Disentangling the Grammar of 3- to 6-Year-Old Dutch Children With a Developmental Language Disorder.

PURPOSE: Children with a developmental language disorder (DLD) are often delayed in their grammatical development. This is suggested to be the most important characteristic and clinical marker of DLD. However, it is unknown if this assumption is valid for young children, in the earliest stages of grammatical development. For this reason, this study investigates the complexity, diversity, and accuracy of the grammatical repertoires of 3- to 6-year-old Dutch children with DLD, in comparison to that of typically developing (TD) children matched on grammatical level. METHOD: Language samples of 59 children (29 children with DLD and 30 TD children) were analyzed using multiple measures of grammatical complexity, diversity, and accuracy. The TD children and children with DLD were language-matched on their grammatical development using the levels of the Dutch version of the Language Assessment, Remediation, and Screening Procedure, the Taal Analyse Remediëring en Screening Procedure (TARSP; Schlichting, 2017). Thus, the children with DLD were significantly older than the TD children (respectively DLD age range: 2;7-5;4 [years;months], M age = 4;1; and TD age range: 2;0-3;9, M age = 2;9). RESULTS: The results show that children with DLD are comparable to language-matched TD children in their grammatical accuracy and diversity, but that they produce less complex utterances. CONCLUSIONS: The results indicate that children with DLD lag behind in their grammatical complexity as compared to language-matched TD children. The results also suggest that grammatical TARSP level is not sufficiently informative for selecting treatment goals. Instead, the results underline the importance of conducting language sample analyses, with special reference to the complexity of the utterances of a child with DLD.

Predictors for grade 6 reading in children at familial risk of dyslexia.

The present study investigates whether grade 6 reading outcomes, reading fluency, and reading comprehension can be predicted by grade 3 reading fluency, familial risk of dyslexia (FR), and grade 3 reading related skills: rapid automatized naming (RAN), phonological awareness (PA), and vocabulary. In a sample of 150 children, of whom 83 had a parent with dyslexia, correlation and regression analyses were performed. FR, measured on a continuous scale, was by itself related to all outcomes. However, FR did not explain any variance on top of grade 3 reading fluency. Grade 3 reading fluency strongly predicted grade 6 reading fluency and was also related to reading comprehension. RAN improved the prediction of grade 6 reading fluency, though the additional explained variance was small. Vocabulary and PA fully explained the variance that grade 3 reading fluency explained in grade 6 reading comprehension. Vocabulary explained a substantial amount of variance in grade 6 reading comprehension making it an interesting clinical target. As we used continuous measures of reading fluency and FR, our findings are not biased by distinct diagnostic criteria.

L1 and L2 reading skills in Dutch adolescents with a familial risk of dyslexia.

BACKGROUND: The present study investigated differences in reading and spelling outcomes in Dutch and English as a second language (ESL) in adolescents with a high familial risk of dyslexia, of whom some have developed dyslexia (HRDys) while others have not (HRnonDys), in comparison to a low familial risk control group without dyslexia (LRnonDys). This allowed us to investigate the persistence of dyslexia in the first language (L1) and the effect of dyslexia on the second language (L2), which has, in this case, a lower orthographic transparency. Furthermore, the inclusion of the HRnonDys group allowed us to investigate the continuity of the familial risk of dyslexia, as previous studies observed that the HRnonDys group often scores in between the HRDys and LRnonDys group, and whether these readers without reading deficits in Dutch, have more reading difficulties in ESL. METHODS: The data of three groups of adolescents were analyzed; 27 LRnonDys, 25 HRdys 25 HRnonDys. The mean age was 14;1 years; months, and 37 were male. All were native speakers of Dutch, attended regular secondary education (grade 7-10), and were non-native speakers of English. Using MANOVA the groups were compared on Dutch and English word reading fluency (WRF), spelling and vocabulary, Dutch pseudoword and loanword reading fluency, phonological awareness (PA), rapid automatized naming (RAN), and verbal short term and working memory. A repeated measures ANOVA was used to compare English and Dutch WRF, spelling and vocabulary directly within the three groups. RESULTS: The analyses revealed that the HRDys group had a deficit in both reading and spelling in Dutch and ESL. They also performed poorer than the LRnonDys group on all other measures. Effect sizes were especially large for pseudoword reading and the reaction times during the PA task. The HRnonDys group scored generally poorer than the LRnonDys group but this difference was only significant for Dutch pseudoword reading, PA reaction times and verbal short term memory. In general the HRDys and HRnonDys group scored similar in Dutch and English, except for English WRF where the HRDys group scored slightly better than expected based on their Dutch WRF. DISCUSSION: There was a high persistence of dyslexia. Adolescents with dyslexia had large impairments in reading and spelling, and reading related measures, both in Dutch and ESL. Despite high inter-individual differences, an overall three-step pattern was observed. Adolescents in the HRnonDys group scored in between the HRDys and LRnonDys group, supporting the polygenetic origin of dyslexia and the continuity of the familial risk of dyslexia. The lower orthographic transparency did not have a negative effect on L2 reading, spelling and vocabulary, both in the HRnonDys and HRDys group. The latter group performed slightly better than expected in L2, which may be a result of the massive exposure to English and high motivation to use English by adolescents.

