Hannah M. Nash

Teaching new words to children with poor existing vocabulary knowledge: a controlled evaluation of the definition and context methods

BACKGROUNDnChildren who have poor vocabulary knowledge are at risk of wider language weaknesses and reading comprehension difficulties, which will impact upon their educational achievement. The central question addressed in this paper is how best to teach new vocabulary items to these children.nnnAIMSnTo investigate the effects of two different methods of teaching vocabulary on both vocabulary knowledge and reading comprehension.nnnMETHODS & PROCEDURESnTwenty-four children (aged 7-8 years) with poor existing vocabulary knowledge took part in an intervention study. Half the children were taught new vocabulary items using definitions; the other half were taught a strategy for deriving meanings from written context. Tests of vocabulary knowledge were given before teaching, immediately after teaching and 3 months later.nnnOUTCOMES & RESULTSnImmediately after teaching, both groups had improved equivalently in vocabulary knowledge for the taught words. However, 3 months later, the context group showed significantly better expressive vocabulary knowledge. The context group went on to show significantly better comprehension of text containing a number of the taught words and demonstrated that they could use the newly acquired strategy independently to derive meanings from written context.nnnCONCLUSIONSnThe context method developed is effective in increasing vocabulary knowledge and improving reading comprehension in children with poor existing vocabulary knowledge, and this is therefore recommended for use with children who require extra help developing vocabulary and comprehension skills.

Developmental dyslexia: Predicting individual risk

Background Causal theories of dyslexia suggest that it is a heritable disorder, which is the outcome of multiple risk factors. However, whether early screening for dyslexia is viable is not yet known. Methods The study followed children at high risk of dyslexia from preschool through the early primary years assessing them from age 3 years and 6 months (T1) at approximately annual intervals on tasks tapping cognitive, language, and executive-motor skills. The children were recruited to three groups: children at family risk of dyslexia, children with concerns regarding speech, and language development at 3;06 years and controls considered to be typically developing. At 8 years, children were classified as ‘dyslexic’ or not. Logistic regression models were used to predict the individual risk of dyslexia and to investigate how risk factors accumulate to predict poor literacy outcomes. Results Family-risk status was a stronger predictor of dyslexia at 8 years than low language in preschool. Additional predictors in the preschool years include letter knowledge, phonological awareness, rapid automatized naming, and executive skills. At the time of school entry, language skills become significant predictors, and motor skills add a small but significant increase to the prediction probability. We present classification accuracy using different probability cutoffs for logistic regression models and ROC curves to highlight the accumulation of risk factors at the individual level. Conclusions Dyslexia is the outcome of multiple risk factors and children with language difficulties at school entry are at high risk. Family history of dyslexia is a predictor of literacy outcome from the preschool years. However, screening does not reach an acceptable clinical level until close to school entry when letter knowledge, phonological awareness, and RAN, rather than family risk, together provide good sensitivity and specificity as a screening battery.

Semantic and phonological fluency in children with Down syndrome : Atypical organization of language or less efficient retrieval strategies?

In this study the verbal fluency procedure was used to investigate the organization of semantic and phonological representations in children with Down syndrome (DS) and typically developing children, matched pairwise for receptive vocabulary age. Productivity was found to be significantly reduced in the DS group in both the semantic and the phonological tasks. However, group differences in the number of clusters as opposed to cluster size suggest that this may reflect less efficient retrieval strategies rather than differences in the organization of linguistic representations. Together the findings point to executive deficits in Down syndrome rather than deviant language processes.

Preschool language profiles of children at family risk of dyslexia: continuities with specific language impairment.

BACKGROUNDnChildren at family risk of dyslexia have been reported to show phonological deficits as well as broader language delays in the preschool years.nnnMETHODnThe preschool language skills of 112 children at family risk of dyslexia (FR) at ages 3½ and 4½ were compared with those of children with SLI and typically developing (TD) controls.nnnRESULTSnChildren at FR showed two different profiles: one third of the group resembled the children with SLI and scored poorly across multiple domains of language including phonology. As a group, the remaining children had difficulties on tasks tapping phonological skills at T1 and T2. At the individual level, we confirmed that some FR children had both phonological and broader oral language difficulties (compared with TD controls), some had only phonological difficulties and some appeared to be developing typically.nnnCONCLUSIONSnWe have highlighted the early overlap between family risk of dyslexia and SLI. A family history of dyslexia carries an increased risk for SLI and the two disorders both show an increased incidence of phonological deficits which appear to a proximal risk factor for developing a reading impairment.

Validity of a protocol for adult self-report of dyslexia and related difficulties

Background There is an increased prevalence of reading and related difficulties in children of dyslexic parents. In order to understand the causes of these difficulties, it is important to quantify the risk factors passed from parents to their offspring. Method 417 adults completed a protocol comprising a 15-item questionnaire rating reading and related skills and a scale assessing ADHD symptoms; 344 completed reading, nonword reading and spelling tests. Results A confirmatory factor analysis with four factors (Reading, Word Finding, Attention and Hyperactivity) provided a reasonable fit to the data. The Reading Factor showed robust correlations with measured literacy skills. Adults who reported as dyslexic, or rated their reading difficulties as more severe, gained lower scores on objective measures of literacy skills. Although the sensitivity of the new scale was acceptable, it tended to miss some cases of low literacy. Conclusions Self-report scales of reading and of attention difficulties are useful for identifying adults with reading and attention difficulties which may confer risks on their children of related problems. It is important for research following children at family risk of dyslexia to be aware of these effects. Copyright

The Foundations of Literacy Development in Children at Familial Risk of Dyslexia

The development of reading skills is underpinned by oral language abilities: Phonological skills appear to have a causal influence on the development of early word-level literacy skills, and reading-comprehension ability depends, in addition to word-level literacy skills, on broader (semantic and syntactic) language skills. Here, we report a longitudinal study of children at familial risk of dyslexia, children with preschool language difficulties, and typically developing control children. Preschool measures of oral language predicted phoneme awareness and grapheme-phoneme knowledge just before school entry, which in turn predicted word-level literacy skills shortly after school entry. Reading comprehension at 8½ years was predicted by word-level literacy skills at 5½ years and by language skills at 3½ years. These patterns of predictive relationships were similar in both typically developing children and those at risk of literacy difficulties. Our findings underline the importance of oral language skills for the development of both word-level literacy and reading comprehension.

