Psychopaths Show Enhanced Amygdala Activation during Fear Conditioning

The impact of psychopathic traits on anxiety-related behaviors in a mixed reality environment

There is an ongoing debate about anxiety deficits in psychopathy and their possible impact on individual behavior. Data on actual anxiety- and threat-related behavior associated with psychopathy is still limited. We performed a mixed reality study using the elevated plus-maze (EPM) in a non-clinical sample (N = 160) to test anxiety-related behavior in relation to psychopathic personality traits measured through the Brief Questionnaire of Psychopathic Personality Traits (FPP). The psychopathy sum score correlated significantly with all measures of anxiety-related behavior on the EPM. Sensation seeking, but not general levels of acrophobia was moreover associated with psychopathic traits. Multivariate analyses revealed that the subscales Fearlessness and Lack of Empathy of the FPP predicted anxious behavior. Our findings are the first to demonstrate the relationship between psychopathic traits and actual behavior in an anxiety-inducing environment. This supports the low-anxiety hypothesis in psychopathy research. Implications for potentially harmful or risky behavior are discussed.

Parsing neural circuits of fear learning and extinction across basic and clinical neuroscience: Towards better translation

Over the past decades, studies of fear learning and extinction have advanced our understanding of the neurobiology of threat and safety learning. Animal studies can provide mechanistic/causal insights into human brain regions and their functional connectivity involved in fear learning and extinction. Findings in humans, conversely, may further enrich our understanding of neural circuits in animals by providing macroscopic insights at the level of brain-wide networks. Nevertheless, there is still much room for improvement in translation between basic and clinical research on fear learning and extinction. Through the lens of neural circuits, in this article, we aim to review the current knowledge of fear learning and extinction in both animals and humans, and to propose strategies to fill in the current knowledge gap for the purpose of enhancing clinical benefits.

Psychopathy is associated with an exaggerated attention bottleneck: EEG and behavioral evidence from a dual-task paradigm

Psychopathy is a personality disorder associated with a chronic disregard for the welfare of others. The attention bottleneck model of psychopathy asserts that the behavior of individuals higher on psychopathy is due to an exaggerated attention bottleneck that constrains all information processing, regardless of the information's potential goal-relevance. To date, the majority of research on the attention bottleneck model of psychopathy conceptually applied the tenets of the model but did not implement methods that directly test an exaggeration of the bottleneck in psychopathy. Accordingly, the presence of an exaggerated bottleneck, the exact expression of that bottleneck, and its potential mechanistic relevance for behavior in individuals higher on psychopathy remains untested. To address these gaps, a sample of 78 male community members, evaluated for psychopathic traits using the Self-Report Psychopathy-III scale, completed an EEG-based dual-task paradigm examining short stimulus onset asynchrony (SOA; 300 ms), long SOA (1,100 ms), and single-task baseline conditions. Additionally, participants were asked about their frequency of real-world risky, impulsive, and antisocial behaviors. Psychopathy was associated with slower reaction times to second targets (T2s) presented during the dual-task conditions, relative to the baseline condition. Psychopathy also was associated with blunted P300 responses, a neural index of stimulus evaluation, across all types of T2 events. Finally, bottleneck-related interference during the short SOA events mediated the relationship between psychopathy and real-world behavior. These findings suggested that individuals higher on psychopathy exhibit an exaggerated bottleneck which produces intense and long-lasting interference, impacting all information processing and partially contributing to their maladaptive behavior.

Structural equation modeling of the associations between amygdala activation, personality, and internalizing, externalizing symptoms of psychopathology

There is an expanding literature on the theoretical and empirical connections between personality and psychopathology, and their shared neurobiological correlates. Recent cybernetic theories of personality and psychopathology, as well as affective neuroscience theory, provide grounding for understanding neurobiological-personality-psychopathology (NPP) associations. With the emergence of large sample datasets (e.g., Human Connectome Project) advanced quantitative modeling can be used to rigorously test dynamic statistical representations of NPP connections. Also, research suggests that these connections are influenced by sex, and large samples provide the opportunity to examine how NPP associations might be moderated by sex. The current study used a large sample from the Duke Neurogenetics Study (DNS) to examine how amygdala activation to facial expressions was linked with self-report of personality traits and clinical interviews of internalizing and externalizing symptoms of psychopathology. Structural equation modeling results revealed direct associations of amygdala activation with personality trait expression, as well as indirect associations (though personality) with symptoms of psychopathology. Moreover, the NPP links were moderated by sex. The current results are in line with research that identifies a broader role played by the amygdala in personality and provide potential insights for continued research in personality neuroscience and recent theories on the neurobiology of personality.

