Irving B. Harris Professor of Psychology and Psychiatry
The University of Chicago
5848 S. University Ave.
Chicago, IL 60637 – USA
Faculty Web page: http://psychology.uchicago.edu/people/faculty/jdecety.shtml
SCNL Web page: www.scnl.org
Child NeuroSuite: www.childneurosuite.org
MedicalResearch.com: What are the main findings of the study?
Dr. Decety: In our study, psychopaths exhibited significantly less activation in the ventromedial prefrontal cortex, lateral orbitofrontal cortex, and brainstem relative to controls, but surprisingly showed greater activation in the insula. The major difference in brain response between psychopaths compared to controls during the perception of others in pain was the lack of engagement of regions in the brainstem, orbitofrontal cortex (OFC) and ventromedial prefrontal cortex (vmPFC).
Consistent with previous studies we found that psychopaths have a dysfunction in the vmPFC/OFC –a critical region that supports the integration of emotional responses with moral decision making- which contributes to their moral insensitivity and lack of empathic responses.
MedicalResearch.com: Were any of the findings unexpected?
Dr. Decety: Yes, we did not anticipate a response of the insula, which was greater in psychopaths as compared to controls. The insula has been reliably reported in all the neuroimaging studies of empathy for pain in healthy participants, and interpreted as playing a pivotal role in emotional awareness. So if we want to interpret our results in line with these previous studies, then we have to admit that psychopaths are emotionally “aware” of the pain/distress of others, but this signal does not register in other regions of the brain such as the orbitofrontal cortex, and this contributes to their insensitivity to others and lack of concern for their well-being.
Another possible interpretation is the “response modulation hypothesis”, which suggests that deficits in the processing of emotional information by psychopaths may be attributable to problems in switching attention to stimuli with emotional salience or peripheral stimuli in general. There is evidence that individuals with psychopathy may show up-regulate emotional processing (at least for fear) when attention to salient stimuli is particularly engaged. In our case, watching the visual stimuli in the scanner, which are very salient, may have drawn their attention to even a greater degree than the controls. This latter interpretation is further compatible with the view that insula and anterior cingulate cortex (also activated in psychopaths) form the core of a network that facilitates the detection of important environmental stimuli.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Decety: The atypical processing of negative emotional stimuli, such as perceiving others suffering or in pain, which is an important source for empathic concern, coupled with poor inhibitory control, may account for morally inappropriate behavior in psychopaths. Evidence for such deficiencies is found not only in behavior, but also at the neural level of analysis. Dysfunction of the connectivity between the amygdala and vmPFC seems to partially explain low socio-emotional responses to others’ distress, though it is important to note that a lack of empathic arousal alone does not explain offensive behaviors. Behavior is motivated by rewards and discouraged by punishments, with the former influencing behavior more effectively than the latter in most individuals. Offending behavior exists and persists because it is rewarding, and these rewards in turn affect the activity of the mesolimbic dopamine system. We need to engage in more research to better understand what motivates criminal behavior. I need to add that, not all psychopaths are criminals, nor all criminals are psychopaths!
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Decety: To elucidate what are the dysfunctions in the brain of psychopaths, structural MRI, anatomical connectivity, and genetics are critical to be combined with very large samples, and possibly different sites in the US and outside as well.
MedicalResearch.com: How does this study differ and build on earlier work?
There have been many studies on psychopathy, but most of them are done on very small sample size and as a result lack power.
Second none of the previous studies have examined such a simple and yet critical condition such as how do individuals with psychopathy react to perceiving other people in pain or distress. Besides, there is an amazing heterogeneity of the results in the domain of empathy, which are not only due to small sample size but on how psychopathy is defined and measured.
Given that perceiving pain in others is usually a very strong signal that triggers empathy and that healthy individuals are predisposed (outside a competitive context of course) to find the distress of others aversive and learn to avoid actions associated with this distress, studying how psychopaths react to such signal is extremely important.
Empathy shapes the landscape of our social and moral lives. It can motivate helping others in distress; it plays an essential role in inhibiting aggression, and it facilitates cooperation between members of a similar species. Thus, understanding individuals who lack this basic natural ability (that we share with many species) is critical.
Brain Response to Empathy-Eliciting Scenarios Involving Pain in Incarcerated Individuals With Psychopathy.
Decety J, Skelly LR, Kiehl KA.
JAMA Psychiatry. 2013 Apr 24:1-8. doi: 10.1001/jamapsychiatry.2013.27.
[Epub ahead of print]