Poster B23, Tuesday, August 20, 2019, 3:15 – 5:00 pm, Restaurant Hall
Differences in the latent structure of language abilities in 8-year-old children with or without a familial risk of dyslexia
Soila Kuuluvainen1, Julia Varjola1, Piia Turunen1, Teija Kujala1;1Cognitive Brain Research Unit, Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki
Developmental dyslexia is a difficulty in learning to read in children with otherwise typical cognitive development, who have received normal reading instruction. It is estimated to be highly hereditary, with 35-50 % of children of dyslexic parents also developing dyslexia. These children, due to their family background, are often referred to as children at risk for dyslexia. One of the main theories attributes dyslexia to deficits in phonological processing, either in encoding or in manipulation, or both. However, dyslexics also often have problems in rapid alternating naming tasks, verbal working memory, and some also have poorer verbal reasoning compared to their nonverbal reasoning abilities. However, these tasks share a considerable proportion of variance. First, sufficient language-specific phonological representations lay the foundation to all language skills. Secondly, the ability to efficiently retrieve, maintain and manipulate verbal material in working memory is essential to any task requiring more than simple repetition of short utterances. Thus, Ramus et al. (2013), in their exploratory factor analysis, succeeded in separating verbal skills in 8-12-year-old English-speaking children with specific language impairment (SLI), dyslexia and their typically developed peers into three factors: phonological representations, phonological skills, and non-phonological skills. The latter two have higher cognitive requirements than the first, which only requires short-term maintenance and identification of phonological material. The current study aimed to confirm the results of Ramus et al. (2013) in a sample of 152 Finnish 8-year-old children, and further explore the differences in latent structure of language abilities in children at risk for dyslexia (N=84) and their controls (N=68). Language tests used consisted of NEPSY II Phonological processing, Word Lists, and Comprehension of Instructions, NEPSY-I Repetition of Nonwords, Rapid Alternating Naming of colours and objects, WISC-III Numbers forward and backward, and the Boston Naming Test. The confirmatory factor analysis revealed that the current data did not fit to the factor structure proposed by Ramus et al. (2013). However, the exploratory factor analyses showed good fit of a three-factor structure in both children at risk for dyslexia and their controls. The factor structures differed in these two groups, suggesting differences in the latent structure of language abilities in these two groups. The typically developed children’s factor structure suggested their phonological abilities to be at a level where they do not appear as an independent factor, but rather are combined with more difficult linguistic tasks, namely the Comprehension of Instructions. The at-risk children, however, showed a phonological representations/abilities factor, with high loadings from Phonological Processing and Repetition of Nonwords tasks. In addition, both groups showed a second factor reflecting verbal short-term memory and a third reflecting rapid naming ability. The differences to the results of Ramus et al. (2013) are likely to arise from the different age and language of the tested children, the current study lacking the SLI group, as well as differences in the tests employed.
Themes: Disorders: Developmental, Phonology and Phonological Working Memory
Method: Behavioral