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.

Functional neural correlates of psychopathy: a meta-analysis of MRI data

Neuroimaging studies over the last two decades have begun to specify the neurobiological correlates of psychopathy, a personality disorder that is strongly related to criminal offending and recidivism. Despite the accumulation of neuroimaging studies of psychopathy, a clear and comprehensive picture of the disorder's neural correlates has yet to emerge. The current study is a meta-analysis of functional MRI studies of psychopathy. Multilevel kernel density analysis was used to identify consistent findings across 25 studies (460 foci) of task-related brain activity. Psychopathy was associated with increased task-related activity predominantly in midline cortical regions overlapping with the default mode network (dorsomedial prefrontal cortex, posterior cingulate, and precuneus) as well as medial temporal lobe (including amygdala). Psychopathy was related to decreased task-related activity in a region of the dorsal anterior cingulate cortex overlapping with the salience network. These findings challenge predominant theories of amygdala hypoactivity and highlight the potential role of hyperactivity in medial default mode network regions and hypoactivity in a key node of the salience network during task performance in psychopathy.

Psychopathy is associated with shifts in the organization of neural networks in a large incarcerated male sample

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Psychopathy is linked to disruptions in neural information processing.

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Graph analysis revealed that psychopathy impacts neural network organization.

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Psychopathy is linked to a hyper-efficiently organized dorsal attention network.

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Subcortical structures are less central to neural communication in psychopathy.

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No psychopathy differences were found in default or salience network graph metrics.

Psychopathy is a personality disorder defined by antisocial behavior paired with callousness, low empathy, and low interpersonal emotions. Psychopathic individuals reliably display complex atypicalities in emotion and attention processing that are evident when examining task performance, activation within specific neural regions, and connections between regions. Recent advances in neuroimaging methods, namely graph analysis, attempt to unpack this type of processing complexity by evaluating the overall organization of neural networks. Graph analysis has been used to better understand neural functioning in several clinical disorders but has not yet been used in the study of psychopathy. The present study applies a minimum spanning tree graph analysis to resting-state fMRI data collected from male inmates assessed for psychopathy with the Hare Psychopathy Checklist-Revised (n = 847). Minimum spanning tree analysis provides several metrics of neural organization optimality (i.e., the effectiveness, efficiency, and robustness of neural network organization). Results show that inmates higher in psychopathy exhibit a more efficiently organized dorsal attention network (β = =0.101, p_corrected = =0.018). Additionally, subcortical structures (e.g., amygdala, caudate, and hippocampus) act as less of a central hub in the global flow of information in inmates higher in psychopathy (β = =−0.104, p_corrected = =0.048). There were no significant effects of psychopathy on neural network organization in the default or salience networks. Together, these shifts in neural organization suggest that the brains of inmates higher in psychopathy are organized in a fundamentally different way than other individuals.

Neural Mechanisms Involved in Social Conformity and Psychopathic Traits: Prediction Errors, Reward Processing and Saliency

