Manifestation Of Dyslexia Research Articles

Developmental dyslexia: Convergence of all theories towards a multifactional model, and the role of ICTs

Dyslexia is a neurodevelopmental disorder that is characterised by slow and inaccurate word recognition. This article intends to summarize the current understanding of developmental dyslexia's etiology, brain bases, neuropsychology, and social context. In this article are discussed the progress has been made the last years in domains involving definition and classification, neuropsychological correlates, neurobiological factors, and intervention of dyslexia. It is also referred to the neuropsychological approaches to dyslexia have evolved and the importance of an interdisciplinary perspective for understanding dyslexia. Dyslexia is caused by multiple genetic and environmental risk factors as well as their interplay. Several candidate genes have been identified in the past decade. At the brain level, dyslexia is associated with aberrant structure and function, particularly in left hemisphere reading/language networks. The neurocognitive influences on dyslexia are also multifactorial and involve phonological processing deficits as well as weaknesses in other oral language skills and processing speed. Contextual issues such as the correlation of dyslexia with an individual’s IQ or age, the manifestation of dyslexia across languages and social classes as well as what treatments are best supported are being examined. This article is aimed at highlighting the exciting new research that cuts across levels of analysis. Such work promises eventually to provide a comprehensive explanation of the disorder as well as its prevention and remediation. In this recent contribution to the field of Dyslexia, we will be mentioned to some historical information, as well as we will be faced with significant issues in the Phonological Theory of Dyslexia. The single versus will multiple deficit accounts. In the field of the etiology of Dyslexia, we will be mentioned to the Behavioural Genetics, to the Molecular Genetics and to Environmental Influences. Individuals with dyslexia show functional abnormalities in both posterior and anterior language networks. This approach is intended to promote scientific knowledge and draws attention to the complexity of the developmental dyslexia (DD).

Etiology and Manifestation of Dyslexia among Grade Six Pupils in Eastern Zambia

The terms dyslexia and reading disability are often used interchangeably. There are so many children who encounter reading problems in Zambia to an extent that some of them might complete seven years of primary education without the ability to read even a three letter word (MoE, 1992).A study conducted in Zambia by MatafWali (2005) revealed that, 49.1% of the grade three pupils could not read words at all. In addition, 57.5% could not read any single sentence. According to Kelly (2000), the reading level in some grade six pupils fell within the level expected of grade four. Therefore, it means that teachers who teach reading to dyslexic pupils face a lot of challenges. It is a well documented factor that-, in the western world, reading disabilities play a major role amongst children who drop out of school and/or become delinquent (Zieman, 1999). In addition, it is important to know the factors which cause dyslexia so as to remediate the problem. The objective of the present study was to identify reading disabilities among grade six pupils and challenges that teachers face in teaching reading to these pupils. Informed consent was obtained from the respondents and then questionnaires were administered to those who agreed to participate in the study. Simple random sampling was used to come up with the required number of pupils using the class registers. Teachers were given questionnaires to answer on their own after they had understood the instructions. For the pupils, questionnaires had to be answered on a one-to-one basis with the researcher. The research design of this study was a quasi experimental design. A total of one hundred and ninety two (192) pupils and fourteen (14) teachers drawn from two districts in eastern Zambia were enrolled in the study. Results show that there was a moderate effect of lighting system at home and one's reading ability (F (10, 154) — 3.188, p < .05, partial = 9.4). As such, the nature of lighting system at home does not really affect

Reading and reading-related skills in adults with dyslexia from different orthographic systems: a review and meta-analysis.

An individual diagnosed with dyslexia in childhood typically remains dyslexic throughout his/her life. However, the cognitive profile of adults with dyslexia has been less explored than that of children. This meta-analytic study is intended to clarify three questions: (1) To what extent, and in what manner, do adults with reading difficulties (dyslexia) differ from typical adult readers in measures of reading and writing competence and related cognitive skills?; (2) To what extent do speed measures pose a greater challenge than accuracy measures in an adult population that has already had years of print exposure?; and (3) To what extent does orthographic transparency modulate the reading profile of adults with dyslexia? A total of 178 studies comparing adults with dyslexia and matched controls were reviewed. The results showed that adults with dyslexia exhibited poor performance on almost all reading and writing tasks expressed by very large effect sizes (range 1.735≤ d ≤2.034), except for reading comprehension (d = 0.729). Deficits in reading- and writing-related variables are also present but with a lower expression (range 0.591≤ d ≤1.295). These difficulties are exacerbated for speed measures, especially for word and pseudoword reading, phonological awareness and orthographic knowledge. Orthographic transparency proved to be a significant moderator of dyslexic deficits in word and pseudoword reading, reading comprehension, spelling and phonological awareness, with the expression of the deficits being weaker on transparent-as opposed to intermediate and opaque-orthographies. Overall, the meta-analysis shows that reading and writing difficulties persist in adulthood and are more pronounced in speed measures. Moreover, symptoms are more severe for reading and writing than they are for measures tapping into the cognitive processes underlying reading skills. Orthographic transparency has a significant effect on the manifestation of dyslexia, with dyslexia symptoms being less marked on transparent orthographies. In addition, phonological awareness seems to be a minor problem in adulthood, especially for transparent orthographies.

Phonological-Orthographic Deficits in Developmental Dyslexia in Three Spanish-English Bilingual Students.

Introduction The purpose of this study is to present three case studies of developmental dyslexia in dual-language learners (DLLs) and our assessment process. We identify how phonological and orthographic deficits influence reading outcomes. We review the literature on theoretical models of bilingualism and reading models of developmental dyslexia to guide the assessment process through a multicomponential approach. We point out differences in the manifestation of dyslexia in more and less transparent writing systems. We suggest that reading instruction in Spanish can afford benefits to English-Spanish DLLs with developmental dyslexia. Method The study included three participants, two in fifth grade (10.3-11.7 years) and one in college (18.7 years). The assessment battery included reading nonwords and sight words (Test of Word Reading Efficiency); reading accuracy, fluency, and comprehension (Gray Oral Reading Tests-Fourth Edition); phonological awareness subtests (Comprehensive Test of Phonological Processing); and rapid automatized naming tests. A language and reading history interview was elicited from the mothers. In addition, we analyzed the participants' phonemic and word errors in reading. Results Our three participants showed core phonological deficits, with decreased performance in decoding nonwords and low accuracy in reading aloud. In spite of their reading and writing deficits, reading comprehension was within average levels for the three participants in this study. Conclusions We show the importance of assessing reading processes in students with a history of reading and writing problems. Our findings are based on three single case studies and are not generalizable. Our aim is to stimulate questions and research on dyslexia and the particular needs of DLLs.

When diglossia meets dyslexia: The effect of diglossia on voweled and unvoweled word reading among native Arabic-speaking dyslexic children

Native Arabic speakers read in a language variety that is different from the one they use for everyday speech. The aim of the present study was: (1) to examine Spoken Arabic (SpA) and Standard Arabic (StA) voweled and unvoweled word reading among native-speaking sixth graders with developmental dyslexia; and (2) to determine whether SpA reading ability among children with dyslexia predicts StA reading fluency in the two orthographies: voweled and unvoweled. A comparison was made to three age groups of typically developing children: a group matched by chronological age, a group of children who are two years younger, and a group of children who are 4 years younger. Findings show that diglossia has a strong impact on reading ability in dyslexic children. Moreover, vowelization plays a pivotal role in the reading ability of Arabic-speaking children with dyslexia in both SpA and StA. This role is evident in the different performance patterns of dyslexic participants as compared with controls on word-reading accuracy and fluency for SpA versus StA. Finally, StA word-reading fluency appears to depend on and to be reliably and powerfully predicted by SpA word-level reading ability. These results underscore the role of diglossia and vowelization in the manifestation of dyslexia in Arabic-speaking children.

Risk and protective factors in gifted children with dyslexia.

