Cortical thickness lateralization and its relation to language abilities in children

Area of Science:

• Neuroscience
• Developmental Psychology
• Linguistics

Background:

• Brain asymmetry is present from early life and evolves with age.
• Language is a highly lateralized cognitive function with a known developmental trajectory.
• The relationship between age-related structural brain asymmetry and language performance changes is not fully understood.

Purpose of the Study:

• To investigate the development of structural brain asymmetry in children.
• To examine the link between these structural changes and improvements in language comprehension.
• To understand the role of the inferior frontal gyrus (IFG) in language acquisition.

Main Methods:

• Longitudinal structural magnetic resonance imaging (MRI) data collection from children aged 5 to 6 years.
• Analysis of changes in cortical thickness asymmetry over time.
• Correlation of brain asymmetry development with language comprehension performance.

Main Results:

• Significant improvements in language performance were observed over the study period.
• These language gains were associated with changes in cortical thickness asymmetry in the triangular part of the inferior frontal gyrus (IFG).
• Greater cortical thinning in the left triangular IFG compared to the right was linked to language improvement.
• Brain asymmetry at ages 5-6 predicted language performance at age 7.

Conclusions:

• Children's language improvement, particularly sentence comprehension, appears to depend on structural asymmetry changes in the IFG.
• This study provides the first longitudinal evidence for the IFG's crucial role in language acquisition during early childhood.
• The findings underscore the importance of structural brain development in the IFG for language skill enhancement.