Reduced P300 responses in criminal psychopaths during a visual oddball task

EEG study on implicit beliefs regarding sexuality: Psychophysiological measures in relation to self-report measures

In this exploratory, correlational study, several psychophysiological measures were assessed and the relation between these measures and an experimental self-report questionnaire to measure the seven implicit beliefs of sexual offenders (the Questionnaire for Implicit Theories of Sexual Offenders (QITSO)) was established in a sample of Dutch participants recruited from the healthy population (N = 28) using correlational analyses. After analyzing task performance, electroencephalogram (EEG) data and electrocardiogram (ECG) data, the psychophysiological variables were correlated with the experimental QITSO subscales. The subscale “children as sexual beings” correlated positively with the P300 amplitude at electrode Pz. The subscale “women are unknowable” correlated positively with resting-state beta activity during eyes closed and eyes open, and with alpha activity during eyes open. Additionally, the subscale “entitlement’ correlated positively with low frequency heart rate variability power during eyes closed and eyes open, and with high frequency power during eyes closed. This study is a first exploratory step towards establishing a psychophysiological profile underlying the self-report questionnaire QITSO.

Phonological processing in psychopathic offenders

Recent research has demonstrated that psychopathic offenders exhibit dynamic cognitive and behavioral deficits on a variety of lab tasks that differentially activate left hemisphere resources. The Left Hemisphere Activation (LHA) hypothesis is a cognitive perspective that aims to address these deficits by conceptualizing psychopathy as a disorder in which behavior and cognitive processing change dynamically as a function of the differential taxation of left hemisphere resources. This study aimed to investigate whether psychopathic traits are associated with electrophysiological anomalies under conditions that place differential demands on left hemisphere language processing systems. We examined in a sample of 43 incarcerated indivdiuals the evocation of the N320, an event-related potential (ERP) elicited by nontarget stimuli during a phonological/phonetic decision task that has been shown to elicit greater activation and cognitive processing within the left hemisphere than the right hemisphere. Findings for a subsample of 18 offenders low in psychopathic traits were generally consistent with previous findings in healthy individuals, suggesting similar electrophysiological activity during phonological processing. However, psychopathic traits impacted the amplitude of the N320. Higher levels of psychopathic traits were associated with reduced left-lateralization in phonological processing as well as enhanced ERP differentiation between pronounceable and nonpronounceable stimuli. These findings provide physiological evidence of a relationship between psychopathic traits and anomalous language processing at the phonological level of word processing.

Source-Informed Segmentation: A Data-Driven Approach for the Temporal Segmentation of EEG

GOAL

Understanding the dynamics of brain function through non-invasive monitoring techniques requires the development of computational methods that can deal with the non-stationary properties of recorded activities. As a solution to this problem, a new data-driven segmentation method for recordings obtained through electroencephalography (EEG) is presented.

METHODS

The proposed method utilizes singular value decomposition (SVD) to identify the time intervals in the EEG recordings during which the spatial distribution of clusters of active cortical neurons remains quasi-stationary. Theoretical analysis shows that the spatial locality features of these clusters can be, asymptotically, captured by the most significant left singular subspace of the EEG data. A reference/sliding window approach is employed to dynamically extract this feature subspace, and the running projection error is monitored for significant changes using Kolmogorov-Smirnov test.

RESULTS

Simulation results, for a wide range of possible scenarios regarding the spatial distribution of active cortical neurons, show that the algorithm is successful in accurately detecting the segmental structure of the simulated EEG data. The algorithm is also applied to experimental EEG recordings of a modified visual oddball task. Results identify a unique sequence of dynamic patterns in the event-related potential (ERP) response to each of the three involved stimuli.

CONCLUSION

The proposed method, without using source localization methods or scalp topographical maps, is able to identify intervals of quasi-stationarity in the EEG recordings.

SIGNIFICANCE

The proposed segmentation technique can offer new insights on the dynamics of functional organization of the brain in action.

Functional connectivity in incarcerated male adolescents with psychopathic traits

The present study examined the association between psychopathic traits and functional connectivity in 177 incarcerated male adolescents. We hypothesized that psychopathic symptoms would be associated with functional connectivity within networks encompassing limbic and paralimbic regions, such as the default mode (DMN), salience networks (SN), and executive control network (ECN). The present sample was drawn from the Southwest Advanced Neuroimaging Cohort, Youth sample, and from research at a youth detention facility in Wisconsin. All participants were scanned at maximum-security facilities. Psychopathic traits were assessed using Hare's Psychopathy Checklist-Youth Version. Resting-state networks were computed using group Independent Component Analysis. Associations between psychopathic traits and resting-state connectivity were assessed using Mancova analyses. PCL-YV Total score and Factor 1 score (interpersonal and affective traits) were associated with the power spectra of the DMN. Factor 1 score was associated with SN and ECN spatial maps. Factor 2 score (lifestyle and antisocial traits) was associated with spatial map of the ECN. Only the Factor 1 association with DMN power spectrum survived correction for multiple testing. Comparable to adult psychopathy, adolescent psychopathic traits were associated with networks implicated in self-referential thought, moral behavior, cognition, and saliency detection: functions previously reported to be disrupted in adult psychopaths.

