Saskia Kohnen

Sight Word and Phonics Training in Children With Dyslexia

The aims of this study were to (a) compare sight word training and phonics training in children with dyslexia, and (b) determine if different orders of sight word and phonics training have different effects on the reading skills of children with dyslexia. One group of children (n = 36) did 8 weeks of phonics training (reading via grapheme–phoneme correspondence rules) and then 8 weeks of sight word training (reading irregular words as a whole), one group did the reverse (n = 36), and one group did phonics and sight word training simultaneously for two 8-week periods (n = 32). We measured the effects of phonics and sight word training on sight word reading (trained irregular word reading accuracy, untrained irregular word reading accuracy), phonics reading (nonword reading accuracy, nonword reading fluency), and general reading (word reading fluency, reading comprehension). Sight word training led to significant gains in sight word reading measures that were larger than gains made from phonics training, phonics training led to statistically significant gains in a phonics reading measure that were larger than gains made from sight word training, and both types of training led to significant gains in general reading that were similar in size. Training phonics before sight words had a slight advantage over the reverse order. We discuss the clinical implications of these findings for improving the treatment and assessment of children with dyslexia.

Assessing spelling skills and strategies: A critique of available resources

In this paper, we discuss a variety of spelling tests that are used to assess developmental spelling difficulties. We differentiate between tests that are valuable tools to monitor spelling development and spelling tests that should be used to further assess children who are not making sufficient progress in the mainstream classroom. We recommend the use of several tests in order to achieve these assessment goals. This paper is a practical guide for clinicians and teachers concerned with the assessment (and treatment) of poor spellers.

Predicting generalization in the training of irregular-word spelling: Treating lexical spelling deficits in a child

This paper presents a single case study investigating the mechanisms underlying generalization of treatment benefits to untrained words in spelling. Brunsdon, Coltheart, and Nickels (2005) observed that untreated words that improved tended to be those whose errors were closest to being correct prior to treatment. These words also tended to be high in written frequency. The present study employed the same treatment techniques as those used by Brunsdon et al. with K.M., a developmental surface dysgraphic. During a first treatment the characteristics of words whose spelling improved without specific training were identified. These characteristics were then used in a second treatment to test whether it was possible to predict generalization. The results showed that treatment generalization to untreated irregular words was best predicted by neighbourhood size and frequency. We suggest that the processes underlying treatment generalization are based on the interaction between the orthographic lexicon and the graphemic buffer. Clinical implications are discussed.

Getting to grips with the heterogeneity of developmental dyslexia

The aim of this study was to better understand the heterogeneity of developmental dyslexia by identifying the most common deficits in the reading systems of children with dyslexia with different poor word reading profiles. We classified the word reading profiles of 138 children with developmental dyslexia using nonword and irregular-word reading tests and then used independent experimental tests to explore the cognitive deficits within their word reading systems. The most common deficit associated with primary sublexical impairment (i.e., poor nonword reading) was poor grapheme–phoneme conversion (GPC) knowledge. The most common deficits associated with primary lexical impairment (i.e., poor irregular-word reading) were an impaired orthographic lexicon plus impaired links between this lexicon and the phonological lexicon and semantic knowledge. Finally, the most common deficits associated with mixed reading impairment (i.e., poor nonword reading and poor irregular-word reading) were poor GPC knowledge, an impaired orthographic lexicon, poor links between this lexicon and the phonological lexicon and semantic knowledge, and poor phonological output. We discuss the implications of these findings for theories of reading and for the diagnosis and treatment of dyslexia.

An Untapped resource : treatment as a tool for revealing the nature of cognitive processes

This paper focuses on the role of treatment in cognitive neuropsychological research, arguing that treatment for cognitive impairments should be viewed as a powerful methodology for developing, evaluating, and extending cognitive theories. We suggest that the key aim of cognitive neuropsychology should be characterized as the use of data from the investigation and treatment of individuals with cognitive disorders to develop, evaluate, and extend theories of normal cognition. To support this assertion, this paper discusses examples of how treatment studies have informed theory. The major methodological tool is generalization logic, both generalization across items and generalization across tasks. However, an alternative is to use case series methodology to test predicted correlations between particular cognitive skills and response to treatment. These methods enable explicit testing of a theory or discrimination between theories, focusing on the nature of cognitive representations, the architecture of the cognitive system, and the acquisition of cognitive skills.

