Amygdala dysfunction attenuates frustration-induced aggression in psychopathic individuals in a non-criminal population

Psychopathy and medial frontal cortex: A systematic review reveals predominantly null relationships

Theories have posited that psychopathy is caused by dysfunction in the medial frontal cortex, including ventromedial prefrontal cortex (vmPFC), anterior cingulate cortex (ACC), and dorsomedial prefrontal cortex (dmPFC). Recent reviews have questioned the reproducibility of neuroimaging findings within this field. We conducted a systematic review to describe the consistency of magnetic resonance imaging (MRI) findings according to anatomical subregion (vmPFC, ACC, dmPFC), experimental task, psychopathy assessment, study power, and peak coordinates of significant effects. Searches of PsycInfo and MEDLINE databases produced 77 functional and 24 structural MRI studies that analyzed the medial frontal cortex in relation to psychopathy in adult samples. Findings were predominantly null (85.4 % of 1573 tests across the three medial frontal regions). Studies with higher power observed null effects at marginally lower rates. Finally, peak coordinates of significant effects were widely dispersed. The evidence failed to support theories positing the medial frontal cortex as a consistent neural correlate of psychopathy. Theory and methods in the field should be revised to account for predominantly null neuroimaging findings.

Early-life group size influences response inhibition, but not the learning of it, in Japanese quails

In complex social environments, animals benefit from suppressing inappropriate responses (known as Response Inhibition) to avoid conflicts and maintain group cohesion. Recent research suggests that an individual's early-life social environment can shape their response inhibition. However, these findings have mostly been correlational, and results vary across species. Furthermore, the role of learning is often overlooked when measuring response inhibition, despite its potential importance to understanding group differences. We investigated the effect of early-life group size, a key determinant of social complexity, on response inhibition in Japanese quails (Coturnix japonica), whilst taking the role of learning into account. Quails (n = 120) were raised in either small groups of five or large groups of 15 individuals. Response inhibition was assessed using the cylinder task. Up to ten trials were administered to assess whether the birds' responses changed with increasing experience of the task. Among the quails that completed ten trials, we found that those raised in large groups consistently spent less time pecking the cylinder than those raised in small groups. The quails' responses were also influenced by their body condition, food motivation and sex. Importantly, the quails learned to inhibit their responses - successful trials increased, and time spent pecking the cylinder decreased, across ten trials. However, learning rates did not differ between the treatment groups. These findings suggest that early-life social group size promotes the development of response inhibition in quails, but not their learning of it, during the cylinder task.

Social preferences and psychopathy in a sample of male prisoners-a pilot study

Social decisions are influenced by a person's social preferences. High psychopathy is defined by antisocial behaviour, but the relationship between psychopathy and social preferences remains unclear. In this study, we used a battery of economic games to study social decision-making and social preferences in relation to psychopathy in a sample of 35 male prison inmates, who were arrested for sexual and severe violent offenses (mean age = 39 years). We found no evidence for a relationship between social preferences (measured with the Dictator and Ultimatum Games, Social Value Orientation, and one-shot 2 × 2 games) and psychopathy (measured by the overall Hare Psychopathy Checklist-Revised score and both factors). These results are surprising but also difficult to interpret due to the small sample size. Our results contribute to the ongoing debate about psychopathy and social decision-making by providing crucial data that can be combined with future datasets to reach large sample sizes that can provide a more nuanced understanding about the relationship between psychopathy and social preferences.

How reliable are amygdala findings in psychopathy? A systematic review of MRI studies

The amygdala is a key component in predominant neural circuitry models of psychopathy. Yet, after two decades of neuroimaging research on psychopathy, the reproducibility of amygdala findings is questionable. We systematically reviewed MRI studies (81 of adults, 53 of juveniles) to determine the consistency of amygdala findings across studies, as well as within specific types of experimental tasks, community versus forensic populations, and the lowest- versus highest-powered studies. Three primary findings emerged. First, the majority of studies found null relationships between psychopathy and amygdala structure and function, even in the context of theoretically relevant tasks. Second, findings of reduced amygdala activity were more common in studies with low compared to high statistical power. Third, the majority of peak coordinates of reduced amygdala activity did not fall primarily within the anatomical bounds of the amygdala. Collectively, these findings demonstrate significant gaps in the empirical support for the theorized role of the amygdala in psychopathy and indicate the need for novel research perspectives and approaches in this field.

