A cognitive neuroscience perspective on psychopathy: evidence for paralimbic system dysfunction

The neuropsychological underpinnings to psychopathic personality traits in a nationally representative and longitudinal sample

Although psychopathy is a major area of research in psychology and criminology, much remains unknown about its etiological underpinnings. Drawing on data from the National Longitudinal Study of Adolescent Health, the current study explored the association between neuropsychological deficits and psychopathic personality traits and produced three key findings. First, four neuropsychological deficits measures were consistently related to the measure of psychopathic personality traits both longitudinally and cross-sectionally. Second, neuropsychological deficits measures predicted variation in psychopathic personality traits for both males and females and the magnitude of the association between neuropsychological deficits and psychopathic personality traits did not vary as a function of gender. Third, parental socialization measures had relatively small and inconsistent effects on psychopathic personality traits. Suggestions for future research are offered.

C957T polymorphism of the dopamine D2 receptor gene is associated with motor learning and heart rate

Genetic variants that are related to the dopaminergic system have been frequently found to be associated with various neurological and mental disorders. Here, we studied the relationships between some of these genetic variants and some cognitive and psychophysiological processes that are implicated in such disorders. Two single nucleotide polymorphisms were chosen: one in the dopamine D2 receptor gene (rs6277-C957T) and one in the catechol-O-methyltransferase gene (rs4680-Val158Met), which is involved in the metabolic degradation of dopamine. The performance of participants on two long-term memory tasks was assessed: free recall (declarative memory) and mirror drawing (procedural motor learning). Heart rate (HR) was also monitored during the initial trials of the mirror-drawing task, which is considered to be a laboratory middle-stress generator (moderate stress), and during a rest period (low stress). Data were collected from 213 healthy Caucasian university students. The C957T C homozygous participants showed more rapid learning than the T allele carriers in the procedural motor learning task and smaller differences in HR between the moderate- and the low-stress conditions. These results provide useful information regarding phenotypic variance in both healthy individuals and patients.

Intrinsic limbic and paralimbic networks are associated with criminal psychopathy

BACKGROUND

Psychopathy is a personality disorder associated with impairments in decision-making, empathy, and impulsivity. Recent brain imaging studies suggest that psychopathy is associated with abnormalities in limbic/paralimbic brain regions. To date, no studies have examined functional brain connectivity measures using independent component analyses (ICA) in adults with psychopathy. Here, we test hypotheses regarding paralimbic connectivity in adult incarcerated individuals stratified by psychopathy scores.

METHODS

One hundred and two prison inmates were rated using the Hare Psychopathy Checklist-Revised (PCL-R). FMRI data were collected while subjects performed an auditory target detection "oddball" task. FMRI data were analyzed using group ICA to identify functional networks responding to the oddball task correlating with psychopathy scores.

RESULTS

Components demonstrating significant correlations with psychopathy included a default mode network, a frontoparietal component, and a visual/posterior cingulate component. Modulation trends correlated strongly with factor 2 (impulsivity) and total PCL-R scores in the frontoparietal and visual/posterior cingulate networks, and with factor 1 (affective) scores within the default mode network. The posterior cingulate region factored significantly in the modulation trends observed.

CONCLUSION

Consistent with the hypothesis of limbic/paralimbic abnormalities associated with psychopathy, modulation trends correlated strongly with PCL-R scores. There is strong evidence to implicate the posterior cingulate in aberrant functional connectivity associated with the manifestation of psychopathic symptoms. Future investigations comparing functional trends associated with the posterior cingulate in psychopathic subjects may provide further insight into the manifestation of this disorder.

Fear conditioning in psychopaths: event-related potentials and peripheral measures

Aversive pavlovian delay conditioning was investigated in a sample of 11 criminal psychopaths as identified by using the Psychopathy Checklist-Revised and 11 matched healthy controls. A painful electric stimulus served as unconditioned stimulus and neutral faces as conditioned stimuli. Event-related potentials, startle response potentiation, skin conductance response, corrugator activity, and heart rate were assessed, along with valence, arousal, and contingency ratings of the CS and US. Compared to healthy controls, psychopathic subjects failed to differentiate between the CS+/CS- as shown by an absence of a conditioned response in startle potentiation and skin conductance measures. Through use of a fear-eliciting US, these data confirm previous findings of a deficient capacity to form associations between neutral and aversive events in psychopathy that appears unrelated to cognitive deficits and is consistent with hypothesized frontolimbic deficits in the disorder.

Reduced prefrontal connectivity in psychopathy

Linking psychopathy to a specific brain abnormality could have significant clinical, legal, and scientific implications. Theories on the neurobiological basis of the disorder typically propose dysfunction in a circuit involving ventromedial prefrontal cortex (vmPFC). However, to date there is limited brain imaging data to directly test whether psychopathy may indeed be associated with any structural or functional abnormality within this brain area. In this study, we employ two complementary imaging techniques to assess the structural and functional connectivity of vmPFC in psychopathic and non-psychopathic criminals. Using diffusion tensor imaging, we show that psychopathy is associated with reduced structural integrity in the right uncinate fasciculus, the primary white matter connection between vmPFC and anterior temporal lobe. Using functional magnetic resonance imaging, we show that psychopathy is associated with reduced functional connectivity between vmPFC and amygdala as well as between vmPFC and medial parietal cortex. Together, these data converge to implicate diminished vmPFC connectivity as a characteristic neurobiological feature of psychopathy.

The psychopath magnetized: insights from brain imaging

Psychopaths commit a disproportionate amount of violent crime, and this places a substantial economic and emotional burden on society. Elucidation of the neural correlates of psychopathy may lead to improved management and treatment of the condition. Although some methodological issues remain, the neuroimaging literature is generally converging on a set of brain regions and circuits that are consistently implicated in the condition: the orbitofrontal cortex, amygdala, and the anterior and posterior cingulate and adjacent (para)limbic structures. We discuss these findings in the context of extant theories of psychopathy and highlight the potential legal and policy implications of this body of work.

