A fundamental question of human existence is how much control we have on our behaviour. This dissertation aims to add to our understanding of cognitive control by characterising how a particular failure of performance, Goal Neglect (GN), is affected by different forms of complexity manipulations. In Chapter 2, I develop a new task to test GN and unlike previous studies, I manipulate complexity qualitatively by altering the instructional cues - the cues instructing the participant to shift to a different rule set. GN was sensitive to this kind of complexity manipulation and this is linked to a failure in recognizing the significance of the instructional cues. In Chapter 3, I propose a new entropy-like measure to quantify the temporal clustering of GN and use this to test the differential temporal patterns that are predicted by two theoretical models of GN. The results suggest that both models are likely to be operant, but with their relative dominance being different across time: GN early on in the task appears to be mostly driven by failures which are “task model” like, whilst GN which manifests later on is better aligned with the “monitoring” account. Chapter 2 also revealed that GN can be sensitive to manipulations of complexity during task performance, which motivated the question of whether previously published studies suggesting the contrary, were perhaps due to insufficient complexity. Hence, in Chapter 4, using the new GN task, I investigate this further. Overall, the results were mixed and indicated that complexity does not appear to affect GN unless the complexity manipulation is more closely associated to the critical event. Throughout this dissertation, I refer to models and empirical evidence from the Prospective Memory (PM) literature given the apparent similarity between PM and GN experimental paradigms. In Chapter 5, I take this further and investigate how PM failures and GN are different, if at all, with the broader aim to integrate what are otherwise isolated domains. I found a mixture of null findings which suggest that it is not entirely clear if GN and PMf reflect different capacities. Nonetheless, while investigating the differences between GN and PMf, a much more interesting question emerged with respect to what structural features of a task predict different signatures of GN-like and PMf-like errors. The key finding to this theory-neutral approach was a general rule about task structure: a combination of extended practice and low frequency of critical events predict both a larger amount of errors and with more of these occurring late in the task. Overall, this research has shed further light on task conditions that may result in different error signatures and that may reflect different cognitive resources.

Cruciale dans les apprentissages scolaires, la mémoire de travail (MDT) se développe avec l’avancée en âge. De précédente études ont démontré que la négligence du but contribuait au faible contrôle exécutif des enfants d’âge préscolaire. Par conséquent, présenter des indices de but durant une tâche améliore les performances des enfants dans des tâches d’inhibition et de flexibilité. Paradoxalement, quasiment aucune étude ne s’est interrogée sur le rôle que pourrait jouer un défaut de maintien du but dans les faibles performances des enfants les plus jeunes lors de tâches de MDT. Dans cette thèse, ce sujet a été traité en introduisant, durant la réalisation de tâches de MDT, des indices de but pouvant être exogènes (visuels ou auditivo-verbaux), exogènes et associés à un indiçage endogène (effectuer une gestuelle porteuse de sens), ou prendre la forme d’un jeu de rôle. Les résultats ont indiqué 1) que les enfants d’âge préscolaire répétaient plus fréquemment en présence d’un indiçage visuel sans toutefois que cela n’impacte les scores de rappel ; 2) qu’une association d’un indiçage exogène à un indiçage endogène améliore la MDT des enfants ; 3) qu’effectuer en premier une condition de jeu de rôle permettait aux enfants de conserver le même niveau de performances en MDT dans une condition subséquente sans jeu de rôle. Toutefois, A) un indiçage auditivo-verbal a détérioré les performances de rappel des enfants ; B) l’effet bénéfique de l’association des indiçages exogène et endogène n’a pas été reproduit ; C) l’effet bénéfique du jeu de rôle observé dans les études d’Istomina (1948) et de Bertrand et Camos (2015) ne fut pas répliqué. / Crucial in academic learning, working memory (WM) develops with age. Previous studies have shown that goal neglect contributed to kindergarteners’ poor executive control. Hence, presenting goal cues during a task improves children's performance in inhibition and switching tasks. Paradoxically, almost no study has questioned the role that failure to maintain the goal might play in the poor performance of younger children in WM tasks. In this thesis, this topic was been treated by introducing, during the retention interval in a Brown-Peterson task and in a simple or complex span task, goal cues that can be exogenous (visual or auditory-verbal), exogenous associated to an endogenous cueing (perform meaningful gestures) or taking the form of a role play. Results showed that 1) preschoolers rehearsed more frequently with a visual cue without improvement in their recall performance; 2) an association of an exogenous cue with an endogenous cue has improved kindergarteners’ WM performance; 3) performing a role play first allowed kindergarteners to maintain the same level of WM performance during a subsequent condition without role playing. However, A) an auditory-verbal cue was detrimental to kindergarteners’ recall; B) the beneficial effect of the association of exogenous and endogenous cues was not replicated; and C) the beneficial effect of role playing observed in Istomina (1948) and Bertrand and Camos (2015) was not replicated. This thesis proposes an opening towards the study of goal maintenance in visuo-spatial complex span tasks contrary to Brown-Peterson verbal tasks.