Networks underlying trait impulsivity: Evidence from voxel-based lesion-symptom mapping

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Impulsivity is a complex trait involving poor self-control and delayed gratification.
• Understanding the neural basis of impulsivity is crucial for treating related behavioral disorders.

Purpose of the Study:

• To investigate the neuroanatomical correlates of global impulsivity and its components.
• To determine if specific brain networks underlie different facets of impulsivity using voxel-based lesion-symptom mapping.

Main Methods:

• Voxel-based lesion-symptom mapping (VLSM) analysis was conducted on 131 patients with penetrating traumatic brain injuries (pTBI).
• Impulsivity was assessed using the Barratt Impulsiveness Scale (BIS-11), measuring global impulsivity and its subcomponents like motor impulsivity.
• Lesion data were correlated with BIS-11 scores to identify brain regions associated with impulsivity.

Main Results:

• Damage to bilateral prefrontal cortex (PFC), left temporal gyri, and left hippocampus correlated with heightened global impulsivity.
• A distinct cluster within the left PFC was specifically associated with motor impulsivity (acting without thinking).
• Findings suggest a complex, partly left-lateralized neuroanatomical network for impulsivity.

Conclusions:

• Behavioral impulsivity involves widespread bilateral prefrontal networks.
• Specific components of impulsivity, like motor impulsivity, may rely on more localized, left-lateralized prefrontal networks.
• The study highlights novel associations between left temporal, hippocampal, and prefrontal regions in the neuroanatomy of impulsivity.