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This study aims to understand the role of verbal and visual-spatial components of working memory in children's encoding of virtual routes. Children aged 8 and 10 years and adults memorised virtual routes in three conditions involving either a secondary task (visuo-spatial or verbal) or no such task (control). The learning phase was followed by four tasks evaluating their spatial representation: producing a description of the route, verbally and visually recognising landmarks, and choosing directions. Results first supported an increase with age in the quantity and quality of landmarks and directions mentioned and recognised in both verbal and visuo-spatial tasks. Second, both concurrent tasks were detrimental to spatial memory although this was more striking for the visuo-spatial task. Moreover, interference effects depended on age and on the format used for retrieval. Overall, our results provide a novel contribution to our understanding of the development of spatial models.

International audience

International audience; SET is a multifunctional protein, but when present in the cytoplasm, acts as a powerful inhibitor of phosphatase 2A. We previously observed that in CA1 of Down syndrome (DS) patients, the level of SET is increased, and SET is translocated to the cytoplasm and associated with the hyperphosphorylation of tau at ser202/thr205. The presence of SET in the cytoplasm in DS brains may play a role in the progression of the disease. Here, we show that in CA1 of 3-month-old Ts65Dn mice modeling DS, SET level is increased, and SET is translocated to the cytoplasm and associated with tau hyperphosphorylations at ser202/ thr205 and with amyloid precursor protein caspase cleaved as observed in Alzheimer disease brains. Tau hyperphosphorylation at ser356 and activation of other phosphatase 2A targets such as the mammalian target of rapamycin and adenosine monophosphate protein kinases were also observed, suggesting deleterious mechanisms. We propose Ts65Dn mice as a model for therapeutic approaches focused on SET overexpression and its cytoplasmic translocation to slow down disease progression.

International audience; Anorexia nervosa (AN) is classically defined as a condition in which an abnormally low body weight is associated with an intense fear of gaining weight and distorted cognitions regarding weight, shape, and drive for thinness. This article reviews recent evidences from physiology, genetics, epigenetics, and brain imaging which allow to consider AN as an abnormality of reward pathways or an attempt to preserve mental homeostasis. Special emphasis is put on ghrelino-resistance and the importance of orexigenic peptides of the lateral hypothalamus, the gut microbiota and a dysimmune disorder of neuropeptide signaling. Physiological processes, secondary to underlying, and premorbid vulnerability factors—the “pondero-nutritional-feeding basements”- are also discussed.

This exploratory study aims to achieve a better understanding of the users-related factors that affect the choice of routes in public transport (PT). We also look at what can motivate route and modes changes towards alternatives in a real situation. We investigated the experience of 19 users of PTs, using the critical incident technique (Flanagan in Psychol Bull 51(4):327, 1954). We asked participants to report incidents (i.e. situations) in cases they were very satisfied or dissatisfied with their choice. For both situations, the case of their usual route and case of an alternative were considered. A total of 91 incidents were collected and analysed using a multiple correspondences analysis. Additionally, users' profiles were characterized and superposed to the analysis of incidents content. The main results are as follows. First, the user's choice of PT route depends on the context (i.e. aim of the travel, time of day). Second, taking an alternative to the usual PT route or using a route combining different transport modes is determined by the context and by factors related to the pleasantness of the travel (e.g. to accompany a friend along the travel). Finally, depending on the user's profile (i.e. combination of attitude towards PT and demographic variables), the factors taken into account to make the choice of a PT route are related to the efficiency or the pleasantness of the trip. These results show the importance of the contextual factors and the users' profiles in route choice. They suggest that these factors should be further taken into account in new tools and services for mobility.

Route planning is an everyday task performed when we want to travel. Even though it is a routine task, researches in problem-solving and spatial cognition domains have revealed that various strategies and cognitive resources are involved (e.g. working memory, spatial abilities, and executives' functions). Some models have been proposed to explain the formation of travel plans. They usually describe the planning process into different stages with or without competition between strategies (Gärling, Säisä, Böök & Lindberg, 1986, Cuntini, Di Fernando, Basso, Bisiacchi & Zorzi, 2008). More ecological studies, i.e. in real situations, have shown the implication of additional factors such as selection criteria, personal and contextual variables. To date however, few studies have taken an interest on the route planning using public transport, even though promote these modes is necessary considering environmental concerns and saturation of traffic in large cities. A question is whether planning and choice processes are modified due to special features of public transports (various modes and changes of modes) and which are the cognitive, psycho-social and contextual factors involved. To answer this question, we conducted four studies to investigate different dimensions of public transport planning activity using various methodologies and paradigms as eye-tracking (study 1), interview (study 2), two alternatives forced-choice (study 3) and virtual reality (study 4). The outcomes of these studies are that the route planning from a network map is a two-step process which becomes more complex with the number of changes of lines (study 1). The analyses of users' experience (study 2) and of different simulations (studies 3 and 4) show that the route choice depends both on the context and the user's profile (spatial abilities, preferences, attitudes, etc.). Results allow us to propose recommendation to better adapt assistance depending on various users profiles, in order to favour the use of public transports. Finally, on the theoretical side, our studies highlight that taking into account only the cognitive facet to build route-planning models is not sufficient, while considering different users' profiles provides a more complete picture of the processes involved.; Planifier un itinéraire est une tâche réalisée quotidiennement pour nos déplacements. Bien que cette tâche soit routinière, les recherches dans le domaine de la résolution de problème et de la cognition spatiale ont révélé les stratégies adoptées et les ressources cognitives (e.g. mémoire de travail, capacités spatiales, fonctions exécutives) nécessaires à sa réalisation. Ainsi différents modèles cognitifs décrivant la planification en différentes étapes avec ou sans compétition entre stratégies ont été proposés pour expliquer la formation des plans de voyage (Gärling, Säisä, Böök & Lindberg, 1986, Cuntini, Di Fernando, Basso, Bisiacchi et Zorzi, 2008). L'étude plus écologique de la planification, c’est-à-dire en situation réelle, montre la mise en jeu de facteurs supplémentaires tels que les critères de sélection, des facteurs individuels et contextuel. Cependant à ce jour peu d'études se sont intéressées à la planification d'itinéraire en transports en commun, alors que la valorisation de ces modes est actuellement nécessaire pour répondre aux préoccupations environnementales et de congestion du réseau routier des grandes villes. Dès lors, une question est de savoir si les processus de planification et de choix d’itinéraires sont modifiés du fait de la spécificité des itinéraires en transports en commun (modes variés et changements de modes) et quelles sont les facteurs cognitifs, psycho-sociaux, et contextuels impliquées. Pour répondre à cette question, nous avons mené quatre études pour investiguer différentes dimensions de cette activité à l'aide de paradigmes et techniques variés telles que les mouvements oculaires (étude 1), l'entretien (étude 2), des choix forcés (étude 3) et la réalité virtuelle (étude 4). Ces études ont permis de mettre en évidence que la planification d'itinéraire à partir de cartes de réseaux de transports s'effectue en deux temps et qu'elle se complexifie avec l'augmentation du nombre de changements de lignes (étude 1). De plus, l'analyse de l'expérience des usagers (étude 2) et les résultats de mises en situations expérimentales (études 3 et 4) ont montré que le choix d'itinéraire dépend du contexte et du profil de l'usager (capacités spatiales, préférences, attitude, etc.). Les résultats permettent donc de proposer des préconisations pour adapter les aides à la planification en considérant les différents profils d'usagers afin de favoriser l'utilisation de ces modes. Enfin, sur le plan théorique, nos études montrent que la prise en compte uniquement de l'aspect cognitif pour modéliser la planification n’est pas suffisante et que considérer les différents profils d'usagers permet une modélisation plus complète de ce processus complexe.

