Brain abnormalities in antisocial individuals: implications for the law

Understanding the Role of Oxidative Stress, Neuroinflammation and Abnormal Myelination in Excessive Aggression Associated with Depression: Recent Input from Mechanistic Studies

Aggression and deficient cognitive control problems are widespread in psychiatric disorders, including major depressive disorder (MDD). These abnormalities are known to contribute significantly to the accompanying functional impairment and the global burden of disease. Progress in the development of targeted treatments of excessive aggression and accompanying symptoms has been limited, and there exists a major unmet need to develop more efficacious treatments for depressed patients. Due to the complex nature and the clinical heterogeneity of MDD and the lack of precise knowledge regarding its pathophysiology, effective management is challenging. Nonetheless, the aetiology and pathophysiology of MDD has been the subject of extensive research and there is a vast body of the latest literature that points to new mechanisms for this disorder. Here, we overview the key mechanisms, which include neuroinflammation, oxidative stress, insulin receptor signalling and abnormal myelination. We discuss the hypotheses that have been proposed to unify these processes, as many of these pathways are integrated for the neurobiology of MDD. We also describe the current translational approaches in modelling depression, including the recent advances in stress models of MDD, and emerging novel therapies, including novel approaches to management of excessive aggression, such as anti-diabetic drugs, antioxidant treatment and herbal compositions.

Altered Resting-State Functional Connectivity in the Default Mode Network in Male Juvenile Violent Offenders

Young males are often associated with more violence, leading to some serious negative consequences. However, the physiology and the neuroimaging patterns underlying juvenile violence remain unclear. Of the limited knowledge on juvenile violence, the default mode network has been known to be associated with its pathophysiology. This study aimed to investigate functional connectivity alterations of the default mode network in male juvenile violent offenders. 31 juvenile violent offenders in a high-security facility, who were convicted of aggressive behaviors by court, and 28 normal controls from a middle school were recruited as participants. They underwent a resting-state functional magnetic resonance imaging scan. And independent component analysis approaches were used to analyze their data. Compared to the normal controls, the juvenile violent offenders showed a different default mode network pattern, with the functional connectivity increased in the posterior cingulate, and decreased in the right middle temporal, left angular, right precuneus and right middle frontal cortex. Our findings revealed that the male juvenile violent offenders were associated with abnormal default mode network functional connectivity, which might be a neuroimaging basis for their tendency to violence.

Is the Psychopathic Brain an Artifact of Coding Bias? A Systematic Review

Questionable research practices are a well-recognized problem in psychology. Coding bias, or the tendency of review studies to disproportionately cite positive findings from original research, has received comparatively little attention. Coding bias is more likely to occur when original research, such as neuroimaging, includes large numbers of effects, and is most concerning in applied contexts. We evaluated coding bias in reviews of structural magnetic resonance imaging (sMRI) studies of PCL-R psychopathy. We used PRISMA guidelines to locate all relevant original sMRI studies and reviews. The proportion of null-findings cited in reviews was significantly lower than those reported in original research, indicating coding bias. Coding bias was not affected by publication date or review design. Reviews recommending forensic applications—such as treatment amenability or reduced criminal responsibility—were no more accurate than purely theoretical reviews. Coding bias may have contributed to a perception that structural brain abnormalities in psychopaths are more consistent than they actually are, and by extension that sMRI findings are suitable for forensic application. We discuss possible sources for the pervasive coding bias we observed, and we provide recommendations to counteract this bias in review studies. Until coding bias is addressed, we argue that this literature should not inform conclusions about psychopaths' neurobiology, especially in forensic contexts.

Structural Brain Correlates of the Externalizing Spectrum in Young Adults

The externalizing spectrum, including traits and behaviors such as aggression, reduced inhibitiory control and substance abuse, is associated with altered prefrontal brain morphology. However, the degree to which different manifestations of the externalizing spectrum are associated with distinct or overlapping variations in individual brain morphology is unclear. Here, we therefore used structural magnetic resonance imaging, self-report assessment, and a response inhibition task in a sample of 59 young adults to examine how cortical thickness in the anterior cingulate cortex (ACC), orbitofrontal cortex (OFC), and dorsolateral prefrontal cortex (DLPFC) relate to four different manifestations of the externalizing spectrum: disinhibition, callous aggression, substance abuse, and behavioral inhibitory control. Using Bayesian linear regression models controlling for age, gender, and years of education, we found that the different manifestations of the externalizing spectrum were associated with both distinct and overlapping morphology variations. Specifically, both callous aggression and inhibitory control was associated with increased cortical thickness of the OFC, a region involved in reward processing, decision-making, and regulation of anxiety and fear. Both disinhibition and substance abuse were associated with DLPFC thickness, although with opposite association patterns, possibly reflecting processes related to inhibitory control, working memory and attention. Moreover, disinhibition, but not callous aggression or substance abuse, was associated with behavioral inhibitory control. Our results provide further support for the link between externalizing behaviors and prefrontal brain morphology, while identifying distinct prefrontal areas associated with different clinically relevant manifestations. These findings may help guide further research aimed at developing novel treatment and intervention strategies for externalizing behaviors and disorders.

The neurobiology of human aggressive behavior: Neuroimaging, genetic, and neurochemical aspects

In modern societies, there is a strive to improve the quality of life related to risk of crimes which inevitably requires a better understanding of brain determinants and mediators of aggression. Neurobiology provides powerful tools to achieve this end. Pre-clinical and clinical studies show that changes in regional volumes, metabolism-function and connectivity within specific neural networks are related to aggression. Subregions of prefrontal cortex, insula, amygdala, basal ganglia and hippocampus play a major role within these circuits and have been consistently implicated in biology of aggression. Genetic variations in proteins regulating the synthesis, degradation, and transport of serotonin and dopamine as well as their signal transduction have been found to mediate behavioral variability observed in aggression. Gene-gene and gene-environment interactions represent additional important risk factors for aggressiveness. Considering the social burden of pathological forms of aggression, more basic and translational studies should be conducted to accelerate applications to clinical practice, justice courts, and policy making.

Executive functioning among first time and recidivist inmates in Uruguay

Previous research has found association between antisocial behavior and deficits in executive functioning. However, research into a link between them accounting for criminal history has found divergent results in western countries. The present study sought to determine the severity of executive functioning deficits in offenders compared to a normative sample, and the differences between first time offenders as compared to recidivists in Uruguay using a cross-sectional design. The neuropsychological performance of 334 male adult inmates was assessed using the BRIEF- A and a normative sample of 377. Results indicated that offenders performed significantly worse than non-offenders in the global score and the subscales of the BRIEF-A. Moreover, first time offenders exhibited less performance deficits in cognitive functioning than recidivist offenders. Compared to first time offenders, recidivist showed executive dysfunction concerning behavioral regulation index and globally. These results enhance our knowledge about executive dysfunction associated with criminality and may help to tailor the offenders' programs to offenders with executive deficits.

There are More than Two Sides to Antisocial Behavior: The Inextricable Link between Hemispheric Specialization and Environment

Human functions and traits are linked to cerebral networks serving different emotional and cognitive control systems, some of which rely on hemispheric specialization and integration to promote adaptive goal-directed behavior. Among the neural systems discussed in this context are those underlying pro- and antisocial behaviors. The diverse functions and traits governing our social behavior have been associated with lateralized neural activity. However, as with other complex behaviors, specific hemispheric roles are difficult to elucidate. This is due largely to environmental and contextual influences, which interact with neural substrates in the development and expression of pro and antisocial functions. This paper will discuss the reciprocal ties between environmental factors and hemispheric functioning in the context of social behavior. Rather than an exhaustive review, the paper will attempt to familiarize readers with the prominent literature and primary questions to encourage further research and in-depth discussion in this field.

Neuroanatomical Differences Among Sexual Offenders: A Targeted Review with Limitations and Implications for Future Directions

As sexual assault and child sexual abuse continue to be worldwide public health concerns, research has continued to explore factors associated with sexual offending. Structural and functional neuroanatomical brain differences have been examined in an effort to differentiate sexual offenders and their behavior. This targeted review searched PubMed and Google Scholar for empirical studies using brain imaging techniques to examine possible structural or functional differences among control groups compared with at least one group of sexual offenders with contact offenses. This targeted review summarizes the structural and functional findings of 15 brain imaging studies (i.e., computed tomography, diffusion tensor imaging, magnetic resonance imaging, positron emission tomography, and functional magnetic resonance imaging), which suggest possible differences in brain size and gray matter volume, cortical thickness, white matter connectivity, and specific structural and functional differences among brain regions (fronto-temporal region, amygdala, prefrontal cortex, etc.). The methodological limitations of brain imaging studies and the associated findings with regard to sexual offenders are highlighted, as research indicates that many of the proposed differences in brain structure and function are not unique to this population. We further highlight several limitations to using neuroimaging studies to examine this population of interest, including publication bias, small sample size, underpowered studies, and all-male samples. As these results are mixed and findings are not seemingly unique to sexual offenders, we suggest future sexual offender research may benefit from focusing on more financially feasible options, such as neuropsychological assessment approaches, to assess for and attend to offenders' criminogenic and rehabilitative/therapeutic needs in alignment with the risk-need-responsivity model.

Biocognitive Classification of Antisocial Individuals Without Explanatory Reductionism

Effective and specifically targeted social and therapeutic responses for antisocial personality disorders and psychopathy are scarce. Some authors maintain that this scarcity should be overcome by revising current syndrome-based classifications of these conditions and devising better biocognitive classifications of antisocial individuals. The inspiration for the latter classifications has been embedded in the Research Domain Criteria (RDoC) approach. RDoC-type approaches to psychiatric research aim at transforming diagnosis, provide valid measures of disorders, aid clinical practice, and improve health outcomes by integrating the data on the genetic, neural, cognitive, and affective systems underlying psychiatric conditions. In the first part of the article, we discuss the benefits of such approaches compared with the dominant syndrome-based approaches and review recent attempts at building biocognitive classifications of antisocial individuals. Other researchers, however, have objected that biocognitive approaches in psychiatry are committed to an untenable form of explanatory reductionism. Explanatory reductionism is the view that psychological disorders can be exclusively categorized and explained in terms of their biological causes. In the second part of the article, we argue that RDoC-like approaches need not be associated with explanatory reductionism. Moreover, we argue how this is the case for a specific biocognitive approach to classifying antisocial individuals.

Iron Oxide Nanoparticles Affects Behaviour and Monoamine Levels in Mice

Iron oxide (Fe₂O₃) nanoparticles (NPs) attract the attention of clinicians for its unique magnetic and paramagnetic properties, which are exclusively used in neurodiagnostics and therapeutics among the other biomedical applications. Despite numerous research findings has already proved neurotoxicity of Fe₂O₃-NPs, factors affecting neurobehaviour has not been elucidated. In this study, mice were exposed to Fe₂O₃-NPs (25 and 50 mg/kg body weight) by oral intubation daily for 30 days. It was observed that Fe₂O₃-NPs remarkably impair motor coordination and memory. In the treated brain regions, mitochondrial damage, depleted energy level and decreased ATPase (Mg²⁺, Ca²⁺ and Na⁺/K⁺) activities were observed. Disturbed ion homeostasis and axonal demyelination in the treated brain regions contributes to poor motor coordination. Increased intracellular calcium ([Ca²⁺]_i) and decreased expression of growth associated protein 43 (GAP43) impairs vesicular exocytosis could result in insufficient signal between neurons. In addition, levels of dopamine (DA), norepinephrine (NE) and epinephrine (EP) were found to be altered in the subjected brain regions in correspondence to the expression of monoamine oxidases (MAO). Along with all these factors, over expression of glial fibrillary acidic protein (GFAP) confirms the neuronal damage, suggesting the evidences for behavioural changes.

Higher Trait Psychopathy Is Associated with Increased Risky Decision-Making and Less Coincident Insula and Striatal Activity

Higher trait levels of psychopathy have been associated with both a tendency to maintain disadvantageous decision-making strategies and aberrant cortico-limbic neural activity. To explore the neural mechanisms associated with the psychopathy-related propensity to continue selecting risky choices, a non-forensic sample of participants completed a self-report psychopathy questionnaire and two runs of a risky decision-making task during H₂¹⁵O positron emission tomography (PET) scanning. In this secondary data analysis study, we leveraged data previously collected to examine the impact of previous drug use on risky decision-making to explore the relations between self-reported psychopathy and behavioral and brain metrics during performance of the Cambridge Decision-Making Task (CDMT), in which volunteers chose between small/likely or large/unlikely potential reward outcomes. Behaviorally, we observed that psychopathy scores were differentially correlated with the percent of risky decisions made in run 1 vs. run 2 of the task. Specifically, higher levels of psychopathy, above and beyond that attributable to drug use or sex, were associated with greater tendencies to make risky selections only in the second half (run 2) of the task. In parallel, psychopathy scores negatively correlated with regional cerebral blood flow (rCBF) in the right insula and right ventral striatum during run 2 of the CDMT. These exploratory outcomes suggest that greater levels of psychopathy may be associated with an inability to translate experience with negative outcomes into behavioral adaptations possibly due to decreased neural efficiency in regions related to somatic and/or reward feedback processes.

Structural brain correlates of interpersonal violence: Systematic review and voxel-based meta-analysis of neuroimaging studies

Owing to inconsistent nomenclature and results, we have undertaken a label-based review and anatomical likelihood estimation (ALE) meta-analysis of studies measuring the quantitative association between regional grey matter (GM) volume and interpersonal violence. Following PRISMA guidelines, we identified studies by searching 3 online databases (Embase, Medline, PsycInfo) and reference lists. Thirty-five studies were included in the label-based review, providing information for 1288 participants and 86 brain regions. Per region, 0-57% of the results indicated significant reductions in GM volume, while 0-23% indicated significant increases. The only region for which more than half of all results indicated significant reductions was the parietal lobe. However, these results were dispersed across subregions. The ALE meta-analysis, which included 6 whole-brain voxel-based morphometry studies totaling 278 participants and reporting 144 foci, showed no significant clusters of reduced GM volume. No material differences were observed when excluding experiments using reactive violence as outcome or subjects diagnosed with psychopathy. Possible explanations for these findings are phenomenological and etiological heterogeneity, and insufficient power in the label-based review and ALE meta-analysis to detect small effects. We recommend that future studies distinguish between subtypes of interpersonal violence, and investigate mediation by underlying emotional and cognitive processes.

Association of monoamine oxidase-A genetic variants and amygdala morphology in violent offenders with antisocial personality disorder and high psychopathic traits

Violent offending is elevated among individuals with antisocial personality disorder (ASPD) and high psychopathic traits (PP). Morphological abnormalities of the amygdala and orbitofrontal cortex (OFC) are present in violent offenders, which may relate to the violence enacted by ASPD + PP. Among healthy males, monoamine oxidase-A (MAO-A) genetic variants linked to low in vitro transcription (MAOA-L) are associated with structural abnormalities of the amygdala and OFC. However, it is currently unknown whether amygdala and OFC morphology in ASPD relate to MAO-A genetic polymorphisms. We studied 18 ASPD males with a history of violent offending and 20 healthy male controls. Genomic DNA was extracted from peripheral leukocytes to determine MAO-A genetic polymorphisms. Subjects underwent a T1-weighted MRI anatomical brain scan that provided vertex-wise measures of amygdala shape and surface area and OFC cortical thickness. We found that ASPD + PP subjects with MAOA-L exhibited decreased surface area in the right basolateral amygdala nucleus and increased surface area in the right anterior cortical amygdaloid nucleus versus healthy MAOA-L carriers. This study is the first to describe genotype-related morphological differences of the amygdala in a population marked by high aggression. Deficits in emotional regulation that contribute to the violence of ASPD + PP may relate to morphological changes of the amygdala under genetic control.

"Bad genes" & criminal responsibility

The genetics of the accused is trying to break into the courts. To date several candidate genes have been put forward and their links to antisocial behavior have been examined and documented with some consistency. In this paper, we focus on the so called "warrior gene", or the low-activity allele of the MAOA gene, which has been most consistently related to human behavior and specifically to violence and antisocial behavior. In preparing this paper we had two objectives. First, to summarize and analyze the current scientific evidence, in order to gain an in depth understanding of the state of the issue and determine whether a dominant line of generally accepted scientific knowledge in this field can be asserted. Second, to derive conclusions and put forward recommendations related to the use of genetic information, specifically the presence of the low-activity genotype of the MAOA gene, in modulation of criminal responsibility in European and US courts.

