Publications by authors named "Landerl K"

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.

View Article and Find Full Text PDF
Article Synopsis
  • * A genome-wide association study (GWAS) involving over 13,000 to 33,000 participants revealed significant associations in word reading linked to specific genetic markers, while accounting for 13-26% of the variability in various language-related traits.
  • * The research indicates a shared genetic factor among several language skills and establishes connections to brain structure associated with language processing, emphasizing the role of genetics in understanding human language abilities.
View Article and Find Full Text PDF

Number writing involves transcoding from number words (e.g., "thirty-two") to written digit strings (32) and is an important unique predictor of arithmetic.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

The visual word form area (VWFA) in the left ventral occipito-temporal (vOT) cortex is key to fluent reading in children and adults. Diminished VWFA activation during print processing tasks is a common finding in subjects with severe reading problems. Here, we report fMRI data from a multicentre study with 140 children in primary school (7.

View Article and Find Full Text PDF

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).

View Article and Find Full Text PDF
Article Synopsis
  • Developmental dyslexia (DD) is a genetic learning disorder with a heritability of 40-60%, but much of this genetic basis is still unclear, leading researchers to conduct extensive genetic studies.
  • A genome-wide association study involving 2,274 dyslexia cases and 6,272 controls identified significant relevant genes, including LOC388780 and VEPH1, and estimated SNP-based heritability for DD at around 20-25%.
  • The research found links between dyslexia risk and polygenic scores for various neuropsychiatric disorders, revealing potential shared genetic factors between dyslexia and conditions like ADHD, bipolar disorder, and schizophrenia.
View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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 ( = 73) or below-average ( = 57) achievement in early arithmetic was followed from the end of Grade 1 (mean age: 86.

View Article and Find Full Text PDF

Objective: Reading fluency deficits characteristic for reading disorders (RD; F81.0) have been shown to be strongly associated with slow naming speed (e.g.

View Article and Find Full Text PDF

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).

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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, = 10); (2) children with isolated spelling deficit (ISD, = 17); and (3) typically developing children (TD, = 21).

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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).

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF