Dyslexic Children (dyslexic + child)

Distribution by Scientific Domains


Selected Abstracts


Low-level defective processing of non-verbal sounds in dyslexic children

DYSLEXIA, Issue 2 2009
Paulino Uclés
Abstract We compared processing of non-verbal auditory stimuli by dyslexic and non-dyslexic children using electrophysiological methods. The study included 39 children (17 with dyslexia plus 22 controls) assessed via frontal, central, parietal, and temporal electrodes. As an extension of previous P300 event-related potential studies, we analysed variations in the power values of 40-Hz oscillations (gamma-band oscillations involved in cognitive processing) during a specific time window in response to the auditory ,oddball' paradigm that entail target (random 2,kHz) and standard (frequent 1,kHz) stimuli. Dyslexic children differed significantly from controls (P<0.001) in the mean power of the wavelet-transformed 40-Hz oscillation in a time interval starting at 25 ms after stimulus onset up to 50 ms. This means defective processing of sounds. Within groups, standard and target tones elicited significantly different power values (P<0.001). Correlations of values between standard and target responses at each electrode position were not significant within either group, although dyslexics showed a lower correlation than controls. Significant differences in the mean power of these oscillations detected at very early stages of auditory processing in dyslexic children and the wide range of mean values reveal impairment in processing non-verbal sounds in dyslexia. Our results also support recent findings using behavioural and electrophysiological methods suggesting that dyslexia is a general auditory deficit instead of a speech-specific deficit. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Dichotic listening deficits in children with dyslexia

DYSLEXIA, Issue 1 2008
Deborah W. Moncrieff
Abstract Several auditory processing deficits have been reported in children with dyslexia. In order to assess for the presence of a binaural integration type of auditory processing deficit, dichotic listening tests with digits, words and consonant,vowel (CV) pairs were administered to two groups of right-handed 11-year-old children, one group diagnosed with developmental dyslexia and an age-matched control group. Dyslexic children performed more poorly than controls from their left ears when listening to digits and words and from their right ears when listening to CVs. Direction of ear advantage varied across individuals in both groups when tested with digits and CVs, but ear advantage was stable with words. Several factors that may have contributed to inconsistencies in direction of ear advantage are discussed. When the children were tested in a directed response mode, degree of ear advantage differed significantly between groups with both words and digits. More dyslexic than control children demonstrated clinically significant reductions in dichotic listening performance, but no uniform pattern of deficit emerged. Only the double correct score and the left ear score with CV pairs were predictive of word recognition performance in dyslexic children. Binaural integration deficits are present in some children with dyslexia. Auditory processing disorder assessment may help delineate factors that underlie or are associated with reading impairment in this population. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Rapid processing of letters, digits and symbols: what purely visual-attentional deficit in developmental dyslexia?

DEVELOPMENTAL SCIENCE, Issue 4 2010
Johannes C. Ziegler
Visual-attentional theories of dyslexia predict deficits for dyslexic children not only for the perception of letter strings but also for non-alphanumeric symbol strings. This prediction was tested in a two-alternative forced-choice paradigm with letters, digits, and symbols. Children with dyslexia showed significant deficits for letter and digit strings but not for symbol strings. This finding is difficult to explain for visual-attentional theories of dyslexia which postulate identical deficits for letters, digits and symbols. Moreover, dyslexics showed normal W-shaped serial position functions for letter and digit strings, which suggests that their deficit is not due to an abnormally small attentional window. Finally, the size of the deficit was identical for letters and digits, which suggests that poor letter perception is not just a consequence of the lack of reading. Together then, our results show that symbols that map onto phonological codes are impaired (i.e. letters and digits), whereas symbols that do not map onto phonological codes are not impaired. This dissociation suggests that impaired symbol-sound mapping rather than impaired visual-attentional processing is the key to understanding dyslexia. [source]


The role of sensorimotor impairments in dyslexia: a multiple case study of dyslexic children

