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This thesis explores implicit learning in children with developmental dyslexia. While specific cognitive abilities such as phonology and memory have been extensively explored in developmental dyslexia more global, fundamental abilities are rarely studied. A literature review is reported, which indicates that there is a gap in the study of more generic abilities highlighting at the same time, the need of investigating developmental dyslexia in the kind of contemporary context that learning literature provides. Implicit learning seems a suitable paradigm case to explore global abilities in developmental dyslexia since there have been suggestions that learning becomes more implicit in nature after explicit instruction. Based on the proposed relationship between implicit learning and reading, it is argued that impairments in the mechanisms of implicit learning could mediate selective weaknesses in reading performance in developmental dyslexia. The present thesis tests this argument in a series of three studies that are composed of five linked experiments. Together the three studies reported in the present thesis provide evidence for the implicit learning abilities in children with and without developmental dyslexia. The results suggest that while implicit learning abilities are found intact in typically developing children, children with developmental dyslexia on the other hand, might be facing an implicit learning deficit that could affect their reading performance and inhibit them from reaching their full learning potential.

Background: Developmental dyslexia is a wide-ranging and persistent neurobiological disorder classified under specific learning disorders. The literature widely recognises the multifactorial nature of developmental dyslexia, specifically the language-related origin. Objectives: The current review systematically identified and synthesised possible language-based risk factors associated with developmental dyslexia in children (age one to three and four to ten years) and determined the level of evidence associated with these risk factors. The review aimed to identify individualised risk factors in children with developmental dyslexia to promote optimal neurodevelopmental outcomes. Method: Four relevant databases were searched from January 2002 until December 2018. A hand search of the included articles’ reference lists was also performed to identify any relevant publication. The language-based risk factors in children with developmental dyslexia in 48 publications were studied. Results: All language components are compromised to some degree in children with developmental dyslexia at specific ages. These results indicate the intricacy of language, but also emphasise that developmental dyslexia should be considered on a continuum and not as an absolute disorder. Only a few studies investigated language-based risk factors in participants five years and younger. Phonological-based risk factors were the most reported language component and comprise of risk factors within phonological awareness, rapid automized naming, and working memory. The second language component entailed morphology. Several inflectional and derivational morphological risk factors, as well as risk factors within syntactic processing, were acknowledged. Compromised receptive and expressive vocabulary knowledge, semantic processing, and fluency were identified as risk factors for the language component of semantics. The final component of language entailed pragmatics. Unfortunately, a limited amount of evidence is available in this regard. However, the evidence available confirmed poor linguistic pragmatics as a risk factor in children with developmental dyslexia. Conclusion: These language components are interrelated and should be viewed holistically as risk factors for developmental dyslexia to promote earlier identification. / Dissertation (MA)--University of Pretoria, 2019. / Speech-Language Pathology and Audiology / MA / Unrestricted

Esta pesquisa teve como objetivo analisar e comparar o desempenho no WISC-III de crianças com dislexia do desenvolvimento com o de dois grupos controle, a fim de verificar a existência de características específicas no desempenho desta escala no grupo com dislexia. Ao todo foram 57 sujeitos, divididos entre o grupo dos disléxicos (n=20), o grupo controle 1 (GC1) formado por crianças sem queixa de dificuldade escolar da mesma idade cronológica e série dos disléxicos (n=21), e grupo controle 2 (GC2) formado por alunos do segundo ano do Ensino Fundamental, que ainda estavam no processo inicial de aprendizagem da leitura e da escrita (n=16). Os dados do grupo dos disléxicos foram coletados a partir dos registros da Clínica Psicológica da Universidade Estadual de Londrina, em que constava o diagnóstico de dislexia no período de 2006 a 2011. Para o delineamento dos grupos controle, levou-se em consideração também a escola em que os disléxicos