Understanding Youth Antisocial Behavior Using Neuroscience through a Developmental Psychopathology Lens: Review, Integration, and Directions for Research

Youth antisocial behavior (AB) is an important public health concern impacting perpetrators, victims, and society. Functional neuroimaging is becoming a more common and useful modality for understanding neural correlates of youth AB. Although there has been a recent increase in neuroimaging studies of youth AB and corresponding theoretical articles on the neurobiology of AB, there has been little work critically examining the strengths and weaknesses of individual studies and using this knowledge to inform the design of future studies. Additionally, research on neuroimaging and youth AB has not been integrated within the broader framework of developmental psychopathology. Thus, this paper provides an in-depth review of the youth AB functional neuroimaging literature with the following goals: 1. to evaluate how this literature has informed our understanding of youth AB, 2. to evaluate current neuroimaging studies of youth AB from a developmental psychopathology perspective with a focus on integrating research from neuroscience and developmental psychopathology, as well as placing this research in the context of other related areas (e.g., psychopathy, molecular genetics), and 3. to examine strengths and weaknesses of neuroimaging and behavioral studies of youth AB to suggest how future studies can develop a more informed and integrated understanding of youth AB.

Superior temporal sulcus and social cognition in dangerous drivers

Understanding the neural systems underpinning social cognition is a primary focus of contemporary social neuroscience. Using functional magnetic resonance imaging (fMRI), the present study asked if brain activity reflecting socio-cognitive processes differs between individuals according to their social behavior; namely, between a group of drivers with frequent traffic offenses and a group with none. Socio-cognitive processing was elicited by employing videos from a traffic awareness campaign, consisting of reckless and anti-social driving behavior ending in tragic consequences, and control videos with analogous driving themes but without such catastrophic endings. We investigated whether relative increases in brain function during the observation of these campaign stimuli compared with control videos differed between these two groups. To develop the results of our previous study we focused our analyses on superior temporal sulcus/gyrus (STS/STG). This revealed a bigger increase in brain activity within this region during the campaign stimuli in safe compared with dangerous drivers. Furthermore, by thematically coding drivers' verbal descriptions of the stimuli, we also demonstrate differences in STS reactivity according to drivers' scores on two indices of socio-cognitive processing: subjects' perceived consequences of actors' actions, and their affective evaluation of the clips. Our results demonstrate the influence of social behavior and socio-cognitive processing on STS reactivity to social stimuli, developing considerably our understanding of the role of this region in social cognition.

Resting-state synchrony in short-term versus long-term abstinent alcoholics

BACKGROUND

We previously reported that when compared with controls, long-term abstinent alcoholics (LTAA) have increased resting-state synchrony (RSS) of the inhibitory control network and reduced synchrony of the appetitive drive network, and hypothesized that these levels of synchrony are adaptive and support the behavioral changes required to maintain abstinence. In this study, we investigate whether these RSS patterns can be identified in short-term abstinent alcoholics (STAA).

METHODS

Resting-state functional magnetic resonance imaging data were collected from 27 STAA, 23 LTAA, and 23 nonsubstance abusing controls (NSAC). We examined baseline RSS using seed-based measures.

RESULTS

We found ordered RSS effects from NSAC to STAA and then to LTAA within both the appetitive drive and executive control networks: increasing RSS of the executive control network and decreasing RSS of the reward processing network. Finally, we found significant correlations between strength of RSS in these networks and (i) cognitive flexibility, and (ii) current antisocial behavior.

CONCLUSIONS

Findings are consistent with an adaptive progression of RSS from short- to long-term abstinence, so that, compared with normal controls, the synchrony (i) within the reward network progressively decreases, and (ii) within the executive control network progressively increases.

