What are the neurocognitive mechanisms that contribute to antisocial behaviors? A study in Brain imaging and behavior suggests that decreased white matter connectivity may be linked to psychopathy in incarcerated women.
People who display high levels of psychopathy often exhibit manipulative behavior and lack empathy, guilt, and remorse. These traits may be linked to antisocial and criminal behavior. Much of the research on psychopathy has focused on males, in part because psychopathy is more common in males, including when examining incarcerated samples.
Research including both genders has shown many sex differences between male and female psychopaths, including that males exhibit higher levels of perversion and more frequent antisocial behaviors associated with psychopathy. High levels of psychopathy have been associated with several different neurological factors, including reduced gray matter volume and reduced amygdala activity when processing frightened facial expressions.
It has been suggested that the uncinate tract, which is a white matter tract connecting the orbitofrontal cortex and the amygdala, may play a role in psychopathy. Previous research has shown weakening of the unciform tract in boys and men with higher levels of psychopathy. Additionally, the unciform tract has been implicated in the regulation of emotional responses and the ability to understand and interpret the emotional states of others, both of which are impaired in people with psychopathy.
In their new study, Michael Maurer and his colleagues sought to expand the body of research by testing whether it extends to women. They used 254 incarcerated adult women between the ages of 19 and 54. 81% of the sample identified as white, 90% of the sample were right-handed, and 56% of the participants identified as Hispanic.
Participants completed a semi-structured interview to assess psychopathy and completed a measure on substance use severity as a possible covariate. To assess brain structure, participants performed MRI with diffusion tensor imaging.
The results showed that lifestyle and behavioral psychopathic traits were associated with reduced fractional anisotropy (which measures white matter connectivity) in left and right uncinate fascicles. The only other factor that showed significant associations with fractional anisotropy in the uncinate bundle was age, as substance use, interpersonal, affective, and antisocial psychopathic traits had no significant relationships.
This suggests that traits such as impulsivity, irresponsibility, and boredom were related to reduced connectivity in the uncinate bundle, but interpersonal psychopathic factors may not. These results show that the unciform tract likely plays a role in psychopathy in both males and females.
“The results obtained in the present study help to better characterize the structural abnormalities associated with women with a high score of psychopathy,” the researchers wrote. Specifically, while boys and men scoring high on interpersonal/affective psychopathic traits have previously been associated with reduced reductions (uncinate bundle fractional anisotropy) and (gray matter volume), these relationships appear to be motivated by lifestyle/behavioral traits in girls and women score high on psychopathy.
This study provides insight into the brain mechanisms underlying psychopathy in women. Despite this, there are limitations to note. One such limitation is that this study did not control for symptomatology of borderline personality disorder, which overlaps with psychopathy and has been linked to reduced connectivity in the uncinate bundle. Moreover, the use of fractional anisotropy provides only an indirect measure of white matter connectivity.
The study, “Reduced structural integrity of the uncinate bundle in incarcerated women with a high psychopathy score,” was authored by J. Michael Maurer, Subhadip Paul, Bethany G. Edwards, Nathaniel E. Anderson, Prashanth K. Nyalakanti, Carla L. Harenski, Jean Decety, and Kent A. Kiehl.