Sex differences in parietal lobe morphology: relationship to mental rotation performance

Area of Science:

• Neuroscience
• Neuroimaging
• Human Brain Anatomy

Background:

• Structural magnetic resonance imaging (MRI) studies reveal sexual dimorphism in the human brain.
• Differences in gray matter (GM) and white matter (WM) proportions are noted, especially in the parietal lobe.
• No prior studies have linked parietal lobe structural sex differences to functional outcomes like spatial ability.

Purpose of the Study:

• To investigate sex differences in parietal lobe structure.
• To correlate observed structural differences with performance on the mental rotations test (MRT).
• To explore the neurobiological basis of sex differences in spatial cognition.

Main Methods:

• Utilized structural magnetic resonance imaging (MRI) to assess brain morphology.
• Quantified gray matter (GM) and white matter (WM) volumes and surface area in the parietal lobe.
• Administered the mental rotations test (MRT) to evaluate spatial ability.

Main Results:

• Women exhibited proportionately greater parietal lobe gray matter volume compared to men.
• This increased GM volume in women was associated with lower performance on the MRT.
• Men showed proportionately greater parietal lobe surface area, linked to enhanced MRT performance.

Conclusions:

• Parietal lobe structure exhibits sexual dimorphism.
• Differences in gray matter proportion and surface area correlate with sex-based variations in mental rotation ability.
• These findings suggest a neurobiological basis for sex differences in spatial cognition related to parietal lobe morphology.