Microstructural abnormalities in the ATR and VOF underlie tone awareness deficits in Chinese children with developmental dyslexia: a DTI study

ObjectiveTone awareness is crucial for reading in Chinese children, significantly affecting those with developmental dyslexia (DD). This paper identifies microstructural abnormalities in the inferior fronto-occipital fasciculus (IFOF), uncinate fasciculus (UF), anterior thalamic radiation (ATR), and vertical occipital fasciculus (VOF) in Chinese children with DD and evaluates their potential relationships with tone awareness and DD.Methods35 children with DD and 64 typically developing (TD) children were recruited from Guangdong Province, China. Diffusion tensor imaging (DTI) measured mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD), and fractional anisotropy (FA). The Tone Awareness Judgment Task was used to measure tone awareness. Generalized linear regression and mediation models were used to explore associations and mediating effects.ResultsChildren with DD showed significantly lower MD, AD, and RD values in the bilateral IFOF and ATR, and right VOF compared to TD children, with no significant FA abnormalities. Limited associations between white matter microstructure and tone awareness were observed in the bilateral ATR and right VOF, but these associations did not survive multiple-comparison correction. Tone awareness mediated the relationships between microstructural abnormalities in the bilateral ATR and right VOF and DD.ConclusionsMicrostructural abnormalities in the bilateral ATR and right VOF may be related to DD partly through tone awareness, although direct associations between tract microstructure and tone awareness were limited.