Age-related alteration of emotional regulation in the BACHD rat model of Huntington disease

Huntington's disease (HD) is a genetic neurodegenerative disorder, caused by an expanded CAG repeat in the gene encoding the huntingtin protein. At the premanifest phase, before motor symptoms occur, psychiatric and emotional disorders are observed with high prevalence in HD patients. Agitation, anxiety and irritability are often described but also depression and/or apathy, associated with a lack of emotional control. The aim of the present study was to better circumscribe and understand the emotional symptoms and assess their evolution according to the progression of the disease using a transgenic HD model, BACHD rats, at the age of 4, 12 and 18 months. To achieve this goal, we confronted animals to two types of tests: first, tests assessing anxiety like the light/dark box and the conflict test, which are situations that did not involve an obvious threat and tests assessing the reactivity to a present threat using confrontation with an unknown conspecific (social behavior test) or with an aversive stimulus (fear conditioning test). In all animals, results show an age-dependent anxiety-like behavior, particularly marked in situation requiring passive responses (light/dark box and fear conditioning tests). BACHD rats exhibited a more profound alteration than WT animals in these tests from an early stage of the disease whereas, in tasks requiring some kind of motivation (for food or for social contacts), only old BACHD rats showed high anxiety-like behavior compared to WT, may be partly due to the other symptoms' occurrence at this stage: locomotor difficulties and/or apathy.

Infant behavioral inhibition predicts personality and social outcomes three decades later

Does infant temperament predict adult personality and life-course patterns? To date, there is scant evidence examining relations between child temperament and adult outcomes, and extant research has relied on limited methods for measuring temperament such as maternal report. This prospective longitudinal study followed a cohort of infants (n = 165) for three decades to examine whether infant behavioral inhibition, a temperament characterized by cautious and fearful behaviors to unfamiliar situations, shapes long-term personality, social relationships, vocational/education, and mental health outcomes in adulthood. At age 14 mo, behavioral inhibition was assessed using an observation paradigm. In adolescence (15 y; n = 115), error monitoring event-related potentials were measured in a flanker task. In adulthood (26 y; n = 109), personality, psychopathology, and sociodemographics were self-reported using questionnaires. We found that infants with higher levels of behavioral inhibition at 14 mo grew up to become more reserved and introverted adults (β = 0.34) with lower social functioning with friends and family (β = -0.23) at age 26. Infant behavioral inhibition was also a specific risk factor for adult internalizing (i.e., anxiety and depression, β = 0.20) psychopathology, rather than a transdiagnostic risk for general and externalizing psychopathology. We identified a neurophysiologic mechanism underlying risk and resilience for later psychopathology. Heightened error monitoring in adolescence moderated higher levels of adult internalizing psychopathology among behaviorally inhibited individuals. These findings suggest meaningful continuity between infant temperament and the development of adult personality. They provide the earliest evidence suggesting that the foundation of long-term well-being is rooted in individual differences in temperament observed in infancy.

Understanding the origins of child-teacher dependency: mother-child attachment security and temperamental inhibition as antecedents

This study investigated the joint contribution of child-mother attachment quality and child temperamental inhibition to the development of child-teacher dependency. A sample of 237 kindergartners (M_age = 60.2 months) and their teachers from 36 classrooms participated. Preschool child-mother attachment quality was assessed using the Attachment Q-set. Behavioral inhibition was rated by the preschool teacher. Dependency was assessed at three waves during kindergarten, using observer and teacher reports. In line with assumptions from attachment theory, less securely attached children were observed to be more overly reliant on their teacher in class. For behavioral inhibition, a divergent picture emerged depending on the assessment of dependency: Classroom observations yielded less (overt) indications of dependency among more inhibited children, whereas teachers reported more (covert) expressions of dependency. These results suggest that different measures may capture different aspects of the multifaceted construct of dependency, thus calling for more conceptual and empirical work.