Although many studies have investigated spatial representation in young adults, little is still known about the processes underlying how they construct spatial models, the nature of these models, and how they develop in children. The originality of this thesis is two-fold: it studies both cognitive and linguistic processes involved in how children (5 to 11 years) and adults construct representation of virtual routes; it also examines individual differences in these processes.The first part of this thesis begins with a chapter that presents the main concepts underlying spatial cognition, as well as some experimental evidence concerning adults’ spatial knowledge and the development of this knowledge during childhood. A second chapter then focuses on the role of language and a third one on the role of working memory in the construction of spatial representations.In order to understand how children construct spatial representation during development, a second part of the thesis presents three experiments investigating the development of landmark and route knowledge. The first two studies show developments in the quality and quantity of knowledge concerning both landmarks (i.e. specific entities encountered along the route) and the route (i.e. the sequential order of actions and landmarks). They also provide evidence supporting the specific role of landmarks associated with changes of direction (“decisional” landmarks) in children and adults. Developmental changes in spatial knowledge were assessed by both verbal and non-verbal measures, suggesting the existence of a unique representation or of two representations that are strongly related. The relation between verbal and non-verbal information in participants’ representations is evidenced by their bias toward choosing a related landmark of the same semantic category, regardless of its visual characteristics. Nevertheless, analyses show that visuo-spatial abilities such as the perception of directions, but not verbal abilities, play a main role in accounting for individual differences. The third study, investigates verbal and visuo-spatial components of working memory, using a dual task paradigm in which participants performed a verbal or spatial interference task while memorizing routes. The results support the idea that representing itineraries mostly involves a spatial mode of encoding in children and a more verbal or mixed encoding in adults.To conclude, this thesis shows a development in children’s capacity to build spatial representations of virtual routes. Although their representation seems to integrate both verbal and non-verbal components, non-verbal abilities appear to be most essential for children. The last part of the thesis discusses the implications of our results for our understanding of the development of spatial cognition in children, as well as future perspectives and conclusions., Si de nombreux travaux ont été consacrés aux représentations spatiales chez le jeune adulte, la nature des modèles spatiaux, les processus qui président à leur construction et la façon dont ils se développent sont encore loin d’être compris. L’originalité de cette thèse tient au fait d’étudier conjointement les composantes cognitives et langagières dans l’acquisition des représentations d’itinéraires virtuels par des enfants (de 5 à 11 ans) et des adultes, ainsi que les différences individuelles liées à des capacités générales variées.Dans une première partie, la thèse présente les principaux concepts de la cognition spatiale issus des travaux menés chez l’adulte ainsi que l’état des connaissances théoriques et empiriques actuelles sur le développement des représentations spatiales chez l’enfant. Un chapitre s’intéresse ensuite au rôle du langage dans la construction des représentations spatiales et un autre à celui de la mémoire de travail.Afin de mieux comprendre le type de représentation qu’un enfant élabore au cours de son développement, une deuxième partie de la thèse présente trois expériences étudiant le développement des connaissances sur les repères et la route. Les deux premières études ont permis d’observer une augmentation qualitative et quantitative de la connaissance des repères, c’est-à-dire des entités spécifiques qui jalonnent un itinéraire, mais également de la connaissance de la succession de ces repères et des directions empruntées. Le rôle particulier des repères situés à un changement de direction est attesté chez l’adulte comme chez l’enfant. L’augmentation de ces connaissances avec l’âge est observée avec des tâches de production et de reconnaissance, aussi bien verbales que non-verbales. Ces résultats suggèrent l’existence d’une seule représentation commune ou de deux formats de représentations fortement reliés. Le lien important entre les informations verbales et non-verbales dans les représentations est attesté par l’observation d’un biais de type sémantique dans la reconnaissance visuelle de repères. Cependant, l’analyse des différences interindividuelles a mis en évidence le rôle de capacités visuo-spatiales telles que la perception des directions, mais pas d’influence des capacités langagières sur la capacité de représentation d’itinéraire. Une troisième étude explore le rôle des composantes verbales et visuo-spatiales de la mémoire de travail dans le développement des représentations spatiales au moyen d’un paradigme de double tâche (verbale ou spatiale) lors de la mémorisation d’itinéraires. L’implication, notamment de la composante spatiale de la mémoire de travail au cours de la mémorisation d’itinéraire, est mise en évidence chez l’enfant. Ce résultat renforce l’idée de la dominance d’une forme de codage visuo-spatial dans le développement de la représentation qui évoluerait au profit de codages plus verbaux ou mixtes.En conclusion, cette thèse montre le développement de la capacité à se représenter un itinéraire au cours de l’enfance, attesté par des tâches de nature et de format variés. Si cette représentation semble impliquer à la fois des composantes verbales et non-verbales, ces dernières semblent être plus importantes chez l’enfant. La dernière partie de la thèse propose une discussion des implications de ces résultats pour le développement de la cognition spatiale chez l’enfant, ainsi que des perspectives pour les recherches futures.

