Neural Mechanisms Underlying Affective Theory of Mind in Violent Antisocial Personality Disorder and/or Schizophrenia

What do we know now about evidence-based treatment for psychosis and aggressive behaviour or criminality that we did not know when community care was implemented?

PURPOSE

Community care replaced institutional care for people with psychosis without guidance about what constituted effective treatment. In a Swedish birth cohort, many of those who developed schizophrenia or bipolar disorder as community care was being implemented were subsequently convicted of violent and non-violent crimes. Studies from other countries that were implementing community care at this time also reported elevated proportions of patients acquiring criminal convictions. Since community care was first implemented, much has been learned about factors that promote and treatments that limit aggressive/antisocial behaviour/criminality (AABC) among people with psychosis. Without the benefit of this knowledge, did mental health policy and practices that were in place as the asylums were closed inadvertently contribute to criminality?

MATERIAL AND METHODS

This article provides a narrative review of current evidence of effective treatments and management strategies to reduce AABC among patients with psychosis.

RESULTS

Reductions in AABC are associated with stable contact with psychiatric services, second-generation antipsychotic medication, clozapine for patients with schizophrenia and elevated levels of hostility and/or a history of childhood conduct disorder, abstinence from substances, avoidance of trauma, and constant monitoring of both illness symptoms and AABC.

CONCLUSIONS

Failure to adopt evidence-based practices allows the problem of AABC to persist, prevents patients from experiencing independent, safe, community tenure, and puts those around them at risk. Many challenges remain, including implementing effective assessment and interventions at first-episode and convincing patients with antisocial attitudes and behaviours to participate in treatment programs to reduce AABC and to learn prosocial behaviours.

Court-ordered forensic psychiatry treatment in prison: determinants of outcome and risk mitigation

Background

Court-ordered forensic psychiatry treatments (COT) are specifically designed to reduce the risk of violence in mentally disordered offenders. Given their high costs and ethical issues, mental health professionals need admission criteria to be able to select those candidates with optimal benefit. This study analyses offender-related and treatment-related determinants of COT outcome and risk mitigation.

Methods

This two-year longitudinal study assessed the evolution of 117 adult offenders admitted to a specialized medium-security forensic psychiatry clinic. Treatment outcome included court-ordered discharge locations and the Historical Clinical Risk Management (HCR) score evolution. Treatment progress was assessed every six months across five time-points including measures of protective factors, work rehabilitation and security. Outcome determinants included psychiatric diagnosis and type of offence.

Results

Discharge locations are predicted by pre-treatment risk level. Lower HCR scores are associated with discharge into low-security psychiatry wards independently of the psychiatric diagnosis. Risk reduction follows diagnosis-specific and offense-related patterns and reveals that mentally disordered offenders with Cluster B personality disorders or those sentenced for drug crimes are significantly less prone to benefit from COT.

Conclusions

Our findings indicate that criminological characteristics at baseline as well as diagnosis of personality disorders are the main determinants of treatment outcome in our care setting. Inmates with concomitant higher violence risk at baseline and presence of Cluster B personality disorders might benefit the least from court-ordered forensic inpatient psychiatric care in prison.

Task-related brain activation associated with violence in patients with schizophrenia: A meta-analysis

This study investigates specific changes in brain function during cognitive and emotional tasks in patients with schizophrenia and a history of violence (VSCZ) compared with non-violent patients with schizophrenia and healthy controls. A comprehensive literature search was conducted at the Web of Science, Medline, and PubMed. Ten studies met the inclusion criteria. In which, eight studies compared brain activation between patients with VSCZ and non-violent patients with schizophrenia, and the former exhibited increased activation at the middle occipital gyrus and rectus compared with the latter. Seven studies compared brain activation between patients with VSCZ and controls, and the former exhibited increased activation at the anterior cingulate cortex, cerebellum VI region, lingual gyrus and fusiform. Subgroup analysis in five studies performing emotional tasks revealed that patients with VSCZ showed increased activation at the middle occipital gyrus compared with non-violent patients with schizophrenia. Our findings suggest that abnormal emotion perception and regulation significantly contribute to the increased risk of violence in patients with schizophrenia. Notably, the middle occipital gyrus and rectus emerge as key neurophysiological correlates associated with this phenomenon.

Neuroimaging and Brain-Based Markers Identifying Neurobiological Markers Associated With Criminal Behaviour, Personality Disorders, and Mental Health: A Narrative Review

We begin the review by pointing to the common stigma associated with mental health issues, which often derives from a lack of understanding or incomplete knowledge. Neurobiological research provides us with a new lens to help challenge and dispel common assumptions and misunderstandings and gives an understanding of sexual behaviours that influence society. As such, it generates substantial evidence for the structural and functional asymmetry of the brains of individuals with mental disorders. However, this type of representation poses many challenges to traditional thinking and constantly provokes change in perspective and empathy towards those individuals. In the review, we go deeper into the effects of neurobiological findings on understanding criminal behaviours and personality disorders, looking further beyond behavioural health. These problems, which were once mainly discussed as moral ones or viewed from the perspective of character flaws, are analysed today through neurological considerations pointing to their complexity. When the root of bipolar disorder is revealed to be neurological, society will react with more information and understanding, hence reducing the stigmatisation and discrimination meted out to people with these problems. At a macro level, findings from neurobiology affect society in ways that go beyond individuals; social attitudes, laws, and policies about the services rendered are influenced. Operating as a catalyst within the community, neurobiological research helps to initiate social change through the creation of an informed, understanding public forum. Thus, it creates broader value for those dealing with behavioural and mental health challenges. The first and most important question of this narrative review is focused on identifying identifiable neurobiological markers that are closely related to criminal conduct, personality disorders, and mental health disorders. Through this review, we aim to present detailed insights into the neurological foundations that anchor these phenomena via a narrative analysis of contemporary literature. The potential implications are finding problems early to apply specific treatment and learning an advanced strategy for social attitudes. This will promote a more humanistic approach based on adequate information on the behavioural and mental health issues involved.

Criminal behaviors: A theory of mind problem?