Craving for Gambling Predicts Income-Generating Offenses: A Pathways Model of a Japanese Prison Population

The links between gambling and criminal offenses have been frequently reported, but the pathways from gambling to a particular offense have not. Our study applied a pathways model to predict participants' income-generating, drug-related, and violent offenses stemming from their craving for gambling. The participants were 332 male inmates in a Japanese local prison. They answered questionnaires on gambling behavior, alcohol addiction, Internet addiction, impulsivity, and psychopathy. Their official records with information on their current offense, sentence length, number of imprisonments, and length of education were also analyzed. The results show that 38.55% (n = 128) of the participants had a probable gambling disorder, a rate of problem gambling at least four times higher than that among the general Japanese population. Furthermore, their craving for gambling predicted their income-generating offenses, but not their drug-related and violent offenses. Their craving for gambling can thus be linked to their financial issues, rather than their emotional and impulsive issues. The pathways model explained the path not only from addiction/psychopathy to gambling, but also from gambling to committing an income-generating offense.

Semantic and attentional networks in bilingual processing: fMRI connectivity signatures of translation directionality

Comparisons between backward and forward translation (BT, FT) have long illuminated the organization of bilingual memory, with neuroscientific evidence indicating that FT would involve greater linguistic and attentional demands. However, no study has directly assessed the functional interaction between relevant mechanisms. Against this background, we conducted the first fMRI investigation of functional connectivity (FC) differences between BT and FT. In addition to yielding lower behavioral outcomes, FT was characterized by increased FC between a core semantic hub (the left anterior temporal lobe, ATL) and key nodes of attentional and vigilance networks (left inferior frontal, left orbitofrontal, and bilateral parietal clusters). Instead, distinct FC patterns for BT emerged only between the left ATL and the right thalamus, a region implicated in automatic relaying of sensory information to cortical regions. Therefore, FT seems to involve enhanced coupling between semantic and attentional mechanisms, suggesting that asymmetries in cross-language processing reflect dynamic interactions between linguistic and domain-general systems.

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.

Psychopathic traits are related to diminished guilt aversion and reduced trustworthiness during social decision-making

Individuals with high levels of psychopathic tendencies tend to show a lack of guilt, a lack of empathic concern, and a disregard for the impact of their decisions on others. However, how guilt influences social decision-making for those with high psychopathic traits is still unknown. Here, we investigated how psychopathic traits relate to the capacity to acquire knowledge about social expectations, and to what extent guilt aversion affects subsequent decision-making. 63 participants completed self-report measures of psychopathy, and then played a modified Trust Game in the role of the Trustee. Results showed that participants’ self-reported beliefs about their partner’s expectations were largely predictive of the amount of money they returned to the partner. These decisions were negatively correlated with the PPI-I scores. Furthermore, participants’ degree of guilt aversion were negatively correlated with PPI total scores. Our findings suggest that individuals with higher psychopathic traits are indeed capable of understanding the expectations of others, but do not seem to directly utilise this knowledge in their social decision-making, and experience less anticipated guilt about this. The present study provides empirical evidence of intact social knowledge coupled with decreased reciprocity and diminished guilt aversion as levels of psychopathic traits increase.

A Systematic Literature Review of Neuroimaging of Psychopathic Traits

INTRODUCTION

Core psychopathy is characterized by grandiosity, callousness, manipulativeness, and lack of remorse, empathy, and guilt. It is often comorbid with conduct disorder and antisocial personality disorder (ASPD). Psychopathy is present in forensic as well as prison and general populations. In recent years, an increasing amount of neuroimaging studies has been conducted in order to elucidate the obscure neurobiological etiology of psychopathy. The studies have yielded heterogenous results, and no consensus has been reached.

AIMS

This study systematically reviewed and qualitatively summarized functional and structural neuroimaging studies conducted on individuals with psychopathic traits. Furthermore, this study aimed to evaluate whether the findings from different MRI modalities could be reconciled from a neuroanatomical perspective.

MATERIALS AND METHODS

After the search and auditing processes, 118 neuroimaging studies were included in this systematic literature review. The studies consisted of structural, functional, and diffusion tensor MRI studies.

