Reduced neural responses to vocal fear: a potential biomarker for callous-uncaring traits in early childhood

Predictive Validity of Adolescent Callous-Unemotional Traits and Conduct Problems with Respect to Adult Outcomes: High- and Low-Risk Samples

Current understanding of the predictive validity of callous-unemotional (CU) traits is limited by (a) the focus on externalizing psychopathology and antisocial behaviors, (b) a lack of long-term prospective longitudinal data, (c) samples comprised of high-risk or low-risk individuals. We tested whether adolescent CU traits and conduct problems were associated with theoretically relevant adult outcomes 12-18 years later. Participants were drawn from two studies: higher-risk Fast Track (FT; n = 754) and lower-risk Child Development Project (CDP; n = 585). FT: conduct problems positively predicted externalizing and internalizing psychopathology and partner violence, and negatively predicted health, wellbeing, and education. Three conduct problems × CU traits interaction effects were also found. CDP: CU traits positively predicted depression and negatively predicted health and education; conduct problems positively predicted externalizing and internalizing psychopathology and substance use, and negatively predicted wellbeing. CU traits did not provide incremental predictive validity for multiple adult outcomes relative to conduct problems.

Some critical considerations in applying the construct of psychopathy to research and classification of childhood disruptive behavior disorders

The recent inclusion of callous-unemotional traits in the diagnostic criteria for serious conduct problems has led to renewed interest in more comprehensive integrations of the construct of psychopathy into research and clinical classification of childhood disruptive behavior disorders. There have been a number of recent reviews of research focusing the many potential benefits for this integration. However, there are also a number of issues that could reduce these benefits and even potentially lead to harmful effects. The current paper focuses on several of these issues, some of which are common when attempting to integrate research findings across areas that have been conducted independently of each other. Other issues are more specific to the construct of psychopathy. Specifically, the current paper focuses on the lack of agreement on the necessary and sufficient dimensions needed to define psychopathy, the need to consider developmental relationships among these dimensions, the implications of the different associations among the dimensions of psychopathy with conduct problems in children and adolescents, the need to consider how these dimensions relate to existing constructs used in the classification of disruptive behavior disorders, and the potential harmful effects of labeling something "a dimension of psychopathy". These issues have several clear implications for using the construct of psychopathy to guide research on and diagnostic classification of childhood disruptive behavior disorders.

Genetic and environmental influences on the developmental trajectory of callous-unemotional traits from childhood to adolescence

BACKGROUND

This study examined the genetic and environmental influences underlying baseline level and developmental course of callous-unemotional (CU) traits across childhood and adolescence.

METHODS

The data on 8,958 twin pairs (3,108 MZ twin pairs and 5,850 DZ twin pairs) from the Twins Early Development Study were analysed. CU traits were assessed at ages 7, 9, 12 and 16 by mothers and analysed using a biometric latent growth model.

RESULTS

Individual differences in the baseline level of CU traits were highly heritable (76.5%), while the heritability of the developmental course of CU traits was moderate (43.6%). The genetic influences on baseline level and developmental course of CU traits were mostly nonoverlapping. Nonshared environment made a modest contribution to the baseline level of CU traits (21.7%). Nonshared environmental influences on the developmental course of CU traits were moderate (43.2%), with nearly half of them being the same as those influencing the baseline level and just over half being specific. Shared environmental effects did not contribute to systematic change across childhood and adolescence but were rather age-specific.

CONCLUSIONS

Our findings demonstrate that rather than only being conceptualized as factors of stability, genes also play a dynamic role in explaining systematic change in CU traits. Genetic effects for the initial risk and subsequent development of CU traits are not the same. In addition to genetic factors, nonshared environmental influences play an important role in explaining why some children will increase or maintain their CU traits over time, whereas other will desist. New genetic and environmental influences with age suggest that repeated, age-tailored interventions may be required throughout development to make a lasting difference in the presentation of CU traits and associated outcomes.

The Hoosier Vocal Emotions Corpus: A validated set of North American English pseudo-words for evaluating emotion processing

This article presents the development of the "Hoosier Vocal Emotions Corpus," a stimulus set of recorded pseudo-words based on the pronunciation rules of English. The corpus contains 73 controlled audio pseudo-words uttered by two actresses in five different emotions (i.e., happiness, sadness, fear, anger, and disgust) and in a neutral tone, yielding 1,763 audio files. In this article, we describe the corpus as well as a validation study of the pseudo-words. A total of 96 native English speakers completed a forced choice emotion identification task. All emotions were recognized better than chance overall, with substantial variability among the different tokens. All of the recordings, including the ambiguous stimuli, are made freely available, and the recognition rates and the full confusion matrices for each stimulus are provided in order to assist researchers and clinicians in the selection of stimuli. The corpus has unique characteristics that can be useful for experimental paradigms that require controlled stimuli (e.g., electroencephalographic or fMRI studies). Stimuli from this corpus could be used by researchers and clinicians to answer a variety of questions, including investigations of emotion processing in individuals with certain temperamental or behavioral characteristics associated with difficulties in emotion recognition (e.g., individuals with psychopathic traits); in bilingual individuals or nonnative English speakers; in patients with aphasia, schizophrenia, or other mental health disorders (e.g., depression); or in training automatic emotion recognition algorithms. The Hoosier Vocal Emotions Corpus is available at https://psycholinguistics.indiana.edu/hoosiervocalemotions.htm.

Diminished Neural Responses to Emotionally Valenced Facial Stimuli: A Potential Biomarker for Unemotional Traits in Early Childhood

Callous-unemotional (CU) traits are characterized by deficits in guilt/empathy, shallow affect, and the callous and manipulative use of others. Individuals showing CU traits have increased risk for behavior problems and reduced responses to displays of distress in others. To explore how deficits in emotion-processing are associated with CU traits, the current study examined the association between callous-unemotionality and a neural index of facial emotion processing, using the event-related potential technique in a group of 3-5 year olds. Children viewed a series of static emotional faces, depicting either fear or happiness, while electroencephalography data were collected. The N170 component, thought to index the neural processes associated with face perception, was examined along with CU traits. Findings suggest that the unemotional dimension of CU traits is associated with diminished emotion-processing responses to fearful faces. Reduced neural responses to facial depictions of fear could be a biomarker for unemotional traits in early childhood.

A longitudinal, within-person investigation of the association between the P3 ERP component and externalizing behavior problems in young children

BACKGROUND

Externalizing problems, including aggression and conduct problems, are thought to involve impaired attentional capacities. Previous research suggests that the P3 event-related potential (ERP) component is an index of attentional processing, and diminished P3 amplitudes to infrequent stimuli have been shown to be associated with externalizing problems and attention-deficit/hyperactivity disorder (ADHD). However, the vast majority of this prior work has been cross-sectional and has not examined young children. The present study is the first investigation of whether within-individual changes in P3 amplitude predict changes in externalizing problems, providing a stronger test of developmental process.

METHOD

Participants included a community sample of children (N = 153) followed longitudinally at 30, 36, and 42 months of age. Children completed an oddball task while ERP data were recorded. Parents rated their children's aggression and ADHD symptoms.

RESULTS

Children's within-individual changes in the P3 amplitude predicted concomitant within-child changes in their aggression such that smaller P3 amplitudes (relative to a child's own mean) were associated with more aggression symptoms. However, changes in P3 amplitudes were not significantly associated with ADHD symptoms.

CONCLUSIONS

Findings suggest that the P3 may play a role in development of aggression, but do not support the notion that the P3 plays a role in development of early ADHD symptoms.