Theory of mind (ToM) has been addressed in relation to functional alterations of certain brain regions and their connections. The objective is to evaluate ToM in imprisoned criminal offenders and to analyze their relationship with the functions linked to the prefrontal cortex according to their expression in neuropsychological tests. The sample was composed of 52 subjects. 27 committed instrumental homicides and 25 crimes of sale and/or possession of narcotics. A control group was taken, 19 healthy subjects at liberty. The Faux-Pas (FP) and the Reading the Mind in the Eyes tests were used. A neuropsychological battery of executive functions and functions related to the frontal lobes and Hare's Psychopathy Checklist-Revised (PCL-R) was also applied. The criminal groups have comparable performances in all measures. The control group (in freedom) showed higher performance, with statistical significance, in the Faux-Pas test. Moderate negative correlations were found between the FP and the PCL-R. A distinction between affective and cognitive ToM could be affirmed, with people deprived of liberty presenting deficient functioning in the cognitive ToM test. This difference in performance could be linked to the disruptive event with the social norm and not so much with the violent homicide act itself.

Genome-wide association study of antisocial personality disorder diagnostic criteria provides evidence for shared risk factors across disorders

INTRODUCTION

While progress has been made in determining the genetic basis of antisocial behaviour, little progress has been made for antisocial personality disorder (ASPD), a condition that often co-occurs with other psychiatric conditions including substance use disorders, attention deficit hyperactivity disorder (ADHD), and anxiety disorders. This study aims to improve the understanding of the genetic risk for ASPD and its relationship with other disorders and traits.

METHODS

We conducted a genome-wide association study (GWAS) of the number of ASPD diagnostic criteria data from 3217 alcohol-dependent participants recruited in the UK (UCL, N = 644) and the USA (Yale-Penn, N = 2573).

RESULTS

We identified rs9806493, a chromosome 15 variant, that showed a genome-wide significant association ( Z -score = -5.501, P = 3.77 × 10 -8 ) with ASPD criteria. rs9806493 is an eQTL for SLCO3A1 (Solute Carrier Organic Anion Transporter Family Member 3A1), a ubiquitously expressed gene with strong expression in brain regions that include the anterior cingulate and frontal cortices. Polygenic risk score analysis identified positive correlations between ASPD and smoking, ADHD, depression traits, and posttraumatic stress disorder. Negative correlations were observed between ASPD PRS and alcohol intake frequency, reproductive traits, and level of educational attainment.

CONCLUSION

This study provides evidence for an association between ASPD risk and SLCO3A1 and provides insight into the genetic architecture and pleiotropic associations of ASPD.

Psychopathic Traits and Theory of Mind Task Performance: A Systematic Review and Meta-analysis

This meta-analysis aims to examine the relationship between psychopathic traits and theory of mind (ToM), which is classically and broadly defined as competency in representing and attributing mental states such as emotions, intentions, and beliefs to others. Our search strategy gathered 142 effect sizes, from 42 studies, with a total sample size of 7463 participants. Random effects models were used to analyze the data. Our findings suggested that psychopathic traits are associated with impaired ToM task performance. This relationship was not moderated by age, population, psychopathy measurement (self-report versus clinical checklist) or conceptualization, or ToM task type (cognitive versus affective). The effect also remained significant after excluding tasks that did not require the participant to 1) mentalize or 2) differentiate self and other perspectives. However, interpersonal/affective traits were associated with a more pronounced impairment in ToM task performance compared to lifestyle/antisocial traits. Future research should investigate the effects of distinct psychopathy facets that will allow for a more precise understanding of the social-cognitive bases of relevant clinical presentations in psychopathy.

Disentangling the Relationships Between the Clinical Symptoms of Schizophrenia Spectrum Disorders and Theory of Mind: A Meta-analysis

BACKGROUND AND HYPOTHESIS

Previous studies have suggested links between clinical symptoms and theory of mind (ToM) impairments in schizophrenia spectrum disorders (SSD), but it remains unclear whether some symptoms are more strongly linked to ToM than others.

STUDY DESIGN

A meta-analysis (Prospero; CRD42021259723) was conducted to quantify and compare the strength of the associations between ToM and the clinical symptoms of SSD (Positive, Negative, Cognitive/Disorganization, Depression/Anxiety, Excitability/Hostility). Studies (N = 130, 137 samples) including people with SSD and reporting a correlation between clinical symptoms and ToM were retrieved from Pubmed, PsycNet, Embase, Cochrane Library, Science Direct, Proquest, WorldCat, and Open Gray. Correlations for each dimension and each symptom were entered into a random-effect model using a Fisher's r-to-z transformation and were compared using focused-tests. Publication bias was assessed with the Rosenthal failsafe and by inspecting the funnel plot and the standardized residual histogram.

STUDY RESULTS

The Cognitive/Disorganization (Zr = 0.28) and Negative (Zr = 0.24) dimensions revealed a small to moderate association with ToM, which was significantly stronger than the other dimensions. Within the Cognitive/Disorganization dimension, Difficulty in abstract thinking (Zr = 0.36) and Conceptual disorganization (Zr = 0.39) showed the strongest associations with ToM. The association with the Positive dimension (Zr = 0.16) was small and significantly stronger than the relationship with Depression/Anxiety (Zr = 0.09). Stronger associations were observed between ToM and clinical symptoms in younger patients, those with an earlier age at onset of illness and for tasks assessing a combination of different mental states.

CONCLUSIONS

The relationships between Cognitive/Disorganization, Negative symptoms, and ToM should be considered in treating individuals with SSD.

Decision-making under risk and theory of mind in adolescent offenders in provisional deprivation of liberty

INTRODUCTION

Delinquent behaviors are risky behaviors that increase during puberty and reach their highest peak in late adolescence. It has been proposed that poor decision-making and theory of mind (ToM) are key cognitive processes implicated with delinquency during adolescence, affecting evaluation of risks and impairing appreciation of social norms. Nevertheless, it is not yet clear whether adolescent offenders who are subjected to provisional deprivation of liberty due to conflict with the law (adolescents in conflict with the law [ACL]) might, in fact, present a specific profile with regard to these cognitive processes.

OBJECTIVES

To assess deliberative decision-making and ToM among adolescents in conflict with the law and adolescents not in conflict with the law.