estavam matriculados na época da avaliação (estadual, municipal e particular). Para análise estatística, foi utilizado o programa SPSS para Windows, sendo que a significância adotada foi menor que 0,05. Quanto aos resultados, o grupo dos disléxicos, quando comparado aos dois grupos controle, teve pior desempenho nas Escalas de Resistência à Distração e Velocidade de Processamento. Pesquisas mostram que os disléxicos geralmente apresentam baixo desempenho em alguns subtestes, descrito como perfil ACID. Nesta pesquisa, o grupo dos disléxicos teve desempenho menor que os dois grupos controle nos subtestes Dígitos, Código e Procurar Símbolos, mas este dado não foi encontrado no subteste Aritmética. O desempenho dos disléxicos também foi menor nos subtestes Informação e Semelhanças, mas apenas em comparação ao GC1, o que sugere que esse resultado seja devido à dificuldade escolar do disléxico vivenciada através dos anos. Comparando-se as escolas, os alunos da escola particular tiveram melhor desempenho no subteste Códigos e pior desempenho no subteste Armar Objetos apenas em relação aos alunos da escola estadual. Como o grupo da escola particular foi muito pequeno, acredita-se que isso seja uma variação referente a este grupo específico de alunos. Quanto à comparação entre os disléxicos do sexo feminino e masculino, e com e sem TDAH, não foram encontradas diferenças estatisticamente significativas no desempenho dos subtestes. Concluindo, os dados da pesquisa coincidem com algumas pesquisas feitas de que parece haver um perfil dos disléxicos, que possuem menor desempenho nos subtestes que avaliam atenção visual e memória de trabalho. Entretanto, ao contrário dessas pesquisas, acredita-se que o menor desempenho no subteste Informação não seja uma característica peculiar dos disléxicos, mas sim consequência de sua dificuldade escolar / This study aimed to analyze and compare the performance on WISC-III in children with developmental dyslexia with the two control groups in order to check for specific performance characteristics of this scale in the group with dyslexia. Altogether, there were 57 subjects, divided between the group of dyslexics (n = 20), the control group 1 (GC1) formed by children without school difficulties of the same chronological age and grade of dyslexics (n = 21) and control group 2 (CG2) formed by students of the second year of elementary school, that were still in the initial process of reading and writing (n= 16). Data from the group of dyslexics were collected from the records of the Psychological Clinic at the Universidade Estadual de Londrina, which appeared the diagnosis of dyslexia in the period from 2006 to 2011. For the design of the control groups, the school that dyslexics were enrolled at the time of assessment (state, municipal and private) was considered. Statistical analysis was performed using the SPSS program for Windows, and the significance adopted was less than 0.05. As for the results, the group of dyslexics when compared to control groups had lower performance in sub scales Freedom from Distractibility and Processing Speed. Research shows that dyslexics often have low performance on some subtests, described as ACID profile. In this study, the dyslexic group had lower performance than the two control groups on Digit Span, Coding and Symbol Search, but this finding was not found in the Arithmetic subtest. The performance of dyslexics was also lower in Information and Similarities subtests, but only compared to the GC1, suggesting that this result is due to the difficulty of dyslexic school experienced through the years. Comparing schools, students in private schools performed better on subtest Coding and poorer performance on subtest Object Assembly only in relation to students of state school. As the private school group was very small, it is believed that this is a variation regarding this particular group of students. Regarding the comparison between dyslexics female and male, and with and without ADHD, there were no statistically significant differences. In conclusion, the survey data coincide with some research done that there seems to be a profile of dyslexics, who have lower performance in the tests that assess visual attention and working memory. However, unlike these studies, it is believed that the lower performance in the Information subtest is not a peculiar characteristic of dyslexics, but a consequence of their school difficulties

