Predictors of developmental dyslexia in European orthographies with varying complexity

Abstract

14Centre référent pour le diagnostic des troubles du langage et des apprentissages, Département de pédiatrie, CHU Nord, Grenoble, France; Background: The relationship between phoneme awareness, rapid automatized naming (RAN), verbal short-term/working memory (ST/WM) and diagnostic category is investigated in control and dyslexic children, and the extent to which this depends on orthographic complexity. Methods: General cognitive, phonological and literacy skills were tested in 1,138 control and 1,114 dyslexic children speaking six different languages spanning a large range of orthographic complexity (Finnish, Hungarian, German, Dutch, French, English). Results: Phoneme deletion and RAN were strong concurrent predictors of developmental dyslexia, while verbal ST/WM and general verbal abilities played a comparatively minor role. In logistic regression models, more participants were classified correctly when orthography was more complex. The impact of phoneme deletion and RAN-digits was stronger in complex than in less complex orthographies. Conclusions: Findings are largely consistent with the literature on predictors of dyslexia and literacy skills, while uniquely demonstrating how orthographic complexity exacerbates some symptoms of dyslexia.

The precursors of double dissociation between reading and spelling in a transparent orthography

“…As expected, the group with both reading and spelling difficulties (RSD) had the greatest difficulties, and they performed more poorly on all kindergarten cognitive skills than good readers/good spellers and more poorly than the RD group on most of the tasks. This performance profile aligns well with that of children with dyslexia, who have been shown in several previous studies to have deficits in RAN (e.g., de Jong & van der Leij, 2013;Georgiou, Papadopoulos, Zarouna, & Parrila, 2012;Wimmer, 1993), letter knowledge (e.g., Eklund, Torppa, & Lyytinen, 2013;Lervåg, et al, 2009;Torppa et al, 2006), and phonological awareness (e.g., Landerl et al, 2013;Nikolopoulos, Goulandris, & Snowling, 2003). Previous studies on double dissociation between reading and spelling have also shown that the group with both reading and spelling difficulties has the most severe cognitive difficulties (e.g., Chatzoudi & Papadopoulos, 2013;Fayol et al, 2009;Moll & Landerl, 2009).…”

“…This makes reading Finnish very straightforward, and reading errors are rare, even for poor readers after the beginning stages of reading acquisition (e.g., Aro, 2004, in press). However, slow reading and erroneous spelling are not uncommon in Finnish (see Eklund et al, 2015;Kairaluoma et al, 2013;Landerl et al, 2013). These findings show that reading and spelling difficulties do not necessarily co-occur and support the development of clear diagnostic criteria and early intervention programs that would target each condition.…”

“…If the cognitive basis of reading and spelling deficits differs, the kindergarten cognitive profiles of the deficit groups might differ as well. Because reading in our study was operationalized with reading fluency measures (due to lack of variability in reading accuracy measures in Finnish) and spelling with an accuracy measure, we expected that slow reading would be associated with slow RAN (e.g., de Jong & van der Leij, 2002;Eklund et al, 2013;Georgiou et al, 2011;Landerl et al, 2013;Wimmer et al, 1998) and inaccurate spelling would be associated with phonological problems (e.g., Furnes & Samuelsson, 2011;Landerl & Wimmer, 2008;Mayringer et al, 1998;Moll et al, 2014;Niolaki, Masterson, & Terzopoulos, 2013). Second, letter knowledge in kindergarten has been found to be a key predictor of reading and spelling skills (e.g., Kirby, Parrila, & Pfeiffer, 2003;Leppänen, Niemi, Aunola, & Nurmi, 2004;Lerkkanen, Rasku-Puttonen, Aunola, & Nurmi, 2004;Schatschneider, Fletcher, Francis, Carlson, & Foorman, 2004), and in the present study the role of letter knowledge is for the first time examined with respect to unexpected reading and spelling deficits.…”

“…Rapid automatized naming (RAN), an index of the speed of lexical access, has long been identified as a marker of reading speed deficits in several consistent orthographies (e.g., Brizzolara et al, 2006;de Jong & van der Leij, 2002;Eklund et al, 2013;Georgiou, Parrila, Manolitsis, & Kirby, 2011;Landerl et al, 2013;Wimmer, Mayringer, & Landerl, 1998). In the only study that examined the role of RAN in the context of unexpected reading and spelling deficits, Wimmer and Mayringer (2002) confirmed that poor readers/good spellers suffered from a selective RAN deficit.…”

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

“…The increasing research on dyslexia in different orthographies points to a reevaluation of core deficits in dyslexia (see e.g. Blomert & Willems, 2010; Landerl et al ., 2013; Torppa, Lyytinen, Erskine, Eklund, & Lyytinen, 2010). Studies of L1 and L2 learning indicate that orthographic transparency or script plays an important role for how PA in literacy acquisition should be evaluated (see e.g.…”