Child-teacher dependency: The state of the research

The purpose of this commentary is to situate the findings from the studies in this special issue within the broader child-teacher relationship literature, with particular focus on the complex nature of child-teacher dependency. First, I briefly describe and review each of the compelling papers in this special issue. Second, I weave the studies to each other by linking their methods and results, and by identifying similar findings from the extant literature. Third, I provide some thoughts about future directions and implications for the study of child-teacher dependency from my perspective as a researcher in this field.

Life stress moderates the effects of preschool behavioral inhibition on anxiety in early adolescence

BACKGROUND

Although a robust body of literature implicates temperamental behavioral inhibition (BI) as a prominent risk factor for anxiety disorders, many children with heightened BI do not develop anxiety. The current study examines the role of two forms of life stress (life events and natural disaster exposure) in moderating the relationship between BI in preschoolers and anxiety in early adolescence.

METHOD

A community sample of 392 3-year-old children was administered a laboratory observational assessment of temperament. When children were a mean age 10, the region was struck by a devastating hurricane and exposure to disaster-related stress was assessed. In early adolescence, youth and a parent were administered the UCLA Life Stress Interview (LSI) to assess behaviorally independent and dependent negative life events during the prior year and youth completed the Screen for Child Anxiety Related Emotional Disorders (SCARED).

RESULTS

The association between early childhood BI and anxiety symptoms in early adolescence was moderated by both independent life events and disaster-related stress. Children high in BI at age 3 reported greater anxiety symptoms at age 12 after exposure to higher levels of both forms of stress.

CONCLUSIONS

Stress moderated the association between early BI and later anxiety. Importantly, this was evident for two different kinds of stressors that were independent of the child's behavior that increases confidence in the causal role of stress in the development of anxiety in high BI children.

Behavioral inhibition moderates the association between overvaluation of shape and weight and noncompensatory purging in eating disorders

OBJECTIVE

The cognitive-behavioral therapy (CBT) model of eating disorders suggests that compensatory purging behaviors (e.g., self-induced vomiting, inappropriate laxative use) are primarily driven by binge eating. However, many individuals endorse purging in the absence of binge eating (i.e., noncompensatory purging [NCP]). Research is needed to understand why some individuals purge in the absence of objective or subjective binge-eating episodes.

METHOD

Given the importance of overvaluation of shape/weight in the CBT model, and the existing evidence linking temperamental characteristics like behavioral inhibition (i.e., the tendency to withdraw in response to threat cues) with purging in general, we tested whether behavioral inhibition moderated the relationship between overvaluation of shape/weight and NCP in a sample of individuals in a residential eating disorder treatment center (N = 143).

RESULTS

Overvaluation was more strongly related to NCP in individuals with high (relative to low) levels of behavioral inhibition. Among individuals low in behavioral inhibition, overvaluation predicted engagement in NCP to a much weaker extent.

DISCUSSION

For those high (relative to low) in behavioral inhibition, both emotional avoidance and overvaluation may be important targets in the treatment of NCP, particularly in the absence of binge eating.

Levels of early-childhood behavioral inhibition predict distinct neurodevelopmental pathways to pediatric anxiety

BACKGROUND

Anxiety symptoms gradually emerge during childhood and adolescence. Individual differences in behavioral inhibition (BI), an early-childhood temperament, may shape developmental paths through which these symptoms arise. Cross-sectional research suggests that level of early-childhood BI moderates associations between later anxiety symptoms and threat-related amygdala-prefrontal cortex (PFC) circuitry function. However, no study has characterized these associations longitudinally. Here, we tested whether level of early-childhood BI predicts distinct evolving associations between amygdala-PFC function and anxiety symptoms across development.

METHODS

Eighty-seven children previously assessed for BI level in early childhood provided data at ages 10 and/or 13 years, consisting of assessments of anxiety and an fMRI-based dot-probe task (including threat, happy, and neutral stimuli). Using linear-mixed-effects models, we investigated longitudinal changes in associations between anxiety symptoms and threat-related amygdala-PFC connectivity, as a function of early-childhood BI.