METHODS

The sample comprised 62 participants: ACL (n = 29) and a control group (CG) (n = 33). ToM was assessed with the Reading the Mind in the Eyes Test (RMET) and decision-making was assessed with the Columbia Card Task (CCT). Substance use, callous-unemotional traits, childhood maltreatment, and intelligence quotient (IQ) were also assessed.

RESULTS

ACL had more ToM errors for negative mental states in comparison to CG, but not for error rates concerning neutral and positive mental states. With regards to decision-making, our results suggest that ACL group members did not vary their behavior based on the available information and that the risk information had an opposite effect on the number of cards chosen (risk-taking behavior) when compared to CG.

CONCLUSION

These findings have important implications for development of interventions for these adolescents, suggesting that they tend to learn little from negative outcomes and have reduced capacity to process negative emotions.

Abnormalities in electroencephalographic microstates among violent patients with schizophrenia

Schizophrenia is often associated with a remarkably increased risk of violence, which has become a public health concern and brought a great economic burden. Recent studies have reported changes in the electroencephalograms (EEG) of patients with schizophrenia. The evidence for an association between EEG and violence in patients with schizophrenia is not conclusive. This study aimed to investigate EEG microstates in violent patients with schizophrenia. Forty-three violent patients with schizophrenia (the VS group) and 51 non-violent patients with schizophrenia (the NVS group) were included, and their EEG microstates were recorded using 21-Channel EEG recordings. The two groups were compared for differences of four microstate classes (A-D) with regards to three microstate parameters (duration, occurrence, and coverage). Compared with the NVS group, the VS group exhibited increased duration, occurrence, and coverage of microstate class A and decreased occurrence of microstate class B. The VS group also had lower probabilities of transitions from "B to C" and from "C to B", as compared with the NVS group. In addition, the MOAS score was positively correlated with the duration, occurrence, and coverage of microstate A. The present study found an abnormal pattern of EEG microstates in violent patients with schizophrenia, which might help clinicians identify patients with schizophrenia who might engaged in violence as well as develop intervention strategies at an early stage.

Theory of Mind in Offending: A Systematic Review

Theory of mind (ToM) impairment is associated with poor social functioning in some psychological disorders (e.g., autism and schizophrenia). ToM deficits have also been linked with offending behavior in the theoretical literature. However, no review has examined the empirical evidence for such a link. We carried out a systematic review to provide a critical overview of studies involving ToM ability in offenders. We included studies published in English that used an instrument to measure at least one aspect of ToM. Twenty-eight eligible studies were identified and coded. Our findings reveal a generally mixed literature. Taking study quality into account, our findings suggest that offenders and nonoffenders do not differ in their first-order ToM. For second-order ToM, findings are mixed, even when only the highest quality studies are examined. Studies exploring advanced ToM showed mixed results overall, though the highest quality research appeared to indicate that offenders have impairments in advanced ToM which means that they may have difficulty understanding various mental states such as pretense, white lies, irony, double bluffs, and sarcasm. We suggest that well-controlled future studies, which also measure other facets of ToM (e.g., distinguishing between cognitive and affective ToM or examining ToM content), are needed to fully understand the role of ToM in offending.

Personal insult disrupts regulatory brain networks in violent offenders

The failure to adequately regulate negative emotions represents a prominent characteristic of violent offenders. In this functional magnetic resonance imaging study, we used technical, nonsocial frustration to elicit anger in violent offenders (n = 19) and then increased the provocation by adding personal insults (social provocation). The aim was to investigate neural connectivity patterns involved in anger processing, to detect the effect of increasing provocation by personal insult, and to compare anger-related connectivity patterns between offenders and noncriminal controls (n = 12). During technical frustration, the offenders showed increased neural connectivity between the amygdala and prefrontal cortex compared to the controls. Conversely, personal insults, and thus increased levels of provocation, resulted in a significant reduction of neural connectivity between regions involved in cognitive control in the offenders but not controls. We conclude that, when (nonsocially) frustrated, offenders were able to employ regulatory brain networks by displaying stronger connectivity between regulatory prefrontal and limbic regions than noncriminal controls. In addition, offenders seemed particularly sensitive to personal insults, which led to increased implicit aggression (by means of motoric responses) and reduced connectivity in networks involved in cognitive control (including dorsomedial prefrontal cortex, precuneus, middle/superior temporal regions).

Reading language of the eyes

The need for assessment of social skills in clinical and neurotypical populations has led to the widespread, and still increasing use of the 'Reading the Mind in the Eyes Test' (RMET) developed more than two decades ago by Simon Baron-Cohen and colleagues for evaluation of social cognition in autism. By analyzing most recent clinical and brain imaging data, we illuminate a set of factors decisive for using the RMET. Converging evidence indicates: (i) In neurotypical individuals, RMET scores are tightly correlated with other social skills (empathy, emotional intelligence, and body language reading); (ii) The RMET assesses recognition of facial affect, but also heavily relies on receptive language skills, semantic knowledge, and memory; (iii) RMET performance is underwritten by the large-scale ensembles of neural networks well-outside the social brain; (iv) The RMET is limited in its capacity to differentiate between neuropsychiatric conditions as well as between stages and severity of a single disorder, though it reliably distinguishes individuals with altered social cognition or elevated pathological traits from neurotypical persons; (v) Merely gender (as a social construct) rather than neurobiological sex influences performance on the RMET; (vi) RMET scores do not substantially decline in healthy aging, and they are higher with higher education level, cognitive abilities, literacy, and mental well-being; (vii) Accuracy on the RMET, and engagement of the social brain, are greater when emotions are expressed and recognized by individuals with similar cultural/ethnic background. Further research is required to better inform usage of the RMET as a tool for swift and reliable examination of social cognition. In light of comparable visual input from the RMET images and faces covered by masks due to COVID-19 regulations, the analysis is of value for keeping efficient social interaction during the current pandemic, in particular, in professional settings related to social communication.

