The immune system has been suggested as crucial in brain and psychological functioning. More precisely, immune markers reflecting immune system activity are important for psychological and mental health, as evident by their role in the physiopathology of depression and in the impairment of executive functions. Frontal alpha asymmetry (FAA), an electroencephalographic marker of brain function, has also been linked to such psychopathology and is thought to reflect psychological processes underlying approach- versus withdrawal-related motivation and higher-order inhibitory control. Only a few studies have linked FAA to immune markers but notably found a negative association between IL-6, a pleiotropic proinflammatory cytokine, and FAA. The aim of the present work is thus to study the relationship between various immune markers (including pro-inflammatory cytokines and IL-6) and FAA. 35 healthy young male participants underwent a resting EEG recording and blood sampling from which immune markers were measured. The results did not suggest an association between IL-6 and FAA. No other immune markers were either suggested to be associated to FAA. The complexity of the immune system (e.g., effect of cytokines) is underlined and may explain the results. Despite such results, the implication of true negative correlations between FAA and circulating immune markers, as suggested in previous studies, is discussed in the light of the theoretical models of FAA.

Executive control is a vital cognitive function that facilitates the focussing and shifting of attention, planning and working towards a goal, ignoring distractions, and flexibly responding to novel situations. Disruptions to executive control are seen in many psychiatric and neurodegenerative disorders, as well as healthy ageing, which can be profoundly detrimental. Despite having many effective and well-validated methodologies for detecting and quantifying these deficits, there are very few treatments — pharmacological or otherwise — for ameliorating executive dysfunction. This lack of progress can partly be blamed on difficulties associated with identifying drugs that enhance cognition in preclinical research. The work in this thesis aimed to expand our understanding of executive dysfunction — as well as the tasks that measure it — in rats. In results presented in chapter three, middle-aged rats demonstrated impaired reversal learning on the standard attentional set-shifting task, but this was treatable with a novel drug targeting the N-methyl-D-aspartate receptor. The age impairments seen in this experiment were similar to those previously found in young rats with orbital prefrontal cortex (OFC) lesions. The results of chapter four expanded on this similarity to show that, along with reversal deficits, young OFC-lesioned rats are impaired at forming attentional sets when tested on a modified task. In chapter five, another modified set-shifting task revealed that middle-aged rats also suffer from impaired set-formation, but their reversal learning impairments only manifest before attentional set has been formed — not after. Finally, in chapter six, the putative cognitive enhancer modafinil was found to exacerbate middle-aged rats' reversal learning deficit, but it also enhanced their subsequent ability to form attentional set. These experiments reveal that modifying the rat attentional set-shifting task can sometimes make it a more effective tool for testing cognitive enhancers in preclinical settings.

La maladie de Parkinson (MP) est la deuxième maladie dégénérative la plus répandue au Canada. Elle se caractérise par des symptômes moteurs importants tels le tremblement de repos, la rigidité musculaire, l’instabilité posturale, la lenteur dans les mouvements ainsi que par des symptômes non moteurs, notamment une diminution du fonctionnement cognitif. Conséquemment, la nature hétérogène des symptômes de la MP dirige bien souvent l’individu atteint vers une sédentarité physique et mentale involontaire. Les traitements pharmacologiques et neurochirurgicaux demeurent les approches thérapeutiques majoritairement choisies. Toutefois, de plus en plus d’études visant à examiner les impacts de l’exercice physique aérobique (EPA) ont démontré des bénéfices de ce traitement non pharmaceutique, entre autres, en améliorant les symptômes moteurs de la maladie. Néanmoins, l’effet de l’exercice sur la cognition et l’apprentissage moteur à travers la MP est encore méconnu. Ainsi, ce projet de thèse vise à étudier les changements cognitifs et moteurs suite à un entrainement cardiovasculaire. Une première étude visait à mesurer les changements comportementaux au niveau de la capacité aérobique, des fonctions cognitives dites exécutives et de l’apprentissage procédural moteur suite à l’EPA. Une deuxième étude utilisant l’imagerie par résonance magnétique fonctionnelle (IRMf) permettait ensuite d’identifier les corrélats neuronaux associés à l’effet de l’EPA sur l’apprentissage moteur. 