Disentangling dyslexia from typical L2-learning in emergent literacy.

The present paper assessed how dyslexia can be identified in school children with another language than their first language. Participants were school children with Norwegian as their second language (L2), and two groups of children with Norwegian as their first language (L1): a control group (L1-Con), and a dyslexia group (L1-Dys). All were 2nd and 3rd graders who had attended Norwegian schools from 1st grade on. None of the individuals in L1-Con or the L2 group were identified with any learning disability. However, slow literacy progress was seen in some L2-children. The children were tested individually within the symptomatic and cognitive levels. Results were analysed in two steps: (1) group comparisons; (2) L2 individual profiles and tentative L2 subgrouping. An unexpected L2 profile showed language scores below norm, coupled with some scores within and some scores above norm within the cognitive domain. Case assessment of the L2 group resulted in three subgroups: one comparable to L1-Con, one comparable to L1-Dys, and one with a result in between these two groups. Low linguistic scores cannot be considered valid markers of dyslexia in L2. Within the cognitive domain, a variety of low scores can indicate dyslexia, while high scores can be compensatory.

Kindergarten screening tools filled out by parents and teachers targeting dyslexia. Predictions and developmental trajectories from age 5 to age 15 years.

The concept of early 'efforts' has led to discussions for and against introducing language assessment for all kindergarten children. Evidence-based kindergarten screening tools completed by close caregivers could solve this controversy as the children themselves would only be indirectly involved. The aim of this study was to see whether the scores of such early screening tools aiming at developmental dyslexia could predict school marks of literacy competence 10 years later, and to see whether these screening tools would reveal different dyslexia trajectories. The study is part of the Bergen Longitudinal Dyslexia Study, and the results from individual testing are reported elsewhere. Here, the caregivers' views isolated from the rest of the study are focused. Three tools were used: the RI-5, a questionnaire assessing the risk of dyslexia; the TRAS, a non-standardized observation tool of children's communication skills; and the CCC-2, a questionnaire assessing Developmental Language Disorders. Screening was performed at age 5 (TP1), age 11, (TP2) and age 15 (TP3). At TP2, when dyslexia was identified, 13 children formed the dyslexia group, and the rest formed the control group. At TP3, the RI-5 and CCC-2 turned out to be predictive of literacy competence as measured by school marks. Developmental trajectories were seen through the regroupings and scorings into a persistent group, a late onset group and a resolving group. Evidence-based preschool screening tools filled out by close caregivers offer valid information on later literacy developmental trajectories.

Auditive training effects from a dichotic listening app in children with dyslexia.

Dichotic listening (DL) taps information on the brain's language laterality, processing, and attention. Research has shown that DL responses in dyslexia deviate from the typical pattern. Here, effects of DL training and its correspondence to rapid naming (RAN) and digit span (DS) in typical children and children with dyslexia were assessed. Three groups of third graders participated: two training groups, control training (CT) and dyslexia training (DT), and a control group that received no training (control no training, CnT). All took part in testing pretraining and posttraining. DL measures were on laterality, response scores, and attention. The three groups showed different response patterns: minor changes in CnT, change in all measures in CT, and some changes in DT. RAN and DS scores correlated significantly with some of the DL measures, especially with the attention scores. Our findings support arguments that brain architecture for language in dyslexia is lateralised in the same way as in children without dyslexia. However, the ability to modulate attention during DL is weaker in dyslexia than in typically developing children. A training-induced normalisation of lateralisation was observed in free recall in the dyslexia group, which suggests that DL training may be a promising intervention approach.

Reading in dyslexia across literacy development: A longitudinal study of effective connectivity.

