Orientador: Prof. Dr. Francisco José Fraga da Silva / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia da Informação, 2014. / Entende-se por ouvido absoluto a capacidade de produzir e/ou identificar e dar nome à frequência de qualquer nota musical sem a necessidade de uma referência externa. O estudo do ouvido absoluto pode ser uma oportunidade única para se investigar as interações entre informações linguísticas e não-linguísticas na memória de estímulos auditivos, juntamente com questões relativas à plasticidade cerebral, períodos críticos e genética. Contudo, se faz necessária a elaboração de um protocolo adaptado para a coleta e análise adequada dos potenciais evocados auditivos desta população. O objetivo desta pesquisa foi desenvolver um protocolo oddball adaptado para gerar, gravar e analisar os potenciais evocados auditivos relacionados a eventos, capaz de investigar as possíveis diferenças no processo cognitivo de músicos com e sem ouvido absoluto em resposta a estímulos auditivos. O método envolveu a manipulação dos parâmetros de coleta e de análise do EEG, assim como a aplicação dos protocolos elaborados em participantes com ouvido absoluto ou com ouvido relativo, para avaliação dos próprios protocolos desenvolvidos e realização das modificações necessárias para aperfeiçoá-los. Os resultados sugerem uma alta influência dos parâmetros adotados na configuração da onda dos componentes analisados, o N1 e o P3. De todos os protocolos desenvolvidos, o protocolo 5 mostrou ser o mais adequado, pois elimina viés de sincronismo do sinal, favorece a configuração da onda e minimiza a influência de habilidades secundárias, como o piano absoluto e o ouvido quasi absoluto.

Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-04-06T13:41:06Z No. of bitstreams: 1 CintiaMota CardealTese2014.pdf: 2995266 bytes, checksum: 4704c3b2f9fabf12e53e2d59ca4d1e83 (MD5) / Made available in DSpace on 2017-04-06T13:41:06Z (GMT). No. of bitstreams: 1 CintiaMota CardealTese2014.pdf: 2995266 bytes, checksum: 4704c3b2f9fabf12e53e2d59ca4d1e83 (MD5) Previous issue date: 2014-02-21 / This study aimed to analyze the profile of executive function and neuroelectrical activations answers from the P300 component of school under acute stimuli of exercise at different intensities . The sample consisted of 60 individuals , divided randomly into control group , experimental group to the experimental group and moderate exercise to intense exercise aged 7 to 14 years . Initial tests to characterize the sample and spirometry for verification and determination of VO2max values for exercise intensity were applied . And the second time were applied cognitive tests ( Flanker and oddball paradigm ) moderate or intense physical exercise , with the reapplication of cognitive tests after acute exercise . It was observed that held moderate and intense aerobic exercise differ statistically from the control group in the executive function testing and procurement of P300. In testing the intense attention the only group differed significantly from the control group mind. In both tests the intensive group achieved better results compared to the other groups. The neuroelectrical frontoparietal network was established for the Flanker paradigm and frontoparietal network and the temporal to the oddball paradigm. We conclude that the results point to a favorable direction of physical activity in the school of moderate and intense in general. / Essa pesquisa teve como objetivo analisar o perfil das respostas da fun????o executiva e as ativa????es neuroel??tricas a partir do componente P300 de escolares sob est??mulos agudos de exerc??cio f??sico em diferentes intensidades. A amostra foi constitu??da de 60 indiv??duos, divididos de forma aleat??ria em grupo controle, grupo experimental para o exerc??cio moderado e grupo experimental para o exerc??cio intenso com idade entre 7 e 14 anos. Foram aplicados os testes iniciais para caracteriza????o da amostra e a ergoespirometria para a verifica????o do VO2max e determina????o dos valores para intensidade do exerc??cio. E no segundo momento aplicaram-se os testes cognitivos (paradigma Flanker e oddball) o exerc??cio f??sico moderado ou intenso, havendo a reaplica????o dos testes cognitivos logo ap??s o exerc??cio agudo. Foi observado que realizou o exerc??cio aer??bio moderado e intenso se diferenciaram estatisticamente do grupo controle no teste de fun????o executiva e nas aquisi????es do P300. No teste aten????o o somente o grupo intenso se diferenciou significativa mente do grupo controle. Em ambos os testes o grupo intenso obteve melhores resultados em rela????o aos demais grupos. A rede neuroel??trica frontoparietal foi estabelecida para o paradigma Flanker e a rede frontoparietal e temporal para o paradigma oddball. Conclui-se que os resultados apontam para uma dire????o favor??vel da atividade f??sica na escola de forma moderada e intensa, de maneira geral.

