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A growing number of studies has investigated temporal processing deficits in dyslexia. These studies largely focus on neural synchronization to speech. However, the importance of rise times for neural synchronization is often overlooked. Furthermore, targeted interventions, phonics-based and auditory, are being developed, but little is known about their impact. The current study investigated the impact of a 12-week tablet-based intervention. Children at risk for dyslexia received phonics-based training, either with (n = 31) or without (n = 31) auditory training, or engaged in active control training (n = 29). Additionally, neural synchronization and processing of rise times was longitudinally investigated in children with dyslexia (n = 26) and typical readers (n = 52) from pre-reading (5 years) to beginning reading age (7 years). The three time points in the longitudinal study correspond to intervention pre-test, post-test and consolidation, approximately 1 year after completing the intervention. At each time point neural synchronization was measured to sinusoidal stimuli and pulsatile stimuli with shortened rise times at syllable (4 Hz) and phoneme rates (20 Hz). Our results revealed no impact on neural synchronization at syllable and phoneme rate of the phonics-based and auditory training. However, we did reveal atypical hemispheric specialization at both syllable and phoneme rates in children with dyslexia. This was detected even before the onset of reading acquisition, pointing towards a possible causal rather than consequential mechanism in dyslexia. This study contributes to our understanding of the temporal processing deficits underlying the development of dyslexia, but also shows that the development of targeted interventions is still a work in progress. ispartof: EUROPEAN JOURNAL OF NEUROSCIENCE vol:57 issue:3 pages:547-567 ispartof: location:France status: published

Different studies have suggested that language and developmental disorders such as dyslexia are associated with a disturbance of auditory entrainment and of the functional hemispheric asymmetries during speech processing. These disorders typically result from an issue in the phonological component of language that causes problems to represent and manipulate the phonological structure of words at the syllable and/or phoneme level. We used Auditory Steady-State Responses (ASSRs) in EEG recordings to investigate the brain activation and hemisphere asymmetry of theta, alpha, beta and low-gamma range oscillations in typical readers and readers with dyslexia. The aim was to analyse whether the group differences found in previous electrode level studies were caused by a different source activation pattern or conversely was an effect that could be found on the active brain sources. We could not find differences in the brain locations of the main active brain sources. However, we observed differences in the extracted waveforms. The group average of the first DSS component of all signal-to-noise ratios of ASSR at source level were higher than the group averages at the electrode level. These analyses included a lower alpha synchronisation in adolescents with dyslexia and the possibility of compensatory mechanisms in theta, beta and low-gamma frequency bands. The main brain auditory sources were located in cortical regions around the auditory cortex. Thus, the differences observed in auditory EEG experiments would, according to our findings, have their origin in the intrinsic oscillatory mechanisms of the brain cortical sources related to speech perception.

This study examined the processing of derivational morphology and its association with early phonological skills of 24 Dutch-speaking children with dyslexia and 46 controls matched for age. A masked priming experiment was conducted where the semantic overlap between morphologically related pairs was manipulated as part of a lexical decision task. Results suggest that morphological processing is intact in children with dyslexia when compared to age-matched controls. Significant priming effects were found in each group. Children with dyslexia were found to solely benefit from the morpho-semantic information, while the morpho-orthographic form the properties of morphemes-influenced controls. Due to the longitudinal nature of the data set, an examination of early phonological awareness’s role in the later development of morphological processing skills was possible. In line with the psycholinguistic grain-size theory, fifth-grade morphological processing in children with dyslexia was found to be negatively correlated to earlier second-grade PA skills. A similar relation was not found among the controls. Results indicate a potential shift in the cognitive processes involved during reading to compensate for the observed phonological deficits of children with dyslexia.