DEVELOPMENTAL SCIENCE, Issue 3 2006
Sarah White
This study attempts to investigate the role of sensorimotor impairments in the reading disability that characterizes dyslexia. Twenty-three children with dyslexia were compared to 22 control children, matched for age and non-verbal intelligence, on tasks assessing literacy as well as phonological, visual, auditory and motor abilities. The dyslexic group as a whole were significantly impaired on phonological, but not sensorimotor, tasks. Analysis of individual data suggests that the most common impairments were on phonological and visual stress tasks and the vast majority of dyslexics had one of these two impairments. Furthermore, phonological skill was able to account for variation in literacy skill, to the exclusion of all sensorimotor factors, while neither auditory nor motor skill predicted any variance in phonological skill. Visual stress seems to account for a small proportion of dyslexics, independently of the commonly reported phonological deficit. However, there is little evidence for a causal role of auditory, motor or other visual impairments. [source]


Developmental dyslexia and explicit long-term memory

DYSLEXIA, Issue 3 2010
Deny Menghini
Abstract The reduced verbal long-term memory capacities often reported in dyslexics are generally interpreted as a consequence of their deficit in phonological coding. The present study was aimed at evaluating whether the learning deficit exhibited by dyslexics was restricted only to the verbal component of the long-term memory abilities or also involved visual-object and visual-spatial domain. A further goal of the present study was to investigate the predictive value of non-verbal long-term memory abilities with respect to word and non-word reading in dyslexic children. In accordance with these aims, performances of 60 dyslexic children were compared with that of 65 age-matched normal readers on verbal, visual-spatial and visual-object task. Results documented a generalized impairment of episodic long-term memory capacities in dyslexic children and the results did not vary as a function of children's age. Furthermore, in addition to verbal measures, also individual differences in non-verbal long-term memory tasks turn out to be good predictors of reading difficulties in dyslexics. Our findings indicate that the long-term memory deficit in dyslexia is not limited to the dysfunction of phonological components but also involves visual-object and visual-spatial aspect, thus suggesting that dyslexia is associated to multiple cognitive deficits. Copyright © 2010 John Wiley & Sons, Ltd. [source]


Visual spatial attention and speech segmentation are both impaired in preschoolers at familial risk for developmental dyslexia

DYSLEXIA, Issue 3 2010
Andrea Facoetti
Abstract Phonological skills are foundational of reading acquisition and impaired phonological processing is widely assumed to characterize dyslexic individuals. However, reading by phonological decoding also requires rapid selection of sublexical orthographic units through serial attentional orienting, and recent studies have shown that visual spatial attention is impaired in dyslexic children. Our study investigated these different neurocognitive dysfunctions, before reading acquisition, in a sample of preschoolers including children with (N=20) and without (N=67) familial risk for developmental dyslexia. Children were tested on phonological skills, rapid automatized naming, and visual spatial attention. At-risk children presented deficits in both visual spatial attention and syllabic segmentation at the group level. Moreover, the combination of visual spatial attention and syllabic segmentation scores was more reliable than either single measure for the identification of at-risk children. These findings suggest that both visuo-attentional and perisylvian-auditory dysfunctions might adversely affect reading acquisition, and may offer a new approach for early identification and remediation of developmental dyslexia. Copyright © 2010 John Wiley & Sons, Ltd. [source]


Computer-based training with ortho-phonological units in dyslexic children: new investigations

DYSLEXIA, Issue 3 2009
Jean Ecalle
Abstract This study aims to show that training using a computer game incorporating an audio-visual phoneme discrimination task with phonological units, presented simultaneously with orthographic units, might improve literacy skills. Two experiments were conducted, one in secondary schools with dyslexic children (Experiment 1) and the other in a speech-therapy clinic with individual case studies (Experiment 2). A classical pre-test, training, post-test design was used. The main findings indicated an improvement in reading scores after short intensive training (10,h) in Experiment 1 and progress in the reading and spelling scores obtained by the dyslexic children (training for 8,h) in Experiment 2. These results are discussed within the frameworks of both the speech-specific deficit theory of dyslexia and the connectionist models of reading development. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Low-level defective processing of non-verbal sounds in dyslexic children

