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Reading and arithmetic are core domains of academic achievement with marked impact on career opportunities and socioeconomic status. While associations between reading and arithmetic are well established, evidence on underlying mechanisms is inconclusive. The main goal of this study was to reevaluate the domain-specificity of established predictors and to enhance our understanding of the (co-)development of reading and arithmetic. In a sample of 885 German-speaking children, standard domain-specific predictors of reading and arithmetic were assessed before and/or at the onset of formal schooling. Reading and arithmetic skills were measured at the beginning and end of second grade. Latent variables were extracted for all relevant constructs: Grapheme-phoneme processing (phonological awareness, letter identification), RAN (RAN-objects, RAN-digits), number system knowledge (number identification, successor knowledge), and magnitude processing (non-symbolic and symbolic magnitude comparison), as well as the criterion measures reading and arithmetic. Four structural equation models tested distinct research questions. Grapheme-phoneme processing was a specific predictor of reading, and magnitude processing explained variance specific to arithmetic. RAN explained variance in both domains, and it explained variance in reading even after controlling for arithmetic. RAN and number system knowledge further explained variance in skills shared between reading and arithmetic. Reading and arithmetic entail domain-specific cognitive components, and they both require tight networks of visual, verbal, and semantic information, as reflected by RAN. This perspective provides a useful background to explain associations and dissociations between reading and arithmetic performance., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Jöbstl et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Number writing involves transcoding from number words (e.g., "thirty-two") to written digit strings (32) and is an important unique predictor of arithmetic. The existing longitudinal evidence about the relation between transcoding and arithmetic is mostly language specific. In languages with number word inversion (e.g., German), the order of tens and units is transposed in spoken number words compared with Arabic numbers. This makes transcoding more challenging than in languages without number word inversion (e.g., English). In the current study, we aimed to understand whether the contribution of number writing to the development of arithmetic is similar in languages with and without number word inversion. German-speaking children (n = 166) and English-speaking children (n = 201) were followed over the first 3 years of primary school. In a series of multiple linear regressions, we tested whether number writing of multi-digit numbers was a significant unique predictor of arithmetic after controlling for well-known non-numerical predictors (nonverbal reasoning and working memory) and numerical predictors (symbolic and nonsymbolic magnitude comparison). Number writing in Grade 1 predicted arithmetic in Grades 1, 2, and 3 over and above the other predictors. Crucially, number writing performance was of comparable importance for arithmetic development in German- and English-speaking children. Our findings extend previous evidence by showing that transcoding predicts the development of arithmetic skills during the first 3 years of primary school in languages with and without number word inversion., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

While reading is among the most important and well-researched topics of developmental psychology, sublexical regularities and how these regularities relate to reading skills have attracted less interest so far. This study tested general orthographic knowledge (GOK) using an indirect reaction time (RT)-based task, in which participants had to detect letters appearing within frequent and infrequent letter clusters. The aim of the method was to minimise the roles of phonological activation and metalinguistic decision. Three different age-groups of German-speaking individuals were tested: first graders ( N  = 60), third graders ( N  = 68), and adults ( N  = 44). Orthographic regularity affected RTs in all three groups, with significantly lower RTs for frequent than for infrequent clusters. The indirect measure of GOK did not show an association with reading measures in first graders and adults, but in the case of third graders it explained variance over and above age and phonological skills. This study provides evidence for phonology-independent GOK, at least in third graders.

Converting visual-Arabic digits to auditory number words and vice versa is seemingly effortless for adults. However, it is still unclear whether this process takes place automatically and whether accessing the underlying magnitude representation is necessary during this process. In two event-related potential (ERP) experiments, adults were presented with identical (e.g., "one" and 1) or non-identical (e.g., "one" and 9) number pairs, either unimodally (two visual-Arabic digits) or cross-format (an auditory number word and a visual-Arabic digit). In Experiment 1 (N=17), active task demands required numerical judgments, whereas this was not the case in Experiment 2 (N=19). We found pronounced early ERP markers of numerical identity unimodally in both experiments. In the cross-format conditions, however, we only observed late neural correlates of identity and only if the task required semantic number processing (Experiment 1). These findings suggest that unimodal pairs of digits are automatically integrated, whereas cross-format integration of numerical information occurs more slowly and involves semantic access., 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 Finke, Kemény, Clayton, Banfi, Steiner, Perchtold-Stefan, Papousek, Göbel and Landerl.)