Aligning behavior in favor of group norms, i.e., social conformity, can help to successfully adapt to uncertain environments and may result in social approval. This may lead to enhanced feelings of belongingness and is found to be associated with reward-related activations in the brain. Individuals high on psychopathic traits violate group norms regularly. Yet, it is unclear how psychopathic traits are related to neural mechanisms involved in social conformity. This functional magnetic resonance imaging (fMRI) study includes 42 healthy females scoring low or high on the Psychopathic Personality Inventory questionnaire (PPI). Participants were asked to rate the trustworthiness of 120 faces while lying in the scanner. After rating each face, participants were presented with the group rating of European students. In an unanticipated second part participants rated all faces again, allowing us to focus on two main contrasts: (1) “Social conflict”: group opinion in conflict with the participant’s rating vs. group opinion aligned with participant rating; and (2) “Conformity”: conflict trials followed by conformity vs. conflict trials followed by non-conformity. Behaviorally, the two groups showed similar conformity behavior. fMRI results showed that both groups activated the nucleus accumbens (NAc) following alignment, suggesting the central role of prediction errors and reward. The data also showed a significant interaction between group and conformity in the amygdala. Following conflicts, females scoring low on psychopathic traits showed a trend in enhanced amygdala activation for conformity relative to non-conformity. Additionally, results showed a trend significant group effect for non-conformity. Females scoring high on psychopathic traits showed more activation for non-conformity compared to females scoring low on psychopathic traits, suggesting altered emotional salience of experiencing conflict depending on psychopathic traits. Taken together, these results support the importance of investigating the role of relevant traits in adaptive behavior when facing uncertain social situations and the neural mechanisms involved in this process.

Amygdala functioning during threat acquisition and extinction differentiates antisocial subtypes

Extensive work implicates abnormal amygdala response during threatening stimuli in youth with antisocial behaviour. However, no research has examined whether youth identified in Primary and Secondary psychopathy subtypes would show differences in amygdala activity in response to threat acquisition and extinction. Latent profile analysis (LPA) was used to identify distinct antisocial groups based on participants' scores on callous-unemotional (CU) traits, anxiety, and familial abuse in a sample of 136 high-risk adolescents (mean age = 17.7, SD = 1.6; 86% male). Functional MRI was then used to assess amygdala activation patterns during a classical differential delay threat-conditioning task. In addition to the Primary and Secondary subtypes, we identified groups mainly high on anxiety and others who were mainly high on abuse. Participants in the Primary group showed lower right amygdala activity in response to neutral male faces compared to the low, Anxious, and Secondary groups, whereas participants in the group with history of abuse exhibited higher right amygdala activity during threat acquisition compared to the rest of the groups. During threat extinction, the Primary group showed lower right amygdala activity compared to the Secondary and abuse groups. This is the first study to reveal amygdala activation in identified psychopathy-related variants during threat conditioning. We found that stratifying the sample based on the identified variants revealed amygdala functioning patterns that furthered our understanding of emotion-based deficits among high-risk adolescents.

Capacity for upregulation of emotional processing in psychopathy: all you have to do is ask

Historically, psychopathic individuals have been described as suffering a chronic hyporesponsivity to negatively valent stimuli. However, while a wide body of empirical work indicates that the psychopath does not manifest normal reactivity to emotional stimuli, it does not similarly indicate that they cannot do so. To attempt to differentiate these alternatives, the current functional magnetic resonance imaging (fMRI) study evaluated the extent to which offenders with varying PCL-R scores could up- (or down-) regulate their neural response to negatively valent stimuli. Participants were asked to either watch negatively- and neutrally-valent images naturally (passive-processing), or to try to increase or decrease their emotional response to the images (instructed-processing). During passive processing, high-psychopathy offenders showed reduced activity compared to both low- and mid-psychopathic offenders through a majority of emotion-relevant regions. However, when participants were instructed to try to increase their emotional response all groups showing increased activity throughout relevant regions, including left insula, orbitofrontal cortex and anterior cingulate/medial frontal cortex (ACC/mFC). Comparison of participants' subjective emotion ratings indicated that all groups showed symmetry between their neural/subjective emotion metrics, and the high-psychopathy group may have showed the greatest such symmetry. These findings suggest that psychopathic individuals may be capable of manifesting emotional reactivity to negatively valent stimuli, at least under certain conditions. Relevance for traditional and developing models of psychopathy is discussed in turn.