Australian comparison data for the Test of Word Reading Efficiency (TOWRE)

This paper reports provisional Australian comparison data and scoring instructions for the Test of Word Reading Efficiency (TOWRE). The TOWRE is a popular reading fluency test used in reading research, classroom assessment and clinical practice. Approximate ‘norms’ were obtained from children attending four primary schools in New South Wales. Results suggested that the US norms for the TOWRE may overestimate the reading level of Australian children in lower grades and that the performance on the two parallel forms (A and B) of the subtests (Sight Word Efficiency and Phonemic Decoding Efficiency) of the TOWRE did not differ from each other. While no performance differences were found between boys and girls overall, it was noted that the youngest boys outperformed the youngest girls on Form A of the Sight Word Efficiency subtest, and the youngest girls outperformed the youngest boys on Form B of the Sight Word Efficiency subtest. Limitations of the current study are discussed and a brief reference is made to a new (2012) edition of TOWRE (TOWRE-2).

Developmental disorders: what can be learned from cognitive neuropsychology?

The discipline of cognitive neuropsychology has been important for informing theories of cognition and describing the nature of acquired cognitive disorders, but its applicability in a developmental context has been questioned. Here, we revisit this issue, asking whether the cognitive neuropsychological approach can be helpful for exploring the nature and causes of developmental disorders and, if so, how. We outline the key features of the cognitive neuropsychological approach, and then consider how some of the major challenges to this approach from a developmental perspective might be met. In doing so, we distinguish between challenges to the methods of cognitive neuropsychology and those facing its deeper conceptual underpinnings. We conclude that the detailed investigation of patterns of both associations and dissociations, and across both developmental and acquired cases, can assist in describing the cognitive deficits within developmental disorders and in delineating possible causal pathways to their acquisition.

The locus of impairment in English developmental letter position dyslexia

Many children with reading difficulties display phonological deficits and struggle to acquire non-lexical reading skills. However, not all children with reading difficulties have these problems, such as children with selective letter position dyslexia (LPD), who make excessive migration errors (such as reading slime as “smile”). Previous research has explored three possible loci for the deficit – the phonological output buffer, the orthographic input lexicon, and the orthographic-visual analysis stage of reading. While there is compelling evidence against a phonological output buffer and orthographic input lexicon deficit account of English LPD, the evidence in support of an orthographic-visual analysis deficit is currently limited. In this multiple single-case study with three English-speaking children with developmental LPD, we aimed to both replicate and extend previous findings regarding the locus of impairment in English LPD. First, we ruled out a phonological output buffer and an orthographic input lexicon deficit by administering tasks that directly assess phonological processing and lexical guessing. We then went on to directly assess whether or not children with LPD have an orthographic-visual analysis deficit by modifying two tasks that have previously been used to localize processing at this level: a same-different decision task and a non-word reading task. The results from these tasks indicate that LPD is most likely caused by a deficit specific to the coding of letter positions at the orthographic-visual analysis stage of reading. These findings provide further evidence for the heterogeneity of dyslexia and its underlying causes.

Can verbal working memory training improve reading

The aim of the current study was to determine whether poor verbal working memory is associated with poor word reading accuracy because the former causes the latter, or the latter causes the former. To this end, we tested whether (a) verbal working memory training improves poor verbal working memory or poor word reading accuracy, and whether (b) reading training improves poor reading accuracy or verbal working memory in a case series of four children with poor word reading accuracy and verbal working memory. Each child completed 8 weeks of verbal working memory training and 8 weeks of reading training. Verbal working memory training improved verbal working memory in two of the four children, but did not improve their reading accuracy. Similarly, reading training improved word reading accuracy in all children, but did not improve their verbal working memory. These results suggest that the causal links between verbal working memory and reading accuracy may not be as direct as has been assumed.

Assessment of lexical and non-lexical spelling in students in Grades 1–7

The main aim of this study was to develop standardised tests that assess some of the most important spelling skills for children in primary school: sound-letter mappings (non-lexical spelling) and word spelling accuracy (lexical spelling). We present normative comparison data for children in Grades 1–7 as well as measures of validity and reliability for both tests. Another aim of this study was to assess the relative prevalence of spelling difficulties that only affect one skill selectively (only lexical or only non-lexical spelling) or both. We found that throughout Grades 1–7, children were as likely to have selective as they were to have mixed difficulties. This underscores the importance of measuring lexical and non-lexical skills separately. The tests presented in this paper provide teachers and clinicians with the necessary tools to do exactly that.