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École Doctorale Neurosciences et Cognition (NSCo)

Overview
Works: 290 works in 296 publications in 2 languages and 301 library holdings
Roles: Other, Degree grantor
Publication Timeline
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Most widely held works by École Doctorale Neurosciences et Cognition (NSCo)
Regulation of perceptual learning by mindfulness meditation : experiential and neurophysiological evidence by Enrico Fucci( )

1 edition published in 2018 in English and held by 5 WorldCat member libraries worldwide

Due to its widespread implementation in clinical settings, the neuroscientific study of mindfulness meditation has seen a rapid growth in the last two decades. Despite the evidence of changes in brain activity and structures, the neurocognitive mechanisms underlying meditation practices are largely unknown. In this work, we investigated the hypothesis that mindfulness meditation entails a cognitive stance towards experience which impacts the formation of mental habits. With this aim, we studied the relationship between the phenomenology of different styles of mindfulness meditation, in expert and novice practitioners, and neurophysiological markers of perceptual learning (i.e. auditory mismatch negativity) and attention in neutral and emotional settings. We found that a nondual style of mindfulness meditation increased sensory monitoring and reduced perceptual learning compared to a focused attention practice. Additionally, we demonstrated that auditory perceptual learning is not affected by unpredictable threat, except for individuals with high dispositional anxiety; an effect that might be downregulated by meditation states. Finally, we identified components of the auditory evoked response as putative neural correlates of monitoring processes during mindfulness practices and we highlighted a direct link between changes in subjective experience and emotion regulation in expert practitioners.Overall, the present work fosters the dialogue between cognitive neuroscience and phenomenological models of meditation and provides evidence of the possible neurocognitive mechanisms underlying meditation practices and expertise
Métrologie sensorielle olfactive et apprentissage olfactif appliqués à l'œnologie by Sophie Tempère( Book )

2 editions published in 2010 in French and held by 3 WorldCat member libraries worldwide

The quality of a wine is measured primarily by experts who evaluate its organoleptic features. Their olfactory and gustatory capacities are decisive, but these experts do not appreciate their own sensory abilities. Moreover, although we can give a clear definition of the expertise, several studies have shown that professionals are often confronted with disparities in their wine assessment. Several studies have also shown the differences between experts and novices, but no attention was paid to the diversity of the chemosensory abilities of the experts.At the Oenology Faculty in Bordeaux, with voluntary participation of the professionals, we characterized the olfactory performances of wine professionals and measured their impact on the wine assessment.The results showed significant inter-individual variation in olfactory sensitivities, hedonic ratings and cognitive abilities among the wine professionals. Further, our experiments have suggested that these inter-individual differences, especially concerning the sensitivity and the hedonic appreciation, influence perceptions and judgments of a same wine by the experts. However, the results confirm the possible influence of the cognitive dimensions related to the experience of the subject on their perception and their olfactory training. Finally, this work identifies training needs. We therefore propose and test practical tools for assessment of sensory performances and appropriate sensorial training. This has been an opportunity to highlight the potential role of attention or olfactory mental imagery in the improvement of the olfactory performance
Bases cellulaires et moléculaires de l'apprentissage et de la mémorisation dans le bulbe olfactif de souris by Germain Busto( Book )

2 editions published in 2009 in French and held by 2 WorldCat member libraries worldwide

My research was about cellular and molecular mechanisms implicated in olfactory learning and memory in the adult mouse olfactory bulb (OB). The OB is the first relay of olfactory information in the central nervous system. At this level, phenomenon of local plasticity could be involved in the conservation of a memory trace associated with learning process. First, I evaluated in the granule cell layer, the consequences of an olfactory associative learning on the IEG Zif268 odour-induced expression. Mice with a prior behavioural experience with the odour do not show increase in Zif268 expression. However, the specific odour-induced Zif268 expression pattern is modified by learning. Then, I isolated using laser capture microdissection activated cell populations of the granule cell layer, based on Zif268 expression patterns, after an olfactory associative learning. In those regions, I studied gene expression at a large scale. I found that neurotrophine pathway was modulated during the early phase of learning process whereas molecular actors of LTP are modulated during the consolidation phase. Finally, I showed that Zif268 knock-out mice exhibit associative learning and memory deficits. Those mice also present deficits to discriminate between closely related odorants. Those results indicate that acquisition by odorant of a behavioural meaning during olfactory learning modify odorant processing at the level of OB. Moreover we identified candidate genes that could be implicated in the cellular modifications
Étude des réseaux neuronaux et des mécanismes cognitifs impliqués dans les déficiences intellectuelles liées au chromosome X by Aurore Curie( Book )