Dyslexia is a literacy disorder affecting the efficient acquisition of reading and writing skills. The disorder is neurobiological in origin. Due to its developmental nature, longitudinal studies of dyslexia are of essence. They are, however, relatively scarce. The present study took a longitudinal approach to cortical connectivity of brain imaging data in reading tasks in children with dyslexia and children with typical reading development. The participants were followed with repeated measurements through Pre-literacy (6 years old), Emergent Literacy (8 years old) and Literacy (12 years old) stages, using Dynamic Causal Modelling (DCM) when analysing functional magnetic resonance imaging (fMRI) data. Even though there are a few longitudinal studies on effective connectivity in typical reading, to our knowledge, no studies have previously investigated these issues in relation to dyslexia. We set up a model of a brain reading network involving five cortical regions (inferior frontal gyrus, precentral gyrus, superior temporal gyrus, inferior parietal lobule, and occipito-temporal cortex). Using DCM, connectivity measures were calculated for each connection in the model. These measures were further analysed using factorial ANOVA. The results showed that the difference between groups centred on connections going to and from the inferior frontal gyrus (two connections) and the occipito-temporal cortex (three connections). For all five connections, the typical group showed stable or decreasing connectivity measures. The dyslexia group, on the other hand, showed a marked up-regulation (occipito-temporal connections) or down-regulation (inferior frontal gyrus connections) from 6 years to 8 years, followed by normalization from 8 years to 12 years. We interpret this as a delay in the dyslexia group in developing into the Pre-literacy and Emergent literacy stages. This delay could possibly be detrimental to literacy development. By age 12, there was no statistically significant difference in connectivity between the groups, but differences in literacy skills were still present, and were in fact larger than when measured at younger ages.

Neurocognitive Development and Predictors of L1 and L2 Literacy Skills in Dyslexia: A Longitudinal Study of Children 5-11 Years Old.

The aim of this study was to find valid neurocognitive precursors of literacy development in first language (L1, Norwegian) and second language (L2, English) in a group of children during their Pre-literacy, Emergent Literacy and Literacy stages, by comparing children with dyslexia and a typical group. Children who were 5 years old at project start were followed until the age of 11, when dyslexia was identified and data could be analysed in retrospect. The children's neurocognitive pattern changed both by literacy stage and domain. Visuo-spatial recall and RAN appeared as early precursors of L1 literacy, while phonological awareness appeared as early precursor of L2 English. Verbal long term memory was associated with both L1 and L2 skills in the Literacy stage. Significant group differences seen in the Pre-literacy and Emergent literacy stages decreased in the Literacy stage. The developmental variations by stage and domain may explain some of the inconsistencies seen in dyslexia research. Early identification and training are essential to avoid academic failure, and our data show that visuo-spatial memory and RAN could be suitable early markers in transparent orthographies like Norwegian. Phonological awareness was here seen as an early precursor of L2 English, but not of L1 Norwegian.

Neuroanatomical precursors of dyslexia identified from pre-reading through to age 11.

Developmental dyslexia is a common reading disorder that negatively impacts an individual's ability to achieve literacy. Although the brain network involved in reading and its dysfunction in dyslexia has been well studied, it is unknown whether dyslexia is caused by structural abnormalities in the reading network itself or in the lower-level networks that provide input to the reading network. In this study, we acquired structural magnetic resonance imaging scans longitudinally from 27 Norwegian children from before formal literacy training began until after dyslexia was diagnosed. Thus, we were able to determine that the primary neuroanatomical abnormalities that precede dyslexia are not in the reading network itself, but rather in lower-level areas responsible for auditory and visual processing and core executive functions. Abnormalities in the reading network itself were only observed at age 11, after children had learned how to read. The findings suggest that abnormalities in the reading network are the consequence of having different reading experiences, rather than dyslexia per se, whereas the neuroanatomical precursors are predominantly in primary sensory cortices.

Brain Laterality in Dyslexia Seen during Literacy Development and Early Training.

During the period in which children learn to read and write, a gradual shift from right to left hemisphere dominance for language is typically seen. However, in children with dyslexia, a deviant pattern is described in the literature. As part of a larger longitudinal study (The Bergen Longitudinal Dyslexia Study), the present study aimed to assess this development from an early age before children learn to read and write. Dichotic listening (DL), which is a non-invasive test, was used to assess the development of brain laterality in a Typical group and a Dyslexia group. The participants received yearly sessions of evidence-based literacy training at ages 5 to 7. The Typical group showed increasing ear scores and a shift from no ear advantage in the Pre-literacy stage (age 6), indicative of no hemisphere dominance, to a right ear advantage, indicative of a left hemisphere dominance, in the Emergent literacy stage (age 8) and the Literacy stage (age 11). The Dyslexia group showed a different pattern, with a significant right ear advantage at age 6, indicative of a right hemisphere dominance, and increasing ear scores at ages 8 and 11; however, no ear dominance was observed in the Literacy stage. The results point to an effect of relevant, evidence-based training affecting both right and left hemispheres in dyslexia, which should form a basis for further research.