20 participants en santé et 19 atteintes de la MP, âgées entre 40-80 ans, ont participé à un programme d’entrainement de 3 mois (3 fois/semaine) à une intensité élevée, débutant à 20 minutes (+5 minutes/semaine) pour atteindre 40 minutes d’EPA. Le niveau d’intensité de base a été prescrit selon la capacité aérobique initiale du participant en réponse au test à l’effort effectué (pré et post entraînement). Plusieurs mesures d’évaluation physiques (VO2peak, pression artérielle, fréquence cardiaque) et neuropsychologiques (« Stroop, trail making test » (TMT)) ont été prises en début et à la fin de l’entraînement. De plus, des sessions d’acquisition de données cérébrales fonctionnelles grâce à l’IRMf ont été administrées durant la passation d’une tâche d’apprentissage moteur implicite (tache : « Serial Reaction Time Task »(SRT)). Les résultats ont montré que l’entraînement en EPA fut efficace car une amélioration significative de la capacité aérobique fut observée chez tous les participants. Au niveau comportemental, l’EPA a eu pour effet d’améliorer les capacités d’inhibition (Stroop) et d’apprentissage moteur (SRT), mais pas celle associée à la flexibilité mentale (TMT). Pour leur part, les données de neuroimagerie ont révélé une augmentation de l’activité fonctionnelle liée à l’amélioration de l’apprentissage moteur au niveau de l’hippocampe, du striatum et du cervelet, et ce en comparaison avec les sujets contrôles. De plus, les changements fonctionnels chez les individus atteints de la MP étaient corrélés au changement de la capacité aérobique : une relation positive fut liée à l’augmentation de l’activité de l’hippocampe et du striatum, tandis qu’une relation négative fut observée au niveau du cervelet. Ce projet est l’un des premiers à mettre en lumière l’impact clinique d’un traitement non pharmaceutique visant à améliorer la nature motrice et cognitive des symptômes de la MP, ainsi que de proposer les mécanismes neurofonctionnels pouvant expliquer l’amélioration observés au niveau de l’apprentissage suivant l’entrainement en EPA. Ainsi, nous croyons que les résultats de cette étude serviront les milieux cliniques et la population de patients atteints de la maladie de Parkinson en proposant une solution thérapeutique efficace et économique afin d’améliorer la qualité de vie de ces derniers. / Parkinson’s disease (PD) is the second most common neurodegenerative disorder in Canada. It is mainly characterized by important motor symptoms such as slow movement, tremor, rigidity and problems with locomotion, but non-motor symptoms (NMS) such as cognitive dysfunctions are also present early in the disease. Inadvertently, the heterogeneous nature of PD’s symptoms may lead to an unintentional sedentary behaviour both at the physical and mental level. To date, the most common forms of PD treatments remain pharmacological and neurosurgical in nature. Most recently, however, studies have demonstrated benefits of aerobic exercise training (AET) as a non-pharmaceutical treatment with significant effects on PD’s motor symptoms. Nevertheless, the effects of exercise on cognitive and motor learning function in PD remain unknown. Thus, this thesis project aims at studying cognitive and motor changes following AET. Most specifically, the first study intended to assess behavioural changes related to aerobic capacity, cognitive (executive) functions and procedural learning following three months of AET. The second article used functional magnetic resonance imaging (fMRI) to identify the neural correlates associated with the effect of AET on motor learning. Twenty healthy controls (HC) and 19 early PD individuals, aged 40-80 years old, participated in a supervised high intensity stationary recumbent bike training program (3 times/week; 12 weeks). Exercise prescription started at 20 minutes (+5 minutes/week up to 40 minutes) based on participants’ maximal volume of oxygen uptake (pre and post training). Several physical (VO2peak, blood pressure, heart rate) and cognitive (Stroop and Trail making tests (TMT)) measures were used pre and post AET. Importantly, participants’ procedural learning skill (implicit motor learning) was evaluated using a version of the Serial Reaction Time Task (SRT) during the acquisition of functional neuroimaging data. AET program was effective as indicated by a significant improvement in aerobic capacity in all participants. At the behavioural level, AET improved inhibition (Stroop) and motor learning (SRT), but not flexibility (TMT). Brain imaging data revealed pre-post MSL-related increases in functional activity in the hippocampus, striatum and cerebellum in PD patients as compared to controls. Importantly, functional brain changes in PD individuals correlated with changes in aerobic capacity: a positive relationship was found with increased activity in the hippocampus and striatum, while a negative relationship was observed with the cerebellar activity. This project is one of the first to elucidate the clinical impact of such non-pharmaceutical treatment targeting motor and non-motor aspects of PD. Accordingly, it is believed that the results will be of use for clinical settings and for the population of patients with PD, as they give evidence in favour of an efficient and economical therapeutic solution for PD.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

