Making up approximately 1% of the U.S population and up to 20% of the country’s prison population, psychopath and criminals with psychopathic traits is a major focus in both the legal system and neuroscience research. Many studies have already been conducted on the brains of psychopaths in hopes of elucidating clues about the causes of their antisocial behaviors. According to one review by Blair, it has been previously revealed that psychopaths exhibit increased levels of proactive and reactive aggression. Furthermore, through fMRI studies it has been found that people with psychopathic traits often have reduced amygdala and orbito-frontal cortex activities. While it has been shown that the activities in these brain regions are reduced in psychopaths, the actual physical difference that causes these reductions has yet to be presented.
However, recently a new study conducted by Newman et al reveals decreased physical connections between the amygdala and the ventromedial prefrontal cortex (vmPFC). Amygdala is critical in mediating fear and anxiety while the vmPFC is responsible for “sentiments such as empathy and guilt.” Combined, the lessened connection leads to a lower activity by these brain regions that may explain the antisocial impulses displayed by psychopaths. The researchers of this study utilized a diffusion tension imaging device (DTI) and compared results between 20 psychopathic prisoners and 20 non-psychopathic prisoners that committed similar crimes. Results revealed a “reduction in structural integrity of white matter fibers” that connects the two brain regions. Additionally, an fMRI scan was performed. Similar to previous findings, researchers found less coordinated activities. This study is perhaps the first to present both structural and functional differences in the brains of a psychopath. According to Dr. Koenigs of the research team, these results indicate that there is “a specific brain abnormality that is associated with criminal psychopathy.”
With these findings, the researchers at University of Wisconsin-Madison hope to shed more light on the source of the dysfunction and future strategies in treating psychopathy. Furthermore, the researchers discuss the legal implications of their findings. They question whether the legal system can hold psychopaths as accountable as someone that does not have a brain abnormality. I believe while the legal system should react to psychopaths differently, they should not be forgiven solely base off of brain differences. It is still necessary to take them off the streets if they committed a serious crime. However, perhaps the more appropriate long term response is to employ rehabilitation and treatments rather than incarcerations and punishments.