La stimulation magnétique transcranienne (SMT) est une technique non invasive qui permet de stimuler le cerveau. Les SMT répétitives (SMTr), c'est-à-dire l'application de nombreuses impulsions magnétiques, sont capable d'induire des modifications de longue durée de l'excitabilité neuronale. La SMT s'est développée dans un but thérapeutique et scientifique. Les effets après la SMTr sur le cortex moteur sont bien documentés chez les individus sains, mais on en sait moins sur la stimulation du cortex préfrontal dorso-latéral (DLPFC).L'objectif de cette thèse était de comparer différents protocoles SMTr sur des sujets sains et de trouver des marqueurs électroencéphalograpiques (EEG) de la réponse ou pas à la thérapie SMTr dans la dépression majeure et bipolaire. La principale originalité de la méthode présentée est la comparaison intra-sujet d'effets entre-protocoles et le développement de techniques de localisation de sources.Nous avons étudié chez 20 sujets sains comment les oscillations corticales sont modulées suite à quatre protocoles SMTr actifs différents, et à un protocole sham utilisé comme contrôle, du DLPFC gauche et en comparant la puissance spectrale d'EEG avant et après SMTr de durée de 15 minutes. Le spectre EEG a été estimé grâce à la transformée de Fourier rapide (FFT) et partitionné en bandes de fréquence selon la classification commune.Nous avons trouvé pour chaque protocole actif une diminution significative de puissance delta et theta sur les électrodes préfrontales gauches, principalement localisées dans le DLPFC gauche. Dans des bandes de fréquences plus hautes, la diminution de puissance dans le DLPFC a été de plus observée dans le DLFPC controlatéral et dépend du protocole de stimulation. Parce que les activités delta et theta sont généralement associées à l'inhibition corticale, ces résultats suggérent que la SMTr du DLPFC diminue transitoirement l'inhibition corticale locale. Aussi, les oscillations d'EEG rapides sont associées à l'excitabilité corticale et on peut conclure que des diminutions observées non spécifiques dans l'activité rapide localisée dans le DLPFC suggérent également une réduction de l'excitabilité corticale.Dans la deuxième expérience, nous avons travaillé sur groupe de patients, souffrant de trouble dépressif majeur (MDD) et de trouble bipolaire (BP). Dans cette étude ouverte, nous avons cherché à déterminer s'il existe des différences d'EEG de repos dans l'activité cérébrale entre patients BP et MDD, et entre les répondeurs et non-répondeurs à la SMTr à 10 Hz en étudiant des biomarqueurs d'EEG. Le protocole SMTr à 10 Hz étaient le même entre patients MDD et BP. Les propriétés EEG dans les deux troubles dépressifs ont été étudiées, en comparant la puissance spectrale des enregistrements pré- et post-SMTr EEG au cours des sessions thérapeutiques chez les patients répondeurs et non-répondeurs.La conclusion est qu'il est possible de distinguer les répondeurs des non-répondeurs au traitement SMTr. Les répondeurs avaient une puissance en basse fréquence plus importante. Une augmentation de puissance alpha a aussi été observée au niveau du cortex cingulaire ventral dans les deux groupes. La comparaison des MDD et BP a révélé une activité significativement plus élevée dans la puissance des bandes thêta et bêta chez les patients BP, principalement localisée dans le cortex préfrontal. / Transcranial magnetic stimulation (TMS) is a non-invasive technique for stimulating the brain. A brief electric current passing through a magnetic coil produces a brief, high-intensity magnetic field which stimulates the brain. Repetitive TMS, application of many magnetic pulses, is able to induce relatively long-lasting excitability changes and nowadays is being developed for various therapeutic and scientific purposes. The after-effects of rTMS over motor cortex are well documented in healthy individuals, however less is known about the stimulation of dorso-lateral prefrontal cortex (DLPFC). The aim of this PhD thesis was to compare different rTMS protocols in healthy subjects and to find neurophysiological EEG biomarkers characteristic for response or not to rTMS therapy in major and bipolar depression. The main originality of presented method is within-subject comparison of between-protocols effects. Additionally, source localisation was performed in both analyses. Here, we studied in 20 healthy subjects how cortical oscillations are modulated by four different active rTMS protocols (1 Hz, 10 Hz, cTBS and iTBS) of the left DLPFC, and by a sham-1Hz protocol used as a control condition, by comparing the spectral power of pre- and post-rTMS electroencephalographic (EEG) recordings of 15 minutes duration. EEG spectrum was estimated with the Fast Fourier transform (FFT) and partitioned using the common physiological frequency. We found for every active protocol a significant decrease of delta and theta power on left prefrontal electrodes, mainly localised in the left DLPFC. In higher frequency bands (beta and gamma), the decrease of power in the DLPFC was also observed additionally in the contralateral DLFPC and depended on the stimulation protocol. Because large delta and theta activity is usually associated with cortical inhibition, these results suggest that rTMS of DLPFC transiently decreases local cortical inhibition. Furthermore, fast EEG oscillations are associated