RESULTS

In children with a history of high early-childhood BI, anxiety symptoms became, with age, more negatively associated with right amygdala-left dorsolateral-PFC connectivity when attention was to be maintained on threat. In contrast, with age, low-BI children showed an increasingly positive anxiety-connectivity association during the same task condition. Behaviorally, at age 10, anxiety symptoms did not relate to fluctuations in attention bias (attention bias variability, ABV) in either group; by age 13, low-BI children showed a negative anxiety-ABV association, whereas high-BI children showed a positive anxiety-ABV association.

CONCLUSIONS

Early-childhood BI levels predict distinct neurodevelopmental pathways to pediatric anxiety symptoms. These pathways involve distinct relations among brain function, behavior, and anxiety symptoms, which may inform diagnosis and treatment.

Sex Differences in the Association between Cortical Thickness and Children's Behavioral Inhibition

AIM

To investigate sex differences in the association between cortical thickness and behavioral inhibition of 9-10 years old American children.

MATERIALS AND METHODS

This cross-sectional investigation used data from the Adolescent Brain Cognitive Development (ABCD) study. Baseline ABCD data of 10249 American children between ages 9 and 10 were analyzed. The independent variable was cortical thickness measured by structural brain magnetic resonance imaging (sMRI). The primary outcome, behavioral inhibition, was measured based on the behavioral inhibition system (BIS), and behavioral approach system (BAS). Sex was the moderator. Age, race, ethnicity, socioeconomic status indicators, and intracranial volume were covariates.

RESULTS

In the overall sample, high cortical thickness was not associated with behavioral inhibition in children. Sex showed a statistically significant interaction with cortical thickness's effect on children's behavioral inhibition, net of all confounders. The interaction indicated a statistically stronger positive effect of high cortical thickness on male behavioral inhibition compared to female children.

CONCLUSION

Cortical thickness is a determinant of behavioral inhibition for male but not female American children. Male but not female children show better behavioral inhabitation at higher levels of cortical thickness.

Partial Predictability in Avoidance Acquisition and Expression of Wistar-Kyoto and Sprague-Dawley Rats: Implications for Anxiety Vulnerability in Uncertain Situations

Individual differences or vulnerabilities must exist which bias some individuals toward psychopathology while others remain resilient in the face of trauma. Recent work has studied the effects of uncertainty on individuals expressing behavioral inhibition (BI). The current study extended this work with uncertainty to Wistar Kyoto (WKY) rats which are a behaviorally inhibited inbred strain that models learning vulnerabilities for anxiety disorders and posttraumatic stress disorder (PTSD). WKY rats exhibit superior avoidance performance in a signaled bar press avoidance task in which a tone conditioned stimulus (CS) signals a foot shock unconditional stimulus (US) when compared with non-inhibited Sprague-Dawley (SD) rats. In addition, WKY rats express enhanced eyeblink conditioning. Recent work with behaviorally inhibited humans has indicated that this enhanced eyeblink conditioning is more evident in conditions that insert CS- or US-alone trials into CS-US paired training, resulting in uncertain and suboptimal learning conditions. The current study examined the effects of partial predictability training, in which the CS signaled the US only one-half of the time, on the acquisition and expression of avoidance. Standard training with a fixed 60-s CS which predicted shock on 100% of trials was compared with training in which the CS predicted shock on 50% of trials (partial predictability) using a pseudorandom schedule. As expected, WKY rats acquired avoidance responses faster and to a greater degree than SD rats. Partial predictability of the US essentially reduced SD rats to escape responding. Partial predictability also reduced avoidance in WKY rats; however, adjusting avoidance rates for the number of potential pairings of the CS and US early in training suggested a similar degree of avoidance expression late in the last session of training. Enhanced active avoidance expression, even in uncertain learning conditions, can be interpreted as behaviorally inhibited WKY rats responding to the expectancy of the shock by avoiding, whereas non-inhibited SD rats were responding to the presence of the shock by escaping. Future work should explore how WKY and SD rats as well as behaviorally inhibited humans acquire and extinguish avoidance responses in uncertain learning situations.

