Robin van Rijthoven

16 Chapter 1 To sum up, the Multifactorial causal model of dyslexia implies that reading and spelling difficulties are a consequence of a complex interplay of strengths and weaknesses (Astle & Fletcher-Martin, 2020) and in such a model semantic abilities could be a strength to rely on. However, despite the clear role of semantic abilities in brain studies that found overcompensation among children with dyslexia in verbal areas (e.g., Shaywitz et al., 2005) and the triangular framework (see Seidenberg & McClelland, 1989), most research regarding children with dyslexia focused on the weak bi-directional relationship between phonological and orthographic representations, instead of focusing on the possible compensatory role of broad and deep semantic abilities. Research on the role of semantic abilities is limited and mostly includes measures of broad semantic knowledge rather than the deeper knowledge that is important in order to compensate for weak phonological representations (Li et al., 2004). Moreover, the available researchmostly does not include children with the actual diagnosis of dyslexia, while specific explanations, such as a general learning disability, inadequate teaching, or sensory impairments are ruled out in the assessment and therefore a group of children with a specific reading and/ or spelling problem remains. Furthermore, besides the role of verbal abilities present in children, the possibility to learn and maintain new verbal information could be important as well. These processes take place in the overactivated areas of the brain of children with dyslexia. Research regarding learning and maintaining verbal information (verbal learning and consolidation), however, is limited and still inconclusive. Compensatory phonics through spelling intervention As reading and spelling are both very important skills (seeDeGreef et al., 2014; Savolainen et al., 2008;), children with dyslexia need help to overcome their difficulties and become better at reading and spelling by building strong and bi-directional phonologyorthography connections. Previous research showed that phonics interventions were relatively successful at helping children with reading disabilities in strengthening the connections between phonological and orthographic representations and thereby improved both reading and spelling results (see review by Galuschka et al., 2014 and meta-analysis by Ehri et al., 2001). Galuschka and colleagues (2014) showed that a phonics intervention was, compared to reading fluency training, phoneme awareness instructions, reading comprehension trainings, auditory trainings, medical treatment, and coloured overlays or lenses, the only intervention with statistical confirmed efficacy on reading and spelling. A phonics intervention (i.e., a combination of reading fluency training and phonemic awareness training) includes systematic instruction of lettersound-correspondences, decoding strategies, and the application of these skills in reading and writing activities (Galuschka et al., 2014). However, considerable individual variation in response to intervention exists (Galuschka et al., 2014) and research including both strengths and weakness profiles is limited (see Burns et al., 2016). In a subgroup