to cortical excitability and it can be concluded that observed decreases in fast activity, unspecific to protocol, localised in the DLPFC also suggest reduced cortical excitability, which accompanies a decrease in cortical inhibition. In the second experiment we worked on two subgroups of patients, with major depressive disorder (MDD) and bipolar disorder (BP). In this open study we aimed to examine whether there are EEG differences in resting brain activity between BP and MADD patients, and between responders and non-responders to 10 Hz repetitive transcranial magnetic stimulation (rTMS) by studying EEG biomarkers. Eight MDD (6 females) and 10 BP patients (6 females) were included. The 10 Hz rTMS protocol was the same for MDD and BP. The different patterns of EEG activity in both depressive disorders were studied, by comparing spectral power of pre- and post-rTMS EEG recordings throughout the therapeutic sessions in responders and non-responders.The most important finding is that it is possible to distinguish responders from non-responders to the rTMS treatment. Responders showed significantly higher power of low frequencies. Therefore, an increase of alpha power was observed in ventral cingulate cortex in both groups. The comparison of MDD and BP disorders revealed significantly higher activity in theta and beta bands power in BP patients, mainly localised in prefrontal cortex.

Dans le vieillissement « sain », la préférence pour les stimuli positifs augmente par rapport aux stimuli négatifs. Ce phénomène est appelé « effet de positivité » et peut être observé au niveau comportemental et cérébral. L'objectif principal de cette thèse a été de caractériser les effets de l'âge sur les traitements émotionnels afin d'améliorer notre compréhension des effets de positivité. L'objectif sous-jacent a été d'évaluer dans quelles conditions ces effets peuvent conduire à une plus grande vulnérabilité des personnes âgées face à des situations menaçantes. Une première étude en électroencéphalographie a révélé que l'engagement attentionnel pour des scènes naturelles négatives diminue avec l'âge quel que soit leur niveau d'activation dans une tâche de catégorisation affective. A l'inverse, ce dernier reste inchangé pour les situations positives, conduisant à une réduction des biais de négativité. Une deuxième étude en électroencéphalographie, dont le paradigme était similaire à la première étude, a mis en évidence que les biais de négativité restent préservés avec l'âge lorsque l'évaluation des scènes s'effectue sur la dimension de « tendance à l'action ». Une troisième étude révèle que l'attention volontaire sur les situations d'intérêt des personnes âgées (positives) et sur les processus d'évaluation modulés par l'âge est nécessaire à l'émergence des effets de positivité. Parallèlement à ces travaux, une méthodologie innovante est proposée pour la classification d'états émotionnels des personnes jeunes et âgées sur la base de leurs signaux électroencéphalographiques. Nous avons obtenu des résultats encourageants qui suggèrent la possibilité cette méthode pour implémenter des interfaces cerveau-machine pour protéger les personnes âgées d'une éventuelle vulnérabilité en raison des effets de positivité. L'ensemble de ces travaux suggèrent que les effets de positivité sont les conséquences de changements sur le plan motivationnel de l'individu âgé, touchant principalement les processus d'évaluation émotionnel. La personne âgée régulerait ses émotions et diminuerait l'impact des émotions négatives lorsque d'autres motivations plus prioritaires sont absentes. / With aging, the preference for positive stimuli increases compared to negative stimuli. This is called “positivity effect” and it may be observed in both behavior and brain activity. The main goal of this work was to characterized age effects on emotional processing to improve our understood of this positivity effect. The second goal was to evaluate in which conditions these effects could make older people more vulnerable when they are confronted to threatening situations. A first EEG study revealed that the attentional engagement decreased with age for negative stimuli, regardless of their activation level, in an affective categorization task. Conversely, the processing of positive stimuli was preserved with age and, consequently, a reduction of the negativity bias was observed. In a second EEG study, using a similar paradigm to study 1 with the exception of the task which was an “action tendency task”, we observed a preservation of the negativity bias. A third study revealed that the voluntary attention on interest situations for aged adults (positive) and on appraisal process modulated with age was requisite to observe positivity effects. Parallel to this work, a new method was proposed to recognize and classify emotional states based on EEG signals. We obtained encouraging results which suggest the possibility to use this method to elaborate brain-computer interfaces to protect old people against a potential vulnerability due to positivity effect. Taken together, these results demonstrate that positivity effect is due to motivational shifts with age. Older people would be motivated to increase their well-being and would regulate their emotions by reducing the impact of negative stimuli, provided no other more important motivations are absent.