Reduced susceptibility to the attentional blink in psychopathic offenders: implications for the attention bottleneck hypothesis

OBJECTIVE

Newman and Baskin-Sommers (in press) have proposed that psychopathy reflects an attention bottleneck that interferes with processing contextual information, including the timely processing of affective and inhibitory cues that initiate self-regulation. Despite a wealth of evidence that attention moderates the affective, inhibitory, and self-regulation deficits of psychopathic offenders, to date there is little or no evidence that psychopathic offenders perform abnormally on a canonical measure of selective attention. In this study, we address this gap in the literature and clarify the attention-related abnormality in psychopathy.

METHOD

We administered the attentional blink (AB) task to 37 male prisoners assessed with Hare's (2003) Psychopathy Checklist-Revised. In the AB paradigm, participants identify targets in a rapid serial visual presentation. Distracters' temporal proximity to the first target elicits a conflict between attending to the target and attending to the distracters. Greater conflict results in a larger AB (i.e., reduced accuracy for the second target).

RESULTS

As predicted, psychopathic offenders displayed a significantly smaller AB (i.e., better accuracy throughout the blink interval) than nonpsychopathic offenders.

CONCLUSIONS

Consistent with the attentional bottleneck hypothesis, psychopathic participants were less susceptible to distracter effects following presentation of an initial target. The results clarify the nature of the attention bottleneck in psychopathy, the circumstances in which it enhances versus interferes with performance, and its implications for more ecologically valid conditions involving the sequential presentation of goal-relevant and goal-incongruent information.

Reduced amygdala-orbitofrontal connectivity during moral judgments in youths with disruptive behavior disorders and psychopathic traits

We used functional magnetic resonance imaging (fMRI) to investigate dysfunction in the amygdala and orbitofrontal cortex in adolescents with disruptive behavior disorders and psychopathic traits during a moral judgment task. Fourteen adolescents with psychopathic traits and 14 healthy controls were assessed using fMRI while they categorized illegal and legal behaviors in a moral judgment implicit association task. fMRI data were then analyzed using random-effects analysis of variance and functional connectivity. Youths with psychopathic traits showed reduced amygdala activity when making judgments about legal actions and reduced functional connectivity between the amygdala and orbitofrontal cortex during task performance. These results suggest that psychopathic traits are associated with amygdala and orbitofrontal cortex dysfunction. This dysfunction may relate to previous findings of disrupted moral judgment in this population.

Aberrant paralimbic gray matter in criminal psychopathy

Psychopaths impose large costs on society, as they are frequently habitual, violent criminals. The pervasive nature of emotional and behavioral symptoms in psychopathy suggests that several associated brain regions may contribute to the disorder. Studies employing a variety of methods have converged on a set of brain regions in paralimbic cortex and limbic areas that appear to be dysfunctional in psychopathy. The present study further tests this hypothesis by investigating structural abnormalities using voxel-based morphometry in a sample of incarcerated men (N=296). Psychopathy was associated with decreased regional gray matter in several paralimbic and limbic areas, including bilateral parahippocampal, amygdala, and hippocampal regions, bilateral temporal pole, posterior cingulate cortex, and orbitofrontal cortex. The consistent identification of paralimbic cortex and limbic structures in psychopathy across diverse methodologies strengthens the interpretation that these regions are crucial for understanding neural dysfunction in psychopathy.

Attention network performance and psychopathic symptoms in early adolescence: an ERP study

Reaction time (RT) and event-related potential (ERP) measures were used to examine the relationships between psychopathic symptoms and three major attention networks (alerting, orienting, and executive attention) among a community sample of youth. Antisocial Process Screening Device (APSD; Frick and Hare 2001) total and subscale scores were negatively correlated with ERP measures of attentional alerting, indicating that youth with psychopathic symptoms had difficulty using warning cues to prepare for upcoming targets. APSD total scores were not related to performance on measures of orienting or executive attention, although weaker executive attention was found among youth with higher scores on the Impulsivity subscale. These findings support attention-based models of psychopathy and provide evidence of specific deficits in attentional alerting among youth with psychopathic traits. Deficiencies in attentional alerting may be related to noradrenergic functioning and may have cascading effects on higher order cognitive and affective processing.

A somatic marker perspective of immoral and corrupt behavior

Individuals who engage in corrupt and immoral behavior are in some ways similar to individuals with psychopathy. Normal people refrain from engaging in such behaviors because they tie together the moral value of society and the risk of punishment when they violate social rules. What is it, then, that allows these immoral individuals to behave in this manner, and in some situations even to prosper? When there is a dysfunction of somatic markers, specific disadvantageous impairments in decision-making arise, as in moral judgment, but, paradoxically, under some circumstances, the damage can cause the patient to make optimal financial investment decisions. Interestingly, individuals with psychopathy, a personality disorder, share many of the same behavioral characteristics seen in VMPFC and amygdala lesion patients, suggesting that defective somatic markers may serve as a neural framework for explaining immoral and corrupt behaviors. While these sociopathic behaviors of sometimes famous and powerful individuals have long been discussed, primarily within the realm of social science and psychology, here we offer a neurocognitive perspective on the possible neural roots of immoral and corrupt behaviors.