International audience; Cancer involves stressful events. One aspect of cognition that is impacted by stress is episodic autobiographical memory (EAM). EAM is intimately linked to self-representation. Some studies have revealed impairment of EAM in patients with breast cancer in remission. Yet, these studies failed to differentiate between the influence of adjuvant treatments and that of psychosocial factors. We therefore assessed the psychological impact of breast cancer diagnosis on EAM and self-representation profiles prior to any adjuvant treatment. Patients newly diagnosed with breast cancer (n=31) and women without any history of cancer (n=49) were compared on state anxiety, EAM and its emotional characteristics, and self-representations. The most anxious patients retrieved fewer emotional details for memories than the controls, and had lower self-representation scores than the least anxious patients, who had no deficits in emotional detail retrieval. Our results revealed distinct EAM profiles for patients, reflecting two contrasting modes of coping with breast cancer.

International audience

International audience

Although many studies have investigated spatial representation in young adults, little is still known about the processes underlying how they construct spatial models, the nature of these models, and how they develop in children. The originality of this thesis is two-fold: it studies both cognitive and linguistic processes involved in how children (5 to 11 years) and adults construct representation of virtual routes; it also examines individual differences in these processes. The first part of this thesis begins with a chapter that presents the main concepts underlying spatial cognition, as well as some experimental evidence concerning adults' spatial knowledge and the development of this knowledge during childhood. A second chapter then focuses on the role of language and a third one on the role of working memory in the construction of spatial representations. In order to understand how children construct spatial representation during development, a second part of the thesis presents three experiments investigating the development of landmark and route knowledge. The first two studies show developments in the quality and quantity of knowledge concerning both landmarks (i.e. specific entities encountered along the route) and the route (i.e. the sequential order of actions and landmarks). They also provide evidence supporting the specific role of landmarks associated with changes of direction ("decisional" landmarks) in children and adults. Developmental changes in spatial knowledge were assessed by both verbal and non-verbal measures, suggesting the existence of a unique representation or of two representations that are strongly related. The relation between verbal and non-verbal information in participants' representations is evidenced by their bias toward choosing a related landmark of the same semantic category, regardless of its visual characteristics. Nevertheless, analyses show that visuo-spatial abilities such as the perception of directions, but not verbal abilities, play a main role in accounting for individual differences. The third study, investigates verbal and visuo-spatial components of working memory, using a dual task paradigm in which participants performed a verbal or spatial interference task while memorizing routes. The results support the idea that representing itineraries mostly involves a spatial mode of encoding in children and a more verbal or mixed encoding in adults. To conclude, this thesis shows a development in children's capacity to build spatial representations of virtual routes. Although their representation seems to integrate both verbal and non-verbal components, non-verbal abilities appear to be most essential for children. The last part of the thesis discusses the implications of our results for our understanding of the development of spatial cognition in children, as well as future perspectives and conclusions., Si de nombreux travaux ont été consacrés aux représentations spatiales chez le jeune adulte, la nature des modèles spatiaux, les processus qui président à leur construction et la façon dont ils se développent sont encore loin d'être compris. L'originalité de cette thèse tient au fait d'étudier conjointement les composantes cognitives et langagières dans l'acquisition des représentations d'itinéraires virtuels par des enfants (de 5 à 11 ans) et des adultes, ainsi que les différences individuelles liées à des capacités générales variées. Dans une première partie, la thèse présente les principaux concepts de la cognition spatiale issus des travaux menés chez l'adulte ainsi que l'état des connaissances théoriques et empiriques actuelles sur le développement des représentations spatiales chez l'enfant. Un chapitre s'intéresse ensuite au rôle du langage dans la construction des représentations spatiales et un autre à celui de la mémoire de travail. Afin de mieux comprendre le type de représentation qu'un enfant élabore au cours de son développement, une deuxième partie de la thèse présente trois expériences étudiant le développement des connaissances sur les repères et la route. Les deux premières études ont permis d'observer une augmentation qualitative et quantitative de la connaissance des repères, c'est-à-dire des entités spécifiques qui jalonnent un itinéraire, mais également de la connaissance de la succession de ces repères et des directions empruntées. Le rôle particulier des repères situés à un changement de direction est attesté chez l'adulte comme chez l'enfant. L'augmentation de ces connaissances avec l'âge est observée avec des tâches de production et de reconnaissance, aussi bien verbales que non-verbales. Ces résultats suggèrent l'existence d'une seule représentation commune ou de deux formats de représentations fortement reliés. Le lien important entre les informations verbales et non-verbales dans les représentations est attesté par l'observation d'un biais de type sémantique dans la reconnaissance visuelle de repères. Cependant, l'analyse des différences interindividuelles a mis en évidence le rôle de capacités visuo-spatiales telles que la perception des directions, mais pas d'influence des capacités langagières sur la capacité de représentation d'itinéraire. Une troisième étude explore le rôle des composantes verbales et visuo-spatiales de la mémoire de travail dans le développement des représentations spatiales au moyen d'un paradigme de double tâche lors de la mémorisation d'itinéraires. L'implication, notamment de la composante spatiale de la mémoire de travail au cours de la mémorisation d'itinéraire, est mise en évidence chez l'enfant. Ce résultat renforce l'idée de la dominance d'une forme de codage visuo-spatial dans le développement de la représentation qui évoluerait au profit de codages plus verbaux ou mixtes. En conclusion, cette thèse montre le développement de la capacité à se représenter un itinéraire au cours de l'enfance, attesté par des tâches de nature et de format variés. Si cette représentation semble impliquer à la fois des composantes verbales et non-verbales, ces dernières semblent être plus importantes chez l'enfant. La dernière partie de la thèse propose une discussion des implications de ces résultats pour le développement de la cognition spatiale chez l'enfant, ainsi que des perspectives pour les recherches futures.