Can we rewire criminal mind via non-invasive brain stimulation of prefrontal cortex? Insights from clinical, forensic and social cognition studies

Non-compliance with social and legal norms and regulations represents a high burden for society. Social cognition deficits are frequently called into question to explain criminal violence and rule violations in individuals diagnosed with antisocial personality disorder (APD), borderline personality disorder (BPD), and psychopathy. In this article, we proposed to consider the potential benefits of non-invasive brain stimulation (NIBS) to rehabilitate forensic population. We focused on the effects of NIBS of the prefrontal cortex, which is central in social cognition, in modulating aggression and impulsivity in clinical disorders, as well as in forensic population. We also addressed the effect of NIBS on empathy, and theory of mind in non-clinical and/or prison population. The reviewed data provide promising evidence on the beneficial effect of NIBS on aggression/impulsivity dyscontrol and social cognitive functions, suggesting its relevance in promoting reintegration of criminals into society.

THE IMPLICATIONS OF FRONTOTEMPORAL DEMENTIA FOR BRAIN DYSFUNCTION IN PSYCHOPATHY

Understanding how psychopathy compares with brain disease can help clarify its underlying mechanisms. This literature review is a broad overview of the neurobiology of psychopathic traits in comparison to behavioral variant frontotemporal dementia (bvFTD), a disorder uniquely associated with criminal behavior. In addition to violation of social norms, both psychopathy and bvFTD result in impaired socioemotional perception and empathy, impulsivity, and altered moral judgment. Despite wide areas of decreased function in psychopathy, structural changes are primarily evident in amygdala and, to a lesser extent, anterior insula, whereas in bvFTD neuropathology involves a wider paralimbic region. In psychopathy, relatively intact medial prefrontal and anterior cingulate cortices facilitate theory of mind and psychopathic traits such as deceitfulness and manipulation, bold fearlessness, and risk-taking behavior. In conclusion, many frontotemporal areas are hypoactive in psychopathy and bvFTD, but differences in dysfunctional connectivity in psychopathy vs. direct involvement in bvFTD potentially explain similarities and differences between these two conditions.

Mistakes in interpersonal perceptions: Social cognition in aggressive forensic psychiatry patients

BACKGROUND

While there is an established link between untreated psychosis and aggression, an enhanced understanding of the role of social cognition is still needed.

AIMS

To examine social cognitive functioning among patients in a specialist forensic mental health service who had been deemed not criminally responsible for acts of violence due to a psychotic disorder. It was hypothesised, first, that such patients would show reduced social cognitive functioning compared with healthy, nonviolent comparison participants and, second, that those who continued to be aggressive while inpatients would demonstrate significant reductions compared to the now nonaggressive group.

METHODS

The study samples were of 10 recently aggressive and 15 not-recently aggressive patients and 20 healthy, nonviolent comparison participants. Each completed the Toronto Empathy Questionnaire (TEQ), the Reading the Mind in the Eyes Test-Revised (RMET) and the Interpersonal Perception Task-15 (IPT-15).

RESULTS

There was no significance between group differences on the RMET and TEQ. The patient group as a whole, however, showed significant interpersonal misperceptions, with specific misperceptions on IPT-15 deception and kinship subscales, while at the same time lacking self-awareness of their errors. Misperceptions on the IPT-15 competition subscale were unique to recently aggressive patients.

CONCLUSIONS

Select aspects of reduced social cognitive functioning were found among not criminally responsible patients with psychosis who had committed violent acts and who continued to act aggressively while forensic inpatients. These findings enhance our understanding of the role of social cognition in predisposing toward violence and the potential importance of incorporating interventions which improve social cognition directly. We suggest also the potential for future research using virtual reality technologies in treatment.

Reading and reacting to faces, the effect of facial mimicry in improving facial emotion recognition in individuals with antisocial behavior and psychopathic traits

Individuals with antisocial behavior and psychopathic traits are characterized by deficits in processing facial expressions, which results in poor social adaptation and dysfunctional interpersonal relationships. However, it is not clear how individuals with varying levels of these traits differ in this emotional impairment and if these deficits are due to correctly identifying or reacting appropriately to facial expressions. The aim of the study was to examine how individuals with these traits recognized and responded to affective facial expressions by using FaceReader software (which analyses footage of faces) across different experimental conditions (imitation, suppression, and control). Imitating facial expressions was introduced to examine whether it could direct participants’ attention to the facial cues and improve participants’ performance on the facial task. A total of 643 individuals from the community were pre-screened and a sample (N = 107; M age = 21.08, SD = 1.55), differentiated on levels of antisocial personality disorder (APD) symptoms and psychopathic (PSY) traits, who were selected based on extreme scores (high/low), were invited to participate in the study. Individuals with higher levels of APD symptoms and PSY traits (APD + PSY) expressed more anger than other groups, while those in the APD-only group expressed more sadness, compared to other groups. Overall, participants were compliant in following the instructions to imitate facial expressions. However, only the group with predominantly APD symptoms and the group with combined symptoms (APD + PSY) showed improvement in their accuracy ratings specifically when instructed to imitate facial expressions, compared to when no instructions were provided. The study offers a promising direction for targeting deficits in facial emotion recognition, suggesting that the deficits found in individuals with behavioral problems (with and without psychopathic traits) can be improved by asking them to imitate facial expressions.

Could Expanding and Investing in First-Episode Psychosis Services Prevent Aggressive Behaviour and Violent Crime?

OBJECTIVE

Some persons developing, or presenting, schizophrenia engage in aggressive behaviour (AB) and/or criminal offending. Most of these individuals display AB prior to a first episode of psychosis (FEP). In fact, approximately one-third of FEP patients have a history of AB, some additionally display other antisocial behaviours (A+AB). The large majority of these individuals have presented conduct problems since childhood, benefit from clozapine, have extensive treatment needs, and are unlikely to comply with treatment. A smaller sub-group begin to engage in AB as illness onsets. A+AB persists, often for many years in spite of treatment-as-usual, until a victim is seriously harmed. This article proposes providing multi-component treatment programs at FEP in order to prevent aggressive and antisocial behaviours of persons with schizophrenia.

METHOD

Non-systematic reviews of epidemiological studies of AB among persons with schizophrenia, of the defining characteristics of sub-types of persons with schizophrenia who engage in AB and their responses to treatment, and of FEP service outcomes.

