Structural brain dynamics across reading development: A longitudinal MRI study from kindergarten to grade 5.

Area of Science:

• Neuroscience
• Developmental Psychology
• Educational Psychology

Background:

• Primary education is crucial for developing literacy and independence.
• Brain development during early academic learning, particularly reading, involves complex regional changes.
• The relationship between these brain changes and reading ability is not fully understood.

Purpose of the Study:

• To investigate typical cortical development during early and advanced reading stages using longitudinal MRI data.
• To identify deviations in brain development trajectories in children with dyslexia compared to typical readers.
• To determine the critical period for reading plasticity in the developing brain.

Main Methods:

• Longitudinal T1 MRI data from 41 children were analyzed.
• A novel measure quantified local structural brain changes between time points, accounting for global head growth.
• Children were assessed during early (kindergarten-grade 2) and advanced (grade 2-grade 5) reading stages.

Main Results:

• Typical cortical development revealed increases in left temporal and temporoparietal reading network regions during the early stage, stabilizing later.
• No significant differences in gray matter development of the left reading network were found between children with and without dyslexia.
• Deviant neurotrajectories were observed in the right inferior frontal gyrus (IFG) opercularis during the early stage and right isthmus cingulate during the advanced stage in children with dyslexia.

Conclusions:

• The critical plasticity window for reading acquisition appears to be in the early years of primary school.
• Early intervention for reading difficulties may be more effective if aligned with this developmental window.
• Observed differences in right-hemisphere regions in dyslexia may indicate compensatory neural mechanisms.