Improvements in reading accuracy as a result of increased interletter spacing are not specific to children with dyslexia.

Recently, increased interletter spacing (LS) has been studied as a way to enhance reading fluency. It is suggested that increased LS improves reading performance, especially in poor readers. Theoretically, these findings are well substantiated as a result of diminished crowding effects. Empirically, however, findings on LS are inconclusive. In two experiments, we examined whether effects of increased LS are specific to children with dyslexia and whether increased LS affects word or sentence processing. In the first experiment, 30 children with dyslexia and 30 controls (mean age=9years 11months) read sentences in standard and increased LS conditions. In the second experiment, these sentences were read by an unselected sample of 189 readers (mean age=9years 3months) in either a sentence or word-by-word reading condition. The first experiment showed that increased LS affected children with dyslexia and controls in similar ways. Participants made fewer errors in the increased LS condition than in the standard LS condition. Reading rates were not affected. There were no indications that the effect of LS was related to reading ability, not even for a subgroup of readers. Findings of the second experiment were similar. Increased LS resulted in fewer errors, not faster reading rates. This was found only when complete sentences were presented, not when sentences were read word by word. Three main conclusions can be drawn. First, increased LS appears to affect reading accuracy only. Second, the findings do not support claims that increased LS specifically affects poor readers. And third, the effect of LS seems to occur at the interword level. Theoretical and practical implications of these findings are discussed.

The Role of Categorical Speech Perception and Phonological Processing in Familial Risk Children With and Without Dyslexia.

Purpose: This study assessed whether a categorical speech perception (CP) deficit is associated with dyslexia or familial risk for dyslexia, by exploring a possible cascading relation from speech perception to phonology to reading and by identifying whether speech perception distinguishes familial risk (FR) children with dyslexia (FRD) from those without dyslexia (FRND). Method: Data were collected from 9-year-old FRD (n = 37) and FRND (n = 41) children and age-matched controls (n = 49) on CP identification and discrimination and on the phonological processing measures rapid automatized naming, phoneme awareness, and nonword repetition. Results: The FRD group performed more poorly on CP than the FRND and control groups. Findings on phonological processing align with the literature in that (a) phonological processing related to reading and (b) the FRD group showed the lowest phonological processing outcomes. Furthermore, CP correlated weakly with reading, but this relationship was fully mediated by rapid automatized naming. Conclusion: Although CP phonological skills are related to dyslexia, there was no strong evidence for a cascade from CP to phonology to reading. Deficits in CP at the behavioral level are not directly associated with dyslexia.

Dichotic listening as an index of lateralization of speech perception in familial risk children with and without dyslexia.

Atypical language lateralization has been marked as one of the factors that may contribute to the development of dyslexia. Indeed, atypical lateralization of linguistic functions such as speech processing in dyslexia has been demonstrated using neuroimaging studies, but also using the behavioral dichotic listening (DL) method. However, so far, DL results have been mixed. The current study assesses lateralization of speech processing by using DL in a sample of children at familial risk (FR) for dyslexia. In order to determine whether atypical lateralization of speech processing relates to reading ability, or is a correlate of being at familial risk, the current study compares the laterality index of FR children who did and did not become dyslexic, and a control group of readers without dyslexia. DL was tested in 3rd grade and in 5/6th grade. Results indicate that at both time points, all three groups have a right ear advantage, indicative of more pronounced left-hemispheric processing. However, the FR-dyslexic children are less good at reporting from the left ear than controls and FR-nondyslexic children. This impediment relates to reading fluency.