What are the cognitive mechanisms supporting non-symbolic and symbolic order processing? Preliminary evidence suggests that non-symbolic and symbolic order processing are partly distinct constructs. The precise mechanisms supporting these skills, however, are still unclear. Moreover, predictive patterns may undergo dynamic developmental changes during the first years of formal schooling. This study investigates the contribution of theoretically relevant constructs (non-symbolic and symbolic magnitude comparison, counting and storage and manipulation components of verbal and visuo-spatial working memory) to performance and developmental change in non-symbolic and symbolic numerical order processing. We followed 157 children longitudinally from Grade 1 to 3. In the order judgement tasks, children decided whether or not triplets of dots or digits were arranged in numerically ascending order. Non-symbolic magnitude comparison and visuo-spatial manipulation were significant predictors of initial performance in both non-symbolic and symbolic ordering. In line with our expectations, counting skills contributed additional variance to the prediction of symbolic, but not of non-symbolic ordering. Developmental change in ordering performance from Grade 1 to 2 was predicted by symbolic comparison skills and visuo-spatial manipulation. None of the predictors explained variance in developmental change from Grade 2 to 3. Taken together, the present results provide robust evidence for a general involvement of pair-wise magnitude comparison and visuo-spatial manipulation in numerical ordering, irrespective of the number format. Importantly, counting-based mechanisms appear to be a unique predictor of symbolic ordering. We thus conclude that there is only a partial overlap of the cognitive mechanisms underlying non-symbolic and symbolic order processing., Competing Interests: The authors have declared that no competing interests exist.

Developmental dyslexia (DD) is a learning disorder affecting the ability to read, with a heritability of 40-60%. A notable part of this heritability remains unexplained, and large genetic studies are warranted to identify new susceptibility genes and clarify the genetic bases of dyslexia. We carried out a genome-wide association study (GWAS) on 2274 dyslexia cases and 6272 controls, testing associations at the single variant, gene, and pathway level, and estimating heritability using single-nucleotide polymorphism (SNP) data. We also calculated polygenic scores (PGSs) based on large-scale GWAS data for different neuropsychiatric disorders and cortical brain measures, educational attainment, and fluid intelligence, testing them for association with dyslexia status in our sample. We observed statistically significant (p  < 2.8 × 10 -6 ) enrichment of associations at the gene level, for LOC388780 (20p13; uncharacterized gene), and for VEPH1 (3q25), a gene implicated in brain development. We estimated an SNP-based heritability of 20-25% for DD, and observed significant associations of dyslexia risk with PGSs for attention deficit hyperactivity disorder (at p T  = 0.05 in the training GWAS: OR = 1.23[1.16; 1.30] per standard deviation increase; p  = 8 × 10 -13 ), bipolar disorder (1.53[1.44; 1.63]; p = 1 × 10 -43 ), schizophrenia (1.36[1.28; 1.45]; p = 4 × 10 -22 ), psychiatric cross-disorder susceptibility (1.23[1.16; 1.30]; p = 3 × 10 -12 ), cortical thickness of the transverse temporal gyrus (0.90[0.86; 0.96]; p = 5 × 10 -4 ), educational attainment (0.86[0.82; 0.91]; p = 2 × 10 -7 ), and intelligence (0.72[0.68; 0.76]; p = 9 × 10 -29 ). This study suggests an important contribution of common genetic variants to dyslexia risk, and novel genomic overlaps with psychiatric conditions like bipolar disorder, schizophrenia, and cross-disorder susceptibility. Moreover, it revealed the presence of shared genetic foundations with a neural correlate previously implicated in dyslexia by neuroimaging evidence., (© 2020. The Author(s).)

There is an ongoing debate concerning the extent to which deficits in reading and spelling share cognitive components and whether they rely, in a similar fashion, on sublexical and lexical pathways of word processing. The present study investigates whether the neural substrates of word processing differ in children with various patterns of reading and spelling deficits. Using functional magnetic resonance imaging, we compared written and auditory processing in three groups of 9-13-year olds (N = 104): (1) with age-adequate reading and spelling skills; (2) with reading and spelling deficits (i.e., dyslexia); (3) with isolated spelling deficits but without reading deficits. In visual word processing, both deficit groups showed hypoactivations in the posterior superior temporal cortex compared to typical readers and spellers. Only children with dyslexia exhibited hypoactivations in the ventral occipito-temporal cortex compared to the two groups of typical readers. This is the result of an atypical pattern of higher activity in the occipito-temporal cortex for non-linguistic visual stimuli than for words, indicating lower selectivity. The print-speech convergence was reduced in the two deficit groups. Impairments in lexico-orthographic regions in a reading-based task were associated primarily with reading deficits, whereas alterations in the sublexical word processing route could be considered common for both reading and spelling deficits. These findings highlight the partly distinct alterations of the language network related to reading and spelling deficits.

