Neural correlates of automatic emotion regulation and their association with suicidal ideation in adolescents during the first 90-days of residential care

BACKGROUND

Suicide is the second leading cause of death for adolescents in the United States. However, relatively little is known about the forms of atypical neuro-cognitive function that are correlates of suicidal ideation (SI). One form of cognitive/affective function that, when dysfunctional, is associated with SI is emotion regulation. However, very little work has investigated the neural correlates of emotion dysregulation in adolescents with SI.

METHODS

Participants (N = 111 aged 12-18, 32 females, 31 [27.9%] reporting SI) were recruited shortly after their arrival at a residential care facility where they had been referred for behavioral and mental health problems. Daily reports of SI were collected during the participants' first 90-days in residential care. Participants were presented with a task-fMRI measure of emotion regulation - the Affective Number Stroop task shortly after recruitment. Participants were divided into two groups matched for age, sex and IQ based on whether they demonstrated SI.

RESULTS

Participants who demonstrated SI showed increased recruitment of regions including dorsomedial prefrontal cortex/supplemental motor area and parietal cortex during task (congruent and incongruent) relative to view trials in the context of emotional relative to neutral distracters.

CONCLUSIONS

Participants with SI showed increased recruitment of regions implicated in executive control during the performance of a task indexing automatic emotion regulation. Such data might suggest a relative inefficiency in the recruitment of these regions in individuals with SI.

Latent profiles of substance use, early life stress, and attention/externalizing problems and their association with neural correlates of reinforcement learning in adolescents

BACKGROUND

Adolescent substance use, externalizing and attention problems, and early life stress (ELS) commonly co-occur. These psychopathologies show overlapping neural dysfunction in the form of reduced recruitment of reward processing neuro-circuitries. However, it is unclear to what extent these psychopathologies show common v. different neural dysfunctions as a function of symptom profiles, as no studies have directly compared neural dysfunctions associated with each of these psychopathologies to each other.

METHODS

In study 1, a latent profile analysis (LPA) was conducted in a sample of 266 adolescents (aged 13-18, 41.7% female, 58.3% male) from a residential youth care facility and the surrounding community to investigate substance use, externalizing and attention problems, and ELS psychopathologies and their co-presentation. In study 2, we examined a subsample of 174 participants who completed the Passive Avoidance learning task during functional magnetic resonance imaging to examine differential and/or common reward processing neuro-circuitry dysfunctions associated with symptom profiles based on these co-presentations.

RESULTS

In study 1, LPA identified profiles of substance use plus rule-breaking behaviors, attention-deficit hyperactivity disorder, and ELS. In study 2, the substance use/rule-breaking profile was associated with reduced recruitment of reward processing and attentional neuro-circuitries during the Passive Avoidance task (p < 0.05, corrected for multiple comparisons).

CONCLUSIONS

Findings indicate that there is reduced responsivity of striato-cortical regions when receiving outcomes on an instrumental learning task within a profile of adolescents with substance use and rule-breaking behaviors. Mitigating reward processing dysfunction specifically may represent a potential intervention target for substance-use psychopathologies accompanied by rule-breaking behaviors.

Different forms of childhood maltreatment have different impacts on the neural systems involved in the representation of reinforcement value

Background

The current study aimed to address two gaps in the literature on child maltreatment, reinforcement processing and psychopathology. First, the extent to which compromised reinforcement processing might be particularly associated with either neglect or abuse. Second, the extent to which maltreatment-related compromised reinforcement processing might be associated with particular symptom sets (depression, conduct problems, anxiety) or symptomatology more generally.

Methods

A sample of adolescents (N = 142) aged between 14 and 18 years with varying levels of prior maltreatment participated in this fMRI study. They were scanned while performing a passive avoidance learning task, where the participant learns to respond to stimuli that engender reward and avoid responding to stimuli that engender punishment. Maltreatment (abuse and neglect) levels were assessed with the Childhood Trauma Questionnaire (CTQ).

Results

We found that: (i) level of neglect, but not abuse, was negatively associated with differential BOLD responses to reward-punishment within the striatum and medial frontal cortex; and (ii) differential reward-punishment responses within these neglect-associated regions were particularly negatively associated with level of conduct problems.

Conclusion

Our findings demonstrate the adverse neurodevelopmental impact of childhood maltreatment, particularly neglect, on reinforcement processing. Moreover, they suggest a neurodevelopmental route by which neglect might increase the risk for conduct problems.

Reduced neural responsiveness to looming stimuli is associated with increased aggression

While neuro-cognitive work examining aggression has examined patients with conditions at increased risk for aggression or individuals self-reporting past aggression, little work has attempted to identify neuro-cognitive markers associated with observed/recorded aggression. The goal of the current study was to determine the extent to which aggression by youth in the first three months of residential care was associated with atypical responsiveness to threat stimuli. This functional MRI study involved 98 (68 male; mean age = 15.96 [sd = 1.52]) adolescents in residential care performing a looming threat task involving images of threatening and neutral human faces or animals that appeared to be either loom or recede. Level of aggression was negatively associated with responding to looming stimuli (irrespective of whether these were threatening or neutral) within regions including bilateral inferior frontal gyrus, right inferior parietal lobule, right superior/middle temporal gyrus and a region of right uncus proximal to the amygdala. These data indicate that aggression level is associated with a decrease in responsiveness to a basic threat cue-looming stimuli. Reduced threat responsiveness likely results in the individual being less able to represent the negative consequences that may result from engaging in aggression, thereby increasing the risk for aggressive episodes.

