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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Subjective Experiences in Conflict Tasks

Questienne, Laurence 30 October 2017 (has links)
While performing a task, we feel cognitive and affective conscious experiences that we can subjectively evaluate. For instance, we can feel that we perform well or badly, or that the task is easy or difficult, etc. These subjective experiences could have an influence on behavioural adaptation. In the current thesis, we aimed to understand how these experiences emerge and how they are related to behavioural adaptation. In a first experimental study, we investigated, in the context of a conflict task, the relationship between the experience of conflict and the Gratton effect. This effect is considered as a hallmark of cognitive control. We replicated and generalised previous results (Desender, Van Opstal & Van den Bussche, 2014) that showed that metacognitive experiences of conflict are related to the Gratton effect. In the second study, we demonstrated that people are able to focus on highly specific aspects of their phenomenal experience (i.e. visual vs. motor conflict) that are usually confounded in conflict tasks. In the third and the fourth experimental study of the thesis, we focused on the experience of “urge-to-err”, i.e. the subjective feeling that one is about to make an error, even if the final response is correct. Using electromyography, we showed that this experience is highly determined by features of motor performance. We also demonstrated that subjective experiences of the urge-to-err result from several features that can be objectified and disentangled. Finally, we studied the temporal dynamics of the experience of urge-to-err by analysing the electroencephalographic markers that relate to judgements of urge-to-err. Results show that these judgements are rather blind to pre-response processing, and are mainly supported by tardive processes related to response evaluation.In sum, through different studies using behavioural, electromyographic and electroencephalographic measures, the current thesis discloses the building blocks of metacognitive experiences in the context of conflict task and uncover their mechanisms. This work also contributes to a better understanding of the relationship between subjective experiences and behavioural adaptation. / Lorsque nous réalisons une tâche, nous ressentons consciemment des expériences cognitives et affectives que l’on peut subjectivement évaluer. Par exemple, nous pouvons avoir l’impression que notre performance est plus ou moins bonne, ressentir que la tâche est plus ou moins difficile, etc. Ces expériences subjectives pourraient avoir une influence sur nos adaptations comportementales. Dans cette thèse de doctorat, nous avions pour objectif de comprendre l’émergence de ces expériences subjectives et leurs rôles dans nos comportements adaptatifs. Dans une première étude expérimentale, nous avons investigué la relation entre les expériences de conflit et l’effet Gratton dans le contexte des tâches de conflit. L’effet Gratton est considéré comme une signature comportementale de mécanismes de contrôle cognitif. Nous avons répliqué et généralisé de précédents résultats (Desender, Van Opstal & Van den Bussche, 2014) qui avaient montré que les expériences métacognitives du conflit sont liées à l’effet Gratton. Dans une seconde étude, nous avons montré que les participants sont capables de se concentrer sur des aspects très spécifiques de leur expérience phénoménale, ces aspects (conflit visuel et conflit moteur) étant habituellement confondus dans des tâches de conflit. Dans la troisième et quatrième étude de cette thèse, nous nous sommes concentrés sur l’expérience de « urge-to-err », c’est à dire le sentiment subjectif d’être sur le point de faire une erreur, bien que la réponse donnée soit finalement correcte. En utilisant des enregistrements électromyographiques, nous avons montré que cette expérience subjective résulte d'une combinaison de différents aspects de la tâche, dont en particulier la performance motrice. Finalement, nous avons étudié le décours temporel de l’émergence de l’expérience de « urge-to-err » en analysant les marqueurs électroencéphalographiques liés à cette expérience. Les résultats montrent que notre expérience subjective de « urge-to-err » est aveugle aux traitements cognitifs qui ont lieu avant la réponse motrice. Cette expérience est principalement sous-tendue par des traitements tardifs liés à l’évaluation de la réponse. En résumé, à travers différentes études utilisant des mesures comportementales, électromyographiques et électroencéphalographiques, la présente thèse révèle les éléments constitutifs des expériences métacognitives dans le contexte de tâches de conflit. Ce travail contribue également à une meilleure compréhension de la relation entre expériences subjectives et comportements adaptatifs. / Doctorat en Sciences psychologiques et de l'éducation / info:eu-repo/semantics/nonPublished
72

Investigating the Influence of Top-Down Mechanisms on Hemispheric Asymmetries in Verbal Memory