2 editions published in 2011 in French and held by 2 WorldCat member libraries worldwide

Thanks to progress in molecular genetics, that allowed identification of new genes responsible for X linked intellectual disability, we studied on homogeneous groups of patients presenting with a mutation in one or the other gene. In the first section, we showed dysfunction of cerebello-thalamo-prefrontal networks, thanks to morphological MRI study performed on patients with a mutation in the Rab-GDI gene. In the second section, we highlighted a very specific phenotype related to ARX gene mutations, clinically, neuropsychologically, and kinematically, with a very peculiar impairment of upper limbs distal motricity, and language disorder. Patients hand-grip is pathognomonic, with a preference for the middle finger instead of the index for the grip of object, major impairment of fourth finger use, and lack of pronation movements. Neuroimaging study showed decreased volume of basal ganglia, and cortical thickness of motor regions, well correlated to kinematic parameters. In the third section, we explored reasoning strategies in three groups of patients with intellectual deficiency: fragile X, ARX mutated and Down syndrome patients and controls (both chronological and mental age-matched subjects). We notably elaborated a visual analogical reasoning paradigm, inspired from Raven's matrices. We established a developmental trajectory of this paradigm. The strategy used by patients (eyetracking study) was different from the one used by controls, with a huge lack of inhibition, even greater for fragile X patients than for Down syndrome patients
Modulation centrale du fonctionnement cochléaire chez l'humain : activation et plasticité by Xavier Perrot( Book )

2 editions published in 2009 in French and held by 2 WorldCat member libraries worldwide

The auditory system has two special features. At peripheral level, active cochlear micromechanisms (ACM), underlain by motility of outer hair cells (OHC), are involved in auditory sensitivity and frequency selectivity. At central level, the medial olivocochlear efferent system (MOCES), which directly projects onto OHC to modulate ACM, improves auditory perception in noise. From an exploratory point of view, both processes can be assessed through transient evoked otoacoustic emissions (TEOAE) and the procedure of contralateral suppression. In addition, experimental data in animals have disclosed a top-down control exerted by corticofugal descending auditory system (CDAS) on cochlea, via MOCES.The present work comprises three studies carried out in human, aiming to investigate interactions between CDAS, MOCES and ACM. The first and second studies, based on an innovative experimental procedure in epileptic patients undergoing presurgical stereoelectroencephalography, have revealed a differential attenuation effect of intracerebral electrical stimulation on TEOAE amplitude depending on stimulation modalities, as well as a variability of this effect depending on the clinical history of epilepsy. The third study has shown a bilateral enhancement of MOCES activity in professional musicians.Taking together, these results provide direct and indirect evidence for the existence of a functional CDAS in humans. Moreover, possible long-term plasticity phenomenon, either pathological -as in epileptic patients- or supernormal -as in professional musicians- may change cortico-olivocochlear activity
Monoxyde d'azote (NO) et trypanosomose africaine expérimentale chez le rat by Donia Amrouni( Book )

2 editions published in 2010 in French and held by 2 WorldCat member libraries worldwide

Grâce à un modèle expérimental de la trypanosomose humaine Africaine (THA ou maladie du sommeil), le rat infecté par Trypanosoma brucei brucei, nous avons examiné l'implication du monoxyde d'azote (NO) dans le développement de cette pathologie. Des variations opposées de la concentration de ce composé ont été observées chez les animaux infectés, au niveau des compartiments périphérique et central : le NO diminue au niveau du sang et augmente au niveau cérébral. Ces changements sont dépendants de la NO-synthase inductible (iNOS). Au niveau périphérique, la diminution du NO qui survient favorise l'installation du parasite car la pression trypanocide de ce composé est diminuée. Dans cette situation, la L-arginine, le substrat à la base de la synthèse du NO, est utilisée pour la synthèse de polyamines, des composés nécessaires à la croissance du parasite. Ces mécanismes sont très probablement déclenchés par le trypanosome via ses facteurs solubles. Au niveau cérébral, la synthèse du NO est aussi soumise à des régulations qui impliquent l'arginase et la NG, NG-diméthylarginine diméthylaminohydrolase (DDAH). Tandis que l'activité de l'arginase demeure constante, celle de la DDAH augmente au cours de l'infection en accord avec les données des western-blot et des amino-acides. Cette augmentation, qui dépend essentiellement de l'isoforme DDAH-2, conduit à une augmentation du NO cérébral dont les propriétés sont trypanocides. Ces changements, contraires à ceux observés en périphérie, sont défavorables à la survie du trypanosome au niveau du cerveau. Ils pourraient constituer une protection supplémentaire contre l'entrée des trypanosomes dans cet organe
A prefrontal-temporal network underlying state changes between Stimulus-Driven and Stimulus-Independent Cognition by Tomas Ossandon Valdes( Book )