De nombreuses études ont montré une modification de la perception de la douleur au cours du vieillissement. Cette modification s’exprime principalement par une diminution du seuil de la douleur aiguë et une augmentation de la prévalence de douleurs chroniques. Parallèlement, le vieillissement provoque des altérations cérébrales importantes, notamment dans les réseaux frontaux. Dans ce travail de thèse, nous avons étudié les mécanismes centraux, notamment les fonctions des réseaux frontaux sur la perception et la modulation de la douleur chez la personne âgée. Les résultats des expériences 1 à 3 suggèrent une forte corrélation positive entre l’altération des fonctions exécutives et le déclin de la modulation cognitive de la douleur et de la résistance à la douleur tonique. Dans l’expérience 4, nos résultats montrent que les scores aux tests mesurant les fonctions émotionnelles (e.g. la reconnaissance des émotions) sont corrélés au ressenti de la douleur. Cela pourrait indiquer un déficit chez les personnes âgées de la composante émotionnelle qui entre en jeu dans la perception de la douleur. / Age-related changes in pain perception have been widely reported in the literature, showing a reduced acute pain perception and an increased prevalence of chronic pain. Ageing also results in considerable alterations in brain structures and functions, particularly in frontal networks. In this thesis, we explored the underlying central mechanisms, especially the role of frontal functions in the age-related alterations in pain perception. Results of experiments 1-3 demonstrated a strong positive correlation between the age-related alterations in executive function and the decline in pain tolerance and cognitive pain modulation. In experiment 4 we observed that the emotional function measured by a test of emotions recognition was correlated to the verbal expression of perceived pain, indicating that the reduced pain expression in the elderly may result from the deficient responses to emotion.

No modelo dos multicomponentes da memória de trabalho o problema do armazenamento da ordem serial de eventos visuais e espaciais ainda é muito discutido. A literatura sugere que recursos do executivo central (o sistema de controle atencional da memória de trabalho) são utilizados para manter a representação da posição serial dos estímulos visuais e espaciais na memória. Mais precisamente, é proposto que a função executiva de atualização de informações esteja envolvida com este processo. Esta função promoveria a modificação contínua da representação mental conforme a entrada de novas informações no sistema cognitivo. Entretanto, não está esclarecido se ocorre uma dissociação visual e espacial no uso de recursos da função executiva de atualização de informações para o registro da ordem serial. O objetivo do presente estudo foi verificar o envolvimento da função executiva de atualização da informação na memória para a ordem de eventos visuais e espaciais. Os participantes foram estudantes universitários (n = 71) que realizaram as tarefas de memória delineadas segundo o paradigma de tarefas duplas. Neste procedimento as tarefas primárias de memória visual e espacial foram combinadas a tarefas secundárias executivas de tempo de reação de escolha (CRT) e tarefas que exigiam recursos de atualização da informação (tarefa de tempo de reação de escolha para um item anterior CRT-1). Na tarefa CRT o participante deveria julgar dois tons auditivos como sendo de alta ou baixa frequência. Na tarefa CRT-1 esta resposta deveria ser atrasada em um item, ou seja, a resposta ao estímulo n só deveria ser dada quando o estímulo n + 1 fosse apresentado. As tarefas secundárias eram realizadas durante a apresentação dos estímulos e no intervalo de retenção das tarefas primárias. No primeiro experimento a capacidade máxima de armazenamento espacial e visual (span) de cada participante foi estabelecida em sessão pré-teste, e no segundo experimento o participante memorizou sequências de três a sete itens. Os resultados mostraram que, de modo geral, o desempenho dos participantes nas tarefas primárias foi prejudicado mediante a interferência na função de atualização de informações. As semelhanças entre a memória serial visual e a memória serial espacial foram: curvas de posição serial caracterizadas por primazia e recência; predominância de erros de transposição de deslocamento em um item da posição correta; efeito prejudicial do aumento do tamanho da sequência; queda do desempenho quando recursos executivos são reduzidos, principalmente os designados a sustentar a função executiva de atualização da informação. As diferenças entre os dois tipos de representação serial em geral foram: menor capacidade e precisão na representação de itens na memória visual em comparação à espacial; a memória visual é mais susceptível ao aumento da quantidade de itens para retenção e para este tipo de armazenamento não há uma diferenciação clara entre os efeitos dos dois tipos de interferência executiva (CRT e CRT-1), como pôde ser determinado para a tarefa espacial. Conclui-se que recursos executivos de atualização da informação participam dos mecanismos envolvidos com o registro da ordem serial dos eventos visuais e espaciais de maneira integrada aos recursos específicos do armazenador visuoespacial. Sugere-se que a memória visual conta com um mecanismo de registro da ordem serial semelhante à memória espacial, sendo que as diferenças entre os dois padrões de desempenho são atribuídas às especificidades no registro da identidade dos itens, e não na manutenção da ordem serial dos mesmos. Implicações para a compreensão da interação funcional entre recursos de armazenamento e processamento da informação na memória de trabalho são