This study investigated risk and protective factors associated with dyslexia and literacy development, both at the group and individual level, to gain more insight in underlying cognitive profiles and possibilities for compensation in high-IQ children. A sample of 73 Dutch primary school children included a dyslexic group, a gifted-dyslexic group, and a borderline-dyslexic group (i.e., gifted children with relative literacy problems). Children were assessed on literacy, phonology, language, and working memory. Competing hypotheses were formulated, comparing the core-deficit view to the twice-exceptionality view on compensation with giftedness-related strengths. The results showed no indication of compensation of dyslexia-related deficits by giftedness-related strengths in gifted children with dyslexia. The higher literacy levels of borderline children compared to gifted children with dyslexia seemed the result of both fewer combinations of risk factors and less severe phonological deficits in this group. There was no evidence for compensation by specific strengths more relevant to literacy development in the borderline group. Accordingly, the findings largely supported the core-deficit view, whereas no evidence for the twice-exceptionality view was found. Besides practical implications, the findings also add to knowledge about the different manifestations of dyslexia and associated underlying cognitive factors at the higher end of the intelligence spectrum.Electronic supplementary materialThe online version of this article (doi:10.1007/s11881-015-0106-y) contains supplementary material, which is available to authorized users.

Manifestations of Dyslexia and Dyscalculia

This study examined the prevalence of dyslexia and dyscalculia among persons with academic deficits in English Language and Mathematics in public primary schools in Ibadan metropolis. A correlational survey study, sampling 477 pupils who were between the ages of eight and 12 years, and in 4th and 5th grades with the use of four research instruments- the Myklebust Pupil Rating Scale (MPRS), the Slosson Intelligence Test- Revised Third Edition (SIT-R3), the Test of Pupil Reading Abilities Test (TPRA) and the Mathematical Abilities Test (MAT) was adopted. It was discovered that dyslexia and dyscalculia were prevalent among pupils with academic deficits in English Language and Mathematics, and that pupils with both dyslexia and dyscalculia are in the larger percentage. It was also discovered that learning disabilities, dyslexia and dyscalculia were not peculiar to any gender. Persons with academic deficits in English language and mathematics should be screened for either dyslexia or dyscalculia, even both. Also, they should be taught according to a carefully developed Individualized Education Plan.

Dyslexia in regular orthographies: manifestation and causation

This article summarizes our research on the manifestation of dyslexia in German and on cognitive deficits, which may account for the severe reading speed deficit and the poor orthographic spelling performance that characterize dyslexia in regular orthographies. An only limited causal role of phonological deficits (phonological awareness, phonological STM, and rapid naming) for the emergence of reading fluency and spelling deficits is inferred from two large longitudinal studies with assessments of phonology before learning to read. A review of our cross-sectional studies provides no support for several cognitive deficits (visual-attention deficit, magnocellular dysfunction, skill automatization deficit, and visual-sequential memory deficit), which were proposed as alternatives to the phonological deficit account. Finally, a revised version of the phonological deficit account in terms of a dysfunction in orthographic-phonological connectivity is proposed.

Voices of teachers with dyslexia in Finnish and English further and higher educational settings

This paper sheds light onto a poorly presented group of professionals – teachers with dyslexia in Finnish and English further and higher educational settings. The purpose of this qualitative study was, firstly, to discover what teachers with dyslexia could tell us about the manifestation of dyslexia and the challenges they face in the practice of teaching, and secondly, to find out what these professionals feel about being a dyslexic teacher. The data were gathered through the narrative interviews of six teachers and was analysed using thematic narrative analysis. Teachers’ narratives revealed that they had accepted their difficulties but also discovered their own strengths to overcome them. The data also indicated that these teachers appreciate their educator’s role, acknowledging the importance of empathy and understanding towards their students. Teachers with dyslexia can be successful and useful in training fellow practitioners to be more aware of students’ difficulties with dyslexia, hence having the potential to broaden capacity for inclusion and social equality in educational establishments.

