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Fast neural dynamics of a frontoparietal ‘multiple demand’ network during task-switching| old_uid | 15362 |
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| title | Fast neural dynamics of a frontoparietal ‘multiple demand’ network during task-switching |
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| start_date | 2015/03/23 |
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| schedule | 11h30 |
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| online | no |
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| location_info | Bât. 452, Bibliothèque |
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| details | Séminaire CRNL-DYCOG |
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| summary | The fast neural dynamics of task-specific and domain-general mechanisms subserving cognitive flexibility are still ill defined. In this study, event-related potentials (ERPs) were recorded from 36 participants while they were intermittently cued to switch or repeat their perceptual categorization of Gabor gratings varying in color and thickness (Switch task), or else they performed two visually identical control tasks (NoGo and Oddball). Our task cueing paradigm was designed to examine proactive and reactive control modes during both cue-locked rule preparation and target-locked rule implementation stages. Unlike past studies, we addressed trial-by-trial dynamics of sensorimotor, contextual and episodic control operations ensuing task transition points. Both switch-specific (indexed by cue-locked P600 and a sustained target-locked positivity following task transitions) and domain-general mechanisms (indexed by cue- and target-locked P2 and P3 ERP components) revealed fast recurrent modulations of neural activity within a common frontoparietal network. Topographic analyses of normalized brain responses revealed distinct split-second swings of activation across posterior and frontal scalp regions as a function of increasing cognitive demands and proactive vs. reactive control modes. Modulations of domain-general brain potentials paralleled predictions from information theoretic models (Koechlin & Summerfield, 2007) that envisage cognitive control as a series of temporarily ordered processing stages at various levels within a hierarchy of representations (e.g., sensory, contextual, episodic) in the brain. These results suggest distinct functional roles for the fast and recursive activations observed within a frontoparietal “multiple demand” system (Duncan, 2013) during the preparation and implementation stages of task switching. |
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| responsibles | Béranger, Rossetti |
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