2 editions published in 2010 in English and held by 2 WorldCat member libraries worldwide

The brain displays moment-to-moment activity fluctuations that reflect various levels of engagement with the outside world. Processing external stimuli is not only associated with increased brain metabolism but also with prominent deactivation in specific structures, collectively known as the default-mode network (DMN). The role of the DMN remains enigmatic partly because its electrophysiological correlates and temporal dynamics are still poorly understood. Using unprecedented wide-spread depth recordings in epileptic patients, undergoing intracranial EEG during pre-surgical evaluation, we reveal that DMN neural populations display task-related suppressions of gamma (60-140 Hz) power and, critically, we show how millisecond temporal profile and amplitude of gamma deactivation tightly correlate with task demands and subject performance. The results show also that during an attentional task, sustained activations in the gamma band power are presented across large cortical networks, while transient activations are mostly specific to occipital and temporal regions. Our findings reveal a pivotal role for broadband gamma modulations in the interplay between activation and deactivation networks mediating efficient goal-directed behavior
Auto-stigmatisation dans les troubles psychiques sévères et persistants by Julien Dubreucq( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Self-stigma is highly prevalent in persons with Serious Mental Illness (SMI) and is associated with poor patient's outcomes. Our objectives were a better understanding of self-stigma and how to reduce it trough improved clinical practice. This PhD dissertation has four steps : i) first, we reviewed the potential cognitive and neurobiological mechanisms underlying stigma and self-stigma ; ii) then we reviewed the prevalence, prédictors and correlates of self-stigma in SMI ; iii) we assessed the frequency of self-stigma and stigma resistance in the French national network of centres for psychiatric rehabilitation (REHABase), described in a previous article ; iv) we adapted in French Narrative Enhancement and Cognitive Therapy (NECT) self-stigma reduction program and initiated a stepped-wedge randomised control trial assessing its effectiveness in improving social function in SMI. Self-stigma is a major public health issue, affecting people in all geographical areas, all SMI conditions and all stages of the illness including at-risk states and early disorders. Elevated self-stigma concerned roughly one third of the participants included in the REHABase cohort. It was negatively associated with personal recovery, wellbeing and satisfaction in interpersonal relationships. Elevated stigma resistance concerned more than 50% of the participants and was positively associated with satisfaction in family relationships. The present dissertation has several implications for research and clinical practice, discussed throughly
From a Synthetic Auto-Biographical Memory toward the Emergence of Different Levels of Self : a Case Study with the iCub Humanoid Robot by Grégoire Pointeau( )

1 edition published in 2015 in English and held by 1 WorldCat member library worldwide

The objective of the following study is to define the influence of an Autobiographical Memory and its two main components : the Episodic Memory and the Semantic Memory in the emergence of the notion of “self”. I will focus on the functional part of the autobiographical memory rather that on its technical and neuronal aspect. Then I will describe the implementation of an synthetic autobiographical memory in an Humanoid Robot : the iCub. I will show how this synthetic autobiographical memory can participate with the help of several reasoning modules, in the emergence of the self. Concerning the aspect of self, we decided to work about Ulric Neisser's four components of the self described in 1995 : the Ecological Self, the Interpersonal Self, the Conceptual Self and the Temporally Extended Self
Modulation de la transmission synaptique dans les réseaux limbiques au cours du cycle veille-sommeil chez le rat by Julien Carponcy( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

Numerous studies have now demonstrated that sleep has a beneficial influence on memory but also impact forgetting. We have submitted rats to behavioral tasks involving different levels of forgetting. These tasks, implying reference memory (RM) or working memory (WM) with different level of interferences, were executed in the same behavioral apparatus. Whereas we observed an increase of paradoxical sleep (PS) during the RM training, the WM tasks requiring forgetting are dependent on slow-wave sleep (SWS). Only the RM trained rats exhibited an increase in theta bursts during PS, as well as spindles during SWS. These results thus indicate the role of PS in long-term spatial learning, whereas behavioral flexibility required by WM tasks is dependent on SWS. Numerous pieces of evidence suggest that learning is caused by modifications of synaptic connections, and different theories suggest different roles of the SWS and PS to optimize these changes. We sought to understand the evolution of synaptic transmission in the hippocampal network but also between the hippocampus (HPC) and the medial prefrontal cortex (mPFC), as well as between the HPC and the nucleus accumbens (NAc). While SWS increases synaptic transmission in the HPC, PS decreases it rapidly. In contrast and regarding hippocampal efferents, SWS reduces transmission to the mPFC while PS enhances transmission to the NAc. In contrast to the hypotheses posing that sleep promotes a global process common to the entire brain; our results suggest that SWS and PS redirect data flows between different networks, and that this switch between different information pathways could be modulated by the various sleep oscillations
Autoimmune neurological syndromes with anti- CASPR2 antibodies : clinical, immunological and genetic characterization by Bastien Joubert( )