International audience

Focal cortical dysplasia type 2 (FCD2) is a common cause of intractable partial epilepsy surgically treatable. Their detection by MRI is an independent factor of good prognosis. The MR imaging diagnosis remains difficult with up to 40% negative MRI. Our main objective is to improve the detection of FCD2from conventional sequences, to assess the relevance of increased magnetic field and validate new tools for detection, in particular by identifying sulcal abnormalities associated with FCD2 automatically and visually. This study was carried out from one of the largest cohort of patients (> 80 patients) with histologically proven FCD2. The evaluation of the frequency of each MR signs showed that, although no abnormality is seen in 41% of cases, the different signs in patients with a positive MRI were never isolated and the combination of the 3 most suggestive signs of FCD2 (cortical thickening, bluring of the gray-white matter interface and "transmantle sign") was found in 27 patients (64%), indicating that MRI can be very suggestive. By increasing the magnetic field from 1.5 to 3T MRI detection rate is only slightly changed but characterization of FCD2 is improved thanks to a better visualization of the " transmantle sign " considered as a MR signature of FCD2. The automated sulcus analysis based on the calculation of a new parameter called "sulcal energy" identifies abnormal sulcal patterns in patients with FCD2 in the central region in comparison to healthy subjects. This result underlines the importance of the identification of sulci and could provide an additional criterion for detecting and locating the lesion in patients with negative MRI. Finally, the visual analysis of sulci by 3D reformatting of the cortex allowed us to describe a new MR sign of FCD2 in the central region: a sulcal pattern called the "Power Button Sign". Given its excellent reproducibility and specificity, it could be used as a new major diagnostic criterion of FCD2 in the central region. All these results contribute to the better understanding of the developmental processes involved in the pathophysiology of FCD2 and offers many opportunities for improving their MR detection.; Les dysplasies corticales focales de type 2 (DCF2) sont une cause fréquente d’épilepsie partielle pharmacorésistante pouvant bénéficier d’un traitement chirurgical. Leur détection en IRM est un facteur indépendant de bon pronostic. Leur diagnostic reste difficile avec jusqu’à 40% d’IRM négatives. Le travail de cette thèse a pour principal objectif d’améliorer la détection des DCF2 à partir des séquences conventionnelles, d’évaluer la pertinence d’une augmentation de champ magnétique, et de valider de nouveaux outils de détection, en particulier par l’identification d’anomalies des sillons associées aux DCF2 de manière automatique puis visuelles. Cette étude a été réalisée à partir d’une des plus importante cohorte de patients (>80 patients) porteurs de DCF2 prouvée histologiquement. L’évaluation de la fréquence de chacun des signes en IRM nous a permis de démontrer que, bien qu’aucune anomalie ne soit visible dans 41% des cas, les différents signes chez les patients avec une IRM positive n’étaient jamais isolés et que la combinaison des 3 signes les plus évocateurs de DCF2 (épaississement cortical, flou de l'interface blanc-gris et « transmantle sign »), était retrouvée chez 27 patients (64%) suggérant que l’IRM puisse être un examen très caractéristique. En augmentant le champ magnétique de 1,5 à 3T en IRM le taux de détection n’est que peu modifié mais la caractérisation des DCF2 est améliorée en raison d’une meilleure visualisation du « transmantle sign », considéré comme une signature en IRM des DCF2. L’analyse automatisée des sillons basés sur le calcul d’un nouveau paramètre appelé « énergie sulcale » permet d’identifier des motifs sulcaux anormaux chez les patients porteurs de DCF2 dans la région centrale en comparaison aux sujets sains. Ce résultat souligne l'importance d’une étude des sillons et pourrait fournir un critère supplémentaire pour détecter et localiser la lésion chez des patients à IRM négative. Enfin, l’analyse visuelle des sillons par un reformatage 3D du cortex nous a permis de décrire un nouveau marqueur des DCF2 de la région centrale : un motif sulcal dénommé le "Power Button Sign". Compte tenu de son excellente reproductibilité et de sa spécificité, il pourrait être utilisé comme un nouveau critère diagnostic majeur de DCF2 de la région centrale. L’ensemble de ces résultat participe à la meilleure compréhension des phénomènes développementaux impliqués dans la physiopathologie des DCF2 et offre de nombreuses perspectives pour l’amélioration de leur détection en imagerie.

Focal cortical dysplasia type 2 (FCD2) is a common cause of intractable partial epilepsy surgically treatable. Their detection by MRI is an independent factor of good prognosis. The MR imaging diagnosis remains difficult with up to 40% negative MRI. Our main objective is to improve the detection of FCD2from conventional sequences, to assess the relevance of increased magnetic field and validate new tools for detection, in particular by identifying sulcal abnormalities associated with FCD2 automatically and visually. This study was carried out from one of the largest cohort of patients (> 80 patients) with histologically proven FCD2. The evaluation of the frequency of each MR signs showed that, although no abnormality is seen in 41% of cases, the different signs in patients with a positive MRI were never isolated and the combination of the 3 most suggestive signs of FCD2 (cortical thickening, bluring of the gray-white matter interface and "transmantle sign") was found in 27 patients (64%), indicating that MRI can be very suggestive. By increasing the magnetic field from 1.5 to 3T MRI detection rate is only slightly changed but characterization of FCD2 is improved thanks to a better visualization of the " transmantle sign " considered as a MR signature of FCD2. The automated sulcus analysis based on the calculation of a new parameter called "sulcal energy" identifies abnormal sulcal patterns in patients with FCD2 in the central region in comparison to healthy subjects. This result underlines the importance of the identification of sulci and could provide an additional criterion for detecting and locating the lesion in patients with negative MRI. Finally, the visual analysis of sulci by 3D reformatting of the cortex allowed us to describe a new MR sign of FCD2 in the central region: a sulcal pattern called the "Power Button Sign". Given its excellent reproducibility and specificity, it could be used as a new major diagnostic criterion of FCD2 in the central region. All these results contribute to the better understanding of the developmental processes involved in the pathophysiology of FCD2 and offers many opportunities for improving their MR detection.; Les dysplasies corticales focales de type 2 (DCF2) sont une cause fréquente d’épilepsie partielle pharmacorésistante pouvant bénéficier d’un traitement chirurgical. Leur détection en IRM est un facteur indépendant de bon pronostic. Leur diagnostic reste difficile avec jusqu’à 40% d’IRM négatives. Le travail de cette thèse a pour principal objectif d’améliorer la détection des DCF2 à partir des séquences conventionnelles, d’évaluer la pertinence d’une augmentation de champ magnétique, et de valider de nouveaux outils de détection, en particulier par l’identification d’anomalies des sillons associées aux DCF2 de manière automatique puis visuelles. Cette étude a été réalisée à partir d’une des plus importante cohorte de patients (>80 patients) porteurs de DCF2 prouvée histologiquement. L’évaluation de la fréquence de chacun des signes en IRM nous a permis de démontrer que, bien qu’aucune anomalie ne soit visible dans 41% des cas, les différents signes chez les patients avec une IRM positive n’étaient jamais isolés et que la combinaison des 3 signes les plus évocateurs de DCF2 (épaississement cortical, flou de l'interface blanc-gris et « transmantle sign »), était retrouvée chez 27 patients (64%) suggérant que l’IRM puisse être un examen très caractéristique. En augmentant le champ magnétique de 1,5 à 3T en IRM le taux de détection n’est que peu modifié mais la caractérisation des DCF2 est améliorée en raison d’une meilleure visualisation du « transmantle sign », considéré comme une signature en IRM des DCF2. L’analyse automatisée des sillons basés sur le calcul d’un nouveau paramètre appelé « énergie sulcale » permet d’identifier des motifs sulcaux anormaux chez les patients porteurs de DCF2 dans la région centrale en comparaison aux sujets sains. Ce résultat souligne l'importance d’une étude des sillons et pourrait fournir un critère supplémentaire pour détecter et localiser la lésion chez des patients à IRM négative. Enfin, l’analyse visuelle des sillons par un reformatage 3D du cortex nous a permis de décrire un nouveau marqueur des DCF2 de la région centrale : un motif sulcal dénommé le "Power Button Sign". Compte tenu de son excellente reproductibilité et de sa spécificité, il pourrait être utilisé comme un nouveau critère diagnostic majeur de DCF2 de la région centrale. L’ensemble de ces résultat participe à la meilleure compréhension des phénomènes développementaux impliqués dans la physiopathologie des DCF2 et offre de nombreuses perspectives pour l’amélioration de leur détection en imagerie.