Stationary and ambulatory attention patterns are differentially associated with early temperamental risk for socioemotional problems: Preliminary evidence from a multimodal eye-tracking investigation

Behavioral Inhibition (BI) is a temperament type that predicts social withdrawal in childhood and anxiety disorders later in life. However, not all BI children develop anxiety. Attention bias (AB) may enhance the vulnerability for anxiety in BI children, and interfere with their development of effective emotion regulation. In order to fully probe attention patterns, we used traditional measures of reaction time (RT), stationary eye-tracking, and recently emerging mobile eye-tracking measures of attention in a sample of 5- to 7-year-olds characterized as BI (N = 23) or non-BI (N = 58) using parent reports. There were no BI-related differences in RT or stationary eye-tracking indices of AB in a dot-probe task. However, findings in a subsample from whom eye-tracking data were collected during a live social interaction indicated that BI children (N = 12) directed fewer gaze shifts to the stranger than non-BI children (N = 25). Moreover, the frequency of gazes toward the stranger was positively associated with stationary AB only in BI, but not in non-BI, children. Hence, BI was characterized by a consistent pattern of attention across stationary and ambulatory measures. We demonstrate the utility of mobile eye-tracking as an effective tool to extend the assessment of attention and regulation to social interactive contexts.

Consequences of Not Planning Ahead: Reduced Proactive Control Moderates Longitudinal Relations Between Behavioral Inhibition and Anxiety

OBJECTIVE

Children with the temperament of behavioral inhibition (BI) face increased risk for developing an anxiety disorder later in life. However, not all children with BI manifest anxiety symptoms, and use of a cognitive control strategy could moderate the pathway between BI and anxiety. Individuals vary widely in the strategy used to instantiate control. The present study examined whether a more planful style of cognitive control (ie, proactive control) or a more impulsive strategy of control (ie, reactive control) would moderate the association between early BI and later anxiety symptoms.

METHOD

Participants were part of a longitudinal study examining the relations between BI (measured at 2-3 years of age) and later anxiety symptoms (measured at 13 years). Use of a cognitive control strategy was assessed at 13 years using the AX variant of the continuous performance task.

RESULTS

BI in toddlerhood significantly predicted increased use of a more reactive cognitive control style in adolescence. In addition, cognitive control strategy moderated the relation between BI and anxious symptoms, such that reliance on a more reactive strategy predicted higher levels of anxiety for children high in BI.

CONCLUSION

The present study is the first to identify the specific control strategy that increases risk for anxiety. Thus, it is not cognitive control per se, but the specific control strategy children adopt that could increase risk for anxiety later in life. These findings have important implications for future evidence-based interventions because they suggest that an emphasis on decreasing reactive cognitive control and increasing proactive cognitive control might decrease anxious cognition.

Hyperactive Child Syndrome and Estimated Life Expectancy at Young Adult Follow-Up: The Role of ADHD Persistence and Other Potential Predictors

OBJECTIVE

We examined if ADHD Combined Type or Presentation (ADHD-C) reduced estimated life expectancy (ELE) at young adulthood and if the persistence of ADHD to adulthood further adversely affected ELE.

METHOD

A young adult follow-up of 131 hyperactive and 71 control cases was used to derive 14 variables that were entered into a life expectancy calculator to generate ELE scores. Both ratings of executive function (EF) in everyday life and tests of EF and IQ were measured along with comorbid psychopathologies.

RESULTS

Childhood ADHD-C was associated with a 9.5-year reduction in healthy ELE, and a 8.4-year reduction in total ELE relative to control children by adulthood. The persistence of ADHD to adulthood was linked to a 12.7-year reduction in ELE. Several background traits accounted for more than 39% of variation in ELE.

CONCLUSION

Childhood ADHD-C predicts a significantly reduced ELE by adulthood, which is further reduced by the persistence of ADHD to adult follow-up.

Development of inhibitory control during childhood and its relations to early temperament and later social anxiety: unique insights provided by latent growth modeling and signal detection theory

BACKGROUND

Children with the temperament of behavioral inhibition (BI) face increased risk for social anxiety. However, not all children with BI develop anxiety symptoms. Inhibitory control (IC) has been suggested as a moderator of the pathway between BI and social anxiety. This study uses longitudinal data to characterize development of IC and tests the hypothesis that IC moderates associations between early BI and later social anxiety symptoms.

