Does white matter structure relate to hemispheric language lateralization? A systematic review

Area of Science:

• Neuroimaging
• Neuroscience
• White Matter Research

Background:

• Functional language lateralization is complex.
• Diffusion MRI offers insights into white matter's role.
• Understanding white matter correlates of language dominance is crucial.

Purpose of the Study:

• To systematically review diffusion MRI studies on white matter and functional language dominance.
• To synthesize findings on white matter tracts associated with language lateralization.
• To identify challenges and suggest future research directions.

Main Methods:

• Systematic literature search of Web of Science, Scopus, and Ovid MEDLINE.
• Inclusion of 25 studies involving adults (epilepsy, tumors, healthy controls).
• Analysis of diffusion MRI metrics and their association with language lateralization.

Main Results:

• Arcuate fasciculus and corpus callosum commonly linked to language lateralization in clinical groups.
• Findings in healthy individuals are variable, influenced by handedness.
• Temporal lobe regions show stronger diffusion MRI correlations than frontal areas.

Conclusions:

• White matter's role in language lateralization is complex and population-dependent.
• Methodological inconsistencies hinder cross-study comparisons.
• Future research needs larger samples, whole-brain approaches, and standardized methods.