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International audience; Information that is processed with reference to oneself, i.e. Self-Referential Processing (SRP), is generally associated with better remembering compared to information processed in a condition not related to oneself. This positive effect of the self on subsequent memory performance is called as Self-Reference Effect (SRE). The neural basis of SRE is still poorly understood. The main goal of the present work was thus to highlight brain changes associated with SRE in terms of activity and functional coupling and during both encoding and retrieval so as to assess the relative contribution of both processes to SRE. For this purpose, we used an fMRI event-related self-referential paradigm in 30 healthy young subjects and measured brain activity during both encoding and retrieval of self-relevant information compared to a semantic control condition. We found that SRE was associated with brain changes during the encoding phase only, including both greater activity in the medial prefrontal cortex and hippocampus, and greater functional coupling between these brain regions and the posterior cingulate cortex. These findings highlight the contribution of brain regions involved in both SRP and episodic memory and the relevance of the communication between these regions during the encoding process as the neural substrates of SRE. This is consistent with the idea that SRE reflects a positive effect of the reactivation of self-related memories on the encoding of new information in episodic memory.

International audience; Semantic dementia (SD) is characterized by gradual loss of semantic memory. While episodic autobiographical memory seems relatively preserved, behavioral studies suggest that episodic future thinking is impaired. We used fMRI to measure brain activity in four SD patients (JPL, EP, LL, EG) while they envisioned future events and remembered personal past events. Twelve healthy elders served as controls. Episodic quality, emotion, mental imagery and level of consciousness (via remember/know judgements) were checked at debriefing. We analyzed the future compared to the past for each patient. All patients presented lateral temporal atrophy, but varied in terms of frontal and anterior hippocampal atrophy. Patient JPL presented atrophy in bilateral superior medial frontal gyri and left anterior hippocampus and was unable to engage in episodic future thinking, despite hyperactivations in frontal and occipital regions. Patient EP presented no atrophy in the anterior hippocampus, but atrophy in bilateral superior medial frontal gyrus and had difficulties to engage in episodic future thinking. Patient LL presented atrophy in left anterior hippocampus, but hyperactivated its right counterpart for future compared to past thinking, permitting her to project efficiently in the future in an episodic way. Patient EG presented no atrophy in the superior medial frontal gyri or anterior hippocampi and was able to engage in episodic future thinking. Altogether, patients' future projections differed depending on the severity and localization of their atrophy. The functional integrity of bilateral superior medial frontal gyri and anterior hippocampus appear crucial for episodic future thinking: atrophy of both structures strongly impairs future projection, while integrity of these structures or hyperactivation of residual tissue normalizes episodic future projection.

International audience; Use of morphologically related words often helps in selecting among spellings of sounds in French. For instance, final /wa/ may be spelled oi (e.g., envoi “sendoff”), oit (e.g., exploit “exploit”), ois (e.g., siamois, “siamese”), or oie (e.g., joie “joy”). The morphologically complex word exploiter “to exploit”, with a pronounced t, can be used to indicate that the stem exploit is spelled with a silent t. We asked whether 8-year-old children benefited from such cues to learn new spellings. Children read silently stories which included two target nonwords, one presented in an opaque condition and the other in a morphological condition. In the opaque condition, the sentence provided semantic information (e.g., a vensois is a musical instrument) but no morphological information that could justify the spelling of the target word's final sound. Such justification was available in the morphological condition (e.g., the vensoisist plays the vensois instrument, which justifies that vensois includes a final silent s). 30 min after having read the stories, children's orthographic learning was assessed by asking them to choose the correct spelling of each nonword from among three phonologically plausible alternatives (e.g., vensois, vensoit, vensoie). Children chose correct spellings more often in the morphological condition than the opaque condition, even though the root (vensois) had been presented equally often in both conditions. That is, children benefited from information about the spelling of the morphologically complex word to learn the spelling of the stem.