Joint ICA of ERP and fMRI during error-monitoring

The anterior cingulate cortex (ACC) is commonly separated into two functional divisions: the cognitive division, which lies in the caudal region and the affective division, which lies in the rostral region of the ACC. Both regions of the ACC are engaged during error-monitoring tasks; however, little is known about the temporal sequencing associated with cognition and affective processes during error-monitoring. Here we use joint Independent Component Analysis (jICA) to couple event-related potential (ERP) time courses and functional magnetic resonance imaging (fMRI) spatial maps to examine the spatio-temporal stages of engagement in the two divisions of the ACC during error-monitoring. Consistent with hypotheses, two of the five significant spatio-temporal components identified by jICA revealed that the error-related negativity (ERN) ERP was associated with distinct spatial fMRI patterns in the ACC. The ERN(1) was associated with activity in the caudal ACC and lateral prefrontal cortex (lPFC) while the ERN(2) was associated with activity in the rostral ACC. These results suggest that during error-monitoring the caudal ACC and lPFC engage prior to the rostral ACC. These results suggest that cognition precedes affect during error-monitoring.

High psychopathic trait females exhibit reduced startle potentiation and increased p3 amplitude

While there has been steady progress in identifying psychophysiological traits associated with psychopathy, most of the existing research has been carried out using incarcerated male participants, and data that include females are particularly rare. This study examined both affective startle blink modulation and P3 amplitude in a sample of female undergraduates grouped by scores on the Psychopathic Personality Inventory-Revised (PPI-R). Those scoring high for psychopathic traits lacked startle blink potentiation and demonstrated larger P3 amplitudes during auditory and visual oddball tasks. These data support the generalizability of deficient startle potentiation to non-incarcerated females with psychopathic traits, and add to a growing body of literature suggesting that psychopathic traits are associated with distinctive information-processing characteristics as indexed by P3 amplitude.

Cortex and amygdala morphology in psychopathy

Psychopathy is characterized by abnormal emotional processes, but only recent neuroimaging studies have investigated its cerebral correlates. The study aim was to map local differences of cortical and amygdalar morphology. Cortical pattern matching and radial distance mapping techniques were used to analyze the magnetic resonance images of 26 violent male offenders (age: 32±8) with psychopathy diagnosed using the Psychopathy Checklist-Revised (PCL-R) and no schizophrenia spectrum disorders, and in matched controls (age: 35± sp="0.12"/>11). The cortex displayed up to 20% reduction in the orbitofrontal and midline structures (corrected p<0.001 bilaterally). Up to 30% tissue reduction in the basolateral nucleus, and 10-30% enlargement effects in the central and lateral nuclei indicated abnormal structure of the amygdala (corrected p=0.05 on the right; and symmetrical pattern on the left). Psychopathy features specific morphology of the main cerebral structures involved in cognitive and emotional processing, consistent with clinical and functional data, and with a hypothesis of an alternative evolutionary brain development.

Investigating the neural correlates of psychopathy: a critical review

In recent years, an increasing number of neuroimaging studies have sought to identify the brain anomalies associated with psychopathy. The results of such studies could have significant implications for the clinical and legal management of psychopaths, as well as for neurobiological models of human social behavior. In this article, we provide a critical review of structural and functional neuroimaging studies of psychopathy. In particular, we emphasize the considerable variability in results across studies, and focus our discussion on three methodological issues that could contribute to the observed heterogeneity in study data: (1) the use of between-group analyses (psychopaths vs non-psychopaths) as well as correlational analyses (normal variation in 'psychopathic' traits), (2) discrepancies in the criteria used to classify subjects as psychopaths and (3) consideration of psychopathic subtypes. The available evidence suggests that each of these issues could have a substantial effect on the reliability of imaging data. We propose several strategies for resolving these methodological issues in future studies, with the goal of fostering further progress in the identification of the neural correlates of psychopathy.

"Cool" inferior frontostriatal dysfunction in attention-deficit/hyperactivity disorder versus "hot" ventromedial orbitofrontal-limbic dysfunction in conduct disorder: a review

Attention-deficit/hyperactivity disorder (ADHD) and conduct disorder overlap behaviorally, clinically, and cognitively. An important question of potential future clinical relevance is whether these two overlapping disorders are mediated by similar or distinct underlying brain substrates. This article reviews the modern neuroimaging literature on brain structure, function, and connectivity in both disorders, shaping out commonalities and differences. Findings show that ADHD is characterized predominantly by abnormalities in inferior frontal, striatal, parietotemporal, and cerebellar regions and networks that mediate "cool"-cognitive, i.e., inhibitory, attention and timing functions associated with the disorder. Conduct disorder, by contrast, has consistently been associated with abnormalities of the "hot" paralimbic system that regulates motivation and affect, comprising lateral orbital and ventromedial prefrontal cortices, superior temporal lobes, and underlying limbic structures, most prominently the amygdala. Direct comparisons in functional imaging show that these associations of cool inferior fronto-striato-cerebellar dysfunction in ADHD and of hot orbitofrontal-paralimbic dysfunction in conduct disorder are disorder-specific. There is, hence, evidence for dissociated underlying pathophysiologies for these two disorders that may have implications for future anatomy-based differential diagnosis and prevention and intervention.

Neural basis of moral verdict and moral deliberation

How people judge something to be morally right or wrong is a fundamental question of both the sciences and the humanities. Here we aim to identify the neural processes that underlie the specific conclusion that something is morally wrong. To do this, we introduce a novel distinction between "moral deliberation," or the weighing of moral considerations, and the formation of a "moral verdict," or the commitment to one moral conclusion. We predict and identify hemodynamic activity in the bilateral anterior insula and basal ganglia that correlates with committing to the moral verdict "this is morally wrong" as opposed to "this is morally not-wrong," a finding that is consistent with research from economic decision-making. Using comparisons of deliberation-locked vs. verdict-locked analyses, we also demonstrate that hemodynamic activity in high-level cortical regions previously implicated in morality--including the ventromedial prefrontal cortex, posterior cingulate cortex, and temporoparietal junction--correlates primarily with moral deliberation as opposed to moral verdicts. These findings provide new insights into what types of processes comprise the enterprise of moral judgment, and in doing so point to a framework for resolving why some clinical patients, including psychopaths, may have intact moral judgment but impaired moral behavior.