Individuals who suffer from amyotrophic lateral sclerosis (ALS) have a loss of motor control and possibly the loss of speech. A brain-computer interface (BCI) provides a means for communication through nonmuscular control. Visual BCIs have shown the highest potential when compared to other modalities; nonetheless, visual attention concepts are largely ignored during the development of BCI paradigms. Additionally, individual performance differences and personal preference are not considered in paradigm development. The traditional method to discover the best paradigm for the individual user is trial and error. Visual attention research and personal preference provide the building blocks and guidelines to develop a successful paradigm. This study is an examination of a BCI-based visual attention assessment in an ALS sample. This assessment takes into account the individual’s visual attention characteristics, performance, and personal preference to select a paradigm. The resulting paradigm is optimized to the individual and then tested online against the traditional row-column paradigm. The optimal paradigm had superior performance and preference scores over row-column. These results show that the BCI needs to be calibrated to individual differences in order to obtain the best paradigm for an end user.

Amyotrophic lateral sclerosis and other neurodegenerative disorders can cause individuals to lose control of their muscles until they are unable to move or communicate. The development of brain-computer interface (BCI) technology has provided these individuals with an alternative method of communication that does not require muscle movement. Recent research has shown the impact psychological factors have on BCI performance and has highlighted the need for further research. Working memory is one psychological factor that could influence BCI performance. The purpose of the present study is to evaluate the relationship between working memory and brain-computer interface performance. The results indicate that both working memory and general intelligence are significant predictors of BCI performance. This suggests that working memory training could be used to improve performance on a BCI task.

The effects of neurodegenerative diseases such as amyotrophic-lateral sclerosis (ALS) eventually render those suffering from the illness unable to communicate, leaving their cognitive function relatively unharmed and causing them to be “locked-in” to their own body. With this primary function compromised there has been an increased need for assistive communication methods such as brain-computer interfaces (BCIs). Unlike several augmentative or alternative communication methods (AACs), BCIs do not require any muscular control, which makes this method ideal for people with ALS. The wealth of BCI research focuses mainly on increasing BCI performance through improving stimulus processing and manipulating paradigms. Recent research has suggested a need for studies focused on harnessing psychological qualities of BCI users, such as motivation, mood, emotion, and depression, in order to increase BCI performance through working with the user. The present studies address important issues related to P300-BCI performance: 1) the impact of mood, emotion, motivation, and depression on BCI performance were examined independently; and 2) pleasant, unpleasant, and neutral emotions were induced in order to determine the influence of emotion on BCI performance. By exploring psychological mechanisms that influence BCI performance, further insight can be gained on the best methods for improving BCI performance and increasing the number of potential BCI users. The results from Study 1 did not reveal a significant relationship between any of the four psychological factors and BCI performance. Since previous research has found a significant impact of motivation and mood on BCI performance, it may be the case that these factors only impact performance for some individuals. As this is the first study to directly investigate the impact of emotion and depression on BCI performance, future research should continue to explore these relationships. The results from Study 2 were inconclusive for the pleasant condition, since it appears the pleasant emotion manipulation was unsuccessful. The findings indicate that unpleasant emotions do not have a significant impact on BCI performance. This result is promising since it indicates that individuals should still be able to use the BCI system to communicate, even when they are experiencing unpleasant emotions. Future research should further explore the impact of pleasant emotions on BCI performance.

The Correct Response Negativity (CRN) is an event-related potential component that is affected by the act of deception. However, there have been inconsistent findings on the effect of deception on the CRN. Suchotzki, et al. (2015) suggested that the design of the paradigm used to elicit the deceptive response is what controls the size of the CRN. Specifically, motivation to deceive changes the size of deception relative to telling the truth. This study attempted to follow up on suggestions made by Suchotzki et al. (2015) to investigate if extraneous motivation to lie does indeed invert the ratio of CRN in lie compared to truth responses in a deception experiment by manipulating the motivation to lie. This study used a modification of the image-based guilty knowledge test (GKT) paradigm used in Langleben et al. (2002). The first hypothesis of this experiments was that a larger CRN during deception relative to truth-telling will be observed when participants are not motivated to lie, while a larger CRN during truth-telling relative to deception will be observed when participants are motivated to lie. The hypothesis was not supported. The second hypothesis of this experiment was that the P300 component would be larger when participants were motivated to lie, as compared to when they were instructed to lie. Results indicated that P300 was significantly higher in the lie conditions than in the truth conditions; however, there was no difference in amplitude as a function of whether they were in the informed or motivated lie condition.