Endogenous attention modulates early selective attention in psychopathy: An ERP investigation

Psychopathic individuals are prone to act on urges without adequate consideration of future consequences or the rights of other individuals. One interpretation of this behavior is that it reflects abnormal selective attention (i.e., a failure to process information that is incongruent with their primary focus of attention; Hiatt, Schmitt, & Newman, Neuropsychology, 18, 50-59, 2004). Unfortunately, it is unclear whether this selective attention abnormality reflects top-down endogenous influences, such as the strength or specificity of attention focus (i.e., top-down set) apart from other, more exogenous (bottom-up), effects on attention. To explore this question, we used an early visual event-related potential (N2pc) in combination with a modified visual search task designed to assess the effect of early endogenous (i.e., top-down) attention on the processing of set-congruent information. The task was administered to a sample of 70 incarcerated adult males, who were assigned to high, intermediate, and low psychopathy groups using Hare's Psychopathy Checklist-Revised (Hare, 2003). Based on the assumption that their failure to process set-incongruent information reflects the exaggerated effects of endogenous attention, we predicted that participants with high psychopathy scores would show an exaggerated N2pc response to set-congruent information. The results supported the hypothesis and provide novel electrophysiological evidence that psychopathy is associated with exaggerated endogenous attention effects during early stages of processing. Further research is needed to examine the implications of this finding for the well-established failure of psychopathic individuals to process set-incongruent information and inhibit inappropriate responses.

Brain potentials predict substance abuse treatment completion in a prison sample

INTRODUCTION

National estimates suggest that up to 80% of prison inmates meet diagnostic criteria for a substance use disorder. Because more substance abuse treatment while incarcerated is associated with better post-release outcomes, including a reduced risk of accidental overdose death, the stakes are high in developing novel predictors of substance abuse treatment completion in inmate populations.

METHODS

Using electroencephalography (EEG), this study investigated stimulus-locked ERP components elicited by distractor stimuli in three tasks (VO-Distinct, VO-Repeated, Go/NoGo) as a predictor of treatment discontinuation in a sample of male and female prison inmates. We predicted that those who discontinued treatment early would exhibit a less positive P3a amplitude elicited by distractor stimuli.

RESULTS

Our predictions regarding ERP components were partially supported. Those who discontinued treatment early exhibited a less positive P3a amplitude and a less positive PC4 in the VO-D task. In the VO-R task, however, those who discontinued treatment early exhibited a more negative N200 amplitude rather than the hypothesized less positive P3a amplitude. The discontinuation group also displayed less positive PC4 amplitude. Surprisingly, there were no time-domain or principle component differences among the groups in the Go/NoGo task. Support Vector Machine (SVM) models of the three tasks accurately classified individuals who discontinued treatment with the best model accurately classifying 75% of inmates. PCA techniques were more sensitive in differentiating groups than the classic time-domain windowed approach.

CONCLUSIONS

Our pattern of findings are consistent with the context-updating theory of P300 and may help identify subtypes of ultrahigh-risk substance abusers who need specialized treatment programs.

Delta, theta, and alpha event-related oscillations in alcoholics during Go/NoGo task: Neurocognitive deficits in execution, inhibition, and attention processing

Higher impulsivity observed in alcoholics is thought to be due to neurocognitive functional deficits involving impaired inhibition in several brain regions and/or neuronal circuits. Event-related oscillations (EROs) offer time-frequency measure of brain rhythms during perceptual and cognitive processing, which provide a detailed view of neuroelectric oscillatory responses to external/internal events. The present study examines evoked power (temporally locked to events) of oscillatory brain signals in alcoholics during an equal probability Go/NoGo task, assessing their functional relevance in execution and inhibition of a motor response. The current study hypothesized that increases in the power of slow frequency bands and their topographical distribution is associated with tasks that have increased cognitive demands, such as the execution and inhibition of a motor response. Therefore, it is hypothesized that alcoholics would show lower spectral power in their topographical densities compared to controls. The sample consisted of 20 right-handed abstinent alcoholic males and 20 age and gender-matched healthy controls. Evoked delta (1.0-3.5Hz; 200-600ms), theta (4.0-7.5Hz; 200-400ms), slow alpha (8.0-9.5Hz; 200-300ms), and fast alpha (10.0-12.5Hz; 100-200ms) ERO power were compared across group and task conditions. Compared to controls, alcoholics had higher impulsiveness scores on the Barrett Impulsiveness Scale (BIS-11) and made more errors on Go trials. Alcoholics showed significantly lower evoked delta, theta, and slow alpha power compared to controls for both Go and NoGo task conditions, and lower evoked fast alpha power compared to controls for only the NoGo condition. The results confirm previous findings and are suggestive of neurocognitive deficits while executing and suppressing a motor response. Based on findings in the alpha frequency ranges, it is further suggested that the inhibitory processing impairments in alcoholics may arise from inadequate early attentional processing with respect to the stimulus related aspects/semantic memory processes, which may be reflected in lower posterio-temporal evoked fast alpha power. It can thus be concluded that alcoholics show neurocognitive deficits in both execution and suppression of a motor response and inadequate early attentional processing with respect to the semantic memory/stimulus related aspects while suppressing a motor response.

P300 correlates with learning & memory abilities and fluid intelligence

Background

Educational psychology research has linked fluid intelligence with learning and memory abilities and neuroimaging studies have specifically associated fluid intelligence with event related potentials (ERPs). The objective of this study is to find the relationship of ERPs with learning and memory recall and predict the memory recall score using P300 (P3) component.

