Lack of correspondence between the reactive proactive questionnaire and the impulsive premeditated aggression scale among forensic psychiatric outpatients.

The most studied bimodal classifications of aggressive behavior are the impulsive/premeditated distinction measured with the Impulsive Premeditated Aggression Scale and the reactive/proactive distinction measured with the Reactive Proactive Questionnaire. The terms of these classifications are often used interchangeably, assuming that reactive aggression is equivalent to impulsive aggression and that proactive aggressive behavior is the same as premeditated aggression. The correspondence or discrepancy between both aggression classifications/questionnaires, however, is understudied. Therefore, the current study investigated the correspondence between the RPQ and IPAS in a sample of 161 forensic psychiatric outpatients (FPOs) with severe aggressive behavior. Correlation analysis revealed a limited correspondence between the RPQ and IPAS. Cluster analyses derived three clusters from the RPQ as well as the IPAS: these clusters did not match in 60.3% of the cases. Furthermore, the notion that the RPQ measures trait aggression whereas the IPAS assesses state aggression could not be verified. The present study indicates that aggression subtypes as measured by use of the RPQ and IPAS correspond only partially and should not be used interchangeably. Furthermore, it was suggested that RPQ focuses more on actual aggressive behavior and the IPAS more on emotions and their regulation. Future research is needed to elucidate the applicability of both questionnaires in further detail.

Psychopathic tendency in violent offenders is associated with reduced aversive Pavlovian inhibition of behavior and associated striatal BOLD signal.

Background: Violent offenders with psychopathic tendencies are characterized by instrumental, i.e., planned, callous, and unemotional (aggressive) behavior and have been shown to exhibit abnormal aversive processing. However, the consequences of abnormal aversive processing for instrumental action and associated neural mechanisms are unclear. Materials and methods: Here we address this issue by using event-related functional magnetic resonance imaging (fMRI) in 15 violent offenders with high psychopathic tendencies and 18 matched controls during the performance of an aversive Pavlovian-to-instrumental transfer paradigm. This paradigm allowed us to assess the degree to which aversive Pavlovian cues affect instrumental action and associated neural signaling. Results: Psychopathic tendency scores were associated with an attenuation of aversive Pavlovian inhibition of instrumental action. Moreover, exploratory analyses revealed an anomalous positive association between aversive inhibition of action and aversive inhibition of BOLD signal in the caudate nucleus of violent offenders with psychopathic tendencies. In addition, psychopathic tendency also correlated positively with amygdala reactivity during aversive versus neutral cues in Pavlovian training. Conclusion: These findings strengthen the hypothesis that psychopathic tendencies in violent offenders are related to abnormal impact of aversive processing on instrumental behavior. The neural effects raise the possibility that this reflects deficient transfer of aversive Pavlovian inhibitory biases onto neural systems that implement instrumental action, including the caudate nucleus.

Neural connectivity during reward expectation dissociates psychopathic criminals from non-criminal individuals with high impulsive/antisocial psychopathic traits.

Criminal behaviour poses a big challenge for society. A thorough understanding of the neurobiological mechanisms underlying criminality could optimize its prevention and management. Specifically,elucidating the neural mechanisms underpinning reward expectation might be pivotal to understanding criminal behaviour. So far no study has assessed reward expectation and its mechanisms in a criminal sample. To fill this gap, we assessed reward expectation in incarcerated, psychopathic criminals. We compared this group to two groups of non-criminal individuals: one with high levels and another with low levels of impulsive/antisocial traits. Functional magnetic resonance imaging was used to quantify neural responses to reward expectancy. Psychophysiological interaction analyses were performed to examine differences in functional connectivity patterns of reward-related regions. The data suggest that overt criminality is characterized, not by abnormal reward expectation per se, but rather by enhanced communication between reward-related striatal regions and frontal brain regions. We establish that incarcerated psychopathic criminals can be dissociated from non-criminal individuals with comparable impulsive/antisocial personality tendencies based on the degree to which reward-related brain regions interact with brain regions that control behaviour. The present results help us understand why some people act according to their impulsive/antisocial personality while others are able to behave adaptively despite reward-related urges.