DYSLEXIA, Issue 2 2009
Paulino Uclés
Abstract We compared processing of non-verbal auditory stimuli by dyslexic and non-dyslexic children using electrophysiological methods. The study included 39 children (17 with dyslexia plus 22 controls) assessed via frontal, central, parietal, and temporal electrodes. As an extension of previous P300 event-related potential studies, we analysed variations in the power values of 40-Hz oscillations (gamma-band oscillations involved in cognitive processing) during a specific time window in response to the auditory ,oddball' paradigm that entail target (random 2,kHz) and standard (frequent 1,kHz) stimuli. Dyslexic children differed significantly from controls (P<0.001) in the mean power of the wavelet-transformed 40-Hz oscillation in a time interval starting at 25 ms after stimulus onset up to 50 ms. This means defective processing of sounds. Within groups, standard and target tones elicited significantly different power values (P<0.001). Correlations of values between standard and target responses at each electrode position were not significant within either group, although dyslexics showed a lower correlation than controls. Significant differences in the mean power of these oscillations detected at very early stages of auditory processing in dyslexic children and the wide range of mean values reveal impairment in processing non-verbal sounds in dyslexia. Our results also support recent findings using behavioural and electrophysiological methods suggesting that dyslexia is a general auditory deficit instead of a speech-specific deficit. Copyright © 2008 John Wiley & Sons, Ltd. [source]


The sources and manifestations of stress amongst school-aged dyslexics, compared with sibling controls

DYSLEXIA, Issue 4 2008
Neil Alexander-Passe
Abstract All school children experience stress at some point in their school careers. This study investigates whether dyslexic children, by way of their educational and social difficulties, experience higher levels of stress at school. The School Situation Survey was used to investigate both the sources and manifestations of stress amongst dyslexic children and non-dyslexic sibling controls. Samples were broken down by gender, age and the size of families. Results suggest significant differences between the groups, with dyslexics in academic years 3,5 experiencing the highest stress levels, specifically in interactions with teachers, worries over academic examinations (SATs) and performance testing, causing emotional (fear, shyness and loneliness) and physiological (nausea, tremors or rapid heart beat) manifestations. Results also suggest that dyslexics in larger families (3,4 sibling families) experience greater stress in interactions with their peers, than those in smaller families (two sibling families),possibly from unfair sibling comparison. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Morphological constancy in spelling: a comparison of children with dyslexia and typically developing children

DYSLEXIA, Issue 3 2008
Derrick C. Bourassa
Abstract The spellings of many English words follow a principle of morphological constancy. For example, musician includes the c of music, even though the pronunciation of this letter changes. With other words, such as explanation and explain, the spellings of morphemes are not retained when affixes are added. We asked whether children with dyslexia use root morphemes to aid their spelling of morphologically complex words. If so, they should sometimes produce misspellings such as ,explaination' for explanation. Our results suggest that children with dyslexia adhere to the principle of morphological constancy to the same extent as typically developing younger children of the same spelling level. In this and other ways, the spellings of older dyslexic children are remarkably similar to those of typical younger children. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Fluency remediation in dyslexic children: does age make a difference?

DYSLEXIA, Issue 2 2008
Patrizio E. Tressoldi
Abstract This study tested the hypothesis whether older dyslexic children may obtain fewer gains on fluency and accuracy with respect to their younger peers after specific remediation. Changes in accuracy and fluency of a group of children with a diagnosis of dyslexia attending third and fourth grades were compared with those obtained by a group of children attending the sixth, seventh or eighth grade in two different treatments, one based on the Balance model (Bakker) and the second based on the automatization of syllable recognition (sublexical). Among all comparisons between the gains in accuracy and fluency obtained by the two groups, only the younger group in the sublexical treatment obtained a statistically significant gain with respect to their older peers' accuracy in reading words. These outcomes suggest that, at least for the chronological ages and types of treatments considered in this study, older children with dyslexia may obtain comparable gains to their younger peers, suggesting that ,it is never too late' to remediate reading fluency and accuracy. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Dichotic listening and school performance in dyslexia

