139 General discussion 6 Compensatory role of semantic abilities Regarding the first research question, results of the current dissertation showed that within a group of children with dyslexia, semantic abilities are indirectly related to reading efficiency and directly to the number of spelling errors. It was found in chapter 2 that within a group of children with dyslexia, semantic abilities were related to both word decoding efficiency and pseudoword decoding efficiency indirectly via phonological awareness and rapid naming. Strong semantic abilities seem to provide children with dyslexia with a boost to strengthen their phonological skills and rapid naming skills, which in turn facilitate their reading abilities. Furthermore, in Chapter 4, better verbal working memory was found to be related to fewer morphological errors and on top of that higher scores on semantic abilities were related to fewer phonological, morphological and orthographic spelling errors among children with dyslexia. Children with better verbal working memory made fewer morphological errors and children with stronger semantic abilities are thus relatively better in spelling accuracy than children with less well-developed semantic abilities. In addition to the possible impact of semantic abilities, the relation between verbal learning and reading and spelling outcomes was studied in chapter 5. Verbal learning can be seen as a dynamic assessment of semantic abilities. Results showed that verbal learning was not related to reading but it was related to spelling skills. Children that were able to learn more verbally presented words due to repetition performed better on spelling. Verbal consolidation was not related to reading, nor spelling. The ability to maintain verbally presented words in memory showed no impact on reading and spelling. The aforementioned results indicate that lexical specificity (in this case semantic specificity) may help children with dyslexia to improve their phonological awareness (see Metsala, 1999) and to become better at lexical retrieval (see Wolf et al., 2016), which, in turn, may have a positive impact on decoding efficiency. As described in the lexical restructuring hypothesis, well-developed semantic representations also stimulate growth of phonological representations (Metsala & Walley, 1998). This is in line with the suggestions that semantic abilities help to circumvent phonological decoding deficits as mentioned by Haft et al. (2016) and is in line with findings by Van Viersen et al (2018) who found that (early) semantic abilities are at the base of preliteracy and word decoding skills. Prior research also found the reverse effect in which deficits in the semantic development are associated with later reading development as well (Van Viersen et al. (2017). The absence of a direct relation between semantic abilities and word decoding efficiency is neither in line with previous research (Van Bergen et al., 2014a) nor with the lexical quality hypothesis (Perfetti & Hart, 2002). Finding indirect and not direct relations of semantic abilities on reading efficiency could be due to the fact that the children with dyslexia in the current thesis are in the early stages of their
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