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A failure to build solid letter-speech sound associations may contribute to reading impairments in developmental dyslexia. Whether this reduced neural integration of letters and speech sounds changes over time within individual children and how this relates to behavioral gains in reading skills remains unknown. In this research, we examined changes in event-related potential (ERP) measures of letter-speech sound integration over a 6-month period during which 9-year-old dyslexic readers (n=17) followed a training in letter-speech sound coupling next to their regular reading curriculum. We presented the Dutch spoken vowels /a/ and /o/ as standard and deviant stimuli in one auditory and two audiovisual oddball conditions. In one audiovisual condition (AV0), the letter 'a' was presented simultaneously with the vowels, while in the other (AV200) it was preceding vowel onset for 200 ms. Prior to the training (T1), dyslexic readers showed the expected pattern of typical auditory mismatch responses, together with the absence of letter speech sound effects in a late negativity (LN) window. After the training (T2), our results showed earlier (and enhanced) crossmodal effects in the LN window. Most interestingly, earlier LN latency at T2 was significantly related to higher behavioral accuracy in letter-speech sound coupling. On a more general level, the timing of the earlier mismatch negativity (MMN) in the simultaneous condition (AV0) measured at T1, significantly related to reading fluency at both T1 and T2 as well as with reading gains. Our findings suggest that the reduced neural integration of letters and speech sounds in dyslexic children may show moderate improvement with reading instruction and training and that behavioral improvements relate especially to individual differences in the timing of this neural integration. [ABSTRACT FROM AUTHOR]

Due to pandemic-induced lockdown(s) in 2020, dyslexia treatment was forced to move to online platforms. This study examined whether Dutch children who received online treatment progressed as much in their reading and spelling performance as children who received the usual face-to-face treatment. To this end, 254 children who received treatment-as-usual were compared to 162 children who received online treatment with Bayesian methods. The advantage of a Bayesian approach is that it can provide evidence for and against the null hypothesis whereas frequentist approaches only provide evidence against it. We found that children in the online treatment condition received slightly fewer treatment sessions but progressed equally after controlling for the number of sessions compared to the treatment-as-usual condition. These results have clinical and practical implications as they show that reading treatment can be successfully delivered online., (© 2024. The Author(s).)

The current aim is to illustrate our research on dyslexia conducted at the Developmental Psychology section of the Department of Psychology, University of Amsterdam, in collaboration with the nationwide IWAL institute for learning disabilities (now RID). The collaborative efforts are institutionalized in the Rudolf Berlin Center. The first series of studies aimed at furthering the understanding of dyslexia using a gamified tool based on an artificial script. Behavioral measures were augmented with diffusion modeling in one study, and indices derived from the electroencephalogram were used in others. Next, we illustrated a series of studies aiming to assess individuals who struggle with reading and spelling using similar research strategies. In one study, we used methodology derived from the machine learning literature. The third series of studies involved intervention targeting the phonics of language. These studies included a network analysis that is now rapidly gaining prominence in the psychopathology literature. Collectively, the studies demonstrate the importance of letter-speech sound mapping and word decoding in the acquisition of reading. It was demonstrated that focusing on these abilities may inform the prediction, classification, and intervention of reading difficulties and their neural underpinnings. A final section examined dyslexia, conceived as a neurobiological disorder. This analysis converged on the conclusion that recent developments in the psychopathology literature inspired by the focus on research domain criteria and network analysis might further the field by staying away from longstanding debates in the dyslexia literature (single vs. a multiple deficit, category vs. dimension, disorder vs. lack of skill).

