LEFT VERSUS RIGHT HEMISPHERE DIFFERENCES IN BRAIN CONNECTIVITY: 4-TESLA HARDI TRACTOGRAPHY IN 569 TWINS.

Area of Science:

• Neuroscience
• Brain Imaging
• Human Anatomy

Background:

• Diffusion imaging is a key technique for mapping brain connectivity.
• Brain asymmetries are known to influence speech and language, but hemisphere-specific wiring differences are less understood.

Purpose of the Study:

• To investigate left/right hemisphere differences in brain wiring using high-angular resolution diffusion imaging.
• To explore how age influences brain connectivity asymmetry and network topology.

Main Methods:

• Scanned 457 young adults and 112 adolescents using 4-Tesla high-angular resolution diffusion imaging.
• Extracted brain fiber tracts and created 70x70 connectivity matrices based on fiber proportions.
• Analyzed asymmetry in connectivity matrices and network topology measures.

Main Results:

• Identified significant differences in fiber proportions connecting left and right hemisphere cortical regions.
• Observed that the degree of connectivity asymmetry varied with age.
• Found age-related changes in network topology measures, including the small-world effect.

Conclusions:

• Demonstrated distinct anatomical connectivity patterns between the left and right brain hemispheres.
• Established that brain wiring asymmetry is age-dependent.
• Highlighted the role of age in shaping brain network topology and hemispheric specialization.