Writing in dyslexia: product and process.

Research on dyslexia has largely centred on reading. The aim of this study was to assess the writing of 13 children with and 28 without dyslexia at age 11 years. A programme for keystroke logging was used to allow recording of typing activity as the children performed a sentence dictation task. Five sentences were read aloud twice each. The task was to type the sentence as correctly as possible, with no time constraints. The data were analysed from a product (spelling, grammar and semantics) and process (transcription fluency and revisions) perspective, using repeated measures ANOVA and t-tests to investigate group differences. Furthermore, the data were correlated with measures of rapid automatic naming and working memory. Results showed that the group with dyslexia revised their texts as much as the typical group, but they used more time, and the result was poorer. Moreover, rapid automatic naming correlated with transcription fluency, and working memory correlated with the number of semantic errors. This shows that dyslexia is generally not an issue of effort and that cognitive skills that are known to be important for reading also affect writing.

Structural and functional reorganization of the corpus callosum between the age of 6 and 8 years.

The establishment of an efficient exchange of information between the cerebral hemispheres is of crucial importance in the developing functionally lateralized brain. The corpus callosum, the major connection between the cerebral hemispheres, grows constantly throughout childhood and adolescence. However, behavioral studies suggest the existence of a critical time period for callosal functional development starting around the age of 6 years. In the present longitudinal study, examining a cohort of 20 children at the age of 6 and 8 years, we assessed the relationship between structural and functional callosal development during this time period. The structural development was quantified by calculating the increase in callosal thickness using a shape-based computational analysis of the mid-sagittal corpus callosum as obtained with magnetic resonance imaging. The functional development was assessed with a speech discrimination task based on the dichotic presentation of consonant-vowel syllables. The statistical analysis revealed that children whose callosal isthmus increased in thickness over the course of 2 years showed a decrease in interhemispheric information transfer. However, children exhibiting a decrease in isthmus thickness revealed an increase in information transfer. These results might indicate a refinement process of the callosal connections to optimize the neuronal communication between the developing cerebral hemispheres.

Trends in Dyslexia Research during the Period 1950 to 2020-Theories, Definitions, and Publications.

INTRODUCTION: The focus of the present paper is on (1) how dyslexia research and hence definitions have developed during the period 1950-2020 and includes (2) a database search of scientific publications on dyslexia during the same period. The focus is on the definitions of dyslexia and the organization of the network search based on the causal four-level model by Morton and Frith. METHOD: (1) The definitions are presented in accordance with a historic review of dyslexia research from 1950 to 2020 and based on (2) Google Scholar counts of publications on dyslexia, on defining dyslexia, on dyslexia at the four levels (symptomatic, cognitive, biological, environmental), and by areas (sensorimotor, comorbidity). Finally, a percentage calculation shows the relative development within each level and area by decennium (1950-1960, 1960-1970, 1970-1980, 1990-2000, 2002-2010, 2010-2020). RESULTS: (1) Of the seven definitions presented, only the definition by the BDA 2007 included the four levels of the causal model. (2) The number of publications increased substantially over the period. However, relatively few publications have defined dyslexia. An increase in publications from 1950 to 2020 was seen across the four levels and two areas-however, with an alteration in the thematic focus over this time span. SUMMARY: Defining dyslexia has still not reached a consensus. This uncertainty may explain why only one of the seven definitions proved satisfactory according to the four-level model. Along with the general increase in research, publications on dyslexia have increased accordingly during the period 1950 to 2020. Although the symptomatic level has played a dominant role over the whole period, thematic shifts have been seen over these 70 years. In particular, a substantial thematic shift was seen by the turn of the millennium. There has been a relative increase in the focus on literacy at the symptomatic level, on phonological awareness at the cognitive level, in gender at the biological level, and second language learning as comorbidities. However, increases in counts are not alone a valid indication of scientific progress. In particular, the lack of definitional criteria as a basis for participant and method selection should attract much more focus in future studies. The present study underlines the multifactorial nature of dyslexia, as evidenced by a substantial increase in the number of publications on the subject. It is a challenge for future research to continuously use and possibly redefine dyslexia definitions in line with such standards.

