Regional brain electrical activity in posttraumatic stress disorder after motor vehicle accident

This study examined whether patients with posttraumatic stress disorder (PTSD) related to motor vehicle accidents (MVAs) would show an abnormal pattern of electroencephalographic (EEG) alpha asymmetries, which has been proposed for particular types of anxiety. Patients with PTSD (n = 22) or subsyndromal PTSD (n = 21), traumatized controls without PTSD (non-PTSD with MVA; n = 21), and healthy controls without MVA (n = 23) underwent measurement of EEG activity during baseline and exposure to a neutral, a positive, a negative, and an accident-related picture. Differences in brain asymmetry between groups were observed only during exposure to trauma-related material. PTSD and subsyndromal PTSD patients showed a pattern of enhanced right anterior and posterior activation, whereas non-PTSD with MVA participants showed the opposite pattern. Furthermore, posterior asymmetry in nontraumatized healthy controls varied with gender, with female participants showing a pattern of higher right posterior activation. The results support the hypothesis that symptomatic MVA survivors are characterized by a pattern of right hemisphere activation that is associated with anxious arousal and symptoms of PTSD during processing of trauma-specific information.     

Are trauma victims susceptible to "false memories"?

Laboratory studies using word-list paradigms have provided evidence that nontraumatized individuals falsely recall or recognize events that never occurred. In the present study, H. L. Roediger and K. B. McDermott's false-memory paradigm (1995) was utilized to examine possible source monitoring deficits in individuals with PTSD. Traumatized individuals with PTSD were compared with traumatized individuals without PTSD and with nontraumatized control participants. Participants heard lists of related words (e.g., bed, night) that were associates of a critical nonpresented word (e.g., sleep) and were given immediate free recall and later recognition tests. Traumatized participants with and without PTSD generated more false recalls of critical nonpresented words than did nontraumatized participants. False recall was related to trait anxiety and PTSD severity. The results are consistent with a general source-monitoring deficit in trauma-exposed individuals.     

The self-concept of traumatized children and adolescents with or without PTSD

This study compared the Piers-Harris 2 scores of youth with PTSD (n=30) to the scores of traumatized youth without PTSD (n=60) and a non-traumatized comparison group (n=39). In the absence of major comorbid disorders, youth with PTSD evidenced significantly lower scores than the traumatized PTSD negatives and controls on five of six Piers-Harris 2 scales. With the exception of scores on an index of perceived parental acceptance of child behavior, trauma exposure in the absence of PTSD was not associated with lower Piers-Harris 2 scores.     

The effectiveness of a school mindfulness-based intervention on the neural correlates of inhibitory control in children at risk: A randomized control trial

Interest in the applications of mindfulness practice in education is growing in the scientific community. Recent research has shown that mindfulness practice in schools may be beneficial for executive functions (EFs) which are abilities crucial for healthy development. The study of the effects of mindfulness practices on children's neural correlates of EFs, particularly inhibitory control, may provide relevant information about the impact and mechanisms of mindfulness-based interventions (MBIs) in children. The aim of the present study was to investigate the effects of a MBI in elementary school children on the neural correlates of inhibitory control via a randomized controlled trial. Children from two 4th grade classrooms and two 5th grade classrooms located in a school identified as having low socioeconomic status in Santiago de Chile were randomly assigned to either receive a MBI or serve as active controls and receive a social skills program. Both before and after the interventions, electroencephalographic activity was recorded during a modified version of the Go/Nogo task in a subsample of children in each group. Additionally, teachers completed questionnaires of students’ EFs and students completed self-report measures. Results revealed increases in EFs assessed by questionnaires together with improved P3 amplitude associated with successful response inhibition in children who received the MBI compared to active controls. These results contribute to the understanding of the ways in which mindfulness practices can promote the development of inhibitory control together with EF improvement, factors identified as critical for children's social and emotional development and positive mental health.

Research Highlights

• This study investigated the effects of a mindfulness-based intervention in children from a low socioeconomic status school on neural correlates of EFs.
• Children performed a Go/Nogo task while electroencephalographic activity was recorded and completed questionnaires before and after a MBI or an active control program.
• Improvements in EFs assessed by questionnaires together with an increased Nogo-P3 activity associated with successful inhibition in children who received the MBI were found.
• The results could contribute to understand how mindfulness practice can promote the development of inhibitory control in children from vulnerable populations.