discutidos. / In the multicomponent model of working memory is still unclear how the serial order of visual and spatial events is retained in memory. The literature suggests that the central executive resources (the attentional control system of working memory) are used to maintain the representation of serial position. More precisely, it is proposed that the executive function of updating information is involved with this process. This function makes continuous modification of mental representation to accommodate new information in the cognitive system. However, until now had not yet been determined whether there is a visual-spatial dissociation in use of executive function of updating information for the registration of serial order. The aim of this study was to investigate the involvement of the executive function of updating information in memory for the order of visual and spatial events. Participants were undergraduate students (n = 71) who performed memory tasks designed under the paradigm of dual-tasks. In this procedure the primary tasks of visual and spatial memory were combined with secondary executive tasks of choice reaction time (CRT) and tasks that occupied resources required to update the information (one-back choice reaction time CRT-1). In the CRT task the participant should judge two auditory tones as high or low frequency. In CRT-1 task this response should be delayed in one item, that is, the response to the n stimulus should only be given when the n + 1 stimulus was presented. The secondary tasks were performed during the presentation of the stimuli and the retention interval of the primary tasks. In the first experiment the capacity (span) to retain spatial and visual information was established in pre-test session, and in the second experiment the participants memorized sequences of three to seven items. The results showed that, overall, participants\' performance on primary tasks was impaired by interference on the updating information. The similarities between visual and spatial serial memory were: primacy and recency in serial position curves; most frequent serial position error of transposition in one item; detrimental effect of increasing the size of the sequence, performance impaired by the interference in the executive resources, especially those designed to support the executive function of updating information. The differences between the two types of serial representation, in general, were: smaller capacity and precision in the representation of visual items as compared to the spatial characteristics; the vulnerability of visual memory to the increasing the amount of items is bigger than in spatial memory, and for visual memory there is not a clear differentiation between the effects of two types of executive interference (CRT and CRT-1) as could be determined for the spatial task. We conclude that executive resources of updating information are part of the mechanisms involved in the registration of the serial order of visual and spatial events, and they work in an integrated manner to specific visuospatial resources. The data suggests that visual memory has a mechanism for registration of serial order like spatial memory, and the differences between the two patterns of performance are attributed to the maintenance of identity of the items, and not the maintenance of serial order. Implications for understanding the functional interaction between storage resources and processing of information in working memory are discussed.

Patienten mit Zwangserkrankung (OCD) weisen selektive Defizite in der Verarbeitung komplexer visueller Informationen sowie im Bereich der Exekutivfunktionen auf, welche sich teilweise auch bei depressiv erkrankten Patienten finden. Das Ziel der Untersuchung bestand darin, kognitive Defizite bei OCD-Patienten zu identifizieren, die ein spezifisches Korrelat der Zwangssymptomatik in Abgrenzung zu Patienten mit unipolarer Depression (MD) darstellen. Vierzig OCD-Patienten, 20 MD-Patienten sowie 40 gesunde Kontrollprobanden wurden hinsichtlich sieben kognitiver Domänen neuropsychologisch untersucht. Innerhalb der OCD-Stichprobe wurden die Leistungen von hoch- und niedrigdepressiven OCD-Patienten nach BDI-Mediansplit (MedianBDI = 15,5) sowie von Patienten mit vs. ohne familiäre Häufung der Erkrankung einander gegenübergestellt. Die OCD-Patienten zeigten Beeinträchtigungen gegenüber Gesunden in allen untersuchten Bereichen bis auf die Domäne „Verbales Gedächtnis“. Die Defizite in den Domänen „Visuelle Organisation“ und „Problemlösen/Arbeitsgedächtnis“ erwiesen sich spezifische Korrelate der Zwangssymptomatik. Die MD-Patienten wiesen ein mit den OCD-Patienten überlappendes Defizit in der Domäne „Verbale Flüssigkeit“ auf. In der OCD-Gruppe korrelierte die Schwere der Zwangsgedanken negativ mit der Domäne „Visuelle Organisation“. Das Ersterkrankungsalter korrelierte negativ mit der Domäne „Visuomotorik/Aufmerksamkeitswechsel“. Es bestand kein bedeutsamer Einfluss der depressiven Begleitsymptomatik sowie der familiären Häufung von OCD auf die kognitiven Leistungen. Anhand dieser Arbeit wurde belegt, dass es sich bei den Defiziten der OCD-Patienten hinsichtlich der visuellen Gestalterfassung sowie der mentalen Manipulation komplexer visueller Information um spezifische Merkmale der Zwangserkrankung in Abgrenzung zu milden Formen unipolarer Depression