Le traumatisme craniocérébral modéré-grave (TCC) a une prévalence élevée au Canada. Il s'agit d'une condition neurologique qui affecte le fonctionnement cognitif. Parmi ces atteintes cognitives, les fonctions exécutives (FE) et la mémoire prospective (MP) sont particulièrement touchées lors d'un TCC. Cependant, les outils actuels pour les évaluer présentent plusieurs lacunes, dont leur faible validité écologique, ce qui ne permet pas d'avoir un portrait juste du fonctionnement quotidien. Une avenue intéressante pour améliorer la validité écologique est d'utiliser la réalité virtuelle. L'objectif du mémoire était d'examiner la validité d'un scénario multitâches effectué dans un environnement virtuel non-immersif d'appartement (VMT = Virtual Multitasking Test) pour évaluer la MP et les FE chez des adultes ayant subi un TCC modéré-grave et des participants contrôles. Les objectifs spécifiques étaient d'examiner les associations entre la performance au VMT et à des mesures neuropsychologiques traditionnelles (Tour de Londres, Zoo Map Test, CAMPROMPT) ainsi que d'examiner la validité discriminante du VMT afin de voir si celui-ci permet de départager le groupe TCC et le groupe contrôle. Quinze participants ayant subi un TCC modéré-grave (20% de femmes; moyenne de 43,5 ans; moyenne de 80 mois post-TCC) ont été recrutés et appariés à 15 participants contrôles. Les résultats indiquent des corrélations positives et modérées entre une mesure du fonctionnement exécutif (Tour de Londres) et différentes mesures du VMT. Une corrélation positive et modérée entre une mesure de la mémoire prospective (CAMPROMPT) et le score total du VMT est également observées. À l'égard du deuxième objectif, les résultats démontrent que le VMT a une sensibilité de 80% et une spécificité de 73% chez une population ayant subi un TCC modéré ou grave. Ces résultats indiquent que l'utilisation du VMT peut être efficace pour mesurer le fonctionnement cognitif et détecter des difficultés dans une population clinique ayant subi un TCC. / Moderate-severe traumatic brain injury (TBI) is highly prevalent in Canada. It is a neurological condition that can impair cognitive functioning. Among these cognitive impairments, executive function (EF) and prospective memory (PM) are particularly impaired in TBI. However, current tools for assessing these domains have a number of limitations, including low ecological validity, which does not provide an accurate picture of day-to-day functioning. An interesting avenue for improving ecological validity is to use virtual reality. The aim of this study was to examine the validity of a multitasking scenario performed in a non-immersive virtual apartment environment (VMT = Virtual Multitasking Test) to assess PM and EF in adults with moderate-severe TBI and control participants. The specific aims were to examine associations between performance on the VMT and traditional neuropsychological measures (Tower of London, Zoo Map Test, CAMPROMPT), and to examine the discriminant validity of the VMT in terms of its ability to discriminate between the TBI and control groups. Fifteen participants with moderate-severe TBI (20% female; mean 43.5 years; mean 80 months post-TBI) were recruited and matched to 15 control participants. The results indicate moderate correlations between a measure of executive functioning (Tower of London) and various VMT measures. A positive and moderate correlation between a measure of prospective memory (CAMPROMPT) and the VMT total score was also reported. With regard to the second objective, results showed that VMT had a sensitivity of 80% and a specificity of 73% in a population with moderate to severe TBI. These results indicate that the use of the VMT can be effective in measuring cognitive functioning and detecting difficulties in a clinical population with TBI.

