Differentiating among prefrontal substrates in psychopathy: Neuropsychological test findings.

Abstract

Frontal lobe and consequent executive dysfunction have long been related to psychopathy. More recently, there have been suggestions that specific regions of frontal cortex, rather than all of frontal cortex, may be implicated in psychopathy. To examine this issue, the authors presented 25 individuals with psychopathy and 30 comparison individuals with measures preferentially indexing the orbitofrontal cortex (OFC; object alternation task), dorsolateral prefrontal cortex (DLPFC; spatial alternation task), and anterior cingulate cortex (ACC; number-Stroop reading and counting tasks). The individuals with psychopathy showed significant impairment on the measure preferentially sensitive to OFC functioning. In contrast, the 2 groups did not show impairment on the measures preferentially sensitive to the functioning of the DLPFC or ACC. These results are interpreted with reference to executive dysfunction accounts of the disorder.

Reversal deficits in individuals with psychopathy in explicit but not implicit learning conditions

“…However, there are also studies that used different behavioural measures and reported unaffected cognitive control in individuals with psychopathy. 35,36 These studies point out that not all aspects of cognitive control are compromised or that different behavioural indexes vary in sensitivity and suitability depending on the function being assessed. For instance, Blair and colleagues 35 used a series of neuropsycho logical tests, each known to be sensitive to different executive functions, in different cortical areas.…”

“…35,36 These studies point out that not all aspects of cognitive control are compromised or that different behavioural indexes vary in sensitivity and suitability depending on the function being assessed. For instance, Blair and colleagues 35 used a series of neuropsycho logical tests, each known to be sensitive to different executive functions, in different cortical areas. Their results indicated that the psychopathy group did not show deficiencies on behavioural measures preferentially sensitive to functions of the anterior cingulate and dorsolateral prefrontal cortex, whereas measures quantifying functions of the OFC did show deficiencies.…”

No clear evidence for a positive association between the interpersonal-affective aspects of psychopathy and executive functioning

“…Except for two studies (Hansen et al, 2007, andBlair et al, 2006), all studies controlled for the effect of potentially relevant confounding or mediating factors, although the specific content of those factors greatly differed across the studies. Finally, in 6 studies using zero-order correlations and/or simple ANOVAs, there was no control for the effect of the correlation between Factors 1 and 2, when assessing the association between Factor 1 and EF components.…”

Some dychotomous classifications of aggression according to its function

“…According to Barratt et al (1997), the parietal lobe would function less efficiently, while the also highly serotonergically innervated frontal lobe would possibly be more related to antisocial behaviour. Other researchers, however, observed that impulsive aggression patients was significantly associated with blunted metabolic responses in orbital frontal, adjacent ventral medial and cingulate cortex, but not in the inferior parietal lobe (Siever et al, 1999;Soloff et al 2000;Blair et al, 2006).…”

“…Whereas patients with acquired sociopathy show an impairment of the frontal lobe ) and their aggression is exclusively of an impulsive nature (Anderson et al 1999;Grafman et al 1996), a heightened level of premeditate aggression is found exclusively in another form of antisocial personality known as psychopathy, characterized by an increased risk of both impulsive and instrumental aggression (Blair 2006;Blair et al 2006;Hare 2001). Proceeding from the consideration that 'cold' instrumental aggression is accompanied by deficits in learning social rules about avoiding antisocial behaviour, the hypothesis was advanced that a dysfunction of the amygdala, a structure important for emotional learning, is primarily connected with psychopathy (Blair 2001(Blair , 2003.…”