Role of White Matter Microstructure in Impulsive Behavior.

Area of Science:

• Neuroscience
• Neuroimaging
• Behavioral Science

Background:

• Impulsivity is a key trait in neuropsychiatric disorders like addiction.
• Individual differences in impulsivity exist even in healthy populations.
• Altered white matter microstructure is implicated in various neurological conditions.

Purpose of the Study:

• To investigate the relationship between white matter microstructure and normal individual variability in impulsive behaviors.
• To test if cerebral white matter integrity underlies differences in impulsivity among healthy adults.

Main Methods:

• Collected diffusion tensor imaging (DTI) data and impulsivity scores from 74 healthy adults.
• Assessed impulsivity using the Barratt Impulsiveness Scale-11 (total and subdomains: attentional, motor, nonplanning).
• Analyzed whole-brain and regional white matter fractional anisotropy (FA) in 24 tracts using the Enhancing Neuro Imaging Genetics Through Meta Analysis-DTI pipeline.

Main Results:

• Whole-brain FA was inversely correlated with motor impulsivity (r=-0.32, p=0.007).
• Whole-brain FA was positively correlated with nonplanning impulsivity (r=0.29, p=0.02).
• Specific regional FA values in the corticospinal and superior fronto-occipital fasciculus tracts also correlated significantly with motor and nonplanning impulsivity, respectively.

Conclusions:

• Motor and nonplanning impulsivity subdomains are associated with distinct white matter microstructural connectivity.
• These findings support impulsivity as a network-based construct.
• White matter microstructural integrity plays a role in impulsivity within healthy individuals.