RESULTS

Studies have shown that mental health services that simultaneously target schizophrenia and aggressive behaviour are most effective both in reducing psychotic symptoms and aggressive behaviour. Evidence, although not abundant, suggests that a multi-component treatment program that would include the components recommended to treat schizophrenia and cognitive-behavioural interventions to reduce A+AB, and the other factors promoting A+AB such as substance misuse, victimisation, and poor recognition of emotions in the faces of others has the potential to effectively treat schizophrenia and reduce A+AB. Patients with a recent onset of AB would require few components of treatment, while those with prior conduct disorder would require all. Such a program of treatment would be long and intense.

CONCLUSIONS

Trials are needed to test the effectiveness of multi-component treatment programs targeting schizophrenia and A+AB at FEP. Studies are also necessary to determine whether providing such programs in hospitals and/or prisons, with long-term community after-care, and in some cases with court orders to participate in treatment, would enhance effectiveness. Whether investing at FEP would be cost-effective requires investigation.

Neural processing associated with Cognitive Empathy in Pedophilia and Child Sexual Offending

Behavioral studies found evidence for superior cognitive empathy (CE) in pedophilic men without a history of child sexual offending (P-CSO) compared to pedophilic men with a history of CSO (P+CSO). Functional magnetic resonance imaging (fMRI) studies also point to differences between P-CSO and P+CSO. Neural processing associated with CE has not yet been investigated. Therefore, the present study aimed to explore the neural correlates of CE in subjects with pedophilia with (P+CSO) and without (P-CSO) child sexual offending. 15 P+CSO, 15 P-CSO, and 24 teleiophilic male controls (TC) performed a CE task during fMRI. We observed reduced activation in the left precuneus (Pcu) and increased activation in the left anterior cingulate cortex (ACC) in P-CSO compared to P+CSO. P-CSO also showed stronger connectivity between these regions, which might reflect a top-down modulation of the Pcu by the ACC toward an increased self-focused emotional reaction in social situations. There was also evidence for increased right superior temporal gyrus activation in P-CSO that might constitute a potentially compensatory recruitment due to the dampened Pcu activation. These findings provide first evidence for altered neural processing of CE in P-CSO and underline the importance of addressing CE in pedophilia and CSO in order to uncover processes relevant to effective prevention of child sexual abuse.

Measures of empathy in children and adolescents: A systematic review of questionnaires

BACKGROUND

Empathy has long been considered a multidimensional construct, encompassing cognitive, affective and behavioral domains. Deficits in empathic competences in early childhood contribute to psychopathology, and have been variably implicated in several clinical conditions, such as autism spectrum disorders (ASD) and conduct disorders.

AIM

To identify and describe empirically validated questionnaires assessing empathy in children and adolescents and to provide a summary of related theoretical perspectives on empathy definitional issues.

METHODS

A systematic review of the literature was conducted. Three bibliographic databases were searched. A total of 47 studies were selected for final analysis and 16 distinct measures were identified and described.

RESULTS

Questionable to excellent levels of internal consistency were observed, while few studies assessed test-retest reliability. Although construct definitions only partially overlapped, affective and cognitive domains of empathy were the commonest internal factors that were often separately evaluated. New facets of the construct (i.e., somatic empathy and sympathy) and specific clinical populations (i.e., ASD) could be specifically addressed through more recent instruments.

CONCLUSION

The combination of different assessment methods is recommended in order to foresee further improvements in this field and try to overcome the problem of limited convergence with more objective measures.

Impaired Perception of Unintentional Transgression of Social Norms after Prefrontal Cortex Damage: Relationship to Decision Making, Emotion Recognition, and Executive Functions

OBJECTIVE

Patients with prefrontal cortex damage often transgress social rules and show lower accuracy in identifying and explaining inappropriate social behavior. The objective of this study was to examine the relationship between the ability to perceive other unintentional transgressions of social norms and both decision making and emotion recognition as these abilities are critical for appropriate social behavior.

METHOD

We examined a group of patients with focal prefrontal cortex damage (N = 28) and a group of matched control participants (N = 28) for their abilities to detect unintentional transgression of social norms using the "Faux-Pas" task of theory of mind, to make advantageous decisions on the Iowa gambling task, and to recognize basic emotions on the Ekman facial affect test.

RESULTS

The group of patients with frontal lobe damage was impaired in all of these tasks compared with control participants. Moreover, all the "Faux-Pas", Iowa gambling, and emotion recognition tasks were significantly associated and predicted by executive measures of inhibition, flexibility, or planning. However, only measures from the Iowa gambling task were associated and predicted performance on the "Faux-Pas" task. These tasks were not associated with performance in recognition of basic emotions. These findings suggest that theory of mind, executive functions, and decision-making abilities act in an interdependent way for appropriate social behavior. However, theory of mind and emotion recognition seem to have distinct but additive effects upon social behavior. Results from VLSM analysis also corroborate these data by showing a partially overlapped prefrontal circuitry underlying these cognitive domains.

Neuroscience, Empathy, and Violent Crime in an Incarcerated Population: A Narrative Review

Empathy is a fundamental construct that allows individuals to perceive and understand the cognitive and emotional state of others. Empathy is not only a psychological and sociological concept; it also heavily impacts our daily lives by affecting our decisions and actions. Empathy is connected to and involves specific parts of the brain which, if damaged or of reduced volume, can lead to actions that are morally unjust, aggressive, or simply denoting a lack of understanding and sensitivity. The literature affirms that the low level of empathy, guilt, embarrassment, and moral reasoning displayed by violent and psychopathic criminals is strongly associated with empathy-linked brain regions that are smaller in size or less developed. The aim of this review is to show empirical data over the last 5 years on the connection between empathy and neuroscience among violent and psychopathic offenders, reflecting on future research on the topic.

