Abnormality of mismatch negativity in response to tone omission in dyslexic adults

Evidence of abnormalities in the perception of rapidly presented sounds in dyslexia has been interpreted as evidence of a prolonged time window within which sounds can influence the perception of temporally surrounding sounds. We recorded the magnetic mismatch negativity (MMNm) to infrequent tone omissions in a group of six dyslexic adults and six IQ and age-matched controls. An MMNm is only elicited in response to a complete stimulus omission when successive inputs fall within the temporal window of integration (stimulus onset asynchrony (SOA) ∼160 ms). No MMNm responses were recorded in either experimental group when stimuli were presented at SOAs falling just outside the temporal window of integration (SOA = 175 ms). However, while presentation rates of 100 ms resulted in MMNm responses for all control participants, the same stimulus omissions elicited an MMNm response in only one of the six dyslexic participants. These results cannot support the hypothesis of a prolonged time window of integration, but rather indicate auditory grouping deficits in the dyslexic population. © 2006 Elsevier B.V. All rights reserved.

The handedness-associated PCSK6 locus spans an intronic promoter regulating novel transcripts

We recently reported the association of the PCSK6 gene with handedness through a quantitative genome-wide association study (GWAS; P < 0.5 × 10(-8)) for a relative hand skill measure in individuals with dyslexia. PCSK6 activates Nodal, a morphogen involved in regulating left-right body axis determination. Therefore, the GWAS data suggest that the biology underlying the patterning of structural asymmetries may also contribute to behavioural laterality, e.g. handedness. The association is further supported by an independent study reporting a variable number tandem repeat (VNTR) within the same PCSK6 locus to be associated with degree of handedness in a general population cohort. Here, we have conducted a functional analysis of the PCSK6 locus combining further genetic analysis, in silico predictions and molecular assays. We have shown that the previous GWAS signal was not tagging a VNTR effect, suggesting that the two markers have independent effects. We demonstrated experimentally that one of the top GWAS-associated markers, rs11855145, directly alters the binding site for a nuclear factor. Furthermore, we have shown that the predicted regulatory region adjacent to rs11855415 acts as a bidirectional promoter controlling the expression of novel RNA transcripts. These include both an antisense long non-coding RNA (lncRNA) and a short PCSK6 isoform predicted to be coding. This is the first molecular characterization of a handedness-associated locus that supports the role of common variants in non-coding sequences in influencing complex phenotypes through gene expression regulation.

A case of bilateral perisylvian syndrome with reading disability

Bilateral Perisylvian Syndrome (BPS) often presents with epilepsy and significant behavioral impairments that can include mental retardation, dysarthria, delayed speech development, and delayed fine motor development (Graff-Radford et al., 1986 and Kuzniecky et al., 1993). While a small subset of BPS cases have been described as having relatively isolated language delays (Leventer et al., 2010), BPS is not expected in children with dyslexia. As part of a Medical University of South Carolina, IRB approved multi-site study involving retrospective and de-identified dyslexia data, we unexpectedly identified a 14.05 year old male with evidence of BPS whose father had been diagnosed with dyslexia and dysgraphia. This child had been recruited for a neuroimaging study on dyslexia from a school specializing in educating children with dyslexia. The T1-weighted MRI scan from this child demonstrated a highly unusual perisylvian sulcal/gyral patterning that is a defining feature of BPS (Fig. 1). BPS cases exhibit bilateral dysgenesis of the Sylvian fissure and surrounding gyri, which appears to occur because of a limited or absent arcuate fasciculus (Kilinc, Ekinci, Demirkol, & Agan, 2015). This BPS case also had a relatively enlarged atrium of the lateral ventricle that is consistent with the BPS anatomical presentation and reduction of parietal white matter (Graff-Radford et al., 1986, Kilinc et al., 2015 and Toldo et al., 2011).