Foram poucos os estudos realizados para avaliar a capacidade da cavidade dos seios frontais para a diferenciação sexual. No entanto, a predição do sexo dos indivíduos é o passo mais importante para o desenvolvimento de um perfil biológico confiável durante a análise de restos esqueléticos. O advento da tomografia computadorizada por feixe cônico trouxe uma série de vantagens à clínica odontológica, e a quantidade de pacientes que realizam exames tomográficos para fins de diagnóstico tem aumentado cada vez mais permitindo com que estes dados sejam úteis para propósitos de identificação forense. Neste estudo, o objetivo foi propor uma nova metodologia para avaliar a capacidade de imagens em 3D da cavidade sinusal frontal, provenientes de tomografia computadorizada por feixe cônico, em determinar dimorfismo sexual entre os indivíduos. A amostra da pesquisa foi composta por 130 exames (65 do sexo masculino e 65 do sexo feminino) que foram segmentados e reconstruídos tridimensionalmente. O volume 3D foi exportado em formato Tiff nas normas frontal, lateral e basal. E as seguintes variáveis foram mensuradas em um segundo programa: área, perímetro, retângulo delimitador, elipse delimitadora, circularidade, razão de aspecto, arredondamento do objeto, solidez e diâmetro de Feret. O estudo foi capaz de demonstrar a existência de dimorfismo sexual com uma acurácia do modelo final de regressão logística igual a 80,0%. A norma basal foi a que garantiu maior poder de explicação na equação final. A metodologia foi validada e os resultados mostraram alto grau de confiabilidade. / There were few studies to assess the ability of the cavity of the frontal sinuses for sexual differentiation. However, the prediction of the sex of the individuals is the most important step in the development of a reliable biological profile during analysis of skeletal remains. The advent of cone beam computed tomography brought a number of advantages to the dental clinic, and the number of patients undergoing CT scans for diagnostic purposes has increased increasingly allowing that these data are useful for forensic identification purposes. The study aimed to propose a new methodology to assess the 3D images capacity of the frontal sinus cavity, from computed tomography cone beam, to attribute sexual dimorphism between individuals. The survey sample consisted of 130 exams (65 male and 65 female) who were reconstructed three-dimensionally. The 3D volume was exported in Tiff format in the frontal, side and basal views. In addition, the following variables were measured in a second program: area, perimeter, bounding rectangle, ellipse fit, circularity, aspect ratio, roundness, solidity and Feret\'s diameter. The study was able to demonstrate the existence of sexual dimorphism with an accuracy of the final logistic regression model equal to 80.0%. The basal view assured greater explanatory power in the final equation. The methodology has been validated and the results showed a high degree of reliability.

INTRODUÇÃO. Embora esteja bem estabelecida a relação neuropatológica da síndrome de Down (SD) com a doença de Alzheimer (DA), os primeiros sintomas de demência na população com SD são considerados atípicos. Estudos indicam que os sintomas iniciais estão relacionados à disfunção comportamental que envolvem circuitos cerebrais fronto-subcorticais, como mudança de comportamento e disfunção executiva. O presente estudo teve como objetivo investigar fatores associados ao funcionamento do lobo frontal (disfunção executiva, desinibição e apatia) durante o declínio cognitivo e a DA em adultos com SD. MÉTODOS. 92 indivíduos com SD com idade acima de 30 anos foram alocados em três diferentes grupos diagnósticos (cognição estável, demência prodrômica e DA) por meio da avaliação com o instrumento Exame Cambridge para Transtornos Mentais em Adultos com Síndrome de Down e Deficiência Intelectual (CAMDEX-DS), previamente validado como parte da metodologia de trabalho. Os participantes foram avaliados com um protocolo de funções executivas desenvolvido para pessoas com deficiência intelectual por pesquisadores da Universidade de Cambridge e classificados para a presença de disfunção executiva, desinibição e apatia através da entrevista com um informante utilizando a Escala de Personalidade Frontal. Além disso, dados sobre características de comportamentos resultantes de disfunções frontais, memória e orientação foram analisados por meio do CAMDEX-DS em conjunto com uma amostra inglesa totalizando amostra combinada de 162 participantes com SD com mais de 30 anos e divididos em quatro grupos: cognição estável abaixo de 45 anos, cognição estável acima de 45 anos, demência prodrômica e DA. RESULTADOS. Os relatos de disfunção executiva, desinibição e apatia através da Escala de Personalidade