Il apparait de nos jours évident que les cancers ne peuvent se réduire uniquement à des aberrations génétiques, et qu'un nouveau paramètre est à prendre en considération, l'épigénétique. Au cours de ma thèse je me suis efforcé de caractériser la protéine fusion BRD4-NUT. Cette protéine résulte d'une translocation t(15;19) observée dans les carcinomes de la ligne médiane (NMC), extrêmement agressifs et létaux. La protéine BRD4 possède un double bromodomaine capable de s'associer à la chromatine acétylée, et recrute divers facteurs sur la chromatine. NUT est une protéine de fonction inconnue exprimée exclusivement au cours de la spermatogenèse. J'ai pu démontrer que la protéine fusion BRD4-NUT était suffisante pour induire la tumorigenèse, par un mécanisme de séquestration de la proteine histone acétyltransférase (HAT) CBP/p300. NUT interagit avec CBP/p300 et suractive son activité d'acétylation, créant des foci hyperacétylés de chromatine. BRD4-NUT empêche ainsi CBP/p300 d'aller co-activer la transcription de nombreux gènes, et bloque notamment la réponse apoptotique p53-dépendante. Une inhibition de BRD4-NUT – par siRNA, mutation des bromodomaines ou dérégulation de l'acétylation des foci par des inhibiteurs des histones déacétylases (HDAC) – réenclenche la voie d'apoptose et la mort de ces cellules tumorales. Cette étude est un exemple précis de l'impact qu'une dérégulation épigénétique peut avoir sur l'homéostasie cellulaire et son mécanisme d'induction de la tumorigenèse. Je me suis également interessé à caracteriser la protéine NUT lors de son contexte physiologique, la spermatogenèse, ou lors de son expression illégitime dans des lignées tumorales sans fusion avec BRD4. La protéine NUT est exprimée au niveau des stades de maturation des cellules germinales spermatides, et pourrait participer au remodelage du génome et à l'établissement de l'épigénome final du spermatozoïde. Nut semble également conférer un avantage prolifératif lors de son expression anormale dans au moins trois lignées cellulaires, U2OS, A549 et A7R5. Ainsi, la protéine NUT, seule ou fusionnée avec BRD4, est un facteur Cancer/Testiculaire capable d'influer négativement sur l'homéostasie des cellules somatiques dans lesquelles ses fonctions, normalement restreintes à la spermatogenèse, participent à la tumorigenèse.

In order to investigate the temporal characteristics of cognitive processing, we apply multivariate phase synchronization analysis to event-related potentials. The experimental design combines a semantic incongruity in a sentence context with a physical mismatch (color change). In the ERP average, these result in an N400 component and a P300-like positivity, respectively. The synchronization analysis shows an effect of global desynchronization in the theta band around 288ms after stimulus presentation for the semantic incongruity, while the physical mismatch elicits an increase of global synchronization in the alpha band around 204ms. Both of these effects clearly precede those in the ERP average. Moreover, the delay between synchronization effect and ERP component correlates with the complexity of the cognitive processes.

In this study, the effect of semantic information processing was investigated by the oddball paradigm, by presenting consecutive Turkish words or word-like non-words while EEG signals are recorded. In an oddball paradigm, a series of events are presented of which one class is rarer than the other. Subjects are asked to respond to the infrequent stimuli (e.g. press a button, or count the number). The event related potential (ERP) component P300 obtained from EEG is considered as the marker of this attention capturing paradigm. P300 is obtained consistently for both visual and verbal stimulus. On the other hand, the ERP component N400 is consistently associated with semantic processing in neurolinguistics. Additionally, Late Positive Component (LPC) is a marker for the top-down attention mechanism during word comprehension. Moreover, there are other components, called early ERPs, which occur between 100-200 ms after the stimulus onset. These components orthographically and phonologically reflect low-level features of words. The target words chosen for our study are strictly limited to belong to a neutral category and not consist of any emotional content, to rule out emotional interference in semantic processing. Based on the ERP components that were obtained from this study, the LPC potential exhibited for words had higher amplitude than that of non-words consistently and statistically significantly. However, our study was confounded with the heterogeneity of non-words because some of the non-words were non-sense letter sequences while others were pseudowords. Due to this, although we observed the P300 and N400 ERPs consistently for all stimuli, we did not find significant differences for these potentials between words and non-words. To the best of our knowledge, our investigation is one of the few studies conducted with EEG recordings in a task that involved lexical decision making in Turkish.

Brain Computer Interface (BCI) is a direct communication channel between brain and computer. It allows the users to control the environment without the need to control muscle activity [1-2]. P300-Speller is a well known and widely used BCI system that was developed by Farwell and Donchin in 1988 [3]. The accuracy level of the P300-BCI Speller as measured by the percent of communicated characters correctly identified by the system depends on the ability to detect the P300 event related potential (ERP) component among the ongoing electroencephalography (EEG) signal. Different techniques have been tested to reduce the number of trials needed to be averaged together to allow the reliable detection of the P300 response. Some of them have achieved high accuracies in multiple-trial P300 response detection. However the accuracy of single trial P300 response detection still needs to be improved. In this research, two single trial P300 response classification methods were designed. One is based on independent component analysis (ICA) with blind tracking and the other is based on variance analysis. The purpose of both methods is to detect a chosen character in real-time in the P300-BCI speller. The experimental results demonstrate that the proposed methods dramatically reduce the signal processing time, improve the data communication rate, and achieve overall accuracy of 79.1% for ICA based method and 84.8% for variance analysis based method in single trial P300 response classification task. Both methods showed better performance than that of the single trial stepwise linear discriminant analysis (SWLDA), which has been considered as the most accurate and practical technique working with P300-BCI Speller.