handelt. Eine leichte depressive Begleitsymptomatik mindert die kognitiven Leistungen von OCD-Patienten nicht zusätzlich. / Patients suffering from Obsessive Compulsive Disorder (OCD) show selective deficits both in the processing of complex visual information and regarding executive functions. Patients with Major Depression (MD) were found to have, in parts, similar impairments. The aim of the present study was to identify those cognitive deficits in OCD patients which are a correlate specific to OCD, as opposed to MD patients. We also looked at the influence of the following factors on the cognitive functions of OCD patients: concomitant depression, severity of the disorder, age at onset, and the occurrence of OCD symptoms among immediate family. Forty OCD patients, 20 MD patients, and 40 healthy controls underwent neuropsychological assessment and were compared across seven cognitive domains. For the OCD sample, results of highly and slightly depressive OCD patients, according to BDI median split (medianBDI = 15.5) were compared, as were those of patients with and without a family history of the disorder. OCD patients showed impairments across all domains, not including “Verbal Memory”. The deficits in the domains “Visual Organisation” and “Problem Solving/Working Memory” were found to be specific correlates of obsessive-compulsive symptoms. MD patients had a deficit in “Verbal Fluency” similar to that of OCD patients. Within the OCD group, we found a negative correlation between the current severity of obsessive thoughts and the domain “Visual Organisation”. Age at onset correlated negatively with “Visual Motor Speed/Attentional Set-Shifting”. Neither concomitant depression nor a family history of OCD symptoms influenced cognitive performance significantly. The study proved that the deficits of OCD patients concerning visual organisation and mental manipulation of complex, visually coded information are features specific to this disorder, in delimitation from mild forms of major depression. Concomitant mild forms of depression do not further impair cognitive functions in OCD-patients.

Les séquelles neuropsychologiques associées aux tumeurs cérébrales pédiatriques représentent un enjeu de santé publique. Les troubles des fonctions exécutives sont désormais avérés chez ces enfants mais la nature des processus perturbés, les modalités d'évaluation à préconiser et l'impact des variables démographiques/médicales liées à la maladie restent méconnus. L'objectif de cette thèse était de mieux comprendre le profil de perturbation des différents processus exécutifs dans ce contexte clinique, en confrontant des mesures basées sur la performance et des indicateurs de vie quotidienne (dans le contexte familial et scolaire). Dans cette perspective, nous avons 1) analysé le profil exécutif de 171 enfants d’âge scolaire atteints d'une tumeur cérébrale à la BRIEF (Inventaire d'évaluation comportementale des fonctions exécutives) et 2) étudié la convergence de ces indicateurs avec des mesures basées sur la performance adaptées en français auprès de 27 patients appariés à des enfants sains. L’influence des variables cliniques sur les profils exécutifs a été examinée. Des difficultés exécutives étendues mais variables ont été identifiées dans le quotidien des patients (tous types histologiques et localisations) au domicile et à l’école, avec par ailleurs des difficultés accrues rapportées par les parents en cas d’irradiation à un âge précoce. Des perturbations du contrôle exécutifs ont confirmées dans les mesures directes, dont la convergence avec les questionnaires apparait cependant limitée. Sur la base de ces résultats, sont discutés les apports respectifs de ces deux types d’outils pour appréhender la problématique exécutive dans le cadre des tumeurs pédiatriques. / Neuropsychological sequelae associated with pediatric brain tumors represent a major public health issue.Disorders of executive functions have been identified among these children, but the nature of the impaired processes, recommended evaluation modalities and the impact of demographic and medical variables related to the disease remain unclear. The aim of this thesis was to get a broader understanding of the disturbance profile of the different executive processes in this disease context, comparing performance-based measures and daily life indicators (in both the school and home environment). From this perspective, we have 1) analyzed the executive profile of 171 school age children with a brain tumor in the BRIEF (Behavior Rating Inventory of Executive Function) and 2) examined the association of these indicators with performance-based measures adapted in French in 27 patients matched to healthy children. The influence of clinical variables on the executive profiles was discussed. Broad and variable executive difficulties have been identified in patients’ everyday life (all tumor types and locations) at home as well as school, with also increased difficulties reported by parents in the case of radiation therapy at an early age. Disturbances of executive control are confirmed in direct measures, whose convergence with the questionnaires appears however limited. Based on these results, respective contributions of these two types of tools are discussed in order to understand the executive issue in pediatric brain tumor survivors.