As descobertas relacionadas à neurociência e aos métodos de coleta e análise de dados neurofisiológicos têm fomentado discussões sobre a aplicação desses aspectos em outras campos do conhecimento, dentre eles, o da comunicação. Este estudo tem como objetivo identificar e aferir processos neurais associados à avaliação emocional positiva e negativa de campanhas de segurança no trânsito, de modo a relacioná-los aos apontamentos trazidos pela Prospect Theory (ou Teoria Prospectiva), de que as pessoas tendem a responder de modo diferente ao se alterar apenas a forma de apresentação de um mesmo problema. Tal fato é especialmente importante na comunicação de riscos, em que são frequentemente utilizadas abordagens emocionais negativas como forma de discurso persuasivo. Deste modo, fez-se uma aplicação desses pressupostos ao campo da comunicação, sendo elaboradas duas campanhas experimentais de segurança no trânsito: uma contendo uma perspectiva emocional negativa e outra contendo uma perspectiva emocional positiva. Essas campanhas foram apresentadas em laboratório a 24 voluntários, os quais tiveram sua atividade cortical aferida pelo eletroencefalograma (EEG) e analisada do ponto de vista quantitativo e qualitativo, a fim de verificar uma assimetria frontal hemisférica de ondas alfa e teta nas duas condições, sugerida pela literatura como sendo atrelada a processos emocionais positivos e negativos. Como principais resultados, destacam-se a ocorrência de processos assimétricos significativos tanto na comparação entre as condições (i) neutra e negativa como nas condições (ii) neutra e positiva e (iii) positiva versus negativa, resultados que variaram conforme método de análise empregado. Em termos conclusivos, nota-se a verificação dos processos assimétricos previstos na literatura, porém, com grande variabilidade de amplitude e ocorrência no tempo entre os indivíduos, indicando que a metodologia de coleta com o EEG pode constituir uma forma complementar, e não isolada, de investigação dos processos comunicacionais em relação aos métodos tradicionais de pesquisa qualitativa e quantitativa empregados no campo da comunicação. / The findings related to neuroscience and methods of collection and analysis of neurophysiological data have encouraged discussions on the implementation of those aspects in other fields of knowledge, including communication. This study aims to identify and assess neural processes associated with positive and negative emotional evaluation of traffic safety campaigns, in order to relate them to the Prospect Theory considerations, that people tend to respond differently by changing only the presentation of the same problem. This fact is especially important in the risk communication scenario, which often uses the negative approach as a form of persuasive discourse. Thus, there was an application of these assumptions to the field of communication: two traffic safety campaigns were made: one containing a negative emotional perspective and another containing a positive emotional outlook. These campaigns were presented to 24 subjects in the laboratory, which had their cortical activity measured by electroencephalography (EEG) and analyzed quantitatively and qualitatively, in order to verify a frontal asymmetry of alpha and theta bands in both conditions, suggested by the literature as being linked to positive and negative emotional processes. The main results highlight the occurrence of significant asymmetric activation both in the comparison between (i) neutral and negative conditions as (ii) neutral and positive conditions and (iii) positive versus negative, results that varied according to method of analysis employed. In conclusive terms, there was a verification of asymmetric process verified in the literature, however, with notable variability in amplitude and occurrence in time between individuals, indicating that the methodology of EEG can complement, not in an isolated form, investigations of communication processes in relation to traditional methods of qualitative and quantitative research in the communication field.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-06-14T12:40:33Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese - versao para impressao (2).pdf: 20650405 bytes, checksum: fadce5f7df96f0068f4ff26a711ed388 (MD5) / Made available in DSpace on 2016-06-14T12:40:33Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese - versao para impressao (2).pdf: 20650405 bytes, checksum: fadce5f7df96f0068f4ff26a711ed388 (MD5) Previous issue date: 2014-10-24 / CAPEs / A avaliação da usabilidade representa uma tarefa essencial no ciclo de desenvolvimento do produto ao buscar uma maior satisfação do usuário e, consequentemente, o sucesso do produto no mercado. Para tal, torna-se fundamental a colaboração e a comunicação eficiente entre os diversos membros da equipe. Neste âmbito, tecnologias são desenvolvidas no sentido de promover um design participativo em todas as fases do processo de design e tem provocado uma mudança de paradigmas. O objetivo desta tese consiste em investigar o potencial das principais tecnologias para a