     

Veridical and false memory for scenic material in posttraumatic stress disorder

The question whether memory aberrations in posttraumatic stress disorder (PTSD) also manifest as an increased production of false memories is important for both theoretical and practical reasons, but is yet unsolved. Therefore, for the present study we investigated veridical and false recognition in PTSD with a new scenic variant of the Deese-Roediger-McDermott (DRM) paradigm, which was administered to traumatized individuals with PTSD (n=32), traumatized individuals without PTSD (n=30), and non-traumatized controls (n=30). The PTSD group neither produced higher rates of false memories nor expressed more confidence in errors, but did show inferior memory sensitivity. Whereas depressive symptoms did not correlate with veridical nor false recognition, state dissociation was positively associated with false memories.     

Trauma exposure is associated with increased context-dependent adjustments of cognitive control in patients with posttraumatic stress disorder and healthy controls

Recent evidence has suggested that posttraumatic stress disorder (PTSD) is associated with alterations in prefrontal-cortex-dependent cognitive processes (e.g., working memory, cognitive control). However, it remains unclear whether these cognitive dysfunctions are related to PTSD symptomatology or trauma exposure. Furthermore, regarding cognitive control, research has only focused on the integrity of selected control functions, but not their dynamic regulation in response to changing environmental demands. Therefore, the present study investigated dynamic variations in interference control, in addition to overall interference susceptibility and working memory (WM) performance in matched groups of 24 PTSD patients and 26 traumatized and 30 nontraumatized healthy controls. The Simon task was used to measure overall interference susceptibility and the flexible adjustment of cognitive control, on the basis of the occurrence of response conflicts (conflict adaptation effect). WM performance was assessed with the forward and backward digit span tasks. Since we have previously shown that trauma exposure per se is associated with reduced hair cortisol concentrations (HCC), we further explored whether PTSD/trauma-related cognitive alterations are related to HCC in proximal 3-cm hair segments. The results revealed that PTSD patients and traumatized controls showed significantly more pronounced conflict adaptation effects than nontraumatized controls. Moreover, the conflict adaptation effect was positively related to the number of lifetime traumatic events and the frequency of traumatization. The groups did not differ in overall interference susceptibility or WM performance. Exploratory analyses revealed no association between HCC and the observed cognitive differences. These results suggest that context-driven control adjustments constitute a sensitive correlate of trauma exposure, irrespective of PTSD.     

Complementary assessments of executive function in preterm and full-term preschoolers

Executive functions (EFs) are interrelated cognitive processes that have been studied in relation to behavior, attention, academic achievement, and developmental disorders. Studies of EF skills assessed through parent report and performance-based measures show correlations between them ranging from none to modest. Few studies have examined the relationship between EF skills measured through parent report and performance-based measures in relation to adaptive function. The present study included preschool children born preterm as a population at high risk for EF impairments. Preschool children (N = 149) completed a battery of EF tasks that assess working memory, response inhibition, idea generation, and attention shifting or cognitive flexibility. Parents reported on children’s EF and adaptive skills. Preterm children showed more parent-rated and performance-based EF impairments than did full-term children. The combined use of either parent report or performance-based measures resulted in the identification of a large number of children at risk for EF impairment, especially in the preterm group. Both parent report and performance-based EF measures were associated with children’s adaptive function. EF skills are measurable in young child'ren, and we suggest that EF skills may serve as targets for intervention to improve functional outcomes. We recommend the use of both parent report and performance-based measures to characterize children’s EF profiles and to customize treatment.     

Moulding environmental contexts to optimise neurodiverse executive function performance and development: A goodness-of-fit account

Executive functions (EFs) provide a top-down response to stimuli and events in pursuit of a goal. We argue that the extent to which an individual's environment is enriching and a good fit for them influences whether their performance at that moment is towards their upper- or lower-limit of EF ability. We outline the implications of this for interpreting measures of EF. We next argue that a child's sensitivity to the environment, and their caregivers' ability to modulate the environment to improve goodness-of-fit, influences the cumulative effects of the environment in shaping that child's actualised EF ability (the performance level shown in day-to-day situations), and thus their skill development. We therefore recommend that EF interventions be designed to improve children's actualised EF ability by improving their day-to-day environment, while simultaneously helping children modulate their physiological response to environmental challenges, and providing opportunities to practise EF skills in ecologically-valid contexts.     

