O estabelecimento das memórias de longo prazo requer uma efetiva comunicação do hipocampo com o neocortex. Um mecanismo plausível envolvido na comunicação neuronal e na plasticidade sináptica é a sincronização da atividade elétrica cerebral na frequência teta. Estudos recentes mostraram que a sincronização entre os ritmos teta do hipocampo e do córtex pré-frontal aumenta durante a evocação das memórias aversivas e diminui após a extinção do aprendizado. Entretanto, outros ritmos cerebrais, como as ondas delta, também estão envolvidos nas respostas comportamentais do medo e nos processos de memória. Desta forma, o ritmo teta, que já foi bastante estudado pelo seu papel no aprendizado e na memória, e o ritmo delta, por seu envolvimento no ciclo sono-vigília, foram investigados considerando a relação causal entre eles. Ainda não está bem estabelecido como os ritmos delta e teta podem juntos contribuir nos processos cognitivos ou como os ritmos do hipocampo podem influenciar ou receber influencias da atividade cortical. Neste trabalho foi investigada a contribuição dos ritmos delta e teta em função do estado comportamental (vigília ativa ou congelamento) e do tipo de memória evocada (recente ou remota). Além disso, foi realizada uma análise de sincronia de fase para inferir a dinâmica da atividade elétrica entre o córtex pré-frontal medial, o hipocampo e o córtex visual durante a evocação das memórias de medo. Para tanto, os animais foram treinados e testados numa tarefa de condicionamento de medo ao contexto. Neste tipo de condicionamento, o animal aprende a estabelecer uma associação entre um determinado contexto (caixa de condicionamento) e um evento aversivo (choque elétrico nas patas) que ocorreu neste contexto. Quando o animal foi reintroduzido na caixa de condicionamento, o mesmo exibiu uma série de respostas condicionadas incluindo a reação de congelamento. Os resultados mostraram que os ritmos delta e teta estão relacionados de forma específica às respostas comportamentais de medo e de evocação das memórias recente e remota. Observou-se no espectro de potências uma maior contribuição do ritmo teta durante a vigília exploratória, diminuindo durante o congelamento. Neste último, os ratos apresentaram um robusto aumento da contribuição do ritmo delta. Além disso, a medida de causalidade mostrou ser dependente do estado comportamental do animal. Finalmente, um aumento da sincronia entre o hipocampo e o córtex pré-frontal foi evidenciado durante a evocação de memória recente, contraposta à diminuição durante a evocação da memória remota. Estes resultados indicam que a sincronização da atividade elétrica cerebral pode refletir uma facilitação na comunicação neuronal / The establishment of long-term memories requires effective communication of the hippocampus to the neocortex. Electrophysiological activities between hippocampus and prefrontal cortex have shown higher theta synchronization during retrieval of aversive memories and lower during extinction learning. While theta activity is more differently related to learning and memory, delta waves have been more discussed in the context of sleep or \"offline\" states. Few studies have investigated delta waves during \"on-line\" states (such as task-relevant situations) and the contribution of these rhythms to memory storage remains unclear. We recorded electrophysiological data to study the contributions of delta and theta waves in cortico-hippocampal system of rats underwent to contextual fear conditioning. Our experiment consisted of environmental pre-exposition, training with electrical footshocks, and recent/remote memory tests. Two groups of rats were tested one or eighteen days post training for recent or remote memory, respectively. Local field potential time series of two behavioral states were sampled: active exploration and freezing. The results showed that theta and delta rhythms play an important role in behavioral responses and memory processing. They are related to fear recall and their contribution depend on the recent or remote memory. Additionally, using an order parameter we show that theta contribution is strongly pronounced in active exploration, decreasing during freezing. In the latter, the rats presented pronounced delta waves in freezing. Moreover, a behavioral-dependent causality measure showed an increase of theta influence in delta rhythms, resulting in a theta slowing in aversive memory retrieval. Finally, we show an increased synchrony between hippocampus and prefrontal cortex during recall of recent memory, but a decreased synchrony in remote memory. We proposed that synchronized activity may facilitate the communication of information and once the memories are established in the neocortex, the synchronization decreases, and recalling them becomes more independent of the hippocampus. We proposed that delta-theta oscillations of the hippocampus over neocortical areas reflect information processing during aversive memory retrieval

The aim of this thesis was to help elucidate the mechanisms that underlie age-related decline in visual selective attention and working memory (WM). Older and younger adults completed a behavioural WM task, after which electroencephalogram (EEG) was recorded as participants perform a localized attentional interference (LAI) task – competition/attentional interference was manipulated by systematically altering the distance between targets and distractors. Older adults showed impaired accuracy and reaction time on the WM and LAI tasks. Two event-related-potentials, indexing spatial attention (N2pc) and target processing (Ptc), displayed attenuated amplitude and increased latency in older adults. Thus, spatial selection, target enhancement and processing speed deficits may contribute to age-related attentional impairments. Furthermore, an unexpected component was found between the N2pc and Ptc in the older adult waveforms. Preliminary analyses suggest this may be the PD, implicated in distractor suppression, which may be differentially contributing to older and younger adults’ electrophysiology and attentional processing.