Method

A sample of thirty-four healthy subjects between twenty and thirty years of age was selected to perform three tasks: (1) Raven’s Advanced Progressive Matrices (RAPM) test to assess fluid intelligence; (2) learning and memory task to assess learning ability and memory recall; and (3) the visual oddball task to assess brain-evoked potentials. These subjects were divided into High Ability (HA) and Low Ability (LA) groups based on their RAPM scores. A multiple regression analysis was used to predict the learning & memory recall and fluid intelligence using P3 amplitude and latency.

Results

Behavioral results demonstrated that the HA group learned and recalled 10.89 % more information than did the LA group. ERP results clearly showed that the P3 amplitude of the HA group was relatively larger than that observed in the LA group for both the central and parietal regions of the cerebrum; particularly during the 300–400 ms time window. In addition, a shorter latency for the P3 component was observed at Pz site for the HA group compared to the LA group. These findings agree with previous educational psychology and neuroimaging studies which reported an association between ERPs and fluid intelligence as well as learning performance.

Conclusion

These results also suggest that the P3 component is associated with individual differences in learning and memory recall and further indicate that P3 amplitude might be used as a supporting factor in standard psychometric tests to assess an individual’s learning & memory recall ability; particularly in educational institutions to aid in the predictability of academic skills.

Psychopathy, attention, and oddball target detection: New insights from PCL-R facet scores

Psychopathy is a disorder accompanied by cognitive deficits including abnormalities in attention. Prior studies examining cognitive features of psychopaths using ERPs have produced some inconsistent results. We examined psychopathy-related differences in ERPs during an auditory oddball task in a sample of incarcerated adult males. We extend previous work by deriving ERPs with principal component analysis (PCA) and relate these to the four facets of Hare's Psychopathy Checklist Revised (PCL-R). Features of psychopathy were associated with increased target N1 amplitude (facets 1, 4), decreased target P3 amplitude (facet 1), and reduced slow wave amplitude for frequent standard stimuli (facets 1, 3, 4). We conclude that employing PCA and examining PCL-R facets improve sensitivity and help clarify previously reported associations. Furthermore, attenuated slow wave during standards may be a novel marker for psychopaths' abnormalities in attention.

Factors of psychopathy and electrocortical response to emotional pictures: Further evidence for a two-process theory

The Two-Process theory of psychopathy posits that distinct etiological mechanisms contribute to the condition: (a) a weakness in defensive (fear) reactivity related to affective-interpersonal features, and (b) impaired cognitive-executive functioning, marked by reductions in brain responses such as P3, related to impulsive-antisocial features. The current study examined relations between psychopathy factors and electrocortical response to emotional and neutral pictures in male offenders (N = 139) assessed using the Psychopathy Checklist-Revised (PCL-R). Impulsive-antisocial features of the PCL-R (Factor 2) were associated with reduced amplitude of earlier P3 brain response to pictures regardless of valence, whereas the affective-interpersonal dimension (Factor 1) was associated specifically with reductions in late positive potential response to aversive pictures. Findings provide further support for the Two-Process theory and add to a growing body of evidence linking the impulsive-antisocial facet of psychopathy to the broader construct of externalizing proneness. Findings are discussed in terms of current initiatives directed at incorporating neuroscientific concepts into psychopathology classification. (PsycINFO Database Record

Altering the Cognitive-Affective Dysfunctions of Psychopathic and Externalizing Offender Subtypes with Cognitive Remediation

Cognitive remediation is a treatment approach with the potential to translate basic science into more specific, mechanism-based interventions by targeting particular cognitive skills. The present study translated understanding of two well-defined cognitive-emotion dysfunctions into novel deficit-matched interventions and evaluated whether cognitive remediation would demonstrate specific and generalizable change. Two antisocial-subtypes, individuals with psychopathy and externalizing traits, are characterized by cognitive-affective problems that predispose them to engage in significant substance abuse and criminal behavior, culminating in incarceration. Whereas individuals with psychopathy fail to consider important contextual information, individuals with externalizing traits lack the capacity to regulate affective reactions. Training designed to remedy these subtype-specific deficits led to improvement on both trained and non-trained tasks. Such findings offer promise for changing neural and behavioral patterns, even for what many consider to be the most recalcitrant treatment population, and presage a new era of translating cognitive-affective science into increasingly specific and effective interventions.

The posteromedial region of the default mode network shows attenuated task-induced deactivation in psychopathic prisoners

OBJECTIVE

Psychopathy is a personality disorder with symptoms that include lack of empathy or remorse, antisocial behavior, and excessive self-focus. Previous neuroimaging studies have linked psychopathy to dysfunction in the default mode network (DMN), a brain network that deactivates during externally focused tasks and is more engaged during self-referential processing. Specifically, the DMN has been found to remain relatively active in individuals with psychopathic tendencies during externally focused tasks, suggesting a failure to properly deactivate. However, the exact extent and nature of task-induced DMN dysfunction is poorly understood, including (a) the degree to which specific DMN subregions are affected in criminal psychopaths, and (b) how activity in these subregions relates to affective/interpersonal and antisocial/lifestyle traits of psychopathy.