Predicting dyslexia at age 11 from a risk index questionnaire at age 5.

This study focused on predicting dyslexia in children ahead of formal literacy training. Because dyslexia is a constitutional impairment, risk factors should be seen in preschool. It was hypothesized that data gathered at age 5 using questions targeting the dyslexia endophenotype should be reliable and valid predictors of dyslexia at age 11. A questionnaire was given to caretakers of 120 5-year-old children, and a risk index score was calculated based on questions regarding health, laterality, motor skills, language, special needs education and heredity. An at-risk group (n = 25) and matched controls (n = 24) were followed until age 11, when a similar questionnaire and literacy tests were administered to the children who participated in the follow-up study (22 at risk and 20 control). Half of the at-risk children and two of the control children at age 5 were identified as having dyslexia at age 11 (8 girls and 5 boys). It is concluded that it is possible to identify children at the age of 5 who will have dyslexia at the age of 11 through a questionnaire approach.

Emotional and behavioural needs in children with specific language impairment and in children with autism spectrum disorder: The importance of pragmatic language impairment.

BACKGROUND: Language problems may negatively affect children's behaviour and have detrimental effects on the development of peer-relations. AIMS: We investigated and compared emotional and behavioural profiles in children with SLI and in children with ASD aged 6-15 years and explored to what extent pragmatic language problems contributed to the emotional and behavioural needs (EBN) in these clinical groups. METHODS AND PROCEDURES: The ASD group consisted of 23 children (19 boys; 4 girls) and the SLI group consisted of 20 children (18 boys; 2 girls). In order to assess EBN and language abilities, the Strength and Difficulties Questionnaire (SDQ) and the Children's Communication Checklist -2 (CCC-2) were filled out by parents. OUTCOMES AND RESULTS: Our main findings were that although EBN was common in both groups; the children in the ASD group were significantly impaired relative to the children in the SLI group. However, in both groups pragmatic language problems were found to be significantly associated with EBN. IMPLICATIONS: A comprehensive assessment of EBN as well as pragmatic language abilities should be an integral part of the assessment procedure. Considering the substantial influence of pragmatic language abilities on social function and in resolving interpersonal conflicts with peers further development of therapy plans and interventions targeting pragmatics is strongly needed.

The dynamics of narrative writing in primary grade children: writing process factors predict story quality.

In this study of third grade school children, we investigated the association between writing process measures recorded with key stroke logging and the final written product. Moreover, we examined the cognitive predictors of writing process and product measures. Analyses of key strokes showed that while most children spontaneously made local online revisions while writing, few revised previously written text. Children with good reading and spelling abilities made more online revisions than their peers. Two process factors, transcription fluency and online revision activity, contributed to explaining variance in narrative macrostructural quality and story length. As for cognitive predictors, spelling was the only factor that gave a unique contribution to explaining variance in writing process factors. Better spelling was associated with more revisions and faster transcription. The results show that developing writers' ability to make online revisions in creative writing tasks is related to both the quality of the final written product and to individual literacy skills. More generally, the findings indicate that investigations of the dynamics of the writing process may provide insights into the factors that contribute to creative writing during early stages of literacy.

Language Impairments in Children With ADHD and in Children With Reading Disorder.

OBJECTIVE: The objective of this study was to investigate language impairments (LI) in a nonclinical sample of children with ADHD, reading disorder (RD), and ADHD + RD, and to explore whether these groups could be differentiated from each other and a control group regarding different aspects of language. METHOD: The groups were derived from a population-based sample of 5,672 children, 7 to 9 years. Language problems and the groups were defined from parent/teacher reports. RESULTS: LI was identified in the majority within the ADHD + RD group and in >40% of the ADHD and RD group. More phonological and expressive language problems were seen in the RD than the ADHD group, while receptive language problems were more prominent in ADHD. More pragmatic problems were identified in the ADHD group. CONCLUSION: The present results support findings from clinical samples pointing to a considerable rate of LI both in children with ADHD and in children with RD.