DYSLEXIA, Issue 1 2008
Turid Helland
Abstract This study focused on the relationship between school performance and performance on a dichotic listening (DL) task in dyslexic children. Dyslexia is associated with impaired phonological processing, related to functions in the left temporal lobe. DL is a frequently used task to assess functions of the left temporal lobe. Due to the predominance of the contralateral neuronal pathways, a right ear advantage in the DL task reflects the superior processing capacity for the right ear stimulus in the left hemisphere (Kimura, 1963). Previous studies using DL in dyslexia are, however, inconclusive, and may reflect degree of severity of dyslexia. The aim of the present study was therefore to investigate lateralized processing in two sub-groups of dyslexia, differing in symptom severity. Two groups of dyslexic 12-year-old children and an age-matched control group were tested with a consonant,vowel DL task. The two dyslexia groups differed in severity through how they responded to training efforts being made in their schools, while otherwise being matched for age, IQ and diagnosis. The D1 (respondent group) group showed a DL performance pattern similar to the control group, i.e. a right ear advantage, while the D2 (non-respondent) group failed to show a right ear advantage on the DL task. The performance on the DL task by the two dyslexia groups may provide better insight as to the degree of reading and writing impairment in dyslexia. ,Cracking the code' and acquiring automatized literacy skills may seem harder for the D2 group children compared to the D1 children. Also, the present study points to the use of DL as a valid assessment tool in clinical work to improve differential diagnoses, particularly in relation to measures of school performance. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Dichotic listening deficits in children with dyslexia

DYSLEXIA, Issue 1 2008
Deborah W. Moncrieff
Abstract Several auditory processing deficits have been reported in children with dyslexia. In order to assess for the presence of a binaural integration type of auditory processing deficit, dichotic listening tests with digits, words and consonant,vowel (CV) pairs were administered to two groups of right-handed 11-year-old children, one group diagnosed with developmental dyslexia and an age-matched control group. Dyslexic children performed more poorly than controls from their left ears when listening to digits and words and from their right ears when listening to CVs. Direction of ear advantage varied across individuals in both groups when tested with digits and CVs, but ear advantage was stable with words. Several factors that may have contributed to inconsistencies in direction of ear advantage are discussed. When the children were tested in a directed response mode, degree of ear advantage differed significantly between groups with both words and digits. More dyslexic than control children demonstrated clinically significant reductions in dichotic listening performance, but no uniform pattern of deficit emerged. Only the double correct score and the left ear score with CV pairs were predictive of word recognition performance in dyslexic children. Binaural integration deficits are present in some children with dyslexia. Auditory processing disorder assessment may help delineate factors that underlie or are associated with reading impairment in this population. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Balancing and pointing tasks in dyslexic and control adults

DYSLEXIA, Issue 4 2006
Catherine J. Stoodley
Abstract Developmental dyslexia may affect as much as 15% of the population, but the aetiology of the disorder is still being debated. The cerebellar theory of dyslexia proposes that cerebellar dysfunction could lead to the myriad of symptoms seen in dyslexic individuals, both in literacy and non-literacy domains. The cerebellum is crucial to the fluent performance of motor skills. Previous studies have found that dyslexic children are worse than control children on certain motor and balancing tasks. Here the performance of 28 dyslexic compared to 26 control adults on rapid pointing and balancing measures, tasks which are thought to reflect cerebellar function, was investigated. There were no significant differences between the dyslexic and control participants on the balancing tasks or when the speed and accuracy of pointing were analysed separately. However, when the speed and accuracy of pointing were combined, the dyslexic participants showed poorer performance than the controls (p = 0.045). Furthermore, there were significant relationships between performance on the pointing task and literacy skills, and regression analysis showed that the error and speed of pointing contributed significantly to the variance in literacy skill. The implications for the role of the cerebellum and processing speed in dyslexia are discussed. Copyright © 2006 John Wiley & Sons, Ltd. [source]


Auditory and speech processing and reading development in Chinese school children: behavioural and ERP evidence