1 edition published in 2019 in English and held by 1 WorldCat member library worldwide

Les auto-anticorps dirigés contre CASPR2 (Contactin-2 Associated Protein), une protéine d'adhésion neuro-gliale, ont été décrits dans au moins trois syndromes neurologiques auto-immuns: l'encéphalite limbique auto-immune, la neuromyotonie acquise et le syndrome de Morvan. Cependant, le phénotype clinique associé aux anticorps anti-CASPR2 demeure imparfaitement décrit. Ce travail de thèse vise à décire les présentations cliniques des patients avec anticorps anti-CASPR2. La première étude est consacrée à l'analyse de la présentation clinique et du pronostic de l'encéphalite limbique auto-immune à anticorps anti-CASPR2. Nous observons que la majorité des patients sont des hommes âgés de 50 à 75 ans, et ont fréquemment des symptômes extra-limbiques, en particulier une ataxie cérébelleuse. Ces patients répondent le plus souvent aux immunothérapies, bien qu'un quart des patients garde des séquelles cognitives, une épilepsie, ou une ataxie. Dans la seconde étude, nous décrivons pour la première fois l'ataxie épisodique auto-immune, un symptôme jusqu'ici exclusivement associé à l'encéphalite auto-immune avec anticorps anti-CASPR2. Ce symptôme est similaire aux ataxies épisodiques héréditaires et, de façon remarquable, nous avons décelé chez 2 patients un polymorphisme rare des gènes KCNA1 ou CACNA1A, qui sont impliqués respectivement dans l'ataxie épisodique de type 1 et de type 2. Bien que l'impact de ces variants rare sur la fonction des canaux ioniques qu'ils codent est inconnu, ces observations soulèvent la question de l'influence du terrain génétique sur la détermination du phénotype neurologique des patients avec anticorps anti-CASPR2. Dans la troisième étude, nous réalisons une analyse typologique des symptômes des patients dans le but de vérifier si les symptômes se distribuent de façon aléatoire ou au contraire forment des profils cliniques spécifiques. Par cette méthode, nous démontrons que les symptômes s'associent de façon non-aléatoire, permettant de classer les patients en trois groupes distincts, qui correspondent à l'encéphalite limbique auto-immune, à la neuromyotonie, et au syndrome de Morvan. De plus nous confirmons la grande variété de présentation clinique de l'encéphalite à anticorps anti-CASPR2, qui ne se limite pas à la présence de symptômes limbiques, puisque plus d'un tiers de patients présente également des symptômes extra-limbiques, tels que l'ataxie cérébelleuse, la dysautonomie, la perte de poids, ou des mouvements anormaux. De façon notable, moins de dix pour cent des patients avaient une combinaison de symptômes limbiques et de neuromyotonie. Enfin, le syndrome de Morvan se caractérise dans notre série par des signes sévères d'hyperexcitabilité nerveuse périphérique, des signes sévères de dysautonomie, une insomnie sévère, une perte poids fréquente, et une association au thymome malin. Cette classification clinique en trois syndromes est confortée par des variations des caractéristiques des auto-anticorps, puisque les patients avec une encéphalite limbique ont des titres sériques d'anticorps anti-CASPR2 plus élevés, et des anticorps anti-CASPR2 détectable plus souvent dans le liquide céphalo-rachidien, ainsi que par des différences en terme d'haplotype HLA associé, puisque les patients avec un syndrome de Morvan ne sont pas porteurs de l'haplotype HLA DRB1*1101 qui est retrouvé chez les patients avec une encéphalite limbique à anticorps anti-CASPR2. En conclusion, ce travail de thèse conforte la notion que les patients avec anticorps anti-CASPR2 présentent des syndromes spécifiques, l'encéphalite limbique, la neuromyotonie acquise, et le syndrome de Morvan. La variabilité clinique observée avec les anticorps anti-CASPR2 est vraisemblablement liée à l'existence de mécanismes physiopathologiques différents selon les syndromes
Stimulations spécifiques pour la rééducation de déficits moteurs : biomécanique et modélisation by Damien Laurent( )