Frontal foram correlacionados com o desempenho cognitivo dos participantes: quanto maior a disfunção comportamental nestas áreas, pior o desempenho cognitivo nas tarefas executivas. A desinibição e a disfunção executiva foram associadas aos diferentes diagnósticos. A probabilidade de ter DA aumentou com elevações nos escores da Escala de Personalidade Frontal (p <= 0,5). Na análise com o CAMDEX-DS, os sintomas frontais, assim como as queixas de memória e orientação, estavam presentes antes da evidência de declínio cognitivo. Diante do diagnóstico prodrômico e de DA, esses sintomas se agravaram. O impacto da deterioração cognitiva ocorreu em memória e orientação (odds ratio 35,07; P < 0,001) e disfunção executiva (odds ratio 7,16; P < 0,001) para o grupo prodrômico em relação à cognição estável; desinibição (odds ratio 3,54; P = 0,04) para DA em relação ao grupo prodrômico; e apatia (odds ratio 34,18; P < 0,001) para DA em relação à cognição estável. CONCLUSÃO. Disfunção executiva, desinibição e apatia estiveram presentes em indivíduos com SD e cognição estável. Estas medidas se agravam no declínio cognitivo inicial (prodrômico) e na DA nessa população e estão associados ao desempenho cognitivo em tarefas de funções executivas. Disfunções comportamentais devem ser levadas em consideração durante a avaliação clínica. Estudos futuros considerando a interseção entre neuropatologia, conectividade cerebral e expressão de comportamento podem agregar conhecimento sobre a base e a natureza dessas associações e servirem de base para a criação de estratégias preventivas eficazes / INTRODUCTION. Although a neuropathological correlation has been established between Down syndrome (DS) and Alzheimer\'s disease (AD), the early symptoms of dementia present atypically in the DS population. There is evidence that frontal-subcortical circuits play an important role in the initial presentation of dementia in DS, including changes in behaviour and executive dysfunction. The present study aimed to investigate factors associated with frontal lobe functioning (executive dysfunction, disinhibition and apathy) during cognitive decline and AD in adults with DS. METHODS. 92 individuals with DS aged over 30 years were evaluated and divided into three groups of diagnosis (stable cognition, prodromal dementia and AD) using the Cambridge Examination for Mental Disorders in Adults with Down Syndrome and others with Intellectual Disability (CAMDEX-DS), previously validated as part of our methodology. Participants were assessed with an executive function protocol developed for people with intellectual disabilities by researchers from University of Cambridge, and were rated for executive dysfunction, disinhibition and apathy by an informant using the Frontal Systems Behavior Scale (FrSBe). In addition, data on characteristics of frontal behaviour, memory and orientation were analysed through CAMDEX-DS in conjunction with an English sample totalling 162 participants with DS over 30 years old and divided into four groups: stable cognition under 45 years, stable cognition above 45 years, prodromal dementia and AD. RESULTS. Reports of executive dysfunction, disinhibition and apathy through FrSBe were correlated with participants\' cognitive performance: the higher the behavioural dysfunction in these areas, the worse the cognitive performance in executive tasks. Disinhibition and executive dysfunction were associated with diagnoses. The odds of having AD increased in parallel with increases in FrSBe scores (p <= 0.5). In the CAMDEX-DS analysis, amnestic and non-amnestic symptoms were found to be present before there was evidence of a cognitive decline. During the progression to dementia, those symptoms tended to worsen. Memory and orientation were poorer in the prodromal dementia group than in the stable cognition group (odds ratio 35.07, P < 0.001) as was executive function (odds ratio 7.16, P < 0.001). Disinhibition was greater in the AD group than in the prodromal dementia group (odds ratio 3.54, P = 0.04), and apathy was more pronounced in the AD group than in the stable cognition group (odds ratio 34.18; P < 0.001). CONCLUSION. Executive dysfunction, disinhibition and apathy were present in individuals with DS and stable cognition. These measures hasten the initial cognitive decline of AD and are related with cognitive performance in executive function tasks. Frontally mediated behaviour should be taken into consideration during the clinical evaluation of adults with DS. Future studies considering the intersection of neuropathology, brain connectivity, and behaviour may aggregate knowledge about the basis and nature of these associations, leading to the development of effective preventive strategies