Does number-word structure have a long-lasting impact on transcoding? Contrary to English, German number words comprise decade-unit inversion (e.g., vierundzwanzig is literally translated as four-and-twenty). To investigate the mental representation of numbers, we tested the effect of visual and linguistic-morphological characteristics on the development of verbal-visual transcoding. In a longitudinal cross-linguistic design, response times (RTs) in a number-matching experiment were analyzed in Grade 2 (119 German-speaking and 179 English-speaking children) and in Grade 3 (131 German-speaking and 160 English-speaking children). To test for long-term effects, the same experiment was given to 38 German-speaking and 42 English-speaking adults. Participants needed to decide whether a spoken number matched a subsequent visual Arabic number. Systematic variation of digits in the nonmatching distractors allowed comparison of three different transcoding accounts (lexicalization, visual, and linguistic-morphological). German speakers were generally slower in rejecting inverted number distractors than English speakers. Across age groups, German speakers were more distracted by Arabic numbers that included the correct unit digit, whereas English speakers showed stronger distraction when the correct decade digit was included. These RT patterns reflect differences in number-word morphology. The individual cost of rejecting an inverted distractor (inversion effect) predicted arithmetic skills in German-speaking second-graders only. The moderate relationship between the efficiency to identify a matching number and arithmetic performance could be observed cross-linguistically in all age groups but was not significant in German-speaking adults. Thus, findings provide consistent evidence of a persistent impact of number-word structure on number processing, whereas the relationship with arithmetic performance was particularly pronounced in young children., (Crown Copyright © 2020. Published by Elsevier Inc. All rights reserved.)

We examined the relation between home literacy environment (HLE) and early literacy development in a sample of children learning four alphabetic orthographies varying in orthographic consistency (English, Dutch, German, and Greek). Seven hundred and fourteen children were followed from Grade 1 to Grade 2 and tested on emergent literacy skills (vocabulary, letter knowledge, and phonological awareness) at the beginning of Grade 1 and on word reading fluency and spelling at the end of Grade 1, the beginning of Grade 2, and the end of Grade 2. Their parents responded to a questionnaire assessing HLE [parent teaching (PT), shared book reading (SBR), access to literacy resources (ALR)] at the beginning of Grade 1. Results showed first that PT was associated with letter knowledge or phonological awareness in Dutch and Greek, while ALR was associated with emergent literacy skills in all languages. SBR did not predict any cognitive or early literacy skills in any language. Second, PT and ALR had indirect effects on literacy outcomes via different emergent literacy skills in all languages. These findings suggest that not all HLE components are equally important for emergent literacy skills, reading fluency, and spelling. No specific trend in the role of orthographic consistency in the aforementioned relations emerged, which suggests that other factors may account for the observed differences across languages when children start receiving formal reading instruction in Grade 1., (Copyright © 2020 Inoue, Manolitsis, de Jong, Landerl, Parrila and Georgiou.)

The nature of the relation between non-symbolic and symbolic magnitude processing in the prediction of arithmetic remains a hotly debated subject. This longitudinal study examined whether the influence of non-symbolic magnitude processing on arithmetic is mediated by symbolic processing skills. A sample of 130 children with age-adequate ( N = 73) or below-average ( N = 57) achievement in early arithmetic was followed from the end of Grade 1 (mean age: 86.9 months) through the beginning of Grade 4. Symbolic comparison of one- and two-digit numbers serially mediated the effect of non-symbolic comparison on later arithmetic. These results support a developmental model in which non-symbolic processing provides a scaffold for single-digit processing, which in turn influences multi-digit processing and arithmetic. In conclusion, both non-symbolic and symbolic processing play an important role in the development of arithmetic during primary school and might be valuable long-term indicators for the early identification of children at risk for low achievement in arithmetic., (Copyright © 2020 Finke, Freudenthaler and Landerl.)

We examined the cross-lagged relations between reading and spelling in five alphabetic orthographies varying in consistency (English, French, Dutch, German, and Greek). Nine hundred and forty-one children were followed from Grade 1 to Grade 2 and were tested on word and pseudoword reading fluency and on spelling to dictation. Results indicated that the relations across languages were unidirectional: Earlier reading predicted subsequent spelling. However, we also found significant differences between languages in the strength of the effects of earlier reading on subsequent spelling. These findings suggest that, once children master decoding, the observed differences between languages are not related to the direction of the effects but to the strength of the effects from reading to spelling. Theoretical and practical implications are discussed., (© 2019 Society for Research in Child Development.)

Objective: Reading fluency deficits characteristic for reading disorders (RD; F81.0) have been shown to be strongly associated with slow naming speed (e.g. in rapid automatized naming tasks). In contrast, children with an isolated spelling disorder in the context of unimpaired reading skills (iSD; F81.1) show naming speed task performances that are similar to typically developing (TD) children. However, the exact nature of the naming speed deficit and its relation to RD and the question whether children with iSD are also on the neurophysiological level similar to TD children is still unresolved., Methods: The time-course and scalp topography of event-related potentials (ERP) activity recorded during a delayed digit-naming task was investigated in ten-year-old children with RD and iSD compared to a TD group., Results: ERP activity differed between the RD and the TD group at around 300 ms after stimulus presentation (left occipito-temporal P2). In contrast, there were no neurophysiological differences between the TD and the iSD group. The P2 component correlated with behavioural performance on the RAN task., Conclusions: Slow naming speed in RD might result from a slowed-down access and prolonged processing of the word (lexical) form., Significance: The study establishes a relation between neurophysiological processes of naming tasks and RD., (Copyright © 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Deficits in reading fluency and in spelling can dissociate during development, resulting in groups with reading deficit only (RD), spelling deficit only (SD) and combined reading and spelling deficit (RSD). The current study investigated the one-to-two-year longitudinal stability of these subgroups in 167 German-speaking children. Reading fluency deficits (irrespective of spelling skills) were stable over time, while spelling deficits were stable in the RSD-group but not in the SD-group. Lower stability in the SD-group resulted from the fact that many children improved their spelling skills over time. Improvement in spelling was associated with good performance in phoneme awareness together with intact RAN and decoding skills., (© 2019 The Author(s). Published with license by Taylor & Francis Group, LLC.)