Made available in DSpace on 2016-03-22T17:27:01Z (GMT). No. of bitstreams: 1 lisandra.pdf: 1280734 bytes, checksum: 77954c73d726cb9b0c0c8d2886cffd72 (MD5) Previous issue date: 2013-03-15 / The bilingual experience of code-switching using another language during speech production demands a greater executive and attentional control than that required from monolinguals, and seems to spread to other nonlinguistic cognitive domains. Studies on bilingualism have shown that bilinguals tend to outperform monolinguals on nonlinguistic interference tasks measuring different executive functions (EFs) (mental processes in charge of regulating, controlling and managing other cognitive processes, such as inhibition, attention, problem solving, etc.). However, recent research has shown that bilinguals tend to show a more robust advantage in overall reaction times (RTs), rather than an advantage on the magnitude of the interference effect. Irrespective of nature, the so-called bilingual advantage has been found in different age groups, among different types of bilinguals (e.g., Bialystok et al., 2004; Bialystok et al., 2005; Costa et al., 2008; Martin-Rhee & Bialystok, 2008), but sometimes, no bilingual advantage is actually found. The present study aims at replicating some of the experiments conducted previously with other populations of bilingual and monolingual participants regarding the EFs inhibitory control (Bialystok et al., 2004) and attentional networks (Costa et al., 2008). For that, I interviewed and tested 40 middle-aged businesspeople (20 bilinguals mean age 48.1 and 20 monolinguals mean age 47.2) in two nonlinguistic interference tasks: the Simon task (Simon & Wolf, 1963), and the Attentional Network Task (ANT) (Fan et al., 2002). Businesspeople are naturally faced with strong cognitive demands in their daily lives, constantly having to solve problems by making administrative and financial decisions that involve a lot of responsibility and a lot of people, regardless of product or service being sold or offered by the company. Thus, their professional activity could strengthen their inhibitory control and problem solving skills, which could compete with the cognitive advantages brought out by bilingualism. For this reason, I also included a control group with a different professional activity, consisting of 38 middle-aged teachers/professors (19 bilinguals mean age 46.6 and 19 monolinguals mean age 46.2), to be compared to the businesspeople in the Simon task. It is important to underscore the fact that no previous work has addressed such populations in these regards. Furthermore, I perceived that there are not enough studies on the effects of bilingualism on middle-aged adults regarding these EFs, as compared to the number of studies and findings on the bilingual advantage among other age groups. The results obtained with the businesspeople groups in both tasks showed no bilingual advantage in the interference effect or in overall RTs. However, I cannot assign the absence of a bilingual advantage to the variable Profession as a competitor with bilingualism, for the control group also presented equivalent performances across the mono and bilingual groups in the Simon task / A experiência bilíngue de troca de código o uso de uma outra língua no decorrer de uma conversação exige um maior controle executivo e atencional do que o exigido de monolíngues, e parece espraiar-se para outros domínios cognitivos não linguísticos. Os estudos sobre bilinguismo têm mostrado que bilíngues tendem a ter um melhor desempenho do que monolíngues em tarefas de interferência não linguística que medem diferentes funções executivas (FES) (processos mentais responsáveis pela regulação, controle e gestão de outros processos cognitivos, tais como inibição, atenção, resolução de problemas, etc.). No entanto, pesquisas recentes têm mostrado que bilíngues tendem a apresentar uma vantagem mais robusta em tempos de reação (TRs) globais, ao invés de uma vantagem na magnitude do efeito de interferência. Independentemente de sua natureza, a chamada vantagem bilíngue já foi encontrada em diferentes grupos etários e entre diferentes tipos de bilíngues (e.g., Bialystok et al., 2004; Bialystok et al., 2005; Costa et al., 2008; Martin-Rhee & Bialystok, 2008), porém, às vezes, nenhuma vantagem bilíngue é de fato encontrada. O presente estudo tem o objetivo de replicar alguns dos experimentos já conduzidos com outras