Event-related potentials in impulsively aggressive juveniles: a retrospective chart-review study

The assessment, treatment and management of aggressive youth represent a major clinical challenge facing pediatric mental health professionals today. Although a number of studies have examined physiological differences among aggressive patients vs. controls, the current literature lacks a comprehensive examination of the electroencephalographic activity of impulsively aggressive juveniles. The current study was designed to fill this void in the literature via a retrospective chart review of 80 male and female juveniles undergoing inpatient treatment for pathologically impulsive aggression. Clinical reports for mid- and late-latency event-related potentials (ERPs) were examined to determine their correlations with aggression characteristics, as well as any differential predictive utility of hemispheric differences and auditory vs. visual potentials. Results indicated that decrements of mid-latency potentials and ERPs evoked by auditory stimuli (vs. late-latency components and visual ERPs) were more highly predictive of aggressive behavior. No significant hemispheric differences were noted. Taken together, these results have theoretical significance for the etiology of impulsive aggression, and perhaps also clinical relevance for the treatment of this condition.

Affective reactivity in heroin-dependent patients with antisocial personality disorder

The Antisocial personality disorder (ASPD), one of the most common co-morbid psychiatric disorders in heroin-dependent patients, is associated with a lack of affective modulation. The present study aimed to compare the affect-modulated startle responses of opioid-maintained heroin-dependent patients with and without ASPD relative to those of healthy controls. Sixty participants (20 heroin-dependent patients with ASPD, 20 heroin-dependent patients without ASPD, 20 healthy controls) were investigated in an affect-modulated startle experiment. Participants viewed neutral, pleasant, unpleasant, and drug-related stimuli while eye-blink responses to randomly delivered startling noises were recorded continuously. Both groups of heroin-dependent patients exhibited significantly smaller startle responses (raw values) than healthy controls. However, they showed a normal affective modulation: higher startle responses to unpleasant, lower startle responses to pleasant stimuli and no difference to drug-related stimuli compared to neutral stimuli. These findings indicate a normally modulated affective reactivity in heroin-dependent patients with ASPD.

Criminal recidivism in offenders with personality disorders and substance use disorders over 8 years of time at risk

Personality disorders (PD) and substance use disorders (SUD) lead to high violent criminality. The influence of co-morbidity on recidivism remains unclear. Recidivism of 379 offenders was assessed at 8 years of follow-up. Sixty-nine percent of PD+SUD, 45% of SUD- and 33% of PD- subjects showed any recidivism. However, violent recidivism was highest in the PD- group.

Vicarious reinforcement in rhesus macaques (macaca mulatta)

What happens to others profoundly influences our own behavior. Such other-regarding outcomes can drive observational learning, as well as motivate cooperation, charity, empathy, and even spite. Vicarious reinforcement may serve as one of the critical mechanisms mediating the influence of other-regarding outcomes on behavior and decision-making in groups. Here we show that rhesus macaques spontaneously derive vicarious reinforcement from observing rewards given to another monkey, and that this reinforcement can motivate them to subsequently deliver or withhold rewards from the other animal. We exploited Pavlovian and instrumental conditioning to associate rewards to self (M1) and/or rewards to another monkey (M2) with visual cues. M1s made more errors in the instrumental trials when cues predicted reward to M2 compared to when cues predicted reward to M1, but made even more errors when cues predicted reward to no one. In subsequent preference tests between pairs of conditioned cues, M1s preferred cues paired with reward to M2 over cues paired with reward to no one. By contrast, M1s preferred cues paired with reward to self over cues paired with reward to both monkeys simultaneously. Rates of attention to M2 strongly predicted the strength and valence of vicarious reinforcement. These patterns of behavior, which were absent in non-social control trials, are consistent with vicarious reinforcement based upon sensitivity to observed, or counterfactual, outcomes with respect to another individual. Vicarious reward may play a critical role in shaping cooperation and competition, as well as motivating observational learning and group coordination in rhesus macaques, much as it does in humans. We propose that vicarious reinforcement signals mediate these behaviors via homologous neural circuits involved in reinforcement learning and decision-making.

'Promising' therapies: neuroscience, clinical practice, and the treatment of psychopathy

Neuroscientific research into mental health commands generous funding, suggesting neuroscience is understood by a variety of actors and institutions as having significant potential to enhance the therapeutic practices of psychiatrists. This article interrogates this 'therapeutic promise' of neuroscience through the case study of the psychiatric condition personality disorder. Specifically, the focus is on the promissory discourse of clinicians specialising in the management of two variants of personality disorder--antisocial personality disorder and psychopathy--and researchers investigating the neurobiology of these constructs. The article discusses the respondents' ambivalent expectations regarding the therapeutic promise of brain research, and shows how these are structured by understandings of the ontology of personality disorder. In turn, these ambivalences direct our attention to practical issues surrounding the potential of neuroscience to translate into and enhance clinical practice, as well as theoretical concerns revolving around the place and role of the biological within contemporary neuroscience, psychiatry and psychology. In sum, the necessity of large material and symbolic investments in neuroscience should, perhaps, be reflected upon more critically, and analytic encounters with this discipline must keep in mind it's at times surprising commitment to the realms of the social and the psychological.

Disrupted reinforcement signaling in the orbitofrontal cortex and caudate in youths with conduct disorder or oppositional defiant disorder and a high level of psychopathic traits

OBJECTIVE

Dysfunction in the amygdala and orbitofrontal cortex has been reported in youths and adults with psychopathic traits. The specific nature of the functional irregularities within these structures remains poorly understood. The authors used a passive avoidance task to examine the responsiveness of these systems to early stimulus-reinforcement exposure, when prediction errors are greatest and learning maximized, and to reward in youths with psychopathic traits and comparison youths.

