Reading acquisition and developmental dyslexia

  • Sprenger-Charolles Liliane
  • Colé Pascale
  • Serniclaes Willy

OUV

Reviewed by Susanne Borgwaldt, Written Language & Literacy, 13(2), 2010, 276-279 Reading Acquisition and Developmental Dyslexia by Sprenger-Charolles, Colé and Serniclaes presents an introduction into both literacy acquisition and the processes underlying skilled (adult) reading, focusing on single word recognition. Additionally, manifestations and possible causes of developmental dyslexia are discussed. /e authors focus on how this plays out in alphabetic orthographies, but fortunately they do not limit their approach to studies dealing with the English orthography. Instead, they present not only cross-linguistic data, but also both cross-sectional and longitudinal studies, concentrating on research conducted with English-, French-, German-, and Spanish-speaking participants. In the field of literacy research, this broad and balanced approach is admirable, as the research area in general is dominated by studies about English (e.g. Share 2008), often resulting in attempts to generalize from reading in English to reading in alphabetic orthographies in general, without taking into account how reading processes are influenced by language- and orthography-specific features. The book is divided into five chapters, each ending with a brief summary. It comprises 196 pages of text, followed by a list of references, an author index, and a subject index. The first chapter provides a basic overview about visual word recognition in skilled readers. /e authors describe psycholinguistic research on the effects of congruous and incongruous contexts on word identification, the Stroop paradigm, word-picture interference effects, and masked priming studies that are employed to tap into the time-course of orthographic, phonological, and semantic processing during word recognition. The chapter also briefly summarizes data from neuro-imaging studies that aim at localizing brain areas involved in reading. The second chapter, entitled 'Reading acquisition in deep and shallow orthographies', focuses on literacy development in beginning readers. First, the authors describe basic features of alphabetic orthographies, briefly introducing the different units at which words can be analyzed such as letters, graphemes, subsyllabic units like onset and rhyme, syllables, and morphemes. /ese units vary in grain size and, at least in some languages, also in the consistency of mapping from orthography to phonology. The authors claim that all units are simultaneously available to the reader, who might read a frequent and/or irregular word without splitting it up into smaller units (on the lexical route), but might read unknown words by converting smaller orthographical units into phonological units (on the sublexical route). Next, the authors discuss characteristics of the English, French, German, and Spanish orthographies in detail. It might have been better to describe these four orthographies first and then to proceed to the general principles underlying alphabetic orthographies. This would probably have aided the reader in relating characteristics of a specifc orthography to the theoretical notions mentioned above. The next section discusses the time course of literacy acquisition. The authors present cross-sectional and longitudinal studies with beginning readers (Grade 1 to 4) and show that children learning to read in English, a very deep orthography with highly inconsistent mappings between orthography and phonology, lag behind children learning to read in more shallow orthographies that display more consistent mappings. /is lag is largest in Grade 1, but gradually decreases through Grades 2, 3, and 4, suggesting that the inhibitory influence of a deep orthography on literacy development will eventually be overcome among typically developing children. The comparative studies in this chapter also indicate qualitative differences in developing readers, with English-speaking children relying more on lexical processing or on larger units such as the rhyme, and beginning readers in shallow orthographies predominantly relying on small units like graphemes. The authors then move on to discuss research on the reading of polysyllabic words. They argue that syllable-based processing may play an important role in reading polysyllabic words for Spanish- or French-speaking developing readers, as these two languages have clear syllable boundaries and do not show the ambisyllabicity found in languages like English or German. Research on the reading of morphologically complex words, such as inflected word forms (reading), derivations (reader) or compounds (proofread), shows that only relatively advanced readers perform morphological processing, i.e. an analysis of complex words into their (often, but not always) meaningful sub-parts, a process that seems to facilitate understanding. In contrast to the relative lack of studies investigating the impact of morphological awareness on reading skills, the relationship between reading skills and phonological awareness (a relatively conscious understanding of phonological units like syllables, subsyllabic units like onset and rhyme, and phonemes) has been studied in great depth. Phonological awareness comprises several subtypes, e.g. phonemic awareness, syllabic awareness, or rhyme awareness. But the most important factor in successfully learning to read seems to be the development of phonemic awareness, which helps beginning readers to understand the general architecture of alphabetic orthographies. The next two chapters (Chapters 3 and 4) discuss manifestations of developmental dyslexia and possible origins of dyslexic reading deficits. Chapter 3 starts by re-examining various definitions of developmental dyslexia and then focuses on the methodological issues in such research, describing typical research designs, issues pertaining to the choice of control groups (matching chronological age, or reading level) and limitations of various approaches. Armed with this information, the authors first present research in English, split up according to research design into group studies, single case studies, and multiple case studies. After discussing the outcomes of the research on English, they present research conducted in other languages, to assess the reliability of the effects found with English-speaking dyslexics. The discussion centers on the existence of subtypes of dyslexia, i.e. surface dyslexics vs. phonological dyslexics, lexicality and regularity effects, the relation between accuracy and speed in reading, and compensatory strategies. The authors conclude that the cross-linguistic research reported so far is more compatible with the assumption that a specific phonological processing deficit characterizes reading performance in developmental dyslexia, negatively affecting sublexical reading skills, than with the idea that clear-cut subtypes of dyslexia exist which might have different causes, e.g. specific visual deficits, pertaining to visual short-term memory, or sequential processing. The fourth chapter discusses different possible origins of dyslexics' reading deficits. The authors compare classical phonological impairment explanations with competing sensory-motor impairment explanations. They conclude that results so far are more in line with a phonological explanation and put forward new hypotheses about the specific phonological deficit found in dyslexia, proposing a deficit in categorical perception, i.e. assuming that a dyslexic reader's speech perception is based on allophonic rather than on phonemic representations (pp. 152). The last chapter (Chapter 5) attempts to propose a general framework for explaining developmental dyslexia in alphabetic orthographies, based on the results of studies of both typical and dyslexic readers. The authors first review the main results presented in the preceding chapters, focusing on the automaticity of visual word processing in skilled readers, phonemic vs. allophonic speech perception in dyslexic readers, the role of sublexical and lexical reading, the grain size of processing units, compensatory strategies in dyslexics, and data on the functional neuro-anatomy in typical and dyslexic developing readers. The chapter ends with a sketch of a possible model of developmental dyslexia, which integrates the findings presented so far. It takes into account the different levels at which the dyslexia-specific dysfunctions can occur: the neurobiological level, the cognitive level, and the behavioral level. The model also depicts natural compensation strategies and includes environmental factors like the transparency of a given orthography and print and schooling opportunities. In summary, this is a captivating book about the acquisition of literacy in typical and dyslexic populations. It is well written, and the authors describe the results of the behavioral studies they discuss in sufficient detail to help the reader fully understand the issues and topics presented, making judicious use of tables and figures. The cross-linguistic focus of this book is an asset. The authors might have opted to include Dutch in the set of orthographies that they chose to investigate in greater detail, as there is a large body of literature, both on the development of typically developing readers (e.g. Ziegler et al. 2010) as well as on dyslexic readers. Since Dutch and English share a lot of linguistic characteristics but are very different with respect to their orthographic depth, a comparison of literacy development in these two languages would have allowed for fruitful contrasts. Another topic that might have fit well into this volume is the acquisition of reading by bi- or multilingual developing readers (e.g. Bialystok 2007), an area that might receive increasing interest with increasing globalization.