The procedural deficit hypothesis (PDH) posits that a range of language, cognitive and motor impairments associated with specific language impairment (SLI) and developmental dyslexia (DD) may be explained by an underlying domain-general dysfunction of the procedural memory system. In contrast, declarative memory is hypothesized to remain intact and to play a compensatory role in the two disorders. The studies in the present thesis were designed to test this hypothesis. Study I examined non-language procedural memory, specifically implicit sequence learning, in children with SLI. It was shown that children with poor performance on tests of grammar were impaired at consolidation of procedural memory compared to children with normal grammar. These findings support the PDH and are line with previous studies suggesting a link between grammar processing and procedural memory. In Study II, the same implicit sequence learning paradigm was used to test procedural memory in children with DD. The DD group showed a learning profile that was similar to that of children with SLI in Study I, with a significant impairment emerging late in learning, after extended practice and including an overnight interval. Further analyses suggested that the DD impairment may not be related to overnight consolidation but to the effects of further practice beyond the initial practice session. In contrast to the predictions of the PDH, the sequence learning deficit was unrelated to phonological processing skills as assessed with a nonword repetition task. Study III examined declarative memory in DD. The performance of the DD group was found to be not only intact, but even enhanced, compared to that of the control children. The results encourage further studies on the potential of declarative memory to compensate for the reading problems in DD. In sum, the results lend partial support for the PDH and suggest further refinements to the theory. Collectively, the studies emphasize the importance of going beyond a narrow focus on language learning and memory functions in the characterization of the two disorders. Such a broader cognitive, motor and language approach may inform the development of future clinical and pedagogical assessment and intervention practices for SLI and DD.

Made available in DSpace on 2016-03-15T19:41:19Z (GMT). No. of bitstreams: 1 Anna Carolina Cassiano Brabosa.pdf: 1148993 bytes, checksum: a240fc0effdaa5732859d8fabc86f715 (MD5) Previous issue date: 2013-01-22 / Fundo Mackenzie de Pesquisa / The developmental dyslexia is a learning disorder that includes behavioral and cognitive disorders such as slow reading and reversals errors of letters and syllables. The analysis of physiological measures during reading can help to understand the deficits present by dyslexics. The main physiological measures related to visual analysis of read items include: patterns of eye movements and pupil diameter variations. This study aims to analyze behavioral and physiological measures of good readers and dyslexics during reading of texts. The study included 16 children, 8 of whom were dyslexic and 8 good readers, with an average age of 10.71 years (sd = 1.799) and 10.57 years (sd= 1,761) respectively. The subjects read four different texts on a computer screen with equipment for analyzing eye movements. The results revealed that dyslexics presented worse than good readers on tests of reading, spelling and phonological awareness. Thus dyslexics have difficulties in the rapid identification of words, confusions committed by visual and auditory similarity, and demonstrate losses in phonological awareness. Additionally, took longer to complete tasks. Analysis of physiological measurements reveal the average duration of fixations was greater for dyslexics. Analysis of pupillary variance indicates that good readers showed no change in pupil diameter in four texts but dyslexics presented pupil contraction in Text 1. / A dislexia do desenvolvimento é um distúrbio de aprendizagem que abrange alterações comportamentais e cognitivas tais como leitura lenta e com erros de inversões de letras e sílabas. A análise de medidas fisiológicas durante a leitura pode auxiliar na compreensão dos déficits apresentados por disléxicos. Dentre as principais medidas fisiológicas relacionadas com a análise visual dos itens lidos destacam-se padrões de movimentos oculares e variações do diâmetro pupilar. O presente trabalho tem como objetivo analisar medidas comportamentais e fisiológicas de disléxicos e bons leitores durante a leitura de textos. Participaram do estudo 16 crianças, sendo 8 disléxicos e 8 bons leitores, com idade média de 10,71 anos (dp=1,799) e 10,57 anos (dp= 1,761) respectivamente. Os sujeitos leram 4 textos diferentes na tela de um computador com equipamento de análise dos movimentos oculares. Os resultados revelaram que disléxicos apresentaram desempenho inferior aos bons leitores nas provas de leitura, escrita e consciência fonológica. Assim, disléxicos apresentam dificuldades na identificação rápida de palavras, cometeram confusões por semelhança visual e auditiva, e demonstram prejuízos em consciência fonológica. Além disso, levaram mais tempo para executar as tarefas. Análises das medidas fisiológicas revelam que a duração média das fixações foi maior para os disléxicos. Análise da variação pupilométrica indica que bons leitores não apresentaram variação no diâmetro da pupila nos 4 textos, mas os disléxicos apresentaram contração pupilar no Texto 1.

