Atypical gray matter in children with dyslexia before the onset of reading instruction

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Cognitive Neuroscience

Background:

• Previous research on dyslexia neuroanatomy primarily focused on school-aged children and adults.
• Limited understanding exists regarding early neuroanatomical markers in pre-readers at risk for dyslexia.

Purpose of the Study:

• To investigate gray matter surface area and cortical thickness in pre-readers with and without a family risk for dyslexia.
• To identify neuroanatomical differences associated with the development of dyslexia before formal reading instruction.

Main Methods:

• Surface-based analyses using FreeSurfer were conducted on 54 pre-readers (31 with family risk, 23 without).
• Neuroimaging focused on core reading network regions in both left and right hemispheres.
• Comparison between children who developed dyslexia and those who did not, as well as between risk groups.

Main Results:

• Pre-readers who later developed dyslexia exhibited reduced surface area in bilateral fusiform gyri.
• Family risk for dyslexia, regardless of later reading ability, was associated with surface area anomalies in bilateral inferior and middle temporal gyri.
• Observed differences were primarily in surface area, not cortical thickness.

Conclusions:

• Neuroanatomical anomalies associated with dyslexia are present at the pre-reading stage.
• These early differences suggest dyslexia is not solely a consequence of reading experience.
• Findings highlight the potential for early identification of dyslexia-related neurodevelopmental variations.