Neurobiological Basis of Reinforcement-Based Decision-Making in Adults With ADHD Treated With Lisdexamfetamine Dimesylate

Background: The objective of this study was to examine changes in the activation of the brain reward system following treatment with lisdexamfetamine (LDX) vs. placebo (PL) as a function of clinical improvement in attention deficit/hyperactivity disorder (ADHD) symptoms. Methods: Twenty adults with ADHD were included in a randomized cross-over study. Participants underwent two functional magnetic resonance imaging (fMRI) scans, after receiving 3 to 5 weeks of treatment with both LDX and PL. During scanning, participants performed the passive-avoidance learning task to assess reward-related learning using computational variables (e.g., estimated value and prediction error). Pre-treatment to post-treatment symptom change was assessed via the ADHD Rating Scale (ADHD-RS). The imaging contrasts were Object Choose or Object Refuse during the object choice component of the task, modulated by expected value (reward vs. nonreward cue), and Reward vs. Punishment during feedback, modulated by prediction error (expected vs. actual outcome). To address the primary objective, we performed group-level mass univariate analyses between pre-treatment to post-treatment percent change of the ADHD-RS total scores and the four contrast images under the choice and feedback conditions, with significance set at a whole-brain voxel-wise threshold of p < .05 with family-wise error (FWE) correction and an extent (cluster) threshold of 50 contiguous voxels. Results: Improvement in ADHD symptoms was accompanied by significant increases of brain activation during the Object Refuse, Reward and Punishment contrasts in a widespread network including left caudate and putamen, and right orbitofrontal cortex (i.e., reward-related signaling) and left middle frontal, superior frontal, and precentral gyri (i.e., executive control). Conclusions: These findings are the first to show that the increase in responsiveness of systems engaged in reward processing with LDX treatment is positively related to symptom improvement. Results support the hypothesis that LDX treatment may restore balance to dysfunction (e.g., hypoactivation) within the brain reward circuitry in adults with ADHD.

Alcohol use disorder and cannabis use disorder symptomatology in adolescents is associated with dysfunction in neural processing of future events

Two of the most commonly used substances by adolescents in the United States are cannabis and alcohol. Cannabis use disorder (CUD) and alcohol use disorder (AUD) are associated with impairments in decision-making processes. One mechanism for impaired decision-making in these individuals is thought to be an inability to adequately represent future events during decision-making. In the current study involving 112 adolescents, we used a comparative optimism task to examine the relationship between relative severity of CUD/AUD (as indexed by the CUD/AUD Identification Tests [CUDIT/AUDIT]) and atypical function within neural systems underlying affect-based neural represenation future events. Greater CUDIT scores were negatively related to responses within subgenual anterior and posterior cingulate cortex when processing high-intensity potential future positive and negative events. There was also a particularly marked negative relationship between CUD symptoms and blood oxygen level-dependent (BOLD) responses within visual and premotor cortices to high-intensity, negatively valenced potential future events. However, AUD symptom severity was not associated with dysfunction within these brain regions. These data indicate that relative risk/severity of CUD is associated with reduced responsiveness to future high-intensity events. This may impair decision-making where future significant consequences should guide response choice.

Modeling the Comorbidity of Cannabis Abuse and Conduct Disorder/Conduct Problems from a Cognitive Neuroscience Perspective

Objective: A cognitive neuroscience perspective seeks to understand behavior, in this case the comorbidity of cannabis abuse and conduct disorder/conduct problems, in terms of dysfunction in cognitive processes underpinned by neural processes. The goal of this review is to articulate a cognitive neuroscience account of this comorbidity. Methods: Literature on the following issues will be reviewed: (i) the longitudinal relationship between cannabis abuse and conduct disorder/conduct problems (CD/CP); (ii) the extent to which there are genetic and environmental (specifically maltreatment) factors that underpin this relationship; (iii) forms of neurocognitive function that are reported dysfunctional in CD/CP and also, when dysfunctional, appear to be risk factors for future cannabis abuse; and (iv) the extent to which cannabis abuse may further compromise these systems leading to increased future abuse and greater conduct problems. Results: CD/CP typically predate cannabis abuse. There appear to be shared genetic factors that contribute to the relationship between CD/CP and cannabis abuse. Moreover, trauma exposure increases risk for both cannabis abuse and CP/CD. One form of neurocognitive dysfunction, response disinhibition, that likely exacerbates the symptomatology of many individuals with CD also appears to increase the risk for cannabis abuse. The literature with respect to other forms of neurocognitive dysfunction remains inconclusive. Conclusions: Based on the literature, a causal model of the comorbidity of cannabis abuse and CD/CP is developed.

Psychometrics of a Brief Trauma Symptom Screen for Youth in Residential Care

Trauma screening is an important element for providing trauma-informed services to youth in residential care. Unfortunately, lack of time and resources may deter clinicians from conducting trauma screening at intake. This study tested the psychometric properties of the Brief Trauma Symptom Screen for Youth (BTSSY), which could be used during intake into residential care. Participants included 572 youth, ages 10-18 years (M = 14.28 years, SD = 2.31), of whom 58.9% were boys, 78.7% were Caucasian, 51.7% were youth receiving services in residential care, 15.6% were youth with clinical needs, and 32.7% were typically developing youth from the local community. Participants completed the BTSSY; other questionnaires of psychopathology, childhood maltreatment, and symptomology of posttraumatic stress disorder (PTSD); and diagnostic interviews, which were conducted by licensed psychiatrists. The total BTSSY score had a good composite reliability (CR) of .80 and was valid based on a significant positive correlation, r = .64, with the UCLA PTSD-Reaction Index. The BTSSY score was also fair, area under the curve = .75, at detecting a diagnosis of PTSD from a psychiatrist. Significant group differences in the BTSSY scores were found between youth with a diagnosis of PTSD and the other two groups, with moderate-to-large effect sizes, ds = 0.73-1.22. Preliminary results indicated the BTSSY may be a useful screening tool for identifying youth at residential care intake who may need additional assessment for PTSD. Limitations and implications for future research and practice are discussed.

Genetic underpinnings of callous-unemotional traits and emotion recognition in children, adolescents, and emerging adults

BACKGROUND

Callous-Unemotional (CU) and psychopathic traits are consistently associated with impaired recognition of others' emotions, specifically fear and sadness. However, no studies have examined whether the association between CU traits and emotion recognition deficits is due primarily to genetic or environmental factors.

