Deficient Explicit Access to Phonological Representations Explains Phonological Fluency Difficulties in Greek Children With Dyslexia and/or Developmental Language Disorder

Abstract

It is well-established that children with dyslexia and/or Developmental Language Disorder (hereafter children with DDLD) perform poorly on phonological tasks compared to typically developing (TD) children. However, there has been some debate as to whether their phonological deficit arises directly from an impairment in phonological representations, or instead from deficient access to (intact) phonological representations. This study tested the Degraded Phonological Representations Hypothesis and the Deficient Phonological Access Hypothesis using a task that is not often used with children with DDLD, namely phonological fluency. Both hypotheses predict that children with DDLD will retrieve fewer items than their TD peers in the phonological fluency task. However, while the Degraded Phonological Representations Hypothesis predicts smaller clusters of phonologically related items in children with DDLD, the Deficient Phonological Access Hypothesis predicts that the two groups will not differ in cluster size. How phonological fluency performance related to children’s language, literacy, and phonological skills was investigated. Further, the specificity of a phonological fluency deficit in children with DDLD was tested using a nonverbal (design) fluency task. Sixty-six children with DDLD aged 7–12 years and 83 TD children aged 6–12 years, all monolingual Greek speakers, were tested on three phonological fluency categories, on nonverbal IQ, language, literacy, and phonological tasks, and on a design fluency task. The DDLD group produced significantly fewer correct responses and fewer switches compared to the TD group, but the two groups showed similar clustering and average cluster size. After controlling for age, children’s language, literacy, and phonological skills significantly predicted the number of correct responses produced. The two groups did not differ significantly on the number of unique designs generated in the design fluency task. Furthermore, children with DDLD showed poorer phonological fluency performance relative to their TD peers even after design fluency performance was controlled, demonstrating the specificity of their phonological fluency deficit. This study adds to the theoretical debate on the locus of the phonological deficit in dyslexia and DLD. The findings support the hypothesis that the phonological deficit in dyslexia and DLD lies in deficient explicit access to intact phonological representations.

Language-Related Skills in Bilingual Children With Specific Learning Disorders

“…Conversely, studies of the impact of bilingualism on this task are not univocal; although some have found evidence for a bilingual advantage, others have found evidence for a frailty in bilinguals in this respect (Chen et al, 2004 ; Hipfner-Boucher et al, 2014 ; Bonifacci et al, 2018 ). In the four groups in the present study, no other significant differences emerged in phonological and semantic fluency, which confirms the findings of some previous studies on SLD but contradicts others that noted a specific deficit in children with SLD (Bental and Tirosh, 2007 ; Mengisidou and Marshall, 2019 ). The present results are otherwise congruent with recent research on bilingualism (Giovannoli et al, 2020 ).…”

Semantic fluency difficulties in developmental dyslexia and developmental language disorder (DLD): poor semantic structure of the lexicon or slower retrieval processes?

“…Traditionally, dyslexia and DLD are viewed as separate disorders. In the current study, however, the children with dyslexia and DLD were combined in one group, the DDLD group, as proposed for this same group of participants by Mengisidou and Marshall (). In fact, literacy difficulties are very common in children with DLD, and it is the case that approximately 50% of children who fit the criteria for dyslexia also fit the criteria for DLD, and vice versa (e.g., Messaoud‐Galusi and Marshall , Spanoudis et al .…”

Exploring the phonological profiles of children with reading difficulties: A multiple case study

“…They proposed the Phonological Access Hypothesis to account for these findings, suggesting that the phonological deficit in Dyslexia may arise due to difficulties accessing phonological representations, rather than the quality of the representations themselves. This theory has continued to gain support from studies of children (Mengisidou & Marshall, 2019) and adults (Boets et al, 2013). Bearing in mind some of the issues with averaging across groups of participants when studying heterogeneous developmental disorders (Carroll et al, 2016), the current study aims to complement these group-level findings by exploring the different patterns of strengths and weaknesses that may occur within the phonological profiles of individual children.…”