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60 (44 in the final sample) full-time or part-time employed or full-time student participants at the University of Central Florida were recruited to see whether a break in virtual nature will help improve upon executive functioning (EF) processing speed; especially in an EF impaired population. The main interest is that if virtual nature breaks aid with mental performance, then the application of virtual nature break can prove beneficial to both normal and, most importantly, the cognitively impaired. The lack of methodological consistency and the limited research on the subject yields mixed results in previous literature. The present study tries to address some of these gaps. Participants had to fill out a demographics survey, perform a cognitive load (Mental Rotation Task) and processing speed task (Stroop Color-Word Task), and then engage in a simulated 15-minute break in nature (video & sounds). Afterwards, they performed the processing speed task again to measure for change. The results failed to demonstrate that a moderately short break consisting of a nature video helps boost EF performance in the normal group. Those who demonstrated impairment in EF in the treatment group had to small of a sample size to be tested on. Numerous limitations and weak statistical power, especially in the impaired group, calls into question the validity of the study. As a result, the study findings are inconclusive.

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Age affects hearing and cognitive abilities. Older people, with and without hearing impairment (HI), exhibit difficulties in hearing speech in noise. Elderly individuals show greater difficulty in segregating target speech from distracting background noise, especially if the noise is competing speech with meaningful contents, so called informational maskers. Working memory capacity (WMC) has proven to be a crucial factor in comprehending speech in noise, especially for people with hearing loss. In auditory scenes where speech is disrupted by competing speech, high WMC has proven to facilitate the ability to segregate target speech and inhibit responses to irrelevant information. People with low WMC are more prone to be disrupted by competing speech and exhibit more difficulties in hearing target speech in complex listening environments. Furthermore, elderly individuals with a HI experience more difficulties in switching attention between wanted and irrelevant stimuli, and they employ more resources and time to attend to the stimuli than do normally - hearing (NH) younger adults. This thesis investigated the importance of inhibitory control and WMC for speech recognition in noise, and perceived listening effort. Four studies were conducted. In the first study, the aim was to develop a test of inhibitory control for verbal content, and to investigate the relation between inhibitory control and WMC, and how these two abilities related to speech recognition in noise, in young normally – hearing (YNH) individuals. In the second study we aimed to investigate the same relationship as in the first study to further strengthen the validity of the inhibitory test developed, as well as the importance of lexical access. It was also an aim to investigate the influence of age and hearing status on lexical access and WMC, and their respective roles for speech recognition in noise in both YNH and elderly HI (EHI) individuals. Study one and two showed that, for YNH, inhibitory control was related to speech recognition in noise, indicating that inhibitory control can help to predict speech recognition in noise performance. The relationship between WMC and speech recognition in noise in YNH shifted in the studies, suggesting that this relationship is multifaceted and varying. Lexical access was of little importance for YNH, although for EHI individuals, both WMC and lexical access was of importance for speech recognition in noise, suggesting that different cognitive abilities were of importance for the YNH and EHI individuals Study three investigated the relationship between inhibitory control, WMC, speech recognition in noise, and perceived listening effort, in YNH and elderly, for their age, NH, individuals (ENH). In study four the same relationships as in study three were investigated, albeit in EHI individuals. Two speech materials with different characteristics, masked with four background noises were used. The results in study three showed that less favourable SNRs were needed for informational maskers than for maskers without semantic content. ENH individuals were more susceptible to informational maskers than YNH individuals. In contrast, in study four, more favourable SNRs were needed for informational maskers. In both studies, results showed that speech recognition in noise performance differed depending on the characteristics of the speech material. The studies showed that high WMC, compared to low WMC, was beneficial for speech recognition in noise, especially for informational maskers, and resulted in lower ratings of perceived effort. Varying results were found in study three and four regarding perceived effort and inhibitory control. In study three good