Dissociations between reading and spelling problems are likely to be associated with different underlying cognitive deficits, and with different deficits in orthographic learning. In order to understand these differences, the current study examined orthographic learning using a printed-word learning paradigm. Children (4th grade) with isolated reading, isolated spelling and combined reading and spelling problems were compared to children with age appropriate reading and spelling skills on their performance during learning novel words and symbols (non-verbal control condition), and during immediate and delayed reading and spelling recall tasks. No group differences occurred in the non-verbal control condition. In the verbal condition, initial learning was intact in all groups, but differences occurred during recall tasks. Children with reading fluency deficits showed slower reading times, while children with spelling deficits were less accurate, both in reading and spelling recall. Children with isolated spelling problems showed no difficulties in immediate spelling recall, but had problems in remembering the spellings 2 hours later. The results suggest that different orthographic learning deficits underlie reading fluency and spelling problems: Children with isolated reading fluency deficits have no difficulties in building-up orthographic representations, but access to these representations is slowed down while children with isolated spelling deficits have problems in storing precise orthographic representations in long-term memory.

Background: Reading disorder (RD) and mathematics disorder (MD) frequently co-occur. However, the exact comorbidity rates differ largely between studies. Given that MD is characterised by high heterogeneity on the symptom level, differences in comorbidity rates may result from different mathematical subskills used to define MD. Comorbidity rates with RD are likely to be higher when MD is measured by mathematical subskills that do not only build on number processing, but also require language (i.e. arithmetic fluency), than when measured by magnitude processing skills., Methods: The association between literacy, arithmetic fluency and magnitude processing as well as the overlap between deficits in these domains were assessed in a representative sample of 1,454 third Graders., Results: Associations were significantly higher between literacy and arithmetic, than between literacy and magnitude processing. This was also reflected in comorbidity rates: comorbidity rates between literacy and arithmetic deficits were four times higher than expected by chance, whereas comorbidity rates between literacy and magnitude processing deficits did not exceed chance rate. Deficits in the two mathematical subskills showed some overlap, but also revealed dissociations, corroborating the high heterogeneity of MD. Results are interpreted within a multiple-deficit framework and implications for diagnosis and intervention are discussed., Conclusions: The overlap between RD and MD depends on the subskills used to define MD. Due to shared domain-general factors mathematical subskills that draw on language skills are more strongly associated with literacy than those that do not require language. The findings further indicate that the same symptom, such as deficits in arithmetic, can be associated with different cognitive deficits, a deficit in language skills or a deficit in number processing., (© 2018 Association for Child and Adolescent Mental Health.)

The present study investigated whether children with a typical dyslexia profile and children with isolated spelling deficits show a distinct pattern of white matter alteration compared with typically developing peers. Relevant studies on the topic are scarce, rely on small samples, and often suffer from the limitations of conventional tensor-based methods. The present Constrained Spherical Deconvolution study includes 27 children with typical reading and spelling skills, 21 children with dyslexia and 21 children with isolated spelling deficits. Group differences along major white matter tracts were quantified utilizing the Automated Fiber Quantification software and a lateralization index was calculated in order to investigate the structural asymmetry of the tracts. The two deficit groups mostly displayed different patterns of white matter alterations, located in the bilateral inferior longitudinal fasciculi, right superior longitudinal fasciculus, and cingulum for the group with dyslexia and in the left arcuate fasciculus for the group with isolated spelling deficits. The two deficit groups differed also with respect to structural asymmetry. Children with dyslexia did not show the typical leftward asymmetry of the arcuate fasciculus, whereas the group with isolated spelling deficits showed absent rightward asymmetry of the inferior fronto-occipital fasciculus. This study adds evidence to the notion that different profiles of combined or isolated reading and spelling deficits are associated with different neural signatures., (© 2018 The Authors. Human Brain Mapping published by Wiley Periodicals, Inc.)

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 -8 ) on rapid automatized naming of letters (RANlet) for variants on 18q12.2, within MIR924HG (micro-RNA 924 host gene; rs17663182 p = 4.73 × 10 -9 ), and a suggestive association on 8q12.3 within NKAIN3 (encoding a cation transporter; rs16928927, p = 2.25 × 10 -8 ). rs17663182 (18q12.2) also showed genome-wide significant multivariate associations with RAN measures (p = 1.15 × 10 -8 ) and with all the cognitive traits tested (p = 3.07 × 10 -8 ), suggesting (relational) pleiotropic effects of this variant. A polygenic risk score (PRS) analysis revealed significant genetic overlaps of some of the DD-related traits with educational attainment (EDUyears) and ADHD. Reading and spelling abilities were positively associated with EDUyears (p ~ [10 -5 -10 -7 ]) and negatively associated with ADHD PRS (p ~ [10 -8 -10 -17 ]). This corroborates a long-standing hypothesis on the partly shared genetic etiology of DD and ADHD, at the genome-wide level. Our findings suggest new candidate DD susceptibility genes and provide new insights into the genetics of dyslexia and its comorbities.