Auditory selective attention forms an important foundation of children's learning by enabling the prioritisation and encoding of relevant stimuli. It may also influence reading development, which relies on metalinguistic skills including the awareness of the sound structure of spoken language. Reports of attentional impairments and speech perception difficulties in noisy environments in dyslexic readers are also suggestive of the putative contribution of auditory attention to reading development. To date, it is unclear whether non-speech selective attention and its underlying neural mechanisms are impaired in children with dyslexia and to which extent these deficits relate to individual reading and speech perception abilities in suboptimal listening conditions. In this EEG study, we assessed non-speech sustained auditory selective attention in 106 7-to-12-year-old children with and without dyslexia. Children attended to one of two tone streams, detecting occasional sequence repeats in the attended stream, and performed a speech-in-speech perception task. Results show that when children directed their attention to one stream, inter-trial-phase-coherence at the attended rate increased in fronto-central sites; this, in turn, was associated with better target detection. Behavioural and neural indices of attention did not systematically differ as a function of dyslexia diagnosis. However, behavioural indices of attention did explain individual differences in reading fluency and speech-in-speech perception abilities: both these skills were impaired in dyslexic readers. Taken together, our results show that children with dyslexia do not show group-level auditory attention deficits but these deficits may represent a risk for developing reading impairments and problems with speech perception in complex acoustic environments. RESEARCH HIGHLIGHTS: Non-speech sustained auditory selective attention modulates EEG phase coherence in children with/without dyslexia Children with dyslexia show difficulties in speech-in-speech perception Attention relates to dyslexic readers' speech-in-speech perception and reading skills Dyslexia diagnosis is not linked to behavioural/EEG indices of auditory attention., (© 2023 The Authors. Developmental Science published by John Wiley & Sons Ltd.)

The acquisition of letter-speech sound correspondences is a fundamental process underlying reading development, one that could be influenced by several linguistic and domain-general cognitive factors. In the current study, we mimicked the first steps of this process by examining behavioral trajectories of audiovisual associative learning in 110 7- to 12-year-old children with and without dyslexia. Children were asked to learn the associations between eight novel symbols and native speech sounds in a brief training and subsequently read words and pseudowords written in the artificial orthography. We then investigated the influence of auditory attention as one of the putative domain-general factors influencing associative learning. To this aim, we assessed children with experimental measures of auditory sustained selective attention and interference control. Our results showed shallower learning trajectories in children with dyslexia, especially during the later phases of the training blocks. Despite this, children with dyslexia performed similarly to typical readers on the post-training reading tests using the artificial orthography. Better auditory sustained selective attention and interference control skills predicted greater response accuracy during training. Sustained selective attention was also associated with the ability to apply these novel correspondences in the reading tests. Although this result has the limitations of a correlational design, it denotes that poor attentional skills may constitute a risk during the early stages of reading acquisition, when children start to learn letter-speech sound associations. Importantly, our findings underscore the importance of examining dynamics of learning in reading acquisition as well as individual differences in more domain-general attentional factors., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Second language proficiency may be related to first language acquisition (Ganschow & Sparks, 1991), but relatively little is known about the relation between first and second language grammatical proficiency in primary school children who are in their first stages of foreign language learning. This study aims to determine whether differences in Dutch and English vocabulary and Dutch grammar skills predict differences in English grammatical proficiency in Dutch speaking children who are in grade 4 in primary school. The selected participants are monolingual Dutch pupils (N = 152), aged 9;0-10;0. To measure the children's vocabulary the PPVT was used in Dutch (Schlichting, 2005) and in English (Dunn & Dunn, 2007). In addition, two grammar tasks in English and one in Dutch of the CELF (Semel et al., 2003) were used. The results show that English vocabulary is a strong predictor of English grammar skills, and that the Dutch vocabulary skills are weaker predictors of English grammar skills. Moreover, Dutch grammar skills predict English grammar skills for one of the grammar tasks. These results are discussed vis-à-vis hypotheses about cross-domain transfer and cross-linguistic transfer (Blom et al., 2012; Cummins, 1979; Ganschow & Sparks, 1991; Paradis, 2011; Sparks, 1995)., (© 2023. The Author(s).)

Research on the etiology of dyslexia typically uses an approach based on a single core deficit, failing to understand how variations in combinations of factors contribute to reading development and how this combination relates to intervention outcome. To fill this gap, this study explored links between 28 cognitive, environmental, and demographic variables related to dyslexia by employing a network analysis using a large clinical database of 1,257 elementary school children. We found two highly connected subparts in the network: one comprising reading fluency and accuracy measures, and one comprising intelligence-related measures. Interestingly, phoneme awareness was functionally related to the controlled and accurate processing of letter-speech sound mappings, whereas rapid automatized naming was more functionally related to the automated convergence of visual and speech information. We found evidence for the contribution of a variety of factors to (a)typical reading development, though associated with different aspects of the reading process. As such, our results contradict prevailing claims that dyslexia is caused by a single core deficit. This study shows how the network approach to psychopathology can be used to study complex interactions within the reading network and discusses future directions for more personalized interventions.