Cortico-limbic connectivity changes following fear extinction and relationships with trait anxiety

Fear extinction is a powerful model of adaptive and anxiety-related maladaptive fear inhibition. This learning process is dependent upon plastic interactions between the amygdala, the anterior midcingulate cortex (aMCC), the hippocampus, and the ventromedial prefrontal cortex (vmPFC). With regard to the amygdala, the basolateral (BLA) and centromedial amygdala (CMA) serve unique roles in fear extinction. In a large sample (N = 91), the current study examined pre- to post-extinction changes in resting state functional connectivity (RSFC) of fear inhibition and expression pathways. We also examined how trait anxiety and extinction performance were associated with extinction-related changes within these neural pathways. We found stronger pre- to post-extinction RSFC in pathways known to play a role in the down-regulation of fear responses (BLA-hippocampus, aMCC-hippocampus, CMA-hippocampus, CMA-aMCC). We also found that trait anxiety was associated with strengthening of a BLA–aMCC circuit supporting fear expression following extinction learning. Furthermore, we found that physiological indices of poorer extinction learning were linked to weaker pre- to post-extinction RSFC of a BLA–hippocampus pathway important for fear extinction consolidation. Our results highlight the network changes that occur during extinction, the separable role of CMA and BLA-based circuitry and a key pathway linked to risk for anxiety pathology.

The contribution of brain imaging to the understanding of psychopathy

Psychopathy is a personality type characterized by both callous emotional dysfunction and deviant behavior that affects society in the form of actions that harm others. Historically, researchers have been concerned with seeking data and arguments to support a neurobiological foundation of psychopathy. In the past few years, increasing research has begun to reveal brain alterations putatively underlying the enigmatic psychopathic personality. In this review, we describe the brain anatomical and functional features that characterize psychopathy from a synthesis of available neuroimaging research and discuss how such brain anomalies may account for psychopathic behavior. The results are consistent in showing anatomical alterations involving primarily a ventral system connecting the anterior temporal lobe to anterior and ventral frontal areas, and a dorsal system connecting the medial frontal lobe to the posterior cingulate cortex/precuneus complex and, in turn, to medial structures of the temporal lobe. Functional imaging data indicate that relevant emotional flow breakdown may occur in both these brain systems and suggest specific mechanisms via which emotion is anomalously integrated into cognition in psychopathic individuals during moral challenge. Directions for future research are delineated emphasizing, for instance, the relevance of further establishing the contribution of early life stress to a learned blockage of emotional self-exposure, and the potential role of androgenic hormones in the development of cortical anomalies.

Prefrontal-limbic Functional Connectivity during Acquisition and Extinction of Conditioned Fear

This study is a new analysis to obtain novel metabolic data on the functional connectivity of prefrontal-limbic regions in Pavlovian fear acquisition and extinction of tone-footshock conditioning. Mice were analyzed with the fluorodeoxyglucose (FDG) autoradiographic method to metabolically map regional brain activity. New FDG data were sampled from the nuclei of the habenula and other regions implicated in aversive conditioning, such as infralimbic cortex, amygdala and periaqueductal gray regions. The activity patterns among these regions were inter-correlated during acquisition, extinction or pseudorandom training to develop a functional connectivity model. Two subdivisions of the habenular complex showed increased activity after acquisition relative to extinction, with the pseudorandom group intermediate between the other two groups. Significant acquisition activation effects were also found in centromedial amygdala, dorsomedial and ventrolateral periaqueductal gray. FDG uptake increases during extinction were found only in dorsal and ventral infralimbic cortex. The overall pattern of activity correlations between these regions revealed extensive but differential functional connectivity during acquisition and extinction training, with less functional connectivity found after pseudorandom training. Interestingly, habenula nuclei showed a distinct pattern of inter-correlations with amygdala nuclei during extinction. The functional connectivity model revealed changing interactions among infralimbic cortex, amygdala, habenula and periaqueductal gray regions through the stages of Pavlovian fear acquisition and extinction. This study provided new data on the contributions of the habenula to fear conditioning, and revealed previously unreported infralimbic-amygdala-habenula-periaqueductal gray interactions implicated in acquisition and extinction of conditioned fear.