Efficient and automatic integration of letters and speech sounds is assumed to enable fluent word recognition and may in turn also underlie the build-up of high-quality orthographic representations, which are relevant for accurate spelling. While previous research showed that developmental dyslexia is associated with deficient letter-speech sound integration, these studies did not differentiate between subcomponents of literacy skills. In order to investigate whether deficient letter-speech sound integration is associated with deficits in reading and/or spelling, three groups of third graders were recruited: (1) children with combined deficits in reading and spelling (RSD, N = 10); (2) children with isolated spelling deficit (ISD, N = 17); and (3) typically developing children (TD, N = 21). We assessed the neural correlates (EEG) of letter-speech sound integration using a Stroop-like interference paradigm: participants had to decide whether two visually presented letters look identical. In case of non-identical letter pairs, conflict items were the same letter in lower and upper case (e.g., "T t"), while non-conflict items were different letters (e.g., "T k"). In terms of behavioral results, each of the three groups exhibited a comparable amount of conflict-related reaction time (RT) increase, which may be a sign for no general inhibitory deficits. Event-related potentials (ERPs), on the other hand, revealed group-based differences: the amplitudes of the centro-parietal conflict slow potential (cSP) were increased for conflicting items in typical readers as well as the ISD group. Preliminary results suggest that this effect was missing for children with RSD. The results suggest that deficits in automatized letter-speech sound associations are associated with reading deficit, but no impairment was observed in spelling deficit.

Reading and spelling abilities are thought to be highly correlated during development, and orthographic knowledge is assumed to underpin both literacy skills. Interestingly, recent studies showed that reading and spelling skills can also dissociate. The current study investigated whether spelling skills (indicating orthographic knowledge) are associated with the application of orthographic strategies during reading. We examined eye movements of 137 third- and fourth-graders who were either good or poor readers with or without a spelling deficit: 43 children with typical reading and spelling skills, 28 with isolated spelling deficits, 28 with isolated reading deficits, and 38 with combined reading and spelling deficits. Although we expected to find reduced reliance on orthographic reading processes among poor spellers, this was evident for the group with combined deficits only. Both isolated deficit groups applied sublexical and lexical processes in a similar amount to typically developing children. Our findings suggest that reading rests on orthographic strategies even if lexical representations are poor as indicated by a deficit in spelling skills. Findings also show that dysfluent reading does not result only from overreliance on decoding., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Findings on the neurophysiological correlates of developmental dyslexia are mixed, due to the differential conceptualization of the impairment. Studies differ on whether participants with developmental dyslexia are recruited based on reading skills only or reading as well as spelling skills. The current study contrasts the contribution of impaired reading and spelling to ERP correlates of print sensitivity, lexico-semantic access and sensitivity to orthographic regularities. Four groups of children were recruited: isolated reading deficit, isolated spelling deficit, combined reading and spelling deficit, and typically developing. Their neural correlates (EEG) of word, pseudohomophone, and pseudoword reading, as well as false font processing were compared. 1) All groups showed higher N1 amplitudes to letters than to false fonts. 2) Good spellers exhibited more negative N400 amplitudes for meaningless (pseudowords) than for meaningful stimuli (words and pseudohomophones). This effect was not observed in poor spellers. 3) Good readers showed sensitivity to orthographic regularities in a later time window (700-900 ms), whereas this was not the case for poor readers. 1) Print sensitivity is not affected by reading and/or spelling deficit in German-speaking 3rd graders. 2) Spelling deficits are associated with a reduced orthographic lexicon, 3) Reading deficits are associated with atypical use of sublexical information. As this effect was observed after lexico-semantic access, the results are discussed in terms of a possible orthographic reanalysis hypothesis., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)

An impairment in the visual attention span (VAS) has been suggested to hamper reading performance of individuals with dyslexia. It is not clear, however, if the very nature of the deficit is visual or verbal and, importantly, if it affects spelling skills as well. The current study investigated VAS by means of forced choice tasks with letters and symbols in a sample of third and fourth graders with age-adequate reading and spelling skills (n = 43), a typical dyslexia profile with combined reading and spelling deficits (n = 26) and isolated spelling deficits (n = 32). The task was devised to contain low phonological short-term memory load and to overcome the limitations of oral reports. Notably, eye-movements were monitored to control that children fixated the center of the display when stimuli were presented. Results yielded no main effect of group as well as no group-related interactions, thus showing that children with dyslexia and isolated spelling deficits did not manifest a VAS deficit for letters or symbols once certain methodological aspects were controlled for. The present results could not replicate previous evidence for the involvement of VAS in reading and dyslexia., Competing Interests: The authors have declared that no competing interests exist.