METHOD

We performed a group independent component analysis to assess DMN activation during a Go/NoGo task in a group of 22 high-psychopathy and 22 low-psychopathy prisoners. The identified group-level DMN was parcellated into 6 subregions, and group differences in task-induced activity were examined.

RESULTS

In general, DMN subregions failed to deactivate beneath baseline in the high-psychopathy group. A group comparison with the low-psychopathy group localized this attenuated task-induced deactivation to the posteromedial cortical (mPC) region of the DMN. Moreover, multiple regression analyses revealed that activity in the mPC was associated with affective/interpersonal traits of psychopathy.

CONCLUSION

These findings suggest that attenuated deactivation of the mPC subregion of the DMN is intrinsic to psychopathy, and is a pattern that may be more associated with affective psychopathic traits, including lack of concern for others.

Reconciling discrepant findings for P3 brain response in criminal psychopathy through reference to the concept of externalizing proneness

We sought to address inconsistencies in the literature on amplitude of P3 brain potential response in offenders diagnosed with psychopathy. These inconsistencies contrast with the reliable finding of reduced P3 in relation to externalizing tendencies, which overlap with impulsive-antisocial features of psychopathy, as distinguished from the affective-interpersonal features. Employing a sample of incarcerated male offenders (N = 154) who completed the Psychopathy Checklist-Revised along with a three-stimulus visual oddball task, we tested the hypothesis that impulsive-antisocial features of psychopathy would selectively exhibit an inverse relationship with P3 amplitude. Clear support for this hypothesis was obtained. Our findings clarify the discrepant findings regarding psychopathy and P3, and establish P3 as a neurophysiological point of contact between psychopathy and externalizing proneness from the broader psychopathology literature.

Deficient fear conditioning in psychopathy as a function of interpersonal and affective disturbances

The diminished fear reactivity is one of the most valid physiological findings in psychopathy research. In a fear conditioning paradigm, with faces as conditioned stimulus (CS) and electric shock as unconditioned stimulus (US), we investigated a sample of 14 high psychopathic violent offenders. Event related potentials, skin conductance responses (SCR) as well as subjective ratings of the CSs were collected. This study assessed to which extent the different facets of the psychopathy construct contribute to the fear conditioning deficits observed in psychopaths. Participants with high scores on the affective facet subscale of the Psychopathy Checklist-Revised (PCL-R) showed weaker conditioned fear responses and lower N100 amplitudes compared to low scorers. In contrast, high scorers on the affective facet rated the CS+ (paired) more negatively than low scorers regarding the CS- (unpaired). Regarding the P300, high scores on the interpersonal facet were associated with increased amplitudes to the CS+ compared to the CS-, while the opposed pattern was found for the antisocial facet. Both, the initial and terminal contingent negative variation indicated a divergent pattern: participants with pronounced interpersonal deficits, showed increased cortical negativity to the CS+ compared to the CS-, whereas a reversed CS+/CS- differentiation was found in offenders scoring high on the antisocial facet. The present study revealed that deficient fear conditioning in psychopathy was most pronounced in offenders with high scores on the affective facet. Event related potentials suggest that participants with distinct interpersonal deficits showed increased information processing, whereas the antisocial facet was linked to decreased attention and interest to the CS+. These data indicate that an approach to the facets of psychopathy can help to resolve ambiguous findings in psychopathy research and enables a more precise and useful description of this disorder.

The Southern California Twin Register at the University of Southern California: III

The Southern California Twin Register at the University of Southern California (USC) was initiated in 1984 and continues to provide an important resource for studies investigating genetic and environmental influences on human behavior. This article provides an update on the current register and its potential for future twin studies using recruitment through school district databases and voter records. An overview is also provided for an ongoing longitudinal twin study investigating the development of externalizing psychopathology from childhood to young adulthood, the USC Study of Risk Factors for Antisocial Behavior. Characteristics of the twins and their families are presented, including recruitment and participation rates, as well as attrition analyses and a summary of key findings to date.

Reduced cortical call to arms differentiates psychopathy from antisocial personality disorder

BACKGROUND

Psychopathy and antisocial personality disorder (ASPD) are both characterized by impulsive, externalizing behaviors. Researchers have argued, however, that psychopathy is distinguished from ASPD by the presence of interpersonal-affective features that reflect an underlying deficit in emotional sensitivity. No study to date has tested for differential relations of these disorders with the brain's natural orienting response to sudden aversive events. Method Electroencephalography was used to assess cortical reactivity to abrupt noise probes presented during the viewing of pleasant, neutral and unpleasant pictures in 140 incarcerated males diagnosed using the Psychopathy Checklist - Revised and DSM-IV criteria for ASPD. The primary dependent measure was the P3 event-related potential response to the noise probes.

RESULTS

Psychopaths showed significantly smaller amplitude of P3 response to noise probes across trials of all types compared with non-psychopaths. Follow-up analyses revealed that this overall reduction was attributable specifically to the affective-interpersonal features of psychopathy. By contrast, no group difference in general amplitude of probe P3 was evident for ASPD versus non-ASPD participants.

CONCLUSIONS

The findings demonstrate a reduced cortical orienting response to abrupt aversive stimuli in participants exhibiting features of psychopathy that are distinct from ASPD. The specificity of the observed effect fits with the idea that these distinctive features of psychopathy reflect a deficit in defensive reactivity, or mobilization of the brain's defensive system, in the context of threat cues.

Aberrant paralimbic gray matter in incarcerated male adolescents with psychopathic traits

OBJECTIVE

To investigate the relationship between brain structure and psychopathic traits in maximum-security incarcerated male adolescents, and to examine whether the associations between brain volumes in paralimbic and limbic regions and psychopathic traits observed in incarcerated adult men extend to an independent sample of incarcerated male adolescents.

METHOD

A structural magnetic resonance imaging (MRI) study of regional gray matter volumes by using voxel-based morphometry in maximum-security incarcerated male adolescents (N = 218) assessed for psychopathic traits using the Hare Psychopathy Checklist-Youth Version (PCL-YV). All analyses controlled for effects of age, substance use, and brain size.

RESULTS

Consistent with hypotheses and the adult literature, psychopathic traits were associated with decreased regional gray matter volumes in diffuse paralimbic regions, including orbitofrontal cortex, bilateral temporal poles, and posterior cingulate cortex.

CONCLUSIONS

These results strengthen the interpretation that paralimbic regions are central for understanding neural dysfunction associated with psychopathic traits and that psychopathy is best conceptualized as a neurodevelopmental disorder.

Differentiating psychopathy from general antisociality using the P3 as a psychophysiological correlate of attentional allocation

Recent studies have shown that while psychopathy and non-psychopathic antisociality overlap, they differ in the extent to which cognitive impairments are present. Specifically, psychopathy has been related to abnormal allocation of attention, a function that is traditionally believed to be indexed by event-related potentials (ERPs) of the P3-family. Previous research examining psychophysiological correlates of attention in psychopathic individuals has mainly focused on the parietally distributed P3b component to rare targets. In contrast, very little is known about the frontocentral P3a to infrequent novel events in psychopathy. Thus, findings on the P3 components in psychopathy are inconclusive, while results in non-psychopathic antisocial populations are clearer and point toward an inverse relationship between antisociality and P3 amplitudes. The present study adds to extant literature on the P3a and P3b in psychopathy by investigating component amplitudes in psychopathic offenders (N = 20), matched non-psychopathic offenders (N = 23) and healthy controls (N = 16). Also, it was assessed how well each offender group was able to differentially process rare novel and target events. The offender groups showed general amplitude reductions compared to healthy controls, but did not differ mutually on overall P3a/P3b amplitudes. However, the psychopathic group still exhibited normal neurophysiological differentiation when allocating attention to rare novel and target events, unlike the non-psychopathic sample. The results highlight differences between psychopathic and non-psychopathic offenders regarding the integrity of the neurocognitive processes driving attentional allocation, as well as the usefulness of alternative psychophysiological measures in differentiating psychopathy from general antisociality.

Psychopathy-related differences in selective attention are captured by an early event-related potential

According to the response modulation model, the poorly regulated behavior of psychopathic individuals reflects a problem reallocating attention to process peripheral information while engaged in goal-directed behavior (Patterson & Newman, 1993). We evaluated this tenet using male prisoners and an early event-related potential component (P140) to index attentional processing. In all task conditions, participants viewed and categorized letter stimuli that could also be used to predict electric shocks. Instructions focused attention either on the threat-relevant dimension of the letters or an alternative, threat-irrelevant dimension. Offenders with high scores on Hare's (2003) Psychopathy Checklist-Revised displayed a larger P140 under alternative versus threat conditions. Beyond demonstrating psychopathy-related differences in early attention, these findings suggest that psychopathic individuals find it easier to ignore threat-related distractors when they are peripheral versus central to their goal-directed behavior.

The association between p3 amplitude at age 11 and criminal offending at age 23

Reduced P3 amplitude to targets is an information-processing deficit associated with adult antisocial behavior and may reflect dysfunction of the temporal-parietal junction. This study aims to examine whether this deficit precedes criminal offending. From a birth cohort of 1,795 children, 73 individuals who become criminal offenders at age 23 and 123 noncriminal individuals were assessed on P3 amplitude. The two groups did not differ on gender, ethnicity, and social adversity. P3 amplitude was measured over the temporal-parietal junction during a visual continuous performance task at age 11, together with antisocial behavior. Criminal convictions were assessed at age 23. Reduced P3 amplitude at age 11 was associated with increased antisocial behavior at age 11. Criminal offenders showed significantly reduced P3 amplitudes to target stimuli compared to controls. Findings remained significant after controlling for antisocial behavior and hyperactivity at age 11 and alcoholism at age 23. P3 deficits at age 11 are associated with adult crime at age 23, suggesting that reduced P3 may be an early neurobiological marker for cognitive and affective processes subserved by the temporal-parietal junction that place a child at risk for adult crime.

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

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

P3 event-related potentials and childhood maltreatment in successful and unsuccessful psychopaths

Although P3 event-related potential abnormalities have been found in psychopathic individuals, it is unknown whether successful (uncaught) psychopaths and unsuccessful (caught) psychopaths show similar deficits. In this study, P3 amplitude and latency were assessed from a community sample of 121 male adults using an auditory three-stimulus oddball task. Psychopathy was assessed using the Psychopathy Checklist-Revised (Hare, 2003) while childhood physical maltreatment was assessed using the Conflict Tactic Scale (Straus, 1979). Results revealed that compared to normal controls, unsuccessful psychopaths showed reduced parietal P3 amplitudes to target stimuli and reported experienced more physical abuse in childhood. In contrast, successful psychopaths exhibited larger parietal P3 amplitude and shorter frontal P3 latency to irrelevant nontarget stimuli than unsuccessful psychopaths. This is the first report of electrophysiological processing differences between successful and unsuccessful psychopaths, possibly indicating neurocognitive and psychosocial distinctions between these two subtypes of psychopathy.