RESULTS

Psychopathy was associated with numerous neuroanatomical abnormalities. Structurally, gray matter anomalies were seen in frontotemporal, cerebellar, limbic, and paralimbic regions. Associated gray matter volume (GMV) reductions were most pronounced particularly in most of the prefrontal cortex, and temporal gyri including the fusiform gyrus. Also decreased GMV of the amygdalae and hippocampi as well the cingulate and insular cortices were associated with psychopathy, as well as abnormal morphology of the hippocampi, amygdala, and nucleus accumbens. Functionally, psychopathy was associated with dysfunction of the default mode network, which was also linked to poor moral judgment as well as deficient metacognitive and introspective abilities. Second, reduced white matter integrity in the uncinate fasciculus and dorsal cingulum were associated with core psychopathy. Third, emotional detachment was associated with dysfunction of the posterior cerebellum, the human mirror neuron system and the Theory of Mind denoting lack of empathy and persistent failure in integrating affective information into cognition.

CONCLUSIONS

Structural and functional aberrancies involving the limbic and paralimbic systems including reduced integrity of the uncinate fasciculus appear to be associated with core psychopathic features. Furthermore, this review points towards the idea that ASPD and psychopathy might stem from divergent biological processes.

A systematic review examining the link between psychopathic personality traits, antisocial behavior, and neural reactivity during reward and loss processing

Antisocial Behavior (AB) has a tremendous societal cost, motivating investigation of the mechanisms that cause individuals to engage and persist in AB. Recent theories of AB emphasize the role of reward-related neural processes in the etiology of severe and chronic forms of AB, including antisocial personality disorder and psychopathy. However, no systematic reviews have evaluated the hypothesis that reward-related neural dysfunction is an etiologic factor in AB in adult samples. Moreover, it is unclear whether AB is linked to a hyper- or hyposensitive reward system and whether AB is related to neural sensitivity to losses. Thus, the current systematic review examined whether AB (including antisocial personality disorder) and psychopathic traits are related to neural reactivity during reward processing, loss processing, or both. Our review identified seven task-based functional MRI or functional connectivity studies that examined associations between neural response to reward and loss, and dimensional and categorical measures of adult AB and/or psychopathy. Across studies, there was evidence that AB is associated with variability in neural functioning during both reward and loss processing. In particular, impulsive-antisocial traits appeared to be specifically associated with hypersensitivity in the ventral striatum during the anticipation, but not the receipt, of rewards. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Impulsive aggression and response inhibition in attention-deficit/hyperactivity disorder and disruptive behavioral disorders: Findings from a systematic review

BACKGROUND

Although impulsive aggression (IA) and dysfunctional response inhibition (RI) are hallmarks of attention-deficit/hyperactivity disorder (ADHD) and disrupted behavioral disorders (DBDs), little is known about their shared and distinct deviant neural mechanisms.

AIMS AND METHODS

Here, we selectively reviewed s/fMRI ADHD and DBD studies to identify disorder-specific and shared IA and RI aberrant neural mechanisms.

RESULTS

In ADHD, deviant prefrontal and cingulate functional activity was associated with increased IA. Structural alterations were most pronounced in the cingulate cortex. Subjects with DBDs showed marked cortico-subcortical dysfunctions. ADHD and DBDs share similar cortico-limbic structural and functional alterations. RI deficits in ADHD highlighted hypoactivity in the dorso/ventro-lateral PFC, insula, and striatum, while the paralimbic system was primarily dysfunctional in DBDs. Across disorders, extensively altered cortico-limbic dysfunctions underlie IA, while RI was mostly associated with aberrant prefrontal activity.

CONCLUSION

Control network deficits were evidenced across clinical phenotypes in IA and RI. Dysfunctions at any level within these cortico-subcortical projections lead to deficient cognitive-affective control by ascribing emotional salience to otherwise irrelevant stimuli. The clinical implications of these findings are discussed.

Selective Fair Behavior as a Function of Psychopathic Traits in a Subclinical Population