Objective: In consistent orthographies, isolated reading disorders (iRD) and isolated spelling disorders (iSD) are nearly as common as combined reading-spelling disorders (cRSD). However, the exact nature of the underlying word processing deficits in isolated versus combined literacy deficits are not well understood yet., Methods: We applied a phonological lexical decision task (including words, pseudohomophones, legal and illegal pseudowords) during ERP recording to investigate the neurophysiological correlates of lexical and sublexical word-processing in children with iRD, iSD and cRSD compared to typically developing (TD) 9-year-olds., Results: TD children showed enhanced early sensitivity (N170) for word material and for the violation of orthographic rules compared to the other groups. Lexical orthographic effects (higher LPC amplitude for words than for pseudohomophones) were the same in the TD and iRD groups, although processing took longer in children with iRD. In the iSD and cRSD groups, lexical orthographic effects were evident and stable over time only for correctly spelled words., Conclusions: Orthographic representations were intact in iRD children, but word processing took longer compared to TD. Children with spelling disorders had partly missing orthographic representations., Significance: Our study is the first to specify the underlying neurophysiology of word processing deficits associated with isolated literacy deficits., (Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Dyslexia in consistent orthographies like German is characterized by dysfluent reading, which is often assumed to result from failure to build up an orthographic lexicon and overreliance on decoding. However, earlier evidence indicates effects of lexical processing at least in some German dyslexic readers. We investigated variations in reading style in an eye-tracking paradigm with German dysfluent 3rd and 4th graders. Twenty-six TypFix-readers (fixation counts within the range of 47 age-matched typical readers) were compared with 42 HighFix-readers (increased fixation counts). Both groups showed lexical access: Words were read more efficiently than nonwords and pseudohomophones. TypFix-readers showed stronger reliance on lexical reading than HighFix-readers (smaller length effects for number of fixations and total reading time, stronger lexicality effects for gaze duration, stronger word-pseudohomophone effects for mean saccade amplitude). We conclude that in both groups, sublexical and lexical reading processes were impaired due to inefficient visual-verbal integration.

Dyslexia has been claimed to be causally related to deficits in visuo-spatial attention. In particular, inefficient shifting of visual attention during spatial cueing paradigms is assumed to be associated with problems in graphemic parsing during sublexical reading. The current study investigated visuo-spatial attention performance in an exogenous cueing paradigm in a large sample (N = 191) of third and fourth graders with different reading and spelling profiles (controls, isolated reading deficit, isolated spelling deficit, combined deficit in reading and spelling). Once individual variability in reaction times was taken into account by means of z-transformation, a cueing deficit (i.e. no significant difference between valid and invalid trials) was found for children with combined deficits in reading and spelling. However, poor readers without spelling problems showed a cueing effect comparable to controls, but exhibited a particularly strong right-over-left advantage (position effect). Isolated poor spellers showed a significant cueing effect, but no position effect. While we replicated earlier findings of a reduced cueing effect among poor nonword readers (indicating deficits in sublexical processing), we also found a reduced cueing effect among children with particularly poor orthographic spelling (indicating deficits in lexical processing). Thus, earlier claims of a specific association with nonword reading could not be confirmed. Controlling for ADHD-symptoms reported in a parental questionnaire did not impact on the statistical analysis, indicating that cueing deficits are not caused by more general attentional limitations. Between 31 and 48% of participants in the three reading and/or spelling deficit groups as well as 32% of the control group showed reduced spatial cueing. These findings indicate a significant, but moderate association between certain aspects of visuo-spatial attention and subcomponents of written language processing, the causal status of which is yet unclear.

The reading and spelling deficits characteristic of developmental dyslexia (dyslexia) have been related to problems in phonological processing and in learning associations between letters and speech-sounds. Even when children with dyslexia have learned the letters and their corresponding speech sounds, letter-speech sound associations might still be less automatized compared to children with age-adequate literacy skills. In order to examine automaticity in letter-speech sound associations and to overcome some of the disadvantages associated with the frequently used visual-auditory oddball paradigm, we developed a novel electrophysiological letter-speech sound interference paradigm. This letter-speech sound interference paradigm was applied in a group of 9-year-old children with dyslexia ( n = 36) and a group of typically developing (TD) children of similar age ( n = 37). Participants had to indicate whether two letters look visually the same. In the incongruent condition (e.g., the letter pair A-a) there was a conflict between the visual information and the automatically activated phonological information; although the visual appearance of the two letters is different, they are both associated with the same speech sound. This conflict resulted in slower response times (RTs) in the incongruent than in the congruent (e.g., the letter pair A-e) condition. Furthermore, in the TD control group, the conflict resulted in fast and strong event-related potential (ERP) effects reflected in less negative N1 amplitudes and more positive conflict slow potentials (cSP) in the incongruent than in the congruent condition. However, the dyslexic group did not show any conflict-related ERP effects, implying that letter-speech sound associations are less automatized in this group. Furthermore, we examined general visual conflict processing in a control visual interference task, using false fonts. The conflict in this experiment was based purely on the visual similarity of the presented objects. Visual conflict resulted in slower RTs, less negative N2 amplitudes and more positive cSP in both groups. Thus, on a general, basic level, visual conflict processing does not seem to be affected in children with dyslexia.

