Bilinguals have repeatedly shown to have better results than monolinguals in non-verbal cognitive tasks that require inhibition of distracting stimuli. Evidence suggests that this enhanced performance is due to training effects of non domain specific executive functions, and that this gain in cognitive performance can contribute to a cognitive reserve in old age. One of the most frequently used methods when studying the relationship between second language proficiency and cognitive abilities is the Simon task in the visual sensory modality. The present study aimed to determine if the advantage found in the visual Simon task also could apply to a tactile Simon task. The sample consisted of 40 individuals aged 43 to 64 with different levels in their second language. An operational span test (OSPAN) was used to control for working memory capacity. No significant correlation was found between bilingualism and the Simon effect in either modality. Since the study has low statistical power and a small range in second language proficiency, it was concluded that further research investigating whether the bilingual advantage found in the visual Simon task can be found across modalities is necessary before any conclusions regarding a relationship between bilingualism and cognitive control can be made.

There is no consensus on the relationship between working memory resources and mind wandering. The purpose of the current study is to investigate whether mind wandering requires working memory resources to be sustained. The resource-demanding view is that mind wandering requires working memory resources to sustain an internal train of thought (Smallwood, 2010). The resource-free view is that mind wandering is a result of executive control failures and this internal train of thought proceeds in a resource-free manner (McVay & Kane, 2010). Participants were presented with thought probes while they performed a Simon task in single and dual task conditions. From the resource-demanding view, individuals with high WMC should experience more Task unrelated thought (TUT) in single and dual task conditions compared to those with low WMC. From the resource-free view, individuals with high WMC should experience fewer TUT compared to low WMC individuals. Results indicated that, WML eliminated the Simon effect for high WMC and reduced it for low WMC group. Mind wandering was decreased in dual task conditions however there was no effect of working memory capacity on mind wandering. Also, mind wandering correlated with task performance measures for the low WMC but not high WMC group. The results of the current study do not provide strong support for either a resource-demanding or resource-free view and are discussed in terms of a context dependent relationship between WMC and mind wandering

Le but de ce travail de thèse était de contribuer à une meilleure compréhension des mécanismes par lesquels nous nous représentons nos propres actions et celles d'autrui. En nous situant notamment dans la perspective de la théorie idéomotrice, nous avons examiné ces questions tout d'abord dans le cadre de l'imitation. Nos résultats indiquent un effet de l'apprentissage idéomoteur sur l'imitation intentionnelle (Etude 1), confirmant la flexibilité des liens perception-action, et démontrant le rôle des associations réponse-effet dans l'imitation. Toutefois, les performances à une tâche d'imitation automatique n'étaient pas influencées par un tel type d'apprentissage (Etude 2), possiblement en raison de processus différents n'ayant pas la même sensibilité à l'apprentissage idéomoteur. Nous avons ensuite étendu nos recherches au cadre des tâches conjointes (Etude 3). Nous montrons qu'une expérience idéomotrice corrélant l'exécution d'une action avec celle d'un agent non-humain conduit à la co-représentation de l'action de cet agent (présence d'un effet Simon social). Ainsi, l'expérience idéomotrice pourrait également permettre de modifier la co-représentation de l'action d'autrui en situation de tâche partagée. Ce travail confirme donc l'approche idéomotrice de la perception et de la représentation des actions d'autrui. / The aim of present work was to better understand the mechanisms by which we represent our own actions and those of others. Within the frame of the ideomotor theory, we first examined these questions in relation to imitation. Our results indicated an effect of ideomotor learning on intentional imitation (Study 1), confirming the flexibility of perception-action links, and demonstrating the role of action-effect associations in imitation. However, automatic imitation was not influenced by this type of learning (Study 2), which may suggest different processes with less sensitivity to learning ideomotor learning. We then extended our research to joint-action tasks (Study 3). We showed that an ideomotor experience, where action execution triggered actions of a non-human agent, induced a subsequent co-representation of this agent's actions (as indexed by social Simon effect). Ideomotor experience therefore seems to influence also the way we represent the actions of others in task-sharing. This work confirms the ideomotor approach to perception and representation of others' actions.