DYSLEXIA, Issue 4 2005
Xiangzhi Meng
Abstract By measuring behavioural performance and event-related potentials (ERPs) this study investigated the extent to which Chinese school children's reading development is influenced by their skills in auditory, speech, and temporal processing. In Experiment 1, 102 normal school children's performance in pure tone temporal order judgment, tone frequency discrimination, temporal interval discrimination and composite tone pattern discrimination was measured. Results showed that children's auditory processing skills correlated significantly with their reading fluency, phonological awareness, word naming latency, and the number of Chinese characters learned. Regression analyses found that tone temporal order judgment, temporal interval discrimination and composite tone pattern discrimination could account for 32% of variance in phonological awareness. Controlling for the effect of phonological awareness, auditory processing measures still contributed significantly to variance in reading fluency and character naming. In Experiment 2, mismatch negativities (MMN) in event-related brain potentials were recorded from dyslexic children and the matched normal children, while these children listened passively to Chinese syllables and auditory stimuli composed of pure tones. The two groups of children did not differ in MMN to stimuli deviated in pure tone frequency and Chinese lexical tones. But dyslexic children showed smaller MMN to stimuli deviated in initial consonants or vowels of Chinese syllables and to stimuli deviated in temporal information of composite tone patterns. These results suggested that Chinese dyslexic children have deficits in auditory temporal processing as well as in linguistic processing and that auditory and temporal processing is possibly as important to reading development of children in a logographic writing system as in an alphabetic system. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Working memory: Its role in dyslexia and other specific learning difficulties

DYSLEXIA, Issue 3 2004
Sharman Jeffries
Abstract This paper reports a study contrasting dyslexic children against a control group of children without special educational needs (SEN) and a group with varied SENs. Children's abilities were compared on tasks assessing phonological processing, visuo-spatial/motor coordination and executive/inhibitory functioning; being targeted for assessment based on theoretical proposals related to the working memory model. Primary and secondary school level children were tested: 21 assessed as dyslexic with no comorbid difficulties, 26 children assessed with difficulties including dyspraxia, emotional/behavioural problems and attention deficits, 40 children with no known education-related deficits were controls. Results indicated both SEN groups performed worse than controls on working memory phonological loop measures. However, SEN groups could only be differentiated on phonological awareness measures: the dyslexics showing lower scores. Dyslexics performed as well as controls on working memory visuo-spatial scratch pad measures and one of two additional visual,motor coordination tasks, whereas the performance of the other SEN children was lowest on the majority of these measures. Central executive and interference measures engendered mixed performances, both SEN groups showing evidence of deficits in one or more of these areas of functioning, although, of the two SEN groups, the dyslexics seem to have performed the worse when digit name processing was required. Copyright © 2004 John Wiley & Sons, Ltd. [source]


Reading intervention: A ,conventional' and successful approach to helping dyslexic children acquire literacy

DYSLEXIA, Issue 3 2003
Peter J. Hatcher
Abstract The effectiveness of the ,conventional' approach to helping children with dyslexia to acquire literacy has been questioned by Reynolds et al. (Dyslexia 2003). Data are presented in this reply to support the effectiveness of Reading Intervention, a conventional approach to teaching reading delayed children. Copyright © 2003 John Wiley & Sons, Ltd. [source]


Dyslexia and music: measuring musical timing skills

DYSLEXIA, Issue 1 2003
Katie Overy
Abstract Over the last few decades, a growing amount of research has suggested that dyslexics have particular difficulties with skills involving accurate or rapid timing, including musical timing skills. It has been hypothesised that music training may be able to remediate such timing difficulties, and have a positive effect on fundamental perceptual skills that are important in the development of language and literacy skills (Overy, 2000). In order to explore this hypothesis further, the nature and extent of dyslexics' musical difficulties need to be examined in more detail. In the present study, a collection of musical aptitude tests (MATs) were designed specifically for dyslexic children, in order to distinguish between a variety of musical skills and sub-skills. 15 dyslexic children (age 7,11, mean age 9.0) and 11 control children (age 7,10, mean age 8.9) were tested on the MATs, and their scores were compared. Results showed that the dyslexic group scored higher than the control group on 3 tests of pitch skills (possibly attributable to slightly greater musical experience), but lower than the control group on 7 out of 9 tests of timing skills. Particular difficulties were noted on one of the tests involving rapid temporal processing, in which a subgroup of 5 of the dyslexic children (33%) (mean age 8.4) was found to account for all the significant error. Also, an interesting correlation was found between spelling ability and the skill of tapping out the rhythm of a song, which both involve the skill of syllable segmentation. These results support suggestions that timing is a difficulty area for dyslexic children, and suggest that rhythm skills and rapid skills may need particular attention in any form of musical training with dyslexics. Copyright © 2003 John Wiley & Sons, Ltd. [source]