usabilidade de produtos, buscando soluções que tornem a avaliação mais eficiente e inclusiva. Uma revisão de literatura sobre usabilidade e métodos é realizada, contextualizando o tema da pesquisa. Em seguida, as tecnologias emergentes da prototipagem virtual, simulações em ambientes virtuais e a interface cérebro-computador, ou neurociência para o design, são identificadas e suas possíveis aplicações na avaliação da usabilidade apontadas. A aplicação das tecnologias emergentes e o relacionamento destas entre si é avaliada em dois estudos de caso. O primeiro estudo consiste em dois experimentos com profissionais e estudantes de Design. Um questionário foi aplicado para investigar a situação atual da aplicação das tecnologias prototipagem virtual e realidade virtual, como também realizou-se um estudo comparativo entre protótipos. No segundo estudo, um teste de usabilidade com usuários reais utilizando um sistema EEG wireless foi realizado para investigar as atividades cerebrais durante o uso de um produto de consumo. Como resultado, várias lições foram aprendidas, correspondendo a uma importante contribuição para pesquisas no campo do design de produtos. A tese é finalizada com as lições aprendidas e são apresentadas sugestões para futuras pesquisas. / The usability evaluation is an essential task in the product development process to seek a greater user satisfaction and, consequently, the product success in the marketplace. For this, it is necessary the collaboration and effective communication among stakeholders. In this context, technology is developed in order to promote a participatory design at all stages of the design process and has resulted in a paradigm shift. The aims of this thesis are to investigate the potential of key technologies for testing the usability of products, and exploring solutions that make usability evaluation more efficient and comprehensive. A comprehensive literature review on usability and testing methods is provided by contextualizing the research theme. Then the emergent technologies of virtual prototyping, virtual environment simulation and brain computer interfacing or neuroscience for design are identified and possible applications in usability evaluation are outlined. The emerging technologies, their applications and how they relate to each other are evaluated in two case studies. The first study consists of two experiments with professional settings and with design students. A questionnaire was applied to investigate the present situation of virtual prototyping and virtual reality technologies application, and also a comparative study between prototypes was conducted. In the second study, a usability test with real users using a wireless EEG system was performed to investigate the brain activity during the use of a consumer product. As results show, several lessons were learned, representing an important contribution to research in the field of product design. The thesis concludes with best practices (lessons learned) and suggestions for further research.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-09-21T13:00:49Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Rafaela Queiroz 01.06.16.docx..pdf: 38785641 bytes, checksum: 6a42f06574706d4681fe6f9dadc8b8ec (MD5) / Made available in DSpace on 2016-09-21T13:00:49Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Rafaela Queiroz 01.06.16.docx..pdf: 38785641 bytes, checksum: 6a42f06574706d4681fe6f9dadc8b8ec (MD5) Previous issue date: 2016-01-29 / A embalagem é a interface mais utilizada no cotidiano das pessoas. No entanto, muitas delas apresentam problemas de usabilidade e segurança fazendo com que o seu design proporcione ao usuário falta de segurança, conforto, eficiência e satisfação estética. Particularmente, a dificuldade na abertura da embalagem pode provocar desperdício e até a inutilização do produto. Os estudos relacionados a mensuração da satisfação do usuário de embalagens PET de refrigerante ainda são escassos, principalmente quando relacionados ao desempenho real do usuário no momento da abertura das tampas roscadas. Embora existam técnicas de usabilidade que avaliam a experiência do usuário através do processo de concepção e avaliação de produtos de consumo, nem sempre o pesquisador tem o conhecimento de fato se a experiência relatada pelo usuário no momento da pesquisa condiz plenamente com a experiência real sentida pelo usuário. Este estudo realizou uma avaliação de usabilidade de uma amostra de usuários durante a manipulação manual de embalagens PET de refrigerante através da comparação entre a experiência relatada pelo usuário e a experiência real sentida mensuradas através das técnicas de análise de usabilidade, rastreamento ocular, eletroencefalografia e termografia. No estudo de usabilidade foi solicitado aos voluntários que abrissem duas garrafas PET de refrigerantes e preenchessem um questionário de avaliação de usabilidade para relatar o nível de satisfação no manuseio do produto. Este experimento obteve a experiência relatada pelos usuários a ser comparada com as demais ferramentas que visavam obter a experiência sentida pelos usuários. O