1 edition published in 2011 in French and held by 1 WorldCat member library worldwide

We investigated the underlying mechanisms of an visuomanual adaptation experiment mimicking the well-known saccadic adaptation paradigm, described by [Magescas 2006a]. The first chapter aims at giving evidence that the [Magescas 2006a]'s paradigm induced little if any perceptual effects, which means it implicated the only phase of motor commands generation. The second chapter deals with the generalization process of adaptation at the level of one joint (the elbow). Our results suggest that the studied paradigm induced a focused change of the motor gain of the group of elbow extensor muscles. The third chapter details the development of methods to record the arm joint configuration. Such a methodology allowed to precisely compared the hypothesis of generalisation of adaptation in task space and in joint space. In chapter 4, following an explorative approach, we have designed two protocols transposing the [Magescas 2006a]'s experiment, in order to widen our ressources for a future research on patients with motor deficit. At the end of the present work, we have : methodological means of recording and of modeling the joint chain of the arm ; a theoretical model of the studied motor adaptation ; and a new protocol of adaptation of grasping, which is more convenient than adaptation of pointing for clinical purposes
Perception et apprentissage des structures musicales et langagières : études des ressources cognitives partagées et des effets attentionnels by Lisianne Hoch( )

1 edition published in 2010 in French and held by 1 WorldCat member library worldwide

Music and language are structurally organized materials that are based on combinatorial principles. Listeners have acquired knowledge about these structural regularities via mere exposure. This knowledge allows them to develop expectations about future events in music and language perception. My PhD investigated two aspects of domain-specificity versus generality of cognitive functions in music and language processing: perception and statistical learning.In the first part (perception), musical structure processing has been shown to influence spoken and visual language processing (Études 1 & 4), partly due to dynamic attending mechanisms (Jones, 1976). More specifically, musical structure processing has been shown to interact with linguistic-syntactic processing, but not with linguistic-semantic processing (Étude 3), thus supporting the hypothesis of shared syntactic resources for music and language processing (Patel, 2003). Together with previous studies that have investigated simultaneous musical and linguistic (syntactic and semantic) structure processing, we proposed that these shared resources might extend to the processing of other structurally organized information that require structural and temporal integration resources. This hypothesis was tested and supported by interactive influences between simultaneous musical and arithmetic structure processing (Étude 4). In the second part (learning), statistical learning was directly compared for verbal and nonverbal materials. In particular, we aimed to investigate the influence of dynamic attention driven by non-acoustic (Études 5 & 6) and acoustic (Étude 7) cues on statistical learning. Non-acoustic temporal cues have been shown to influence statistical learning of verbal and nonverbal artificial languages. In agreement with the dynamic attending theory (Jones, 1976), we proposed that non-acoustic temporal cues guide attention over time and influence statistical learning.Based on the influence of dynamic attending mechanisms on perception and learning and on evidence of shared structural and temporal integration resources for the processing of musical structures and other structured information, this PhD opens new questions about the potential influence of tonal and temporal auditory structure processing on general cognitive sequencing abilities, notably required in structured sequence perception and learning.Jones, M. R. (1976). Time, our lost dimension: Toward a new theory of perception, attention, and memory. Psychological Review, 83(5), 323-355. doi:10.1037/0033-295X.83.5.323Patel, A. D. (2003). Language, music, syntax and the brain. Nature Neuroscience, 6(7), 674-681. doi:10.1038/nn1082
Effets des émotions sur la mémoire épisodique chez l'enfant au développement typique et dans le syndrome de Williams-Beuren : approche comportementale et neurophysiologique by Sarah Massol( )

1 edition published in 2021 in French and held by 1 WorldCat member library worldwide

