Are there differences in brain morphology according to handedness?

Area of Science:

• Neuroscience
• Human Anatomy
• Brain Imaging

Background:

• Handedness, the preference for using one hand over the other, is a common human trait.
• While often associated with cognitive functions, the influence of handedness on brain structure, particularly subcortical regions, remains an area of active investigation.

Purpose of the Study:

• To investigate and compare brain morphology differences between right-handed and non-right-handed individuals.
• To explore correlations between handedness measures and specific brain structure volumes.

Main Methods:

• Utilized 3D T1-weighted MRI and diffusion tensor imaging on 42 healthy participants (21 right-handers, 21 non-right-handers).
• Assessed cortical morphology (thickness, surface area, volume, curvature) and subcortical structure volumes (amygdala, caudate, hippocampus, globus pallidus, putamen, thalamus).
• Classified handedness using the Edinburgh Handedness Inventory.

Main Results:

• Non-right-handed individuals exhibited significantly larger volumes in the right putamen and left globus pallidus compared to right-handers.
• These basal ganglia volumes showed a negative correlation with handedness scores.
• No significant differences were found in cortical morphology or other subcortical structures, nor in white matter integrity.

Conclusions:

• Significant brain morphology differences exist between right-handers and non-right-handers, predominantly within the basal ganglia.
• These structural variations in the basal ganglia may underlie differences in motor control associated with handedness.