5 research outputs found

    Empirical tests of a brain-based model of executive function development

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    Executive function (EF) plays a foundational role in development. A brain-based model of EF development is probed for the experiences that strengthen EF in the dimensional change card sort task in which children sort cards by one rule and then are asked to switch to another. Three-year-olds perseverate on the first rule, failing the task, whereas 4-year-olds pass. Three predictions of the model are tested to help 3-year-olds (N = 54) pass. Experiment 1 shows that experience with shapes and the label “shape” helps children. Experiment 2 shows that experience with colors—without a label—helps children. Experiment 3 shows that experience with colors induces dimensional attention. The implications of this work for early intervention are discussed

    Energy landscape and dynamics of brain activity during human bistable perception.

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    Individual differences in the structure of parietal and prefrontal cortex predict the stability of bistable visual perception. However, the mechanisms linking such individual differences in brain structures to behaviour remain elusive. Here we demonstrate a systematic relationship between the dynamics of brain activity, cortical structure and behaviour underpinning bistable perception. Using fMRI in humans, we find that the activity dynamics during bistable perception are well described as fluctuating between three spatially distributed energy minimums: visual-area-dominant, frontal-area-dominant and intermediate states. Transitions between these energy minimums predicted behaviour, with participants whose brain activity tend to reflect the visual-area-dominant state exhibiting more stable perception and those whose activity transits to frontal-area-dominant states reporting more frequent perceptual switches. Critically, these brain activity dynamics are correlated with individual differences in grey matter volume of the corresponding brain areas. Thus, individual differences in the large-scale dynamics of brain activity link focal brain structure with bistable perception

    Nature of crossmodal plasticity in the blind brain and interplay with sight restoration

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    ThĂšse rĂ©alisĂ©e en cotutelle avec l'UniversitĂ© catholique de Louvain.Ce travail de thĂšse s’est intĂ©ressĂ© Ă  la plasticitĂ© cĂ©rĂ©brale associĂ©e Ă  la privation/restauration visuelle. A travers deux Ă©tudes transversales utilisant l’imagerie par rĂ©sonance magnĂ©tique fonctionnelle auprĂšs d’un groupe de participants prĂ©sentant une cĂ©citĂ© congĂ©nitale ou prĂ©coce (ainsi qu’auprĂšs d’un groupe contrĂŽle de participants voyants), nous avons tentĂ© de caractĂ©riser la maniĂšre dont le cortex occipital - typiquement dĂ©diĂ© au traitement de l’information visuelle - se rĂ©organise afin de traiter diffĂ©rents stimuli auditifs. Nous dĂ©montrons qu’en cas de cĂ©citĂ© prĂ©coce, diffĂ©rentes rĂ©gions du cortex occipital prĂ©sentent une prĂ©fĂ©rence fonctionnelle pour certains types de stimuli non-visuels, avec une spĂ©cialisation fonctionnelle qui respecte celle de rĂ©gions typiquement impliquĂ©es dans le traitement d’informations similaires en vision. Ces dĂ©couvertes constituent une avancĂ©e conceptuelle concernant le rĂŽle jouĂ© par les contraintes intrinsĂšques d’une part, et par l’expĂ©rience d’autre part, dans l’émergence de rĂ©ponses sensorielles et fonctionnelles du cortex occipital. D’une part, l’observation de rĂ©ponses occipitales Ă  la stimulation auditive chez le non-voyant prĂ©coce (rĂ©organisation transmodale) rend compte de la capacitĂ© du cortex occipital Ă  rĂ©orienter sa modalitĂ© sensorielle prĂ©fĂ©rentielle en fonction de l’expĂ©rience. D’autre part, l’existence de modules cognitifs spĂ©cialisĂ©s dans le cortex occipital du non-voyant prĂ©coce, semblables Ă  ceux du cerveau voyant, dĂ©montre les contraintes intrinsĂšques imposĂ©es Ă  une telle plasticitĂ©. Dans une Ă©tude de cas longitudinale, nous avons Ă©galement explorĂ© comment les changements plastiques associĂ©s Ă  la cĂ©citĂ© interagissent avec une rĂ©cupĂ©ration visuelle partielle Ă  l’ñge adulte. Nous avons rĂ©alisĂ© des mesures prĂ© et post-opĂ©ratoires auprĂšs d’un patient ayant rĂ©cupĂ©rĂ© la vision, en combinant les techniques comportementales ainsi que de neuroimagerie fonctionnelle et structurelle afin d’investiguer conjointement l’évolution de la rĂ©organisation transmodale et de la rĂ©cupĂ©ration des fonctions visuelles Ă  travers le temps. Nous dĂ©montrons que les changements structurels et fonctionnels caractĂ©risant le cortex occipital du non-voyant sont partiellement rĂ©versibles suite Ă  une rĂ©cupĂ©ration visuelle Ă  l’ñge adulte. De maniĂšre gĂ©nĂ©rale, ces recherches tĂ©moignent de l’importante adaptabilitĂ© du cortex occipital aux prises avec des changements drastiques dans l’expĂ©rience visuelle.The present Ph.D. work was dedicated to the study of experience-dependent brain plasticity associated with visual deprivation/restoration. In two cross-sectional studies involving the use of functional magnetic resonance imaging in a group of participants with congenital or early blindness (and in a control group of sighted participants), we attempted to characterize the way the occipital cortex - typically devoted to vision – reorganizes itself in order to process different auditory stimuli. We demonstrate that in case of early visual deprivation, distinct regions of the occipital cortex display a functional preference for specific non-visual attributes, maintaining a functional specialization similar to the one that characterizes the sighted brain. Such studies have shed new light on the role played by intrinsic constraints on the one side, and experience on the other, in shaping the modality- and functional tuning of the occipital cortex. On the one hand, the observation of occipital responses to auditory stimulation (crossmodal plasticity) highlights the ability of the occipital cortex to reorient its preferential tuning towards the preserved sensory modalities as a function of experience. On the other hand, the observation of specialized cognitive modules in the occipital cortex, similar to those observed in the sighted, highlights the intrinsic constraints imposed to such plasticity. In a longitudinal single-case study, we further explored how the neuroplastic changes associated with blindness may interact with the newly reacquired visual inputs following partial visual restoration in adulthood. We performed both pre- and post-surgery measurements in a sight-recovery patient combining behavioral, neurostructural and neurofunctional methods in order to jointly investigate the evolution of crossmodal reorganization and visual recovery across time. We demonstrate that functional and structural changes evidenced in the visually-deprived occipital cortex can only partially reverse following sight restoration in adulthood. Altogether, our findings demonstrate the striking adaptability of the occipital cortex facing drastic changes in visual experience