INTRODUÇÃO. Embora esteja bem estabelecida a relação neuropatológica da síndrome de Down (SD) com a doença de Alzheimer (DA), os primeiros sintomas de demência na população com SD são considerados atípicos. Estudos indicam que os sintomas iniciais estão relacionados à disfunção comportamental que envolvem circuitos cerebrais fronto-subcorticais, como mudança de comportamento e disfunção executiva. O presente estudo teve como objetivo investigar fatores associados ao funcionamento do lobo frontal (disfunção executiva, desinibição e apatia) durante o declínio cognitivo e a DA em adultos com SD. MÉTODOS. 92 indivíduos com SD com idade acima de 30 anos foram alocados em três diferentes grupos diagnósticos (cognição estável, demência prodrômica e DA) por meio da avaliação com o instrumento Exame Cambridge para Transtornos Mentais em Adultos com Síndrome de Down e Deficiência Intelectual (CAMDEX-DS), previamente validado como parte da metodologia de trabalho. Os participantes foram avaliados com um protocolo de funções executivas desenvolvido para pessoas com deficiência intelectual por pesquisadores da Universidade de Cambridge e classificados para a presença de disfunção executiva, desinibição e apatia através da entrevista com um informante utilizando a Escala de Personalidade Frontal. Além disso, dados sobre características de comportamentos resultantes de disfunções frontais, memória e orientação foram analisados por meio do CAMDEX-DS em conjunto com uma amostra inglesa totalizando amostra combinada de 162 participantes com SD com mais de 30 anos e divididos em quatro grupos: cognição estável abaixo de 45 anos, cognição estável acima de 45 anos, demência prodrômica e DA. RESULTADOS. Os relatos de disfunção executiva, desinibição e apatia através da Escala de Personalidade Frontal foram correlacionados com o desempenho cognitivo dos participantes: quanto maior a disfunção comportamental nestas áreas, pior o desempenho cognitivo nas tarefas executivas. A desinibição e a disfunção executiva foram associadas aos diferentes diagnósticos. A probabilidade de ter DA aumentou com elevações nos escores da Escala de Personalidade Frontal (p <= 0,5). Na análise com o CAMDEX-DS, os sintomas frontais, assim como as queixas de memória e orientação, estavam presentes antes da evidência de declínio cognitivo. Diante do diagnóstico prodrômico e de DA, esses sintomas se agravaram. O impacto da deterioração cognitiva ocorreu em memória e orientação (odds ratio 35,07; P < 0,001) e disfunção executiva (odds ratio 7,16; P < 0,001) para o grupo prodrômico em relação à cognição estável; desinibição (odds ratio 3,54; P = 0,04) para DA em relação ao grupo prodrômico; e apatia (odds ratio 34,18; P < 0,001) para DA em relação à cognição estável. CONCLUSÃO. Disfunção executiva, desinibição e apatia estiveram presentes em indivíduos com SD e cognição estável. Estas medidas se agravam no declínio cognitivo inicial (prodrômico) e na DA nessa população e estão associados ao desempenho cognitivo em tarefas de funções executivas. Disfunções comportamentais devem ser levadas em consideração durante a avaliação clínica. Estudos futuros considerando a interseção entre neuropatologia, conectividade cerebral e expressão de comportamento podem agregar conhecimento sobre a base e a natureza dessas associações e servirem de base para a criação de estratégias preventivas eficazes / INTRODUCTION. Although a neuropathological correlation has been established between Down syndrome (DS) and Alzheimer\'s disease (AD), the early symptoms of dementia present atypically in the DS population. There is evidence that frontal-subcortical circuits play an important role in the initial presentation of dementia in DS, including changes in behaviour and executive dysfunction. The present study aimed to investigate factors associated with frontal lobe functioning (executive dysfunction, disinhibition and apathy) during cognitive decline and AD in adults with DS. METHODS. 92 individuals with DS aged over 30 years were evaluated and divided into three groups of diagnosis (stable cognition, prodromal dementia and AD) using the Cambridge Examination for Mental Disorders in Adults with Down Syndrome and others with Intellectual Disability (CAMDEX-DS), previously validated as part of our methodology. Participants were assessed with an executive function protocol developed for people with intellectual disabilities by researchers from University of Cambridge, and were rated for executive dysfunction, disinhibition and apathy by an informant using the Frontal Systems Behavior Scale (FrSBe). In addition, data on characteristics of frontal behaviour, memory and orientation were analysed through CAMDEX-DS in conjunction with an English sample totalling 162 participants with DS over 30 years old and divided into four groups: stable cognition under 45 years, stable