Auditory processing of temporal information in speech is sustained by synchronized firing of neurons along the entire auditory pathway. In school‐aged children and adults with dyslexia, neural synchronization deficits have been found at cortical levels of the auditory system, however, these deficits do not appear to be present in pre‐reading children. An alternative role for subcortical synchronization in reading development and dyslexia has been suggested, but remains debated. By means of a longitudinal study, we assessed cognitive reading‐related skills and subcortical auditory steady‐state responses (80 Hz ASSRs) in a group of children before formal reading instruction (pre‐reading), after 1 year of formal reading instruction (beginning reading), and after 3 years of formal reading instruction (more advanced reading). Children were retrospectively classified into three groups based on family risk and literacy achievement: typically developing children without a family risk for dyslexia, typically developing children with a family risk for dyslexia, and children who developed dyslexia. Our results reveal that children who developed dyslexia demonstrate decreased 80 Hz ASSRs at the pre‐reading stage. This effect is no longer present after the onset of reading instruction, due to an atypical developmental increase in 80 Hz ASSRs between the pre‐reading and the beginning reading stage. A forward stepwise logistic regression analysis showed that literacy achievement was predictable with an accuracy of 90.4% based on a model including three significant predictors, that is, family risk for dyslexia (R = .31), phonological awareness (R = .23), and 80 Hz ASSRs (R = .26). Given that (1) abnormalities in subcortical ASSRs preceded reading acquisition in children who developed dyslexia and (2) subcortical ASSRs contributed to the prediction of literacy achievement, subcortical auditory synchronization deficits may constitute a pre‐reading risk factor in the emergence of dyslexia. ispartof: DEVELOPMENTAL SCIENCE vol:23 issue:6 ispartof: location:England status: published

Version of Record online: 21 June 2019 There is an ongoing debate whether phonological deficits in dyslexics should be attributed to (a) less specified representations of speech sounds, like suggested by studies in young children with a familial risk for dyslexia, or (b) to an impaired access to these phonemic representations, as suggested by studies in adults with dyslexia. These conflicting findings are rooted in between study differences in sample characteristics and/or testing techniques. The current study uses the same multivariate functional MRI (fMRI) approach as previously used in adults with dyslexia to investigate phonemic representations in 30 beginning readers with a familial risk and 24 beginning readers without a familial risk of dyslexia, of whom 20 were later retrospectively classified as dyslexic. Based on fMRI response patterns evoked by listening to different utterances of /bA/ and /dA/ sounds, multivoxel analyses indicate that the underlying activation patterns of the two phonemes were distinct in children with a low family risk but not in children with high family risk. However, no group differences were observed between children that were later classified as typical versus dyslexic readers, regardless of their family risk status, indicating that poor phonemic representations constitute a risk for dyslexia but are not sufficient to result in reading problems. We hypothesize that poor phonemic representations are trait (family risk) and not state (dyslexia) dependent, and that representational deficits only lead to reading difficulties when they are present in conjunction with other neuroanatomical or—functional deficits. This research was funded by the Research Council of KU Leuven (OT/12/044), the Research Foundation Flanders (G0920.12), postdoctoral grant of Maaike Vandermosten (Research Foundation Flanders) and the Netherlands Organization for Scientific Research (Vidi‐Grant 452‐16‐004 to Milene Bonte).

Aim. Arithmetical difficulties have been reported in pediatric mild traumatic brain injury (mTBI) but the electrophysiological abnormalities underlying these impairments remain unknown. We therefore used event-related potentials (ERP) to investigate brain functioning during arithmetic in children at the subacute phase following mTBI. Method. Participants were 16 pediatric mTBI patients at the subacute phase of recovery (10 boys; mean age 10y 8mo) and 16 well-matched controls (11 boys; mean age 10y 9mo). All children were asked to solve single-digit addition problems of small (sum ≤ 10) and large problem size (sum > 10) with simultaneous recording of ERPs. Results. Children with mTBI performed significantly less accurately (mean 81 %) than controls (mean 91 %) on the large (p = .026) but not on the small problems (p = .171). We observed no group differences in the early ERP-components P1, N1, P2, and N2 (all ps ≥ .241), yet significant group differences (p = .019) emerged for the late positivity component LPC, for which patients (mean 8.35 µV) showed smaller mean amplitudes than controls (mean 12.95 µV). Interpretation. Immediately after the injury, arithmetical difficulties in children with mTBI are particularly pronounced on more complex arithmetical problems that are less automated. This is reflected in the ERP pattern with decreased LPC but normal N2 and early ERP-components. ispartof: Developmental Medicine and Child Neurology vol:57 issue:11 pages:1042-1048 ispartof: location:England status: published