January 2013 (has links)
abstract: It is commonly known that the left hemisphere of the brain is more efficient in the processing of verbal information, compared to the right hemisphere. One proposal suggests that hemispheric asymmetries in verbal processing are due in part to the efficient use of top-down mechanisms by the left hemisphere. Most evidence for this comes from hemispheric semantic priming, though fewer studies have investigated verbal memory in the cerebral hemispheres. The goal of the current investigations is to examine how top-down mechanisms influence hemispheric asymmetries in verbal memory, and determine the specific nature of hypothesized top-down mechanisms. Five experiments were conducted to explore the influence of top-down mechanisms on hemispheric asymmetries in verbal memory. Experiments 1 and 2 used item-method directed forgetting to examine maintenance and inhibition mechanisms. In Experiment 1, participants were cued to remember or forget certain words, and cues were presented simultaneously or after the presentation of target words. In Experiment 2, participants were cued again to remember or forget words, but each word was repeated once or four times. Experiments 3 and 4 examined the influence of cognitive load on hemispheric asymmetries in true and false memory. In Experiment 3, cognitive load was imposed during memory encoding, while in Experiment 4, cognitive load was imposed during memory retrieval. Finally, Experiment 5 investigated the association between controlled processing in hemispheric semantic priming, and top-down mechanisms used for hemispheric verbal memory. Across all experiments, divided visual field presentation was used to probe verbal memory in the cerebral hemispheres. Results from all experiments revealed several important findings. First, top-down mechanisms used by the LH primarily used to facilitate verbal processing, but also operate in a domain general manner in the face of increasing processing demands. Second, evidence indicates that the RH uses top-down mechanisms minimally, and processes verbal information in a more bottom-up manner. These data help clarify the nature of top-down mechanisms used in hemispheric memory and language processing, and build upon current theories that attempt to explain hemispheric asymmetries in language processing. / Dissertation/Thesis / Ph.D. Speech and Hearing Science 2013
73

Task-goal switching: Influences of time, language, alertness and expertise

Slama, Hichem 16 April 2016 (has links)
Almost 100 years ago, Jersild (1927) published his article “Mental Set and Shift”. He borrowed this title from a book of Hollingworth and Poffenberger (1919), according to whom “shifting back and forth from one mental set, one attitude or one task to another, is a relatively ineffective mode of work.” As pointed out by Jersild, the cost of switching between activities or mental sets is, for instance, the reason for Taylor’s model of industrialization and the trend in industry toward specialization. Through specialization, the element of switch is reduced to its minimum because “the cost of shift is loss in efficiency” (Jersild, 1927). However, outside of the factory, switching between multiple tasks is a crucial part of human life and the cost of switching, consequently, impacts our everyday functioning.The main topic of this doctoral dissertation is cognitive flexibility and task switching. The task-switching paradigm requires participants to switch frequently between tasks. Therefore, it measures the capacity of our brain to adapt rapidly according to tasks and goals. Dynamic adaptation according to context and goals is encompassed in cognitive psychology and neurosciences under the term cognitive control. Consequently, the ability to switch between tasks constitutes the part of cognitive control that is needed when the current goal changes and the cognitive system has to adapt. Our experimental contribution aimed at investigating how this task-goal switching can be modulated by factors such as time, language, alertness and expertise. In this introduction, we succinctly review the vast literature about attentional systems, cognitive control and task switching. In the experimental section, we describe the cued match-to-sample task that we developed to investigate task-goal switching and present five experimental studies that address the impact of several factors on task-goal switching. In the general discussion, we summarize our results and consider their implications for cognitive-control and task-switching literatures. / Doctorat en Sciences psychologiques et de l'éducation / info:eu-repo/semantics/nonPublished
74

Influences non conscientes sur des processus mentaux complexes : initiation de stratégies et sentiment de contrôle / Unconscious influences on complex mental processes : task set initiation and feeling of control