inhibitory control was associated with lower effort rating, while in study four, individuals with a HI and good inhibitory control rated effort as higher. The results suggest that hearing status, age, and cognitive abilities, contribute to the differences in performance between YNH, ENH, and EHI individuals in speech – recognition – in – noise - and cognitive tasks. This thesis has, for the first time, demonstrated that a measure of inhibitory control of verbal content, is related to speech recognition in noise performance in YNH, ENH and EHI individuals. Results presented in this thesis also show that both WMC and inhibitory control are related to an individuals’ perception of how effortful a listening task is. It also adds to the literature that WMC is related to speech recognition in noise performance for ENH and EHI individuals, but that this relationship is not as robust in YNH individuals. / Ålder påverkar hörseln och de kognitiva förmågorna. Äldre personer, med och utan hörselnedsättning, uppvisar ofta svårigheter att höra tal i miljöer med bakgrundsljud. De uppvisar större svårigheter att urskilja en måltalare, speciellt om det omgivande ljudet består av annat tal med meningsfullt innehåll, så kallad informationsmaskering. Arbetsminne har visat sig vara en viktig faktor för att förstå tal – i – brus, framför allt för personer med hörselnedsättning. I ljudmiljöer där tal störs av andra talkällor är hög arbetsminneskapacitet av vikt för att understödja förmågan att urskilja måltalaren från de störande talkällorna genom att underlätta inhiberingen av irrelevant information. Individer med lägre arbetsminneskapacitet är mer benägna att störas av andra talkällor, och har svårare att uppfatta måltalaren i komplexa lyssningssituationer. Vidare upplever äldre personer med hörselnedsättning att det är svårare att skifta uppmärksamheten mellan relevant och irrelevant stimuli, och de använder mer resurser och tid till omgivande stimuli än, ex. yngre individer med normal hörsel. I den här avhandlingen undersöktes vikten av inhibitionskontroll och arbetsminne vid taluppfattning i brus och upplevelsen av lyssningsansträngning. Fyra studier genomfördes. Syftet med första studien var att utveckla ett test för verbal inhibitionskontroll, och att undersöka relationen mellan inhibitionskontroll, arbetsminneskapacitet, och deras koppling till taluppfattning i brus hos yngre normalhörande personer. I studie två undersöktes ovanstående relationer för att vidare styrka validiteten för testet av inhibitionskontroll, samt vikten av lexikal åtkomst. Vidare syfte var att undersöka ålderns och hörselns inverkan på lexikal åtkomst och arbetsminneskapacitet, och deras respektive roller för taluppfattning i brus hos både yngre normalhörande och äldre hörselnedsatta personer. Studie ett och två visade att inhibitionskontroll var relaterad till taluppfattning i brus för yngre normalhörande personer, vilket indikerar att inhibitionskontroll kan användas för att underlätta att förutsäga förmågan att uppfatta tal – i – brus. Relationen mellan arbetsminneskapacitet och taluppfattning i brus hos yngre normalhörande var inte solid, vilket tyder på att relationen är mångsidig och skiftande. Lexikal åtkomst var av mindre betydelse för yngre normalhörande personer, ehuru hos äldre hörselskadade personer var både arbetsminneskapacitet och lexikal åtkomst viktigt för taluppfattning i brus. Detta tyder på att olika kognitiva förmågor var betydelsefulla för taluppfattningen i brus för yngre normalhörande och äldre hörselskadade personer. Studie tre undersökte relationen mellan inhibitionskontroll, arbetsminneskapacitet, taluppfattning i brus, och upplevd lyssningsansträngning hos yngre och äldre, för sin ålder, normalhörande personer. Två talmaterial med olika karakteristika användes och maskerades med fyra olika bakgrundsbrus. Resultatet visade att mindre gynnsamma signal – brus - förhållanden uppnåddes när informationsmaskering användes jämfört med brus utan semantiskt innehåll. Äldre normalhörande personer var mer mottagliga för informationsmaskering än yngre normalhörande personer. Hög arbetsminneskapacitet och god inhibitionskontroll var förmånliga för taluppfattning i brus, och resulterade i mindre upplevd lyssningsansträngning, jämfört med personer med lägre arbetsminneskapacitet och sämre inhibitionskontroll. Resultaten talar för att åldersrelaterade tillbakagångar i hörförmåga och, vissa, kognitiva förmågor, bidrar till skillnaderna i prestation mellan yngre och äldre normalhörande personer när det gäller förmågan att uppfatta tal - i - brus. Studie fyra undersökte samma relationer som i studie tre, ehuru hos äldre personer med mild – måttlig sensorineural hörselnedsättning. Resultaten visade att förmågan att uppfatta tal - i - brus varierade beroende på talmaterialets karakteristika, samt vilket bakgrundsbrus som användes. Hög arbetsminneskapacitet och god inhibitionskontroll var fördelaktiga för taluppfattningen, i synnerhet när informationsmaskering användes. Personer med högt arbetsminne upplevde mindre lyssningsansträngning, medan god inhibitionskontroll associerades med högre upplevd lyssningsansträngning. I föreliggande avhandling har det, för första gången, påvisats att verbal inhibitionskontroll relaterar till förmågan att uppfatta tal – i – brus hos yngre och äldre normalhörande, och äldre personer med hörselnedsättning. Resultaten som presenterats i avhandlingen visar att både arbetsminneskapacitet och inhibitionskontroll är associerade med en individs upplevelse av hur ansträngande en lyssningssituation är. Avhandlingen stödjer även tidigare forskning som visar på att arbetsminneskapaciteten är relaterad till förmågan att uppfatta tal – i – brus hos äldre  normalhörande, och äldre hörselskadade personer, men att denna relation inte är lika solid för yngre normalhörande personer.