METHOD

While performing the passive avoidance learning task, 15 youths with conduct disorder or oppositional defiant disorder plus a high level of psychopathic traits and 15 healthy subjects completed a 3.0-T fMRI scan.

RESULTS

Relative to the comparison youths, the youths with a disruptive behavior disorder plus psychopathic traits showed less orbitofrontal responsiveness both to early stimulus-reinforcement exposure and to rewards, as well as less caudate response to early stimulus-reinforcement exposure. There were no group differences in amygdala responsiveness to these two task measures, but amygdala responsiveness throughout the task was lower in the youths with psychopathic traits.

CONCLUSIONS

Compromised sensitivity to early reinforcement information in the orbitofrontal cortex and caudate and to reward outcome information in the orbitofrontal cortex of youths with conduct disorder or oppositional defiant disorder plus psychopathic traits suggests that the integrated functioning of the amygdala, caudate, and orbitofrontal cortex may be disrupted. This provides a functional neural basis for why such youths are more likely to repeat disadvantageous decisions. New treatment possibilities are raised, as pharmacologic modulations of serotonin and dopamine can affect this form of learning.

Aberrant neural processing of moral violations in criminal psychopaths

A defining characteristic of psychopathy is the willingness to intentionally commit moral transgressions against others without guilt or remorse. Despite this "moral insensitivity," the behavioral and neural correlates of moral decision-making in psychopathy have not been well studied. To address this issue, the authors used functional magnetic resonance imaging (fMRI) to record hemodynamic activity in 72 incarcerated male adults, stratified into psychopathic (n = 16) and nonpsychopathic (n = 16) groups based on scores from the Hare Psychopathy Checklist-Revised (R. D. Hare, 2003), while they made decisions regarding the severity of moral violations of pictures that did or did not depict moral situations. Consistent with hypotheses, an analysis of brain activity during the evaluation of pictures depicting moral violations in psychopaths versus nonpsychopaths showed atypical activity in several regions involved in moral decision-making. This included reduced moral/nonmoral picture distinctions in the ventromedial prefrontal cortex and anterior temporal cortex in psychopaths relative to nonpsychopaths. In a separate analysis, the association between severity of moral violation ratings and brain activity across participants was compared in psychopaths versus nonpsychopaths. Results revealed a positive association between amygdala activity and severity ratings that was greater in nonpsychopaths than psychopaths, and a negative association between posterior temporal activity and severity ratings that was greater in psychopaths than nonpsychopaths. These results reveal potential neural underpinnings of moral insensitivity in psychopathy and are discussed with reference to neurobiological models of morality and psychopathy.

Author response - Reactive aggression and functional, not neural, specificity

This article is an author response to Harenski and Kiehl's (2010) commentary on Blair (2010).

Neurodevelopmental marker for limbic maldevelopment in antisocial personality disorder and psychopathy

BACKGROUND

Antisocial personality disorder and psychopathy have been hypothesised to have a neurodevelopmental basis, but this proposition has not been formally tested.

AIMS

This study tests the hypothesis that individuals with cavum septum pellucidum (CSP), a marker of limbic neural maldevelopment, will show higher levels of psychopathy and antisocial personality.

METHOD

Cavum septum pellucidum was assessed using anatomical magnetic resonance imaging in a community sample. Those with CSP (n = 19) were compared with those lacking CSP (n = 68) on antisocial personality, psychopathy and criminal offending.

RESULTS

Those with CSP had significantly higher levels of antisocial personality, psychopathy, arrests and convictions compared with controls. The pervasiveness of this association was indicated by the fact that those lacking a diagnosis of antisocial personality disorder, but who were charged or convicted for an offence, had a more extensive CSP than non-antisocial controls. Results could not be attributed to prior trauma exposure, head injury, demographic factors or comorbid psychiatric conditions.

CONCLUSIONS

Our findings appear to be the first to provide evidence for a neurodevelopmental brain abnormality in those with antisocial personality disorder and psychopathy, and support the hypothesis that early maldevelopment of limbic and septal structures predisposes to the spectrum of antisocial behaviours.

Neural abnormalities in early-onset and adolescence-onset conduct disorder

CONTEXT

Conduct disorder (CD) is characterized by severe antisocial behavior that emerges in childhood (early-onset CD [EO-CD]) or adolescence (adolescence-onset CD [AO-CD]). Early-onset CD is proposed to have a neurodevelopmental basis, whereas AO-CD is thought to emerge owing to social mimicry of deviant peers. However, this developmental taxonomic theory is debated after reports of neuropsychological impairments in both CD subtypes. A critical, although unaddressed, issue is whether these subtypes present similar or distinct neurophysiological profiles. Hence, we investigated neurophysiological responses to emotional and neutral faces in regions associated with antisocial behavior (ie, the amygdala, ventromedial prefrontal cortex, insula, and orbitofrontal cortex) in individuals with EO-CD and AO-CD and in healthy control subjects.

OBJECTIVE

To investigate whether EO-CD and AO-CD subjects show neurophysiological abnormalities.

DESIGN

Case-control study.

SETTING

Government research institute, university department.

PARTICIPANTS

Seventy-five male adolescents and young adults aged 16 to 21 years, including 27 with EO-CD, 25 with AO-CD, and 23 healthy controls. Main Outcome Measure Neural activations measured by functional magnetic resonance imaging while participants viewed angry, sad, and neutral faces.