Neurocognitive deficits in male alcoholics: an ERP/sLORETA analysis of the N2 component in an equal probability Go/NoGo task

In alcoholism research, studies concerning time-locked electrophysiological aspects of response inhibition have concentrated mainly on the P3 component of the event-related potential (ERP). The objective of the present study was to investigate the N2 component of the ERP to elucidate possible brain dysfunction related to the motor response and its inhibition using a Go/NoGo task in alcoholics. The sample consisted of 78 abstinent alcoholic males and 58 healthy male controls. The N2 peak was compared across group and task conditions. Alcoholics showed significantly reduced N2 peak amplitudes compared to normal controls for Go as well as NoGo task conditions. Control subjects showed significantly larger NoGo than Go N2 amplitudes at frontal regions, whereas alcoholics did not show any differences between task conditions at frontal regions. Standardized low resolution electromagnetic tomography analysis (sLORETA) indicated that alcoholics had significantly lower current density at the source than control subjects for the NoGo condition at bilateral anterior prefrontal regions, whereas the differences between groups during the Go trials were not statistically significant. Furthermore, NoGo current density across both groups revealed significantly more activation in bilateral anterior cingulate cortical (ACC) areas, with the maximum activation in the right cingulate regions. However, the magnitude of this difference was much less in alcoholics compared to control subjects. These findings suggest that alcoholics may have deficits in effortful processing during the motor response and its inhibition, suggestive of possible frontal lobe dysfunction.

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

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

Psychopaths are impaired in social exchange and precautionary reasoning

Psychopaths show a profound lack of morality and behavioral controls in the presence of intact general intellectual functioning. Two hallmarks of psychopathy are the persistent violation of social contracts (i.e., cheating) and chronic, impulsive risky behavior. These behaviors present a puzzle: Can psychopaths understand and reason about what counts as cheating or risky behavior in a particular situation? We tested incarcerated psychopaths' and incarcerated nonpsychopaths' reasoning about social contract rules, precautionary rules, and descriptive rules using the Wason selection task. Results were consistent with our hypotheses: Psychopaths (compared with matched nonpsychopaths) showed significant impairment on social contract rules and precautionary rules, but not on descriptive rules. These results cannot be accounted for by differences in intelligence, motivation, or general antisocial tendency. These findings suggest that examination of evolutionarily identified reasoning processes can be a fruitful research approach for identifying which specific mechanisms are impaired in psychopathy.

Treatment of psychopathy: a review and brief introduction to the mental model approach for psychopathy

Psychopathy is thought by many to be an untreatable disorder. This article puts the treatment of psychopathy into historical context and reviews research on the treatment of the disorder with adults (K = 8) and youth (K = 5). Findings indicate that treatment for adults shows low to moderate success with three of eight studies demonstrating treatment gains. Treatment of youth appears to be more promising with six of eight studies showing treatment benefits. Although less than optimal success rates with adults, we suggest that bright line distinctions regarding the treatability of those with psychopathic characteristics from non-psychopathic individuals are inappropriate at this time. We conclude with directions for future research and briefly introduce the mental models approach for the treatment of psychopathy in youths.

The neurobiology of psychopathy: a neurodevelopmental perspective

We provide an overview of the neurobiological underpinnings of psychopathy. Cognitive and affective-emotional processing deficits are associated with abnormal brain structure and function, particularly the amygdala and orbitofrontal cortex. There is limited evidence of lower cortisol levels being associated with psychopathic personality. Initial developmental research is beginning to suggest that these neurobiological processes may have their origins early in life. Findings suggest that psychopathic personality may, in part, have a neurodevelopmental basis. Future longitudinal studies delineating neurobiological correlates of the analogues of interpersonal-affective and antisocial features of psychopathy in children are needed to further substantiate a neurodevelopmental hypothesis of psychopathy.

Chronic alcoholism: insights from neurophysiology

INTRODUCTION

Increasing knowledge of the anatomical structures and cellular processes underlying psychiatric disorders may help bridge the gap between clinical signs and basic physiological processes. Accordingly, considerable insight has been gained in recent years into a common psychiatric condition, i.e., chronic alcoholism.

MATERIAL AND METHODS

We reviewed various physiological parameters that are altered in chronic alcoholic patients compared to healthy individuals--continuous electroencephalogram, oculomotor measures, cognitive event-related potentials and event-related oscillations--to identify links between these physiological parameters, altered cognitive processes and specific clinical symptoms.

