Brain Regions Influencing Implicit Violent Attitudes: A Lesion-Mapping Study.

Area of Science:

• Neuroscience
• Psychology
• Traumatic Brain Injury Research

Background:

• Aggression is a common and persistent issue following traumatic brain injuries (TBIs).
• Existing research often measures explicit aggression, which may not reflect true underlying tendencies.
• Dysfunction in the prefrontal and temporal cortex is associated with maladaptive aggression.

Purpose of the Study:

• To investigate the neural basis of implicit attitudes toward aggression using a modified Implicit Association Task (IAT).
• To examine the causal contribution of specific brain areas to implicit attitudes toward violence.
• To explore the role of executive functions in regulating implicit attitudes toward aggression.

Main Methods:

• Utilized a modified Implicit Association Task (IAT) in a unique sample of 112 Vietnam War veterans with penetrating brain injuries.
• Included 33 healthy combat veterans without brain injury as controls.
• Employed voxel-based lesion-symptom mapping to identify brain structures underpinning implicit aggression.

Main Results:

• Individuals with lesions to the dorsolateral prefrontal cortex (dlPFC) and inferior posterior temporal cortex (ipTC) exhibited a more positive implicit attitude toward aggression.
• Executive functions were found to be critically involved in regulating implicit attitudes toward violence and aggression.
• Findings complement existing research on explicit aggression, which is centered on the ventromedial prefrontal cortex.

Conclusions:

• Damage to the dlPFC causally influences implicit attitudes toward violence, leading to a more positive bias.
• The dlPFC and ipTC play a significant role in modulating implicit attitudes about violence and aggressive behavior.
• Cognitive behavioral therapies targeting cognitive control, dependent on an intact dlPFC, may be effective in treating aggressive and violent behaviors.