Authors: Stijn Van Der Auwera, Maaike Vandermosten, Jan Wouters, Pol Ghesquière, Jolijn Vanderauwera.
Publication: (Elsevier). 118087 2021 | DOI: 10.1016/j.neuroimage.2021.118087
Although the neural basis of dyslexia has intensively been investigated, results are still unclear about the existence of a white matter deficit in the arcuate fasciculus (AF) throughout development. To unravel this ambiguity, we examined the difference in fractional anisotropy (FA) of the AF between children developing dyslexia and children developing typical reading skills in a longitudinal sample with three MRI time points throughout reading development: the pre-reading stage (5-6 years old), the early reading stage (7-8 years old) and the advanced reading stage (9-10 years old). Applying along-the-tract analyses of white matter organization, our results confirmed that a white matter deficit existed in the left AF prior to the onset of formal reading instruction in children who developed dyslexia later on. This deficit was consistently present throughout the course of reading development. Additionally, we evaluated the use of applying a continuous approach on the participants’ reading skills rather than the arbitrary categorization in individuals with or without dyslexia. Our results confirmed the predictive relation between FA and word reading measurements later in development. This study supports the use of longitudinal approaches to investigate the neural basis of the developmental process of learning to read and the application of triangulation, i.e. using multiple research approaches to help gain more insight and aiding the interpretation of obtained results.
Stijn Van Der Auwera, Maaike Vandermosten, Jan Wouters, Pol Ghesquière, Jolijn Vanderauwera, A three-time point longitudinal investigation of the arcuate fasciculus throughout reading acquisition in children developing dyslexia, NeuroImage, 2021,
Our findings indicate that the use of an automated along-the-tract analyses fine-grained approach confirms there is a difference in FA between individuals with and without dyslexia. The structural organization of the left arcuate fasciculus thus seems to be related to (later) reading performance, already prior to the start of formal reading instruction.
Hence, the present results seem to favor the hypothesis that structural organization of the left AF is related to the development of cognitive skills that are predictive of later reading development, such as phonological skills.
The present study confirms the added value of adopting a longitudinal approach to investigate the neural basis of the developmental process of learning to read, compared to the limited results obtained when restricting studies to a cross-sectional design.