A pictographic method for teaching spelling to Greek dyslexic children

DYSLEXIA, Issue 2 2002
Th.D. Mavrommati
Abstract In the Greek orthography every letter consistently represents the same sound, but the same sound can be represented by different letters or pairs of letters. This makes spelling more difficult than reading. Two methods of teaching spelling to Greek dyslexic children are compared. The first involved pictograms (specially drawn pictures) for use when alternative spellings are possible. This is referred to as the ,PICTO' method. The second was in effect a combination of two traditional methods: the first involved the teaching of letter-sound correspondences in a multisensory way; the second involved the use of concepts derived from linguistics, the children being taught the derivations of words and shown how the same root morphemes, derivative morphemes, etc., were cosistently represented by the same spelling pattern. This combination of methods is referred to as ,TRAD', signifying ,traditional'. There were 72 subjects in the study, aged between 9 and 11 years. Four different teachers, each using both PICTO and TRAD, took part in the teaching sessions. The PICTO method proved considerably more effective; and possible reasons are suggested as to why this might be so. Copyright © 2002 John Wiley & Sons, Ltd. [source]


Egocentric mental rotation in Hungarian dyslexic children

DYSLEXIA, Issue 1 2001
Kázmér Karádi
Abstract A mental rotation task was given to 27 dyslexic children (mean age 9 years, 2 months) and to 28 non-dyslexic children (mean age 8 years, 8 months). Pictures of right and left hands were shown at angles of 0, 50, 90 and 180 degrees, and the subjects were required to indicate whether what was shown was a right hand or a left hand. It was found that, in this task, the dyslexics did not show the normal pattern of response times at different angles, and also, that they made more errors than the controls. It is argued that this result is compatible with hypothesis that, in typical cases of dyslexia, there is a malfunctioning in the posterior parietal area. Copyright © 2001 John Wiley & Sons, Ltd. [source]


From language to reading and dyslexia,

DYSLEXIA, Issue 1 2001
Margaret J. Snowling
Abstract This paper reviews evidence in support of the phonological deficit hypothesis of dyslexia. Findings from two experimental studies suggest that the phonological deficits of dyslexic children and adults cannot be explained in terms of impairments in low-level auditory mechanisms, but reflect higher-level language weaknesses. A study of individual differences in the pattern of reading skills in dyslexic children rejects the notion of ,sub-types'. Instead, the findings suggest that the variation seen in reading processes can be accounted for by differences in the severity of individual children's phonological deficits, modified by compensatory factors including visual memory, perceptual speed and print exposure. Children at genetic risk who go on to be dyslexic come to the task of reading with poorly specified phonological representations in the context of a more general delay in oral language development. Their prognosis (and that of their unaffected siblings) depends upon the balance of strengths and difficulties they show, with better language skills being a protective factor. Taken together, these findings suggest that current challenges to the phonological deficit theory can be met. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Complex CAM programme not effective in dyslexic children

FOCUS ON ALTERNATIVE AND COMPLEMENTARY THERAPIES AN EVIDENCE-BASED APPROACH, Issue 3 2007
Article first published online: 14 JUN 2010
[source]


Genetics and Neuroscience in Dyslexia: Perspectives for Education and Remediation

MIND, BRAIN, AND EDUCATION, Issue 4 2007
Gerd Schulte-Körne
ABSTRACT , Our understanding of the causes of a developmental disorder like dyslexia has received recent input from both neuroscience and genetics. The discovery of 4 candidate genes for dyslexia and the identification of neuronal networks engaged when children read and spell are the basis for introducing this knowledge into education. However, the input from educational practitioners as well as empirical knowledge from research on learning also contribute significantly to our understanding of how children acquire the basic skills for learning to read and spell. It is imperative to merge the knowledge acquired from research in the fields of neuroscience, genetics, and empirical education, as well as to understand how the learning brain and instruction interact. Doing so can be seen as a major step in attaining an optimal approach for teaching, reading, and spelling and for finding the best suited and most effective treatment concepts for dyslexic children and adolescents. [source]