Abstract The aim of this study was to discover attention- and inhibitory control-related differences in the electrical activity of the brain in 6- to 9-year-old children who stutter (CWS) compared to typically developed children (TDC). For studies I and II, the study group consisted of 11 CWS (mean age 8.1 years, age range 6.3–9.5 years; all boys) and 19 fluently speaking children (mean age 8.1 years, age range 5.8–9.6 years; 7 girls). In study III, the participants were twelve boys who stutter (mean age 7.97 years, range 6.3–9.5 years) and 12 typically developed, fluently speaking boys (mean age 8.01 years, range 5.8–9.6 years). The CWS were recruited through local speech therapists and special teachers and newspaper advertisements, while controls were recruited from schools and preschools and among families of department staff and friends. Electroencephalography (EEG) was recorded during a visual Go/Nogo task, which forms a conflict between the pre-potent Go-response and inhibition of response in the Nogo condition, demanding inhibitory control. This EEG data was investigated with conventional event-related potentials (ERP) analysis, potential map and global field power (GFP) analysis and a time-frequency analysis including the periods between tasks. In the ERP analysis, the CWS had a delayed N2 component in the Go condition and a poorly defined P3 component. The potential maps and GFP waveforms confirmed the findings in the Go condition, but also revealed differences in the Nogo condition, described as a prolonged and excessive N2component and an absent P3 component in the CWS. These results indicate problems in the evaluation and classification of the stimulus and the response preparation and inhibition of the response. In the time-frequency analysis, the CWS showed reduced occipital alpha power in the “resting” or preparatory period between visual stimuli, particularly in the Nogo condition. Therefore, the CWS demonstrate reduced inhibition of the visual cortex in the absence of visual stimuli, which is likely related to problems in attentional gating. This newly discovered lack of occipital alpha modulation indicates elementary differences in the regulation of visual information processing in CWS. These findings support the view of stuttering as part of an extensive brain dysfunction involving also attentional and inhibitory networks. / Tiivistelmä Tutkimuksen tavoitteena oli tunnistaa tarkkaavuuteen ja inhibitiokontrolliin liittyviä eroja aivojen sähköisessä toiminnassa 6–9-vuotiailla lapsilla, jotka änkyttävät verrattuna tavanomaisesti kehittyviin lapsiin. Osatöissä I ja II koeryhmässä oli 11 änkyttävää lasta (iän keskiarvo 8.1 vuotta, ikäjakauma 6.3–9.5 vuotta) ja verrokkiryhmässä 19 sujuvasti puhuvaa lasta (keskiarvo 8.1 vuotta, jakauma 5.8–9.6 vuotta; 7 tyttöä). Osatyössä III koeryhmässä oli 12 änkyttävää poikaa (keskiarvo 7.97, jakauma 6.3–9.5 vuotta) ja verrokkiryhmässä 12 sujuvasti puhuvaa poikaa (keskiarvo 8.01 vuotta, jakauma 5.8–9.6 vuotta). Koehenkilöitä haettiin puheterapeuttien ja erityisopettajien välityksellä sekä lehti-ilmoituksilla. Verrokkiryhmän osallistujat rekrytoitiin kouluista, esikouluista sekä henkilökunnan ja ystävien perheiden joukosta. Elektroenkefalografia (EEG) rekisteröitiin visuaalisen Go/Nogo-tehtävän aikana. Tehtävässä ennakoidun Go-vasteen ja Nogo-tilanteessa vaadittavan reaktiosta pidättäytymisen välille syntyvä ristiriita kuormittaa inhibitiokontrollia. EEG-dataa arvioitiin herätevasteiden avulla, tutkimalla jännitekarttojen ja koko pään jännitevaihteluiden eroja sekä käyttämällä aika-taajuusanalyysia, mihin sisältyi myös tehtävien välinen aika. Herätevasteanalyysissä änkyttävillä lapsilla oli viivästynyt N2-vaste Go-tilanteessa ja huonosti erottuva P3-vaste. Jännitekarttojen ja koko pään jännitevaihteluiden perusteella tämä löydös vahvistui, mutta ryhmät erosivat toisistaan myös Nogo-tilanteessa. Änkyttävillä lapsilla N2-vaste oli pidentynyt ja voimakkaampi ja P3-vaste puuttui. Löydökset viittaavat ongelmiin ärsykkeen arvioinnissa ja luokittelussa sekä reaktion valmistelussa ja inhibitiossa. Aika-taajuusanalyysissa änkyttävillä lapsilla oli okkipitaalialueilla merkittävästi vähemmän alfataajuista toimintaa tehtävien välisen ”lepotilan” tai valmistautumisvaiheen aikana erityisesti Nogo-tilanteessa. Änkyttävillä lapsilla näköaivokuoren inhibitio ärsykkeen puuttuessa on näin ollen heikentynyt, mikä viittaa häiriöön tarkkaavuuden suuntaamisessa. Tämä todettu alfatoiminnan säätelyn puuttuminen ilmentää perustavanlaatuisia eroja näköärsykkeen käsittelyssä änkyttävillä lapsilla. Löydökset tukevat näkemystä änkytyksestä osana laaja-alaista aivojen toiminnan häiriötä, joka käsittää todennäköisesti myös tarkkaavuuteen ja inhibitiokontrolliin liittyviä verkostoja.