Les personnes vieillissantes doivent composer au quotidien avec des douleurs chroniques. Le but de ce travail est de mieux comprendre les mécanismes sous-jacents qui contribueraient aux douleurs chroniques liées au vieillissement et par là, ouvrir un chemin vers de nouvelles perspectives thérapeutiques. Les contrôles inhibiteurs diffus nociceptifs (CIDN) ont un rôle qui n’est pas des moindres dans le contrôle de la douleur. Des études expérimentales examinant l’effet analgésique de la contre stimulation hétérotopique nociceptive (HNCS), un protocole permettant de tester l’efficacité de ces CIDN, suggèrent que le recrutement des CIDN au sein de cette population était plus faible (i.e. moins d’inhibition) comparé à une population plus jeune. En revanche, les études examinant la sensibilisation centrale induite par sommation temporelle (TS) de la douleur rapportent des résultats mitigés. De plus, une composante importante influençant l’expérience de douleur, les ressources cognitives, dont l’inhibition cognitive, se voient aussi décliner avec l’âge. Premièrement, le recrutement des CIDN a été comparé entre des participants sains, jeunes et des plus âgés avec la HNCS, et le recrutement des mécanismes de sensibilisation centrale avec la TS. La stimulation électrique du nerf sural a été choisie pour permettre de quantifier la douleur, tout en prenant une mesure indicative de la nociception spinale qu’est le réflexe nociceptif spinal (RIII). Nos sujets ont aussi participé à une tâche cognitive (le Stroop), testant l’inhibition cognitive. Deuxièmement, l’efficacité des CIDN ainsi que de l’inhibition cognitive a été testée chez les jeunes et les aînés en imagerie par résonance magnétique (IRM), afin de vérifier la relation entre ces deux mesures psychophysiques et l’épaisseur corticale des régions qui y sont impliquées ainsi que l’effet de l’âge sur celles-ci. Les résultats suggèrent un moindre recrutement des CIDN chez les plus âgés lors de l’expérimentation de la HNCS. Également, les sujets âgés présentaient des capacités d’inhibitions cognitives plus faibles que les jeunes. En plus, une corrélation entre l’inhibition cognitive et la modulation du réflexe RIII par la HNCS a été mise en évidence. Pour l’expérience de TS, les résultats étaient comparables pour les deux groupes, suggérant que les mécanismes impliqués dans la régulation de la douleur ne subiraient pas l’effet de l’âge de la même manière. Pour l’étude de l’épaisseur corticale, on y trouve une diminution globale de l’épaisseur corticale liée à l’âge, mais aussi une corrélation de l’analgésie par la HNCS avec l’inhibition cognitive et également, une relation des deux avec l’épaisseur corticale du cortex orbitofrontal (OFC) latéral gauche, suggérant la possibilité d’une existence d’un réseau neuronal au moins partiellement commun du contrôle inhibiteur descendant sensoriel et cognitif. Ce travail montre que l’effet de l’âge sur les mécanismes centraux de la régulation de la douleur est loin d’être uniforme. Également, il montre une corrélation entre la modulation endogène de la douleur et l’inhibition cognitive, ces deux processus seraient associés à une même région cérébrale. Ces résultats pourraient contribuer à identifier d’autres méthodes thérapeutiques, ouvrant ainsi une nouvelle avenue vers d’autres options dans la prise en charge des douleurs chroniques chez les personnes vieillissantes. / Elderly have to deal daily with chronic pain. The diffuse inhibitory descending controls (DNIC) are much involved in the pain control. It was shown that the DNIC recruitment was lower in elderly than in young population, using the analgesic effect of the heterotopic noxious counter stimulation (HNCS), a protocol allowing testing the efficiency of the DNIC. However, the studies assessing the central sensitization by the temporal summation of pain after repetitive stimuli have reported mixed results, the effect of age is still unclear. In addition, there is an age-related decline of an important component, which has an influence on pain perception, the cognitive resources and especially the cognitive inhibition. The goal of this work is to understand the underling mechanisms of the chronic pain related to the normal aging, which can leads to a new therapeutic perspectives. First, the recruitment of the CIDN was compared between healthy young and elderly participants using the HNCS, and the central sensitization was tested using TS. The sural nerve electric shock stimulation was chosen, because it allows us to have two measures, the pain rating and the nociceptive spinal reflex (RIII), an