RESULTS

Comparing angry vs neutral faces, participants with both CD subtypes displayed reduced responses in regions associated with antisocial behavior compared with controls; differences between the CD subtypes were not significant. Comparing each expression with fixation baseline revealed an abnormal (increased) amygdala response to neutral but not angry faces in both groups of CD relative to controls. For sad vs neutral faces, reduced amygdala activation was observed in EO-CD relative to AO-CD and control participants. Comparing each expression with fixation revealed hypoactive amygdala responses to sadness in individuals with EO-CD relative to AO-CD participants and controls. These findings were not accounted for by attention-deficit/hyperactivity disorder symptoms.

CONCLUSIONS

Neurophysiological abnormalities are observed in both CD subtypes, contrary to the developmental taxonomic theory of CD. Additional amygdala hypofunction in relation to sad expressions might indicate why EO-CD is more severe and persistent than AO-CD.

The 'antisocial' person: an insight in to biology, classification and current evidence on treatment

BACKGROUND

This review analyses and summarises the recent advances in understanding the neurobiology of violence and empathy, taxonomical issues on defining personality disorders characterised by disregard for social norms, evidence for efficacy of different treatment modalities and ethical implications in defining 'at-risk' individuals for preventive interventions.

METHODS

PubMed was searched with the keywords 'antisocial personality disorder', 'dissocial personality disorder' and 'psychopathy'. The search was limited to articles published in English over the last 10 years (1999 to 2009)

RESULTS

Both diagnostic manuals used in modern psychiatry, the Diagnostic and Statistical Manual published by the American Psychiatric Association and the International Classification of Diseases published by the World Health Organization, identify a personality disorder sharing similar traits. It is termed antisocial personality disorder in the diagnostic and statistical manual and dissocial personality disorder in the International Classification of Diseases. However, some authors query the ability of the existing manuals to identify a special category termed 'psychopathy', which in their opinion deserves special attention. On treatment-related issues, many psychological and behavioural therapies have shown success rates ranging from 25% to 62% in different cohorts. Multisystemic therapy and cognitive behaviour therapy have been proven efficacious in many trials. There is no substantial evidence for the efficacy of pharmacological therapy. Currently, the emphasis is on early identification and prevention of antisocial behaviour despite the ethical implications of defining at-risk children.

CONCLUSIONS

Further research is needed in the areas of neuroendocrinological associations of violent behaviour, taxonomic existence of psychopathy and efficacy of treatment modalities.

What imaging tells us about violence in anti-social men

This paper provides an overview of imaging studies in samples of men with personality disorder (PD) who have been violent. Mention is also made of the work of two groups that have looked at the neural correlates of violence across diagnostic categories, including schizophrenia and anti-social PD given their relevance in the field. The paper focuses on the notion that aggressive behaviour can be conceptualised in terms of at least two types, reactive and pro-active, and that few studies separate them. The neuro-anatomical basis of aggression and associated neurobehavioural theories are discussed in relation to clinical disorders (mainly anti-social personality pathology) associated with these different types of aggressive behaviour. Structural (computed tomography, magnetic resonance imaging) and functional (positron emission tomography, fMRI, single-photon emission tomography) studies with violent people variously characterised as anti-social or having psychopathy will be critically reviewed.

Early environmental predictors of the affective and interpersonal constructs of psychopathy

Early childhood maltreatment (i.e., physical, sexual, emotional abuse) and caregiver disruptions are hypothesized to be instrumental in altering the neurobiology of the brain, particularly the amygdala, and contributing to the development of the affective deficits examined in individuals with psychopathy. Exposure to early untoward life events in models of rodent and nonhuman primates changes the neurobiology of the stress response. It is hypothesized that these changes may permanently shape brain regions that mediate stress and emotion and therefore play a role in the etiology of affective disorders in humans. The significance of experience (e.g., the intensity/severity, chronicity/duration, and developmental timing of experiences) and how the accompanying changes in the activity of the hypothalamic-pituitary-adrenocortical system affect alterations in the amygdala are discussed as critical contributors to the etiology of psychopathy. A model is proposed in which early maltreatment experiences contribute to alterations to the amygdala and produce a blunted or dissociative response to stress, a key factor in the affective deficits observed in psychopaths.

Neuroimaging of psychopathy and antisocial behavior: a targeted review

The goal of this article is to provide a selective and targeted review of the neuroimaging literature on psychopathic tendencies and antisocial behavior and to explore the extent to which this literature supports recent cognitive neuroscientific models of psychopathy and antisocial behavior. The literature reveals that individuals who present with an increased risk for reactive, but not instrumental, aggression show increased amygdala responses to emotionally evocative stimuli. This is consistent with suggestions that such individuals are primed to respond strongly to an inappropriate extent to threatening or frustrating events. In contrast, individuals with psychopathic tendencies show decreased amygdala and orbitofrontal cortex responses to emotionally provocative stimuli or during emotional learning paradigms. This is consistent with suggestions that such individuals face difficulties with basic forms of emotional learning and decision making.

Psychopaths know right from wrong but don't care

Adult psychopaths have deficits in emotional processing and inhibitory control, engage in morally inappropriate behavior, and generally fail to distinguish moral from conventional violations. These observations, together with a dominant tradition in the discipline which sees emotional processes as causally necessary for moral judgment, have led to the conclusion that psychopaths lack an understanding of moral rights and wrongs. We test an alternative explanation: psychopaths have normal understanding of right and wrong, but abnormal regulation of morally appropriate behavior. We presented psychopaths with moral dilemmas, contrasting their judgments with age- and sex-matched (i) healthy subjects and (ii) non-psychopathic, delinquents. Subjects in each group judged cases of personal harms (i.e. requiring physical contact) as less permissible than impersonal harms, even though both types of harms led to utilitarian gains. Importantly, however, psychopaths' pattern of judgments on different dilemmas was the same as those of the other subjects. These results force a rejection of the strong hypothesis that emotional processes are causally necessary for judgments of moral dilemmas, suggesting instead that psychopaths understand the distinction between right and wrong, but do not care about such knowledge, or the consequences that ensue from their morally inappropriate behavior.