abstract: In most of the work using event-related potentials (ERPs), researchers presume the function of specific components based on the careful manipulation of experimental factors, but rarely report direct evidence supporting a relationship between the neural signal and other outcomes. Perhaps most troubling is the lack of evidence that ERPs correlate with related behavioral outcomes which should result, at least in part, from the neural processes that ERPs capture. One such example is the NoGo-N2 component, an ERP component elicited in Go/NoGo paradigms. There are two primary theories regarding the functional significance of this component in this context: that the signal represents response inhibition and that the component reflects conflict. In this paper, a trial-level method of analysis for the relationship between ERP component potentials and downstream behavioral outcomes (in this case, response accuracy) using a multi-level modeling framework is proposed to provide discriminatory evidence for one of these theories. Following a description of the research on the NoGo-N2, preliminary data supporting the conflict monitoring theory are presented, noting important limitations. Next, an EEG simulation study is presented in which NoGo-N2 data are generated with a known relationship to fabricated reaction time data, showing that, with added levels of complexity and noise within the data, the MLM approach is consistently successful at extracting the known relationships that occur in real NoGo-N2 data. Next, using independent components analysis (ICA) to extract spatiotemporal components that best represent the signal of interest, a well-powered analysis of the relationship between the NoGo-N2 and response accuracy is used to provide strong discriminatory evidence for the conflict monitoring theory of the NoGo-N2. Finally, implications for the NoGo-N2, as well as all ERP components, are discussed with a focus on how this approach can and should be used. the paper concludes with potential expansions of this approach to areas beyond identifying the function of ERP components. / Dissertation/Thesis / Doctoral Dissertation Psychology 2019

La jouissance est un des champs dont la psychanalyse fait usage pour rendre compte de ce qui pourrait expliquer le boitement structurel de la condition humaine, son paradoxe fondamental. Partant d'une épistémologie transcendantale, nous envisageons que, bien que le corps et la psyché ne revêtent pas les mêmes réalités, ils ont certains points d'accroche dont fait partie la jouissance et, bien que le corps ne détermine pas le psychisme, il le contraint. Il est alors proposé ici une hypothèse neuropsychanalytique de la jouissance, l'articulant autour du corps et de l'histoire. La jouissance serait la marque de ce qui a fait événement pour le sujet. Cette description permet de relier ce concept à la neurophysiologie des circuits dopaminergiques qui marquent physiologiquement tant la dimension pulsionnelle, que la dimension événementielle et donc historique.À partir de cette conceptualisation, un paradigme expérimental a été constitué afin d'investiguer cette possibilité d'une accroche entre le psychique et le biologique chez des sujets dépendants, lorsqu'ils sont confrontés à leur objet d'addiction. Concrètement, nous 'osons' l'hypothèse que plus un sujet manifeste d'indices repérables d'une mobilisation pulsionnelle dans son discours libre amorcé par l’objet addictif (dans ce cas-ci, la cigarette pour des fumeurs), plus il aura le geste rapide et sûr pour l’attraper ou des difficultés à inhiber son appétence vers cet objet. Ceci est investigué à travers un outil constitué à partir de la théorie