Linkage of functional and structural anomalies in the left amygdala of reactive-aggressive men

Amygdala structural and functional abnormalities have been associated to reactive aggression in previous studies. However, the possible linkage of these two types of anomalies has not been examined. We hypothesized that they would coincide in the same localizations, would be correlated in intensity and would be mediated by reactive aggression personality traits. Here violent (n = 25) and non-violent (n = 29) men were recruited on the basis of their reactive aggression. Callous-unemotional (CU) traits were also assessed. Gray matter concentration (gmC) and reactivity to fearful and neutral facial expressions were measured in dorsal and ventral amygdala partitions. The difference between responses to fearful and neutral facial expressions was calculated (F/N-difference). Violent individuals exhibited a smaller F/N-difference and gmC in the left dorsal amygdala, where a significant coincidence was found in a conjunction analysis. Moreover, the left amygdala F/N-difference and gmC were correlated to each other, an effect mediated by reactive aggression but not by CU. The F/N-difference was caused by increased reactivity to neutral faces. This suggests that anatomical anomalies within local circuitry (and not only altered input) may underlie the amygdala hyper-reactivity to social signals which is characteristic of reactive aggression.

Brains in context in the neurolaw debate: the examples of free will and "dangerous" brains

Will neuroscience revolutionize forensic practice and our legal institutions? In the debate about the legal implications of brain research, free will and the neural bases of antisocial or criminal behavior are of central importance. By analyzing frequently quoted examples for the unconscious determinants of behavior and antisocial personality changes caused by brain lesions in a wider psychological and social context, the paper argues for a cautious middle position: Evidence for an impending normative "neuro-revolution" is scarce and neuroscience may instead gradually improve legal practice in the long run, particularly where normative questions directly pertain to brain-related questions. In the conclusion the paper raises concerns that applying neuroscience methods about an individual's responsibility or dangerousness is premature at the present time and carries serious individual and societal risks. Putting findings from brain research in wider contexts renders them empirically investigable in a way that does not neglect psychological and social aspects of human mind and behavior.

Endogenous testosterone and cortisol modulate neural responses during induced anger control

Research with violent offenders and delinquent adolescents suggests that endogenous testosterone concentrations have the strongest positive correlations with violence among men who have low concentrations of cortisol. The present study tested the hypothesis that testosterone and cortisol would similarly interact to determine neural activation in regions supporting self-regulation in response to anger provocation. Nineteen healthy Asian male participants were insulted and asked to control their anger during functional magnetic resonance imaging (fMRI). When cortisol levels were low, testosterone positively correlated with activation in the dorsolateral prefrontal cortex (dlPFC) and thalamus, but not when cortisol levels were high. During induced anger control, functional connectivity was increased between the amygdala and a top-down prefrontal cortical control network. Moreover, the amygdala-PFC connectivity was strongest among those high in testosterone and low in cortisol. This research highlights a possible neural mechanism by which testosterone and cortisol may influence anger control.

Resting EEG deficits in accused murderers with schizophrenia

Empirical evidence continues to suggest a biologically distinct violent subtype of schizophrenia. The present study examined whether murderers with schizophrenia would demonstrate resting EEG deficits distinguishing them from both non-violent schizophrenia patients and murderers without schizophrenia. Resting EEG data were collected from five diagnostic groups (normal controls, non-murderers with schizophrenia, murderers with schizophrenia, murderers without schizophrenia, and murderers with psychiatric conditions other than schizophrenia) at a brain hospital in Nanjing, China. Murderers with schizophrenia were characterized by increased left-hemispheric fast-wave EEG activity relative to non-violent schizophrenia patients, while non-violent schizophrenia patients instead demonstrated increased diffuse slow-wave activity compared to all other groups. Results are discussed within the framework of a proposed left-hemispheric over-processing hypothesis specific to violent individuals with schizophrenia, involving left hemispheric hyperarousal deficits, which may lead to a homicidally violent schizophrenia outcome.

Neuropsychiatry of aggression

Aggression is a serious medical problem that can place both the patient and the health care provider at risk. Aggression can result from medical, neurologic, and/or psychiatric disorders. A comprehensive patient evaluation is needed. Treatment options include pharmacotherapy as well as nonpharmacologic interventions, both of which need to be individualized to the patient.

Neurocriminology

In the past several decades there has been an explosion of research into the biological correlates to antisocial behavior. This chapter reviews the state of current research on the topic, including a review of the genetics, neuroimaging, neuropsychological, and electrophysiological studies in delinquent and antisocial populations. Special attention is paid to the biopsychosocial model and gene-environment interactions in producing antisocial behavior.