International audience; Autobiographical memory is commonly impaired in Alzheimer's disease (AD). However, little is known about the very recent past which is though highly important in daily life adaptation. In addition, the impact of sleep disturbances, also frequently reported in AD, on the consolidation and retrieval of autobiographical memories remains to be assessed. Using an adaptation of the TEMPau task, we investigated the neural substrates of autobiographical memory for recent events and the potential relationship with sleep in 14 patients with mild AD. On day 1, autobiographical memory was explored across 3 periods: remote (18-30 years), the last two years and the last month. After testing, sleep was recorded using polysomnography. The next day, AD patients benefited a resting state 18FDG-PET scan and a second exploration of autobiographical memory, focusing on the very recent past (today and yesterday). Total recall and episodic recall scores were obtained. In addition, for all events recalled, Remember responses justified by specific factual, spatial and temporal details were measured using the Remember/Know paradigm. Retrieval of autobiographical memories was impaired in AD, but recall of young adulthood and very recent events was relatively better compared to the two intermediate periods. Recall of recent events (experienced the day and the day preceding the assessment) was correlated with brain glucose consumption in the precuneus and retrosplenial cortex, the calcarine region, the angular gyrus and lateral temporal areas. AD patients also provided more Justified Remember responses for events experienced the previous day than for those experienced the day of the assessment. Moreover, Justified Remember responses obtained for events experienced before sleep were positively correlated with the amount of slow-wave sleep. These data provide the first evidence of an association between the ability to retrieve recent autobiographical memories and sleep in mild AD patients.

International audience; Autobiographical memory is commonly impaired in Alzheimer's disease (AD). However, little is known about the very recent past which is though highly important in daily life adaptation. In addition, the impact of sleep disturbances, also frequently reported in AD, on the consolidation and retrieval of autobiographical memories remains to be assessed. Using an adaptation of the TEMPau task, we investigated the neural substrates of autobiographical memory for recent events and the potential relationship with sleep in 14 patients with mild AD. On day 1, autobiographical memory was explored across 3 periods: remote (18-30 years), the last two years and the last month. After testing, sleep was recorded using polysomnography. The next day, AD patients benefited a resting state 18FDG-PET scan and a second exploration of autobiographical memory, focusing on the very recent past (today and yesterday). Total recall and episodic recall scores were obtained. In addition, for all events recalled, Remember responses justified by specific factual, spatial and temporal details were measured using the Remember/Know paradigm. Retrieval of autobiographical memories was impaired in AD, but recall of young adulthood and very recent events was relatively better compared to the two intermediate periods. Recall of recent events (experienced the day and the day preceding the assessment) was correlated with brain glucose consumption in the precuneus and retrosplenial cortex, the calcarine region, the angular gyrus and lateral temporal areas. AD patients also provided more Justified Remember responses for events experienced the previous day than for those experienced the day of the assessment. Moreover, Justified Remember responses obtained for events experienced before sleep were positively correlated with the amount of slow-wave sleep. These data provide the first evidence of an association between the ability to retrieve recent autobiographical memories and sleep in mild AD patients.

International audience; The vestibular system constitutes an inertial sensor, which detects linear (otoliths) and angular (semicircular canals) accelerations of the head in the three dimensions. The otoliths are specialized in the detection of linear accelerations and can be used by the brain as a "plumb line" coding earth gravity acceleration (direction). This property of otolithic system suggested that the sense of verticality is supported by the vestibular system. The preeminence of vestibular involvement in the sense of verticality stated in the 1900s was progressively supplanted by the notion of internal models of verticality. The internal models of verticality involve rules and properties of integration of vestibular graviception, somaesthesic graviception, and vision. The construction of a mental representation of verticality was mainly modeled as a bottom-up organization integrating visual, somatosensory and vestibular information without any cognitive modulations. Recent studies reported that the construction of internal models of verticality is not an automatic multi-sensory integration process but corresponds to more complex mechanisms including top-down influences such as awareness of body orientation or spatial representations.

EnglishPicture naming is a highly popular task in language production research. In particular, the frequency effect obtained in picture naming is generally considered as the signature of lexical access in speech production. However, it is quite well established that picture naming is very sensitive to the phonetic properties of the word to be produced, imposing some limitations in using this task. In this paper, we look for a frequency effect in the lexical access to picture names, by means of a phoneme-monitoring task. This task requires access to the object name’s phonological representation but not its actual articulation. We found a robust frequency effect. Two additional experiments—visual object identification and semantic categorization—allow us to assume that the locus for the frequency effect is lexical. francaisLa denomination d’images est une procedure privilegiee pour l’etude de la production du langage. En particulier, l’effet de frequence en denomination a ete considere comme la signature de l’acces au lexique mental. Toutefois, en raison de sa nature articulatoire, la reponse de denomination est tres sensible aux proprietes phonetiques du mot a produire, ce qui contraint son utilisation. Dans cet article, nous examinons l’effet de frequence dans l’acces lexical aux noms d’image en utilisant une tâche de detection de phoneme. Cette tâche necessite l’acces a la representation phonologique du nom de l’objet, mais pas son articulation. Nous trouvons un effet robuste de frequence. Deux experiences complementaires –identification d’objet visuel et categorisation semantique – nous permettent de supposer que le locus de l’effet de frequence est lexical.

Two experiments investigate how people create spatial mental models (SMMs) as a function of presentation format. Spatial representations following a route within a virtual environment (visual) and an auditory description (verbal) were compared. Moreover, a dual-task procedure was adopted to depict the role of working memory (WM) components in such a task. Two testing formats were examined in both experiments: sentence verification (verbal) and sketch map (visual) tasks. This studyshows that both presentations lead to adequate spatial representation. Nonetheless, SMMs are not presentation free. They are built by virtual presentation with a contribution of visuo-spatial WM. An involvement of verbal WM emerged while encoding spatial information from both verbal and virtual presentation. Congruency between presentation and testing formats slightly reduces the gap between verbal and virtual presentation. SMMs appear to be affected by the interaction of presentation and testing format as well as by the WM availability. Copyright © 2013 John Wiley & Sons, Ltd.