psychanalytique d’une part, et à travers deux tâches de type Go-NoGo (évaluées par des mesures comportementales –temps de réaction et erreurs- et électrophysiologiques -la N2 et la P3, deux marqueurs considérés comme reflétant la signature des processus attentionnels et des biais d’inhibition-, d’autre part. La particularité du paradigme, outre cet usage d’outils issus de champs distincts, réside dans le fait que, à aucun moment, ce n’est le sens du discours des sujets, qui est investigué. L’outil psychanalytique évalue effectivement la façon dont les sujets s’expriment, et ce sont des juges naïfs (à l’égard de l’étude et de la psychanalyse) qui évaluent leur discours. Nos résultats mettent en évidence que les personnes dépendantes manifestent une tendance à l’impulsivité de façon générale. Mais, lorsque leur objet d’addiction est en place de support attentionnel, les sujets démontrent une augmentation significative de leurs performances et de l’amplitude de la P3, signe d’un investissement attentionnel. Les résultats des associations libres révèlent que la forme du discours des fumeurs est évaluée comme plus transgressive (comparativement aux non-fumeurs). Enfin, on retrouve une corrélation entre les indices psychiques (la transgression) et neurophysiologiques (la latence de la NoGo-N2). En conclusion, il semble que l’addiction dépasse la simple réalité pharmacologique de l’effet du toxique puisqu’il est repéré ici que l’effet de stimulant cognitif (manifeste par l’amélioration des performances) est induit par la simple représentation de la cigarette et non par la consommation de celle-ci. Ensuite, au regard de notre proposition épistémologique, nous semblons avoir réussi, sur base d’une lecture rapprochée des séminaires de Lacan, à construire un outil qui distingue de façon cohérente, consistante et valide une dimension pulsionnelle d’une dimension affective (valencée) dans ce qui peut s’entendre. Grâce à cet outil, nous avons trouvé des corrélations entre certains de ces marqueurs psychiques et certains paramètres physiologiques - les paramètres corrélant étant précisément des plus probants et la corrélation s’avérant être dans le sens prédit par notre construction hypothétique. Sur ce 'succès’, nous osons une conclusion épistémologique plus large qui propose que si l’univers du représentationnel, c'est-à-dire, du mental, est bien accroché au niveau de repères physiologiques, ceci n’est démontrable sur un plan mental que si l’on se borne à la forme des contenus mentaux – et, qui plus est, et de façon spéculative, en évitant toute hérméneutique au niveau des contenus mentaux. / Doctorat en Sciences psychologiques et de l'éducation / info:eu-repo/semantics/nonPublished

The default mode network (DMN) is a highly cited neural network whose functional roles are not well understood. Until recently, event related fMRI experiments used to study the DMN could only be conducted in an open-loop format. The purpose of this study was to demonstrate the potential statistical advantages of real-time fMRI studies to conduct closed-loop experiments to directly test putative DMN functions. Using both fMRI simulations and large archival datasets, we demonstrate that open-loop designs are less statistically powerful than closed-loop experiments that can trigger stimuli at controlled levels of brain activity. When simulating event scheduling on resting state data, DMN levels were normally distributed, but the event timing proved to be ineffective in capturing the highest and lowest DMN values on average across subjects. Statistical differences in DMN levels collected by the Human Connectome Project-Aging (HCP-A) during a Go/NoGo task were also reported, along with the network's distributional effects across subjects. When examining DMN levels in 136 subjects more prone to commission errors the mean DMN levels were reported to be higher during and prior to incorrect NoGo responses. Exploring DMN levels in these same individuals reacting to a Go task also revealed differing measurement patterns when compared to all 711 subjects in the study. Additionally, the distribution of total DMN levels across all participants, as well as during a Go or NoGo trial, showed a shift in the mean