New research provides insight into the neurobiological mechanisms underlying certain psychopathic tendencies. The study, published in NeuroImage: Clinical, indicates that psychopathic personality traits such as callousness are associated with differences in connectivity between two important brain networks.
“We are broadly interested in understanding psychopathy, a harmful set of personality traits that is associated with severe aggression, criminality, and recidivism,” said study author Hailey Dotterer, a doctoral candidate in psychology at the University of Michigan.
“We’ve been curious about what motivates people to act the way they do, particularly when individuals act in negative ways — in harming others and ignoring societal norms and laws, which is essentially the core of psychopathy.”
“It is important to investigate the neural underpinnings of psychopathy because previous work suggests that the ways that disparate brain regions communicate with each other is related to emotion and attention, which are impaired in psychopathy,” Dotterer said.
Dotterer and her colleagues examined resting-state functional magnetic resonance imaging (fMRI) data from 123 men who had completed an assessment of psychopathic personality traits. These traits were measured on a continuum and in the community, meaning they measured the relative amount of these traits in young adults, not in those in prisons or classified as psychopaths. That is, we all have relatively more or less of each of these traits and these can be mapped to brain functioning.
The researchers also used an algorithm known as Group Iterative Multiple Model Estimation to create person-specific connectivity maps for each participant.
“Psychopathy and psychopathic traits look different in different people. Some people are more superficially charming and manipulative, and other people are more impulsively aggressive. This means that it is important to consider individuals in research on psychopathy in order to ultimately inform personalized intervention approaches,” Dotterer told PsyPost.
“Traditionally, within neuroimaging studies, all participants in a group are essentially assumed to have similar brain networks; sometimes this is true, but when it’s not, results may not be accurate. Our approach doesn’t make this assumption” echoed study author Adriene Beltz, an assistant professor of psychology at the University of Michigan.
Despite the unique brain structure of each participant, the researchers found a common pattern of connectivity among those with relatively higher levels of psychopathic traits. Those participants with higher levels of traits tended to have increased density in connections between the brain’s default mode network and the central executive network.
The default mode network is involved in social cognition and moral reasoning, while the central executive network is involved in self-control and appraisal of threatening stimuli.
“We found that psychopathic traits, particularly traits of remorselessness and lack of empathy, were associated with increased communication between two brain networks that are typically ‘anti-correlated’, generally meaning when one is on, the other is off: the default mode network and central executive network,” Dotterer and Beltz explained.
“Increased communication between these networks could interfere with the typical functions of these networks, impacting behaviors like decision-making and perspective-taking, which we know are impaired in individuals with psychopathic traits.”
“Of course, one issue to consider is that these are traits measured in young adults in the community, none of whom were tested for clinical levels of psychopathy. Thus, the results tell us about the brain correlations of lower levels of these traits we see in the community.”
The study also highlighted the limitations of traditional approaches to analyzing fMRI data.
“These young men all had unique brain networks — so unique that there wasn’t any one connection between brain regions that was common to all participants,” Beltz told PsyPost. “Accurate modeling of brain networks is essential to understanding how the brain is related to things like personality traits or behavior.”
But, Dotterer noted, it is still unclear how the observed patterns of brain connectivity translate into behavior. “We now think the patterns are related to some psychopathic traits, but do they actually drive the behaviors we associate with those traits, such as difficulties empathizing with other people?”
“We need more developmental and longitudinal research to better understand where these traits and brain patterns come from, that is, whether brain network functioning predicts psychopathic traits, or vice versa. We also need to see if these findings emerge in prison populations and in people with higher levels of these traits.” Dotterer said.
The study, “Connections that characterize callousness: Affective features of psychopathy are associated with personalized patterns of resting-state network connectivity“, was authored by Hailey L. Dotterer, Luke W. Hyde, Daniel S. Shaw, Emma L. Rodgers, Erika E. Forbes, and Adriene M. Beltz.