International audience; IntroductionIn the field of education, results have shown that text personalization allows for a processing of textual information. Several researchers have explained this advantage using the concept of “schema” but have not taken into account the linguistic nature of the texts.ObjectiveIn this study, we tested the importance of texts in the personalization effect. To do so, four groups of participants were contrasted with regard to the type of material (lists vs. texts) and personalization (personalized vs. non-personalized).MethodPersonalization consisted of introducing, or not, biographical elements allowing the reader to have, or not, a very familiar material to read. Therefore, two personalized groups that read some verbal material (lists or texts) mentioning some familiar locations were compared to two non-personalized groups that read verbal material (lists or texts) featuring unfamiliar locations. For the four groups, each location was associated with two objects. After the presentation phase, participants had to recognize the objects.ResultsAs expected, the personalized group recognized the objects more rapidly than the other group. A second finding showed that when the locations were not inserted in the texts (i.e., in lists), the personalization effect disappeared.ConclusionResults suggest that an explanation just in terms of “schemas” is insufficient. We think that the long-term working memory theory (Ericsson & Kintsch, 1995) allows us to complete this explanation thanks to the concept of episodic text memory.; Dans le domaine de l’éducation, des résultats ont montré que la personnalisation d’un texte permettait d’obtenir un traitement plus efficace du texte. Plusieurs chercheurs ont expliqué cet avantage en mettant en avant le concept de schéma, sans que la nature linguistique des textes n’entre en ligne de compte. Nous avons voulu au travers d’une expérience tester l’importance des textes dans l’effet de personnalisation. Pour cela, quatre groupes de participants ont été contrastés quant au matériel test (listes vs. textes) et la personnalisation (personnalisé vs. non personnalisé). La personnalisation permettait d’introduire, ou pas, des éléments biographiques dans le matériel test, ce qui permettait au lecteur d’avoir un matériel familier à traiter, ou pas. Ainsi deux groupes dits « personnalisés » lisant un matériel linguistique (listes ou textes) qui comportait des lieux familiers étaient comparés à deux groupes dits « non personnalisés » lisant un matériel linguistique (listes ou textes) comportant des lieux non familiers. Pour les quatre groupes, chaque lieu était associé à deux objets. Après la phase de présentation, les participants devaient reconnaître les bonnes associations objets-lieu. Comme attendu, le groupe personnalisé a reconnu les objets plus rapidement que le groupe non personnalisé. Les données montrent également que lorsque les lieux ne sont pas inclus dans des textes, l’effet de personnalisation disparaît. Cela semble suggérer qu’une interprétation en termes de schéma est incomplète. Nous pensons que la théorie de la mémoire de travail à long terme (Ericsson & Kintsch, 1995) permet de compléter cette explication notamment au travers de la notion de mémoire épisodique de texte.

The present study investigates the joint role of spatial ability, imagery strategy and visuospatial working memory (VSWM) in spatial text processing. A set of 180 participants, half of them trained on the use of imagery strategy (training vs no-training groups), was further divided according to participants' high or low mental rotation ability (HMR vs LMR). Each group listened to environment descriptions and performed recall tasks before and immediately after training/no-training, and again after listening to a text while performing a spatial tapping task. Visuospatial and verbal tests were also administered. Our results showed that HMR had a better spatial profile than LMR participants, and that only LMR participants benefited fromtraining and showed the interference effect. Overall, our findings indicate that a good spatial ability reduces the spatial interference effect and that poor spatial ability,which is related to the spatial interference effect, can be partially compensated by learning imagery strategy.

The aim of this study is to broaden our understanding of the construction and early decline of spatial mental representations in route learning, considering the extent to which spatial ability and age-related differences in environment learning interact. The experiment examines spatial mental representation derived from taking a realistic route acquired using virtual environment and compares individuals different in age but with similar spatial ability. A sample of 34 young (20–30 years) and 30 middle-aged (50–60 years) females with good mental rotation ability were chosen. Participants learned a complex route through its presentation in a virtual environment and then performed a series of tasks (landmark recognition, location of landmarks and verification of spatial relations). Results show that the two participant age groups had similar performance in landmark recognition task and in verification of sentences describing direct spatial relations; instead, the middle-aged group showed a poorer performance than younger in their ability to locate landmarks and to judge the truth of indirect spatial sentences. These results first suggest that spatial abilities have to be seriously considered to avoid any confusion with age, as age-related differences are attenuated when individuals are different in age but similar in spatial ability. Second they confirm a specific difficulty of older participants to handle spatial information in a global configuration.

The origins of poor insight in schizophrenia are still unclear. We contrasted the changes in clinical insight, basic cognitive processes, autobiographical memory and metacognition in 63 outpatient’s with schizophrenia pseudo-randomly assigned to one of three cognitive remediation groups: one targeting basic cognitive processes (RECOS), a second autobiographical memory (REMAu), and a third metacognitive deficits (MBCT). Three dimensions of insight (awareness of: mental illness, benefit of treatment, psychosocial consequences) improved after treatment, regardless of the group. In addition, the REMAu and MBCT showed an improvement on other dimensions of insight (symptomatic awareness and symptomatic attribution, respectively). Poor insight and its improvement after treatment were best predicted by a combination of basic cognitive, autobiographical and metacognitive measures. This study supports a multidimensional conception of insight and recommends the combination of remediation therapies to improve clinical insight in schizophrenia.; Dans la schizophrénie, le déficit d’insight est d’une importance clinique majeure de fait de son lien étroit avec l’observance médicamenteuse et l’alliance thérapeutique. Ce travail propose au moyen de trois études l’exploration du concept d’insight, précisant les mécanismes cognitifs sous-tendus et évaluant les effets de 3 nouvelles prises en charge sur son niveau d’évolution. Nous nous sommes basés pour cela sur trois modèles théoriques, celui de Conway (2005) qui établit des liens étroits entre le self et la mémoire autobiographique, celui de Larøi et al., (2004) suggérant à l’origine du déficit d’insight un trouble de la conscience autonoétique en lien avec la mémoire autobiographique, et enfin, celui de Agnew et Morris (1989) incriminant une palette de troubles cognitifs et métacognitifs dans le déficit d’insight. Nos résultats soulignent le rôle primordial de la mémoire autobiographique dans le déficit d’insight et notamment la qualité des souvenirs sur la période supérieur à >20 ans. De plus les résultats indiquent que, les modèles autobiographique et métacognitif prédisent mieux le déficit d’insight comparés au modèle cognitif de base. Parmi les trois programmes thérapeutiques, le programme RECOS (Vianin, 2007), améliore de manière significative le fonctionnement cognitif. Le programme REMAu (Piolino, 2006), visant la reconstruction des souvenirs autobiographique en lien avec le self, améliore de façon significative la conscience du trouble mental et la qualité du rappel épisodique. Le programme MBCT (Segal, Williams et Teasdale, 2002), visant la prise de conscience du moment présent, améliore de façon significative la capacité à attribuer la symptomatologie à la maladie mentale, l’estime de soi et la théorie de l’esprit. Ces résultats nous amènent à proposer un modèle explicatif et multidimensionnel du déficit d’insight dans la schizophrénie, intégrant les trois modèles étudiés ; cognitif, métacognitif et autobiographique.

