People with violent psychopathy exhibit psychopathic spectrum brain characteristics that are similar to well-functioning adults with asocial personality features, according to a study published in Cerebral Cortex.
Because psychopathy predicts criminal behavior and violence, the researchers in this recent study completed in Finland wanted to see if psychopathy has an organic basis.
The researchers performed MRI imaging on 100 well-functioning individuals, 19 violent male offenders, and 19 matched controls. The subjects all watched videos that displayed violent and non-violent content during the MRIs.
Offenders with psychopathic traits had significantly lower grey matter density (GMD) in the anterior insula, orbitofrontal cortex (OFC) and secondary somatosensory cortex (SII), which indicated atrophy in these regions, the researchers reported. No regions showed significant associations with primary psychopathy.
When watching violent movie scenes, the offenders experienced heightened activation in OFC, bilateral insula, anterior and middle cingulate cortices, thalamus, and superior and middle temporal polysensory regions. The brain responses were comparable to what was observed in the community sample.
Limitations include traits being assessed using self-reports. The researchers said it was not possible to recruit a completely medication-free sample of criminal offenders. The convicted offenders and community group had different levels of social interaction and leisure activities. Also, the isolated movie clips are not reflective of the real world.
The researchers concluded, “integrity and function of the frontal and insular cortex associate with both extreme and benign variations of antisocial behavior, providing neurobiological support for a common neural basis of antisocial behaviors with different severity.”
Reference Nummenmaa L, Lukkarinen L, Sun L, et al. Brain basis of psychopathy in criminal offenders and general population. Cereb Cortex. Published online April 9, 2021. doi:10.1093/cercor/bhab072