populações de participantes bilíngues e monolíngues quanto às FEs controle inibitório (Bialystok et al., 2004) e redes de atenção (Costa et al., 2008). Para isso, entrevistei e testei 40 executivos(as) de meia-idade (20 bilíngues idade média 48,1 e 20 monolíngues idade média 47,2) em duas tarefas de interferência não linguística: a tarefa Simon (Simon & Wolf, 1963), e a tarefa de rede atencional (ANT na sigla em inglês) (Fan et al., 2002). Executivos(as) enfrentam, naturalmente, uma alta demanda cognitiva em suas vidas diárias, tendo que constantemente resolver problemas que requerem decisões administrativas e financeiras, as quais envolvem muita responsabilidade e muitas pessoas, independentemente do produto ou serviço vendido ou oferecido pela empresa. Dessa forma, sua atividade profissional poderia fortalecer suas habilidades de controle inibitório e de resolução de problemas, o que poderia competir com as vantagens cognitivas advindas do bilinguismo. Em função disso, incluí um grupo controle que tem uma atividade profissional diferente, composto de 38 professores(as) de meia-idade (19 bilíngues idade média 46,6 e 19 monolíngues idade média 46,2), a fim de serem comparados aos executivos(as) na tarefa Simon. É importante ressaltar que nenhum estudo anterior investigou essas duas populações com esses mesmos propósitos. Além disso, percebi que há poucos estudos sobre os efeitos do bilinguismo quanto a adultos de meia-idade no que se refere a essas FEs, se comparados ao número de estudos e achados a respeito da vantagem bilíngue relativa a outros grupos etários. Os resultados obtidos com os(as) executivos(as) em ambas as tarefas não mostraram quaisquer vantagens bilíngues, seja no efeito de interferência ou em TRs globais. No entanto, não posso atribuir a ausência de uma vantagem bilíngue à variável Profissão como concorrente do bilinguismo, já que o grupo controle apresentou desempenho equivalente por parte de bilíngues e monolíngues na tarefa

Made available in DSpace on 2016-03-22T17:27:10Z (GMT). No. of bitstreams: 1 LEANDRA FAGUNDES DA SILVA.pdf: 1953423 bytes, checksum: 9e7974aa640e4a09429ddf30b255c215 (MD5) Previous issue date: 2013-11-20 / The results of several studies on bilingualism suggest a cognitive advantage due to code-switching, which creates a need for greater inhibitory control, one of the cerebral executive functions (e. g. BIALYSTOK et al., 2004; BIALYSTOK et al., 2005; MARTIN-RHEE; BIALYSTOK, 2008; COSTA et al., 2008). However, this advantage is not as evident in some studies, mainly when extralinguistic factors are controlled more strictly (MORTON; HARPER, 2007) or when attentional and inhibitory control are analyzed separately (BIALYSTOK et al., 2009). Regardless of the situation, the bilingual advantage over monolinguals has been investigated considering different age groups (children, young adults and the elderly). This study aims at investigating cognitive differences between mono and bilingual children who live in a border region, where the languages Portuguese and Spanish coexist, not only in personal, but also in social interactions in the community. In this study two nonlinguistic tasks and a linguistic one, which have been used in other studies (BIALYSTOK et al., 2005b; COSTA et al., 2008; YANG; LUST, 2011; PREUSS, 2011), were replicated, although not together and not necessarily with the same age group, according to the literature found. The replicated tasks focused mainly at investigating processes of inhibitory control and lexical access in bilingual speech production in Aceguá, a city in the border region between Brazil and Uruguay, which had not been analyzed yet, including bilingual children, speakers of Uruguayan Portuguese (DPUs)(ELIZAINCÍN, 2001), Brazilian Portuguese (PB) and Spanish (E). In order to achieve this goal, 60 children aged nine and ten (20 bilinguals (Aceguá) and 40 monolinguals (Aceguá and a control group from Pelotas)) were interviewed and tested with the following nonlinguistic tasks, the Simon Task (SIMON; WOLF, 1963) and the child version of the Attentional Network Task (RUEDA, et al., 2004), and also with the Lexical Access linguistic task (COSTA et al., 2000; PREUSS, 2011). The results obtained in the nonlinguistic tasks did not show cognitive differences between bilingual and monolingual children from the same region. The bilinguals were actually slower than the control group, suggesting that extralinguistic factors