METHODS

Children completed a Go/Nogo task at ages 5, 7, and 10 years as part of a longitudinal study of BI (measured at 2-3 years) and social anxiety symptoms (measured at 12 years). To assess IC development, response strategy (criterion) and inhibitory performance (d') were characterized using signal detection theory. Latent growth models were used to characterize the development of IC and examine relations among BI, IC parameters, and social anxiety symptoms.

RESULTS

IC response strategy did not change between 5 and 10 years of age, whereas IC performance improved over time. BI scores in toddlerhood predicted neither initial levels (intercept) nor changes (slope) in IC response strategy or IC performance. However, between ages 5 and 10, rate of change in IC performance, but not response strategy, moderated relations between BI and later parent-reported social anxiety symptoms. Specifically, greater age-related improvements in IC performance predicted higher levels of social anxiety in high BI children.

CONCLUSIONS

IC development in childhood occurs independent of BI levels. However, rapid increases in IC performance moderate risk for social anxiety symptoms in children with BI. Implications for theory and practice are discussed.

Toward a Standardized Test of Fearful Temperament in Primates: A Sensitive Alternative to the Human Intruder Task for Laboratory-Housed Rhesus Macaques (Macaca mulatta)

Standardized and sensitive tests to assess differences in temperament among primates housed in captivity are essential for monitoring welfare and improving science outcomes through reduced noise in data. Fearful temperament in primates has traditionally been assessed using the Human Intruder Test (HIT) in which duration of bodily freeze in response to approach by an unknown human is measured. The HIT is susceptible to variation between facilities in execution, interpretation of data and could be stressful for animals with more fearful temperaments. We tested the applicability of a touch-screen task with putatively negative stimuli as a more standardizable and sensitive tool for measuring fearful temperament in laboratory primates. Seventeen adult male rhesus macaques were assessed for fearfulness using the HIT. They were then tested on a touch-screen task designed to measure two behavioral indices of fearfulness: behavioral inhibition and response-slowing. We predicted monkeys assessed as having more fearful temperament in the HIT, would show the greatest degree of behavioral inhibition and response-slowing to negative pictures in the touch-screen task. In Study 1, monkeys were rewarded with juice for touching gray squares on the screen (control trials). On test trials a picture of an unknown male conspecific face with direct-gaze (signaling threat) was shown. Monkeys were less likely to touch direct-gaze faces than control trials, indicating behavioral inhibition to threat. Behavioral inhibition was greatest amongst monkeys scored with most fearful temperament in the HIT. This primary result indicates the touch-screen task may be sensitive to a more subtle form of the bodily freeze behavior measured using the HIT. In Study 2, we tested whether these findings generalized to other classes of putatively negative stimuli; monkeys were shown pictures of the human intruder and objects associated with veterinary and husbandry procedures, interspersed with control trials (gray squares). There was no evidence of behavioral inhibition in Study 2. There was some evidence for response-slowing, which was greater for pictures of objects than pictures of the human intruder, and occurred independently of fearfulness in the HIT. We propose touch-screen tasks provide a more standardized and sensitive approach for assessing fearful temperament in laboratory primates.

Prediction and control of operant behavior: What you see is not all there is

Prediction and control of operant behavior are major goals of behavior analysis. We suggest that achieving these goals can benefit from doing more than identifying the three-term contingency between the behavior, its setting stimulus, and its consequences. Basic research now underscores the idea that prediction and control require consideration of the behavior's history. As one example, if an operant is a goal-directed action, it is controlled by the current value of the reinforcer, as illustrated by the so-called reinforcer devaluation effect. In contrast, if the behavior is a habit, it occurs automatically, without regard to the reinforcer's value, as illustrated by its insensitivity to the reinforcer devaluation effect. History variables that distinguish actions and habits include the extent of their prior practice and their schedule of reinforcement. Other operants can appear to have very low or zero strength. However, if the behavior has reached that level through extinction or punishment, it may precipitously increase in strength by changing the context, allowing time to pass, presenting the reinforcer contingently or noncontingently, or extinguishing an alternative behavior. Behaviors that are not suppressed by extinction or punishment are not affected the same way. When predicting the strength of an operant behavior, what you see is not all there is. The behavior's history counts.