    Curiosity and experience design: developing the desire to know and explore in ways that are sociable, embodied and playful

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    Curiosity, as a strong motivator for exploration and discovery, has long been an underexplored but important emotional response in relation to technology. This research considers that it has great potential to improve many aspects of the user experience, especially in today’s screen-saturated context. However, engaging curiosity by novelty and uncertainty may exhaust attentional strength and challenge usability. Thus, the purpose of this research is to find ways to foster the human trait of curiosity and avoid its negative effects. To gain an in-depth understanding of curiosity, the first chapter reviews cross-disciplinary literature to expand its role in improving user experience. This ranges from serving as an attention grabber to including the values that contribute to human survival, thriving, emotional resilience, and personal development. The second chapter identifies problems in the current curiosity-provoking design methods. The chapter also emphasises design for supporting active curiosity and avoiding the creation of purely novel stimuli. This approach is to encourage active curiosity to develop. To this end, the research proceeds to conduct observational studies at a museum to broaden our understanding of factors that influence people’s curiosity and exploration within a screen-mediated context. Based on these observations, I identified that there are three conceptual elements: sociability, embodiment, and playfulness. Through theoretical discussion and reflection upon the design examples, subsequent three chapters explore the relationship between curiosity and each conceptual element. The chapters also suggest several design approaches that embrace curiosity in relation to its social, embodied, and playful nature. These include creating a sense of co-curiosity, allowing the use of covert and overt curiosity-satisfying strategies, increasing bodily exploration affordances of the screen for linking curiosity with embodiment, using metaphors of the body-screen relationship, and developing possibilities and adding enchanting effects for eliciting playfulness to enrich curiosity. In essence, this research enhances our understanding of the user experience from the perspective of curiosity, and these design suggestions also help to embrace users’ active curiosity in developing sociable, embodied, and playful well-being in the age of ubiquitous screens
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