Weibel, Sébastien 14 March 2014 (has links)
Est-ce que des stimuli non conscients peuvent modifier des processus classiquement considérés comme conscients ? Cette question est d’un intérêt particulier dans la schizophrénie où il existe à la fois des anomalies de processus implicites et des anomalies de processus conscients, comme par exemple, initier une stratégie ou se sentir en contrôle de son action. Pour réaliser des études chez les patients, nous devions savoir dans quelle mesure le choix d’une stratégie ou le sentiment de contrôler son action sont soumis à des influences non conscientes. Nous avons réalisé deux études chez le sujet sain montrant qu’un stimulus non conscient peut influencer la préparation d’une stratégie. Cependant, il existe des limites à ces influences non conscientes : le traitement du stimulus non conscient ne doit pas être interrompu trop tôt, et des filtres attentionnels le modulent. Notre troisième étude a analysé l’effet de distorsions subliminales du retour haptique (tactile et kinesthésique) sur l’adaptation motrice et sur le sentiment conscient de contrôler son action. Nous avons montré que le sentiment de contrôler l’action était modulé par des distorsions du retour haptique, même quand celui-ci est subliminaire. Les influences non conscientes ont un impact sur les processus habituellement conscients, dans des circonstances limitées et contrôlées. / Do unconscious stimuli modify processes that are typically associated with consciousness? This question is of particular interest in schizophrenia in which there is both impairments of implicit processes and abnormalities of conscious processes. For instance patients have difficulties to initiate a strategy or to feel in control of their actions. For this purpose, we wanted to know to what extent the choice of a task set or the feeling of control over the action could be influenced by unconscious cues. We conducted two studies in healthy subjects showing that unconscious stimuli can influence the preparation of a task set. However, we have shown that there are limitations to these unconscious influences: the processing of unconscious stimuli must be uninterrupted for some time, and it is modulated by attentional mechanisms. Our third study analyzed the effect of subliminal distortions of the haptic feedback (tactile and kinesthetic) on motor adaptation and on the conscious sense of control over the action. We have shown that the feeling of control was modulated by subliminal distortions of the haptic feedback. Unconscious influences have an impact on conscious processes, but in limited and controlled circumstances.
75

From self to social cognition : a new paradigm to study differentiations within the Theory of Mind mechanism and their relation to executive functioning

Bradford, Elisabeth E. F. January 2016 (has links)
Theory of Mind (ToM) refers to the ability to attribute mental states to oneself and other people. In this thesis, I present a new paradigm, the Self/Other Differentiation task, which was designed to assess ToM abilities – specifically, the ability to attribute belief states to the ‘Self' and ‘Other' – in typically developed, healthy adults. By focussing on fully developed ToM abilities, we aimed to increase understanding of how the ToM mechanism is structured and functions in everyday life, and how individual ToM components may differentially relate to executive functioning (EF) abilities. The Self/Other Differentiation task is a computerized false-belief task utilizing a matched- design to allow direct comparison of self-oriented versus other-oriented belief- attribution processes. Using behavioural (response times/error rates) and electrophysiological (EEG) methods, the work presented in this thesis provides evidence of a clear and distinct differentiation in the processing of ‘Self' versus ‘Other' perspectives in healthy ToM. We established a key role of perspective-shifting in ToM, which we hypothesize plays a crucial role in day-to-day communications; shifting from the Self-to-Other perspective was significantly harder (longer and more error prone) than shifting from the Other-to-Self perspective, suggesting that the ‘Self' forms the stem of understanding the ‘Other'. EEG analysis revealed these effects were present across fronto-lateral and occipital-lateral areas of the brain, particularly across the right hemisphere in parietal regions. We provide evidence of these features as universal, core components of the ToM mechanism, with data collected from both Chinese and Western cultures illustrating similar patterns of results. Results regarding the relationship between ToM and EF were mixed, with one study finding that affective EF positively correlates with ToM task performance, whilst non-affective EF does not, and a further two studies finding no such differential relationship. The Self/Other Differentiation task provides the opportunity to establish the features of ‘typical' ToM processes in healthy adults, to further our understanding of how the mature ToM mechanism functions.
76

Présence d'un schème trompeur dans un atelier d'aéronautique : manifestations et remédiation : assistance aux procédés de fabrication dans les ateliers du futur / Presence of a misleading scheme in an aeronautical factory : manifestations and remediation : assistance to the manufacturing processes in the workshops of future