METHODS

The current study used data from 607 Caucasian twin pairs (N = 1,214 twins) to examine the phenotypic and genetic relationship between the Inventory of Callous-Unemotional Traits (ICU) and facial emotion recognition assessed via the laboratory-based Facial Expression Labeling Task (FELT).

RESULTS

The uncaring/callous dimension of the ICU was significantly associated with impaired recognition of happiness, sadness, fear, surprise, and disgust. The unemotional ICU dimension was significantly associated with improved recognition of surprise and disgust. Total ICU score was significantly associated with impaired recognition of sadness. Significant genetic correlations were found for uncaring/callous traits and distress cue recognition (i.e. fear and sadness). The observed relationship between uncaring/callous traits and deficits in distress cue recognition was accounted for entirely by shared genetic influences.

CONCLUSIONS

The results of the current study replicate previous findings demonstrating impaired emotion recognition among youth with elevated CU traits. We extend these findings by replicating them in an epidemiological sample not selected or enriched for pathological levels of CU traits. Furthermore, the current study is the first to investigate the genetic and environmental etiology of CU traits and emotion recognition, and results suggest genetic influences underlie the specific relationship between uncaring/callous traits and distress cue (fear/sadness) recognition in others.

Association of Different Types of Childhood Maltreatment With Emotional Responding and Response Control Among Youths

Importance

Childhood maltreatment is associated with serious developmental consequences that may be different depending on the form of maltreatment. However, relatively little research has investigated this issue despite implications for understanding the development of psychiatric disorders after maltreatment.

Objective

To determine the association of childhood maltreatment and potential differential associations of childhood abuse or neglect with neural responsiveness within regions of the brain implicated in emotional responding and response control.

Design, Setting, and Participants

In this cross-sectional study, participants aged 10 to 18 years with varying levels of prior maltreatment as indexed by the Childhood Trauma Questionnaire (CTQ) were recruited from a residential care facility and the surrounding community. Blood oxygen level-dependent response data were analyzed via 2 analyses of covariance that examined 2 (sex) × 3 (task condition [view, congruent, incongruent]) × 3 (valence [negative, neutral, positive]) with Blom-transformed covariates: (1) total CTQ score; and (2) abuse and neglect subscores. Data were collected from April 1, 2016, to June 30, 2018. Data analyses occurred from June 10, 2018, to October 31, 2018.

Main Outcomes and Measures

Blood oxygenation level-dependent signals in response to an Affective Stroop task were measured via functional magnetic resonance imaging.

Results

The sample included 116 youths (mean [SD] age, 15.0 [2.2] years; 70 [60.3%] male). Fifteen participants reported no prior maltreatment. The remaining 101 participants (87.1%) reported at least some prior maltreatment, and 55 (54.5%) reported significant maltreatment, ie, total CTQ scores were greater than the validated CTQ score threshold of 40. There were significant total CTQ score × task condition associations within the bilateral postcentral gyrus, left precentral gyrus, midcingulate cortex, middle temporal gyrus, and superior temporal gyrus (left postcentral gyrus: F = 11.73; partial η2 = 0.14; right postcentral and precentral gyrus: F = 9.81; partial η2 = 0.10; midcingulate cortex: F = 12.76; partial η2 = 0.12; middle temporal gyrus: F = 13.24; partial η2 = 0.10; superior temporal gyrus: F = 10.33; partial η2 = 0.11). In all examined regions of the brain, increased maltreatment was associated with decreased differential responsiveness to incongruent task trials compared with view trials (left postcentral gyrus: r = -0.34; 95% CI, -0.17 to -0.51; right postcentral and precentral gyrus: r = -0.31; 95% CI, -0.14 to -0.49; midcingulate cortex: r = -0.36; 95% CI, -0.18 to -0.53; middle temporal gyrus: r = -0.35; 95% CI, -0.17 to -0.52; superior temporal gyrus: r = -0.37; 95% CI, -0.20 to -0.55). These interactions were particularly associated with level of abuse rather than neglect. A second analysis of covariance revealed significant abuse × task condition (but not neglect × task) interactions within the midcingulate cortex (F = 13.96; partial η2 = 0.11), right postcentral gyrus and inferior parietal lobule (F = 15.21; partial η2 = 0.12), left postcentral and precentral gyri (F = 11.16; partial η2 = 0.12), and rostromedial frontal cortex (F = 10.36; partial η2 = 0.08)). In all examined regions of the brain, increased abuse was associated with decreased differential responsiveness to incongruent task trials compared with view trials (midcingulate cortex: partial r = -0.33; P < .001; right postcentral gyrus and inferior parietal lobule: partial r = -0.41; P < .001; left postcentral and precentral gyri: partial r = -0.40; P < .001; and rostromedial frontal cortex: partial r = -0.40; P < .001).

Conclusions and Relevance

These data document associations of different forms of childhood maltreatment with atypical neural response. This suggests that forms of maltreatment may differentially influence the development of psychiatric pathology.

The Neurodevelopmental Basis of Early Childhood Disruptive Behavior: Irritable and Callous Phenotypes as Exemplars

The arrival of the Journal's 175th anniversary occurs at a time of recent advances in research, providing an ideal opportunity to present a neurodevelopmental roadmap for understanding, preventing, and treating psychiatric disorders. Such a roadmap is particularly relevant for early-childhood-onset neurodevelopmental conditions, which emerge when experience-dependent neuroplasticity is at its peak. Employing a novel developmental specification approach, this review places recent neurodevelopmental research on early childhood disruptive behavior within the historical context of the Journal. The authors highlight irritability and callous behavior as two core exemplars of early disruptive behavior. Both phenotypes can be reliably differentiated from normative variation as early as the first years of life. Both link to discrete pathophysiology: irritability with disruptions in prefrontal regulation of emotion, and callous behavior with abnormal fear processing. Each phenotype also possesses clinical and predictive utility. Based on a nomologic net of evidence, the authors conclude that early disruptive behavior is neurodevelopmental in nature and should be reclassified as an early-childhood-onset neurodevelopmental condition in DSM-5. Rapid translation from neurodevelopmental discovery to clinical application has transformative potential for psychiatric approaches of the millennium. [AJP at 175: Remembering Our Past As We Envision Our Future November 1938: Electroencephalographic Analyses of Behavior Problem Children Herbert Jasper and colleagues found that brain abnormalities revealed by EEG are a potential causal factor in childhood behavioral disorders. (Am J Psychiatry 1938; 95:641-658 )].

