Psychopathy, executive functions, and neuropsychological data: a response to Sifferd and Hirstein.

The issue whether psychopathic offenders are practically rational has attracted philosophical attention. The problem is relevant in theoretical discussions on moral psychology and in those concerning the appropriate social response to the crimes of these individuals. We argue that classical and current experiments concerning the instrumental learning in psychopaths cannot directly support the conclusion that they have impaired instrumental rationality, construed as the ability for transferring the motivation by means-ends reasoning. In fact, we defend the different claim that these experiments (...) appear to show that psychopaths in certain circumstances are not aware of the relevant means for their ends. Moreover, we suggest how further empirical research could help to settle the issue. (shrink)

Deficits in reinforcement learning are presumed to underlie the impulsive and incorrigible behavior exhibited by psychopathic criminals. However, previous studies documenting reversal learning impairments in psychopathic individuals have not investigated this relationship across a continuous range of psychopathy severity, nor have they examined how reversal learning impairments relate to different psychopathic traits, such as the interpersonal-affective and lifestyle-antisocial dimensions. Furthermore, previous studies have not considered the role that childhood maltreatment and substance use may have in this specific cognitive deficit. Using (...) a standard reversal learning task in a sample of N = 114 incarcerated male offenders, we demonstrate a significant relationship between psychopathy severity and reversal learning errors. Furthermore, we show a significant interaction between psychopathy and childhood maltreatment, but not substance use, such that individuals high in psychopathy with an extensive history of maltreatment committed the greatest number of reversal learning errors. These findings extend the current understanding of reversal learning performance among psychopathic individuals, and highlight the importance of considering childhood maltreatment when studying psychopathy. (shrink)

We argue that philosophy has an important role to play in bridging certain social practices with certain scientific advancements. Specifically, we describe such a role by focusing on the issue of how and whether neuropsychological data concerning psychopathic offenders reflect on their criminal culpability. We offer some methodological requirements for this type of philosophical application. In addition, we show how it might help in addressing the problem of determining the criminal responsibility of psychopathic offenders.

Background Men with antisocial personality disorder show lifelong abnormalities in adaptive decision making guided by the weighing up of reward and punishment information. Among men with antisocial personality disorder, modifi cation of the behaviour of those with additional diagnoses of psychopathy seems particularly resistant to punishment. Methods We did a case-control functional MRI (fMRI) study in 50 men, of whom 12 were violent off enders with antisocial personality disorder and psychopathy, 20 were violent off enders with antisocial personality disorder but (...) not psychopathy, and 18 were healthy non-off enders. We used fMRI to measure brain activation associated with the representation of punishment or reward information during an event-related probabilistic response-reversal task, assessed with standard general linear-model-based analysis. Findings Offenders with antisocial personality disorder and psychopathy displayed discrete regions of increased activation in the posterior cingulate cortex and anterior insula in response to punished errors during the task reversal phase, and decreased activation to all correct rewarded responses in the superior temporal cortex. This finding was in contrast to results for off enders without psychopathy and healthy non-off enders. Interpretation Punishment prediction error signalling in off enders with antisocial personality disorder and psychopathy was highly atypical. This finding challenges the widely held view that such men are simply characterised by diminished neural sensitivity to punishment. Instead, this fi nding indicates altered organisation of the information processing system responsible for reinforcement learning and appropriate decision making. This difference between violent offenders with antisocial personality disorder with and without psychopathy has implications for the causes of these disorders and for treatment approaches. (shrink)