Desempenho em consciência fonológica, memória operacional, leitura e escrita na dislexia familial

familial dyslexia. to characterize and compare the phonological awareness, working memory, reading and writing abilities of individuals whose family members are also affected. in this study 10 familial nuclei of natural family relationship of individuals with dyslexia were analyzed. Families of natural individuals living in the west region of the state of São Paulo were selected. Inclusion criteria were: to be a native speaker of the Brazilian Portuguese language, to have 8 years of age or more, to present positive familial history for learning disabilities, that is, to present at least one relative with difficulties in learning. Exclusion criteria were: to present any neurological disorder genetically caused or not, in any of the family members, such as dystonia, extra pyramidal diseases, mental disorder, epilepsy, attention deficit and hyperactivity disorder (ADHA); psychiatric symptoms or conditions; or any other pertinent conditions that could cause errors in the diagnosis. As for the diagnosis of developmental dyslexia, information about the familial history of the adolescents and children was gathered with the parents, so that a detailed pedigree could be delineated. Neurological, psychological, speech-language, and school performance evaluations were made with the individuals and their families. the results of this study suggest that the dyslexic individuals and their respective relatives, also with dyslexia, presented lower performances than the control group in terms of rapid automatic naming, reading, writing and phonological awareness. deficits in phonological awareness, working memory, reading and writing seem to have genetic susceptibility that possibly determine, when in interaction with the environment, the manifestation of dyslexia.

Dyslexia assessment in Arabic

Despite advancements in empirical studies of developmental dyslexia, progress on methods of dyslexia assessment have been hampered by ongoing debate concerning diverse issues such as the role and validity of IQ in the assessment process, labelling and definitions (Miles, 1994; Stanovich, 1991, 1992). With the emergence of cross-linguistic studies of dyslexia came the realisation that the manifestation of dyslexia is different in different languages (Goulandris, 2003; Smythe, Everatt & Salter, 2004). It follows that the assessment of dyslexia should consider specific linguistic features of the language spoken by the individual to be assessed. This paper argues for the need of culture-fair assessment and calls for considerations to be given when assessing monolingual Arabic-speaking individuals with dyslexia which would take into account the specific linguistic feature of the Arabic language.

Reading Acquisition, Developmental Dyslexia, and Skilled Reading Across Languages: A Psycholinguistic Grain Size Theory.

The development of reading depends on phonological awareness across all languages so far studied. Languages vary in the consistency with which phonology is represented in orthography. This results in developmental differences in the grain size of lexical representations and accompanying differences in developmental reading strategies and the manifestation of dyslexia across orthographies. Differences in lexical representations and reading across languages leave developmental "footprints" in the adult lexicon. The lexical organization and processing strategies that are characteristic of skilled reading in different orthographies are affected by different developmental constraints in different writing systems. The authors develop a novel theoretical framework to explain these cross-language data, which they label a psycholinguistic grain size theory of reading and its development.

Allophonic mode of speech perception in dyslexia

Perceptual discrimination between speech sounds belonging to different phoneme categories is better than that between sounds falling within the same category. This property, known as “categorical perception,” is weaker in children affected by dyslexia. Categorical perception develops from the predispositions of newborns for discriminating all potential phoneme categories in the world's languages. Predispositions that are not relevant for phoneme perception in the ambient language are usually deactivated during early childhood. However, the current study shows that dyslexic children maintain a higher sensitivity to phonemic distinctions irrelevant in their linguistic environment. This suggests that dyslexic children use an allophonic mode of speech perception that, although without straightforward consequences for oral communication, has obvious implications for the acquisition of alphabetic writing. Allophonic perception specifically affects the mapping between graphemes and phonemes, contrary to other manifestations of dyslexia, and may be a core deficit.

Phonological spelling errors among dyslexic children learning a transparent orthography: the case of Czech.