L’approche psycholinguistique suggère que la rétention à court terme verbale et le langage dépendent de mécanismes communs. Elle prédit que les caractéristiques linguistiques des items verbaux (e.g. phonologiques, lexicales, sémantiques) influencent le rappel immédiat (1) et que la contribution des niveaux de représentations linguistiques dépend du contexte de rappel, certaines conditions expérimentales (e.g. format des stimuli) favorisant l’utilisation de codes spécifiques (2). Ces prédictions sont évaluées par le biais de deux études empiriques réalisées auprès d’une patiente cérébrolésée qui présente une atteinte du traitement phonologique (I.R.) et de participants contrôles. Une première étude (Article 1) teste l’impact des modes de présentation et de rappel sur les effets de similarité phonologique et de catégorie sémantique de listes de mots. Une seconde étude (Article 2) évalue la contribution du code orthographique en mémoire à court terme (MCT) verbale en testant l’effet de la densité du voisinage orthographique des mots sur le rappel sériel immédiat de mots présentés visuellement. Compte tenu du rôle déterminant du code phonologique en MCT et du type d’atteinte de I.R., des effets linguistiques distincts étaient attendus chez elle et chez les contrôles. Selon le contexte de rappel, des effets sémantiques (Article 1) et orthographiques (Article 2) plus importants étaient prédits chez I.R. et des effets phonologiques plus marqués étaient attendus chez les participants contrôles. Chez I.R., le rappel est influencé par les caractéristiques sémantiques et orthographiques des mots, mais peu par leurs caractéristiques phonologiques et le contexte de rappel module l’utilisation de différents niveaux de représentations linguistiques. Chez les contrôles, une contribution relativement plus stable des représentations phonologiques est observée. Les données appuient une approche psycholinguistique qui postule que des mécanismes communs régissent la rétention à court terme verbale et le langage. Les implications théoriques et cliniques des résultats sont discutées en regard de modèles psycholinguistiques actuels. / The psycholinguistic view of verbal short-term retention suggests that verbal short-term retention and language processing rely on common mechanisms. It predicts that all linguistic characteristics of verbal items (e.g. phonological, lexical, semantic) influence their immediate recall (1). It also predicts that the relative contribution of the different linguistic representational levels is a function of the recall context (2). In this view, some experimental conditions (e.g. modes of presentation of stimuli) are thought to promote the use of specific coding. Two studies assess these predictions in a brain-damaged patient (I.R.) who shows a phonological deficit as well as in control participants. In a first article, the impact of presentation and recall modes on phonological and semantic similarity effects of words is tested. In a second article, the contribution of orthographic coding in verbal short-term memory (STM) is assessed by testing the effect of orthographic Neighborhood (N) density of words on immediate serial recall (ISR) of written words. Due to her phonological deficit and because phonological representations play a predominant role in STM, distinct linguistic effects were expected in I.R. and in controls. Overall, (and) depending on the recall context, larger semantic and orthographic effects were predicted in I.R. and larger phonological effects were predicted in controls. In I.R., the data indicate that recall is influenced by semantic and orthographic characteristics of items but less by their phonological properties. The results also indicate that the impact of representations depends of recall conditions. In controls, a different pattern of results is obtained, suggesting an overall predominant contribution of phonological representations. Results support the psycholinguistic view of verbal short-term retention and are discussed in regard to current interactive activation psycholinguistic models of verbal STM and language processing.

