Robert Savage

Association of the dopamine transporter (DAT1) 10/10-repeat genotype with ADHD symptoms and response inhibition in a general population sample.

Association between attention-deficit hyperactivity disorder (ADHD) and the 10-repeat allele of the dopamine transporter gene (DAT1) has been reported in independent clinical samples using a categorical clinical definition of ADHD. The present study adopts a quantitative trait loci (QTL) approach to examine the association between DAT1 and a continuous measure of ADHD behaviours in a general-population sample, as well as to explore whether there is an independent association between DAT1 and performance on neuropsychological tests of attention, response inhibition, and working memory. From an epidemiological sample of 872 boys aged 6–11 years, we recruited 58 boys scoring above the 90th percentile for teacher reported ADHD symptoms (SWAN ADHD scale) and 68 boys scoring below 10th percentile for genotyping and neuropsychological testing. A significant association was found between the DAT1 homozygous 10/10-repeat genotype and high-scoring boys (χ2square=4.6, P<0.03; odds ratio=2.4, 95% CI 1.1–5.0). Using hierarchical linear regression, a significant independent association was found between the DAT1 10/10-repeat genotype and measures of selective attention and response inhibition after adjusting for age, IQ, and ADHD symptoms. There was no association between DAT1 and any component of working memory. Furthermore, performance on tasks of selective attention although associated with DAT1 was not associated with SWAN ADHD high scores after controlling for age and IQ. In contrast, impairment on tasks that tapped sustained attention and the central executive component of working memory were found in high-scoring boys after adjusting for age and IQ. The results suggest that DAT1 is a QTL for continuously distributed ADHD behaviours in the general population and the cognitive endophenotype of response inhibition.

Evidence of a highly specific relationship between rapid automatic naming of digits and text reading speed.

This paper explores the specificity of the relationship between rapid automatic naming and reading fluency. Reading accuracy, rate, and fluency was measured among a sample of 67 children, the majority of whom were very poor readers. Regression analyses revealed that phonological processing tasks predicted reading accuracy and comprehension whereas rapid digit (but not picture) naming predicted reading accuracy and rate. After further controlling reading accuracy, digit naming was still a significant predictor of reading rate. This suggests that rapid alphanumeric naming is a highly specific predictor of reading rate and that rapid digit naming and phonological processing are distinct contributors to different aspects of reading in poor readers.

Relationships among rapid digit naming, phonological processing, motor automaticity, and speech perception in poor, average, and good readers and spellers.

In this article, we explore the relationship between rapid automatized naming (RAN) and other cognitive processes among below-average, average, and above-average readers and spellers. Nonsense word reading, phonological awareness, RAN, automaticity of balance, speech perception, and verbal short-term and working memory were measured. Factor analysis revealed a 3-component structure. The first component included phonological processing tasks, RAN, and motor balance. The second component included verbal short-term and working memory tasks. Speech perception loaded strongly as a third component, associated negatively with RAN. The phonological processing tests correlated most strongly with reading ability and uniquely discriminated average from below- and above-average readers in terms of word reading, reading comprehension, and spelling. On word reading, comprehension, and spelling, RAN discriminated only the below-average group from the average performers. Verbal memory, as assessed by word list recall, additionally discriminated the below-average group from the average group on spelling performance. Motor balance and speech perception did not discriminate average from above- or below-average performers. In regression analyses, phonological processing measures predicted word reading and comprehension, and both phonological processing and RAN predicted spelling.

Revisiting the simple view of reading

BACKGROUND Reading component models such as the Simple View of Reading (SVR; Gough & Tunmer, 1986; Hoover & Gough, 1990) provide a concise framework for describing the processes and skills involved when readers comprehend texts. According to the Independent Review of the Teaching of Early Reading (Rose, 2006) strong evidence for the SVR comes from Factor Analysis of datasets on different measures of reading showing dissociation between decoding skills and comprehension. To the best of our knowledge, only two such published studies exist to date. Of these, only one of is in English and this explores children between the age of 7 and 10 years. AIMS To explore the SVR in English-speaking children aged 4 and 6 using Factor Analysis. SAMPLES 116 4-year-olds and 116 6-year-olds in the US; 103 6-year-olds in Canada. METHODS All children were administered a battery of decoding and comprehension related measures. RESULTS Factor Analysis of the diverse measures undertaken independently by two research teams in different countries demonstrated that listening comprehension and decoding measures loaded as distinct factors in both samples of young English-speaking children. CONCLUSIONS The present findings provide important support for the generality and validity of the SVR framework as a model of reading.