towards deactivation. Furthermore, the peak at this location was greater and revealed that increased sampling occurred at the mean and under sampling at the tails. Overall, the cumulative findings in this study were successful in providing statistical arguments to support propositions for more powerful closed-loop experimentation in fMRI. / Master of Science / Activity in a neural network is observed through the use of functional MRI (fMRI) by tracking higher levels of oxygenated blood to that region when active and lower quantities when inactive. Neural networks vary in their responsibilities, thus fMRI tasks are designed to trigger a response based on the functional role of the network. This can be exemplified by studying the blood flow to default mode network (DMN), a network responsible for mind wandering, during a task that requires focus. Researchers can then correlate moments of high activity, which indicates a greater degree of mind wandering, or low activity to a correct or incorrect response to the task. Unfortunately, the timing in which a task is presented to the participant is predetermined prior to the subject entering the MRI making it difficult to capture a correct or incorrect response at the precise moment of activation or deactivation. This concept is known as open-loop and often collects data at moments of neutral activity, neither high nor low. In contrast, a closed-loop design allows a researcher to monitor the DMN's activation levels in real time and present the task at a desired time. This provides more useful data to the experimenter as all recorded responses to the task correlate with exact moments of high and low activation. This makes claims about the neural network's role statistically more powerful as there is a greater quantity of data at these moments rather than during a neutral activation state. The purpose of this thesis is to provide statistical arguments that support propositions for more powerful closed-loop experimentation in fMRI.

O trabalho objetivou analisar os fatores que influenciam a mobilização da atenção automática visual. Nas tarefas diárias, o Sistema Nervoso Central seleciona os estímulos mais relevantes para as tarefas. Para entender o quê influencia a mobilização atencional, conduzimos três experimentos com análise do tempo de reação a um estímulo vai em relação a um não-vai em voluntários humanos. Utilizamos um estímulo abrupto anterior ao aparecimento dos estímulos alvos para capturar a atenção automática na mesma posição ou na oposta ao aparecimento do estímulo alvo, para medir o efeito atencional. No 1º experimento, analisamos a influência da semelhança dos estímulos negativo e positivo e obtivemos o efeito atencional. Em seguida, pesquisamos a influência da semelhança do estímulo precedente com a do estímulo positivo e não encontramos evidências a respeito. Por último, verificamos como a estratégia atencional influencia no efeito atencional, mas não houve tal efeito. Concluímos que o fator crítico para a mobilização eficaz da atenção automática é a discriminabilidade entre os estímulos vai e não-vai. / This project investigated the important factors to mobilize the visual automatic attention. During our day, the Central Nervous System selects the most important stimulus to have a good performance in a task. For understanding which factors influence the attentional mobilization, we did three experiments analyzing the reaction time to a go stimuli comparing to a no go stimuli with human volunteers. We used an onset stimulus appearing before the go and no go stimuli at the same or at the opposite positions for having the attentional effect. At the first experiment, we researched the influence of go and no-go similarities and there was the attentional effect. Then, we investigated if the similarity between positive targets and cue is the critical factor but we didn\'t find the attentional effect. Finally, we checked the possibility of attentional effect to the CR by inducing the adoption of VL´s attentional set by volunteers, but there wasn\'t no effect. We concluded that the most important factor to an efficient mobilization of the automatic attention is the discriminability between the go and no-go stimuli.