The aim of this thesis was to help elucidate the mechanisms that underlie age-related decline in visual selective attention and working memory (WM). Older and younger adults completed a behavioural WM task, after which electroencephalogram (EEG) was recorded as participants perform a localized attentional interference (LAI) task – competition/attentional interference was manipulated by systematically altering the distance between targets and distractors. Older adults showed impaired accuracy and reaction time on the WM and LAI tasks. Two event-related-potentials, indexing spatial attention (N2pc) and target processing (Ptc), displayed attenuated amplitude and increased latency in older adults. Thus, spatial selection, target enhancement and processing speed deficits may contribute to age-related attentional impairments. Furthermore, an unexpected component was found between the N2pc and Ptc in the older adult waveforms. Preliminary analyses suggest this may be the PD, implicated in distractor suppression, which may be differentially contributing to older and younger adults’ electrophysiology and attentional processing.

Summaries in Afrikaans and English / Text in Afrikaans / Two opposing approaches to beginning reading are used, namely the phonological and global approach, under which the whole word, whole sentence and whole language methods are classed. The whole crux of the controversy is situated in beginning reading as an explicit, intensive and systematic method of teaching phonics, as opposed to implicit beginning reading through discrimination of global configurations, augmented by psycholinguistic guesses within reading context. Arguments about the advantages and disadvantages of the opposing methods have been hurdled to and fro for decades without any discernible gain. The question emerged whether research on brain physiology with respect to language and reading, a relatively new field of study, could shed light on the foundation of an accountable method for beginning reading. Renewed insights to the controversial differences were gained, and brain physiologically accountable parameters as a base for a beginning reading method were framed from these insights. / Twee opponerende aanvangsleesbenaderings word in die skole gebruik, naamlik die fonologiese benadering en die geheelbenadering, waaronder die geheelwoord-, geheelsinen die geheeltaalmetode ressorteer. Die kern van die verskil tussen die aanvangsleesbenaderings le in aanvangslees as eksplisiete, intensiewe en sistematiese foneemonderrig, teenoor implisiete aanvangslees wat die waarneming van globale konfigurasies, aangevul deur psigolinguistiese raaiskote binne die leeskonteks, aanmoedig. In die polemiek om die beste leesmetode word argumente oor die voor- en nadele ten opsigte van die begronding van hierdie opponerende metodes reeds dekades heen en weer geslinger. Navorsingsresultate word eindeloos, sonder duidelike winste, met mekaar vergelyk. Dit het die vraag laat onstaan of navorsing ten opsigte van die breinfisiologie met betrekking tot taal en lees, 'n relatief nuwe studieveld, moontlik lig sou kon werp op die begronding van 'n verantwoordbare aanvangsleesmetode. Die literatuurstudie ten opsigte van breinfisiologie het vernuwende insigte oor die polemiese begrondingsverskille na vore gebring, en breinfisiologies-verantwoordbare parameters as basis vir 'n aanvangsleesmetode is uit hierdie insigte opgestel. / Psychology of Education / M. Ed. (Psychology of Education)

O estabelecimento das memórias de longo prazo requer uma efetiva comunicação do hipocampo com o neocortex. Um mecanismo plausível envolvido na comunicação neuronal e na plasticidade sináptica é a sincronização da atividade elétrica cerebral na frequência teta. Estudos recentes mostraram que a sincronização entre os ritmos teta do hipocampo e do córtex pré-frontal aumenta durante a evocação das memórias aversivas e diminui após a extinção do aprendizado. Entretanto, outros ritmos cerebrais, como as ondas delta, também estão envolvidos nas respostas comportamentais do medo e nos processos de memória. Desta forma, o ritmo teta, que já foi bastante estudado pelo seu papel no aprendizado e na memória, e o ritmo delta, por seu envolvimento no ciclo sono-vigília, foram investigados considerando a relação causal entre eles. Ainda não está bem estabelecido como os ritmos delta e teta podem juntos contribuir nos processos cognitivos ou como os ritmos do hipocampo podem influenciar ou receber influencias da atividade cortical. Neste trabalho foi investigada a contribuição dos ritmos delta e teta em função do estado comportamental (vigília ativa ou congelamento) e do tipo de memória evocada (recente ou remota). Além disso, foi realizada uma análise de sincronia de fase para inferir a dinâmica da atividade elétrica entre o córtex pré-frontal medial, o hipocampo e o córtex visual durante a evocação das memórias de medo. Para tanto, os animais foram treinados e testados numa tarefa de condicionamento de medo ao contexto. Neste tipo de condicionamento, o animal aprende a estabelecer uma associação entre um determinado contexto (caixa de condicionamento) e um evento aversivo (choque