Psychopathy is a group of personality traits that are associated with violations of social norms. Previous studies have suggested that people with psychopathic traits in subclinical populations do not necessarily display antisocial, self-defeating behaviors, and instead may strategically show adaptive behaviors in response to cues during reciprocal social interactions. Therefore, in the present study, we examined whether the association between psychopathic traits and unfair behavior can be moderated by a potential for punishment and social distance (anonymity), which are known to facilitate fair behavior. We focused on two psychopathic traits: primary and secondary psychopathy. Primary psychopathy is characterized by callousness, shallow affect, manipulation, and superficial charm. In contrast, secondary psychopathy is associated with impulsivity and lack of long-term goals, and is related to hostile behavior. A total of 348 undergraduate students determined the amounts of money that they would offer to strangers or friends at their university in hypothetical scenarios of the ultimatum game (UG) and the dictator game (DG). While gender affected decisions in the hypothetical scenarios of the DG, it did not interact with psychopathic traits. The score for primary psychopathy on the Levenson self-report psychopathy scale predicted unfair monetary offers to strangers in the DG, where participants could not be punished. However, compared with their offers in the DG, individuals with higher scores for primary psychopathy made larger offers in the UG, where low offers could trigger punishment from the recipient. Moreover, primary psychopathy did not decrease the amounts of offers in either game when the participant considered the recipient to be a friend. On the other hand, secondary psychopathy was not associated with differences in behavioral fairness depending on a potential for punishment or social distance. Based on these findings, we discuss strategic social skills as a function of primary psychopathy.

The Influence of Emotion on Fairness-Related Decision Making: A Critical Review of Theories and Evidence

Fairness-related decision making is an important issue in the field of decision making. Traditional theories emphasize the roles of inequity aversion and reciprocity, whereas recent research increasingly shows that emotion plays a critical role in this type of decision making. In this review, we summarize the influences of three types of emotions (i.e., the integral emotion experienced at the time of decision making, the incidental emotion aroused by a task-unrelated dispositional or situational source, and the interaction of emotion and cognition) on fairness-related decision making. Specifically, we first introduce three dominant theories that describe how emotion may influence fairness-related decision making (i.e., the wounded pride/spite model, affect infusion model, and dual-process model). Next, we collect behavioral and neural evidence for and against these theories. Finally, we propose that future research on fairness-related decision making should focus on inducing incidental social emotion, avoiding irrelevant emotion when regulating, exploring the individual differences in emotional dispositions, and strengthening the ecological validity of the paradigm.

Frontal and striatal alterations associated with psychopathic traits in adolescents

Neuroimaging research has demonstrated a range of structural deficits in adults with psychopathy, but little is known about structural correlates of psychopathic tendencies in adolescents. Here we examined structural magnetic resonance imaging (sMRI) data obtained from 14-year-old adolescents (n=108) using tensor-based morphometry (TBM) to isolate global and localized differences in brain tissue volumes associated with psychopathic traits in this otherwise healthy developmental population. We found that greater levels of psychopathic traits were correlated with increased brain tissue volumes in the left putamen, left ansa peduncularis, right superiomedial prefrontal cortex, left inferior frontal cortex, right orbitofrontal cortex, and right medial temporal regions and reduced brain tissues volumes in the right middle frontal cortex, left superior parietal lobule, and left inferior parietal lobule. Post hoc analyses of parcellated regional volumes also showed putamen enlargements to correlate with increased psychopathic traits. Consistent with earlier studies, findings suggest poor decision-making and emotional dysregulation associated with psychopathy may be due, in part, to structural anomalies in frontal and temporal regions whereas striatal structural variations may contribute to sensation-seeking and reward-driven behavior in psychopathic individuals. Future studies will help clarify how disturbances in brain maturational processes might lead to the developmental trajectory from psychopathic tendencies in adolescents to adult psychopathy.

Volitional control of the anterior insula in criminal psychopaths using real-time fMRI neurofeedback: a pilot study

This pilot study aimed to explore whether criminal psychopaths can learn volitional regulation of the left anterior insula with real-time fMRI neurofeedback. Our previous studies with healthy volunteers showed that learned control of the blood oxygenation-level dependent (BOLD) signal was specific to the target region, and not a result of general arousal and global unspecific brain activation, and also that successful regulation modulates emotional responses, specifically to aversive picture stimuli but not neutral stimuli. In this pilot study, four criminal psychopaths were trained to regulate the anterior insula by employing negative emotional imageries taken from previous episodes in their lives, in conjunction with contingent feedback. Only one out of the four participants learned to increase the percent differential BOLD in the up-regulation condition across training runs. Subjects with higher Psychopathic Checklist-Revised (PCL:SV) scores were less able to increase the BOLD signal in the anterior insula than their lower PCL:SV counterparts. We investigated functional connectivity changes in the emotional network due to learned regulation of the successful participant, by employing multivariate Granger Causality Modeling (GCM). Learning to up-regulate the left anterior insula not only increased the number of connections (causal density) in the emotional network in the single successful participant but also increased the difference between the number of outgoing and incoming connections (causal flow) of the left insula. This pilot study shows modest potential for training psychopathic individuals to learn to control brain activity in the anterior insula.