The present study aimed to define differences between silent and oral reading with respect to spatial and temporal eye movement parameters. Eye movements of 22 German-speaking adolescents (14 females; mean age = 13;6 years;months) were recorded while reading an age-appropriate text silently and orally. Preschool cognitive abilities were assessed at the participants' age of 5;7 (years;months) using the Kaufman Assessment Battery for Children. The participants' reading speed and reading comprehension at the age of 13;6 (years;months) were determined using a standardized inventory to evaluate silent reading skills in German readers (Lesegeschwindigkeits- und -verständnistest für Klassen 6-12). The results show that (i) reading mode significantly influenced both spatial and temporal characteristics of eye movement patterns; (ii) articulation decreased the consistency of intraindividual reading performances with regard to a significant number of eye movement parameters; (iii) reading skills predicted the majority of eye movement parameters during silent reading, but influenced only a restricted number of eye movement parameters when reading orally; (iv) differences with respect to a subset of eye movement parameters increased with reading skills; (v) an overall preschool cognitive performance score predicted reading skills at the age of 13;6 (years;months), but not eye movement patterns during either silent or oral reading. However, we found a few significant correlations between preschool performances on subscales of sequential and simultaneous processing and eye movement parameters for both reading modes. Overall, the findings suggest that eye movement patterns depend on the reading mode. Preschool cognitive abilities were more closely related to eye movement patterns of oral than silent reading, while reading skills predicted eye movement patterns during silent reading, but less so during oral reading., Competing Interests: The authors have declared that no competing interests exist.

Differences between languages in terms of number naming systems may lead to performance differences in number processing. The current study focused on differences concerning the order of decades and units in two-digit number words (i.e., unit-decade order in German but decade-unit order in French) and how they affect number magnitude judgments. Participants performed basic numerical tasks, namely two-digit number magnitude judgments, and we used the compatibility effect (Nuerk et al. in Cognition 82(1):B25-B33, 2001) as a hallmark of language influence on numbers. In the first part we aimed to understand the influence of language on compatibility effects in adults coming from German or French monolingual and German-French bilingual groups (Experiment 1). The second part examined how this language influence develops at different stages of language acquisition in individuals with increasing bilingual proficiency (Experiment 2). Language systematically influenced magnitude judgments such that: (a) The spoken language(s) modulated magnitude judgments presented as Arabic digits, and (b) bilinguals' progressive language mastery impacted magnitude judgments presented as number words. Taken together, the current results suggest that the order of decades and units in verbal numbers may qualitatively influence magnitude judgments in bilinguals and monolinguals, providing new insights into how number processing can be influenced by language(s).

High comorbidity rates between reading disorder (RD) and mathematics disorder (MD) indicate that, although the cognitive core deficits underlying these disorders are distinct, additional domain-general risk factors might be shared between the disorders. Three domain-general cognitive abilities were investigated in children with RD and MD: processing speed, temporal processing, and working memory. Since attention problems frequently co-occur with learning disorders, the study examined whether these three factors, which are known to be associated with attention problems, account for the comorbidity between these disorders. The sample comprised 99 primary school children in four groups: children with RD, children with MD, children with both disorders (RD+MD), and typically developing children (TD controls). Measures of processing speed, temporal processing, and memory were analyzed in a series of ANCOVAs including attention ratings as covariate. All three risk factors were associated with poor attention. After controlling for attention, associations with RD and MD differed: Although deficits in verbal memory were associated with both RD and MD, reduced processing speed was related to RD, but not MD; and the association with RD was restricted to processing speed for familiar nameable symbols. In contrast, impairments in temporal processing and visuospatial memory were associated with MD, but not RD., (© Hammill Institute on Disabilities 2014.)

Solving arithmetic problems is a cognitive task that heavily relies on language processing. One might thus wonder whether this language-reliance leads to qualitative differences (e.g., greater difficulties, error types, etc.) in arithmetic for bilingual individuals who frequently have to solve arithmetic problems in more than one language. The present study investigated how proficiency in two languages interacts with arithmetic problem solving throughout language acquisition in adolescents and young adults. Additionally, we examined whether the number word structure that is specific to a given language plays a role in number processing over and above bilingual proficiency. We addressed these issues in a German-French educational bilingual setting, where there is a progressive transition from German to French as teaching language. Importantly, German and French number naming structures differ clearly, as two-digit number names follow a unit-ten order in German, but a ten-unit order in French. We implemented a transversal developmental design in which bilingual pupils from grades 7, 8, 10, 11, and young adults were asked to solve simple and complex additions in both languages. The results confirmed that language proficiency is crucial especially for complex addition computation. Simple additions in contrast can be retrieved equally well in both languages after extended language practice. Additional analyses revealed that over and above language proficiency, language-specific number word structures (e.g., unit-ten vs. ten-unit) also induced significant modulations of bilinguals' arithmetic performances. Taken together, these findings support the view of a strong relation between language and arithmetic in bilinguals.