The origins of poor insight in schizophrenia are still unclear. We contrasted the changes in clinical insight, basic cognitive processes, autobiographical memory and metacognition in 63 outpatient’s with schizophrenia pseudo-randomly assigned to one of three cognitive remediation groups: one targeting basic cognitive processes (RECOS), a second autobiographical memory (REMAu), and a third metacognitive deficits (MBCT). Three dimensions of insight (awareness of: mental illness, benefit of treatment, psychosocial consequences) improved after treatment, regardless of the group. In addition, the REMAu and MBCT showed an improvement on other dimensions of insight (symptomatic awareness and symptomatic attribution, respectively). Poor insight and its improvement after treatment were best predicted by a combination of basic cognitive, autobiographical and metacognitive measures. This study supports a multidimensional conception of insight and recommends the combination of remediation therapies to improve clinical insight in schizophrenia.; Dans la schizophrénie, le déficit d’insight est d’une importance clinique majeure de fait de son lien étroit avec l’observance médicamenteuse et l’alliance thérapeutique. Ce travail propose au moyen de trois études l’exploration du concept d’insight, précisant les mécanismes cognitifs sous-tendus et évaluant les effets de 3 nouvelles prises en charge sur son niveau d’évolution. Nous nous sommes basés pour cela sur trois modèles théoriques, celui de Conway (2005) qui établit des liens étroits entre le self et la mémoire autobiographique, celui de Larøi et al., (2004) suggérant à l’origine du déficit d’insight un trouble de la conscience autonoétique en lien avec la mémoire autobiographique, et enfin, celui de Agnew et Morris (1989) incriminant une palette de troubles cognitifs et métacognitifs dans le déficit d’insight. Nos résultats soulignent le rôle primordial de la mémoire autobiographique dans le déficit d’insight et notamment la qualité des souvenirs sur la période supérieur à >20 ans. De plus les résultats indiquent que, les modèles autobiographique et métacognitif prédisent mieux le déficit d’insight comparés au modèle cognitif de base. Parmi les trois programmes thérapeutiques, le programme RECOS (Vianin, 2007), améliore de manière significative le fonctionnement cognitif. Le programme REMAu (Piolino, 2006), visant la reconstruction des souvenirs autobiographique en lien avec le self, améliore de façon significative la conscience du trouble mental et la qualité du rappel épisodique. Le programme MBCT (Segal, Williams et Teasdale, 2002), visant la prise de conscience du moment présent, améliore de façon significative la capacité à attribuer la symptomatologie à la maladie mentale, l’estime de soi et la théorie de l’esprit. Ces résultats nous amènent à proposer un modèle explicatif et multidimensionnel du déficit d’insight dans la schizophrénie, intégrant les trois modèles étudiés ; cognitif, métacognitif et autobiographique.

International audience; A total of 136 with or without first-degree relatives with alcohol dependence were compared according to lifetime prevalence of psychiatric disorders and personality dimensions. Family history positive women showed significant higher prevalence rates of depression and agoraphobia, and exhibited lower scores on Reward Dependence, Self-Directedness and Cooperativeness dimensions.

article i nfo The aim of this research was to examine age-related differences in young and older adults in route learning, using different types of learning and recall test modalities. A sample of young adults (20-30 years old) and older adults (60-70 years old) learned a city route by using either a map or a description; they then per- formed a verification (verbal task) and map drawing (visuo-spatial task) tests. Results showed that, in both age groups, the effect of the learning condition changed as a function of the recall task: only after map learning did participants perform better in map drawing than in sentence verification tasks (no differ- ences between the two measures were found in the description condition). The type of learning modality also showed age differences, but was detected only in the map drawing task: after map learning (but not after description learning) older adults did perform like younger adults in map drawing. However, age- related differences were mainly found in relation to type of recall task. In the verification test, older adults performed like younger ones in direct spatial sentences, but older adults underperformed in indirect sen- tences (in which test information was not explicitly presented). In map drawing, the two groups performed similarly in remembering and ordering landmarks, whereas older adults underperformed in positioning the landmarks correctly. These results suggest that recall tests are sensitive modalities in examining age-related differences, revealing which abilities are preserved (or otherwise) in mental route representations.

International audience; The increasing use of mobile phones by children raise issues about the effects of electromagnetic fields (EMF) on the immature Central Nervous System (CNS). In the present study, we quantified cell stress and glial responses in the brain of developing rats one day after a single exposure of 2 h to a GSM 1,800 MHz signal at a brain average Specific Absorption Rate (SAR) in the range of 1.7 to 2.5 W/kg. Young rats, exposed to EMF on postnatal days (P) 5 (n = 6), 15 (n = 5) or 35 (n = 6), were compared to pseudo-exposed littermate rats (n = 6 at all ages). We used western blotting to detect heat shock proteins (HSPs) and cytoskeleton- or neurotransmission-related proteins in the developing astroglia. The GSM signal had no significant effect on the abundance of HSP60, HSC70 or HSP90, of serine racemase, glutamate transporters including GLT1 and GLAST, or of glial fibrillary acid protein (GFAP) in either total or soluble tissue extracts. Imunohistochemical detection of CD68 antigen in brain sections from pseudo-exposed and exposed animals did not reveal any differences in the morphology or distribution of microglial cells. These results provide no evidence for acute cell stress or glial reactions indicative of early neural cell damage, in developing brains exposed to 1,800 MHz signals in the range of SAR used in our study.

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This research investigates how visuo-spatial abilities (such as mental rotation — MR — and visuo-spatial working memory — VSWM —) work together to influence the recall of environmental descriptions. We tested a mediation model in which VSWM was assumed to mediate the relationship between MR and spatial text recall. First, 120 participants were assessed for MR and working memory (both visuo-spatial and verbal) abilities. Participants then listened to spatial descriptions and performed spatial recall tasks. The expected model was verified, indicating that it is possible to define an order for how visuo-spatial abilities modulate environmental learning, with MR as a predictor and VSWM as a mediator.