Double Dissociation Between Reading and Spelling Deficits

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

“…This seems to be in line with the findings of studies with unselected samples of German-speaking children showing that phonological awareness and phonological short-term memory are significant predictors of spelling, but not of reading fluency (e.g., Landerl & Wimmer, 2008;Mann & Wimmer, 2002;Mayringer, Wimmer, & Landerl, 1998;Moll et al, 2014). However, working with a group of third-and fourth-grade German-speaking children, Moll and Landerl (2009) failed to find differences between good readers/poor spellers and good readers/good spellers in phonological awareness. Similarly, Chatzoudi and Papadopoulos (2013) found no significant differences between groups on phonological short-term memory in Greek.…”

“…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). …”

“…More specifically, because RAN is a speeded measure, selecting poor readers in consistent orthographies with reading fluency measures, may have inflated the role of RAN. In contrast, selecting poor spellers with spelling accuracy measures (as in Wimmer & Mayringer, 2002or Moll & Landerl, 2009, may have deflated the role of RAN. Examining the role of RAN in the context of unexpected reading and spelling deficits is interesting in light of Bowers and Wolf's (1993) proposal, according to which RAN is related to reading because of its contribution to the development of orthographic knowledge.…”

“…However, because of overreliance on phonological recoding, children do not move quickly from a sequential processing of letters to a parallel processing of letters. In turn, Moll and Landerl (2009) suggested that this performance pattern may be due to unexpectedly slow access to orthographic representations. As spelling is generally slower than reading, a deficit in the speed with which orthographic representations are accessed would impact word recognition speed, but not spelling accuracy.…”

“…However, the imperfect correlation between the two (rs range from .60 to .80; see meta-analysis by Swanson, Trainin, Necoechea, & Hammill, 2003) leaves open the window for a dissociation in which good readers can also be poor spellers (known as unexpected poor spellers) and poor readers can also be good spellers (known as unexpected poor readers). A few large-scale studies have indeed shown that these two performance profiles are not rare and may each affect 3-7% of school-age children (Fayol, Zorman, & Lété, 2009;Moll, Kunze, Neuhoff, Bruder, & Schulte-Körne, 2014;Moll & Landerl, 2009;Wimmer & Mayringer, 2002).…”