Visual-sequential and visuo-spatial skills in dyslexia: variations according to language comprehension and mathematics skills.

This study focused on visual-sequential and visuo-spatial functions in a group of 39 heavily dyslexic children, compared to a Control group. Mean age was 12.72 (SD 1.71). The dyslexia group was divided into three subgroups by language comprehension and mathematics skills. Only on a visual-sequential task was no difference seen between the groups. The main differences occurred between the two dyslexic subgroups with no language comprehension impairment, but with varying mathematics skills. Whereas the subgroup with good mathematics skills scored within the upper ranges, the mathematics-impaired subgroup showed significantly lower scores. The third dyslexic subgroup, with both language comprehension and mathematics impairments, performed within the norm. The study indicates a dissociation between language comprehension and visuo-spatial skills in dyslexia, which has implications for how variations in dyslexia should be understood. The results also show that the visuo-spatial impairments seen in one of the dyslexia subgroups lead to two ways of understanding mathematics impairment when it co-occurs with dyslexia: (1) as a visuo-spatial problem; (2) as a linguistic problem. These distinctions should imply different intervention strategies in dyslexia.

The role of dichotic listening performance and tasks of executive functions in reading impairment: a discriminant function analysis.

This study focused on the role of dichotic listening performance for the identification of reading impaired subtypes. Dichotic listening (DL), using verbal stimuli, has shown to be a valid measure of language lateralization. Usually, lateralization is estimated from the proportion of right ear over left ear accuracy during a free recall test procedure. However, it has been suggested that a more accurate estimate of laterality can be obtained by using a directed attention procedure. A sample of 43 reading disabled children of whom 18 showed signs of impaired language comprehension skills and 25 without language comprehension impairments, were compared to 20 age, and gender, matched controls on dichotic listening performance in both an unbiased free recall task and in a directed attention task using consonant-vowel syllables as dichotic stimuli. A laterality index was calculated for left and right ear stimuli reported during both the free recall condition and the attended ear-scores for the two directed attention conditions. Although both DL procedures yielded significant group differences, with a lower laterality score for the reading disabled compared to the controls, there was no main effect of DL-procedure or group x procedure interaction. Taken alone, DL performance could correctly classify 42% of the reading impaired samples, but together with other measures of executive functions, discriminant function analyses yielded 90.74% accuracy in classifying reading impaired children. The result indicates that DL together with tests of executive functions are valuable tools for assessment of reading impaired subjects.

Attentional functions in speech fluency disorders.

This study focused on attentional functions in fluency disorders. Nine persons who stuttered, eight persons who cluttered, and nine fluent controls, executed a set of attention tasks while psychophysiological indices of activation (heart rate variability and skin conductance) were recorded. The results indicated that the stutter group had a significantly longer response time on the Posner Test of Covert Attention Shifts than the other two groups, and the effect was most obvious when the target appeared in the right visual field. There were no significant differences between groups in the physiological activation as measured by heart rate, skin conductance and heart rate variability. The present results support the hypotheses that stuttering may be associated with impaired skills to focus attention, while cluttering did not seem to be associated with impaired focused attentional skills. However, the sample available within the study period was limited, and due to small samples care should be taken before making firm conclusions.

Language profiles and mental health problems in children with specific language impairment and children with ADHD.

OBJECTIVE: This study aimed to explore whether children with specific language impairment (SLI) and children with ADHD can be differentiated from each other in terms of their language profiles, and also to investigate whether these two clinical groups differ regarding mental health problems. METHOD: A total of 59 children in the age range 6 to 12 years participated in the study. The parents completed the Children's Communication Checklist-Second Edition and the Strengths and Difficulties Questionnaire. RESULTS: Communication impairments were as prominent in the ADHD group as in the SLI group; however, the groups were separable from each other in terms of their language profiles. Furthermore, the ADHD group experienced significantly more mental health problems compared with the SLI group. CONCLUSION: Language should be assessed in children with ADHD and instruments sensitive to ADHD should be included when assessing children with SLI. Mental health should be an area of concern to be addressed in both groups.