Helland, T. 1 & Hugdahl, K. 1, 2
1 University of Bergen, Bergen, Norway
2 Haukeland University Hospital, Bergen, Norway
During the period children learn to read and write a gradual shift from right to left hemisphere dominance for language is typically seen. However, in children with dyslexia a deviant pattern is described in the literature. The present study aimed at assessing this development and its correspondence to stages of literacy acquisition.
Children at risk of developing dyslexia and matched controls were followed with a broad assessment battery from the ages of five till eleven. Dichotic listening (DL) was used to assess the development of brain laterality, and RAN, reading and spelling test were used to assess linguistic and literacy skills.
Contrary to the dyslexia group the typical group showed an increasing shift from right to left hemisphere dominance during the pre-literacy, emergent literacy and literacy stages. Although the correlations with the language scores in general were weak, it was stronger in the dyslexia group than in the typical group.
The main finding was that the developmental pattern of brain laterality from the age of five to eleven in children with dyslexia differed from the typical group. The interaction between the laterality and language scores in dyslexia needs further investigation, as i.e. assessing effects of DL training on literacy skills.