Hoarau, Marie 22 June 2016 (has links)
L’évolution des technologies et la mutation du rôle attribué aux opérateurs de l’industrie suscitent un essor de la littérature concernant l’assistance aux procédés de fabrication. Cette thèse de psychologie s’inscrit dans cette littérature. Son objectif est de concevoir un assistant de contrôle aux procédés de fabrication, le compagnon virtuel, qui permette de maintenir à la fois les performances et les compétences des opérateurs. Le système étudié, une usine aéronautique, nécessite le recours à la simulation de processus physiques dynamiques. Deux champs de la littérature sont mobilisés : les cadres théoriques autour de la conception d’interfaces pour les environnements dynamiques et ceux sur le développement des compétences. Une méthodologie en trois parties est utilisée : (1) analyse de l’activité des opérateurs dans l’atelier réel, (2) validation d’un micromonde et (3) test d’un compagnon virtuel dans le micromonde. Les résultats montrent que les opérateurs de l’atelier réel mobilisent un schème trompeur lors de leur activité. Ce schème trompeur est également présent chez des participants tout-venants et il a un effet sur les performances des participants entrainés dans le micromonde. Enfin, le compagnon virtuel, conçu selon les principes de l’EID, ne permet pas de faire disparaitre le schème trompeur. Cependant, il permet aux participants qui n’utilisent pas le schème trompeur d’obtenir de bonnes performances. Les résultats obtenus étayent l’idée qu’il est pertinent de vérifier si des opérateurs ne mobilisent pas des schèmes trompeurs qui pourraient être un frein à l’utilisation des interfaces proposées pour les assister. / The evolution of technology and the shift in the role devoted to operators in industry, from simple task execution to complex system control, provoke a development of the literature concerning assistance to fabrication process. This thesis of psychology joins this literature. It aims at designing an assistant to fabrication process, called the virtual companion, which would both support performances and maintain or improve competences. In particular, the virtual companion would be addressed to operators in an aeronautical factory. The case study requires in line simulation of dynamic physical processes. Two fields of the literature were used: frameworks concerning interface design for dynamic situations and those concerning competences. A three-parts methodology was used: (1) activity analysis of the operators in the real factory, (2) conception and validation of a microworld, and (3) design and test of a virtual companion in the microworld. Results show that the operators of the factory use a misleading scheme during their activity. This misleading scheme is also used by random participants. Moreover, this misleading scheme has an effect on the performances of random participants trained in the microworld. Finally, the virtual companion, whose interface is design based on EID principles, does not eliminate the misleading scheme. However, the participants who did not use the misleading scheme performed better after using the virtual companion. This results leads to the conclusion that studying the operators’ use of misleading schemes seems accurate as such schemes may impair the use of interfaces designed to support their activity
77

Neural mechanisms of affective instability in substance use

Bodkyn, Carmen Noel 04 December 2017 (has links)
Substance use disorders (SUDs) are a growing concern in today’s society. Substantial research has advanced our understanding of how cognitive control, reward processing, and emotional difficulties may contribute to the development and maintenance of SUDs; however, the impact of affective instability in SUDs has received limited attention. I sought to examine how different dimensions of affective instability interact to increase substance misuse, and to investigate the impact of affective instability and substance use on neural mechanisms of reward and emotion processing. Specifically, I was interested in two event-related potential (ERP) components, the reward positivity and the late positive potential (LPP), which respectively reflect the neural mechanisms of reward and emotion processing. Toward this end, I recorded the ongoing electroencephalogram (EEG) from undergraduate students as they navigated two T-maze tasks in search of rewards. Further, one of the tasks included neutral, pleasant, and unpleasant pictures from the International Affective Picture System (IAPS). Participants also completed several questionnaires pertaining to substance use and personality. A principal components analysis (PCA) revealed a factor related to affective instability, which I named reactivity. This factor significantly predicted increased substance use. Interestingly, individuals reporting higher levels of affective reactivity also displayed a larger reward positivity following stimuli with emotional content. The current study identified a group of high-risk substance users characterized by greater levels of affective reactivity and increased reward processing. It is my hope that these results further elucidate the complexities of SUDs and help to create efficacious, individually-tailored treatment programs for those struggling with SUDs. / Graduate
78

The Brain is a Suitability Probability Processor: A macro model of our neural control system

