The ease at which individuals acquire a second language is astounding. Individuals are capable of learning a second language at any point through out their lifespan, although it is easier to learn a second language early in life. With increasing knowledge about linguistic neural processing and the brain’s capacity for plasticity, the research on bilingualism has increased substantially. Researchers have become increasingly more interested in the long-term effects of acquiring a second language, especially the enhancement of executive function (EF). This enhancement, also known as bilingual advantage, has been studied for a range of EFs, including inhibition, attention, problem solving, and reasoning. Although this effect was first demonstrated in bilingual children, researchers have extended the quest for understanding to young, middle, and older adults; however, the research findings are mixed for young adults. In order clarify these mixed results, the age of second language acquisition has been included as an experimental variable, producing three relevant groups: early bilinguals, late bilinguals, and monolinguals. There are several ways in which EFs can be measured, including behavioral rating scales, computerized cognitive tasks with behavioral outcomes (i.e., response times and accuracy), and computerized event-related potential cognitive tasks. A novel multi-level approach to measuring the bilingual advantage was developed and used as a framework for the current dissertation; i.e., the bilingual advantage was measured at three levels of measurement. This approach predicts that more complex levels of measurement (i.e., executive behaviors) would produce null findings between the three groups, while differences between early bilinguals and the other two groups would be predicted for less complex levels of measurement (i.e., neurophysiological markers). This approach predicts mixed results for levels of measurement that involve moderate complexity (e.g., computerized tasks of EF). Early bilinguals, late bilinguals, and monolinguals were compared across three hierarchical levels of measurement: (i) executive behaviors; (ii) information processing (i.e., computerized tasks of EF); and (iii) neurophysiology (i.e., event-related potential paradigm). Findings generally support the multi-level approach: no differences were found at the executive behavior level, limited and mixed differences were found at the information processing level, and differences between groups were found at the neurophysiological level. / Graduate

The purpose of this study was to examine the differences between the traditional global rating scale and a new behavioral rating scale in a university-based assessment center. It was hypothesized that personality factors, as measured by the 16PF and associated with the global ratings of performance would differ from those associated with the behavioral ratings of performance. It was further hypothesized that the associated personality factors would also differ for males and females. These hypotheses were ^confirmed. Pearson correlations were computed for ratings of males, females, and all subjects combined on both global and behavioral rating scales.

En raison du risque de perturbation des fonctions exécutives (FE), les recommandations médicales préconisent un suivi systématique du développement neuropsychologique des enfants atteints de phénylcétonurie, diagnostiqués et traités précocement (PCU-TP). En revanche, des divergences existent quant aux modalités pratiques d’évaluation. Ce travail de thèse a pour objectif d’interroger la pertinence de différents outils d’évaluation des FE en regard de la compréhension du phénotype neuropsychologique de ces enfants. Il s’agit d’apporter des préconisations d'évaluation puis de les confronter aux recommandations actuellement en vigueur. Dans ce contexte, 31 enfants PCU-TP ont été évalués à l’aide de tâches exécutives basées sur la performance et d’un questionnaire évaluant les comportements exécutifs à la maison et à l'école. Les résultats confirment la présence de difficultés exécutives par rapport à des enfants contrôles. Les difficultés décrites par l'entourage semblent majorées en regard des troubles observés aux tâches, suggérant que ces deux types d’outil évaluent des aspects exécutifs différents. Ce travail incite à préconiser l’utilisation d’outils variés et complémentaires et justifie la pertinence d’une évaluation plurielle et exhaustive des différentes composantes exécutives.Reste le problème majeur des outils actuellement disponibles. Dans cette perspective, la dynamique pluridisciplinaire associant cliniciens et universitaires est à encourager afin de proposer des outils fiables, permettant une évaluation puis une prise en charge au plus près des difficultés des patients. / Due to the risk of the impairment of Executive functions (EF), medical recommendations advocate asystematic follow up of the neuropsychological development for children with early and continuously treated phenylketonuria (ECT-PKU). However, there are discrepancies in the practical modalities of evaluation.This thesis is looking to question the relevance of the different evaluation tools for the EF with regards to the understanding of these children’s neuropsychological phenotype. It is about bringing evaluation recommendations and comparing them with the current guidelines. In this context, thirty one children with ECTPKU have been evaluated with executive tasks based on performance, and with a questionnaire assessing everyday executive functioning at home and at school.The results confirm some executive difficulties compared to control children. The difficulties described by the parents and teachers seem to be increased in relation to the disorders observed during the tasks. This suggests that these two types of tools evaluate different executive aspects. This work recommends the use of varied and complementary tools and it justifies the relevance of a plural and exhaustive evaluation of the different executive components. The major issue of the tools currently available remains. In this perspective, the pluridisciplinary dynamic associating clinicians and scholars is to be encouraged in order to offer reliable tools and thus allowing an evaluation, and a care and support, that are closer and more appropriate to the patient's difficulties.