rastreamento ocular objetivou analisar o foco de atenção visual dos voluntários para identificar qual seria a sua embalagem preferida numa amostra de duas garrafas PET e se este resultado seria compatível com os obtidos nos demais experimentos. Com o auxílio da Neuroergonomia, a ferramenta de EEG foi aplicada no estudo das atividades elétricas do cérebro dos voluntários durante o tempo da apresentação das garrafas PET associada ao comando de fixar o olhar para a garrafa que o voluntário gostou e não gostou. Foi utilizado o software sLORETA para a análise dos dados. A termografia objetivou a captação de imagens de calor irradiado de partes do corpo dos voluntários para associá- las a eventuais excitações emocionais durante o manuseio do produto. Os resultados demonstraram que da mesma forma que é possível analisar a experiência relatada pelos usuários através da usabilidade, é possível analisar a experiência sentida através das técnicas de rastreamento ocular, EEG e termografia. Também foir comprovado que estas ferramentas demonstraram ser eficazes para mensurar a satisfação (experiência sentida) dos usuários no manuseio de produtos de consumo. / Packaging is the most widely used interface in daily life. However, many of them have problems of usability and safety causing the design provides the user with lack of safety, comfort, efficiency and aesthetic satisfaction. Particularly, the difficulty in opening the package may lead to waste and destruction of the product. Studies related to measurement of PET packaging user satisfaction soda are still scarce, especially when related to the actual performance of the user at the opening of the screw caps. Although there are usability techniques that evaluate the user experience through the process of design and evaluation of consumer products, not always the researcher has the knowledge if the experience reported by the user at time of search matches fully with the actual experience felt by user. This study conducted a usability evaluation of a sample of users during manual handling of soda PET packaging by comparing the user-reported experience and the actual experience felt measured through usability analysis techniques, eye tracking, electroencephalograph and thermography. In the study of usability were asked to volunteer that opened two PET soft drink bottles and complete a usability evaluation questionnaire to report their level of satisfaction in product handling. This experiment got the experience reported by users to be compared with other tools aimed at getting the experience felt by users. The eye-tracking aimed to analyze the focus of visual attention of volunteers to identify what would be your preferred packaging a sample of two bottles PET and this outcome would be consistent with those obtained in other experiments. Supported by Neuroergonomics, EEG was applied in the study of the electrical activity of the brain of the volunteers during the PET bottles of presentation time associated with the command to set the look for the bottle that voluntary liked and disliked. The software sLORETA was used for data analysis. Thermography aimed to capture images from the volunteers radiated heat body parts to associate them with any emotional excitement while handling the product. The results showed that in the same way that you can analyze the experience reported by users through the usability, you can analyze the experience felt through the eye-tracking techniques, EEG and thermography. Also proved that these tools have proven to be effective to measure users’ satisfaction (felt experience) in handling consumer products.

O presente trabalho teve como objetivo caracterizar o sinal cerebral de bovinos quanto a sua complexidade e também a sua extensividade. Para tal foi necessário formar uma base de dados de sinais cerebrais, estes sinais foram adquiridos de novilhas da raça holandesa, na cidade de Pirassununga/SP (latitude 21°59\'46\" Sul e a uma longitude 47°25\'33\" Oeste, altitude de 627 metros) em duas situações: (1) câmara climática (gaiolas de contenção) em junho de 2005 e (2) piquete experimental (animais com liberdade de movimentos), entre outubro e dezembro de 2007. Foram utilizados eletrodos superficiais, fixos a cabeça dos animais por meio de cola sintética, a freqüência de amostragem foi de 120 Hz. Os sinais foram avaliados visualmente e os trechos livres de artefatos foram selecionados para formação da base de dados. Simultaneamente foram considerados temperatura e umidade do ambiente (para o calculo da entalpia), momento da intervenção da equipe junto aos animais e alguns comportamentos apresentados pelos animais durante a aquisição dos sinais. O algoritmo utilizado para calculo da complexidade C(n) mostrou-se eficiente na caracterização de seqüências conhecidas. O método desenvolvido para determinar o parâmetro q quando utilizado para caracterizar um mapa logístico, no limite de comportamento caótico, mostrou que q permanece constante mesmo quando se alteram as condições iniciais, ou seja, q e uma característica do sistema e o método e capaz de verificar este fato. Quando aplicados a base