Search results for " Dyslexia"
showing 10 items of 60 documents
[Psychocognitive and psychiatric disorders associated with developmental dyslexia: A clinical and scientific issue].
2008
Abstract INTRODUCTION: Dyslexia is a complex neurodevelopemental disorder that affects 5 to 10% of school-age children. This condition consists in a specific learning disability with a neurological origin. These learning difficulties are unexpected in relation to other cognitive abilities and the provision of efficient classroom instruction. A range of neurobiological investigations suggests that disruption of the parieto-temporo-occipital systems underlies a failure of skilled reading to develop. The observation that dyslexia is both a familial and heritable problem was made early on and was confirmed by twin studies. They also suggested that both genetic and environmental factors are invo…
Neural correlates of morphological processing and its development from pre-school to the first grade in children with and without familial risk for d…
2022
Previous studies have shown that the development of morphological awareness and reading skills are interlinked. However, most have focused on phonological awareness as a risk factor for dyslexia, although there is considerable diversity in the underlying causes of this reading difficulty. Specifically, the relationship between phonology, derivational morphology, and dyslexia in the Finnish language remains unclear. In the present study, we used magnetoencephalography (MEG) to measure the brain responses to correctly and incorrectly derived Finnish nouns in 34 first grade Finnish children (21 typically developing and 13 with familial risk for dyslexia). In addition, we compared longitudinall…
Psychophysiology of developmental dyslexia: a review of findings including studies of children at risk for dyslexia
2005
Abstract Brain imaging results illustrative of the search for neuronal markers of dyslexia are reviewed. Event-related potentials (ERPs) are shown to be effective indices of auditory processes involved in speech perception and thus, apparently also helpful in uncovering the neuronal basis of language problems associated with difficulties in reading. Results from the authors' laboratory show that, even at a very early age, brain responses (ERPs) to speech sounds can differentiate children with and without risk for dyslexia and also show reliable predictive correlations to later language development and reading acquisition. The review also covers dyslexia research in which other brain imaging…
Measuring orthographic transparency and morphological-syllabic complexity in alphabetic orthographies
2017
This narrative review discusses quantitative indices measuring differences between alphabetic languages that are related to the process of word recognition. The specific orthography that a child is acquiring has been identified as a central element influencing reading acquisition and dyslexia. However, the development of reliable metrics to measure differences between language scripts hasn’t received much attention so far. This paper therefore reviews metrics proposed in the literature for quantifying orthographic transparency, syllabic complexity, and morphological complexity of alphabetic languages. The review included searches of Web of Science, PubMed, PsychInfo, Google Scholar, and var…
The role of letters and syllables in typical and dysfluent reading in a transparent orthography
2012
The role of letters and syllables in typical and dysfluent 2nd grade reading in Finnish, a transparent orthography, was assessed by lexical decision and naming tasks. Typical readers did not show reliable word length effects in lexical decision, suggesting establishment of parallel letter processing. However, there were small effects of word syllable structure in both tasks suggesting the presence of some sublexical processing also. Dysfluent readers showed large word length effects in both tasks indicating decoding at the letterphoneme level. When lexical access was required in a lexical decision task, dyslexics additionally chunked the letters into syllables. Response duration measure rev…
Dual-stage and dual-deficit? Word recognition processes during text reading across the reading fluency continuum
2021
AbstractCentral questions in the study of visual word recognition and developmental dyslexia are whether early lexical activation precedes and supports decoding (a dual-stage view) or not (dual-route view), and the locus of deficits in dysfluent reading. The dual-route view predicts early word frequency and length interaction, whereas the dual-stage view predicts word frequency effect to precede the interaction effect. These predictions were tested on eye movements data collected from (n = 152) children aged 9–10 among whom reading dysfluency was overrepresented. In line with the dual-stage view, the results revealed an early word frequency effect in first fixation duration followed by robu…
Grey matter reduction in the occipitotemporal cortex in Spanish children with dyslexia: A voxel-based morphometry study
2020
Abstract Structural and functional neuroimaging studies have reported brain alterations in occipitotemporal, temporoparietal, and left frontal areas in dyslexic patients. These areas have been linked to reading skill impairments, due to their involvement in word recognition and processing. However, most of the patients in these studies were speakers of languages with a deep orthography. In this study, we used voxel-based morphometry (VBM) to investigate brain differences in grey matter volume associated with a transparent language in a sample of 25 native Spanish participants (13 dyslexic and 12 non-dyslexic children). Results revealed a volume reduction in the left occipitotemporal cortex …
Dyslexia—Early Identification and Prevention: Highlights from the Jyväskylä Longitudinal Study of Dyslexia
2015
Over two decades of Finnish research, monitoring children born with risk for dyslexia has been carried out in the Jyvaskyla Longitudinal Study of Dyslexia (JLD). Two hundred children, half at risk, have been assessed from birth to puberty on hundreds of measures. The aims were to identify measures of prediction of later reading difficulty and to instigate appropriate and earliest diagnosis and intervention. We can identify at-risk children from newborn electroencephalographic brain recordings (Guttorm et al., J Neural Transm 110:1059–1074, 2003). Predictors are also apparent from late-talking infants who have familial background of dyslexia (Lyytinen and Lyytinen, Appl Psycolinguistics 25:3…
Reading development subtypes and their early characteristics.
2007
The present findings are drawn from the Jyväskylä Longitudinal Study of Dyslexia (JLD), in which approximately 100 children with familial risk of dyslexia and 100 control children have been followed from birth. In this paper we report data on the reading development of the JLD children and their classmates, a total of 1,750 children from four measurement points during the first two school years. In the total sample, we examined whether heterogeneous developmental paths can be identified based on profiles of word recognition and reading comprehension. Secondly, we studied what kind of early language and literacy skill profiles and reading experiences characterize the children with differing …
Behavioral and Brain Measures of Morphological Processing in Children With and Without Familial Risk for Dyslexia From Pre-school to First Grade
2021
School-age reading skills are associated with and predicted by preschool-age cognitive risk factors for dyslexia, such as deficits in phonological awareness, rapid automatized naming, letter knowledge, and verbal short-term memory. In addition, evidence exists that problems in morphological information processing could be considered a risk factor for dyslexia. In the present study, 27 children at pre-school age and the same 27 children at first grade age performed a morphological awareness task while their brain responses were measured with magnetoencephalography. Our aim was to examine how derivational morphology in Finnish language, and concomitant accuracy and reaction times are associat…