Heightened amygdala responsiveness in s-carriers of 5-HTTLPR genetic polymorphism reflects enhanced cortical rather than subcortical inputs: An MEG study

Short allele carriers (S-carriers) of the serotonin transporter gene (5-HTTLPR) show an elevated amygdala response to emotional stimuli relative to long allele carriers (LL-homozygous). However, whether this reflects increased responsiveness of the amygdala generally or interactions between the amygdala and the specific input systems remains unknown. It is argued that the amygdala receives input via a quick subcortical and a slower cortical pathway. If the elevated amygdala response in S-carriers reflects generally increased amygdala responding, then group differences in amygdala should be seen across the amygdala response time course. However, if the difference is a secondary consequence of enhanced amygdala-cortical interactions, then group differences might only be present later in the amygdala response. Using magnetoencephalography (MEG), we found an enhanced amygdala response to fearful expressions starting 40-50 ms poststimulus. However, group differences in the amygdala were only seen 190-200 ms poststimulus, preceded by increased superior temporal sulcus (STS) responses in S-carriers from 130 to 140 ms poststimulus. An enhanced amygdala response to angry expressions started 260-270 ms poststimulus with group differences in the amygdala starting at 160-170 ms poststimulus onset, preceded by increased STS responses in S-carriers from 150 to 160 ms poststimulus. These suggest that enhanced amygdala responses in S-carriers might reflect enhanced STS-amygdala connectivity in S-carriers. Hum Brain Mapp 38:4313-4321, 2017. © 2017 Wiley Periodicals, Inc.

Youth with substance abuse histories exhibit dysfunctional representation of expected value during a passive avoidance task

Individuals with substance abuse (SA) histories show impairment in the computations necessary for decision-making, including expected value (EV) and prediction error (PE). Neuroimaging findings, however, have been inconsistent. Sixteen youth with (SApositive) and 29 youth without (SAnegative) substance abuse histories completed a passive avoidance task while undergoing functional MRI. The groups did not significantly differ on age, gender composition or IQ. Behavioral results indicated that SApositive youth showed significantly less learning than SAnegative youth over the task. SApositive youth show problems representing EV information when attempting to avoid sub-optimal choices in bilateral inferior frontal gyrus and striatum. Furthermore, SApositive youth showed a significantly increased differential response to reward versus punishment feedback modulated by PE in posterior cingulate cortex relative to SAnegative youth. Disrupted decision-making is likely to exacerbate SA as a failure to represent EV during the avoidance of sub-optimal choices is likely to increase the likelihood of SA. With respect to the representation of PE, future work will be needed to clarify the impact of different substances on the neural systems underpinning PE representation. Moreover, interaction of age/development and substance abuse on PE signaling will need to be explored.

Dysfunctional representation of expected value is associated with reinforcement-based decision-making deficits in adolescents with conduct problems

BACKGROUND

Previous work has shown that patients with conduct problems (CP) show impairments in reinforcement-based decision-making. However, studies with patients have not previously demonstrated any relationships between impairment in any of the neurocomputations underpinning reinforcement-based decision-making and specific symptom sets [e.g. level of CP and/or callous-unemotional (CU) traits].

METHODS

Seventy-two youths [20 female, mean age = 13.81 (SD = 2.14), mean IQ = 102.34 (SD = 10.99)] from a residential treatment program and the community completed a passive avoidance task while undergoing functional MRI.

RESULTS

Greater levels of CP were associated with poorer task performance. Reduced representation of expected values (EV) when making avoidance responses within bilateral anterior insula cortex/inferior frontal gyrus (AIC/iFG) and striatum was associated with greater levels of CP but not CU traits.

CONCLUSIONS

The current data indicate that difficulties in the use of value information to motivate decisions to avoid suboptimal choices are associated with increased levels of CP (though not severity of CU traits). Moreover, they account for the behavioral deficits observed during reinforcement-based decision-making in youth with CP. In short, an individual's relative failure to utilize value information within AIC/iFG to avoid bad choices is associated with elevated levels of CP.

Theta band activity in response to emotional expressions and its relationship with gamma band activity as revealed by MEG and advanced beamformer source imaging

Neuronal oscillations in the theta and gamma bands have been shown to be important for cognition. Here we examined the temporal and spatial relationship between the two frequency bands in emotional processing using magnetoencephalography and an advanced dynamic beamformer source imaging method called synthetic aperture magnetometry. We found that areas including the amygdala, visual and frontal cortex showed significant event-related synchronization in both bands, suggesting a functional association of neuronal oscillations in the same areas in the two bands. However, while the temporal profile in both bands was similar in the amygdala, the peak in gamma band power was much earlier within both visual and frontal areas. Our results do not support a traditional view that the localizations of lower and higher frequencies are spatially distinct. Instead, they suggest that in emotional processing, neuronal oscillations in the gamma and theta bands may reflect, at least in visual and frontal cortex either different but related functional processes or, perhaps more probably, different computational components of the same functional process.

Amygdala and nucleus accumbens activation to emotional facial expressions in children and adolescents at risk for major depression

OBJECTIVE

Offspring of parents with major depressive disorder face a threefold higher risk for major depression than offspring without such family histories. Although major depression is a significant cause of morbidity and mortality, neural correlates of risk for major depression remain poorly understood. This study compares amygdala and nucleus accumbens activation in children and adolescents at high and low risk for major depression under varying attentional and emotional conditions.