Early executive functioning in a global context: Developmental continuity and family protective factors

This study extends the methodological and theoretical understanding of executive functions (EFs) in preschoolers from low‐ and middle‐income countries (LMIC). First, the authors describe a rigorous process of adapting and evaluating six EF tasks to produce a culturally and developmentally appropriate measure of emerging EFs in a large sample of at‐risk children in rural Pakistan. Next, the authors identify critical developmental and family factors that relate to preschoolers’ EFs over the first 4 years of life. Direct assessment of children's general cognitive skills at age two showed developmental continuity with EFs at age four, and these early cognitive skills mediated the effect of an antecedent parenting intervention on EFs as well as associations of targeted individual and family factors with EFs. Furthermore, directly assessed maternal cognitive capacities and observed maternal scaffolding uniquely predicted EFs in preschoolers. This study is also the first to demonstrate a significant overlap between direct assessments of IQ and EFs in young children from LMIC. Children's general intelligence mediated the associations of EFs with antecedent physical growth and cognitive skills as well as concurrent family factors (maternal verbal intelligence, maternal scaffolding, and home stimulation). After controlling for shared variance between preschoolers’ general intelligence and EFs, three factors emerged as unique predictors of EFs: exposure to an early parenting intervention, physical growth status at age two, and number of older siblings. The findings have important implications for the design of interventions that aim to improve EFs in young children in LMIC. A video abstract of this article can be viewed at https://vimeo.com/316329544/5abde94cd7     

Developmental trajectories in toddlers' self-restraint predict individual differences in executive functions 14 years later: a behavioral genetic analysis

We examined whether self-restraint in early childhood predicted individual differences in 3 executive functions (EFs; inhibiting prepotent responses, updating working memory, and shifting task sets) in late adolescence in a sample of approximately 950 twins. At ages 14, 20, 24, and 36 months, the children were shown an attractive toy and told not to touch it for 30 s. Latency to touch the toy increased with age, and latent class growth modeling distinguished 2 groups of children that differed in their latencies to touch the toy at all 4 time points. Using confirmatory factor analysis, we decomposed the 3 EFs (measured with latent variables at age 17 years) into a Common EF factor (isomorphic to response inhibition ability) and 2 factors specific to updating and shifting. Less-restrained children had significantly lower scores on the Common EF factor, equivalent scores on the Updating-Specific factor, and higher scores on the Shifting-Specific factor than did the more-restrained children. The less-restrained group also had lower IQ scores, but this effect was entirely mediated by the EF components. Twin models indicated that the associations were primarily genetic in origin for the Common EF variable but split between genetics and nonshared environment for the Shifting-Specific variable. These results suggest a biological relation between individual differences in self-restraint and EFs, one that begins early in life and persists into late adolescence.     

An analysis of the internalizing and externalizing behaviors of traumatized urban youth with and without PTSD

To test the differential validity of the posttraumatic stress disorder (PTSD) classification, 3 groups of youths (PTSD, traumatized PTSD negatives, and controls) were examined. Youth with major comorbid disorders were excluded. On the basis of an analysis of parent-derived Child Behavior Checklist (CBCL) ratings, significant variations in CBCL scores were associated with PTSD but not with exposure to exceptional stress in the absence of PTSD. The results also indicated that traumatic exposure without the development of PTSD was not associated with higher estimates of psychopathology.     

Poly‐victimization and executive functions in junior college students

This study sought to characterize executive dysfunctions in poly‐victimized students without posttraumatic stress disorder (PTSD) symptoms and the relationship between neuropsychological and behavioral rating measures of executive functions (EFs). Based on self‐report data of exposure to victimization and PTSD symptoms, 259 junior college students aged 18–21 years were classified into four groups: poly‐victimization with PTSD symptoms (PVP), poly‐victimization without PTSD symptoms (PVnP), non‐poly‐victimization (nPV), and non‐victimization (nV). Respondents also completed the Behavior Rating Inventory of Executive Function‐Adult Version (BRIEF‐A). Of the 259 participants, 131 were administered a battery of neuropsychological tests from the Cambridge Neuropsychological Testing Automated Battery (CANTAB). The PVP group and the PVnP group performed worse than the nV group on most BRIEF‐A scales. When compared with the nPV group, the PVP group demonstrated poorer performance on the scales of Inhibit, Shift, Emotional Control, Initiate, and Working Memory, while the PVnP group performed more poorly on the Working Memory scale and the Task Monitor scale. For all BRIEF‐A scales, no significant differences were detected between the PVP group and the PVnP group. This study showed no between‐group differences for most of the neuropsychological tests except for the Stop Signal Task (SST), and no correlations between these two measures of EFs. Overall, we found evidence of an association between deficits in EFs and poly‐victimization. Although our study raises questions about the relationship between these two measures of EFs, it suggests that the use of the BRIEF‐A in conjunction with the CANTAB provides a more complete assessment of the executive dysfunctions.     