A Systematic Review of the Current Measures of Theory of Mind in Adults with Schizophrenia

Adults with schizophrenia usually have impairments in theory of mind (ToM), which subsequently cause them problems in social interaction. Therefore, it is important for healthcare providers to assess their ToM using adequate measures. This systematic review evaluated current ToM measures (or ToM tasks) for adults with schizophrenia and summarized their specific characteristics, including the concept and construct, administration, and psychometric properties. From a review of 117 articles, 13 types of ToM tasks were identified, and the findings from these articles were qualitatively synthesized. The results showed that ToM tasks are diverse in their presentation modalities, answer modes, strategies of controlling cognitive confounders, and scoring. Most tasks employ cognitive and affective dimensions and target a specific, single ToM concept. The present systematic review found that psychometric evidence supporting the ToM tasks, such as internal consistency, test–retest reliability, unidimensionality, and convergent, criterion, and ecological validities, is insufficient. Based on the results, we propose several principles for selecting appropriate ToM tasks in practice, e.g., selecting a task with multiple ToM concepts, or an exclusive ToM construct containing the cognitive and affective dimensions. Moreover, future studies are needed to provide more psychometric evidence on each type of ToM task applied in people with schizophrenia.

Individuals with schizophrenia who act violently towards others profit unequally from inpatient treatment-Identifying subgroups by latent class analysis

BACKGROUND

People with schizophrenia show a higher risk of committing violent offenses. Previous studies indicate that there are at least three subtypes of offenders with schizophrenia.

OBJECTIVES

Employing latent class analysis, the goals of this study were to investigate the presence of homogeneous subgroups of offender patients in terms of remission in psychopathology during inpatient treatment and whether or not these are related to subtypes found in previous studies. Results should help identify patient subgroups benefitting insufficiently from forensic inpatient treatment and allow hypotheses on possibly more suitable therapy option for these patients.

METHODS

A series of latent class analyses was used to explore extensive and detailed psychopathological reports of 370 offender patients with schizophrenia before and after inpatient treatment.

RESULTS

A framework developed by Hodgins to identify subgroups of offenders suffering from schizophrenia is useful in predicting remission of psychopathology over psychiatric inpatient treatment. While "early starters" were most likely to experience remission of psychopathology over treatment, "late late starters" and a subgroup including patients from all three of Hodgins' subgroups in equal proportions benefited least. Negative symptoms generally seemed least likely to remit.

CONCLUSION

Psychiatric treatment may have to be more tailored to offender patient subgroups to allow them to benefit more equally.

The Importance of Conduct Disorder in the Treatment of Violence in Schizophrenia: Efficacy of Clozapine Compared With Olanzapine and Haloperidol

OBJECTIVE

Treatment of violence in schizophrenia remains a challenging problem, especially in patients with conduct disorder. Previous clinical studies did not select patients on the basis of violence and did not focus on conduct disorder. This study is a head-to-head comparison of clozapine, olanzapine, and haloperidol in the treatment of violent schizophrenia patients with and without conduct disorder.

METHODS

Physically assaultive schizophrenia patients (N=99) were randomly assigned to receive clozapine, olanzapine, or haloperidol in a 12-week double-blind trial. They were characterized on the basis of the presence or absence of conduct disorder before age 15. Assaults were recorded; their frequency and severity were scored on the Modified Overt Aggression Scale. Psychiatric symptoms were evaluated through the Positive and Negative Syndrome Scale.

RESULTS

Patients with a history of conduct disorder had more frequent and severe assaults than those without conduct disorder during the 12-week trial. Clozapine was superior to haloperidol and olanzapine in reducing assaults; olanzapine was superior to haloperidol. Clozapine's greater antiaggressive efficacy over haloperidol was substantially more pronounced in patients with conduct disorder than in patients without conduct disorder. In patients with conduct disorder, clozapine was four times more likely than haloperidol to result in lower violence; in patients without conduct disorder, it was three times more likely to do so. Olanzapine's superiority over haloperidol was also more pronounced in patients with conduct disorder.

CONCLUSIONS

This study is the first to examine the effect of clozapine in violent schizophrenia patients with conduct disorder. When conduct disorder is present, clozapine is the optimal treatment.

Schizotypy and psychopathic tendencies interactively improve misattribution of affect in boys with conduct problems

Psychopathic tendencies are associated with difficulties in affective theory of mind (ToM), that is, in recognizing others affective mental states. In clinical and non-clinical adult samples, it has been shown that where psychopathic tendencies co-occur with schizophrenia spectrum disorders, the impairing effects of psychopathic tendencies on ToM are attenuated. These effects are yet to be examined in adolescents. We examined if the impairing effect of psychopathic tendencies on affective ToM was attenuated with increasing severity of schizotypal personality disorder (PD) in a sample of 80 incarcerated adolescent boys. We showed that the impairing effect of psychopathic tendencies on the recognition of neutral mental states, but not positive or negative mental states, was evident when the relative severity of schizotypal PD was low. However, with higher scores on both measures, we observed better performance in judging neutral mental states. The preservation of affective ToM in adolescents who show elevations in psychopathic tendencies and schizotypal PD may enable them to manipulate and extort their victims for personal gain. Our results emphasize the need to consider comorbidity in clinical case formulation when working with adolescents with conduct problems and psychopathic tendencies. More broadly, our results also suggest that the pattern of social cognitive abilities associated with co-occurring psychopathology does not always conform to an often-theorized double-dose of deficit hypothesis.

Neurofunctional abnormalities in antisocial spectrum: A meta-analysis of fMRI studies on Five distinct neurocognitive research domains

Past functional magnetic resonance imaging on antisocial subjects have shown important inconsistencies and methodological problems (e.g. heterogeneity in fMRI tasks domain, small sample sizes, analyses on regions-of-interest). We aimed to conduct a meta-analysis of whole-brain fMRI studies on antisocial individuals based on distinct neurocognitive domains. A voxel-based meta-analysis via permutation of subject images (SDM-PSI) was performed on studies using fMRI tasks in the domains of acute threat response, cognitive control, social cognition, punishment and reward processing. Overall, 83 studies were retrieved. Using a liberal statistical threshold, several key regions were identified in the meta-analysis, principally during acute threat response, social cognition and cognitive control tasks. Additionally, we observed that the right amygdala was negatively associated with both callous-unemotional traits and severity of antisocial behaviors, in meta-analyses on region-of-interest and on dimensional studies, respectively. The findings show that the most prominent functional brain deficits arise during acute threat response, social cognitions and cognitive control neurocognitive domains. These results provide substantial insights for our understanding of aberrant neural processing across specific contexts.