In the last few years, emotions and cognition, and in particular the link between the two, have fascinated scientists around the world, giving rise to a large body of research in psychology, cognitive science and neuroscience. One of the cognitive functions that has drawn the attention of researchers, in line with its emotional modulation, is episodic memory. Thus, research work carried out in humans has largely agreed on one point: emotions improve episodic memory, a phenomenon which is called Emotional Enhancement of Memory (EEM). While the EEM has been extensively investigated in the adult population, the nature of the interaction between memory and emotions remains largely unexplored during development. However, childhood is a critical period during which major changes emerge in brain function, underpinning the cognitive and emotional development of children until adulthood. This thesis work therefore focused, primarily, on the study of the EEM in typically developing (TD) children in order to highlight potential developmental modulations compared to the adult population. Secondly, in order to broaden our knowledge of the EEM during development, this thesis work adopted a neuropsychological approach with the study of this phenomenon in children and adolescents with a neurodevelopmental disorder called Williams-Beuren syndrome (WBS). Thus, several experimental studies were conducted in order to evaluate the EEM in TD children and individuals with WBS, both with behavioral assessments, including encoding and retrieval tasks of emotional (negative and positive) and neutral stimuli, as well as with neurophysiological measures using electroencephalography (EEG). In particular, the behavioral evaluations examined episodic memory as a whole, taking into account its two main components, i.e. item memory and associative memory. The results obtained in this research work highlighted, for the first time, the emergence of an EEM in both item and associative memory in TD children aged 8 to 11 years, which is similar to that of young adults. First clues of the modulation of neural responses during the encoding of emotional stimuli that can predict behavioral memory performance were also shown in TD children. In addition, this research work provided the first evidence of the emergence of an EEM in children and adolescents with WBS aged 8 to 18 years, which appeared similarly to a group of young TD children. Overall, this thesis work helped to demonstrate that EEM is a robust phenomenon, established early in development and which does not seem to be affected by the immaturity of certain memory processes in TD children, nor by the alteration of these processes in the case of WBS
Dimension sociale de l'espace péri-personnel des primates by Audrey Dureux( )

1 edition published in 2021 in French and held by 1 WorldCat member library worldwide

Même si nous percevons l'espace qui nous entoure comme un continuum cartésien, la région de l'espace près du corps où se déroulent les interactions physiques avec l'environnement est une région spéciale, appelée espace péri-personnel (EPP). L'EPP a d'abord été défini sur la base des propriétés de neurones enregistrés chez le singe dans des régions cérébrales prémotrices et pariétales spécifiques. Plus récemment, un réseau homologue putatif a été identifié chez l'homme en utilisant l'IRMf. La représentation de cet espace ne fait pas référence à une région bien délimitée avec des frontières claires mais est au contraire flexible, nous permettant d'adapter notre comportement en fonction du contexte. En particulier, le monde des hommes et des singes est avant tout un monde social. Dans ce monde social, une zone de confort est nécessaire pour réguler la distance entre soi et les autres et ainsi éviter l'inconfort, voire l'anxiété. Cependant, on sait encore peu de choses sur cette dimension sociale de l'EPP comparé à celle liée aux objets. Dans ce contexte, mon travail de thèse visait d'abord à combler le fossé entre les propriétés enregistrées dans les neurones individuels du singe et les activités cérébrales identifiées en neuroimagerie du réseau prémoteur-pariétal humain. Deuxièmement, il visait à apporter un nouvel éclairage sur la dimension sociale de l'EPP, un sujet qui a été largement négligé jusqu'à présent alors qu'il est de la plus haute importance pour tous les animaux. Pour répondre à ces questions, j'ai développé des protocoles utilisant un environnement de réalité virtuelle (RV) permettant une manipulation et un contrôle très précis des informations visuelles à différentes distances de notre corps. Pour réaliser mon premier objectif, j'ai utilisé des procédures expérimentales similaires chez l'homme et le singe afin de comparer l'activité cérébrale en IRMf. À travers deux tâches, où des objets réels ou virtuels étaient présentés à différentes distances (proche et éloignée) du corps, j'ai identifié un réseau prémoteur-pariétal homologue sous-jacent à la représentation de l'EPP chez les deux espèces. Pour réaliser mon deuxième objectif, j'ai utilisé une approche multi-échelle. Plus précisément, mon objectif était de comprendre comment les informations sociales (expressions faciales émotionnelles) dans notre EPP affectent nos capacités de perception, notre état physiologique, et notre activité cérébrale. Au niveau comportemental, mes résultats ont montré que nos capacités de discrimination visuelle étaient améliorées lorsque les visages émotionnels étaient présentés dans l'EPP par rapport à l'espace lointain, même lorsque la taille rétinienne était similaire pour les images proches et lointaines. Cette amélioration des capacités perceptives s'accompagnait d'une augmentation de la fréquence cardiaque lorsque les visages émotionnels étaient proches du corps. Enfin, au niveau neuronal, j'ai identifié un réseau occipito-prémoteur-pariétal avec une activité accrue en présence de visages émotionnels proches par rapport aux visages lointains. Mes résultats montrent également qu'un réseau commun code de manière similaire des stimuli sociaux et non sociaux dans l'EPP. Parallèlement à ce travail réalisé chez des volontaires sains, j'ai également établi un lien direct entre des lésions unilatérales médio-temporales et un déficit dans la régulation appropriée des distances sociales. En résumé, mes résultats démontrent que la présence sociale dans l'EPP facilite nos performances comportementales, augmente notre niveau de vigilance et recrute un réseau neuronal prémoteur-pariétal central quelque soit le type d'information (sociale ou non sociale). Ainsi, un réseau neuronal commun permettrait une réponse rapide, qui pourrait être principalement recruté dans n'importe quelle situation se produisant dans notre EPP, et des régions cérébrales supplémentaires pourraient entrer en jeu afin d'affiner notre comportement en fonction du contexte
Effets de l'âge et de la maladie de Parkinson sur la marche : approche neurophysiologique by Isabelle Hoang( )