La maladie de Parkinson est une maladie neurodégénérative secondaire à la mort des neurones dopaminergiques, entraînant un dysfonctionnement des ganglions de la base (GB), ensemble de noyaux sous corticaux impliqués dans le contrôle de la motricité. Les symptômes moteurs sont améliorés par le traitement dopaminergique et par la stimulation cérébrale profonde (SCP) du noyau subthalamique (NST). Il a été montré que le changement d’activité bêta est corrélé avec l’amélioration motrice des symptômes de bradykinésie et rigidité. L’hypothèse serait que les oscillations bêta pourraient être un physiomarqueur spécifique des symptômes moteurs de la MP. L’objectif de cette thèse est de comprendre l’activité du NST et de trouver un physiomarqueur de la MP : au repos et pendant un paradigme Go/Nogo.Dans une première partie, pour 55 patients, nous avons modélisé la puissance avec un modèle linéaire à effets mixtes dans six bandes de fréquences selon la position des électrodes, la présence de complications liées au traitement dopaminergique, de la sévérité des symptômes, et du changement de ces symptômes suite à la prise du traitement dopaminergique. Le changement le plus important entre OFF- et ON-DOPA est observé dans la bande low-bêta. Cependant, nous n’avons pas trouvé de corrélation entre la sévérité de la bradykinésie, rigidité, ou du score axial avec l’activité low-bêta. Mais, nous avons trouvé que la sévérité de la rigidité était associée aux fréquences supérieures à 20Hz. Nous avons également trouvé une corrélation positive entre la sévérité du tremblement dans toutes les bandes de fréquences, qui est très importante pour la bande thêta. Etonnement, nous avons trouvé que les complications liées au traitement dopaminergique pouvaient induire des informations dans toutes les bandes. Cet effet est très important pour la bande thêta. Nos résultats au repos suggèrent que l’activité bêta n’est pas le physiomarqueur idéal de la MP.Pendant le paradigme Go/Nogo, pour 15 patients, nous avons modélisé la puissance avec un modèle linéaire à effets mixtes pour toutes les fréquences selon la position des électrodes, la sévérité des symptômes, les données comportementales et cinétiques. Nous avons trouvé une spécificité temporelle et spatiale des activités du NST au cours du paradigme. Nos résultats montrent que le NST est impliqué dans le contrôle des différentes étapes du mouvement volontaire du membre supérieur et que le défaut de dopamine dans le circuit sensorimoteur des GB génère une série de changements oscillatoires au sein du NST lors du mouvement. Cependant, l'activité thêta est apparue comme une activité caractéristique en OFF-DOPA fortement corrélée aux paramètres comportementaux et cinétiques. Cette activité pourrait être le physiomarqueur de la MP pendant l'exécution d'un mouvement, son augmentation pourrait induire une réponse motrice et un mouvement rapide. / The Parkinson's disease is a secondary neurodegenerative disease in the death of the dopaminergic neurons, pulling a dysfunction of the ganglions of the base (GB), the set pits under cortical implied in the control of the motricity...

O trabalho objetivou analisar os fatores que influenciam a mobilização da atenção automática visual. Nas tarefas diárias, o Sistema Nervoso Central seleciona os estímulos mais relevantes para as tarefas. Para entender o quê influencia a mobilização atencional, conduzimos três experimentos com análise do tempo de reação a um estímulo vai em relação a um não-vai em voluntários humanos. Utilizamos um estímulo abrupto anterior ao aparecimento dos estímulos alvos para capturar a atenção automática na mesma posição ou na oposta ao aparecimento do estímulo alvo, para medir o efeito atencional. No 1º experimento, analisamos a influência da semelhança dos estímulos negativo e positivo e obtivemos o efeito atencional. Em seguida, pesquisamos a influência da semelhança do estímulo precedente com a do estímulo positivo e não encontramos evidências a respeito. Por último, verificamos como a estratégia atencional influencia no efeito atencional, mas não houve tal efeito. Concluímos que o fator crítico para a mobilização eficaz da atenção automática é a discriminabilidade entre os estímulos vai e não-vai. / This project investigated the important factors to mobilize the visual automatic attention. During our day, the Central Nervous System selects the most important stimulus to have a good performance in a task. For understanding which factors influence the attentional mobilization, we did three experiments analyzing the reaction time to a go stimuli comparing to a no go stimuli with human volunteers. We used an onset stimulus appearing before the go and no go stimuli at the same or at the opposite positions for having the attentional effect. At the first experiment, we researched the influence of go and no-go similarities and there was the attentional effect. Then, we investigated if the similarity between positive targets and cue is the critical factor but we didn\'t find the attentional effect. Finally, we checked the possibility of attentional effect to the CR by inducing the adoption of VL´s attentional set by volunteers, but there wasn\'t no effect. We concluded that the most important factor to an efficient mobilization of the automatic attention is the discriminability between the go and no-go stimuli.