Paradoxical Benzodiazepine Response: A Rationale for Bumetanide in Neurodevelopmental Disorders?

The diuretic agent bumetanide has recently been put forward as a novel, promising treatment of behavioral symptoms in autism spectrum disorder (ASD) and related conditions. Bumetanide can decrease neuronal chloride concentrations and may thereby reinstate γ-aminobutyric acid (GABA)-ergic inhibition in patients with neurodevelopmental disorders. However, strategies to select appropriate candidates for bumetanide treatment are lacking. We hypothesized that a paradoxical response to GABA-enforcing agents such as benzodiazepines may predict the efficacy of bumetanide treatment in neurodevelopmental disorders. We describe a case of a 10-year-old girl with ASD, epilepsy, cortical dysplasia, and a 15q11.2 duplication who had exhibited marked behavioral arousal after previous treatment with clobazam, a benzodiazepine. We hypothesized that this response indicated the presence of depolarizing excitatory GABA and started bumetanide treatment with monitoring of behavior, cognition, and EEG. The treatment resulted in a marked clinical improvement in sensory behaviors, rigidity, and memory performance, which was substantiated by questionnaires and cognitive assessments. At baseline, the girl's EEG showed a depression in absolute α power, an electrographic sign previously related to ASD, which was normalized with bumetanide treatment. The effects of bumetanide on cognition and EEG seemed to mirror the "nonparadoxical" responses to benzodiazepines in healthy subjects. In addition, temporal lobe epilepsy and cortical dysplasia have both been linked to disturbed chloride homeostasis and seem to support our assumption that the observed paradoxical response was due to GABA-mediated excitation. This case highlights that a paradoxical behavioral response to GABA-enforcing drugs may constitute a framework for targeted treatment with bumetanide.

Basic auditory processing is related to familial risk, not to reading fluency: an ERP study.

Less proficient basic auditory processing has been previously connected to dyslexia. However, it is unclear whether a low proficiency level is a correlate of having a familial risk for reading problems, or whether it causes dyslexia. In this study, children's processing of amplitude rise time (ART), intensity and frequency differences was measured with event-related potentials (ERPs). ERP components of interest are components reflective of auditory change detection; the mismatch negativity (MMN) and late discriminative negativity (LDN). All groups had an MMN to changes in ART and frequency, but not to intensity. Our results indicate that fluent readers at risk for dyslexia, poor readers at risk for dyslexia and fluent reading controls have an LDN to changes in ART and frequency, though the scalp activation of frequency processing was different for familial risk children. On intensity, only controls showed an LDN. Contrary to previous findings, our results suggest that neither ART nor frequency processing is related to reading fluency. Furthermore, our results imply that diminished sensitivity to changes in intensity and differential lateralization of frequency processing should be regarded as correlates of being at familial risk for dyslexia, that do not directly relate to reading fluency.

Default spacing is the optimal spacing for word reading.

Increased interletter spacing is thought to reduce crowding effects and to enhance fluent reading. Several studies have shown beneficial effects of increased interletter spacing on reading speed and accuracy, especially in poor readers. Therefore, increased interletter spacing appears to be a relatively easy way to enhance reading performance. However, in adult readers reading speed was shown to be impeded with increased interletter spacing. Thus, findings on interletter spacing are still inconclusive. In the current study we examined the effect of a range of interletter spacings (-0.5, default, 0.5, 1, 1.5, 2) on naming fluency of monosyllabic and bisyllabic words in beginning (Grade 2) and more advanced (Grade 4) readers. Additionally we tested the effects of spacing in a subsample of poor readers. In contrast to previous findings, neither beginning nor advanced readers benefited from an increase in interletter spacing. However, they did show reduced reading fluency when letter spacing was smaller than the default spacing, which may be indicative of a crowding effect. Poor readers showed a similar pattern. We conclude that an increase in interletter spacing has no effect on word naming fluency.