1 edition published in 2021 in French and held by 1 WorldCat member library worldwide

With aging and the onset of neurodegenerative diseases such as Parkinson's disease, cog-nitive and motor disorders can appear and have repercussions on the activities of daily living. Walking disorders and consequently the risk of falling, in normal and pathological aging, rep-resent a major public health issue. Among the factors that can explain these disorders, pre-frontal activity during walking in aging and Parkinson's disease has been relatively little inves-tigated. The objectives of this thesis were to: 1) better understand the changes in prefrontal ac-tivity during walking with advancing age and in the presence of Parkinson's disease and 2) determine to which extent an intensive physical rehabilitation program could modify prefron-tal activity in these pa-tients. To address the first objective, 93 participants divided into 4 groups (young adult, young-est-old adults, older adults, and Parkinson's disease patients) were included. Prefrontal ac-tivity was measured using functional Near Infrared Spectroscopy (fNIRS) during different walk-ing tasks vary-ing in complexity. To address the second objective, prefrontal activity during walking was measured before and after an intensive exercise-based rehabilitation program in patients with the same de-vice. The results show a progressive increase in prefrontal activity with age and Parkinson's disease. This increase is present as early as 55 years of age in single-task walking condition, without alteration of walking performance compared to young adults. This may reflect a greater demand on executive resources to perform the walking task. However, in the dual-task condition, older individuals and patients show prefrontal overactivation, associated with poorer walking performance. This sug-gests that older adults and patients are no longer able to effectively compensate for age-related deficits to perform the dual-task walking. After an intensive rehabilitation program, prefrontal ac-tivity during single-task walking decreased in Parkinson's patients, indicating a decrease in the de-mand for executive resources and thus a gain in the automaticity of walking performance. In conclusion, this thesis work allows us to better understand the neurophysiological modifications with advancing age and Parkinson's disease. From a clinical point of view, this work could also help to identify people at risk of falling earlier
Étude de la régulation de la concentration extracellulaire de D-sérine et de son implication dans l'excitotoxicité by Caroline Maucler( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

La D-sérine, co-agoniste endogène du récepteur N-Méthyl D-Aspartate, est impliquée à la fois dans des fonctions physiologiques telles que l'apprentissage et le vieillissement et dans des pathologies psychiatriques et neurodégénératives comme la schizophrénie ou la sclérose latérale amyotrophique. Ce travail de thèse est composé de deux parties. Premièrement, je me suis intéressée aux mécanismes de régulation de la D-sérine extracellulaire. A l'aide de biocapteurs enzymatiques développés au laboratoire, nous avons évalué, in vivo, la diffusion de la D-sérine à travers la barrière hématoencéphalique et estimé sa concentration dans différents compartiments. Nous avons aussi montré que la recapture de la D-sérine est assurée par les transporteurs de type ASC et que sa dégradation est effectuée par la D-amino acide oxydase dans le cervelet et par la sérine racémase dans le cortex. Deuxièmement, j'ai étudié l'implication de la D-sérine dans le status épilepticus, un modèle présentant une forte excitotoxicité avérée. Nous avons tout d'abord développé une méthode de comptage automatique pour quantifier précisément la mort neuronale. Puis nous avons enregistré les concentrations de D-sérine et de glutamate extracellulaires lors du status épilepticus et nous avons montré que ces deux transmetteurs ont leur concentration augmentée dans le cortex piriforme/amygdale, zones fortement touchées par l'excitotoxicité. En revanche dans le cortex où il n'y a pas de perte neuronale excitotoxique, leur concentration reste inchangée. Mieux comprendre la régulation de la D-sérine et son rôle pathologique est essentiel pour développer et adapter des traitements
Perception visuelle et olfactive chez les enfants avec un trouble du spectre de l'autisme : implications sur l'acceptation des aliments by Anne-Claude Luisier-Maret( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