The current study investigated the time course of cross-linguistic differences in word recognition. We recorded eye movements of German and English children and adults while reading closely matched sentences, each including a target word manipulated for length and frequency. Results showed differential word recognition processes for both developing and skilled readers. Children of the two orthographies did not differ in terms of total word processing time, but this equal outcome was achieved quite differently. Whereas German children relied on small-unit processing early in word recognition, English children applied small-unit decoding only upon rereading-possibly when experiencing difficulties in integrating an unfamiliar word into the sentence context. Rather unexpectedly, cross-linguistic differences were also found in adults in that English adults showed longer processing times than German adults for nonwords. Thus, although orthographic consistency does play a major role in reading development, cross-linguistic differences are detectable even in skilled adult readers., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Dyslexia is one of the most common childhood disorders with a prevalence of around 5-10% in school-age children. Although an important genetic component is known to have a role in the aetiology of dyslexia, we are far from understanding the molecular mechanisms leading to the disorder. Several candidate genes have been implicated in dyslexia, including DYX1C1, DCDC2, KIAA0319, and the MRPL19/C2ORF3 locus, each with reports of both positive and no replications. We generated a European cross-linguistic sample of school-age children - the NeuroDys cohort - that includes more than 900 individuals with dyslexia, sampled with homogenous inclusion criteria across eight European countries, and a comparable number of controls. Here, we describe association analysis of the dyslexia candidate genes/locus in the NeuroDys cohort. We performed both case-control and quantitative association analyses of single markers and haplotypes previously reported to be dyslexia-associated. Although we observed association signals in samples from single countries, we did not find any marker or haplotype that was significantly associated with either case-control status or quantitative measurements of word-reading or spelling in the meta-analysis of all eight countries combined. Like in other neurocognitive disorders, our findings underline the need for larger sample sizes to validate possibly weak genetic effects.

Numerosity discrimination has been demonstrated in newborns, but not in fetuses. Fetal magnetoencephalography allows non-invasive investigation of neural responses in neonates and fetuses. During an oddball paradigm with auditory sequences differing in numerosity, evoked responses were recorded and mismatch responses were quantified as an indicator for auditory discrimination. Thirty pregnant women with healthy fetuses (last trimester) and 30 healthy term neonates participated. Fourteen adults were included as a control group. Based on measurements eligible for analysis, all adults, all neonates, and 74% of fetuses showed numerical mismatch responses. Numerosity discrimination appears to exist in the last trimester of pregnancy.

Numerical processing has been demonstrated to be closely associated with arithmetic skills, however, our knowledge on the development of the relevant cognitive mechanisms is limited. The present longitudinal study investigated the developmental trajectories of numerical processing in 42 children with age-adequate arithmetic development and 41 children with dyscalculia over a 2-year period from beginning of Grade 2, when children were 7; 6 years old, to beginning of Grade 4. A battery of numerical processing tasks (dot enumeration, non-symbolic and symbolic comparison of one- and two-digit numbers, physical comparison, number line estimation) was given five times during the study (beginning and middle of each school year). Efficiency of numerical processing was a very good indicator of development in numerical processing while within-task effects remained largely constant and showed low long-term stability before middle of Grade 3. Children with dyscalculia showed less efficient numerical processing reflected in specifically prolonged response times. Importantly, they showed consistently larger slopes for dot enumeration in the subitizing range, an untypically large compatibility effect when processing two-digit numbers, and they were consistently less accurate in placing numbers on a number line. Thus, we were able to identify parameters that can be used in future research to characterize numerical processing in typical and dyscalculic development. These parameters can also be helpful for identification of children who struggle in their numerical development.

Background:  The relationship between phoneme awareness, rapid automatized naming (RAN), verbal short-term/working memory (ST/WM) and diagnostic category is investigated in control and dyslexic children, and the extent to which this depends on orthographic complexity., Methods: General cognitive, phonological and literacy skills were tested in 1,138 control and 1,114 dyslexic children speaking six different languages spanning a large range of orthographic complexity (Finnish, Hungarian, German, Dutch, French, English)., Results: Phoneme deletion and RAN were strong concurrent predictors of developmental dyslexia, while verbal ST/WM and general verbal abilities played a comparatively minor role. In logistic regression models, more participants were classified correctly when orthography was more complex. The impact of phoneme deletion and RAN-digits was stronger in complex than in less complex orthographies., Conclusions: Findings are largely consistent with the literature on predictors of dyslexia and literacy skills, while uniquely demonstrating how orthographic complexity exacerbates some symptoms of dyslexia., (© 2012 The Authors. Journal of Child Psychology and Psychiatry © 2012 Association for Child and Adolescent Mental Health.)