Schindler, Eckhard 12 February 2021 (has links)
Our world is characterized by growing diversity and complexity, and the effort to manage our affairs in a good way becomes increasingly difficult. This is true for all spheres of life, including culture, economy, technology, science, politics, environment and daily grind. A corresponding development occurs to our understanding of the brain, which is the crucial organ to keep track of everything. The amount of domain specific findings about this organ grows dramatically, what takes preferably place by highly specialized research. But the holistic understanding of the brain is rather more challenged than supported by this development, resulting in a huge lack of knowledge on the systemic level of the neurosciences. Eckhard Schindler faces this dilemma by introducing a macro model of the brain. This is not only an attempt to improve the perception of our most crucial organ, but also to open a door for a better understanding of our species and for ease our life again.:Part 1 - The Brain as Suitability Probability Processor Introduction Neuro basics Purpose, perception and motor control Excitation, inhibition, pattern transformation and circuits Memory Homeostasis, pain, emotions and rewards The SPP model The emoti(onal-moti)vational system The control levels of the central nervous system The attention assessment controller (AAC) Efficiency through delegation and structuring Universal suitability probability evaluation Needs and library of associative-emotivational patterns Higher needs Needs and suitability probability evaluation Suitability probability evaluation and evolution The two types of consciousness Conscious experiences Individual and social consciousness The 4DI model A four-dimensional intelligence concept (4DI) Dynamics of the need hierarchy Social emotivational dependency chains The need for coherence Artificial needs versus growth needs Dynamics in the 3D tension field 3D tensions in the affluent society The tunnel vision paradox Emotivational amplification adaptation Fading consciousness in affluent contexts About the integrative ingredient of 4DI Toe-holds for other disciplines Part 2 - Excursions to the current state of science Introduction Basal ganglia (BG) and frontal cortex Emotion, motivation and memory Cognitive control and emotions Consciousness Psychology Brain and computer The biggest open questions Index of figures Index of tables References
79

PROACTIVE AND REACTIVE METACONTROL IN TASK SWITCHING

Moon Sun Kang (11688955) 12 November 2021 (has links)
<div>While cognitive control enables the selection of goal-relevant responses, metacontrol enables the selection of context-appropriate control operations. In task switching, metacontrol modulates task-switching efficiency by retrieving the associations between a contextual cue and a particular cognitive control demand. While the automatic retrieval of cognitive control is appealing due to its time and energy efficiency, the effects of different contextual cues have been shown in separate studies and appear to have different characteristics. Here, we devised a single task-switching paradigm to test whether we can observe both list-wide and item-specific metacontrol within subjects. In two experiments, we demonstrated reduced switch costs in lists associated with a high probability of switching as compared with lists with a low probability of switching (i.e., a list-wide switch probability [LWSP] effect). Similarly, we observed an analogous item-specific switch probability (ISSP) effect such that items associated with a high probability of switching incurred smaller switch costs as compared with items associated with a low probability of switching. We also confirmed that both list-wide and item-specific switch probability effects were not dependent on lower-level stimulus-response associations. However, the LWSP and the ISSP effects were uncorrelated, suggesting a lack of dependence. Together, these findings suggest that there are two distinct modes of metacontrol that are deployed in a context-sensitive manner in order to adapt to specific cognitive demands.</div>
80

Attention and executive control during lexical processing in aphasia

Evans, William Streicher 03 November 2015 (has links)
The goal of this project was to investigate the relationship between executive attention and specific linguistic and control processes during goal-directed tasks in aphasia. Its central premise was that PWA often possess dissociable impairments in linguistic processes and in the mechanisms that control and efficiently utilize those processes. The motivation for this claim was based on observations that PWA often present with deficits in the online processing of linguistic information, which in some instances have been interpreted as evidence for impaired linguistic operations, but in others has been interpreted as evidence for impaired control of language processing due to more general cognitive constraints. The current work tested claims regarding the Executive Attention model (Engle and Kane, 2004) in aphasia and its relation to varying task sets in linguistic and nonlinguistic tasks. 20 PWA and 23 matched controls were tested on four tasks measuring executive attention in verbal and nonverbal domains using word-picture interference, semantic and perceptual go/no-go, and spatial Stroop designs. Participants were also tested on lexical decision and numerosity judgment tasks with varying speed and accuracy-focused instructions, with performance modeled using the Diffusion Model (Ratcliff, 1978). Overall, the current work found evidence for the predicted domain-general and domain-specific impairments in executive attention at the level of individual PWA. However, these executive attention deficits did not appear to be associated with difficulties adapting to shifting speed-accuracy constraints. In addition, group-level patterns of performance across experiments suggest an additional related executive control deficit in the area of generating and maintaining arbitrary stimulus-response mappings. This study also demonstrated the appropriateness and potential applicability of the diffusion model in aphasia research, and diffusion model analyses found that PWA had difficulty adjusting their nondecision times in response to speed constraints, had lower drift rates in lexical decision, which reflected inefficient processing of lexical information, and had a disproportionately difficult time efficiently processing easy stimuli in lexical and numerosity tasks.

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