Brain morphometry in reading-disabled twins

Area of Science:

• Neuroimaging
• Developmental Neuroscience
• Cognitive Neuroscience

Background:

• Brain structural correlates of reading disability (RD) remain debated.
• Previous studies have yielded inconsistent findings.
• This study investigates a wider range of brain structures in the largest sample to date, controlling for key covariates.

Purpose of the Study:

• To identify differences in brain structure in individuals with reading disability (RD) using MRI-based morphometry.
• To compare brain volumes and cortical development patterns between individuals with and without RD.
• To determine if observed differences are influenced by comorbid attention deficit hyperactivity disorder (ADHD).

Main Methods:

• A case-control study involving 75 individuals with RD and 22 controls.
• Participants were assessed using MRI-based morphometry to measure brain structure volumes.
• Analyses included group-by-structure comparisons of neocortical, subcortical, and corpus callosum regions, controlling for age, gender, IQ, and ADHD status.

Main Results:

• A significant group-by-structure interaction was found for neocortical subdivisions, indicating altered developmental patterns in RD.
• The insula and anterior superior neocortex were smaller in the RD group, while the retrocallosal cortex was larger.
• No significant differences were observed in subcortical or callosal structures between groups, even in subjects without ADHD.

Conclusions:

• Cortical development is subtly altered in individuals with reading disability, with specific regional differences observed.
• Findings replicate and extend previous research on insular differences in RD.
• These brain structure differences in RD are not attributable to comorbid ADHD.