METHOD

Thirty-nine juveniles, 17 offspring of parents with major depression (high-risk group) and 22 offspring of parents without histories of major depression, anxiety, or psychotic disorders (low-risk group) completed a functional magnetic resonance imaging study. During imaging, subjects viewed faces that varied in intensity of emotional expressions across blocks of trials while attention was unconstrained (passive viewing) and constrained (rate nose width on face, rate subjective fear while viewing face).

RESULTS

When attention was unconstrained, high-risk subjects showed greater amygdala and nucleus accumbens activation to fearful faces and lower nucleus accumbens activation to happy faces (small volume corrected for the amygdala and nucleus accumbens). No group differences emerged in amygdala or nucleus accumbens activation during constrained attention. Exploratory analysis showed that constraining attention was associated with greater medial prefrontal cortex activation in the high-risk than in the low-risk group.

CONCLUSIONS

Amygdala and nucleus accumbens responses to affective stimuli may reflect vulnerability for major depression. Constraining attention may normalize emotion-related neural function possibly by engagement of the medial prefrontal cortex; face-viewing with unconstrained attention may engage aberrant processes associated with risk for major depression.

Autism spectrum disorder and psychopathy: shared cognitive underpinnings or double hit?

BACKGROUND

We measured psychopathic traits in boys with autism spectrum disorder (ASD) selected for difficult and aggressive behaviour. We asked (i) whether psychopathic tendencies can be measured in ASD independent of the severity of autistic behaviour; (ii) whether individuals with ASD with callous-unemotional (CU) traits differ in their cognitive profile from those without such traits; and (iii) how the cognitive data from this study compare with previous data of youngsters with psychopathic tendencies.

METHOD

Twenty-eight ASD boys were rated on psychopathic tendencies, autistic traits and a range of cognitive measures assessing mentalizing ability, executive functions, emotion recognition and ability to make moral-conventional distinction.

RESULTS

Our results indicate that psychopathic tendencies are not related to severity of ASD. In addition, such tendencies do not seem to be related to core autistic cognitive deficits, specifically in 'mind-reading' or executive function. Boys with co-occurring ASD and CU tendencies share some behaviours and aspects of cognitive profile with boys who have psychopathic tendencies alone.

CONCLUSIONS

Callous/psychopathic acts in a small number of individuals with ASD probably reflect a 'double hit' involving an additional impairment of empathic response to distress cues, which is not part and parcel of ASD itself.

Neural substrates of choice selection in adults and adolescents: development of the ventrolateral prefrontal and anterior cingulate cortices

A heightened propensity for risk-taking and poor decision-making underlies the peak morbidity and mortality rates reported during adolescence. Delayed maturation of cortical structures during the adolescent years has been proposed as a possible explanation for this observation. Here, we test the hypothesis of adolescent delayed maturation by using fMRI during a monetary decision-making task that directly examines risk-taking behavior during choice selection. Orbitofrontal/ventrolateral prefrontal cortex (OFC/VLPFC) and dorsal anterior cingulate cortex (ACC) were examined selectively since both have been implicated in reward-related processes, cognitive control, and resolution of conflicting decisions. Group comparisons revealed greater activation in the OFC/VLPFC (BA 47) and dorsal ACC (BA 32) in adults than adolescents when making risky selections. Furthermore, reduced activity in these areas correlated with greater risk-taking performance in adolescents and in the combined group. Consistent with predictions, these results suggest that adolescents engage prefrontal regulatory structures to a lesser extent than adults when making risky economic choices.

Positive and negative affect differentially influence identification of facial emotions

Positive and negative affects may bias behavior toward approach to rewards and withdrawal from threat, particularly when the contingencies are ambiguous. The hypothesis was that positive and negative affects would associate predictably with identification of happy, disgusted, or angry expressions that may signal potentially rewarding or aversive social interactions. Healthy volunteers (n=86) completed affect ratings and a facial emotion task that employed morphed continua in which emotional expressions gradually decreased in ambiguity. Relations between mood and intensity thresholds for emotion identification were computed. Anhedonia (low positive affect) predicted thresholds for happy expressions (r=0.24; P=.026) whereas negative affect predicted thresholds for disgust (r=-0.25; P=.022). Even within a normal range of mood, mood predicted emotion identification, supporting constructs of positive and negative affect derived originally from self-report measures.

Neurocognitive models of aggression, the antisocial personality disorders, and psychopathy

This paper considers neurocognitive models of aggression and relates them to explanations of the antisocial personality disorders. Two forms of aggression are distinguished: reactive aggression elicited in response to frustration/threat and goal directed, instrumental aggression. It is argued that different forms of neurocognitive model are necessary to explain the emergence of these different forms of aggression. Impairments in executive emotional systems (the somatic marker system or the social response reversal system) are related to reactive aggression shown by patients with "acquired sociopathy" due to orbitofrontal cortex lesions. Impairment in the capacity to form associations between emotional unconditioned stimuli, particularly distress cues, and conditioned stimuli (the violence inhibition mechanism model) is related to the instrumental aggression shown by persons with developmental psychopathy.

A selective impairment in the processing of sad and fearful expressions in children with psychopathic tendencies

The processing of emotional expressions is fundamental for normal socialisation and interaction. Reduced responsiveness to the expressions of sadness and fear has been implicated in the development of psychopathy (R. J. R. Blair, 1995). The current study investigates the sensitivity of children with psychopathic tendencies to facial expressions. Children with psychopathic tendencies and a comparison group, as defined by the Psychopathy Screening Device (PSD; P. J. Frick & R. D. Hare, in press), were presented with a cinematic display of a standardised set of facial expressions that depicted sadness, happiness, anger, disgust, fear, and surprise. Participants observed as these facial expressions slowly evolved through 20 successive frames of increasing intensity. The children with psychopathic tendencies presented with selective impairments; they needed significantly more stages before they could successfully recognise the sad expressions and even when the fearful expressions were at full intensity were significantly more likely to mistake them for another expression. These results are interpreted with reference to an amygdala and empathy impairment explanation of psychopathy.