Introdução: o Diabetes Mellitus é uma epidemia mundial de incidência crescente e alta morbi-mortalidade. Apesar de a neuropatia diabética ser a complicação neurológica mais comum, é crescente o conhecimento de que existe um acometimento do sistema nervoso central, notadamente no que concerne às alterações cognitivas. Objetivos: investigar, por meio de duas tarefas cognitivas objetivas, simples, rápidas, de baixo custo e de fácil aplicação, diferenças entre pacientes com Diabetes Mellitus Tipo 1 (DM1) e controles quanto a medidas de atenção e impulsividade, componentes-chave das funções executivas tradicionalmente avaliados por questionários subjetivos, longos, de difícil reprodutibilidade e que exigem psicólogos treinados; correlacionar as diferenças encontradas com características clínicas; explorar as correlações entre as duas tarefas. Métodos: Foram comparados os desempenhos de 20 pacientes com DM1 e 20 controles, de ambos os sexos, com idades entre 12 e 15 anos, utilizando a tarefa Agir-Não Agir e uma tarefa de Labirintos, e verificadas correlações entre eles. Resultados: o grupo DM1 teve mais respostas antecipatórias (RA) na tarefa Agir-Não Agir (p<0,05) e fez mais mudanças de trajetória nos Labirintos (p <0,01). Houve correlação entre hipoglicemias não-graves e RA (p=0,01), e entre hipoglicemias graves e número de toques nas paredes dos labirintos (p <0,05). HbA1c> 9% correlacionou-se com um maior número de becos sem saída nos labirintos (p <0,05). Os parâmetros mostraram-se coerentes dentro de cada tarefa e entre elas. Conclusões: Encontramos indicadores de desatenção e impulsividade coexistindo no DM1, o primeiro estando mais relacionado à hiperglicemia, e o último à hipoglicemia. Investigações adicionais são necessárias para estudar o declínio cognitivo associado ao diabetes por meio de avaliações mais objetivas, e avaliar a confiabilidade e as propriedades psicométricas das tarefas aqui propostas. / Background : Diabetes Mellitus is a worldwide epidemic of increasing incidence and high morbidity and mortality. Although diabetic neuropathy is the most common neurological complication, the knowledge that there is an involvement of the central nervous system is increasing, especially in relation to cognitive changes. Aims: To investigate with two simple, inexpensive, rapid, objective and easy-to-apply tasks, differences between patients with Type 1 Diabetes Mellitus (T1DM) and controls in outcome measures of attention and impulsivity, key-executive function components traditionally assessed by subjective and long questionnaires of difficult reproducibility that require trained psychologists; to correlate the alterations with clinical characteristics; to explore correlations between the tasks. Methods: We compared the scores of 20 T1DM to 20 controls, both sexes, aged 12 to 15 years, using a Go-NoGo and a Maze task, and verified correlations between them. Results: T1DM group had more anticipatory answers (AA) in Go-NoGo task (p<0,05) and made more direction changes in Mazes (p<0,01). There was correlation between non-severe hypoglycaemias and AA (p=0,01), and between severe hypoglycaemias and number of touches in Mazes’ walls (p<0,05). HbA1c>9% correlated to a greater number of alleys in Mazes (p<0,05). The tasks’ parameters were coherent among each task and between them. Conclusions: We found indicators of inattention and impulsivity coexisting in T1DM, the first more related to hyperglycaemia and the later to hypoglycemia. Further research is needed to study diabetes-associated cognitive decline with more objective parameters and evaluate the reliability and psychometric properties of the tasks herein proposed. / Dissertação (Mestrado)