Diffusion tensor imaging (DTI) studies have shown that left temporoparietal white matter is related to phonological aspects of reading. However, DTI lacks the sensitivity to disentangle whether phonological processing is sustained by intrahemispheric connections, interhemispheric connections, or projection tracts. Spherical deconvolution (SD) is a nontensor model which enables a more accurate estimation of multiple fiber directions in crossing fiber regions. Hence, this study is the first to investigate whether the observed relation with reading aspects in left temporoparietal white matter is sustained by a particular pathway by applying a nontensor model. Second, measures of degree of diffusion anisotropy, which indirectly informs about white matter organization, were compared between DTI and SD tractography. In this study, 71 children (5–6 years old) participated. Intrahemispheric, interhemispheric, and projection pathways were delineated using DTI and SD tractography. Anisotropy indices were extracted, that is, fractional anisotropy (FA) in DTI and quantitative hindrance modulated orientational anisotropy (HMOA) in SD. DTI results show that diffusion anisotropy in both the intrahemispheric and projection tracts was positively correlated to phonological awareness; however, the effect was confounded by subjects’ motion. In SD, the relation was restricted to the left intrahemispheric connections. A model comparison suggested that FA was, relatively to HMOA, more confounded by fiber crossings; however, anisotropy indices were highly related. In sum, this study shows the potential of SD to quantify white matter microstructure in regions containing crossing fibers. More specifically, SD analyses show that phonological awareness is sustained by left intrahemispheric connections and not interhemispheric or projection tracts. Hum Brain Mapp 36:3273–3287, 2015. © 2015 Wiley Periodicals, Inc.

Children with mild intellectual disabilities (MID) appear to have particular problems in understanding the numerical meaning of Arabic digits. Therefore, we devel- oped and evaluated a numerical domino game that specifi- cally targeted the association between these digits and the numerical magnitudes they represent. Participants were 30 children with MID (M = 8.36 years), randomly assigned to either the numerical domino game or to a control color domino game. Findings revealed that both groups of chil- dren improved on a nonsymbolic comparison and arithmetic task. Most importantly, only children who played the numer- ical domino game became significantly faster from pretest to posttest on a symbolic comparison task. These findings sug- gest that numerical magnitude processing can be success- fully trained in children with MID.

This study examines the role of morphological awareness (MA) in literacy achievement and compensation in word reading of adults with dyslexia through an exploration of three questions: (1) Do adult dyslexics demonstrate a deficit in MA, and how is this potential deficit related to phonological awareness (PA)? (2) Does MA contribute independently to literacy skills equally in dyslexics and control readers? and (3) Do MA and PA skills differ in compensated and noncompensated dyslexics? A group of dyslexic and normal reading university students matched for age, education and IQ participated in this study. Group analysis demonstrated an MA deficit in dyslexics; as well, MA was found to significantly predict a greater proportion of word reading and spelling within the dyslexic group compared with the controls. Compensated dyslexics were also found to perform significantly better on the morphological task than noncompensated dyslexics. Additionally, no statistical difference was observed in MA between the normal reading controls and the compensated group (independent of PA and vocabulary). Results suggest that intact and strong MA skills contribute to the achieved compensation of this group of adults with dyslexia. Implications for MA based intervention strategies for people with dyslexia are discussed.

The main focus of this article is to develop a better understanding of the developmental trajectories of literacy and phonological skills within Dutch-speaking children. Children at high and low risk for dyslexia were followed and compared at four different moments: kindergarten and first, third and sixth grades. Three groups were then compared: (1) dyslexic readers; (2) normal readers at high risk for dyslexia; and (3) normal readers at low risk for dyslexia. Children diagnosed with dyslexia scored lower than high-risk normal readers on phonological awareness (PA), rapid automatized naming (RAN), verbal short-term memory and literacy skills. Normal readers at high risk scored between both groups, confirming that dyslexia is to be considered as a continuum rather than an all-or-none condition. Growth analyses showed that the three groups evolved similarly on all measures except for phoneme deletion and literacy measures. Finally, solely PA and RAN explained a significant amount of variance in the evolution of reading skills.