Inferior frontal gyrus gray matter volume is associated with aggressive behavior in schizophrenia spectrum disorders

We aimed to assess potential gray matter (GM) alterations for aggressive patterns of behavior in a sample of in- and outpatients with schizophrenia spectrum disorders. Eighty-four patients previously participating in brain volumetric studies were included. Aggression was assessed using the Modified Overt Aggression Scales (MOAS) based upon review of clinical records of the hospital register. Multiple regression analyses for total MOAS and each MOAS subscale separately were conducted correcting for age, sex, history of addiction, chlorpromazine equivalents, illness duration, and total intracranial volume. Significant effects were reported in two cases; the total MOAS scores and MOAS verbal aggression scores were associated with GM volume in left inferior frontal gyrus. From the demographic/clinical characteristics, only the number of episodes correlated with the subscales and the total MOAS scores. Our results highlight the role of GM volume in left inferior frontal gyri in patients with history of aggression. This evidence ties in well with previous data reporting involvement of these regions in response control and semantic networks.

What Do You Have in Mind? Measures to Assess Mental State Reasoning in Neuropsychiatric Populations

Social interaction is closely associated with both functional capacity and well-being. Previous research has not only revealed evidence of social dysfunction in individuals with a wide range of psychiatric and neurological disorders but also generated an abundance of potential measures for assessing social cognition. This review explores the most popular measures used within neuropsychiatric populations to investigate the ability to recognize or reason about the mental states of others. Measures are also critically analyzed in terms of strengths and limitations to aid task selection in future clinical studies. The most frequently applied assessment tools use verbal, visual or audiovisual forms of presentation and assess recognition of mental states from facial features, self-rated empathy, the understanding of other's cognitive mental states such as beliefs and intentions, or the ability to combine knowledge of other's thoughts and emotions in order to understand subtle communications or socially inappropriate behavior. Key weaknesses of previous research include limited investigation of relationships with clinical symptoms, and underutilization of measures of everyday social functioning that offer a useful counterpart to traditional "lab" tasks. Future studies should aim to carefully select measures not only based on the range of skills to be assessed but also taking into account potential difficulties with interpretation and the need to gain insight into the application of social cognitive skills as well as ability per se. Some of the best measures include those with well-matched control trials (e.g., Yoni Task) or those that restrict the influence of verbal deficits (e.g., intentions comic strip task), elicit spontaneous mentalizing (e.g., Animations Task), and possess greater ecological validity (e.g., Movie for the Assessment of Social Cognition). Social cognitive research within psychiatric populations will be further enhanced through the development of more closely matched control tasks, and the exploration of relationships between task performance, medication, strategy use, and broader emotional and motor functions.

The NIMH Research Domain Criteria (RDoC) Initiative and Its Implications for Research on Personality Disorder

PURPOSE OF REVIEW

We discuss the implications of the Research Domain Criteria (RDoC) initiative for neuroscience research on personality disorder (PD). To organize our review, we construct a preliminary conceptual mapping of PD symptom criteria onto RDoC constructs. We then highlight recent neuroscience research, often built around concepts that correspond to RDoC elements, and discuss the findings in reference to the constructs we consider most pertinent to PD.

RECENT FINDINGS

PD symptoms were strongly conceptually tied to RDoC constructs within the Social Processes domain, implicating brain systems involved in interpersonal rejection, facial emotion perception, and self-referential processes. Negative and Positive Valence Systems were conceptually associated with many PD symptoms, with particular relevance ascribed to the latter's Reward Valuation construct, which could reflect a more widespread disruption of computational processes involved in estimating the probability and benefits of a future outcome. Within the Cognitive Systems domain, the Cognitive Control construct mainly related to PD symptoms associated with impulse control, suggesting a connection to neural circuits that underlie goal selection and behavioral control. Arousal and Regulatory Systems could only be conceptually mapped onto PD symptoms through the Arousal construct, with different symptoms reflecting either a higher or lower biological sensitivity to internal and external stimuli. The RDoC framework has promise to advance neuroscience research on PD. The Social Processes domain is especially relevant to PD, although constructs falling within the other RDoC domains could also yield important insights into the neurobiology of PD and its connections with other forms of psychopathology. Identifying RDoC constructs (e.g., habit formation) that subserve more fundamental processes relevant to personality functioning warrants further investigation.

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.

Neural networks of aggression: ALE meta-analyses on trait and elicited aggression

There is considerable evidence that emotion dysregulation and self-control impairments lead to escalated aggression in populations with psychiatric disorders. However, convergent quantitative evidence on the neural network explaining how aggression arises is still lacking. To address this gap, peak activations extracted from extant functional magnetic resonance imaging (fMRI) studies were synthesized through coordinate-based meta-analyses. A systematic search in the PubMed database was conducted and 26 fMRI studies met the inclusion criteria. Three separate activation likelihood estimation (ALE) meta-analyses were performed on (1) individual differences in trait aggression (TA) studies, (2) individual differences in TA studies examining executive functioning, and (3) elicited aggression (EA) studies across fMRI behavioral paradigms. Ensuing clusters from ALE meta-analyses were further treated as seeds for follow-up investigations on consensus connectivity networks (CCN) delineated from meta-analytic connectivity modeling (MACM) and resting-state functional connectivity (RSFC) to further characterize their physiological functions. Finally, we obtained a data-driven functional characterization of the ensuing clusters and their networks. This approach offers a boarder view of the ensuing clusters using a boarder network perspective. In TA, aberrant brain activations were found only in the right precuneus. Follow-up analyses revealed that the precuneus seed was within the frontal-parietal network (FPN) associated with action inhibition, visuospatial processing and higher-level cognition. With further restricting to only experiments examining executive functioning, convergent evidence was found in the right rolandic operculum (RO), midcingulate cortex (MCC), precentral gyrus (PrG) and precuneus. Follow-up analyses suggested that RO, MCC and PrG may belong to a common cognitive control network, while the MCC seems to be the hub of this network. In EA, we only revealed a convergent region in the left postcentral gyrus. Follow-up CCN analyses and functional characterizations suggested that this region may also belong to the same cognitive control network found in the TA sub-analysis. Our results suggested that escalated aggression arises from abnormal precuneus activities within the FPN, disrupting the recruitment of other large-scale networks such as adaptive cognitive control network. Consequently, failure to recruit such a network results in an inability to generate adaptive responses, increasing the likelihood of acting aggressively.

