Search results for "DEVELOPMENTAL DYSLEXIA"
showing 10 items of 34 documents
Genome-wide association scan identifies new variants associated with a cognitive predictor of dyslexia
2019
Developmental dyslexia (DD) is one of the most prevalent learning disorders, with high impact on school and psychosocial development and high comorbidity with conditions like attention-deficit hyperactivity disorder (ADHD), depression, and anxiety. DD is characterized by deficits in different cognitive skills, including word reading, spelling, rapid naming, and phonology. To investigate the genetic basis of DD, we conducted a genome-wide association study (GWAS) of these skills within one of the largest studies available, including nine cohorts of reading-impaired and typically developing children of European ancestry (N = 2562–3468). We observed a genome-wide significant effect (p < 1 × 10…
An extensive pattern of atypical neural speech-sound discrimination in newborns at risk of dyslexia.
2019
Objective: Identifying early signs of developmental dyslexia, associated with deficient speech-sound processing, is paramount to establish early interventions. We aimed to find early speech-sound processing deficiencies in dyslexia, expecting diminished and atypically lateralized event-related potentials (ERP) and mismatch responses (MMR) in newborns at dyslexia risk. Methods: ERPs were recorded to a pseudoword and its variants (vowel-duration, vowel-identity, and syllable-frequency changes) from 88 newborns at high or no familial risk. The response significance was tested, and group, laterality, and frontality effects were assessed with repeated-measures ANOVA. Results: An early positive a…
Does viotin activate violin more than viocin? On the use of visual cues during visual-word recognition.
2013
The vast majority of neural and computational models of visual-word recognition assume that lexical access is achieved via the activation of abstract letter identities. Thus, a word’s overall shape should play no role in this process. In the present lexical decision experiment, we compared word-like pseudowords like viotín (same shape as its base word: violín) vs. viocín (different shape) in mature (college-aged skilled readers), immature (normally reading children), and immature/impaired (young readers with developmental dyslexia) word-recognition systems. Results revealed similar response times (and error rates) to consistent-shape and inconsistent-shape pseudowords for both adult skille…
Developmental dyslexia: re-evaluation of the corpus callosum in male adults.
2000
Using a new method based upon the measurement of four angles, we analyzed the corpus callosum of 23 adult male dyslexics and 25 age-matched controls on MRI sagittal scans. Two out of the four angles measured showed significant differences between the groups that are consistent with previous findings concerning the size of the corpus callosum in dyslexics. In particular, posterior regions are concerned, displaying a lowered corpus callosum in dyslexics. These findings are discussed in relation to cortical parietal asymmetries and possible hormonal events, referring to the testosterone hypothesis, that could occur in utero or in the perinatal period in the dyslexic population.
Maternal stress and coping strategies in developmental Dyslexia: An Italian multicenter study
2017
BackgroundStudies about the impact of developmental dyslexia (DD) on parenting are scarce. Our investigation aimed to assess maternal stress levels and mothers’ copying styles in a population of dyslexic children.MethodsA total of 874 children (500 boys, 374 girls; mean age 8.32 ± 2.33 years) affected by DD was included in the study. A total of 1,421 typically developing children (789 boys, 632 girls; mean age 8.25 ± 3.19 years) were recruited from local schools of participating Italian Regions (Abruzzo, Calabria, Campania, Puglia, Umbria, Sicily) and used as control-children group. All mothers (of both DD and typically developing children) filled out an evaluation for parental stress (Pare…
Il ruolo dell'informazione contestuale e delle componenti sillabico-accentuali nella decodifica del testo scritto: un confronto tra dislessici evolut…
2010
L'esperimento qui presentato si propone di valutare l'importanza che assume, per un dislessico evolutivo rispetto ad un normolettore, la presenza di indizi che suggeriscano il significato del testo scritto (informazioni contestuali), nonché l'influenza di determinate caratteristiche sillabico-accentuali nelle prestazioni di lettura. Lo studio è stato condotto attraverso la somministrazione di frasi in ognuna delle quali è stata inserita una parola target secondo criteri relativi alla posizione (dislocazione a sinistra e dislocazione a destra) al fine di valutare l'influenza esercitata dall'informazione contestuale durante la decifrazione del testo. Le parole selezionate sono state accuratam…
[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…
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…