Several researchers, such as Adrian Raine, have done work studying the brains and neurological responses of children who exhibit traits often found in psychopaths and today we look at another such researcher.

Abigail Marsh is an assistant professor of psychology at Georgetown University who directs the school’s Laboratory on Social and Affective Neuroscience. This lab uses cognitive neuroscience methods to explore, among other things, the roots of empathy.

Marsh’s path to interest in this topic is, as is true for many of us who have been drawn to it, a compelling one. As she explains in her profile on her lab’s website, when she was 20 years old, she was in an accident, after which a stranger saved her life. And, as she explains in another interview, a few years later, a different stranger punched her in the face, breaking her nose.

Events like these led her to wonder why some people help others and some harm others. Her quest for answers led her to earn a Ph.D. in Social Psychology from Harvard and to do post-doctoral work with James Blair, another leader in the field who has done great work on these subjects.

As described by Georgetown University News, Marsh’s latest research – which also involved the National Institutes of Health, the Center for Disease Control and Prevention and several other researchers including Blair – showed that “young people with conduct problems and psychopathic traits such as callousness and remorselessness show less activity in the regions of the brain associated with empathy.”

Specifically, functional magnetic resonance imaging (fMRI) was used to measure brain activity as two different groups of adolescents looked at photographs of other people experiencing pain-inducing injuries while imagining either that the body in the photo was their own or someone else’s.

The first group consisted of adolescents with both:

• Psychopathic Traits
• Conduct Disorder or Oppositional Defiant Disorder

The second group was a control group of youngsters of matched age, gender and intelligence.

The study found that:

• As the injuries depicted became more painful, the youngsters with psychopathic traits showed reduced activity in the rostral anterior cingulate cortex, ventral striatum (putamen), and amygdala, all of which are brain regions associated with the experience of empathic pain.
• Amygdala activity was especially reduced when perceiving the injury as happening to another person rather than oneself.
• Youngsters whose scores on the PCL:YV (the Youth Version of the Hare Psychopathy Checklist) were higher, indicating more severe psychopathic traits, showed less activity in the amygdala and rostral anterior cingulate cortex, specifically.

The researchers also discovered that, in the group with psychopathic traits, lower responsiveness was predictive of psychopathic symptom severity.

The formal title of the study is “Empathic responsiveness in amygdala and anterior cingulate cortex in youths with psychopathic traits.” It is published in the March 12, 2013 issue of the Journal of Child Psychology and Psychiatry.

In the Georgetown University News piece, Abigail Marsh says that, in her future work, she hopes to help tease out even more fully the various types of different mechanisms underlying helpful and harmful behavior. She explains, “I will continue to use brain imaging, genetic and behavioral research paradigms in healthy adults and adolescents as well as adolescents with conduct problems to try to understand the origins of empathy, aggression, and altruism.” Such important goals position her work squarely in the realm of ponerology.

When I wrote my detailed page about psychopathy, I made sure to include information about some of these biological differences. Many of them have to do with the ways in which psychopaths’ brain structure and function diverge from that of others.

Recently, a new study was published adding to this important and growing mass of findings.

A team from Italy used MRI to compare the morphology of three brain areas – the caudate, putamen and nucleus accumbens – in offenders scoring medium-high on the Psychopathy Checklist, Revised to those in healthy controls. They found that the offenders had significantly different morphology of the caudate and putamen and a significantly smaller volume in the nucleus accumbens.

The findings were published in “Atypical nucleus accumbens morphology in psychopathy: Another limbic piece in the puzzle” in The International Journal of Law and Psychiatry.

As important as these and related findings are, they still fail to answer another crucial question: Are psychopaths innately genetically endowed with these differences or do they acquire them either in utero or at some other point during development? If we are able to learn more about the answers to that question, the implications could become even more profound.