AbstractsPsychology

This thesis investigates the link between domain-general cognitive system and bilingual language processing system, specifically linking executive control to bilingual language production and reading across varied communicative contexts. A fundamental question in bilingual language processing is whether language processing system is solely responsible for linguistic operations involved in language production and reading or whether it recruits, on demand, domain-general cognitive resources. Some bilingual language processing accounts (e.g., "mental firewall" accounts) posit that language processing system is architecturally blocked from the domain-general cognitive system, especially during earliest stages of processing. Contrastingly, inhibitory accounts posit that language processing system actively recruits domain-general cognitive resources, especially when task demands increase and often during earliest stages of processing. Effectively, we investigated the link between domain-general, non-linguistic executive control among bilinguals and bilingual language production in spontaneously produced monologues and dialogues (Chapter2); in sentence (Chapter 3, Experiment 1) and single word production (Chapter 3, Experiment 2) across single- and dual-language contexts; and sentence reading (Chapter 4). In Chapter 2, we found that individual differences in executive control related to acoustic indices but not to content indices of bilingual language production. Specifically, greater executive control related to more efficient ongoing speech planning and production processes, especially in cognitively more demanding L2 dialogues. In Chapter 3, the findings were two-fold. First, bilinguals recruited executive control to a greater extent when producing grammatically well-formed sentences in Experiment 1 versus single words in Experiment 2 and also when speaking in single- versus dual-language contexts. Second, greater executive control related to greater global (e.g., inhibit non-target language) versus local (e.g., inhibit specific words) language control in sentence production in Experiment 1. In Chapter 4, we found that greater executive control related to reduced early-stage cross-language activation, as indexed by semantically conflicting interlingual homographs (e.g., chat a casual conversation in English; French for cat) versus semantically congruent cognates (e.g., piano across English and French). Additionally, greater executive control guided enhanced later-stage use of sentence constraint when reading sentences with language-unique control words. Thus, bilinguals recruit executive control when processing demands increase, such as conversing in L2, or producing and reading L2 sentences. Bilinguals also recruit executive control, on demand, across early and late stages of language processing. La présente thèse porte sur le lien entre les contraintes cognitives générales et le traitement du langage chez le locuteur bilingue, notamment par rapport à la relation entre le contrôle exécutif et la production…