Attention moderates the fearlessness of psychopathic offenders

BACKGROUND

Psychopathic behavior is generally attributed to a fundamental, amygdala-mediated deficit in fearlessness that undermines social conformity. An alternative view is that psychopathy involves an attention-related deficit that undermines the processing of peripheral information, including fear stimuli.

METHODS

We evaluated these alternative hypotheses by measuring fear-potentiated startle (FPS) in a group of 125 prisoners under experimental conditions that 1) focused attention directly on fear-relevant information or 2) established an alternative attentional focus. Psychopathy was assessed using Hare's Psychopathy Checklist-Revised (PCL-R).

RESULTS

Psychopathic individuals displayed normal FPS under threat-focused conditions but manifested a significant deficit in FPS under alternative-focus conditions. Moreover, these findings were essentially unchanged when analyses employed the interpersonal/affective factor of the PCL-R instead of PCL-R total scores.

CONCLUSIONS

The results provide unprecedented evidence that higher-order cognitive processes moderate the fear deficits of psychopathic individuals. These findings suggest that psychopaths' diminished reactivity to fear stimuli, and emotion-related cues more generally, reflect idiosyncrasies in attention that limit their processing of peripheral information. Although psychopathic individuals are commonly described as cold-blooded predators who are unmotivated to change, the attentional dysfunction identified in this study supports an alternative interpretation of their chronic disinhibition and insensitive interpersonal style.

Psychopathy: assessment and forensic implications

Psychopathy is commonly viewed as a personality disorder defined by a cluster of interpersonal, affective, lifestyle, and antisocial traits and behaviours, including grandiosity, egocentricity, deceptiveness, shallow emotions, lack of empathy or remorse, irresponsibility, impulsivity, and a tendency to violate social norms. In our article, we outline standard methods for the assessment of psychopathy, its association with antisocial personality disorder (ASPD), and its implications for clinical and forensic issues, including crime and violence, risk assessment, and treatment options.

Prefrontal structural and functional brain imaging findings in antisocial, violent, and psychopathic individuals: a meta-analysis

Brain-imaging studies suggest that antisocial and violent behavior is associated with structural and functional deficits in the prefrontal cortex, but there is heterogeneity in findings and it is unclear whether findings apply to psychopaths, non-violent offenders, community-based samples, and studies employing psychiatric controls. A meta-analysis was conducted on 43 structural and functional imaging studies, and the results show significantly reduced prefrontal structure and function in antisocial individuals. Effect sizes were significant for both structural and functional studies. With minor exceptions, no statistically significant moderating effects of sample characteristics and methodological variables were observed. Findings were localized to the right orbitofrontal cortex, right anterior cingulate cortex, and left dorsolateral prefrontal cortex. Findings confirm the replicability of prefrontal structural and functional impairments in antisocial populations and highlight the involvement of orbitofrontal, dorsolateral frontal, and anterior cingulate cortex in antisocial behavior.

Development and etiology of disruptive and delinquent behavior

This review examines the development and etiology of disruptive behavior [symptoms of oppositional defiant disorder (ODD), conduct disorder (CD), and psychopathic features] and delinquency (particularly violence). We address selected key developmental issues, including (a) to what extent negative emotional ODD symptoms are associated with later internalizing disorders, (b) whether psychopathic features provide added predictive utility beyond traditional disruptive behaviors, and (c) the role of oppositional behavior and conduct problems in the development of violence. This review also focuses on the causes of ODD, CD, psychopathic features, and delinquency and explores the extent to which the causes of disruptive and delinquent behavior are the same. We examine the degree to which risk and promotive factors change with age and whether promotive factors buffer the impact of risk factors. Finally, we explore the question of whether there are developmental shifts in children's exposure to risk and promotive factors.

Reactive aggression in psychopathy and the role of frustration: susceptibility, experience, and control

This article is a commentary on 'Psychopathy, frustration, and reactive aggression: The role of ventromedial prefrontal cortex' (Blair, 2010).

Localization of deformations within the amygdala in individuals with psychopathy

CONTEXT

Despite the repeated findings of impaired fear conditioning and affective recognition in psychopathic individuals, there has been a paucity of brain imaging research on the amygdala and no evidence suggesting which regions within the amygdala may be structurally compromised in individuals with psychopathy.

OBJECTIVE

To detect global and regional anatomical abnormalities in the amygdala in individuals with psychopathy.

DESIGN

Cross-sectional design using structural magnetic resonance imaging.

SETTING

Participants were recruited from high-risk communities (temporary employment agencies) in the Los Angeles, California, area and underwent imaging at a hospital research facility at the University of Southern California.

PARTICIPANTS

Twenty-seven psychopathic individuals as defined by the Hare Psychopathy Checklist-Revised and 32 normal controls matched on age, sex, and ethnicity.

MAIN OUTCOME MEASURES

Amygdala volumes were examined using traditional volumetric analyses and surface-based mesh modeling methods were used to localize regional surface deformations.

RESULTS

Individuals with psychopathy showed significant bilateral volume reductions in the amygdala compared with controls (left, 17.1%; right, 18.9%). Surface deformations were localized in regions in the approximate vicinity of the basolateral, lateral, cortical, and central nuclei of the amygdala. Significant correlations were found between reduced amygdala volumes and increased total and facet psychopathy scores, with correlations strongest for the affective and interpersonal facets of psychopathy.

CONCLUSIONS

Results provide the first evidence, to our knowledge, of focal amygdala abnormalities in psychopathic individuals and corroborate findings from previous lesion studies. Findings support prior hypotheses of amygdala deficits in individuals with psychopathy and indicate that amygdala abnormalities contribute to emotional and behavioral symptoms of psychopathy.