Esta pesquisa teve como objetivo analisar e comparar o desempenho no WISC-III de crianças com dislexia do desenvolvimento com o de dois grupos controle, a fim de verificar a existência de características específicas no desempenho desta escala no grupo com dislexia. Ao todo foram 57 sujeitos, divididos entre o grupo dos disléxicos (n=20), o grupo controle 1 (GC1) formado por crianças sem queixa de dificuldade escolar da mesma idade cronológica e série dos disléxicos (n=21), e grupo controle 2 (GC2) formado por alunos do segundo ano do Ensino Fundamental, que ainda estavam no processo inicial de aprendizagem da leitura e da escrita (n=16). Os dados do grupo dos disléxicos foram coletados a partir dos registros da Clínica Psicológica da Universidade Estadual de Londrina, em que constava o diagnóstico de dislexia no período de 2006 a 2011. Para o delineamento dos grupos controle, levou-se em consideração também a escola em que os disléxicos estavam matriculados na época da avaliação (estadual, municipal e particular). Para análise estatística, foi utilizado o programa SPSS para Windows, sendo que a significância adotada foi menor que 0,05. Quanto aos resultados, o grupo dos disléxicos, quando comparado aos dois grupos controle, teve pior desempenho nas Escalas de Resistência à Distração e Velocidade de Processamento. Pesquisas mostram que os disléxicos geralmente apresentam baixo desempenho em alguns subtestes, descrito como perfil ACID. Nesta pesquisa, o grupo dos disléxicos teve desempenho menor que os dois grupos controle nos subtestes Dígitos, Código e Procurar Símbolos, mas este dado não foi encontrado no subteste Aritmética. O desempenho dos disléxicos também foi menor nos subtestes Informação e Semelhanças, mas apenas em comparação ao GC1, o que sugere que esse resultado seja devido à dificuldade escolar do disléxico vivenciada através dos anos. Comparando-se as escolas, os alunos da escola particular tiveram melhor desempenho no subteste Códigos e pior desempenho no subteste Armar Objetos apenas em relação aos alunos da escola estadual. Como o grupo da escola particular foi muito pequeno, acredita-se que isso seja uma variação referente a este grupo específico de alunos. Quanto à comparação entre os disléxicos do sexo feminino e masculino, e com e sem TDAH, não foram encontradas diferenças estatisticamente significativas no desempenho dos subtestes. Concluindo, os dados da pesquisa coincidem com algumas pesquisas feitas de que parece haver um perfil dos disléxicos, que possuem menor desempenho nos subtestes que avaliam atenção visual e memória de trabalho. Entretanto, ao contrário dessas pesquisas, acredita-se que o menor desempenho no subteste Informação não seja uma característica peculiar dos disléxicos, mas sim consequência de sua dificuldade escolar / This study aimed to analyze and compare the performance on WISC-III in children with developmental dyslexia with the two control groups in order to check for specific performance characteristics of this scale in the group with dyslexia. Altogether, there were 57 subjects, divided between the group of dyslexics (n = 20), the control group 1 (GC1) formed by children without school difficulties of the same chronological age and grade of dyslexics (n = 21) and control group 2 (CG2) formed by students of the second year of elementary school, that were still in the initial process of reading and writing (n= 16). Data from the group of dyslexics were collected from the records of the Psychological Clinic at the Universidade Estadual de Londrina, which appeared the diagnosis of dyslexia in the period from 2006 to 2011. For the design of the control groups, the school that dyslexics were enrolled at the time of assessment (state, municipal and private) was considered. Statistical analysis was performed using the SPSS program for Windows, and the significance adopted was less than 0.05. As for the results, the group of dyslexics when compared to control groups had lower performance in sub scales Freedom from Distractibility and Processing Speed. Research shows that dyslexics often have low performance on some subtests, described as ACID profile. In this study, the dyslexic group had lower performance than the two control groups on Digit Span, Coding and Symbol Search, but this finding was not found in the Arithmetic subtest. The performance of dyslexics was also lower in Information and Similarities subtests, but only compared to the GC1, suggesting that this result is due to the difficulty of dyslexic school experienced through the years. Comparing