This study examined how top-down control influenced letter-speech sound (L-SS) learning, the initial phase of learning to read. In 2020, 107 Dutch children (53 boys, M age  = 106.845 months) learned eight L-SS correspondences, either preceded by goal-directed or implicit instructions. Symbol knowledge and artificial word-reading ability were assessed immediately after learning and on the subsequent day to examine the effect of sleep. Goal-directed children were faster and more efficient in learning a new script and had better learning outcomes compared to children who were not instructed about the goal of the task. This study demonstrates that directing children toward the goal can promote L-SS learning and consolidation, giving insights into how top-down control influences the initial phase of reading acquisition., (© 2023 The Authors. Child Development published by Wiley Periodicals LLC on behalf of Society for Research in Child Development.)

We performed an EEG graph analysis on data from 31 typical readers (22.27 ± 2.53 y/o) and 24 dyslexics (22.99 ± 2.29 y/o), recorded while they were engaged in an audiovisual task and during resting-state. The task simulates reading acquisition as participants learned new letter-sound mappings via feedback. EEG data was filtered for the delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), and beta (13-30 Hz) bands. We computed the Phase Lag Index (PLI) to provide an estimate of the functional connectivity between all pairs of electrodes per band. Then, networks were constructed using a Minimum Spanning Tree (MST), a unique sub-graph connecting all nodes (electrodes) without loops, aimed at minimizing bias in between groups and conditions comparisons. Both groups showed a comparable accuracy increase during task blocks, indicating that they correctly learned the new associations. The EEG results revealed lower task-specific theta connectivity, and lower theta degree correlation over both rest and task recordings, indicating less network integration in dyslexics compared to typical readers. This pattern suggests a role of theta oscillations in dyslexia and may reflect differences in task engagement between the groups, although robust correlations between MST metrics and performance indices were lacking., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Fraga-González, Smit, Van der Molen, Tijms, Stam, de Geus and Van der Molen.)

In a recent opinion article, we explained why we think that defining developmental dyslexia as a neurodevelopmental disorder and neuroimaging studies on dyslexia are useful. A recent response has made some claims of generalized misinterpretation and misconception in the field. Since that was a direct reply to our article, we would like to clarify our opinion on some of those claims., Competing Interests: The authors declare no conflict of interest.

In this study, we examined the learning of letter-speech sound correspondences within an artificial script and performed an experimental analysis of letter-speech sound learning among dyslexic and normal readers vis-à-vis phonological awareness, rapid automatized naming, reading, and spelling. Participants were provided with 20 min of training aimed at learning eight new basic letter-speech sound correspondences, followed by a short assessment of mastery of the correspondences and word-reading ability in this unfamiliar script. Our results demonstrated that brief training is moderately successful in differentiating dyslexic readers from normal readers in their ability to learn letter-speech sound correspondences. The normal readers outperformed the dyslexic readers for accuracy and speed on a letter-speech sound matching task, as well as on a word-reading task containing familiar words written in the artificial orthography. Importantly, the new artificial script-related measures were related to phonological awareness and rapid automatized naming and made a unique contribution in predicting individual differences in reading and spelling ability. Our results are consistent with the view that a fundamental letter-speech sound learning deficit is a key factor in dyslexia.

The convenience of referring to dyslexia as a neurodevelopmental disorder has been repeatedly brought into question. In this opinion article, we argue in favor of the current diagnosis of dyslexia based on the criteria of harm and dysfunction. We discuss the favorable clinical and educational outcomes of a neuroscience-informed approach of dyslexia as a disorder. Furthermore, we discuss insights derived from neuroimaging studies and their importance to address problems related to developmental dyslexia.