Reduced brain activation in euthymic bipolar patients during response inhibition: an event-related fMRI study

Deficits in inhibitory control have been reported in euthymic bipolar disorder patients. To date, data on the neuroanatomical correlates of these deficits are exclusively related to cognitive inhibition. This study aimed to examine the neural substrates of motor inhibitory control in euthymic bipolar patients. Groups of 20 patients with euthymic bipolar disorder and 20 demographically matched healthy subjects underwent event-related functional magnetic resonance imaging while performing a Go-NoGo task. Between-group differences in brain activation associated with motor response inhibition were assessed by using random-effects analyses. Although euthymic bipolar patients and healthy subjects performed similarly on the Go-NoGo task, they showed different patterns of brain activation associated with response inhibition. Specifically, patients exhibited significantly decreased activation in the left frontopolar cortex and bilateral dorsal amygdala compared with healthy subjects. There were no brain regions that were significantly more activated in patients than in healthy subjects. The findings suggest that euthymic bipolar patients have deficits in their ability to engage the left frontopolar cortex and bilateral dorsal amygdala during response inhibition. Further research should ascertain the role that such deficits may play in the emergence of impulsive behaviors that characterize bipolar disorder.

Aggression, psychopathy and brain imaging - Review and future recommendations

Violent behavior appears to result from a complex web of interacting genetic as well as environmental factors. Psychopathy is a strong predictor for relapse in violent acts. The current review shed light on rapidly expanding knowledge in brain imaging related to violent behavior and psychopathy. A literature search was performed in PubMed, Cochrane and PsycInfo combining the key words: mentally disordered offender/aggression/violence/ crime/forensic psychiatry/brain imaging neuroimaging/fMRI/MRI/PET/SPECT/lack of empathy/psychopathy and antisocial personality disorder. The reviewed material, which consisted of 48 articles, indicates a rather strong consensus on the connection between dysfunctional parts of the frontal and temporal lobes and violent antisocial behavior and psychopathy. In future studies, it would be useful to focus on the limbic system and to investigate which parts of the frontal lobes and cerebral networks that are of interest in the psychopathic personality. Moreover, the reviewed material highlights some of the methodological difficulties in this area of research such as selection bias in the recruitment of patients, inadequate matching of control subjects, and sometimes incongruous results. In the future we hope that brain imaging can be used to map biological deviations in different offenders in order to try to learn more about the different mechanisms behind violent behaviors.

Neural and behavioural responses to threat in men with a history of serious violence and schizophrenia or antisocial personality disorder

BACKGROUND

Contemporary theories and evidence implicate defective emotion regulation in violent behaviour. The two psychiatric illnesses most implicated in violence are schizophrenia and antisocial personality disorder (APD). This study examined behavioural and brain abnormalities in violent men with schizophrenia or APD during anticipatory fear.

METHOD

Fifty-three men [14 non-violent healthy controls, 13 with schizophrenia and a history of serious violence (VSZ), 13 with schizophrenia without a history of violence (SZ), 13 with APD and a history of serious violence] underwent blood-oxygenation-level-dependent fMRI during an experiment involving repeated presentations of 'safe' and 'threat of electric shock' conditions and provided ratings of shock anticipation and fear. Schizophrenia patients did not have co-morbid APD.

RESULTS

VSZ participants reported the highest, and APD participants the lowest, level of shock anticipation and fear, with intermediate ratings by SZ and healthy participants. The violent, relative to non-violent, groups showed altered activity modulation in occipital and temporal regions, from early to latter parts of threat periods. Additionally, VSZ patients displayed exaggerated whereas APD patients showed attenuated thalamic-striatal activity during latter threat periods.

CONCLUSIONS

Aberrant activity in occipital and temporal regions when exposed to sustained visual threat cues is associated with a predisposition to violence in both schizophrenia and APD. This common biological deficit, however, appears to arise from dissimilar behavioural mechanisms related to differences in the strength of aversive conditioning and behavioural response to sustained threat cues (enhanced in VSZ; attenuated in APD), also reflected in opposite patterns of alternations in thalamic-striatal activity, in these two disorders.

Neuroticism and psychopathy predict brain activation during moral and nonmoral emotion regulation

Functional neuroimaging has identified brain regions associated with voluntary regulation of emotion, including the prefrontal cortex and amygdala. The neural mechanisms underlying individual differences in emotion regulation have not been extensively studied. We investigated the neural correlates of neuroticism and psychopathic personality traits in the context of an emotion regulation task. Results showed that amygdala activity elicited by unpleasant pictures was positively correlated with neuroticism and negatively correlated with a specific psychopathic trait related to emotional underreactivity. During active attempts to decrease emotional responses to unpleasant pictures, superior and ventrolateral prefrontal activity was positively correlated with psychopathy, but not with neuroticism. In contrast, dorsolateral prefrontal activity was positively correlated with neuroticism, but not with psychopathy. Psychopathy was also negatively correlated with medial prefrontal activity in response to pictures depicting moral violations, suggesting reduced emotional responses to moral stimuli in individuals with high levels of psychopathic traits. These results demonstrate dissociable influences of different personality traits on neural activity associated with responses to emotional stimuli and on the recruitment of regulation-related brain activity during the active down-regulation of responses to negative emotional stimuli. These results have implications for the etiology of trait-based psychopathology involving emotional dysregulation.

Psychopathy, attention and emotion

Psychopathy is a developmental disorder marked by emotional hypo-responsiveness and an increased risk for antisocial behavior. Influential attention-based accounts of psychopathy have long been made; however, these accounts have made relatively little reference to general models of attention in healthy individuals. This review has three aims: (1) to summarize current cognitive neuroscience data on differing attentional systems; (2) to examine the functional integrity of these attentional systems in individuals with psychopathy; and (3) to consider the implications of these data for attention and emotion dysfunction accounts of psychopathy.