Diffusion tensor quantification of the relations between microstructural and macrostructural indices of white matter...

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Cognitive Neuroscience

Background:

• The relationship between white matter microstructure and reading skills remains debated.
• Previous studies primarily focused on fractional anisotropy, limiting comprehensive understanding.
• This study incorporates macroscopic volume and multiple microstructural indices for enhanced interpretability.

Purpose of the Study:

• To investigate the relationship between fronto-temporo-parietal white matter microstructure and reading skills.
• To compare white matter structure in adolescents and adults with and without reading difficulties.
• To differentiate the roles of association and projection white matter pathways in reading.

Main Methods:

• Diffusion tensor imaging (DTI) was used to analyze major white matter pathways.
• An atlas-based algorithm was applied to DTI data.
• Linear models analyzed the relationship between white matter indices, reading group, hemisphere, and reading skills.

Main Results:

• White matter microstructural indices correlated with sublexical decoding performance.
• The relationship between microstructural indices, reading ability, and reading group varied between association and projection pathways.
• Changes in projection pathways suggested alterations in white matter organization and axonal size.
• Changes in association pathways indicated alterations in pathway complexity.
• Macrostructural changes corresponded with microstructural findings.

Conclusions:

• The relationship between white matter microstructure and reading ability differs between association and projection pathways.
• Both macrostructure and microstructure are relevant to understanding reading-related brain differences.
• Findings provide a more nuanced view of white matter's role in reading skills.