de dados, verificou-se que o parâmetro q variou mais em função de manipulação do animal do que em relação a entalpia, ou seja, o estresse de manipulação se sobrepôs ao estresse térmico, isso pode se verificar mais claramente nos experimentos realizados em câmara climática com os animais mantidos em gaiolas. As variações na complexidade C(n) (entre 0,2 e 1,0) permitem afirmar que os sinais de bovinos apresentam, alem de componentes oscilatórias, componentes caóticas. A metodologia proposta indicou que e possível caracterizar sinais de bovinos quanto a sua extensividade, uma vez que q tende a apresentar valores menores logo após manipulação dos animais. / This study aimed to characterize the bovine brain electrical activity as its complexity and also to this extensiveness. In order to make it possible a database of brain signals was formed. These signals were acquired from Holstein heifers in the city of Pirassununga / SP (latitude 21°59\'46\" south and a longitude 47°25\'33\" west, altitude of 627 meters ) in two situations: (1) climatic chamber (cage containment) in June 2005 and (2) experimental pasture (animals with freedom of movement) between October and December 2007. We used surface electrodes, fixed to the head of the animals by synthetic glue, the sampling frequency was 120 Hz. Signals were evaluated visually and free of artifacts signals were selected to take part in the database. Both, were considered the temperature and humidity from environment (for the calculation of the enthalpy), It was also considered team intervention with the animals and some behaviors displayed by animals during signals acquisition. The algorithm used to calculate the complexity C(n) was efficient in the characterization of known sequences. The method developed to determine the q parameter when used to describe a logistic map in the limit of chaotic behavior, showed that q remains constant even when changing the initial conditions, ie, q is a characteristic of the system and developed methodology is able to verify this fact. When applied to the database, it was found that the q parameter varied more according to manipulation of the animal than on the enthalpy, ie the stress of manipulation overrides to heat stress, this can be verified more clearly in the experiments performed in climatic chamber with the animals kept in cages. Changes in complexity C(n) (between 0.2 and 1.0) show that the animals exhibit signs of oscillatory components in addition to chaotic components. The proposed methodology showed that it is possible to identify cattle signs as to its extensiveness, as q tends to produce lower values after handling animals.

Este trabalho mostra a aplicação das redes de sensores sem fio na monitoração de variáveis fisiológicas de bovinos. A necessidade de experimentar técnicas de coleta de dados, que causem menos perturbações no comportamento natural dos animais de interesse da zootecnia de precisão, foi a principal motivação deste trabalho. Para testar a aplicabilidade da tecnologia das redes de sensores sem fio neste campo, foi desenvolvida uma infra-estrutura, utilizando técnicas de instrumentação eletrônica e comunicação sem fio via rádio-freqüência. A rede foi projetada com o protocolo floating base sensor network (FBSN) que implementa uma topologia adhoc com escolha aleatória dos nós. Os protótipos desenvolvidos foram utilizados para efetuar coletas de sinais cerebrais e temperaturas corporais de bovinos adultos. Foram desenvolvidos também os softwares embarcados e de supervisão e um simulador de deslocamento bovino, que foi utilizado como ferramenta de auxílio no projeto da infra-estrutura de monitoramento implementada. O consumo das fontes de energia e a relação custo-beneficio do sistema foram os principais itens avaliados. Os resultados obtidos mostraram que é possível utilizar redes de sensores sem fio como técnicas eficientes para coleta de dados fisiológicos de bovinos. / This work presents an application of wireless sensor networks technology used for bovine physiological variables monitoring. The main stimulus of this work was the precision animal production researcher\'s interest in developing and testing new techniques that could allow data acquisition with less interference in animal behavior. In order to test the feasibility of the wireless sensor network technology in this area, an infrastructure was developed using electronic instrumentation and radio frequency wireless communication techniques. The network was projected to support the floating base sensor network protocol that is a special kind of adhoc topology with randomic selection of path nodes. The developed prototypes were used to acquire brain electrical activity and body temperature from bovines. The development of supervisor and embedded software and a bovine\'s displacement simulator tool was also described here. The energy consumption and the cost-benefit relationship of the network nodes were the main evaluated features. The results obtained prove that the wireless sensor networks can be considered as an efficient technique to be used to acquire bovine\'s physiological data.

