Side and handedness effects on the cingulum from diffusion tensor imaging.

Area of Science:

• Neuroscience
• Neuroimaging
• Human Brain Anatomy

Background:

• The cingulum bundle is a crucial white matter tract connecting various brain regions.
• Understanding its microstructure is key to comprehending brain lateralization and handedness.
• Previous studies often used region-of-interest methods, limiting detailed tract analysis.

Purpose of the Study:

• To investigate the microstructural differences in bilateral cingulum bundles related to handedness.
• To compare anisotropy patterns between right-handers and left-handers using a fiber-based approach.
• To explore potential asymmetries in cingulum bundle microstructure.

Main Methods:

• Diffusion tensor imaging (DTI) was used to acquire brain data.
• Fractional anisotropy (FA) was extracted as a measure of white matter integrity.
• A fiber-based scale-invariant parameterization method was employed for detailed tract analysis.
• 31 right-handed and 14 left-handed individuals were included.

Main Results:

• A significant left-greater-than-right asymmetry in FA was observed in most cingulum bundle segments for both handedness groups.
• Higher FA was found in the bilateral cingulum bundles of right-handers compared to left-handers.
• No significant interaction between handedness and side (left vs. right) was detected.

Conclusions:

• The cingulum bundle exhibits consistent left-biased microstructural asymmetry regardless of handedness.
• Right-handers demonstrate generally higher white matter integrity in the cingulum bundle compared to left-handers.
• These findings contribute to understanding the neuroanatomical basis of handedness and brain lateralization.