The concept of psychopathy refers to a constellation of personality traits and behaviours characterised by a lack of remorse, a lack of emotionality, impulsivity, and poor decision making. In turn, the concept is linked to antisocial behaviour, violence, and poor treatment prognosis (Hare & Neumann, 2008). The link between psychopathy and possible frontal lobe dysfunction arose from observations of similarities between individuals with acquired frontal lobe damage and those with psychopathy (Harlow, 1848).
Neuropsychological investigations of psychopathy have often, however, shown no sign of executive function impairment (e.g., Hare, 1984 and Hart et al., 1990). The reasons for this may be manifold but there appears to be an emerging theory that tasks that are associated with the function of the orbitofrontal cortex (OFC) are compromised in psychopaths, whereas those that are associated with dorsolateral prefrontal cortex (DLPFC) are unaffected. Lapierre, Braun, and Hodgins (1995) showed that tests associated with OFC function (Go/NoGo task; Porteus Maze Test) produced large differences between psychopathic and control offender groups, whilst those associated with DLPFC function (Wisconsin Card Sort Test) did not. Blair et al. (2006) examined the spatial alternation (SA) task and the object alternation task (OA) in psychopaths. These two tasks appear very similar as both involve using the previous response to guide response selection on the next trial. Nevertheless, the OA appears to require intact OFC function, whilst the SA requires intact DLPFC function (Mishkin, Vest, Waxler, & Rosvold, 1969). In line with the OFC deficit hypothesis, psychopaths showed increased errors on the OA task but not the SA task (see also Mitchell, Colledge, Leonard, & Blair, 2002).
A common concern in the study of adult individuals with psychopathy is that their lifestyle, which often includes a range of risk and sensation seeking behaviours, may be responsible for differences in brain function and/or executive function. In particular, the excess use of drugs and alcohol can alter executive function, including many of the tasks mentioned above as providing evidence in support of the OFC deficit hypothesis (Bolla et al., 2003 and Reay et al., 2006). Therefore, studies of sub-clinical levels of psychopathic traits within community samples may be able to provide “paralleling evidence” to studies of clinical psychopathy. However, to date, there have been few studies that have tested neuropsychological functioning of sub-clinical psychopathy. We have taken a small battery of tests that have been shown to be related to clinically defined psychopathy and tested to see if performance is related to self-reported psychopathy in a sample of college students. It is also expected that the effects of chronic drug or alcohol abuse may be less likely to be present than a clinical sample. In Experiment 1 we looked at the Object and the spatial alternation tasks, whilst in Experiment 2 we looked at the Porteus Maze task.
There is also increasing recognition that psychopathy at a global level is underpinned by a small number of factors, yet there is little data that has addressed which aspects of psychopathy may be related to which neuropsychological dysfunction. The Psychopathic Personality Inventory – Revised (PPI-R; Lilienfeld & Widows, 2005) produces a global psychopathy score and assesses the traits of Fearless Dominance (which involves social potency, immunity to stress, and fearlessness), Self-Centered Impulsivity (which involves impulsiveness, lack of planning, and blame externalisation), and Coldheartedness (which involves a lack of emotion). The questionnaire was developed to place greater emphasis on the personality traits related to psychopathy as compared to the often used clinical measure of psychopathy, the Psychopathy Checklist – Revised (PCL-R; Hare, 2003). The dimensions of Fearless Dominance and Self-Centered Impulsivity have been equated to the PCL-R factors 1 (Interpersonal/Affective) and 2 (Lifestyle/Antisocial) (see Rilling et al., 2007), however other authors have not found a close match between these two conceptualisations of psychopathy (Copestake et al., 2011, Hughes et al., 2013 and Marcus et al., 2013).