considerably influence the reliability of the results found by research on bilingualism, as evidenced in other studies (e. g. HILCHEY; KLEIN, 2011). The data show that a bilingual advantage in conflict resolution is sporadic and may even is absent, depending on the groups under analysis. Also, the results found between the two bilingual groups (Portuguese/Spanish and Spanish/Portuguese) did not show significant differences in order to assume the existence of psycholinguistic differentiation between the languages used in Aceguá/RS, once the advantage was present randomly in both groups when investigating the interference effects present in the bilingual speech involving two languages with semantic proximity. The general results of this study suggest the need for further investigations involving border bilingualism, with a bigger number of participants and also with strict control of extralinguistic factors, which can dramatically affect the identification of the bilingual cognitive advantage / Os resultados de vários estudos sobre bilinguismo sugerem uma vantagem cognitiva decorrente da prática da troca de códigos (code switching), que gera uma necessidade de maior controle inibitório, uma das funções executivas cerebrais (ex. BIALYSTOK et al., 2004; BIALYSTOK et al., 2005; MARTIN-RHEE; BIALYSTOK, 2008; COSTA et al., 2008). No entanto, essa vantagem não é tão evidente em alguns estudos, principalmente quando fatores extralinguísticos são controlados com maior rigor (MORTON; HARPER, 2007) ou quando controle de atenção e inibição são analisados em separado (BIALYSTOK et al., 2009). Independentemente da situação, a vantagem computada aos bilíngues sobre os monolíngues já foi pesquisada em diferentes faixas etárias (crianças, jovens adultos e idosos). Esta pesquisa visa investigar diferenças cognitivas entre crianças mono e bilíngues de região de fronteira, onde os idiomas do português e do espanhol convivem, tanto nas relações pessoais como nas sociais da comunidade. Na presente pesquisa foram replicadas duas tarefas não linguísticas e uma linguística, as quais já haviam sido utilizadas em outros estudos (BIALYSTOK et al., 2005b; COSTA et al., 2008; YANG; LUST, 2011; PREUSS, 2011), porém não em conjunto e não necessariamente para o mesmo grupo etário, de acordo com a bibliografia encontrada. As tarefas replicadas tiveram como principal objetivo investigar os processos de controle inibitório e de acesso lexical na produção de fala bilíngue na fronteira entre Brasil e Uruguai, na região de Aceguá, a qual não havia sido analisada ainda, em crianças bilíngues, falantes do português uruguaio (DPUs) (ELIZAINCÍN, 2001), do português brasileiro (PB) e do espanhol (E). Para atingir esse objetivo, foram entrevistadas e testadas 60 crianças na faixa etária compreendida entre nove e dez anos (20 bilíngues (região) e 40 monolíngues (região e grupo controle de Pelotas)) nas seguintes tarefas não linguísticas: Tarefa de Simon (SIMON; WOLF, 1963) e Tarefa de redes de atenção - ANT infantil (RUEDA, et al., 2004) e na tarefa linguística de Acesso Lexical (COSTA et al., 2000; PREUSS, 2011). Os resultados encontrados nos testes não linguísticos não apontaram diferenças cognitivas entre crianças bilíngues e monolíngues da mesma região. Os bilíngues foram inclusive mais lentos na comparação com as crianças do grupo controle, sugerindo que os fatores extralinguísticos influenciam consideravelmente na confiabilidade dos resultados de pesquisa sobre bilinguismo, como evidenciado em outros estudos (ex. HILCHEY; KLEIN, 2011). Os dados revelam que a vantagem bilíngue na resolução de conflitos é esporádica e pode inclusive ser ausente, dependendo dos grupos analisados. Também, os resultados encontrados entre os dois grupos bilíngues (Português/Espanhol e Espanhol/Português) não revelam diferenças significativas para afirmar a existência de diferenciação psicolinguística entre os idiomas praticados na região de Aceguá/RS, uma vez que a vantagem pendeu aleatoriamente para os dois grupos na investigação dos efeitos de interferência presentes na fala bilíngue quando dois idiomas de proximidade semântica são avaliados. Os resultados gerais da presente pesquisa sugerem a necessidade de mais estudos envolvendo bilinguismo fronteiriço, com maior número de participantes e também com o controle rigoroso dos fatores extralinguísticos, os quais podem afetar drasticamente a identificação da vantagem cognitiva de bilíngues.