indicative measure of the nociception. Our participants were also invited to participate in a cognitive task (the Stroop), to assess the cognitive inhibition. Second, the efficacy of the CIDN and the cognitive inhibition in elderly and young participants was tested, but this time in a magnetic resonance imaging session. We have wanted to test the association between these two-psychophysics measures, with the cortical thickness of the regions involved into these two processes, and the effect of the normal aging on them. The results have showed a less recruitment of the DNIC in elderly in the HNCS experiment. Also, the elderly have performed less than young in the cognitive inhibition. In addition, a correlation between the cognitive inhibition and the modulation of the RIII-reflex was found. For the TS experiment, no difference was shown between the two groups, suggesting that aging may affect differently the mechanisms involved in endogenous pain modulation. The morphometric study has showed a global diminution of the cortical thickness with aging. Furthermore, there was an association, between the HNCS analgesia and the performance in cognitive inhibition, and between theses two processes and the cortical thickness of the left lateral OFC. These results suggest an eventual existence of at least a partial neuronal common network for the sensorial and cognitive descending inhibitory control. This thesis has showed that the effect of normal aging on the central mechanisms of the pain regulation might be not uniform. Also, on one hand a correlation between the endogenous modulation of pain and cognitive inhibition was reported, and on the other hand that these two processes would be related to the same cortical area. Together, these findings would help to develop new therapeutic methods and offer more options to the management of pain in the elderly.

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.

Identifying the causes and consequences of intra-specific variation in cognitive abilities is fundamental to our understanding of the evolution of cognition. The social environment and cognitive abilities appear inextricably linked, yet evidence for how the social environment affects cognitive performances and further, how cognitive performances influence the social environment, has seldom been explored. Using the pheasant, Phasianus colchicus, I explore the relationships between individual variation in cognitive performances in relation to broad and fine-scale structure of the social environment and endeavour to separate cause and consequence. I demonstrate a positive causal effect of the broad-scale social environment on cognitive performances by observing increases in the accuracy of spatial discrimination performances when individuals are in larger groups (Chapter Two and Chapter Four). I show that the positive effects of larger group size occur over a relatively short period (less than one week), suggesting that cognitive performances are flexible in response to the social environment and I suggest four potential mechanisms. I show that while males are part of a social hierarchy, spatial discrimination performances are related to this fine-scale social structure and higher-ranking males outperform lower ranking males (Chapter Three). When attempting to determine cause and consequence, I found that spatial learning performances early in life did not predict adult cognitive performances on the same task or predict their adult social rank (Chapter Four). Hence, my results do not support that social rank is a consequence of spatial learning abilities in male pheasants. The relationship between spatial learning performances and social rank was found in adult males that had their social rank artificially elevated, suggesting that cognitive performances were not simply the result of the current social environment but remain closely related to past agonistic relationships. I did not find a relationship between early life aggression with performances on either a spatial or a non-spatial task in females or males (Chapter Five). This highlights the importance of investigating early life relationships and suggests that the relationship between spatial learning and aggression in adult males may become associated over time as a consequence of further spatial learning experiences, and, or, aggressive interactions. I then demonstrate a consequence of individual variation in cognitive abilities and show that adult foraging associations in the wild disassort by early life cognitive performances (Chapter Six). Individuals with good inhibitory control performance and poor visual discrimination performances were more central in social networks. I propose that differences in cognitive abilities manifest in foraging strategy and influence the resulting social structure. The implications of this predictable social structure remain to be explored. Finally, I discuss these results and how they contribute to our understanding of how the social environment causes individual differences in cognitive performances, as well as how variation in cognitive performances may shape the social environment. I suggest the potential implications of these findings and ideas for future work.