Functional Neuroimaging Correlates of Aggression in Psychosis: A Systematic Review With Recommendations for Future Research

Background and methods: Aggression in psychosis is clinically important. We systematically compiled the evidence on functional correlates of aggression in psychosis searching PubMed, EMBASE, ScienceDirect, and PsycINFO until September 2017. We included studies reporting functional brain imaging correlates of aggression comparing: (1) affective or non-affective psychosis groups with a history of violence or with aggression operationalized using questionnaires, (2) affective or non-affective psychosis groups with a history of violence or with aggression operationalized using questionnaires to controls, (3) affective or non-affective psychosis groups with a history of violence or with aggression operationalized using questionnaires to controls with diagnoses other than affective or non-affective psychoses. We applied no language restriction and required patients to have a DSM or ICD diagnosis of affective or non-affective psychosis. Results: Our sample consisted of 12 studies with 334 patients and 113 controls. During n-back tasks, violent (VS) as opposed to non-violent persons with schizophrenia (NVS) hypoactivated their inferior parietal lobe. When anticipating shock, VS vs. NVS hyperactivated their medial prefrontal gyrus, cuneus, middle temporal gyrus, and middle occipital gyrus. When viewing negative emotional pictures, VS vs. NVS hyperactivated the middle frontal gyrus, inferior frontal gyrus, anterior cingulate, lingual gyrus, precentral gyrus, globus pallidus, mid-cingulate, and precuneus. Limitations: Due to the small number of available studies, sample overlap, and insufficient reporting of relevant moderators we could not conduct a meta-analysis. Conclusions: We found non-systematic functional correlates of aggression in schizophrenia. Only few studies using varied paradigms and often overlapping samples have been conducted. There have been no attempts to replicate any of the observed findings in the published literature. Focusing on future directions, we recommend that authors adhere to clear definitions of aggression, measurements of psychopathology, comorbidities, and medication. In particular, replication studies would allow for a better synthesis of the findings. PROSPERO Registration Number: CRD42016048579.

The role of central and medial amygdala in normal and abnormal aggression: A review of classical approaches

The involvement of the amygdala in aggression is supported by overwhelming evidence. Frequently, however, the amygdala is studied as a whole, despite its complex internal organization. To reveal the role of various subdivisions, here we review the involvement of the central and medial amygdala in male rivalry aggression, maternal aggression, predatory aggression, and models of abnormal aggression where violent behavior is associated with increased or decreased arousal. We conclude that: (1) rivalry aggression is controlled by the medial amygdala; (2) predatory aggression is controlled by the central amygdala; (3) hypoarousal-associated violent aggression recruits both nuclei, (4) a specific upregulation of the medial amygdala was observed in hyperarousal-driven aggression. These patterns of amygdala activation were used to build four alternative models of the aggression circuitry, each being specific to particular forms of aggression. The separate study of the roles of amygdala subdivisions may not only improve our understanding of aggressive behavior, but also the differential control of aggression and violent behaviors of various types, including those associated with various psychopathologies.

Neurobiology of Criterion A: self and interpersonal personality functioning

The Criterion A of the DSM-5 Alternative Model of Personality Disorders follows a functional approach to personality disorders which can be effectively related to abnormalities in brain circuits that are involved in processes related to the self and others. While brain circuits related to the self and others highly overlap supporting the notion of inseparable constructs, structural and functional neuroimaging data point to rather specific deviations in brain processes among the various types of personality disorders, with a focus on borderline and antisocial personality disorders. Neurobiological data have shed light on the problem areas of individuals with personality disorders that goes beyond what we know from either patients' reports or observing their behavior and may open new perspectives on treatment.

Aggressive Behavior Among Persons With Schizophrenia and Those Who Are Developing Schizophrenia: Attempting to Understand the Limited Evidence on Causality

People with, and those who are developing, schizophrenia are at increased risk to engage in aggressive behavior (AGB). Some incidents lead to criminal prosecution. Most people with schizophrenia who commit crimes engage in delinquency and/or AGB prior to first episode. A large proportion of these individuals have a history of childhood conduct disorder (CD) and brain abnormalities suggestive of abnormal neural development distinctive from that of others with schizophrenia. Factors contributing to schizophrenia that is preceded by CD include failing to learn not-to-behave aggressively in early childhood, impairments in understanding emotions in the faces of others, maltreatment, and subsequent re-victimization. Others with no history of antisocial behavior begin engaging in AGB as positive symptoms increase and illness onsets. They too are at elevated risk to be victimized. Specific genetic variants linked to stress regulation in combination with adversity have been associated both with AGB and psychotic symptoms. Effectively treating conduct problems and preventing victimization would reduce AGB by persons with schizophrenia.

Autistic traits and positive psychotic experiences modulate the association of psychopathic tendencies with theory of mind in opposite directions

Various clinical disorders, including psychopathy, and autism and schizophrenia spectrum disorders, have been linked with impairments in Theory of Mind (ToM). However, although these conditions can co-occur in the same individual, the effect of their inter-play on ToM abilities has not been investigated. Here we assessed ToM abilities in 55 healthy adults while performing a naturalistic ToM task, requiring participants to watch a short film and judge the actors' mental states. The results reveal for the first time that autistic traits and positive psychotic experiences interact with psychopathic tendencies in opposite directions to predict ToM performance-the interaction of psychopathic tendencies with autism traits was associated with a decrement in performance, whereas the interaction of psychopathic tendencies and positive psychotic experiences was associated with improved performance. These effects were specific to cognitive rather than affective ToM. These results underscore the importance of the simultaneous assessment of these dimensions within clinical settings. Future research in these clinical populations may benefit by taking into account such individual differences.