elétrico nas patas) que ocorreu neste contexto. Quando o animal foi reintroduzido na caixa de condicionamento, o mesmo exibiu uma série de respostas condicionadas incluindo a reação de congelamento. Os resultados mostraram que os ritmos delta e teta estão relacionados de forma específica às respostas comportamentais de medo e de evocação das memórias recente e remota. Observou-se no espectro de potências uma maior contribuição do ritmo teta durante a vigília exploratória, diminuindo durante o congelamento. Neste último, os ratos apresentaram um robusto aumento da contribuição do ritmo delta. Além disso, a medida de causalidade mostrou ser dependente do estado comportamental do animal. Finalmente, um aumento da sincronia entre o hipocampo e o córtex pré-frontal foi evidenciado durante a evocação de memória recente, contraposta à diminuição durante a evocação da memória remota. Estes resultados indicam que a sincronização da atividade elétrica cerebral pode refletir uma facilitação na comunicação neuronal / The establishment of long-term memories requires effective communication of the hippocampus to the neocortex. Electrophysiological activities between hippocampus and prefrontal cortex have shown higher theta synchronization during retrieval of aversive memories and lower during extinction learning. While theta activity is more differently related to learning and memory, delta waves have been more discussed in the context of sleep or \"offline\" states. Few studies have investigated delta waves during \"on-line\" states (such as task-relevant situations) and the contribution of these rhythms to memory storage remains unclear. We recorded electrophysiological data to study the contributions of delta and theta waves in cortico-hippocampal system of rats underwent to contextual fear conditioning. Our experiment consisted of environmental pre-exposition, training with electrical footshocks, and recent/remote memory tests. Two groups of rats were tested one or eighteen days post training for recent or remote memory, respectively. Local field potential time series of two behavioral states were sampled: active exploration and freezing. The results showed that theta and delta rhythms play an important role in behavioral responses and memory processing. They are related to fear recall and their contribution depend on the recent or remote memory. Additionally, using an order parameter we show that theta contribution is strongly pronounced in active exploration, decreasing during freezing. In the latter, the rats presented pronounced delta waves in freezing. Moreover, a behavioral-dependent causality measure showed an increase of theta influence in delta rhythms, resulting in a theta slowing in aversive memory retrieval. Finally, we show an increased synchrony between hippocampus and prefrontal cortex during recall of recent memory, but a decreased synchrony in remote memory. We proposed that synchronized activity may facilitate the communication of information and once the memories are established in the neocortex, the synchronization decreases, and recalling them becomes more independent of the hippocampus. We proposed that delta-theta oscillations of the hippocampus over neocortical areas reflect information processing during aversive memory retrieval

My doctoral research addressed two questions regarding the influence of orthographic knowledge on speech processing. First, I attempted to identify the locus of the orthographic effects observed in spoken word recognition tasks in which the orthographic consistency and the congruency between the phonological and orthographic representations of the stimuli were manipulated. Several studies provided converging results suggesting that only phonological representations activated at lexical or postlexical processing levels are affected by orthographic knowledge, while those activated at prelexical levels are not. However, the lexical processing level is not the only factor that determines the occurrence and/or the size of the orthographic effects. Regardless of the processing level tapped by the task, the characteristics of the material and the way in which participants perform the tasks also play an important role. Second, I examined the generality of the orthographic effects both in the suprasegmental domain and in the operation of working memory. Overall, the results showed orthographic effects in both situations./La question de l’influence des connaissances orthographiques sur le traitement de la parole a été abordée sous différents angles à travers les études menées dans le cadre de ma thèse de doctorat. Plus précisément, le locus des effets orthographiques a été examiné dans des tâches de reconnaissance de la parole grâce à une manipulation de la consistance orthographique et de la congruence entre les représentations phonologique et orthographique des stimuli. Les résultats obtenus convergent pour indiquer que seules les représentations phonologiques activées dans les situations qui exigent un traitement lexical et/ou post-lexical sont affectées par les représentations orthographiques. Cependant, l’occurrence et/ou la magnitude des effets orthographiques obtenus semblent dépendre également des caractéristiques du matériel et de la manière dont les participants effectuent la tâche. La question de la généralité des effets orthographiques a aussi été abordée :les effets orthographiques ont été démontrés d’une part dans le domaine suprasegmental (sur le ton lexical) et, d’autre part, dans le fonctionnement de la mémoire de travail. / Doctorat en sciences psychologiques / info:eu-repo/semantics/nonPublished