RESULTS

Alcoholic patients display: (1) high beta and theta power in the resting electroencephalogram, suggesting hyperarousal of their central nervous system; (2) abnormalities in smooth pursuit eye movements, in saccadic inhibition during antisaccade tasks, and in prepulse inhibition, suggesting disturbed attention modulation and abnormal patterns of prefrontal activation that may stem from the same prefrontal "inhibitory" cortical dysfunction; (3) decreased amplitude for cognitive event-related potentials situated along the continuum of information-processing, suggesting that alcoholism is associated with neurophysiological deficits at the level of the sensory cortex and not only disturbances involving associative cortices and limbic structures; and (4) decreased theta, gamma and delta oscillations, suggesting cognitive disinhibition at a functional level.

DISCUSSION

The heterogeneity of alcoholic disorders in terms of symptomatology, course and outcome is the result of various pathophysiological processes that physiological parameters may help to define. These alterations may be related to precise cognitive processes that could be easily monitored neurophysiologically in order to create more homogeneous subgroups of alcoholic individuals.

Psychopathy, attention and emotion

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

Psychophysiological correlates of aggression and violence: an integrative review

This paper reviews existing psychophysiological studies of aggression and violent behaviour including research employing autonomic, electrocortical and neuroimaging measures. Robust physiological correlates of persistent aggressive behaviour evident in this literature include low baseline heart rate, enhanced autonomic reactivity to stressful or aversive stimuli, enhanced EEG slow wave activity, reduced P300 brain potential response and indications from structural and functional neuroimaging studies of dysfunction in frontocortical and limbic brain regions that mediate emotional processing and regulation. The findings are interpreted within a conceptual framework that draws on two integrative models in the literature. The first is a recently developed hierarchical model of impulse control (externalizing) problems, in which various disinhibitory syndromes including aggressive and addictive behaviours of different kinds are seen as arising from common as well as distinctive aetiologic factors. This model represents an approach to organizing these various interrelated phenotypes and investigating their common and distinctive aetiologic substrates. The other is a neurobiological model that posits impairments in affective regulatory circuits in the brain as a key mechanism for impulsive aggressive behaviour. This model provides a perspective for integrating findings from studies employing different measures that have implicated varying brain structures and physiological systems in violent and aggressive behaviour.

Structural brain abnormalities in psychopaths-a review

The biological basis of psychopathy has not yet been fully elucidated. Few studies deal with structural neuroimaging in psychopaths. The aim of this article is to review these studies in order to contribute to our understanding of the biological basis of psychopathy. Data in the literature report a reduction in prefrontal gray matter volume, gray matter loss in the right superior temporal gyrus, amygdala volume loss, a decrease in posterior hippocampal volume, an exaggerated structural hippocampal asymmetry, and an increase in callosal white matter volume in psychopathic individuals. These findings suggest that psychopathy is associated with brain abnormalities in a prefrontal-temporo-limbic circuit-i.e. regions that are involved, among others, in emotional and learning processes. Additionally, data indicate that psychopathic individuals cannot be seen as a homogeneous group. The associations between structural changes and psychopathic characteristics do not enable causal conclusions to be drawn, but point rather to the important role of biological brain abnormalities in psychopathy. To gain a comprehensive understanding of this, psychopathy must be viewed as a multifactorial process involving neurobiological, genetic, epidemiological and sociobiographical factors.

Temporal Stability of Auditory Event-Related Potentials in Healthy Individuals and Patients With Traumatic Brain Injury

Historically, cognitive event-related potentials (ERPs) have received limited acceptance for clinical use due to lack of evidence for their reliability. However, recent advances in computer technology and artifact rejection methods have greatly enhanced the fidelity of ERP measurements. The present study examined the test-retest reliability of ERP measurement by using current data processing methods. We assessed the temporal stability of the most commonly used ERP paradigm, auditory pure-tone "odd ball" detection, and compared it with other commonly used clinical measures reported in the literature. Auditory ERPs were collected in 19 healthy subjects and 7 patients with traumatic brain injury at two time points, 2 days to 2 months apart. Test-retest reliability was calculated for four ERP components: N1, MMN (mismatch negativity), P3, and N4. In healthy subjects, temporal stabilities of these four commonly studied ERP components' amplitude measurements were moderate to high, with intraclass correlations ranging from 0.6 to 0.8. In contrast, in patients with traumatic brain injury, ERPs were stable only for the N1 component (intraclass correlation = 0.7).

Cognitive deficits in children of alcoholics: At risk before the first sip!

BACKGROUND

High family loading for alcoholism, early onset of alcohol use and childhood disinhibitory behaviors, persisting into adulthood, increase the susceptibility to alcoholism. At the psychophysiology level, reduced amplitude of the P300 component of the Evoked Response Potential is associated with externalizing psychopathology in children. Children of alcoholics have reduced P300 amplitudes. Preliminary data suggests a developmental lag phenomenon in the maturation of the P300.

AIMS

The study compares the amplitude and topography of the P300 generated in response to a visual task, between subjects at high risk (HR) and those at low risk (LR) for alcoholism and its relation to externalizing behaviors.

RESULTS

HR subjects have lower P300 amplitudes over frontal brain areas. Differences are greater in young, tending to converge with increasing age. There is a strong association between this reduced brain activation and an excess of externalizing behaviors in HR individuals.

CONCLUSION

A maturational lag in brain development causing central nervous system disinhibition and externalizing behaviors may underlie the susceptibility to alcoholism.