O mundo ainda está enfrentando uma crise financeira, que começou em meados de 2007 e até o momento está longe de ser resolvida. Os mercados de ações ao redor do mundo reagiram mal e as notícias em tempo real nunca desempenharam um papel tão importante para os investidores, como visto nesta crise. Em outras palavras, o impacto dos meios de comunicação aprofundou a dinâmica de baixa dos mercados financeiros, o que é amplificada pela volatilidade intrínseca do mesmo. Assim, a Neuroeconomia veio como um novo campo de questionamentos, o qual tem a finalidade de estudar a tomada de decisão, tendo em conta o papel desempenhado pela emoção e seus aspectos fisio-patológicos. Se utiliza neste estudo uma amostra de oitenta (80) pessoas, classificados em quarenta alunos de graduação e quarenta (40) trabalhadores experientes do mercado financeiro (traders), ambos igualmente divididos em 50% do sexo masculino e 50% do sexo feminino. O escopo é de avaliar o envolvimento de uma ampla rede de circuitos neurais envolvidos na avaliação de riscos, benefícios e conflitos (esta ponderação está intimamente relacionada à serotonina em caso de riscos e benefícios no caso de dopamina) para cada grupo a fim de verificar como reagem neste ambiente. Compreender a funcionalidade de tais sistemas é de fundamental importância para a compreensão da dinâmica do mercado financeiro e de suas anomalias, ou seja, para registrar a percepção de cada indivíduo em relação ao sentimento geral do mercado, seja ele a favor ou adverso. Portanto, o principal objetivo desta tese é mapear a atividade cerebral usando uma técnica desenvolvida por Rocha (2001, 2004 e 2010), operando uma simulação de negociação da Bolsa de Valores BMF&Bovespa, a fim de compreender melhor a neurodinâmica do processo de decisão no mercado de capitais / The world is still facing a financial crisis, which started in mid 2007 and up to now is far from being solved. Stock markets around the world reacted badly and the real time news has never played such an important role to investors as seen in previous crisis. In other words, the impact of the media deepened the bear dynamics of the markets, that is, it amplified the volatility of it. Thus, Neuroeconomics comes as a new field of inquiring that has the purpose of studying decision making taking into consideration the role played by emotion and its physio-pathological aspects. Here, it is used a sample of eighty (80) volunteers, sorted out into forty undergraduate students and forty (40) experienced financial market practioneers (namely traders), both equally divided into 50% male and 50% female. The scope is to evaluate the involvement of a wide network of neural circuits involved in risk assessments, benefits and conflicts (this weighting is closely related to the serotonin neural circuits in the event of risks and benefits in the case of dopamine) so as to verify how both groups react to this environment. Understanding the functionality of such systems is of fundamental importance for understanding the dynamics of the financial market and its anomalies, ie to record the perception of each individual in relation to the general market sentiment, being it in favour or on the contrary, adverse. Therefore, the main objective of this thesis is then to map brain activity using a technique developed by Rocha et al (2001, 2004 and 2010), operating a simulation of trading within the BMF&Bovespa, in order to better understand the process of neurodynamics decision making in the capital market

L’un des phénomènes naturels probablement des plus communs et pourtant des moins compris, la conscience, s’est longtemps trouvé restreint à des considérations purement philosophiques et métaphysiques. Ces dernières décennies, scientifiques et philosophes ont pu s’atteler à son étude, en l’opérationnalisant.Dans le même temps, une quantité croissante de données suggère que notre cerveau est constamment en train de prédire des entrées sensorielles, et que chaque niveau de l’organisation hiérarchique du cortex génère en continu les représentations de telles prédictions, ainsi que le décalage entre ces prédictions et l’entrée réelle.Dans ma thèse, j’ai exploré comment cette capacité surprenante de notre cerveau à générer des prédictions est connectée à notre expérience consciente.Plus spécifiquement, j’ai étudié comment ces prédictions peuvent impacter les traitements inconscients, et la différence par rapport aux traitements conscients. Ce travail montre que la latéralisation de l’activité électrophysiologiqueoscillatoire du cerveau peut être un marqueur important; et comment les prédictions affectent le traitement inconscient. De plus,il montre que les attentes peuvent entrainer un traitement inconscient au point d’impacter un comportement orienté vers un but. Il souligne également que les prédictions affectant les traitements conscient et inconscientemploient différents mécanismes neuronaux.J’avance l’idée que la conscience pourrait être nécessaire pour le développement de nouvelles prédictions. Finalement, je montre que les prédictions peuvent changer la qualité du traitement inconscient. Intégrant ces résultats à la littérature existante, je discute les caractéristiques d’une possible théorie prédictive de la conscience. / During the last decades, philosophical and scientific developments allowed the flourishing of the scientific study of consciousness. Probably one of the most common and yet least understood of natural phenomena, until last century consciousness was mainly restricted to pure philosophical and metaphysical accounts. Through the operationalization of consciousness, scientists have been able to endeavor in the seemingly elusive investigation of the cognitive function of consciousness.At the same time, an increasing amount of evidence suggests that our brain is constantly predicting its sensory inputs. Each level in the hierarchical organization of the cortex is continuously generating representations of such predictions and also the mismatch between predictions and actual input.The highly structured regularity of sensory information would allow our brain to make predictions about its environment and help it to make sense of the world.In my thesis I explored how the surprising ability of our brains to generate predictions is connected to our conscious experience. More specifically, I investigated how predictions can impact unconscious processes, and the corresponding contrast with respect to conscious processes. In my experimental contributions, I tried to to delineate how behavioral and neural responsesto unconscious stimuli can be affected by predictions. In my first study, I investigated how neural markers of predictive mechanisms can index unconscious behavior, and how predictions can impact unconscious stimulus processing. I show that the lateralization of oscillatory electrophysiological brain activity can be an important marker of how predictionsaffect unconscious processing. Moreover, I show that expectations can drive unconscious processing up to the point of goal-directed behavior.In my second and third studies I investigated the behavioral and electrophysiological responses of unconscious processing under predictive contexts, and how they differ from the conscious ones. I demonstrate that predictions affecting conscious and unconscious processing engage different neural mechanisms. I push forward the idea that consciousness might be necessary for the development of new predictions. Finally, I show that predictions can change the quality of unconscious accumulation of evidence.I discuss how predictions can help to understand the cognitive function of consciousness in the light of these results and other recent developments in the literature. I discuss possible constraints for this contribution under the light of current theories of consciousness.

