Applying a traumatic stress approach to understanding PCS following pediatric mild TBI

Pediatric traumatic brain injury is a significant public health concern affecting hundreds of thousands of children each year. The majority of children who sustain traumatic brain injuries are classified as having a mild traumatic brain injury, and a subset of these children go on to experience persistent physical, cognitive, and emotional symptoms. These symptoms, known as postconcussive symptoms, can endure for months and even years after injury. The outcomes of mild traumatic brain injury are variable and not well understood for a small percentage of children who experience persistent symptoms. The current article explores the potential influence of children’s posttraumatic stress symptoms on persistent postconcussive symptoms. Despite the high incidence of posttraumatic stress symptoms after pediatric accidental injury, they have not yet been identified as an important factor for consideration in the understanding of pediatric postconcussive outcomes. The article will review the literature on posttraumatic stress and postconcussive symptoms after pediatric injury and consider neurobiological and cognitive factors to propose a model explaining a pathway through which posttraumatic stress reactions may serve as the mechanism for the expression and maintenance of postconcussive symptoms after mild traumatic brain injury. The clinical implications for the proposed relationship between posttraumatic stress symptoms and postconcussive symptoms are considered prior to the conclusion of the article, which acknowledges limitations in the current literature and provides suggestions for future research.     

Parent Report of Attention Problems Predicts Later Adaptive Functioning in Children with Brain Tumors

Children with brain tumors are at risk for psychological and behavioral difficulties. This study examined the ability of parent report of attention problems, withdrawal, anxiety, and depression, as well as IQ, to predict later adaptive functioning in 42 children treated for brain tumors. Age at diagnosis, SES, gender, and scores on the Neurological Predictor Scale (NPS) also were examined as predictors. Parent report of attention problems, SES, and NPS were significant predictors of later adaptive functioning across domains. This finding highlights the ability of parent report of attention problems to predict later adaptive functioning in children treated for brain tumors.     

Circuits and circumstances: the neurobiological consequences of early relationship experiences and how they shape later behaviour

The last decade has seen a vast increase in knowledge of how the human brain develops. It has been demonstrated that both the establishment of synaptic connections between neurones and the programming of neurochemical responses that have an effect on the whole body are dependent on experience. The most sensitive period for brain growth, the time of optimal plasticity, is over the first two or three years of life. If the baby's neurological development is threatened by abuse or neglect, which includes excessive attachment disruption, the damage may set its stamp on the rest of life.     

A time of change: Behavioral and neural correlates of adolescent sensitivity to appetitive and aversive environmental cues

Adolescence is a developmental period that entails substantial changes in affective and incentive-seeking behavior relative to both childhood and adulthood, including a heightened propensity to engage in risky behaviors and experience persistent negative and labile mood states. This review discusses the emotional and incentive-driven behavioral changes in adolescents and their associated neural mechanisms, focusing on the dynamic interactions between the amygdala, ventral striatum, and prefrontal cortex. Common behavioral changes during adolescence may be associated with a heightened responsiveness to incentives and emotional cues while the capacity to effectively engage in cognitive and emotion regulation is still relatively immature. We highlight empirical work in humans and animals that addresses the interactions between these neural systems in adolescents relative to children and adults, and propose a neurobiological model that may account for the nonlinear changes in adolescent behavior. Finally, we discuss other influences that may contribute to exaggerated reward and emotion processing associated with adolescence, including hormonal fluctuations and the role of the social environment.     

Examining the relationships between self‐efficacy,task‐relevant attentional control,and task performance: Evidence from event‐related brain potentials

Self‐efficacy (SE) is a modifiable psychosocial factor related to individuals’ beliefs in their capabilities to successfully complete courses of action and has been shown to be positively associated with task performance. The authors hypothesized that one means through which SE is related with improved performance is through enhanced task‐relevant attentional control during task execution. To assess this hypothesis, we examined the relationships between SE and behavioural and neural indices of task performance and task‐relevant attentional control for 76 young adults during the completion of a flanker task. Results showed that greater SE was associated with greater response accuracy and P3b amplitude across task conditions, and faster RT under more difficult task conditions. Additionally, P3b amplitude was found to mediate the relationship between SE and task performance in the difficult condition. These findings suggest that greater attentional allocation to task‐relevant processes, including monitoring stimulus‐response relationships and focusing attention on working memory operations, may help explain the association between SE and improved task performance.     

The Empathy Quotient (EQ) predicts perceived strength of bodily illusions and illusion-related sensations of pain

In this study we test the possible implications of high empathising skills on bodily self–other distinction by measuring the strength of a body ownership illusion and a related experience of illusory pain. One-hundred adult participants completed the Empathy Quotient (EQ) questionnaire. Twenty participants from the top quintile and 20 participants from the bottom quintile of the EQ distribution took part in a laboratory experiment. In the experiment, a classical Rubber Hand Illusion (RHI) was induced followed by the presentation of a series of painful stimuli to the rubber hand. Participants were asked to self-rate the strength of their subjective experience of the RHI and of the illusory pain. A proprioceptive location judgment on the position of the hidden hand was also required before and after RHI induction, to record drifts towards the rubber hand. We found a significant difference between high- and low-empathy participants in RHI and pain score. The EQ was not related with the proprioceptive location judgement drift. It thus appears to be a better predictor of subjective ownership feelings and phenomenological self–other merging than of the behavioural components of bodily illusions.     

Reliability and validity of the Leuven Perceptual Organization Screening Test (L‐POST)

Neuropsychological tests of visual perception mostly assess high‐level processes like object recognition. Object recognition, however, relies on distinct mid‐level processes of perceptual organization that are only implicitly tested in classical tests. Furthermore, the psychometric properties of the existing instruments are limited. To fill this gap, the Leuven perceptual organization screening test (L‐POST) was developed, in which a wide range of mid‐level phenomena are measured in 15 subtests. In this study, we evaluated reliability and validity of the L‐POST. Performance on the test is evaluated relative to a norm sample of more than 1,500 healthy control participants. Cronbach's alpha of the norm sample and test–retest correlations for 20 patients provide evidence for adequate reliability of L‐POST performance. The convergent and discriminant validity of the test was assessed in 40 brain‐damaged patients, whose performance on the L‐POST was compared with standard clinical tests of visual perception and other measures of cognitive function. The L‐POST showed high sensitivity to visual dysfunction and decreased performance was specific to visual problems. In conclusion, the L‐POST is a reliable and valid screening test for perceptual organization. It offers a useful online tool for researchers and clinicians to get a broader overview of the mid‐level processes that are preserved or disrupted in a given patient.     

Shear-driven damage of ductile metals induced by indentation load

Although indentation does not induce apparent cracking in ductile materials, degradation of elastic stiffness of ductile metals has been found in micro-/macro- indentation tests. After comparing the predicted degradation by extended damaged-plasticity models with that measured by experimental testing, it is found that the softening caused by distortion of existing voids is inadequate to cause the notable degradation of elasticity. It is suggested that an independent damage-nucleation mechanism arising from shear deformation may exist. Although attractive in practical applications for its non-destructive nature, the damage-based indentation technique for estimating the fracture properties of ductile materials needs further investigation.