Language Profiles and Literacy Outcomes of Children with Resolving, Emerging, or Persisting Language Impairments.

Background Children with language impairment (LI) show heterogeneity in development. We tracked children from pre‐school to middle childhood to characterize three developmental trajectories: resolving, persisting and emerging LI. Methods We analyzed data from children identified as having preschool LI, or being at family risk of dyslexia, together with typically developing controls at three time points: t1 (age 3;09), t3 (5;08) and t5 (8;01). Language measures are reported at t1, t3 and t5, and literacy abilities at t3 and t5. A research diagnosis of LI (irrespective of recruitment group) was validated at t1 by a composite language score derived from measures of receptive and expressive grammar and vocabulary; a score falling 1SD below the mean of the typical language group on comparable measures at t3 and t5 was used to determine whether a child had LI at later time points and then to classify LIs as resolving, persisting or emerging. Results Persisting preschool LIs were more severe and pervasive than resolving LIs. Language and literacy outcomes were relatively poor for those with persisting LI, and relatively good for those with resolving LI. A significant proportion of children with average language abilities in preschool had LIs that emerged in middle childhood – a high proportion of these children were at family risk of dyslexia. There were more boys in the persisting and resolving LI groups. Children with early LIs which resolved by the start of formal literacy instruction tended to have good literacy outcomes; children with late‐emerging difficulties that persisted developed reading difficulties. Conclusions Children with late‐emerging LI are relatively common and are hard to detect in the preschool years. Our findings show that children whose LIs persist to the point of formal literacy instruction frequently experience reading difficulties.

The growth of reading skills in children with Down Syndrome.

There appears to be a close and probably causal relationship between early variations in phoneme skills and later reading skills in typically developing children, though the pattern in children with Down Syndrome is less clear. We present the results of a 2-year longitudinal study of 49 children with Down Syndrome (DS) and 61 typically developing (TD) control children with similar initial levels of reading skill. Phoneme awareness and vocabulary were strong concurrent predictors of initial levels of reading skill in both groups. However, longitudinally phoneme awareness was a predictor of the growth of reading skills in TD children but not in children with DS. There was a very high degree of longitudinal stability in reading skills in children with DS, and initial levels of reading skills seemed to be highly constrained by general language skills, as indexed by vocabulary knowledge, in this population. We conclude that reading development in children with DS shows similarities and differences to the pattern observed in TD children and that phoneme awareness appears to be a less powerful influence on the development of reading skills in children with DS.

The Development of Executive Function and Language Skills in the Early School Years.

Background The developmental relationships between executive functions (EF) and early language skills are unclear. This study explores the longitudinal relationships between childrens early EF and language skills in a sample of children with a wide range of language abilities including children at risk of dyslexia. In addition, we investigated whether these skills independently predict childrens attention/behaviour skills. Method Data are presented from 243 children at four time points. Children were selected for being at risk of reading difficulties either because of a family history of dyslexia (FR; N = 90) or because of concerns regarding their language development (LI; N = 79) or as typically developing controls (TD; N = 74). The children completed tasks to assess their executive function and language skills at ages 4, 5 and 6 years. At 6 (T4) and 7 years (T5) parents and teachers rated the childrens attention/behaviour skills. Results There was a strong concurrent relationship between language and EF at each assessment. Longitudinal analyses indicated a considerable degree of stability in childrens language and EF skills: the influence of language on later EF skills (and vice versa) was weak and not significant in the current sample. Childrens EF, but not language, skills at T3 predicted attention/behaviour ratings at T4/T5. Conclusions There is a strong concurrent association between language and EF skills during the preschool and early school years, when children with language impairment show persistent EF deficits. Latent variables measuring language and EF show high longitudinal stability with little evidence of significant or strong reciprocal influences between these constructs. EF, but not language, skills predict later ratings of childrens attention and behaviour.

Comorbidities in preschool children at family risk of dyslexia

BACKGROUNDnComorbidity among developmental disorders such as dyslexia, language impairment, attention deficit/hyperactivity disorder and developmental coordination disorder is common. This study explores comorbid weaknesses in preschool children at family risk of dyslexia with and without language impairment and considers the role that comorbidity plays in determining childrens outcomes.nnnMETHODnThe preschool attention, executive function and motor skills of 112 children at family risk for dyslexia, 29 of whom also met criteria for language impairment, were assessed at ages 3½ and 4½ years. The performance of these children was compared to the performance of children with language impairment and typically developing controls.nnnRESULTSnWeaknesses in attention, executive function and motor skills were associated with language impairment rather than family risk status. Individual differences in language and executive function are strongly related during the preschool period, and preschool motor skills predicted unique variance (4%) in early reading skills over and above childrens language ability.nnnCONCLUSIONnComorbidity between developmental disorders can be observed in the preschool years: children with language impairment have significant and persistent weaknesses in motor skills and executive function compared to those without language impairment. Childrens early language and motor skills are predictors of childrens later reading skills.