This study examined adults' use of indirect addition and direct subtraction strategies on multi-digit subtractions in the number domain up to 1,000. Seventy students who differed in their level of arithmetic ability solved multi-digit subtractions in one choice and two no-choice conditions. Against the background of recent findings in elementary subtraction, we manipulated the size of the subtrahend compared to the difference and only selected items with large distances between these two integers. Results revealed that adults frequently and efficiently apply indirect addition on multi-digit subtractions, yet adults with higher arithmetic ability performed more efficiently than those with lower arithmetic ability. In both groups, indirect addition was more efficient than direct subtraction both on subtractions with a subtrahend much larger than the difference (e.g., 713 - 695) and on subtractions with a subtrahend much smaller than the difference (e.g., 613 - 67). Unexpectedly, only adults with lower arithmetic ability fitted their strategy choices to their individual strategy performance skills. Results are interpreted in terms of mathematical and cognitive perspectives on strategy efficiency and adaptiveness.

Evidence suggests that sensitivity to coherent motion (CM) is related to reading, but its role in the etiology of developmental dyslexia remains unclear. In this longitudinal study, CM sensitivity was measured in 31 children at family risk for dyslexia and 31 low-risk controls. Children, diagnosed with dyslexia in third grade (mean age = 8 years 3 months), demonstrated reduced CM sensitivity in kindergarten (mean age = 5 years 8 months), before they had learned to read. Preschool CM thresholds in controls also uniquely predicted future literacy achievement. When reassessed in first grade, CM sensitivity in the dyslexic children was age appropriate, and CM thresholds in the controls no longer predicted literacy acquisition. These findings contribute to the debate about the developmental relations between visual processing and reading acquisition.

This longitudinal study examined the development of phonology and literacy in Dutch-speaking children at family risk of dyslexia and in matched controls. Measures were administered in kindergarten (before the start of formal reading instruction), in first and in third grade. Children, diagnosed with dyslexia in third grade, showed impaired phonological awareness (PA), verbal short-term memory, and rapid automatic naming ability (RAN) at all time points, with the deficit in PA aggravating over time. These children also performed more poorly in letter knowledge, word and nonword reading accuracy and speed, and spelling at each time point. Children at family risk of dyslexia who did not fulfil criteria for dyslexia, scored more poorly than low-risk controls on the literacy and phonological measures that required the most fine-grained phonological representations. This suggests that the family risk of dyslexia is continuous rather than discrete. Hierarchical regression analyses demonstrated that PA and RAN were initially the most important instigators of reading accuracy and reading speed, respectively. After 2 years of reading instruction, only RAN predicted reading speed and accuracy. Letter knowledge, reading accuracy, and reading speed also contributed to the development of PA.

Background. Subtraction problems of the type a2 b 1⁄4 ? can be flexibly solved by various strategies, including the indirect addition (IA) strategy ‘howmuch do I have to add to b to get a?’ Although rational task analyses indicate that IA is highly efficient especially on subtractions with small differences between the integers, little research has been done on the frequency and efficiency of this strategy on different types of subtractions.

In this paper, similarities and differences are outlined between adults with self reported learning disabilities (SRLD) drawn from the International Adult Literacy Survey (IALS) data on adult literacy in The Netherlands and Flanders. These results are discussed in terms of striking differences in the educational context within which the adults developed. The literacy skills of SRLD adults in The Netherlands are superior to SRLD adults in Flanders. This is interpreted in terms of societal acceptance of disability. Copyright © 2003 John Wiley & Sons, Ltd.

Phonological awareness’s direct influence on reading outcomes has been widely demonstrated, yet PA may also exert indirect influence on reading outcomes through other cognitive variables such as morphological awareness (MA). However, PA’s own development is dependent and influenced by many extraneous variables such as auditory processing, which could ultimately impact reading outcomes. In a group of pre-reading children with a family risk of dyslexia and low-risk controls, this study is set out to answer questions surrounding PA’s relationship at various grain sizes (syllable, onset/rime and phoneme) with measures of auditory processing (frequency modulation (FM) and an amplitude rise-time task (RT)) and MA, independent of reading experience. Group analysis revealed significant differences between high- and low-risk children on measures of MA, and PA at all grain sizes, while a trend for lower RT thresholds of high-risk children was found compared with controls. Correlational analysis demonstrated that MA is related to the composite PA score and syllable awareness. Group differences on MA and PA were re-examined including PA and MA respectively as control variables. Results exposed PA as a relevant component of MA, independent of reading experience. ispartof: Developmental Science vol:20 issue:5 pages:1-14 ispartof: location:England status: published