An Analysis of Individual Differences for a Computer Self-Regulated Reading Comprehension Task

Recent developments in brain imagery have made it possible to explore links between brain functions and psychological phenomena, opening a window between mind, brain and behavior. However, behavior cannot be understood solely by looking at the brain alone; the roles of the context, task, and practice are potent forces in shaping behavior. According to these ideas, we present a work experience to reflect on: 1) the variations of how people learn, 2) the learning potential of students with learning disabilities, and 3) computers as a tool to learn and to analyze student’s reading comprehension processes. In this vein, we present and discuss an example of how different types of readers (average, dyslexia, and hemispherectomy) undertake a computer self-regulated reading comprehension task. This is not an experimental research study and results cannot be generalized. Theoretical and educational implications are discussed in line with the proposed aims.

Further evidence for a parent-of-origin effect at the NOP9 locus on language-related phenotypes

Background - Specific language impairment (SLI) is a common neurodevelopmental disorder, observed in 5–10 % of children. Family and twin studies suggest a strong genetic component, but relatively few candidate genes have been reported to date. A recent genome-wide association study (GWAS) described the first statistically significant association specifically for a SLI cohort between a missense variant (rs4280164) in the NOP9 gene and language-related phenotypes under a parent-of-origin model. Replications of these findings are particularly challenging because the availability of parental DNA is required. Methods - We used two independent family-based cohorts characterised with reading- and language-related traits: a longitudinal cohort (n = 106 informative families) including children with language and reading difficulties and a nuclear family cohort (n = 264 families) selected for dyslexia. Results - We observed association with language-related measures when modelling for parent-of-origin effects at the NOP9 locus in both cohorts: minimum P = 0.001 for phonological awareness with a paternal effect in the first cohort and minimum P = 0.0004 for irregular word reading with a maternal effect in the second cohort. Allelic and parental trends were not consistent when compared to the original study. Conclusions - A parent-of-origin effect at this locus was detected in both cohorts, albeit with different trends. These findings contribute in interpreting the original GWAS report and support further investigations of the NOP9 locus and its role in language-related traits. A systematic evaluation of parent-of-origin effects in genetic association studies has the potential to reveal novel mechanisms underlying complex traits.

Papel do PCT na diferenciação pedagógica e curricular de alunos com DEA/Dislexia

O presente estudo partiu de preocupações da prática relacionadas com o papel do PCT no desenvolvimento pedagógico e curricular sobretudo de alunos com dislexia. No sentido de se responder à pergunta de partida: “de que forma a diferenciação pedagógica e curricular dos alunos com DEA/Dislexia, é contemplada no PCT?” elaborou-se um quadro teórico onde se começou por discutir o papel da escola recorrendo inclusivamente à sua perspectivação histórica. Esta permitiu perceber a escola actual nomeadamente nas tensões entre os processos de massificação escolar conducentes a uma hegemonia do currículo e os processos de flexibilização curricular. O nosso interesse principal situou-se nestes últimos pela sua importância para a diferenciação curricular e pedagógica na sala de aula necessária para os alunos com dislexia. A formação dos professores desempenha neste contexto uma grande relevância, pelo que lhe atribuímos elevada importância. Utilizando como instrumentos de recolha inquéritos por questionário articulados com a análise dos PCTs inquirimos uma amostra de vinte e oito professores de um agrupamento de escolas do distrito de Santarém sobre a sua percepção face à dislexia e à importância dada à utilização do PCT. Os dados recolhidos e tratados permitiram verificar que nem os PCT são encarados como um instrumento de diferenciação curricular e pedagógica, resultando em algumas contradições entre o que se diz fazer e o que se faz efectivamente, nem a DEA/Dislexia é encarada como um problema, que apesar de real não se vê contemplada, de forma explícita nos PCT. Desta forma, consideramos que o estudo realizado (embora limitado no tempo e espaço) permite desvendar algumas das suas representações mostrando uma forte relação entre a ausência de formação e o impacto que esta lacuna tem nas práticas docentes.