Somatic markers and response reversal: is there orbitofrontal cortex dysfunction in boys with psychopathic tendencies?

This study investigated the performance of boys with psychopathic tendencies and comparison boys, aged 9 to 17 years, on two tasks believed to be sensitive to amygdala and orbitofrontal cortex functioning. Fifty-one boys were divided into two groups according to the Psychopathy Screening Device (PSD, P. J. Frick & R. D. Hare, in press) and presented with two tasks. The tasks were the gambling task (A. Bechara, A. R. Damasio, H. Damasio, & S. W. Anderson, 1994) and the Intradimensional/Extradimensional (ID/ED) shift task (R. Dias, T. W. Robbins, & A. C. Roberts, 1996). The boys with psychopathic tendencies showed impaired performance on the gambling task. However, there were no group differences on the ID/ED task either for response reversal or extradimensional set shifting. The implications of these results for models of psychopathy are discussed.

Recognition of emotion in facial expressions and vocal tones in children with psychopathic tendencies

The authors investigated the ability of children with emotional and behavioral difficulties, divided according to their Psychopathy Screening Device scores (P. J. Frick & R. D. Hare, in press), to recognize emotional facial expressions and vocal tones. The Psychopathy Screening Device indexes a behavioral syndrome with two dimensions: affective disturbance and impulsive and conduct problems. Nine children with psychopathic tendencies and 9 comparison children were presented with 2 facial expression and 2 vocal tone subtests from the Diagnostic Analysis of Nonverbal Accuracy (S. Nowicki & M. P. Duke, 1994). These subtests measure the ability to name sad, fearful, happy, and angry facial expressions and vocal affects. The children with psychopathic tendencies showed selective impairments in the recognition of both sad and fearful facial expressions and sad vocal tone. In contrast, the two groups did not differ in their recognition of happy or angry facial expressions or fearful, happy, and angry vocal tones. The results are interpreted with reference to the suggestion that the development of psychopathic tendencies may reflect early amygdala dysfunction (R. J. R. Blair, J. S. Morris, C. D. Frith, D. I. Perrett, & R. Dolan, 1999).

Dissociation between 'theory of mind' and executive functions in a patient with early left amygdala damage

There have been recent suggestions that the amygdala may be involved in the development or mediation of 'theory of mind'. We report a patient, B.M., with early or congenital left amygdala damage who, by adulthood, had received the psychiatric diagnoses of schizophrenia and Asperger's syndrome. We conducted a series of experimental investigations to determine B.M.'s cognitive functioning. In line with his diagnoses, B.M. was found to be severely impaired in his ability to represent mental states. Following this, we conducted a second series of studies to determine B.M.'s executive functioning. In the literature, there have been frequent claims that theory of mind is mediated by general executive functioning. B.M. showed no indication of executive function impairment, passing 16 tests assessing his ability to inhibit dominant responses, create and maintain goal-related behaviours, and temporally sequence behaviour. The findings are discussed with reference to models regarding the role of the amygdala in the development of theory of mind and the degree of dissociation between theory of mind and executive functioning. We conclude that theory of mind is not simply a function of more general executive functions, and that executive functions can develop and function on-line, independently of theory of mind. Moreover, we conclude that the amygdala may play some role in the development of the circuitry mediating theory of mind.

Impaired social response reversal. A case of 'acquired sociopathy'

In this study, we report a patient (J.S.) who, following trauma to the right frontal region, including the orbitofrontal cortex, presented with 'acquired sociopathy'. His behaviour was notably aberrant and marked by high levels of aggression and a callous disregard for others. A series of experimental investigations were conducted to address the cognitive dysfunction that might underpin his profoundly aberrant behaviour. His performance was contrasted with that of a second patient (C.L.A.), who also presented with a grave dysexecutive syndrome but no socially aberrant behaviour, and five inmates of Wormwood Scrubs prison with developmental psychopathy. While J.S. showed no reversal learning impairment, he presented with severe difficulty in emotional expression recognition, autonomic responding and social cognition. Unlike the comparison populations, J.S. showed impairment in: the recognition of, and autonomic responding to, angry and disgusted expressions; attributing the emotions of fear, anger and embarrassment to story protagonists; and the identification of violations of social behaviour. The findings are discussed with reference to models regarding the role of the orbitofrontal cortex in the control of aggression. It is suggested that J.S.'s impairment is due to a reduced ability to generate expectations of others' negative emotional reactions, in particular anger. In healthy individuals, these representations act to suppress behaviour that is inappropriate in specific social contexts. Moreover, it is proposed that the orbitofrontal cortex may be implicated specifically either in the generation of these expectations or the use of these expectations to suppress inappropriate behaviour.

Selective impairment in the recognition of anger induced by diazepam

RATIONALE

Facial expressions appear to be processed by at least partially separable neuro-cognitive systems. Given this functional specialization of expression processing, it is plausible that these neurocognitive systems may also be dissociable pharmacologically.

OBJECTIVE

The present study therefore compared the effects of diazepam (15 mg) with placebo upon the ability to recognize emotional expressions.

METHODS

A double blind, independent group design was used to compare the effects of diazepam and matched placebo in 32 healthy volunteers. Participants were presented morphed facial expression stimuli following a paradigm developed for use with patients with brain damage and asked to name one of the six basic emotions (sadness, happiness, anger, disgust, fear and surprise).

RESULTS

Diazepam selectively impaired subjects' ability to recognize angry expressions but did not affect recognition of any other emotional expression.

CONCLUSIONS

The findings are interpreted as providing further support for the suggestion that there are dissociable systems responsible for processing emotional expressions. It is suggested that these findings may have implications for understanding paradoxical aggression sometimes elicited by benzodiazepines.

