Trait anger representation in microstructural white matter tracts: A diffusion MRI study

Area of Science:

• Neuroscience
• Psychiatry
• Psychology

Background:

• Understanding brain microstructure is crucial for psychology and psychiatry.
• White matter (WM) tracts underlying emotions, specifically anger, were investigated.
• Potential sex differences in brain-emotion relationships were explored.

Purpose of the Study:

• To investigate white matter (WM) tracts associated with anger using diffusion magnetic resonance imaging (DMRI) connectometry.
• To explore potential sex differences in the relationship between brain structure and anger.
• To identify specific brain circuits involved in anger expression and temperament.

Main Methods:

• Diffusion magnetic resonance imaging (DMRI) connectometry was employed.
• 225 healthy participants from the LEMON database were assessed using the State-Trait Anger Expression Inventory (STAXI).
• Multiple regression models analyzed correlations between local connectomes and STAXI components, controlling for age and handedness.

Main Results:

• No significant sex differences were found in state or trait anger levels.
• In males, quantitative anisotropy (QA) in bilateral corticospinal tract (CST), splenium of corpus callosum (SCC), and other tracts negatively correlated with trait anger and trait anger temperament (TAT).
• In females, QA in bilateral CST and SCC showed a positive correlation with trait anger and TAT, but this did not reach statistical significance.

Conclusions:

• This is the first DMRI connectometry study to investigate WM circuits involved in anger.
• Limbic system and movement-related pathways were linked to trait anger and anger expression in men.
• No significant brain pathways related to anger were identified in women in this study.