L’électroencéphalogramme (EEG), mesure de l'activité électrique du cerveau, reste une des meilleures méthodes de prévision non-invasive des résultats neurologiques. L'objectif de notre travail est de développer un système de classification automatique qui prévoit des risques sur la maturation cérébrale, se traduisant par un état pathologique à 2 ans. Les caractéristiques du signal EEG, qui sont utiles à la prévision automatisée, sont traitées via un module appelée EEGDiag, et sont appliquées sur un ensemble de données issues de 397 dossiers de nouveau-nés prématurés. Chaque dossier comprend un enregistrement EEG, et un rapport concernant les informations et les diagnostics de l’enfant à la naissance et 2 ans plus tard (normal, pathologique ou douteux). Pour aider les médecins à prévenir l’état neurologique anormal du nouveau-né prématuré, nous avons développé plusieurs modèles de classification qui s’appliquent sur différentes séries de caractéristiques du signal EEG inspirées des annotations des neuropédiatres. Plusieurs modèles de classification et d’aide à la décision sont testés sur différentes extractions de la base de données afin de fournir aux médecins le système de classification le plus performant. Notre système proposé permet de détecter automatiquement des pronostics sur l’état pathologique du nouveau-né prématuré. Notre travail a consisté à subdiviser l’amplitude des bouffées du signal EEG en trois catégories : faible, moyenne et forte. Cette étude de subdivision a permis de choisir les intervalles associés à ces trois catégories permettant d’augmenter considérablement la performance de notre système de classification automatique. Une analyse de corrélation a permis de détecter des relations d’indépendance et de redondance entre certaines données, ce qui permet de réduire le nombre de variables décisives et de sélectionner ainsi la meilleure série de variables qui ramènent notre système à devenir optimal et plus efficace. Ces études nous ont permis d’atteindre un système de classification automatique basé sur une série de 17 variables avec une exactitude 93.2%. Ce système peut apporter une bonne sensibilité à la prévision de l’état neurologique du nouveau-né prématuré et peut servir comme aide à la décision dans le traitement clinique. / The electroencephalogram (EEG), a measure of the electrical activity of the brain, remains one of the best non-invasive methods for predicting neurological outcomes. The aim of our work is to develop an automatic classification system which predicts risks on cerebral maturation that can lead to a pathological condition at 2 years. The EEG signal characteristics, which are useful for automated prediction, are processed via an application called EEGDiag, and applied to a set of 397 records for premature infants. Each record include an EEG record and a report on infant information and diagnosis at birth and 2 years later (normal, sick or risky). To assist physicians in preventing any abnormal neurological condition of the premature newborn, we have developed several intelligent classification models which can be applied to several series of characteristics of the EEG inspired from the annotations of neuropediatricians. Several classification and decisional aid models have been tested on different extracted databases in order to offer to doctors the best efficient classification system. Our proposed system automatically detects the prognosis of the premature newborn pathological condition. Our work consisted of subdividing the amplitude of EEG signal burst into three categories: low, medium and high. This subdivision study allowed to choose Intervals of these three categories which have served to greatly increase the performance of our intelligent classification system. A correlative data analysis allowed to create an independence and redundancy relation between the data attributes, which reduces the number of decisive parameters and thus selects the best series of parameters that made our system optimal and more efficient. These studies enabled us to achieve a classification system based on a series of 17 parameters with an accuracy 93.2%. This system can provide good sensitivity on predicting the neurological status of premature newborn and can be used as a decisional aid in clinical treatment.