Dissociable neural responses to facial expressions of sadness and anger

Previous neuroimaging and neuropsychological studies have investigated the neural substrates which mediate responses to fearful, disgusted and happy expressions. No previous studies have investigated the neural substrates which mediate responses to sad and angry expressions. Using functional neuroimaging, we tested two hypotheses. First, we tested whether the amygdala has a neural response to sad and/or angry facial expressions. Secondly, we tested whether the orbitofrontal cortex has a specific neural response to angry facial expressions. Volunteer subjects were scanned, using PET, while they performed a sex discrimination task involving static grey-scale images of faces expressing varying degrees of sadness and anger. We found that increasing intensity of sad facial expression was associated with enhanced activity in the left amygdala and right temporal pole. In addition, we found that increasing intensity of angry facial expression was associated with enhanced activity in the orbitofrontal and anterior cingulate cortex. We found no support for the suggestion that angry expressions generate a signal in the amygdala. The results provide evidence for dissociable, but interlocking, systems for the processing of distinct categories of negative facial expression.

Cognitive impairment and its relationship to psychopathic tendencies in children with emotional and behavioral difficulties

This study investigated whether performance on the card playing task (Newman, Patterson, & Kosson, 1987) and the moral/conventional distinction measure predict level of childhood conduct problems as indexed by the Psychopathy Screening Device (Frick & Hare, in press). The card-playing task indexes the child's sensitivity to changes in reinforcement rate. The moral/conventional distinction measure indexes the child's sensitivity to the difference between moral transgressions which result in harm to another from conventional transgressions which more usually result in social disorder. The Psychopathy Screening Device indexes a behavioral syndrome that consists of two dimensions: affective disturbance and impulsive and conduct problems. Thirty-nine children with emotional and behavioral difficulties were presented with both measures. Performance on both measures did predict extent of behavioral disturbance. Moreover, there was a significant association between performance on the card playing tasks and the moral/conventional distinction. The results are interpreted within the response set modulation and violence inhibition mechanism models and by reference to recent work at the anatomical level.

Human mast cells stimulate vascular tube formation. Tryptase is a novel, potent angiogenic factor

The presence of mast cells near capillary sprouting sites suggests an association between mast cells and angiogenesis. However, the role of mast cells in blood vessel development remains to be defined. In an attempt to elucidate this relationship, we investigated the effect of human mast cells (HMC-1) and their products on human dermal microvascular endothelial cell (HDMEC) tube formation. Coculture of HMC-1 with HDMEC led to a dose-response increase in the network area of vascular tube growth. Moreover, the extent of neovascularization was enhanced greatly when HMC-1 were degranulated in the presence of HDMEC. Further examination using antagonists to various mast cell products revealed a blunted response (73-88% decrease) in the area of vascular tube formation if specific inhibitors of tryptase were present. Tryptase (3 microg/ml) directly added to HDMEC caused a significant augmentation of capillary growth, which was suppressed by specific tryptase inhibitors. Tryptase also directly induced cell proliferation of HDMEC in a dose-dependent fashion (2 pM-2 nM). Our results suggest that mast cells act at sites of new vessel formation by secreting tryptase, which then functions as a potent and previously unrecognized angiogenic factor.

The psychopathic individual: a lack of responsiveness to distress cues?

In this study, we investigated the psychophysiological responsiveness of psychopathic individuals to distress cues and to threatening and neutral stimuli. Eighteen psychopathic individuals and 18 incarcerated control individuals, identified using the Revised Psychopathy Checklist (Hare, 1991, The Hare Psychopathy Checklist-Revised, Toronto: Multi-Health Systems), were shown slides of these three types of stimuli, and their electrodermal responses were recorded. The psychopathic individuals showed (relative to the controls) reduced electrodermal responses to the distress cues. In contrast, the two groups did not differ in their electrodermal responses to the threatening stimuli and to the neutral stimuli. The results are interpreted within the Violence Inhibition Mechanism model (Blair, 1995, Cognition, 57, 1-29) of the psychopathic individual.

A cognitive developmental approach to mortality: investigating the psychopath

Various social animal species have been noted to inhibit aggressive attacks when a conspecific displays submission cues. Blair (1993) has suggested that humans possess a functionally similar mechanism which mediates the suppression of aggression in the context of distress cues. He has suggested that this mechanism is a prerequisite for the development of the moral/conventional distinction; the consistently observed distinction in subject's judgments between moral and conventional transgressions. Psychopaths may lack this violence inhibitor. A causal model is developed showing how the lack of this mechanism would explain the core behavioural symptoms associated with the psychopathic disorder. A prediction of such a causal model would be that psychopaths should fail to make the moral/conventional distinction. This prediction was confirmed. The implication of this finding for other theories of morality is discussed.

Renal arterial rupture complicating transluminal angioplasty: successful conservative management

Vessel rupture complicating transluminal angioplasty is an uncommon event, especially in the renal artery. The authors report such a case, which was treated with immediate balloon tamponade and did not require surgical intervention. Possible causes and appropriate management are discussed, as well as the need for reporting angioplasty-related complications to a registry being developed by the Society of Cardiovascular and Interventional Radiology.

Uptake and esterification of arachidonic acid by trophozoites of Giardia lamblia

Although trophozoites of Giardia lamblia have not been demonstrated to possess the capacity for synthesis of phospholipids, these protozoan parasites would be exposed to fatty acids within the human small intestine. We have evaluated the metabolic incorporation of arachidonic and palmitic acids by Giardia trophozoites. Trophozoites (2.25 X 10(6)) were incubated with 12 nM [3H]fatty acid for up to 60 min. Uptake of [3H]arachidonate by trophozoites was rapid, increasing from 37% at 1 min to 65% at 10 min. Uptake of palmitate was rapid but less extensive. In contrast to palmitate, almost all of the trophozoite-associated [3H]arachidonate was esterified into phospholipids and neutral lipids. By 1 and 60 min 37% and 82% of [3H]arachidonate, respectively, were incorporated into phospholipids, including phosphatidylinositol and phosphatidylcholine. Peak incorporation of [3H]arachidonate into phosphatidylcholine (30 mmol [3H]fatty acid (mol phospholipid)-1) occurred at 60 min; whereas incorporation into the pool of phosphatidylinositol, which accounted for only 4% of trophozoite phospholipid, was maximal at 10 min (190 mmol [3H]fatty acid (mol phospholipid)-1) and declined significantly thereafter as arachidonic acid was released from phosphatidylinositol. Therefore, Giardia trophozoites not only utilize exogenous fatty acids in the formation of glycerolipids but also preferentially incorporate arachidonic acid into a metabolically active pool of phosphatidylinositol.