War trauma lingers on: Associations between maternal posttraumatic stress disorder,parent–child interaction,and child development

Maternal traumatization has been proposed as a risk factor for child development, but the mechanisms involved are poorly understood. This study analyzed the interrelations among maternal posttraumatic stress symptoms, parent–child interaction (emotional availability), and infants' psychosocial functioning and development among 49 asylum‐seeker and refugee mothers and their children (18–42 months). Measures included assessment of mothers' trauma and comorbid symptoms (Harvard Trauma Questionnaire: R.F. Mollica et al., 1992 ; Hopkins Symptom Checklist: L. Derogatis, R. Lipman, K. Rickels, E. Uhlenhuth, & L. Covi, 1974 ), emotional availability within parent–child interaction (Emotional Availability Scales: Z. Biringen, 2008 ), and infants' psychosocial functioning (Child Behavior Checklist: T.M. Achenbach & L.A. Rescorla, 2000 ) and development (Bayley Scales of Infant Development: B.F. van der Meulen, S.A.J. Ruiter, H.C. Spelberg, & M. Smrkovsky, 2000 ). The results show that higher levels of maternal posttraumatic stress symptoms are associated with a higher level of psychosocial problems of infants, but not with delays in their mental or psychomotor development. The results also show that higher levels of maternal posttraumatic stress symptoms are associated with higher levels of insensitive, unstructuring, or hostile, but not intrusive, parent–child interactions. Infants show lower levels of responsiveness and involvement to their traumatized mothers. Parent–child interaction did not function as a mediator between maternal trauma symptoms and infants' psychosocial functioning. Results are discussed in relation to the dyad's regulation of emotions. Results implicate a need to reestablish attunement between traumatized mothers and their nontraumatized children.     

The intellectual performance of traumatized children and adolescents with or without posttraumatic stress disorder

This study compared the Wechsler Intelligence Scale for Children-III (WISC-III) scores of traumatized youth with posttraumatic stress disorder (PTSD) to the scores of trauma-exposed and nonexposed comparison groups without PTSD. All groups were free of additional major childhood psychiatric disorders. The PTSD group scored significantly lower than the comparison groups on verbal subtests, but not on performance subtests. The scores of the trauma-exposed PTSD negatives and nontrauma exposed controls were not significantly different. Accordingly, PTSD and not a history of trauma exposure in the absence of PTSD was associated with lower verbal IQ.     

Attention Bias for Threatening Information in Children Following a Distressing Medical Procedure

Attention bias is common in adults with post‐traumatic stress disorder (PTSD) but is less studied in children. Children (n = 22) who experienced a potentially distressing procedure in an outpatient clinic (removal of K‐wires from orthopaedic fractures) and a group of medically unwell children (illness group; n = 27) were compared with healthy controls (n = 32). Children's baseline level of PTS symptoms were indexed prior to the medical procedure, and again at 1‐week follow‐up. Immediately after the K‐wire removal, children completed a dot probe task using two categories of target words (medical threatening and emotionally threatening). While K‐wire children showed an overall bias away from negative words relative to healthy controls, the illness group did not significantly differ from healthy controls. Attention bias in K‐wire and illness groups was unrelated to later PTS symptoms.     

Parental Guidance and Children's Executive Function: Working Memory and Planning as Moderators During Joint Problem‐Solving

Cognitive aspects of children's executive function (EF) were examined as moderators of the effectiveness of parental guidance on children's learning. Thirty‐two 5‐year‐old children and their parents were observed during joint problem‐solving. Forms of guidance geared towards cognitive assistance were coded as directive or elaborative, and children's responses were recorded. Children were then assessed on an independent version of the same task. A parent‐rated composite of working memory and planning was used as a measure of EF. Directive guidance by parents was associated with more child errors during the joint activity, whereas elaborative guidance was associated with better performance. Parent‐rated EF moderated the relation, such that the relation between elaborative guidance and better performance was only significant for children with low EF. During the independent task, EF again moderated the relation between parent guidance and children's performance, such that children with low EF did worse when parents had provided more directive guidance; for children with high EF, directive guidance was associated with better independent performance. These findings suggest that the extent to which children's performance relates to different forms of parents' guidance varies, and elaborative assistance may be more helpful for children with low EF. Copyright © 2016 John Wiley & Sons, Ltd.     