Contexte : Les fonctions exécutives (FE) du syndrome de Gilles de la Tourette (SGT) demeurent à ce jour un sujet complexe. Les études tentent d’élucider l’implication des tics sur le fonctionnement cognitif, mais notent des résultats contradictoires. Ceux-ci seraient occasionnés par plusieurs facteurs, mais principalement par les comorbidités, incluant la dépression. Les risques de développer des symptômes dépressifs sont de 76 % dans la population du SGT. Toutefois, les études qui mettent en évidence un profil des fonctions exécutives à l’aide d’un questionnaire auto administré, tout en considérant les effets de la dépression, demeurent pratiquement absentes pour cette population. Ainsi, il est pertinent d’étudier ce sujet à l’aide d’un outil sensible aux atteintes exécutives afin de considérer ce besoin et d’édifier un portrait global du trouble. Objectifs : Le premier objectif sera de valider les relations entre les symptômes SGT, les symptômes dépressifs sous-cliniques (SDSC) et les sous-facteurs du BRIEF. Le deuxième objectif consiste à confirmer la nature des liens entre les évaluations du BRIEF-A et les différences entre les groupes atteints du SGT ou de tics chroniques (TC) avec ou sans SDSC et un groupe contrôle. Le troisième objectif vise à extraire un profil typique pour discriminer les groupes avec le BRIEF-A. Participants : Un groupe de 28 contrôles, 15 SGT ou TC et 16 SGT ou TC avec SDSC ont été recrutés. Ceux-ci ont été appariés selon l’âge et le sexe. Procédure : Le questionnaire auto-évalué et rapporté par les proches du BRIEF-A, l’inventaire de dépression de Beck (BDI), l’inventaire d’anxiété de Beck (BAI) et le YGTSS (Yale Global Tic Severity Score) ont été administrés. Résultats : Les résultats de l’ANOVA et des tests Welch, ainsi que les analyses de la fonction discriminante effectuées, révèlent un domaine caractérisant le SGT ou TC-SDSC soit l’inhibition. Conclusion : Le BRIEF-A permet de distinguer un profil exécutif propre aux personnes SGT ou TC avec SDSC. Les atteintes associées à l’inhibition seraient, en majeure partie, reliées aux SDSC et refléteraient une catégorie d’individu parmi la population SGT ayant développé une prédisposition à une dépression présentant une agitation psychomotrice. / Background: The executive functions (EF) of Gilles de la Tourette’s syndrome (TS) remain a complex subject to this day. Indeed, studies attempt to elucidate the implication of tics on cognitive functioning note mixed results. Several factors could influence these results, including significant comorbidities like depression. The chances of developing depressive symptoms in the TS population is as high as 76%. However, studies that highlight a profile of executive functions with a self-administered questionnaire and consider the effects of depression remain practically absent for this population. Thus, it is relevant to study this question using a tool sensitive to executive impairment to address this need and build a global portrait of the disorder. Objectives: The first objective will validate the relationships between TS symptoms, subclinical depressive symptoms (SCDS) and BRIEF sub-factors. The second objective is to confirm the nature of the BRIEF-A assessments and the differences between groups with TS or chronic tic (CT), TS or TC with SCDS and a control group based on BRIEF subfactors, TS symptoms and SCDS. The third objective is to extract a general profile to discriminate groups with the BRIEF-A. Participants: A group of 28 controls, 15 SGT or TC and 16 SGT or TC- SCDS, were recruited. They were matched by age and sex. Procedure: The BRIEF-A, a self-report version as well as the informant version, Beck’s Depression Inventory (BDI), Beck’s Anxiety Inventory (BAI) and the YGTSS (Yale Global Tic Severity Score) were administered. Results: The results of the ANOVA and the Welch, as well as the discriminant function analysis performed in the two versions of the BRIEF-A, reveal a domain that may characterize SGT or TC- SCDS: inhibition. Conclusion: The BRIEF-A makes it possible to distinguish a specific executive profile highlighting SGT or TC people with SCDS. The impairments measured in the executive function related to inhibition are mainly due to SCDS and could reflect a category of individuals among the SGT population with a predisposition to depression and psychomotor agitation.