Ce travail de thèse vise à améliorer notre compréhension des mécanismes sous-tendant la perception et la mémorisation des structures sonores complexes. Nous avons étudié les corrélats comportementaux et cérébraux de la perception et de la mémoire auditive pour des notes isolées, des séquences musicales et des séquences de mots, chez des auditeurs typiques et dans l'amusie congénitale, un trouble permanent de la perception de la musique. En utilisant des approches comportementales, nous avons démontré que les déficits des individus amusiques dans la dimension de la hauteur sont liés à des déficits à la fois durant l’encodage des sons courts et dans la rétention à court terme de l'information musicale. En utilisant des mesures neurophysiologiques (IRM, MEG, IRMf) nous avons démontré l’existence d’anomalies anatomiques et fonctionnelles dans le cerveau amusique, principalement dans les cortex frontal et auditif droits. De plus des anomalies fonctionnelles ont été observées à la fois durant l'encodage, la rétention et la reconnaissance de l'information mélodique lors d’une tâche de mémoire à court terme. En revanche, pour le matériel verbal, les participants amusiques recrutaient des régions cérébrales similaires à celles des contrôles, ceci suggérant que des ressources neuronales distinctes sous-tendent la mémoire tonale et verbale. A partir des conclusions de ces trois premières études, nous avons exploré deux approches visant à renforcer les capacités de traitement de la hauteur dans l'amusie: 1) en étudiant si des connaissances implicites du système musical occidental tonal pouvaient améliorer leurs capacités de mémoire à court terme pour les notes, et 2) en explorant si les capacités d’encodage altérées des participants amusiques pouvaient être améliorées par des interactions audio-visuelles. Ces études ont été encourageantes et pourraient guider la conception d'outils de réhabilitation dans ce déficit. Enfin, il convient de souligner que nos recherches contribuent également à améliorer la compréhension des mécanismes sous-tendant le traitement de la musique en général, un domaine de recherche émergeant qui fait le parallèle avec le traitement du langage / The aim of this PhD thesis is to further our understanding about how humans perceive and nmemorize complex sound structures. We investigated the behavioral and cerebral correlates of auditory perception and memory for isolated tones, musical sequences, and verbal material both in typical listeners and in individuals presenting a lifelong disorder of music perception that has been referred to as congenital amusia. Using behavioral approaches, we demonstrated that amusic individuals’ deficits in the pitch dimension are related to impairments both in the encoding of short tones and in the short term retention of pitch information. Using multimodal neuroimaging methods (MRI, MEG, fMRI) we observed anatomical and functional abnormalities in the amusic brain, mostly in the right frontal cortex and in the right auditory cortex. Functional abnormalities were observed at each level of processing in short-term memory tasks, that is for encoding, retention, and retrieval of the melodic information. In contrast, for verbal material, amusic participants recruited similar brain regions as those observed for controls, thus suggesting that separate neural resources support tonal and verbal memory. Based on the conclusions made on these first three studies, we explored two approaches aiming to boost pitch processing abilities in amusia; 1) by investigating whether implicit knowledge of the western tonal musical system could influence their short-term memory abilities, and 2) by exploring whether amusic individuals’ altered encoding of short tones could be improved by audio-visual interactions These investigations were encouraging and provide the first steps toward designing tools of rehabilitation in this musical disorder. To conclude, it is worth underlining that these studies also improve our understanding of music processing in general, which is the subject of an increasing research domain that is often making the parallel to language processing

