What are the neurocognitive mechanisms that contribute to antisocial behaviors? A study in Brain Imaging and Behavior suggests that decreased white matter connectivity could be linked to psychopathy for incarcerated women.
Individuals who display high levels of psychopathy often engage in manipulative behavior and have a lack of empathy, guilt, and remorse. These traits can be linked to antisocial and criminal behavior. Much of the research on psychopathy has been focused on men, in part due to the fact that psychopathy is more common in men, including when looking at incarcerated samples.
Research including both genders has displayed many sex differences between male and female psychopaths, including that men show higher levels of perversion and more frequent antisocial behavior associated with psychopathy. High levels of psychopathy has been associated with several different neurological factors, including reduced gray matter volume and reduced amygdala activity when processing scared facial expressions.
It has been suggested that the uncinate fasciculus, which is a white matter tract connecting the orbitofrontal cortex and amygdala, may play a role in psychopathy. Previous research has shown a weakening of the uncinate fasciculus in boys and men with higher levels of psychopathy. Additionally, the uncinate fasciculus has been implicated in the regulation of emotional responses and the ability to understand and interpret the emotional states of others, which are both impaired in individuals with psychopathy.
In their new study, Michael Maurer and colleagues sought to expand the body of research by testing if this extends to women. They utilized 254 incarcerated adult women ranging in age from 19 to 54-years-old. 81% of the sample identified as White, 90% of the sample was right-handed, and 56% of participants identified as Hispanic.
The 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, the participants completed an MRI with diffusion tensor imaging.
Results showed that lifestyle and behavioral psychopathic traits were associated with reduced fractional anisotropy (which measures white matter connectivity) in both the left and the right uncinate fasciculus. The only other factor that showed significant associations with fractional anisotropy in the uncinate fasciculus was age, as substance use, interpersonal, affective, and antisocial psychopathic traits did not have any significant relationship.
This suggests that traits such as impulsivity, irresponsibility, and boredom were related to the lowered connectivity in the uncinate fasciculus, but interpersonal psychopathic factors may not be. These results show that the uncinate fasciculus likely plays a role in psychopathy for both men and women.
“The results obtained in the current study help better characterize structural abnormalities associated with women scoring high on psychopathy,” the researchers wrote. “Specifically, while boys and men scoring high on interpersonal/affective psychopathic traits have been previously associated with reduced [uncinate fasciculus fractional anisotropy] and [gray matter volume] reductions, such relationships appear to be driven by lifestyle/behavioral traits in girls and women scoring 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 borderline personality disorder symptomology, which overlaps with psychopathy and has been linked to reduced connectivity in the uncinate fasciculus. Additionally, using fractional anisotropy provides only an indirect measure of white matter connectivity.
The study, “Reduced structural integrity of the uncinate fasciculus in incarcerated women scoring high on psychopathy“, 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.