Substantial evidence from studies of English-speaking dyslexic children's spelling suggests that these individuals have a persistent impairment in representing the phonological structure and content of words in writing. In contrast, several studies of German dyslexic children (Landerl & Wimmer, 2000) suggest that, among learners of transparent orthographies, the above impairment is transient and resolves by the end of grade 2; instead dyslexic spelling is characterised by a persistent impairment in learning inconsistent spelling patterns. In order to determine whether phonological spelling difficulties are transient among dyslexic spellers of other transparent orthographies, we analysed phonological accuracy in the spellings of 43 dyslexic children, 43 age-matched control and 43 spelling-matched control children attending primary schools in Prague. Czech dyslexic children presented an interesting test case because Czech has a transparent orthography. Czech dyslexics as old as 11 years (grade 5) continued to produce high rates of phonologically inaccurate spellings relative to their age peers; thus their difficulties with phonological representation in spelling had not resolved. This pattern is consistent with findings from studies of English-speaking dyslexics, and it suggests that orthographic depth may impact less dramatically on the manifestation of dyslexia than has been proposed previously.

Universal dyslexia?

Estimates of the prevalence of dyslexia in different countries seem to reflect differences in orthographic complexity; dyslexia is more common in countries where the orthography (spelling) is complex (e.g. USA and Britain), compared with those where orthography is transparent (e.g. Italy). A recent study by Paulesu et al. has shown that, although the manifestation of dyslexia might differ depending on the precise orthography used, the core cognitive deficit and brain basis is universal 1 Paulesu E. et al. Dyslexia: cultural diversity and biological unity. Science. 2001; 291: 2165-2167 Crossref PubMed Scopus (824) Google Scholar . The study compared dyslexic and normal readers from countries with transparent (Italian) and complex (English and French) orthographies. Behaviourally, the dyslexics from each of the three countries showed a similar pattern of results, all performing poorly on subtests that required phonological short-term memory. Italian dyslexics did perform better than either the English or French dyslexics on reading tasks, but comparisons between dyslexic and normal readers from the same country revealed similarly marked differences irrespective of language.

Developmental Dyslexia: An Update on Genes, Brains, and Environments

The science of reading and developmental dyslexia has experienced spectacular advances during the last few years. Five aspects of this research are discussed in the article. (1) The holistic phenomenon of reading is complex. Many lower-level psychological processes (e.g., phonemic awareness, phonological decoding, ability to process stimuli rapidly and automatize this process, memory, ability to recognize words) contribute to a single act of reading. Conceptualizing the complex process of reading through its partly overlapping but partly independent components--which contribute to, but do not fully explain, the holistic process of reading--provides an excellent model for understanding complex hierarchies of higher mental functions. Those who master reading skills successfully and those who have difficulties doing so differ in a wide range of reading-related processes. The central deficit experienced by poor readers appears to be related to phonological processing (a complex hierarchy of functions related to processing phonemes), whereas characteristics of automatization processes seem to moderate the reading outcome for people whose phonological skills are weak. (2) There are new data addressing models of dyslexia in languages other than English. The most fascinating finding is that the model implicating phonological deficit as central to dyslexia, and the lack of ability to automatize as leading to troubled reading, appears to be universal, regardless of the specific language. However, there is an interaction effect between the characteristics of a particular language and the developmental model of dyslexia. In phonologically more difficult languages (e.g., English), the most pronounced weakness appears to occur in phonological processing, whereas in phonologically easier languages (e.g., German), the crucial role in the manifestation of dyslexia is played by the lack of the skills needed to achieve automatization. (3) There is abundant evidence that reading (i.e., any single act of reading as well as reading as a holistic process) is "cooked" by the brain. Although no unified brain map of reading has been developed, some specific areas of the brain have been implicated in different reading-related cognitive processes by different laboratories and on different samples. (4) Indisputable evidence has been accumulated suggesting the involvement of the genome in developmental dyslexia. As of now, specific regions of the genome have been identified as being intimately involved with a number of different reading-related processes. Today the field of developmental dyslexia is the only area of genetic studies of human abilities and disabilities in which linkages to the genome have been robustly replicated in independent laboratories. (5) Finally, evidence suggests that developmental dyslexia might be only one of the manifestations of a deep, underlying, anatomical syndrome. The comorbidity of developmental dyslexia with both internalizing and externalizing behavioral disturbances, as well as with other learning disabilities, underscores the need for wide-ranging cognitive and behavioral approaches in the remediation programs offered to dyslexic children.