schools, students in private schools performed better on subtest Coding and poorer performance on subtest Object Assembly only in relation to students of state school. As the private school group was very small, it is believed that this is a variation regarding this particular group of students. Regarding the comparison between dyslexics female and male, and with and without ADHD, there were no statistically significant differences. In conclusion, the survey data coincide with some research done that there seems to be a profile of dyslexics, who have lower performance in the tests that assess visual attention and working memory. However, unlike these studies, it is believed that the lower performance in the Information subtest is not a peculiar characteristic of dyslexics, but a consequence of their school difficulties

The purpose of this study was to explore the possibility that music and movement instruction could cause improvement in language arts skills, due to evidence that music and language share processing mechanisms related to auditory perception as described by Patel (2007, 2011a, 2011b, 2014) in the shared syntactic integration resource hypothesis (SSIRH) and OPERA hypothesis. Sixty-two Kindergarten students from a suburban school, near a city in the Midwest, were selected via random assignment to be a part of an experimental or control group. Each group participated in pre- and posttests measuring entrainment and pre-reading skills. ANCOVA results of pre and posttest data revealed no significant difference between the groups. The music and movement instruction did not improve entrainment so results were inconclusive in regard to the impact of entrainment on phonological processing and rapid naming. Future studies might consider a pretest/posttest design with a group that focuses on entrainment without specific music language (Patel, 2008) and a group that conducted music class with the usual songs and descriptive language, to provide evidence regarding whether or not language needs to be combined with music to cause a cognitive transfer of skills. A further comparison of a group that learned to play singing games with a group that learned instrumental music might provide further evidence regarding the role that the combination of music and language might have on reading. Another line of inquiry might involve increasing the length of the intervention period to determine if a year is needed to cause cognitive transfer and ensure that the control group does not receive any music instruction. An additional consideration may be that improvement in entrainment provides a foundation for language processing that does not fully develop or present itself until children reach more challenging levels of reading fluency. Studies that measure student improvement over time would be one way to find evidence that music provides a neurological basis for reading, and language development. Further study possibilities are described in the conclusions of the dissertation. / 2022-11-15T00:00:00Z

Developmental Dyslexia (DD), Attention Deficit Hyperactivity Disorder (ADHD), and Educational Attainment (EA) are highly prevalent conditions that have a significant impacton individuals' academic and social functioning. These conditions have a complex genetic basis and are often comorbid. To assess the polygenic architecture of these traits, psychiatric genetics researchers utilize a sophisticated tool known as polygenic scores (PGS). By combining numerous genes of individually modest effects, PGS summarizes an individual's genetic risk as a single score. In this study, we aimed to examine the association between PGS for ADHD and EA with typical DD traits. Using a meta-analytic approach, we analyzed data from earlier studies and found that PGS-ADHD accounts for 1.2% of the variance in DD, with a pooled effect size of r = -0.11 (95% CI = [-0.171, -0.050]). Similarly, PGS-EA accounted for 3.2% of the variance in DD, with a pooled effect size of r = 0.18 (95% CI = [0.070, 0.288]). Although these effect sizes are relatively small, it is important to note that PGS are not typically strong predictors on their own, but rather capture a small portion of the genetic variation that contributes to a trait or outcome. My findings suggest that PGS for ADHD and EA are associated with DD, indicating that DD has a complex genetic basis. However, these findings also raise questions about the impact of PGS on psychiatric research moving forward. To address these questions, I provide recommendations for future researchdirections.