Stellungnahme zu: Diagnostik und Behandlung von Kindern und Jugendlichen mit Lese- und/oder Rechtschreibstörung. Evidenz- und konsensbasierte Leitlinie

Die Leitlinie zur Diagnostik und Behandlung von Kindern mit Lese- und/ oder Rechtschreibstörung hat sich zwei Ziele gesetzt: „klare, empirisch fundierte Handlungsanweisungen für eine eindeutige und objektive Diagnostik der Lese- und/oder Rechtschreibstörung bereitzustellen und über die Wirksamkeit von Fördermaßnahmen zu informieren“ ... Ferner wird eine Konsensbasierung angestrebt, wobei allerdings zu bemerken ist, dass Verbände und Organisationen, die sich bekanntermaßen kritisch mit dem medizinischen Ansatz von Lese-Rechtschreibstörung auseinandersetzen, nicht an der Leitlinie mitgewirkt haben … Im Folgenden [erörtert die Autorin] aus der Sicht einer langjährigen Legasthenieforscherin und Grundschulpädagogin die Frage …, ob es gelungen ist, diese Zielsetzungen zu realisieren. Da – in der Terminologie der Leitlinie - auch die Schule zum „Versorgungsbereich“ gehört, in dem die hier empfohlene Diagnostik und Förderung eingesetzt werden soll, und zur „Anwenderzielgruppe“ auch Lehrkräfte, Sonderpädagog/inn/en und Heilpädagog/inn/en gehören, ist ein pädagogischer Blick auf die Leitlinie, an deren Entstehung überwiegend medizinische Fachleute beteiligt waren, wichtig und notwendig. (DIPF/Orig.)

Behavioral and neuroimaging research of reading: A case of Japanese

Behavioral studies showed that AS, an English-Japanese bilingual was a skilled reader in Japanese but was a phonological dyslexic in English. This behavioral dissociation was accounted for by the Hypothesis of Transparency and Granularity postulated by Wydell & Butterworth. However, a neuroimaging study using MEG (magnetoencephalography) revealed that AS has the same functional deficit in the left superior temporal gyrus (STG). This paper therefore offers an answer to this intriguing discrepancy between the behavioral dissociation and the neural unity in AS by reviewing existing behavioral and neuroimaging studies in alphabetic languages such as English, Finnish, French, and Italian, and nonalphabetic languages such as Japanese and Chinese.

Estabelecimento do mecanismo de supressão da invariância percetiva em crianças disléxicas: um estudo experimental com crianças do 1º ciclo do ensino básico

O presente estudo investigou se as dificuldades das crianças disléxicas na leitura estão relacionadas com défices no processamento da orientação de estímulos visuais. A amostra foi constituída por 12 crianças disléxicas no final do 4.º ano, e dois grupos de controlo: 12 crianças de final de 4.º ano emparelhadas em idade cronológica e 11 crianças de final de 2.º ano emparelhadas em idade de leitura. As crianças realizaram duas tarefas experimentais igual-diferente onde tinham que assinalar letras ou figuras que tivessem a mesma forma, na tarefa de orientação independente, ou a mesma forma e a mesma orientação, na tarefa de orientação dependente. As crianças disléxicas tiveram dificuldade em identificar como diferentes, pares de letras ou figuras espelhadas, tal como as crianças mais novas, o que não aconteceu com as crianças com a mesma idade cronológica. Os resultados sugerem que as crianças disléxicas têm dificuldade com a orientação quando é necessário esta ser tida em conta; Establishment of the suppression of perceptual invariance mechanism in dyslexic children: an experimental study with children of the 1st cycle of Basic Education Abstract: This study investigated if the difficulties of dyslexic children in reading are related to deficits in processing the orientation of visual stimuli. The sample included 12 dyslexic children at the end of the 4th grade, and two control groups: 12 children also at the end of the 4th grade, matched on chronological age, and 11 children at the end of 2nd grade matched on reading age. The children performed two same-different experimental tasks which required them to identify the letters or figures that had the same shape - independent orientation task - or the same shape and the same orientation - dependent orientation task. Dyslexic children performed worse than chronological controls and similar to younger children when they were required to explicitly identify as different pairs of mirrored letters or figures. The present data suggests that dyslexic children may have some deficit in processing the orientation of visual stimuli.

À quelles causes les élèves inscrits au cours d’été en histoire et éducation à la citoyenneté de quatrième secondaire attribuent-ils leur échec à l’épreuve unique ministérielle?

Méthodologie: Recherche qualitative de type phénoménologique, ethnographique (Fortin, Côté, & Filion, 2006) ; Interactionnisme symbolique (Poisson, 1992)