificuldades aritméticas significativas, mas o tratamento com MTF trouxe melhoras substanciais. A melhora observada foi no desempenho geral e, especificamente, para o desempenho em subtração complexa. Esta melhora pode ter sido devido ao aumento de habilidades de memória de trabalho, gerando menos erros involuntários. Em relação aos resultados de RMf mostramos um resultado ainda não descrito na literatura: a alteração na região posterior do giro do cíngulo e pré-cúneo que possivelmente se deve a alteração funcional intrínseca do TDAH na vigência de medicação com metilfenidato, uma área que já foi descrita na literatura sobre TDAH porém não nessa condição / Objective. To evaluate arithmetic function in children with Attention Deficit Hyperactivity Disorder (ADHD) and to determine whether stimulant treatment affects their performance (clinical arm), besides verifying the patterns of neural activation on a subgroup from this sample during trials testing arithmetical calculation (neuroimaging arm). Methods. Forty-two kids (from 9 to 12 years old) took part in the clinical arm: 20 with ADHD diagnosed according DSM-IV criteria and 22 from control group. These children were classified with or without arithmetic difficulties based on their performance on three arithmetic tests used in Brazil. All participants from the clinical arm were evaluated at 2 time points: time 1 and time 2 when ADHD children were on methylphenidate (MPH) at a dose of 0,3/0,5 mg/kg. Global performance in arithmetic, and specifically, subtraction in these two times was explored. We also evaluate 10 ADHD children (6 of these from the clinical arm) on MPH and 10 healthy control children (8 of these from the clinical arm) using fMRI (Functional Magnetic Resonance Imaging) during two trials testing approximate and exact arithmetical calculation using a block design paradigm in a 3.0 Teslas device. Results. The ADHD group, when unmedicated (time 1) made more arithmetic errors than controls (p < 0,001). However, when on MPH, ADHD group (time 2) made significantly fewer errors when compared to their baseline (time 1) and when compared to their controls (time 2). On subtraction exercises that require borrowing procedures (complex subtraction), the ADHD group (time 1) committed more errors than controls, while significantly improvement in the medicated state (p = 0,039). Regarding the fMRI there was no specific difference between groups on each task isolated. However, there was an interaction between the type of calculation (approximate vs. exact) and group (control vs. ADHD): children with ADHD showed different activity from the control group in the posterior cingulate and precuneus, considering both forms of calculation. Conclusions. The use of multiple validated arithmetic tests enables a comprehensive and effective assessment of children at a risk for learning difficulties. Thus, the study was able to show that the ADHD group had significant arithmetic difficulties; on the other side MPH treatment brought substantial improvement. This mentioned improvement was observed in general development, and specifically on complex subtraction performance, what could have been caused by the increase of working memory skills, generating less involuntary errors. Regarding the fMRI, it brought up results not yet described by literature: the alterations of the posterior cingulate gyrus and precuneus what is possibly due to the intrinsic functional alteration of ADHD on MPH, an area that has already been described by ADHD literature nevertheless not on under this condition

Diss. (sammanfattning) Umeå : Umeå universitet, 2009. / Härtill 5 uppsatser. Även tryckt utgåva.

Le développement de la compétence orthographique est particulièrement difficile pour les dyslexiques. Orthographier en français implique la prise en compte de connaissances et de stratégies variées. Cette étude a pour objectifs de décrire l’utilisation des stratégies de production orthographiques de 32 élèves dyslexiques (ED) âgés de 9 à 12 ans ainsi que d’établir les liens entre les stratégies orthographiques et la compétence orthographique. Les élèves devaient orthographier 24 mots sous dictée et commenter, pour chaque mot, les stratégies employées. Les performances des ED ont été comparées à celles de 25 normo scripteurs de même âge chronologique (CA) et à celles de 24 normo scripteurs de même compétence écrite (CE). Les résultats indiquent que les stratégies phonologiques sont les plus utilisées par tous les groupes de participants. Si aucun type de stratégies n’est lié à la compétence orthographique des ED, la stratégie visuo-orthographique nous éclaire sur les résultats des CA et des CE. / The development of spelling skill is a very difficult task for students with dyslexia. Spelling in French involves the consideration of various knowledge and strategies. This study aims to describe the use of spelling strategies of 32 dyslexic students (ED) aged from 9 to 12 years and to establish the links between spelling strategies and spelling skill. Students had to spell 24 words under dictation and for each word, provide comments on the strategy employed. The performances of dyslexics were compared to 25 children of the same chronological age (CA) and to 24 children of the same writing skill (CE). The results show that phonological strategies are the most commonly used by all groups of participants. If no such strategy is related to the spelling skill of ED, visuo-orthographic strategy generally accounts the results of CA and CE.