Threat-related Attention Bias in Socioemotional Development: A Critical Review and Methodological Considerations

Cross-sectional evidence suggests that attention bias to threat is linked to anxiety disorders and anxiety vulnerability in both children and adults. However, there is a lack of developmental evidence regarding the causal mechanisms through which attention bias to threat might convey risks for socioemotional problems, such as anxiety. Gaining insights into this question demands longitudinal research to track the complex interplay between threat-related attention and socioemotional functioning. Developing and implementing reliable and valid assessments tools is essential to this line of work. This review presents theoretical accounts and empirical evidence from behavioral, eye-tracking, and neural assessments of attention to discuss our current understanding of the development of normative threat-related attention in infancy, as well as maladaptive threat-related attention patterns that may be associated with the development of anxiety. This review highlights the importance of measuring threat-related attention using multiple attention paradigms at multiple levels of analysis. In order to understand if and how threat-related attention bias in real-life, social interactive contexts can predict socioemotional development outcomes, this review proposes that future research cannot solely rely on screen-based paradigms but needs to extend the assessment of threat-related attention to naturalistic settings. Mobile eye-tracking technology provides an effective tool for capturing threat-related attention processes in vivo as children navigate fear-eliciting environments and may help us uncover more proximal bio-psycho-behavioral markers of anxiety.

The Genetic and Environmental Relationship Between Childhood Behavioral Inhibition and Preadolescent Anxiety

This study uses novel approaches to examine genetic and environmental influences shared between childhood behavioral inhibition (BI) and symptoms of preadolescent anxiety disorders. Three hundred and fifty-two twin pairs aged 9-13 and their mothers completed questionnaires about BI and anxiety symptoms. Biometrical twin modeling, including a direction-of-causation design, investigated genetic and environmental risk factors shared between BI and social, generalized, panic and separation anxiety. Social anxiety shared the greatest proportion of genetic (20%) and environmental (16%) variance with BI with tentative evidence for causality. Etiological factors underlying BI explained little of the risk associated with the other anxiety domains. Findings further clarify etiologic pathways between BI and anxiety disorder domains in children.

Similar Neural Correlates of Planning and Execution to Inhibit Continuing Actions

Inhibition of action is involved in stopping a movement, as well as terminating unnecessary movement during performance of a behavior. The inhibition of single actions, known as response inhibition (Inhibition of the urge to respond before or after actions) has been widely investigated using the go/no-go task and stop signal task. However, few studies focused on phase and volition-related inhibition after an action has been initiated. Here, we used functional magnetic resonance imaging (fMRI) to investigate the neural correlates of planning and execution underlying the voluntary inhibition of ongoing action. We collected fMRI data while participants performed a continuous finger-tapping task involving voluntary and involuntary (externally directed) inhibition, and during the initiation of movement. The results revealed areas of significantly greater activation during the preparation of inhibition of an ongoing action during voluntary inhibition, compared with involuntary inhibition, in the supplementary (SMA) and pre-supplementary motor areas, dorsolateral prefrontal cortex, inferior frontal gyrus (IFG), inferior parietal lobe, bilateral globus pallidus/putamen, bilateral insula and premotor cortex. Focusing on the period of execution of inhibition of ongoing actions, an event-related fMRI analysis revealed significant activation in the SMA, middle cingulate cortex, bilateral insula, right IFG and inferior parietal cortex. Additional comparative analyses suggested that brain activation while participants were planning to inhibit an ongoing action was similar to that during planning to start an action, indicating that the same neural substrates of motor planning may be recruited even when an action is ongoing. The present finding that brain activation associated with inhibiting ongoing actions was compatible with that seen in response inhibition (urge to stop before/after actions) suggests that common inhibitory mechanisms for motor movement are involved in both actual and planned motor action, which makes our behavior keep going seamlessly.