Functional Neuroscience of Psychopathic Personality in Adults

Psychopathy is a personality disorder that involves a constellation of traits including callous-unemotionality, manipulativeness, and impulsiveness. Here we review recent advances in the research of functional neural correlates of psychopathic personality traits in adults. We first provide a concise overview of functional neuroimaging findings in clinical samples diagnosed with the PCL-R. We then review studies with community samples that have focused on how individual differences in psychopathic traits (variously measured) relate to individual differences in brain function. Where appropriate, we draw parallels between the findings from these studies and those with clinical samples. Extant data suggest that individuals with high levels of psychopathic traits show lower activity in affect-processing brain areas to emotional/salient stimuli, and that attenuated activity may be dependent on the precise content of the task. They also seem to show higher activity in regions typically associated with reward processing and cognitive control in tasks involving moral processing, decision making, and reward. Furthermore, affective-interpersonal and lifestyle-antisocial facets of psychopathy appear to be associated with different patterns of atypical neural activity. Neuroimaging findings from community samples typically mirror those observed in clinical samples, and largely support the notion that psychopathy is a dimensional construct.

Towards a biopsychological understanding of costly punishment: the role of basal cortisol

Recent findings have documented a negative relation of basal endogenous cortisol and aggression after a provocation (i.e., reactive aggression) in humans. We build on these findings and investigated the relation of endogenous cortisol and reactive aggression in a social dilemma situation, that is, costly punishment of individuals who did not appropriately contribute to a common group project. Specifically, we predicted that basal cortisol is negatively related to costly punishment of uncooperative individuals. In the present study, basal cortisol was assessed prior to a public goods game with the option to punish other group members. In line with previous research on reactive aggression and basal cortisol, we found that basal cortisol was indeed negatively related to costly punishment. The findings are important for understanding costly punishment because this tendency has been documented as a possible basis for the evolution of cooperation.

Anger under control: neural correlates of frustration as a function of trait aggression

Antisocial behavior and aggression are prominent symptoms in several psychiatric disorders including antisocial personality disorder. An established precursor to aggression is a frustrating event, which can elicit anger or exasperation, thereby prompting aggressive responses. While some studies have investigated the neural correlates of frustration and aggression, examination of their relation to trait aggression in healthy populations are rare. Based on a screening of 550 males, we formed two extreme groups, one including individuals reporting high (n=21) and one reporting low (n=18) trait aggression. Using functional magnetic resonance imaging (fMRI) at 3T, all participants were put through a frustration task comprising unsolvable anagrams of German nouns. Despite similar behavioral performance, males with high trait aggression reported higher ratings of negative affect and anger after the frustration task. Moreover, they showed relatively decreased activation in the frontal brain regions and the dorsal anterior cingulate cortex (dACC) as well as relatively less amygdala activation in response to frustration. Our findings indicate distinct frontal and limbic processing mechanisms following frustration modulated by trait aggression. In response to a frustrating event, HA individuals show some of the personality characteristics and neural processing patterns observed in abnormally aggressive populations. Highlighting the impact of aggressive traits on the behavioral and neural responses to frustration in non-psychiatric extreme groups can facilitate further characterization of neural dysfunctions underlying psychiatric disorders that involve abnormal frustration processing and aggression.

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.

Distinct neural activation patterns underlie economic decisions in high and low psychopathy scorers

Psychopathic traits affect social functioning and the ability to make adaptive decisions in social interactions. This study investigated how psychopathy affects the neural mechanisms that are recruited to make decisions in the ultimatum game. Thirty-five adult participants recruited from the community underwent functional magnetic resonance imaging scanning while they performed the ultimatum game under high and low cognitive load. Across load conditions, high psychopathy scorers rejected unfair offers in the same proportion as low scorers, but perceived them as less unfair. Among low scorers, the perceived fairness of offers predicted acceptance rates, whereas in high scorers no association was found. Imaging results revealed that responses in each group were associated with distinct patterns of brain activation, indicating divergent decision mechanisms. Acceptance of unfair offers was associated with dorsolateral prefrontal cortex activity in low scorers and ventromedial prefrontal cortex activity in high scorers. Overall, our findings point to distinct motivations for rejecting unfair offers in individuals who vary in psychopathic traits, with rejections in high psychopathy scorers being probably induced by frustration. Implications of these results for models of ventromedial prefrontal cortex dysfunction in psychopathy are discussed.