cognition above 45 years, prodromal dementia and AD. RESULTS. Reports of executive dysfunction, disinhibition and apathy through FrSBe were correlated with participants\' cognitive performance: the higher the behavioural dysfunction in these areas, the worse the cognitive performance in executive tasks. Disinhibition and executive dysfunction were associated with diagnoses. The odds of having AD increased in parallel with increases in FrSBe scores (p <= 0.5). In the CAMDEX-DS analysis, amnestic and non-amnestic symptoms were found to be present before there was evidence of a cognitive decline. During the progression to dementia, those symptoms tended to worsen. Memory and orientation were poorer in the prodromal dementia group than in the stable cognition group (odds ratio 35.07, P < 0.001) as was executive function (odds ratio 7.16, P < 0.001). Disinhibition was greater in the AD group than in the prodromal dementia group (odds ratio 3.54, P = 0.04), and apathy was more pronounced in the AD group than in the stable cognition group (odds ratio 34.18; P < 0.001). CONCLUSION. Executive dysfunction, disinhibition and apathy were present in individuals with DS and stable cognition. These measures hasten the initial cognitive decline of AD and are related with cognitive performance in executive function tasks. Frontally mediated behaviour should be taken into consideration during the clinical evaluation of adults with DS. Future studies considering the intersection of neuropathology, brain connectivity, and behaviour may aggregate knowledge about the basis and nature of these associations, leading to the development of effective preventive strategies

Thesis (doctoral)--University of Limburg, Maastricht, 1992. / Summary in Dutch. Includes bibliographical references (p. 109-119)

Foram poucos os estudos realizados para avaliar a capacidade da cavidade dos seios frontais para a diferenciação sexual. No entanto, a predição do sexo dos indivíduos é o passo mais importante para o desenvolvimento de um perfil biológico confiável durante a análise de restos esqueléticos. O advento da tomografia computadorizada por feixe cônico trouxe uma série de vantagens à clínica odontológica, e a quantidade de pacientes que realizam exames tomográficos para fins de diagnóstico tem aumentado cada vez mais permitindo com que estes dados sejam úteis para propósitos de identificação forense. Neste estudo, o objetivo foi propor uma nova metodologia para avaliar a capacidade de imagens em 3D da cavidade sinusal frontal, provenientes de tomografia computadorizada por feixe cônico, em determinar dimorfismo sexual entre os indivíduos. A amostra da pesquisa foi composta por 130 exames (65 do sexo masculino e 65 do sexo feminino) que foram segmentados e reconstruídos tridimensionalmente. O volume 3D foi exportado em formato Tiff nas normas frontal, lateral e basal. E as seguintes variáveis foram mensuradas em um segundo programa: área, perímetro, retângulo delimitador, elipse delimitadora, circularidade, razão de aspecto, arredondamento do objeto, solidez e diâmetro de Feret. O estudo foi capaz de demonstrar a existência de dimorfismo sexual com uma acurácia do modelo final de regressão logística igual a 80,0%. A norma basal foi a que garantiu maior poder de explicação na equação final. A metodologia foi validada e os resultados mostraram alto grau de confiabilidade. / There were few studies to assess the ability of the cavity of the frontal sinuses for sexual differentiation. However, the prediction of the sex of the individuals is the most important step in the development of a reliable biological profile during analysis of skeletal remains. The advent of cone beam computed tomography brought a number of advantages to the dental clinic, and the number of patients undergoing CT scans for diagnostic purposes has increased increasingly allowing that these data are useful for forensic identification purposes. The study aimed to propose a new methodology to assess the 3D images capacity of the frontal sinus cavity, from computed tomography cone beam, to attribute sexual dimorphism between individuals. The survey sample consisted of 130 exams (65 male and 65 female) who were reconstructed three-dimensionally. The 3D volume was exported in Tiff format in the frontal, side and basal views. In addition, the following variables were measured in a second program: area, perimeter, bounding rectangle, ellipse fit, circularity, aspect ratio, roundness, solidity and Feret\'s diameter. The study was able to demonstrate the existence of sexual dimorphism with an accuracy of the final logistic regression model equal to 80.0%. The basal view assured greater explanatory power in the final equation. The methodology has been validated and the results showed a high degree of reliability.