Inhibition and working memory in young preschool children with symptoms of ADHD and/or oppositional-defiant disorder

Background: Early symptoms of attention deficit/hyperactivity disorder (ADHD) and oppositional-defiant disorder (ODD) are associated with deficits in cognitive self-regulatory processes or executive functions (EF)s. However, the hypothesis that neurocognitive deficits underlying the two disorders are already evident during early preschool years still has limited empirical support. The present study investigated associations between symptoms of ADHD and/or ODD and two core EFs, inhibition and working memory, in a large nonclinical sample of 3-year old children. Method: Participants were 1045 children (554 boys, age 37–47 months), recruited from the population based Norwegian Mother and Child Cohort Study (MoBa). Relations between behavioral symptoms and measures of inhibition and working memory were studied both categorically and dimensionally. Results: Children with co-occurring symptoms of ADHD and ODD performed at a significantly lower level than typically developing children in 4 out of 5 EF measures. Symptoms of ADHD, both alone and in combination with ODD, were associated with reduced performance on tests of inhibition in the group comparisons. Dimensional analyses showed that performance within both EF domains contributed to variance primarily in ADHD symptom load. The associations between test results and behavioral symptoms remained significant after gender and verbal skills had been controlled. Conclusion: Young preschoolers show the same pattern of relations between EF and behavioral symptoms of ADHD and/or ODD as previously described in older children diagnosed with ADHD and/or ODD. Effect sizes were generally small, indicating that measures of EF have limited clinical utility at this stage in development.     

Development of norms for executive functions in typically-developing Indian urban preschool children and its association with nutritional status

Executive functions (EFs) are essential and important for achieving success in children’s everyday lives and play a fundamental role in children’s cognitive, academic, social, emotional and behavioral functioning. A cross-sectional study was carried out to develop age- and sex-specific norms for EFs using the Behavior Rating Inventory of Executive Function – Preschool Version (BRIEF-P) among 2- to 5-year-olds from urban Bangalore, India. In addition, the association between EFs and anthropometric measures, a marker of nutritional status, is also examined. Primary caregivers of 412 children, equally distributed by age and sex, participated. Raw scores for each domain and indices were converted to standard t-scores and percentiles were computed. A t-score at or above 63 corresponding to the 90th percentile was considered as the cutoff for executive dysfunction in this sample. The prevalence of executive dysfunction is 10% based on the Global Executive Composite score of the BRIEF-P. The cutoff score for identifying executive dysfunction using existing United States (US) norms is higher compared to the cutoff score obtained in the current study. Therefore, using US norms for Indian children could result in the prevalence of executive dysfunction been underestimated. Multiple linear regression analysis revealed that stunted and underweight children have significantly elevated EF scores after adjusting for age, sex and socioeconomic status (SES; p < .01). A greater understanding of EFs in preschool children is important for the early identification of executive dysfunction and implementing interventions to improve their future prospects. This study also shows that undernourished children are more likely to have executive dysfunction.     

Executive function in paediatric medulloblastoma: The role of cerebrocerebellar connections

Executive functions (EFs) are involved in the attainment, maintenance, and integration of information; these functions may play a key role in cognitive and behavioural outcomes in children treated for medulloblastoma (MB). At present, it remains unclear which EFs are most sensitive to the treatment effects for MB and whether damage to cerebrocerebellar circuitry is associated with EF. We completed a comprehensive evaluation of EF in 24 children treated for MB and 20 age‐matched healthy children (HC) and distilled these measures into components. Six components (C1–C6) were extracted from our model, reflecting dissociable constructs of EF: C1 = cognitive efficiency; C2 = planning/problem‐solving; C3 = positive cognitive emotion regulation; C4 = working memory; C5 = negative cognitive emotion regulation; and C6 = mixed cognitive emotion regulation. Group differences were found for C1, C2, C3, and C4; the MB group showed poorer performance on EF tasks and made less use of positive cognitive emotion regulation strategies relative to HC. Compromise to cerebrocerebellar microstructure – cerebro‐ponto‐cerebellar and cerebello‐thalamo‐cerebral pathways – was evident in children treated for MB compared to HC. We found that cerebrocerebellar circuitry has a mediating effect on one component of EF following treatment for MB – working memory.