Reduced Frontal Lobe Activity in Subjects With High Impulsivity and Alcoholism

OBJECTIVE

Impulsivity is an important characteristic of many psychiatric disorders, including substance-related disorders. These disinhibitory disorders have a similar underlying genetic diathesis, with each disorder representing a different expression of the same underlying genetic liability. This study assessed whether there is a relationship between impulsivity and alcohol dependence, and their correlations with P3 (P300) amplitude, a proposed endophenotype of alcoholism.

METHODS

Healthy control subjects (n=58) and subjects with DSM-IV diagnosis of alcohol dependence (n=57) were assessed with a visual oddball task. Event-Related Potentials (ERPs) were recorded from 61 scalp electrodes and P3 amplitudes measured. Barratt Impulsiveness Scale (BIS), version 11, was used to evaluate impulsivity. Source localization of P3 was computed using low-resolution brain electromagnetic tomography (LORETA).

RESULTS

Alcoholic subjects manifested reductions in target P3 amplitudes (p<0.0001). Using LORETA, significantly reduced activation was mapped in the cingulate, medial, and superior frontal regions in alcoholic subjects and highly impulsive subjects. Alcoholic subjects had significantly higher scores on the BIS (p<0.0001) than nonalcoholic individuals. There were significant negative correlations between total scores on BIS and P3 amplitude (r=-0.274, p=0.003, on Pz; r=-0.250, p=0.007, on Cz).

CONCLUSIONS

Our results demonstrate a strong frontal focus of reduced activation during processing of visual targets in alcoholic subjects and individuals with higher impulsivity. The findings suggest that impulsivity may be an important factor that underlies the pathogenesis of alcohol dependence. Studies are underway to examine the relationship between impulsivity and ERPs in offspring of alcoholic subjects, and to identify genes associated with the underlying predisposition involved in disinhibitory disorders.

Brain potentials implicate temporal lobe abnormalities in criminal psychopaths

Psychopathy is associated with abnormalities in attention and orienting. However, few studies have examined the neural systems underlying these processes. To address this issue, the authors recorded event-related potentials (ERPs) while 80 incarcerated men, classified as psychopathic or nonpsychopathic via the Hare Psychopathy Checklist--Revised (R. D. Hare, 1991, 2003), completed an auditory oddball task. Consistent with hypotheses, processing of targets elicited larger frontocentral negativities (N550) in psychopaths than in nonpsychopaths. Psychopaths also showed an enlarged N2 and reduced P3 during target detection. Similar ERP modulations have been reported in patients with amygdala and temporal lobe damage. The data are interpreted as supporting the hypothesis that psychopathy may be related to dysfunction of the paralimbic system--a system that includes parts of the temporal and frontal lobes.

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

Psychopathy is a complex personality disorder that includes interpersonal and affective traits such as glibness, lack of empathy, guilt or remorse, shallow affect, and irresponsibility, and behavioral characteristics such as impulsivity, poor behavioral control, and promiscuity. Much is known about the assessment of psychopathy; however, relatively little is understood about the relevant brain disturbances. The present review integrates data from studies of behavioral and cognitive changes associated with focal brain lesions or insults and results from psychophysiology, cognitive psychology and cognitive and affective neuroscience in health and psychopathy. The review illustrates that the brain regions implicated in psychopathy include the orbital frontal cortex, insula, anterior and posterior cingulate, amygdala, parahippocampal gyrus, and anterior superior temporal gyrus. The relevant functional neuroanatomy of psychopathy thus includes limbic and paralimbic structures that may be collectively termed 'the paralimbic system'. The paralimbic system dysfunction model of psychopathy is discussed as it relates to the extant literature on psychopathy.

Neurocognitive functions in pathological gambling: a comparison with alcohol dependence, Tourette syndrome and normal controls

AIMS

Neurocognitive functions in pathological gambling have relevance for the aetiology and treatment of this disorder, yet are poorly understood. This study therefore investigated neurocognitive impairments of executive functions in a group of carefully screened Diagnostic and Statistical Manual version IV (DSM-IV-TR) pathological gamblers. Performance was compared to a group of normal control participants. To study the specificity of these neurocognitive deficits, a substance dependence group (alcohol dependence) and an impulse control disorder group (Tourette syndrome) were included.

DESIGN

Cross-sectional study.

SETTING

Addiction and general mental health treatment centres.

PARTICIPANTS

Forty-nine pathological gamblers, 48 abstinent alcohol-dependent patients, 46 participants with Tourette syndrome and 49 normal control participants.

MEASUREMENTS

A comprehensive neuropsychological battery measuring executive functions as well as basic cognitive functions.

FINDINGS

Both the pathological gambling and the alcohol dependent groups were characterized by diminished performance on inhibition, time estimation, cognitive flexibility and planning tasks. The Tourette syndrome group showed deficits only on inhibition tasks. Basic cognitive functions were intact in all clinical groups. Comorbid attention deficit hyperactivity disorder, antisocial personality disorder and nicotine dependence influenced the impaired functions of the clinical groups only minimally.

CONCLUSIONS

Carefully screened groups of pathological gamblers and alcohol dependents were characterized by diminished executive functioning, suggesting a dysfunction of frontal lobe circuitry in these disorders. The resemblance between the pathological gambling group and the alcohol dependence group suggests a common neurocognitive aetiology for these disorders. Psychosocial treatment of these disorders could benefit from assessing and targeting deficits in executive functions, as they probably influence the course of these disorders negatively.