L'inhibition de réponse joue un rôle majeur dans le contrôle cognitif. Mais les relations entre activité cérébrale et comportement sont particulièrement difficiles à appréhender puisque la fonction est précisément destinée à prévenir tout comportement observable… Dans une première partie, nous proposons une revue de questions mettant en évidence la nécessité d'utiliser des méthodes psychophysiques adaptées. Nous proposons également une analyse systémique des travaux utilisant l'électroencéphalographie, méthode largement privilégiée pour sonder la dynamique des mécanismes inhibiteurs. Dans une seconde partie, nous mettons en œuvre ces propositions dans le cadre d'une étude combinée EEG/IRMf. Grâce à des méthodes avancées de traitement du signal EEG, nous suggérons la mise en jeu de mécanismes automatiques, non sélectifs, d'inhibition de réponse dès lors que le contexte événementiel est incertain. Il reposerait sur la pré-activation d'une circuiterie auto-inhibitrice dans le complexe moteur supplémentaire, implémenté par un large réseau médial frontopariétal. Dans les troisième et quatrième parties, nous montrons le rôle majeur de cette fonction dans d'autres processus cognitifs et illustrons les conséquences cliniques de son dysfonctionnement. Nous montrons en particulier que l'impulsivité n'est pas la seule expression des troubles du contrôle inhibiteur. La difficulté à initier une action constituerait, dans la maladie de Parkinson, une conséquence directe de ce dysfonctionnement. L'implication d'une dérégulation du système noradrénergique et de l'activité du noyau sous-thalamique dans l'occurrence du trouble est suggérée, et les perspectives thérapeutiques discutées / Response inhibition plays a major role in cognitive control. Understanding these mechanisms is essential because their dysfunctions may cause symptoms in many psychiatric and neurological diseases. The relationship between brain activity and behavior are particularly difficult to understand because the function of interest is specifically intended to prevent any observable behavior… In the first part, we propose a review of issues highlighting the need for a new theoretical model and adapted psychophysical methods. We also provide systematic analysis of studies using electroencephalography, widely preferred method for probing the dynamics of inhibitory mechanisms. Convergently, the review calls for revisiting both acquisition methods and processing methods of EEG signal used in conventional studies. In the second part, we implement these proposals by combining advanced treatment methods of EEG signal (blind source separation, analysis test by test, spectral analysis in the sources, location) and comparing these results with the fMRI data. We reveal the involvement of automatic and nonselective inhibitory mechanisms, when the context is uncertain. A large medial frontoparietal network would ensure the implementation. The involvement of an automatic behavior (when the environment becomes predictable) would require a top-down control that deactivates in advance the excitability of the self-inhibitory circuitry of the SMC. In the third and fourth sections, we show the key role of this function in other cognitive processes and illustrate the clinical consequences of its dysfunction. We show in particular that the difficulty in initiating an action (akinesia) would, in Parkinson’s disease, a direct consequence of this dysfunction. The involvement of the noradrenergic system and the activity of the subthalamic nucleus in the occurrence of the disorder are suggested, and therapeutic perspectives discussed