Structural variation of the insula and psychopathic traits: a community sample study

Abstract

Psychopathy is a personality disorder marked by deficit in emotional processing, antisocial behavior, interpersonal manipulation and impulsive and erratic lifestyle. Functional and structural imaging studies have been used for analyses in cortical thinning and volume of grey and white matter in brain structures to identify the underlying abnormalities in psychiatric disorders. Previous studies indicate that individuals with psychopathy show an impaired response in the insula when processing emotional information, and this has been hypothesized to contribute to their callous-unemotional behavior. In parallel, it has also been found that these individuals display structural alterations in this region. Psychopathy is regarded as a dimensional construct and evidence points to continuities in the neurocognitive mechanisms that underlie the disorder. However, it is yet unknown whether the functional and structural abnormalities found in clinical and forensic samples can also be verified in subclinical groups or even if the same impaired processes are applied. Furthermore, it is still uncertain if the structural variation associated with psychopathic traits contribute to the etiology of the disorder or not. The objective of this study was to test if the same pattern of insula structural alterations was associated with the variance in psychopathic traits in the general population. Using a community sample (n=58) and measures of grey matter and white matter computed of T1 MRI data, our results show that the grey matter volume in the right insula and the white matter volume bilaterally is negatively associated with several psychopathic traits, indicating continuities in the neuro correlates of this disorder.