Made available in DSpace on 2016-03-15T19:40:17Z (GMT). No. of bitstreams: 1 Gabriel Gaudencio do Rego.pdf: 1139897 bytes, checksum: b56f45681ad1b3adb1fbebc620c7562a (MD5) Previous issue date: 2014-08-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Games are useful tools to simulate social interactions of cooperation or competition and can be applied in conjunction with behavioral and electrophysiological techniques, such as Event Related Potentials (ERP) analysis. The Ultimatum Game (UG) is a well-studied game which can be used to investigate how individuals react to injustice. An initial value is divided between a proponent, who suggests a division rate of this value, and a respondent, who may accept or reject it. If the respondent accepts, both players gain the proposed value, and if he or she rejects, they gain nothing. The behavioral and electrophysiological results have demonstrated typical reactions in the game. The Medial Frontal Negativity (MFN), a component associated with the automatic processing of negative social feedback, and the P300, associated with attention and memory process, are two components commonly observed during UG. While the interaction between volunteers and proponents with typical development is well described, the interaction between volunteers and proponents with Down syndrome is still unknown. This research aimed to investigate differences in the behavioral data, MFN and P300 in participants playing the UG with a typical proposer and Down proposer. 32 subjects participated in the experiment. Scales of social desirability, moral identity, self-esteem and an implicit association test about Down syndrome were applied. The results showed similar behavioral patterns among proponents and previous data described in the literature. Regarding ERPs, the MFN was not detected and there was greater amplitude of P200 component for proposals of the Down. There was also greater amplitude of P300 for fair proposals of the typical proponent compared to the fair proposals of the Down, and of these two compared to unfair proposals of both. The amplitude of the P300 for proposals of typical was negatively correlated with self-esteem scores. Together, the results suggest that the presence of a player with Down syndrome might influence the perception and expectation of the participants about the game, and this effect could be extended to the interaction with the typical proponent. The absence of MFN suggests that participants do not perceived the unfair proposals as a social negative outcome and P300 suggests that the interaction with the typical proposer was more relevant to the participants. Moreover, this relevance was modulated due to personal characteristics of self-esteem. Further studies are suggested in this area to confirm the hypotheses suggested in the present research. / Os jogos simulam situações sociais relativamente simples de cooperação ou competição e podem ser aplicados conjuntamente às técnicas de pesquisa comportamentais e eletrofisiológicas como a análise de potenciais relacionados a eventos (ERP). Um jogo muito estudado é o Ultimatum Game (UG), que pode ser utilizado para investigar como indivíduos reagem à injustiça. Um valor inicial é dividido entre um propositor, que sugere uma divisão do valor, e um respondente que pode aceitar ou rejeitar. Caso este aceite os dois ganham o valor proposto, caso rejeite ninguém ganha. Os resultados comportamentais e eletrofisiológicos têm demonstrado reações comuns no jogo. Os ERPs mais comuns é o MFN, associado ao processamento automático de feedbacks sociais negativos, e o P300, associado a processos atencionais e de memorização. Enquanto a interação entre sujeitos de pesquisa com propositores de desenvolvimento típico já é bem conhecida, o efeito desta interação com propositores com síndrome de Down ainda é desconhecido. O presente buscou investigar diferenças no padrão comportamental, de MFN e P300 em participantes jogando UG com propositor típico e com Down. 32 sujeitos participaram do experimento. Foram aplicadas escalas de desejabilidade social, identidade moral, de autoestima e um teste de atitudes implícitas frente às pessoas com Down. Os resultados demonstraram padrões comportamentais semelhantes entres os propositores e a literatura. Quanto aos ERPs, o MFN não foi detectado e houve presença de componente P200 para propostas de Down. Houve também maior amplitude de P300 para propostas justas do típico em comparação as justas do Down e destes dois em comparação às propostas injustas de ambos. A amplitude do P300 para propostas do típico apresentaram correlação negativa com escalas de autoestima. Os resultados sugerem que a presença de um jogador com síndrome de Down influenciou a percepção e expectativa dos participantes quanto ao jogo, e que este efeito pode ter se estendido para a interação com o propositor típico. A ausência de MFN sugere que não houve processamento das propostas injustas como respostas sociais negativas e o P300 sugere que a interação com o propositor foi de maior relevância para os participantes. Além disto, esta relevância foi modulada em razão de características pessoais de autoestima. São sugeridos novos estudos no tema para confirmar as hipóteses aqui apresentadas.