La lecture et l’écriture sont deux activités complexes qui contribuent à la réussite dans toutes les disciplines scolaires. Pour l’apprenti scripteur, et plus particulièrement pour l’élève qui éprouve des difficultés d’apprentissage (notamment l’élève dyslexique), l’apprentissage de l’orthographe représente un réel défi et nécessite souvent des années d’effort. Or, la connaissance du code orthographique constitue le socle sur lequel se construit la compétence orthographique. La reconnaissance et la production de mots écrits impliquent la mise en place d’un noyau de connaissances communes se rapportant aux connaissances orthographiques, c’est-à-dire aux connaissances rattachées aux propriétés phonologiques, morphologiques et visuelles du code orthographique. Ainsi, tout au long du développement de la compétence orthographique, le lecteur-scripteur doit notamment construire des représentations orthographiques de plus en plus stables et mieux définies qui tiennent compte de l’ensemble des propriétés du code orthographique. Des données empiriques récentes indiquent toutefois que les élèves dyslexiques, qui commettent davantage d’erreurs orthographiques de fusion et de segmentation de mots que les élèves sans difficulté à l’écrit, ne semblent pas disposer de représentations orthographiques précises des mots à orthographier, et plus spécifiquement de bonnes représentations du début et de la fin des mots. L’objectif général de cette étude est donc d’expliquer les erreurs orthographiques de frontières lexicales chez les élèves dyslexiques. Comme à notre connaissance, il n’existe pas de norme quant au développement des connaissances des frontières lexicales chez les élèves normo-lecteurs/scripteurs, le premier objectif spécifique est de décrire, de façon transversale et longitudinale, les performances d’élèves normo-lecteurs/scripteurs de la maternelle à la 4e année du primaire à des épreuves évaluant les connaissances des frontières lexicales (étude 1). La mise en place de cette référence développementale a permis de répondre au deuxième objectif spécifique qui est d’évaluer les connaissances des frontières lexicales d’élèves dyslexiques du primaire (étude 2). Pour évaluer les compétences en lecture et en production de mots, une épreuve de lecture de la batterie de tests du K-ABC et une dictée de mots insérés en contexte phrastique ont été proposées. Trois épreuves (décision lexicale, identification lexicale et permutation lexicale), variant en termes de degré de contraintes cognitives, ont été effectuées par tous les participants à l’oral et à l’écrit afin d’évaluer leurs connaissances des frontières lexicales. / Reading and writing are two complex activities that contribute to success in all school subjects. For apprentice writers, and particularly for students with learning difficulties (notably students with dyslexia), learning to spell represents a real challenge and often requires years of effort. To be successful, students require knowledge of the orthographic code, which is the foundation upon which spelling ability it built. To recognize and produce written words, students must develop a set of core skills that are linked to orthographic knowledge, including knowledge of the phonological, morphological and visual properties of the orthographic code. As their spelling skills develop, readers and writers must construct increasingly stable and better defined orthographic representations that reflect the properties of the orthographic code. However, recent empirical research has found that students with dyslexia, who tend to make more errors related to word merging and segmentation than students without writing difficulties, do not seem to have accurate orthographic representations of the words they are trying to spell, particularly of the beginnings and endings of words. Therefore, the general aim of this study is to explain spelling errors occurring at word boundaries in dyslexic children. To our knowledge, no typical trajectory of development has been established for normally-developing readers/writers with regards to knowledge of lexical boundaries. Therefore, using both cross-sectional and longitudinal analyses, this study’s first objective is to describe the performances of normally-developing reader and writers from kindergarten to grade 4 on tasks related to lexical boundary knowledge (Study 1). With this developmental reference having been established, the second study will evaluate lexical boundary knowledge in primary school students with dyslexia (study 2). To evaluate ability in reading and word production, a reading test from the K-ABC battery and a dictation task requiring students to insert words in the context of a sentence were administered. To evaluate knowledge of lexical boundaries, three tasks (a lexical decision task, a lexical identification task, and a lexical permutation task) were completed by all participants in oral and written form, each of which varied according to the level of cognitive constraint involved in completing the task.