Developmental dyslexia may involve deficits in functional connectivity across widespread brain networks that enable fluent reading. We investigated the large-scale organization of electroencephalography (EEG) functional networks at rest in 28 dyslexics and 36 typically reading adults. For each frequency band (delta, theta alpha and beta), we assessed functional connectivity strength with the phase lag index (PLI). Network topology was examined using minimum spanning tree (MST) graphs derived from the functional connectivity matrices. We found significant group differences in the alpha band (8-13 Hz). The graph analysis indicated more interconnected nodes, in dyslexics compared to typical readers. The graph metrics were significantly correlated with age in dyslexics but not in typical readers, which may indicate more heterogeneity in maturation of brain networks in dyslexics. The present findings support the involvement of alpha oscillations in higher cognition and the sensitivity of graph metrics to characterize functional networks in adult dyslexia. Finally, the current results extend our previous findings on children.

Atypical structural properties of the brain's white matter bundles have been associated with failing reading acquisition in developmental dyslexia. Because these white matter properties may show dynamic changes with age and orthographic depth, we examined fractional anisotropy (FA) along 16 white matter tracts in 8- to 11-year-old dyslexic (DR) and typically reading (TR) children learning to read in a fairly transparent orthography (Dutch). Our results showed higher FA values in the bilateral anterior thalamic radiations of DRs and FA values of the left thalamic radiation scaled with behavioral reading-related scores. Furthermore, DRs tended to have atypical FA values in the bilateral arcuate fasciculi. Children's age additionally predicted FA values along the tracts. Together, our findings suggest differential contributions of cortical and thalamo-cortical pathways to the developing reading network in dyslexic and typical readers, possibly indicating prolonged letter-by-letter reading or increased attentional and/or working memory demands in dyslexic children during reading.

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., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Reading is a complex cognitive skill subserved by a distributed network of visual and language-related regions. Disruptions of connectivity within this network have been associated with developmental dyslexia but their relation to individual differences in the severity of reading problems remains unclear. Here we investigate whether dysfunctional connectivity scales with the level of reading dysfluency by examining EEG recordings during visual word and false font processing in 9-year-old typically reading children (TR) and two groups of dyslexic children: severely dysfluent (SDD) and moderately dysfluent (MDD) dyslexics. Results indicated weaker occipital to inferior-temporal connectivity for words in both dyslexic groups relative to TRs. Furthermore, SDDs exhibited stronger connectivity from left central to right inferior-temporal and occipital sites for words relative to TRs, and for false fonts relative to both MDDs and TRs. Importantly, reading fluency was positively related with forward and negatively with backward connectivity. Our results suggest disrupted visual processing of words in both dyslexic groups, together with a compensatory recruitment of right posterior brain regions especially in the SDDs during word and false font processing. Functional connectivity in the brain's reading network may thus depend on the level of reading dysfluency beyond group differences between dyslexic and typical readers., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)

We use a neurocognitive perspective to discuss the contribution of learning letter-speech sound (L-SS) associations and visual specialization in the initial phases of reading in dyslexic children. We review findings from associative learning studies on related cognitive skills important for establishing and consolidating L-SS associations. Then we review brain potential studies, including our own, that yielded two markers associated with reading fluency. Here we show that the marker related to visual specialization (N170) predicts word and pseudoword reading fluency in children who received additional practice in the processing of morphological word structure. Conversely, L-SS integration (indexed by mismatch negativity (MMN)) may only remain important when direct orthography to semantic conversion is not possible, such as in pseudoword reading. In addition, the correlation between these two markers supports the notion that multisensory integration facilitates visual specialization. Finally, we review the role of implicit learning and executive functions in audiovisual learning in dyslexia. Implications for remedial research are discussed and suggestions for future studies are presented., Competing Interests: The authors declare no conflict of interest.

Unlabelled: A recent account of dyslexia assumes that a failure to develop automated letter-speech sound integration might be responsible for the observed lack of reading fluency. This study uses a pre-test-training-post-test design to evaluate the effects of a training program based on letter-speech sound associations with a special focus on gains in reading fluency. A sample of 44 children with dyslexia and 23 typical readers, aged 8 to 9, was recruited. Children with dyslexia were randomly allocated to either the training program group (n = 23) or a waiting-list control group (n = 21). The training intensively focused on letter-speech sound mapping and consisted of 34 individual sessions of 45 minutes over a five month period. The children with dyslexia showed substantial reading gains for the main word reading and spelling measures after training, improving at a faster rate than typical readers and waiting-list controls. The results are interpreted within the conceptual framework assuming a multisensory integration deficit as the most proximal cause of dysfluent reading in dyslexia., Trial Registration: ISRCTN register ISRCTN12783279.