La construction de la représentation de soi est basée sur l'intégration des informations que l'on reçoit des différentes modalités sensorielles telles que les informations visuelles, auditives, tactiles ou proprioceptives. L'interaction entre les actions et les mouvements, et plus récemment les interactions sociales et l'espace ont été étudiées essentiellement au niveau comportemental, moins au niveau fonctionnel et beaucoup reste encore à élucider. En particulier, il est important et essentiel de comprendre exactement quels processus sont impliqués dans la construction d'une représentation spatiale et comment ces processus sont mis en oeuvre, non seulement au niveau local par l'activité de neurones spécifiques, dans une zone corticale spécifique, mais aussi à l'échelle du réseau dans son ensemble ainsi qu'à l'échelle du cerveau entier. Le premier axe de ma thèse s'intéresse à l'espace peripersonnel, qui est l'espace le plus proche de nous et qui représente l'un des sous-espaces fonctionnels de la représentation spatiale. Nous faisons l'hypothèse que ce sont les mêmes régions qui contribuent à la convergence multisensorielle, à la prédiction des conséquences sur le traitement tactile d'une stimulation visuelle approchant le corps et à la construction de l'espace peripersonnel. Pour tester cette hypothèse, nous avons étudié l'effet des aspects prédictifs temporels et spatiaux d'un stimulus visuel dynamique sur la détection du stimulus tactile chez l'Homme (étude comportementale) et le primate non humain (étude en IRM fonctionnelle) ainsi que les bases neuronales de la représentation de l'espace proche et de la représentation de l'espace lointain, chez le primate non humain (étude en IRM fonctionnelle). Nous mettons en évidence l'implication d'un réseau parieto-frontal, essentiellement composé par l'aire intrapariétale ventrale VIP et l'aire prémotrice F4 qui sont activées par ces trois mécanismes différents. Nous proposons que ce réseau traite non seulement la trajectoire de l'objet approchant vis-à-vis du corps, mais qu'il anticipe également ses conséquences sur le corps et prépare des actions de protection en réponse à ce stimulus approchant. Le deuxième axe de ma thèse porte sur la caractérisation de l'étendue de la plasticité dans la représentation visuelle dans le cerveau adulte (par opposition aux premiers stades de plasticité observées autour des périodes critiques du développement) et en particulier, sur des développements méthodologiques permettant de mesurer les changements fins dans le cortex visuel induits par une telle plasticité. Plus précisément, nous avons développé un ensemble de méthodes d'IRM à haute résolution : imagerie fonctionnelle (cartographie visuelle à haute résolution, IRM au repos), pharmacologique (imagerie spectroscopique du GABA) et structurelle (IRM anatomique, DTI basée sur la diffusion des molécules d'eau), afin de définir des mesures de référence pour évaluer les changements induits par la plasticité à différents moments après son induction, à travers une étude longitudinale réalisée chez les mêmes animaux. Certaines de ces méthodes nécessitent encore quelques raffinements et ajustements mais, dans l'ensemble, elles montrent leur potentiel prometteur pour étudier la plasticité chez les primates non humains. Dans l'ensemble, ce travail de thèse a permis de créer un lien fonctionnel entre les études d'IRMf effectuées chez l'Homme et les études d'enregistrement d'électrophysiologies chez le primate non humain. De plus, il entraine de nouvelles stratégies et pistes d'explorations à étudier dans le domaine de la représentation spatiale, à la fois chez l'Homme et le primate non humain / The construction of the representation of self is based on the integration of information received by our different sensory modalities such as visual, auditory, tactile or proprioceptive information. The interaction between actions and movements and more recently social interactions and space are being explored at the behavioral level, but less so at the functional level and much more remains to be elucidated. In particular, it is important and fundamental to understand exactly which processes are involved in space representation and how, not only from a partial view focusing on specific cortical areas and single neuron processes but at the scale of the whole brain and the functional networks. The first axis of my thesis focuses on peripersonal space, that is the space that is closest to us, and represents one of the functional subspaces of spatial representation. We