The development of eating behaviour is a complex phenomenon in a majority of children with Autism Spectrum Disorder (ASD). This doctoral thesis aims to better understand the extent to which perceptual particularities (visual and olfactory) in children with an ASD influence their acceptance of a food.Our results show that ASD children differ on a sensorial level from Typically developed (TD) children, these differences depending on the nature of the stimuli (vision and olfaction). They also attribute a lower valence to stimuli which are, a priori, pleasant. This was particularly true for visual stimuli. Finally, we observe a link between hedonic judgement and the degree of neophobia in children with an ASD. This was not the case in TD children.Next, we evaluated the effects of olfactory familiarisation on the valence of an odour. Our results show an increase in positive emotional expression relating to the smell which has been familiarised. We also observed that two thirds of the children, notably those with the most sensory particularities, chose the food that carried this odour.The final objective of this thesis was to consider the perspectives of ASD children and to compare them with results obtained in neuroscience. Our observations highlight the relevance of establishing a dialogical research and/or support approach that allows us to build and develop our knowledge of food and eating. Our studies underline the importance of considering the perceptual profiles of ASD children when designing educational tools to support eating behaviour development
L'inextricable relation olfaction-respiration chez le rat : études de l'impact des variations de flairages sur l'activité du bulbe olfactif et sur la discrimination des odeurs by Emmanuelle Courtiol( )

1 edition published in 2012 in French and held by 1 WorldCat member library worldwide

In terrestrial mammals, an inextricable link between olfaction and respiration exists due to the periodic sampling of odorant molecules by inhalation. The features of sniffing (or breathing) constrain both the timing and the intensity of the input to the olfactory structures. But rather than being fixed, sniffing in the bahavingrodent is highly dynamic and varies both in frequency and flow rate. During the firs stage of my PhD, I asked to what extent sniffing parameters (frequency and flow rate) variations could affect the olfactory bulb activity. To address this question, I developped a double tracheotomy protocol in anesthetized rats to precisely control and modify the nasal airflow. In parallel, I recorded oldfactory bulbactivities, single-unit activity and local field potentials. We showed that, at the olfactory bulb level, the neutral representation of an odor is highly modified by sampling variations. In fact both the mitral/tufted cell discharge patterns and local field potentials oscilliations were affected by sniffing variations. In the second stage, we wanted to understand the role of sniffing variations in behaving animals. We hypothesized tha t an animal could adapt its sniffing strategy relative to the quality of the odorant molecules. To test this hypothesis, we developped a tool to record sniffing in a non invasive way, and combined it to an olfactory discrimination task in the rat. We showed that animals not only adapted their sniffing relative to the odorant quality but also to the odorant context. Taken together, these results fit into the broader context of sensory-motor integration
L'électrophysiologie temps-réel en neuroscience cognitive : vers des paradigmes adaptatifs pour l'étude de l'apprentissage et de la prise de décision perceptive chez l'homme by Gaëtan Sanchez( )

1 edition published in 2014 in English and held by 1 WorldCat member library worldwide

Today, psychological as well as physiological models of perceptual learning and decision-making processes have recently become more biologically plausible, leading to more realistic (and more complex) generative models of psychophysiological observations. In parallel, the young but exponentially growing field of Brain-Computer Interfaces (BCI) provides new tools and methods to analyze (mostly) electrophysiological data online. The main objective of this PhD thesis was to explore how the BCI paradigm could help for a better understanding of perceptual learning and decision making processes in humans. At the empirical level, I studied decisions based on tactile stimuli, namely somatosensory frequency discrimination. More specifically, I showed how an implicit sensory context biases our decisions. Using magnetoencephalography (MEG), I was able to decipher some of the neural correlates of those perceptual adaptive mechanisms. These findings support the hypothesis that an internal perceptual-reference builds up along the course of the experiment. At the theoretical and methodological levels, I propose a generic view and method of how real-time electrophysiology could be used to optimize hypothesis testing, by adapting the experimental design online. I demonstrated the validity of this online adaptive design optimization (ADO) approach to maximize design efficiency at the individual level. I also discussed the implications of this work for basic and clinical neuroscience as well as BCI itself
 
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Alternative Names
Ecole Doctorale NSCo

ED 476

NSCo

Languages
French (20)

English (6)