Motor skills, automaticity and developmental dyslexia: A review of the research literature

This paper reviews a body of prominent theoriesof automaticity in developmental dyslexia. Thefirst part of the review considers therelationship between dyslexia and rapidautomatic naming and fluency. Additionaltheoretical and empirical advances aresuggested to this already strong research base.In particular, there is a need is forexperimental work elucidating the nature ofnaming speed deficits and providing independentevidence of the automaticity of rapid naming.The second part of the review considersevidence for deficits in motor automaticity indyslexic children. Here, a more mixed patternof results is evident. It is concluded thatthere is currently clearer evidence forlanguage-based than motor-based automaticitydeficits. Future motor automaticity research islikely to require the routine screening of poorreaders for common co-occurring developmentaldifficulties, improved sampling and prospectivelongitudinal studies.

Rapid Serial Naming Is a Unique Predictor of Spelling in Children

Some previous research has shown strong associations between spelling ability and rapid automatic naming (RAN) after controls for phonological processing and nonsense-word reading ability, consistent with the double-deficit hypothesis in reading and spelling. Previous studies did not, however, control for nonsense-word spelling ability before assessing RAN—spelling associations. In this study, 65 children with poor spelling skills but average reasoning ability completed RAN tasks and spelling, reading, and reasoning tasks. Hierarchical regression analyses revealed that, after controls for chronological age, reasoning ability, and spelling of nonsense words, alphanumeric RAN, but not nonalphanumeric RAN, was still a strong predictor of spelling acquisition. Findings are discussed in terms of single- and double-deficit models of spelling and implications for effective teaching.

Bullying risk in children with learning difficulties in inclusive educational settings

This study investigated whether students with learning difficulties (LDs) attending inclusive schools that eschewed segregated “pull out” programs reported more incidents of being bullied than their peers without LDs. Cognitive and self-perception factors associated with reports of peer victimization were also explored. Participants were 13 Grade 5 students with LDs and 14 classmates without LDs, matched on gender. Results showed that students with LDs self-reported significantly more incidents of being bullied than students without LDs. After statistical controls for group differences in receptive vocabulary, differences in bullying were no longer significant. Results suggest first that children with LDs in inclusive schools that eschew pull-out programs may still experience significant bullying. Second, the link between LDs, peer rejection, and victimization may reflect the social impact of language difficulties. Implications for reducing peer victimization in inclusive settings are discussed.

Beyond Phonology What Else Is Needed to Describe the Problems of Below-Average Readers and Spellers?

The difficulties experienced by below-average readers in phonological decoding tasks are well documented. Recent research has suggested that additional deficits in perceptual—motor fluency, handedness, and memory may also exist among below-average readers. To evaluate these claims, average and below-average readers and spellers were compared on a range of phonological processing, verbal short-term and working memory, rapid naming, handedness, and perceptual—motor fluency tasks. Average and below-average readers were sampled in a comparable manner and were also comparable on age, gender, nonverbal ability, socioeconomic status, and ethnicity. Below-average readers and spellers performed lower than average readers and spellers on rhyme detection, pseudoword decoding, and rapid digit (but not picture) naming tasks, but showed no differences in handedness tasks or on a range of other perceptual—motor tasks.

The effects of rime‐ and phoneme‐based teaching delivered by Learning Support Assistants

This paper evaluates three word-level teaching programmes delivered by trained Learning Support Assistants (LSAs) for Year 1 children ‘at risk’ of reading difficulties. Rime-based, phoneme-based, and ‘mixed’ (rime and phoneme-based) interventions were contrasted with controls receiving only the National Literacy Strategy. Phonological onset-rime and phoneme manipulation, spelling, and word and non-word reading were measured before and after the nine-week intervention. High rime neighbourhood (HRn) non-words (e.g. ‘dat’– with many real word rime neighbours) and low rime neighbourhood (LRn) non-words (e.g. ‘tav’ with few real word neighbours) were used to evaluate onset-rime- or grapheme-phoneme-based decoding strategies. Results showed greater phonological onset-rime skills, letter-sound knowledge and non-word reading skills in all LSA-taught intervention groups. There was no difference between the HRn and LRn non-words. The only reliable difference between the intervention groups was an advantage in phoneme blending for the rime-taught group. It was concluded that LSAs can enhance literacy development for 6-year-old poor readers. There appears to be no simple association between rime- or phoneme-based teaching intervention and changes in the size of unit used by children following interventions.

Learning support assistants can deliver effective reading interventions for ‘at-risk’ children

Evidence suggests that phonic interventions delivered by trained researchers improve early reading and spelling. This study sought to explore whether school Learning Support Assistants (LSAs) can also improve performance using these methods. Four groups (each of n = 27) of the poorest reading 6-year-old children in nine schools were screened and selected for this study. LSAs were briefly trained to administer phonic programmes as small group interventions for nine weeks. Rhyme- and phoneme-based programmes were also contrasted with controls receiving the National Literacy Strategy. At post-test, all intervention group children were better decoders, and had better phonological awareness and letter – sound knowledge than controls. The phoneme-based group had better letter – sound knowledge than the other intervention groups. It is concluded that trained Learning Support Assistants can deliver effective early preventive programmes for literacy difficulties.