assume that it is the same regions that contribute to multisensory convergence, to the prediction of the consequences of a looming visual stimulus onto tactile processing and to the construction of peripersonal space. To test this hypothesis, we investigated the effect of the temporal and spatial predictive aspects of a dynamical looming visual stimulus onto tactile stimulus detection in humans (behavioral study) and non-human primates (fMRI study); the neural bases of near space and far space representations, in non-human primate (fMRI study). We highlight the involvement of a parieto-frontal network, essentially composed by the ventral intraparietal area VIP, the premotor area F4 as well as striate and extra-striate cortical regions, which are activated by these three different mechanisms. We propose that this network not only processes the trajectory of the looming object with respect to the body, but also anticipates its consequences onto the body and prepares protective actions in response to the looming stimulus. The second axis of my thesis focuses on characterizing the extent of plasticity in the visual representation of the adult brain (as opposed to the early stages around the critical developmental periods) and in particular, how the associated fine-grained changes in the visual cortex can be precisely quantified along multiple dimensions (anatomical, functional, pharmacological). Specifically, we have developed a set of high-resolution MRI methods to assess functional (high-resolution visual mapping fMRI, rs-MRI), pharmacological (GABA spectroscopy imaging) and structural (anatomical MRI, DTI) imaging to define reference measures against which to evaluate the changes induced by plasticity at different times after its induction, through a longitudinal study performed in the same animals. Some of these methods need to be more refined but they show that they are really promising to study plasticity in nonhuman primate. On the whole, this present doctoral research allows to make a functional link between human fMRI studies and monkey single cell recording studies and provides new strategies and explorations to perform on the spatial representation field both in humans and non-human primates

The experiment tested the hypothesis that the acetylcholine (ACh) release in the rat auditory cortex is greater in rats undergoing auditory classical conditioning compared to rats in a truly random control paradigm where no associative learning takes place and that this is mediated by prefrontal afferent projections influencing the nucleus basalis magnocellularis (NBM), which in turn modulates ACh release in neocortex. Rats with bilateral ibotenic acid lesions of medial prefrontal and agranular insular cortices were tested in an auditory classical conditioning task while ACh was collected from the primary auditory cortex. It was hypothesized that lesions of these prefrontal areas would prevent learning-related increases of ACh release in the primary auditory cortex. The hypothesized results were supported. Results from this experiment provide unique evidence that medial prefrontal cortex projections to the NBM are important for mediating cortical ACh release during associative learning.

This master's work was focused on the assessment of sexual dimorphism of external and internal morphology of frontal bone. Sexual diagnosis based on external surface of frontal bones and volume and surface of frontal sinuses was carried out using geometric morphometrics methods. Our approach used anonimized CT scans of 103 skulls from recent Czech population, from which 3D models of frontal bones and frontal sinuses were created. At first the analysis was aimed at studying form and shape of external surface of frontal bone. Our methodology is based on the work of Musilová et al. (2016) that estimates sex using exocranial surface of the entire skull. We analyzed variability and tested differences in males and females frontal bones. The main target of this work was sex classification. The highest success rate acquired 86,41 % with the first 20 main components of form. The following part of this study was focused on sex estimation using the methodology developed by Bulut et al. (2016), which was applied in Turkish population. This method classified Czech males and females with accuracy 70,87 %. In order to complete sex determination based on the frontal bone we also used classification of the radius of the frontal bone curvature with success rate of 77,66 %. The attention was also paid to studying...