Rapid automatized naming (RAN) is widely seen as an important indicator of dyslexia. The nature of the cognitive processes involved in rapid naming is however still a topic of controversy. We hypothesized that in addition to the involvement of phonological processes and processing speed, RAN is a function of inhibition processes, in particular of interference control. A total 86 children with dyslexia and 31 normal readers were recruited. Our results revealed that in addition to phonological processing and processing speed, interference control predicts rapid naming in dyslexia, but in contrast to these other two cognitive processes, inhibition is not significantly associated with their reading and spelling skills. After variance in reading and spelling associated with processing speed, interference control and phonological processing was partialled out, naming speed was no longer consistently associated with the reading and spelling skills of children with dyslexia. Finally, dyslexic children differed from normal readers on naming speed, literacy skills, phonological processing and processing speed, but not on inhibition processes. Both theoretical and clinical interpretations of these results are discussed., (Copyright © 2014 John Wiley & Sons, Ltd.)

The acquisition of letter-speech sound associations is one of the basic requirements for fluent reading acquisition and its failure may contribute to reading difficulties in developmental dyslexia. Here we investigated event-related potential (ERP) measures of letter-speech sound integration in 9-year-old typical and dyslexic readers and specifically test their relation to individual differences in reading fluency. We employed an audiovisual oddball paradigm in typical readers (n = 20), dysfluent (n = 18) and severely dysfluent (n = 18) dyslexic children. In one auditory and two audiovisual conditions the Dutch spoken vowels/a/and/o/were presented as standard and deviant stimuli. In audiovisual blocks, the letter 'a' was presented either simultaneously (AV0), or 200 ms before (AV200) vowel sound onset. Across the three children groups, vowel deviancy in auditory blocks elicited comparable mismatch negativity (MMN) and late negativity (LN) responses. In typical readers, both audiovisual conditions (AV0 and AV200) led to enhanced MMN and LN amplitudes. In both dyslexic groups, the audiovisual LN effects were mildly reduced. Most interestingly, individual differences in reading fluency were correlated with MMN latency in the AV0 condition. A further analysis revealed that this effect was driven by a short-lived MMN effect encompassing only the N1 window in severely dysfluent dyslexics versus a longer MMN effect encompassing both the N1 and P2 windows in the other two groups. Our results confirm and extend previous findings in dyslexic children by demonstrating a deficient pattern of letter-speech sound integration depending on the level of reading dysfluency. These findings underscore the importance of considering individual differences across the entire spectrum of reading skills in addition to group differences between typical and dyslexic readers.

The specialization of visual brain areas for fast processing of printed words plays an important role in the acquisition of reading skills. Dysregulation of these areas may be among the deficits underlying developmental dyslexia. The present study examines the specificity of word activation in dyslexic children in 3rd grade by comparing early components of brain potentials elicited by visually presented words vs. strings of meaningless letter-like symbols. Results showed a more pronounced N1 component for words compared to symbols for both groups. The dyslexic group revealed larger left-lateralized, word-specific N1 responses than the typically reading group. Furthermore, positive correlations between N1 amplitudes and reading fluency were found in the dyslexic group. Our results support the notion of N1 as a sensitive index of visual word processing involved in reading fluency.

Dyslexic and non-dyslexic readers engaged in a short training aimed at learning eight basic letter-speech sound correspondences within an artificial orthography. We examined whether a letter-speech sound binding deficit is behaviorally detectable within the initial steps of learning a novel script. Both letter knowledge and word reading ability within the artificial script were assessed. An additional goal was to investigate the influence of instructional approach on the initial learning of letter-speech sound correspondences. We assigned children from both groups to one of three different training conditions: (a) explicit instruction, (b) implicit associative learning within a computer game environment, or (c) a combination of (a) and (b) in which explicit instruction is followed by implicit learning. Our results indicated that dyslexics were outperformed by the controls on a time-pressured binding task and a word reading task within the artificial orthography, providing empirical support for the view that a letter-speech sound binding deficit is a key factor in dyslexia. A combination of explicit instruction and implicit techniques proved to be a more powerful tool in the initial teaching of letter-sound correspondences than implicit training alone., (Copyright © 2013 Elsevier Inc. All rights reserved.)