Anger Weakens Behavioral Inhibition Selectively in Contact Athletes

Studies have increasingly found that the aggression level of contact athletes is higher than that of non-athletes. Given that higher aggression levels are associated with worse behavioral inhibition and that athletes show better behavioral inhibition than non-athletes, it is unclear why contact athletes would exhibit higher aggression levels. Emotion, especially anger, is an important factor in the generation of aggressive behavior, and anger has been shown to affect behavioral inhibition. Thus, the present study examined the influence of anger on behavioral inhibition in contact athletes. An implicit emotional Go/No-go task was used that contained 50 anger-associated words and 50 neutral words as stimuli. Participants were asked to execute a key press depending on the explicit color of word and to ignore any (implicit) emotional information associated with the word. The results showed a significant interaction in performance accuracy on the No-go task between emotion (i.e., anger-associated words versus neutral words) and group (athlete versus non-athlete). The performance accuracy of the contact athletes on anger-associated stimuli was significantly lower than that for neutral stimuli. Evoked delta and theta oscillations were analyzed at the time windows 200–600 and 200–400 ms respectively in both groups. A time-frequency analysis indicated a significant interaction between group, emotion and task for both evoked delta and theta oscillations. Post hoc analyses showed that stronger evoked delta and theta oscillations were evoked during the presentation of anger-associated stimuli compared with neutral stimuli on the No-go task in athletes. By contrast, no other significant effect was found in the control group or between the control and athlete groups. These results indicate that time-frequency analysis can effectively distinguish conventional ERP components and that implicit anger significantly weakens behavioral inhibition in contact athletes but not in non-athletes.

Naturally Occurring Nonhuman Primate Models of Psychosocial Processes

Human research into psychological processes such as anxiety, depression, or loneliness typically involves accruing cases in which the phenomenon of interest is naturally occurring, and then comparing such a sample with control cases. In contrast, animal research designed to model similar processes to test mechanistic hypotheses typically involves inducing the phenomenon of interest via some exogenously (i.e., human) administered procedure. In the present review, the author proposes that naturally occurring animal models can complement induced models in understanding complex psychological phenomena. Advantages and disadvantages of naturally occurring versus induced models are described, and detailed examples of three naturally occurring models-for loneliness and health, behavioral inhibition and asthma, and social functioning and autism-are described, along with a formal program (the BioBehavioral Assessment program) at the California National Primate Research Center, that is designed to quantify variation in biobehavioral processes in infant rhesus macaques to facilitate development of naturally occurring models. It is argued that, because of the similarity in complex behavioral and psychological processes between macaques and humans, naturally occurring primate models provide a bridge between human studies and induced primate models and have the potential to identify new models for translational research.

Cats Parallel Great Apes and Corvids in Motor Self-Regulation - Not Brain but Material Size Matters

The inhibition of unproductive motor movements is regarded as a fundamental cognitive mechanism. Recently it has been shown that species with large absolute brain size or high numbers of pallial neurons, like great apes and corvids, show the highest performance on a task purportedly measuring this mechanism: the cylinder task. In this task the subject must detour a perpendicularly oriented transparent cylinder to reach a reward through a side opening, instead of directly reaching for it and bumping into the front, which is regarded as an inhibitory failure. Here we test domestic cats, for the first time, and show that they can reach the same levels as great apes and corvids on this task, despite having much smaller brains. We tested subjects with apparatuses that varied in size (cylinder length and diameter) and material (glass or plastic), and found that subjects performed best on the large cylinders. As numbers of successes decreased significantly when the cylinders were smaller, we conducted additionally two experiments to discern which properties (length of the transparent surface, goal distance from the surface, size of the side opening) affects performance. We conclude that sensorimotor requirements, which differ between species, may have large impact on the results in such seemingly simple and apparently comparable tests. However, we also conclude that cats have comparably high levels of motor self-regulation, despite the differences between tests.

Behavioral activation and behavioral inhibition sensitivities in patients with substance use disorders: A study from India

INTRODUCTION

Addictive disorders are an epiphenomenon of underlying vulnerabilities. Research over the past decades into these vulnerabilities has distinguished internalizing and externalizing spectra as two distinct personality factors underlying substance use disorders (SUDs). In this study, we explore the behavioral activation and inhibition factors in patients with SUD.