Neisseria meningitidis serogroup W 135 disease in adults

Five adults had infection caused by Neisseria meningitidis serogroup W135. Their ages ranged from 19 to 74 years, and the spectrum of illness included meningitis, pneumonia, and acute peritonitis. Two patients had systemic lupus erythematosus and were receiving corticosteroids at the time of their infection. One patient died of fulminant meningococcemia. All isolates were sensitive to sulfonamides. The recent increase in the national incidence of N meningitidis serogroup W135 infections emphasizes the need for continuing surveillance and justifies its inclusion in a polyvalent meningococcal vaccine.

Technetium-99m-labeled stannous imidodiphosphate, a new radiodiagnostic agent for bone scanning: comparison with other 99mTc complexes

Imidodiphosphate (IDP) is an analog of pyrophosphate and diphosphonate, with a P-N-P bond instead of P-O-P or P-C-P. We have labeled IDP with 99mTc quantitatively (98%) using stannous ions as the reducing/complexing agent in a freeze-dried kit form. Radiobioassay of this compound was carried out in rabbits and the results were compared with those of eight other Tc-labeled bone-imaging agents, using the performance of simultaneously administered 85Sr as a reference standard. The 99mTc-IDP concentrated 20% higher in the bone, and its soft-tissue and blood levels were lower than with 85Sr. By comparison, the concentrations in the bone of the other 99mTc agents were 20% less than that of 85Sr. Regarding blood levels, Tc-IDP performed worse than the Tc-diphosphonate but better than the pyrophosphate and the other technetium complexes. Scintillation camera images of 99mTc-IDP in both rabbits and dogs showed excellent details of the skeleton. In a preliminary human study, images with 99mTc-IDP were somewhat inferior to those comparably procured with 99Tc-methylene diphosphonate, but count rates with the IDP complex were about twice those with the MDP compound. Because of its better bone uptake, however, it is suggested that 99mTc-IDP may be clinically useful in spite of its relatively slow blood clearance.

Technetium-99m-methylene diphosphonate--a superior agent for skeletal imaging: comparison with other technetium complexes

Methylene diphosphonate (MDP) was formulated as a complex of 99mTc for skeletal imaging. This agent was compared with three other bone-seeking technetium agents: ethane-1-hydroxy-1, 1-diphosphonate (EHDP), pyrophosphate, and polyphosphate. In tissue radioassay experiments in rodents, the technetium complexes of MDP and EHDP were similar, but skeletal concentration with both of these agents was higher than that with pyrophosphate or polyphosphate. The total-body retention of MDP and EHDP complexed with 95mTc was studied in beagle dogs for 35 days by excretion measurements and total-body counting and compared with polyphosphate and pertechnetate. The long-term retention was greater for MDP. The 5-day cumulative fecal excretion of 95mTc was low when administered as EHDP or polyphosphate complexes and negligible when administered as MDP complex. In six human volunteers the blood clearance of 99mTc-mdp was similar to that of 18F and significantly faster than that of 99mTc-EHDP. Pyrophosphate cleared from the blood much faster than polyphosphate but slower than the diphosphonates. The urinary excretion of the MDP complex was greater than for EHDP within the first 2-3 hr after injection. The 24-hr urinary excretion of pyrophosphate and polyphosphate complexes was not as complete as for the diphosphonates. All four 99mTc complexes proved satisfactory for clinical imaging studies. The MDP complex produced images of superior quality as early as 2 hr after administration, attributable to its more rapid clearance from the blood and soft tissues. On the contrary, a longer interval of 3-4 hr after injection was usually needed for 99mTc-EHDP; pyrophosphate and polyphosphate complexes regularly required a waiting period of 4 hr. Comparitive radiation dose estimates were made based on the available biologic distribution data for these 99mTc skeletal-localizing agents.

Comparison of 99mTc complexes for renal imaging

The distribution of 17 different agents for renal imaging was compared in the rabbit by organ radioassay at 1 hr. Similarly, 99mTc complexes of iron-ascorbate, glucoheptonate (GHA) and 2,3-dimercaptosuccinic acid (DMS), and 203Hg-chlormerodrin were compared in the dog. The distribution of 99mTc-GHA and DMS was assessed in the human by blood and urinary clearance, external renal measurements, and scintillation camera imaging, and compared with older renal radiopharmaceuticals. Radiation dose estimates, based chiefly on human data, were calculated. Technetium-99m-DMS reaches a high concentration in the renal cortex and its urinary excretion rate and blood clearance are slow. It is excellent for imaging the renal parenchyma without activity in pelvocalyceal collecting system. However, it readily oxidizes and must be used within 30 min of preparation. The biologic distribution of 99mTc-GHA is similar to gluconate and iron-ascorbate complex. Its renal concentration is not as great as that of DMS but its blood and urinary clearances are much faster, resulting in lower radiation doses to most organs. Early camera images with this agent usually demonstrate both the renal parenchyma and collecting system. In later images, ther is excellent demonstration of the parenchyma alone, superior to that obtained with 99mTc-Sn-DTPA. It is a very stable complex and may be used for at least 5 hr after preparation. All radioactive renal agents examined to date have a significant concentration in the liver, making an accurate quantitative comparison between the two kidneys difficult.