Abnormal structural correlates of response perseveration in individuals with psychopathy

Structural deficits in the frontotemporal network have been shown in individuals with psychopathy and are posited to contribute to neuropsychological impairments such as response perseveration. However, no study to date has examined structural correlates of response perseveration in individuals with psychopathy. In this structural MRI study, the authors found higher correlations between increased response perseveration and reduced cortical thickness in the orbitofrontal and anterior temporal regions in individuals with psychopathy than in healthy-comparison subjects. The findings provide preliminary evidence suggesting potential contributions of frontotemporal structural deficits in neurocognitive impairment with perseveration in individuals with psychopathy.

From moral to legal judgment: the influence of normative context in lawyers and other academics

Various kinds of normative judgments are an integral part of everyday life. We extended the scrutiny of social cognitive neuroscience into the domain of legal decisions, investigating two groups, lawyers and other academics, during moral and legal decision-making. While we found activation of brain areas comprising the so-called 'moral brain' in both conditions, there was stronger activation in the left dorsolateral prefrontal cortex and middle temporal gyrus particularly when subjects made legal decisions, suggesting that these were made in respect to more explicit rules and demanded more complex semantic processing. Comparing both groups, our data show that behaviorally lawyers conceived themselves as emotionally less involved during normative decision-making in general. A group × condition interaction in the dorsal anterior cingulate cortex suggests a modulation of normative decision-making by attention based on subjects' normative expertise.

Lead and conduct problems: a meta-analysis

This meta-analysis examined the association between conduct problems and lead exposure. Nineteen studies on 8,561 children and adolescents were included. The average r across all 19 studies was .19 (p < .001), which is considered a medium effect size. Studies that assessed lead exposure using hair element analysis yielded considerably larger effect sizes than those that assessed lead exposure using blood, tooth, or bone lead levels. Excluding the 3 hair analysis studies, the average r was .15 (p < .001). The age of the participants did not significantly moderate the relation between lead exposure and conduct problems. Overall, the relation between lead exposure and conduct problems was strikingly similar in magnitude to the relation between lead exposure and decreased IQ.

Superior temporal gyrus volume in teenagers with first-presentation borderline personality disorder

This magnetic resonance imaging study investigated the superior temporal gyrus (STG) subregion volumes in 20 teenagers with first-presentation borderline personality disorder (BPD) and 20 healthy controls. While the STG volume early in the course of BPD did not differ from that of healthy controls, the BPD participants with violent episodes had a smaller left caudal STG volume compared with those without such episodes during the previous 6 months. Our preliminary findings might reflect the neurobiological heterogeneity of the disorder.

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.

Psychopathy and functional magnetic resonance imaging blood oxygenation level-dependent responses to emotional faces in violent patients with schizophrenia

BACKGROUND

Comorbidity between schizophrenia and psychopathy has been noted in violent patients in forensic settings. Both disorders are characterized by deficits in processing sad and fearful emotions, but there have been no imaging studies examining the impact of comorbid psychopathic traits on emotional information processing in violent patients with schizophrenia. We tested the hypothesis that violent patients with schizophrenia who had high psychopathy scores would show attenuated amygdala responses to emotional (particularly fearful) faces compared with those with low psychopathy scores.

METHODS

Twenty-four violent male patients with schizophrenia were categorized as high/low scorers based on the Psychopathy Checklist: Screening Version. Participants underwent functional magnetic resonance imaging during a block-designed implicit face affect processing task. In a region of interest approach, responses in the amygdala and prefrontal cortex were examined with contrasts between sad/fearful/angry/disgusted faces and neutral faces.

RESULTS

High psychopathy scorers exhibited reduced blood oxygenation level-dependent (BOLD) responses in the amygdala during exposure to fearful faces. Psychopathy scores, particularly the affective facets, correlated negatively with amygdala responses. The BOLD responses in the orbitofrontal cortex were negatively correlated with the lifestyle and antisocial facets of psychopathy during exposure to sad faces. Psychopathy scores were positively correlated with neural activation in amygdala and inferior prefrontal regions for disgust but negatively correlated for anger.

CONCLUSIONS

Patients with schizophrenia and high levels of psychopathic traits appear to have blunted amygdala responses to fearful faces. At a dimensional level, psychopathy subfacets show a differential relationship to functioning in amygdala-prefrontal circuitry.