MATERIALS AND METHODS

A total of 240 patients with SUD were recruited for the study. Behavioral inhibition system-behavioral activation/approach system (BIS-BAS) scale was used to assess the three domains of the behavioral activation, namely drive, fun seeking and reward responsiveness, and the behavioral inhibition as a single domain. BIS and BAS subscale total scores, inter-domain correlation, factor structure, and difference in the early-onset and late-onset SUD subgroup scores were calculated.

RESULTS

The drive, fun seeking, and reward responsiveness showed a moderate degree of correlation among each other ranging from 0.30 to 0.36. The behavioral inhibition subscale had a modest correlation r = 0.26 with the reward responsiveness subdomain of behavioral activation. The factor structure remained valid at two- and four-factor solutions apart from few items with inconsistent loading. The early-onset n = 209 (87.1%) and late-onset n = 31 (12.9%) SUD subgroup analysis showed a statistically significant difference in the mean scores of drive and fun-seeking subscales with P < 0.05.

DISCUSSION AND CONCLUSIONS

Behavioral activation and inhibition remain two valid personality factors in patients with SUDs. Patients with early onset of SUD have a significantly higher behavioral activation scores in the drive, and fun-seeking subfactors suggesting a higher externalizing tendency.

Behavioral Inhibition Underlies the Link Between Interoceptive Sensitivity and Anxiety-Related Temperamental Traits

Interoceptive sensitivity (IS) is a biologically determined, constitutional trait of an individual. High IS has been often associated with proneness to anxiety. This association has been explained by elevated autonomic responsiveness in anxious individuals. However, in a heartbeat discrimination task (discrimination of heartbeats' simultaneity to an external stimulus) low cardiac responsiveness has accompanied enhanced performance. The relation between these factors seems task dependent, and cannot comprehensively explain the link between IS and anxiety. We explored for additional explanatory factors for this link. More specifically, we studied which anxiety-related temperamental traits most strongly predict IS in the discrimination task. Compatibly with earlier findings, IS was positively associated with individual trait anxiety and also other related traits such as negative affect, emotional intensity, and introversion. Interestingly, behavioral inhibition was the temperamental trait that most strongly predicted high IS, and, in fact, accounted for its significant associations with the other anxiety-related temperamental traits. Good performance on heartbeat discrimination task may reflect adaptive attentional control abilities in behaviorally inhibited individuals. These results can improve our understanding of how IS and other traits together determine the personality and wellbeing of a human individual.

Generalization of an Early Intervention for Inhibited Preschoolers to the Classroom Setting

Considerable evidence has accumulated supporting transactional influences between early childhood behavioral inhibition (BI), parent-child and child-peer relationships, and the development of anxiety disorders in adolescence and adulthood. Drawing from this literature, the Turtle Program was designed to treat children high in BI by intervening at the level of both parents and peers. In this pilot study, we sought to determine whether benefits of participating in the Turtle Program extended to children's classrooms in the form of increased positive social interactions with peers. Forty inhibited children (42-60 months) and their parent(s) were randomized to either the Turtle Program (n = 18) or a waitlist control group (WLC; n = 22). The Turtle Program involved 8 weeks of concurrent parent and child treatment. Trained research assistants, blind to treatment condition, coded participants' social interactions with peers during free play at each child's preschool at the beginning and end of treatment. Teachers unaware of group assignment also provided reports of social behaviors at these time points. Reliable change index scores revealed that both Turtle Program and WLC participants experienced relatively high rates of reliable increases in observed peer play interactions from pre- to post-treatment (73.3% and 42.1% respectively). Additionally, Turtle Program participants experienced high rates of reliable increase in observed initiations to peers (73.3%) as well as a moderate degree of reliable decrease in teacher-reported displays of fear/anxiety (33.3%). These data provide preliminary, but promising, evidence that increases in children's social behaviors as a result of participation in the Turtle Program generalize to their preschool classrooms.