The suggestion that bilinguals show enhanced cognitive control compared to monolinguals in certain aspects of executive function has received much contention. While this has been explained as a result of the extensive training in bilinguals having to manage the conflict that arises from their concurrently active langauges, others have argued that the superiority in executive control is attenuated when background variables such as immigration status, education and general cognitive ability is taken into account. This thesis was motivated by the general question: How is executive control influenced by differing bilingualism experiences? To this end, we compared attentional control performance in bilinguals and monolinguals on the Attention Network Test, the auditory Elevator task (Test of Everyday Attention), and the number Stroop task. The main aim of the thesis was to examine the role of two bilingualism factors: (i) interactional context (defined in the Adaptive Control Hypothesis, Green & Abutalebi, 2013), which pertains to how bilinguals switch between their languages, and (ii) linguistic distance, which refers to the extent of similarity between the bilingual's languages. The comparison between Edinburgh monolinguals, Edinburgh late bilinguals, Edinburgh early bilinguals, and Singapore early bilinguals as differentiated by their interactional context revealed better performance in bilinguals on two specific test components. Singapore bilinguals, who came from a dual-language and dense code-switching context, showed enhanced conflict resolution on the Attention Network Test, whilst Edinburgh late bilinguals, who were from a single-language context, were better on the Elevator reversal subtest tapping on attentional switching. The results thus suggest differential effects of interactional context on attentional control. We further compared task performance of bilinguals with related or distant L1-L2 combinations as defined by the linguistic and orthography overlap between their two languages. The data did not support a role of linguistic distance on attentional control. Edinburgh bilinguals studying an Indo-European language performed similarly to those studying the non Indo-European languages of Chinese and Japanese. In Singapore bilinguals, English-Chinese bilinguals also did not differ from English-Malay bilinguals on any of the test components. We supplemented the investigation by further examining if the factors of test-order and age could impact on how differences between monolinguals and bilinguals are exhibited. Our results suggest that monolinguals may show an improvement in attentional control after relatively short periods of engagement in experimental tasks, whilst bilinguals did not receive this boost. Test order may therefore partly explain the inconsistencies in literature regarding the claimed bilingual advantage. The comparison between older and younger adults also implied an effect of age. In young adults, bilinguals outperformed monolinguals on the Elevator reversal subtest of auditory switching, whereas the advantage shown in older bilinguals was on visual attentional orienting. The results across the various themes are reviewed and discussed with relevance to the current standing in the field, and suggestions for future research directions are put forth.

This thesis investigates individual differences and their impact on reading proficiency using different measures of proficiency, a variety of data collection and statistical methods, and different populations. The goal was to examine the impact that individual differences in certain reading-related skills and cognitive abilities have on reading proficiency and how these differences interact. Through three key studies that make up this thesis, several important discoveries and contributions were made to the field. Chapter 2 introduces an easy-to-use application for measuring cloze probability. ‘ClozApp’, was created and made publicly available, along with a user manual and sample code for programming. Chapter 3 contributed through the development of a novel statistical method used to analyze variance between populations with different linguistic backgrounds. This method was used to demonstrate how an individual’s linguistic background (i.e., whether they were first- or second-language speakers of English) impacted how individual differences in reading skills influence their reading fluency, as indicated through their eye-movements. This statistical prediction method is open source and was made widely available for use along with sample data and code. In Chapter 4, a new connection was found between two important cognitive factors that are well-known in the reading literature: statistical learning and motivation. Using mediation analyses, this project discovered an interaction between these factors that further highlights the ways they impact reading proficiency. This thesis demonstrates a comprehensive approach to investigating individual differences in reading proficiency in the following ways: (i) both reading fluency and comprehension were investigated as measures of reading proficiency, (ii) data collection included a variety of reading-related skills, cognitive abilities, and group differences, and (iii) unique statistical analysis methods were utilized to investigate both individual and group differences. This thesis highlights important new discoveries and makes significant lasting contributions to the field of reading research. / Thesis / Doctor of Philosophy (PhD) / This thesis investigates how individual differences influence reading proficiency. Specifically, it asks how the ways in which people differ on certain reading-related skills and cognitive abilities can determine how well they read. Using different measures of proficiency, a variety of data collection and statistical methods, and looking across different populations, the goal of this thesis was to examine the ways in which people differ in these skills and abilities, how these differences interact, and the resulting impact on reading proficiency. This thesis resulted in three significant contributions to the field. First, it made available a new application for collecting data on an important variable in reading research – cloze probability. In addition, it culminated in the development of a novel statistical method that demonstrates how an individual’s linguistic background can influence their reading fluency. Finally, a new connection was found between two important cognitive factors that interact to influence reading comprehension.

La langue est sans aucun doute le reflet d’une culture et en cela elle permet à deux peuples non seulement de communiquer mais aussi de se découvrir. C’est la raison pour laquelle ce travail vise à répondre à deux objectifs : le premier est d’optimiser l’enseignement des langues, ici le français en Corée, le second est de favoriser les échanges entre nos deux pays en mesurant la portée culturelle véhiculée par une langue. Pour cela nous avons cherché à identifier les contraintes de l’apprentissage du français en décrivant les interactions entre enseignants français natifs et apprenants coréens dans l’enseignement supérieur en Corée. La constitution d’un corpus d’interactions authentiques mettant en contact 180 apprenants coréens avec 7 enseignants au travers de 13 cours de FLE a permis de décrire des phénomènes interactionnels récurrents d’ordre sociolinguistique. La grande distance linguistique séparant le français du coréen s’est manifestée par des incompréhensions et des malentendus d’origine phonétique, morphosyntaxique et sémantique issus de transferts entre les deux langues. Pour surmonter ces difficultés linguistiques, nous préconisons d’accompagner les cours de grammaire d’une immersion en langue cible par des cours de conversation. Mais notre étude montre combien les habitudes d’apprentissage des apprenants coréens, entre silences, rire d’embarras, hochements de tête et autres gestes illustratifs palliatifs à des lacunes langagières, doivent être prises en compte dans toute démarche didactique. / The language is undoubtedly the reflection of a culture and it allows two peoples not only to communicate but also to discover each other. It is the reason why this work aims at answering two objectives: the first one is to optimize the languages teaching, here French in Korea, the second is to favour the exchanges between our two countries by measuring the cultural significance conveyed by a language. For this we tried to identify the constraints of the learning of French by describing the interactions between French native teachers and Korean learners in the higher education in Korea. The constitution of a corpus of authenticinteractions putting in touch 180 Korean learners with 7 teachers through 13 courses of FLE allowed to describe interactionnels recurring phenomena of sociolinguistic type. The linguistic great distance separating French of the Korean showed itself by incomprehensions and phonetic, morphosyntactic and semantic misunderstandings of origin stemming from transfers between both languages. To overcome these linguistic difficulties, we recommend to accompany the grammar courses with an immersion in target language by courses of conversation. But our study shows how many the learning habits of the Korean learners,between silences, laughter of embarrassments, nods and other palliative illustrative gestures in linguistic deficiencies, must be taken into account in any didactic approach.