Le trouble développemental du langage ou la dysphasie se définit comme étant un trouble qui affecte l’acquisition normale du langage oral. Plusieurs sphères du langage peuvent ainsi être affectées à différents degrés. Des difficultés phonologiques, morphosyntaxiques, lexicales et pragmatiques sont constatées chez cette population d’enfants, et ce, tant dans le volet expressif que réceptif. Ces difficultés se manifestent tôt dans la petite enfance et la plupart d’entre elles persistent malgré une prise en charge rééducative importante. Des difficultés d’acquisition de la langue écrite sont également signalées chez ces apprenants. Cela n’est pas surprenant dans la mesure où l’acquisition du code écrit français requiert des connaissances solides de la langue parlée alors qu’un corpus important de données empiriques soutient que les élèves dysphasiques abordent l’acquisition de la langue écrite avec des connaissances orales appauvries. Bien qu’une grande partie de ces données proviennent des travaux anglophones, certains consensus se dégagent et soutiennent l’idée de la présence des difficultés en lecture, plus particulièrement en identification de mots, mais aussi en compréhension en lecture. Les difficultés en production écrite, bien que moins documentées, sont observées, notamment dans les compétences de planification, de génération des idées, mais aussi de révision et de correction d’une production écrite. Les habiletés de production orthographique seraient également inférieures aux normes attendues. S’il est admis que les difficultés d’identification et de production de mots écrits isolés seraient expliquées par une incapacité à emmagasiner et à récupérer les représentations orthographiques dans le lexique orthographique, peu d’études ont porté sur la construction de ce lexique chez l’élève dysphasique francophone. Les conclusions issues des études anglophones doivent être interprétées avec prudence dans la mesure où les deux codes orthographiques présentent des particularités. Bien que le but premier de cette étude exploratoire soit de décrire les compétences orthographiques chez la population d’élèves dysphasiques, nous aimerions aussi comprendre quels sont les facteurs influant sur ce développement. Il est actuellement admis que les habiletés de conscience phonologique, les habiletés de dénomination rapide, les habiletés de mémoire à court terme verbale seraient très prédictives de l’acquisition de la lecture-écriture. D’autres facteurs sont également reconnus comme étant prédictifs de la réussite en lecture-écriture, notamment les habiletés visuoattentionnelles, les habiletés de mise en correspondance graphophonologique ou encore les capacités d’automatisation. Prenant appui sur un corpus important de données suggérant l’existence des difficultés phonologiques chez l’élève dysphasique, dans cette étude nous aimerions vérifier si ces déficits expliqueraient les faibles connaissances orthographiques chez cet apprenant. L’objectif principal de cette étude consiste à décrire les connaissances orthographiques chez l’élève dysphasique francophone du primaire. Trois objectifs spécifiques découlent du principal objectif : 1) Décrire les connaissances orthographiques de l’élève dysphasique ; 2) Identifier si les scores en production de mots écrits sont reliés à d’autres épreuves ayant recours aux connaissances orthographiques telles que la reconnaissance de mots et de pseudo-mots et la compréhension en lecture et 3) Identifier si des facteurs phonologiques tels que la mémoire à court terme verbale, la conscience phonologique, la mise en correspondance phonologique ainsi que la dénomination rapide sont liées aux représentations orthographiques chez l’enfant dysphasique. Une approche méthodologique à groupes comparatifs a été employée dans l’étude pour analyser les performances de trois groupes de participants de l’échantillon à l’étude : 1) un groupe expérimental incluant les élèves présentant un trouble développemental du langage sévère (DYS, N = 25, âge moyen = 9,72), 2) un groupe contrôle apparié selon le niveau de lecture (CL, N = 26) et 3) et un groupe contrôle apparié selon l’âge chronologique (CA, N = 42). Les résultats de cette étude exploratoire suggèrent que les performances en production orthographique des élèves dysphasiques s’apparentent à celles des élèves plus jeunes du groupe CL. De plus, les élèves dysphasiques semblent présenter des performances inférieures aux épreuves évaluant les habiletés phonologiques, notamment la mémoire à court terme verbale, la conscience phonologique, la dénomination rapide et automatisée et la mise en correspondance graphophonologique, en montrant, une fois de plus, des performances similaires à celles des élèves du groupe CL. Enfin, la présence de liens hétérogènes entre les scores aux épreuves phonologiques et à celles évaluant les connaissances orthographiques indiquerait que les connaissances phonologiques ne sont pas entièrement responsables du retard dans le développement de la compétence orthographique chez les apprenants dysphasiques. / Developmental Language Disorder (DLD) is a condition that affects the standard acquisition of oral language. Several spheres of language can be affected to different degrees. Phonological, morphosyntactic, lexical and pragmatic difficulties can be observed in the sample of children affected by DLD, on both expressive and receptive aspects. Such difficulties manifest themselves in early childhood and most of them stay consistent, despite rehabilitative measures being taken. Difficulties in acquiring writing abilities are also identified in those learners’ process. These challenges are not surprising considering that French written code requires a strong knowledge of spoken language and a large body of empirical data suggests that students affected by DLD approach the learning process with poor oral capacities. Although a large part of this data comes from works published in English, some consensuses diverge and suggest the presence of challenges in reading skills, more specifically in word identification, but also in reading comprehension. Writing challenges, although less documented, are also observed, notably in planning skills, expressing ideas, but also in the revision and correction steps of a written piece. Orthographic production abilities could also be inferior to standardized norms. If identification and isolated word production challenges would be explained by an inability to store and reuse orthographic representations in the orthographic lexicon, few studies were oriented on the French dysphasic student’s construction of this lexicon. Studies conducted on English samples must be carefully interpreted, as French and English have very different orthographic codes with each their particularities. The main goal of this exploratory study is to describe the orthographic competences of dysphasic students and comprehend what factors are influencing their language development. It is currently considered that phonological awareness, rapid automatized naming and short-term verbal memory abilities could very well predict the learning process of reading and writing. Other factors are recognized to predict success in reading and writing, notably visuoattentional skills, graphophonological processes or also automatization capacities. Relying on a large body of data suggesting the existence of phonological difficulties experienced by dysphasic students, this study will try to verify if those deficits explain the poor orthographical knowledge of those learners. The main goal of this study is to describe the orthographical knowledge of French elementary school students affected by DLD. Three goals are derivatives of the main one: 1) Describing the orthographical knowledge of the dysphasic student; 2) Identify if the written word production results are related to other tests using orthographical knowledge such as word/pseudo-word recognition and reading comprehension and 3) Identify if phonological factors such as short term verbal memory, phonological awareness, graphophonological processes as well as rapid automatized naming are related to the dysphasic student’s orthographical representation. A group comparative methodological approach was used in this study in order to analyze the results of three groups of participants of the study sample : 1) an experimental group including students with severe DLD (DYS, N = 25), 2) a controlled group matched according to reading skill level (CL, N = 26) and a controlled group matched according to chronological age (CA, N = 42). This exploratory study’s results suggest that the dysphasic students’ performances in orthographical production are similar to those of the younger students of group CL. Furthermore, students affected by DLD seem to score inferior results in tests evaluating phonological abilities, notably short term verbal memory, phonological conscience, rapid automatized naming and graphophonological processes, again demonstrating results similar to those of students of group CL. Conclusively, heterogenic and discordant links between the French dysphasic elementary school learners’ scores in phonological tests and orthographical knowledge tests show that phonological knowledge is not entirely the cause of delays in the development of their orthographical skills.

Traffic congestion is a severe problem in urban areas and it leads to the emission of greenhouse gases and air pollution. In general, drivers lack knowledge of the location and availability of free parking spaces in urban cities. This leads to people driving around searching for parking places, and about one-third of traffic congestion in cities is due to drivers searching for an available parking lot. In recent years, various solutions to provide parking information ahead have been proposed. The vast majority of these solutions have been applied in large cities, such as Beijing and San Francisco. This thesis has been conducted in collaboration with Knowit and Dukaten to predict parking occupancy in car parks one hour ahead in the relatively small city of Linköping. To make the predictions, this study has investigated the possibility to use long short-term memory and gradient boosting regression trees, trained on historical parking data. To enhance decision making, the predictive uncertainty was estimated using the novel approach Monte Carlo dropout for the former, and quantile regression for the latter. This study reveals that both of the models can predict parking occupancy ahead of time and they are found to excel in different contexts. The inclusion of exogenous features can improve prediction quality. More specifically, we found that incorporating hour of the day improved the models’ performances, while weather features did not contribute much. As for uncertainty, the employed method Monte Carlo dropout was shown to be sensitive to parameter tuning to obtain good uncertainty estimates.