Theory of mind in children with traumatic brain injury

Measuring mindreading in preschoolers: The perspective battery (PERBAT)

OBJECTIVE

The capacity to take another person's visual perspective is pivotal for solving mindreading tests, such as Theory of Mind (ToM) tasks, but most of them heavily rely on domain-general abilities (e.g., language, executive functions). Here we present a novel battery of visual perspective-taking tests for child neuropsychological assessment, the Perspective Battery (PERBAT), which poses a limited load on domain-general abilities.

METHODS

The battery includes four tests: i) Block Building; ii) Hide and Seek; iii) Deceptive Figures; iv) Double-Sided Shelf. We administered the PERBAT to 126 typically developing preschoolers (65 males; 3-6-year-old); the participants also performed classical tests of social cognition, language, and nonverbal abstract reasoning.

RESULTS

The scores of all the PERBAT tests were significantly and positively related with age and scores of the classical social cognition tests, but not with scores of the language and nonverbal abstract reasoning tests.

CONCLUSIONS

The PERBAT could represent a useful neuropsychological tool providing a comprehensive assessment of visual perspective-taking skills in preschool children. Future investigation is needed to examine the validity of the PERBAT with neurotypical samples across countries, race, ethnicity, and language as well as with clinical populations. Longitudinal studies are also encouraged to examine whether early visual perspective-taking weaknesses are associated with later development of mindreading skills.

Regional Cortical Thickness Correlates of Intellectual Abilities Differ in Children With Traumatic Brain Injury Versus Those With Orthopedic Injury in the Chronic Post-Injury Phase

A decline in intellectual functioning (intelligence quotient [IQ]) is often observed following more severe forms of traumatic brain injury (TBI) and is a useful index for long-term outcome. Identifying brain correlates of IQ can serve to inform developmental trajectories of behavior in this population. Using magnetic resonance imaging (MRI), we examined the relationship between intellectual abilities and patterns of cortical thickness in children with a history of TBI or with orthopedic injury (OI) in the chronic phase of injury recovery. Participants were 47 children with OI and 58 children with TBI, with TBI severity ranging from complicated-mild to severe. Ages ranged from 8 to 14 years old, with an average age of 10.47 years, and an injury-to-test range of ∼1-5 years. The groups did not differ in age or sex. The intellectual ability estimate (full-scale [FS]IQ-2) was derived from a two-form (Vocabulary and Matrix Reasoning subtests) Wechsler Abbreviated Scale of Intelligence (WASI). MRI data were processed using the FreeSurfer toolkit and harmonized across data collection sites using neuroComBat procedures, while holding demographic features (i.e., sex, socioeconomic status [SES]), TBI status, and FSIQ-2 constant. Separate general linear models per group (TBI and OI) and a single interaction model with all participants were conducted with all significant results withstanding correction for multiple comparisons via permutation testing. Intellectual ability was higher (p < 0.001) in the OI group (FSIQ-2 = 110.81) than in the TBI group (FSIQ-2 = 99.81). In children with OI, bi-hemispheric regions, including the right pre-central gyrus and precuneus and bilateral inferior temporal and left occipital areas were related to IQ, such that higher IQ was associated with thicker cortex in these regions. In contrast, only cortical thickness in the right pre-central gyrus and bilateral cuneus positively related to IQ in children with TBI. Significant interaction effects were found in the bilateral temporal, parietal, and occipital lobes and left frontal regions, indicating that the relationship between IQ and cortical thickness differed between groups in these regions. Changes in cortical associations with IQ after TBI may reflect direct injury effects and/or adaptation in cortical structure and intellectual functioning, particularly in the bilateral posterior parietal and inferior temporal regions. This suggests that the substrates of intellectual ability are particularly susceptible to acquired injury in the integrative association cortex. Longitudinal work is needed to account for normal developmental changes and to investigate how cortical thickness and intellectual functioning and their association change over time following TBI. Improved understanding of how TBI-related cortical thickness alterations relate to cognitive outcome could lead to improved predictions of outcome following brain injury.

Effectiveness of training in expressing positive emotions, reacting to change and greeting peers after childhood traumatic brain injury: a single-case experimental study

Background

Social cognitive deficits are common after traumatic brain injury (TBI). The participant in this single-case experimental design (SCED) was 7 years old when he sustained a severe TBI. After 2 years in rehabilitation, he continues to show deficits in social cognition.

Objective

To determine the effectiveness of three interventions, each aimed at improving a behavior altered by social cognition deficits. These behaviors were: (1) expression of positive emotions, (2) reacting to changes in plans, and (3) greeting classmates.

Method

An A-B-A' design was used for each behavior. In addition, each behavior was targeted with a rehabilitation program applied over 10 sessions.

Results

For the first behavior, changes between phases B-A' (NAP = 0.712) and A-A' (NAP = 0.864) indicated improvements in the child's ability to express positive emotions. In the second behavior, changes in the intensity of reactions between phases B and A' (NAP = 0.815) and A vs. A' (NAP = 0.834) indicated that the child adapted to changes in a plan and to unexpected situations in a more adaptive way. For the third behavior, changes in the number of greetings between phases A and B (NAP = 0.883) and A vs. A' (NAP = 0.844) suggested that during the third phase of the study, the participant fully acquired the habit of greeting peers and increased his interactions with others.

Conclusion

While the participant showed improvements in all three targeted behaviors, due to the complexity of the third behavior, it is recommended that in future research, the intervention targeting social interactions should be applied over a longer timeframe to ensure that improvements are more stable in the long term.

Working Memory for Emotions in Adolescents and Young Adults with Traumatic Brain Injury

This preliminary study investigated the interaction between working memory and social cognition in adolescents and young adults with traumatic brain injury (TBI). It was hypothesized that participants with or without TBI would better recognize social information when working memory or social cognitive load was low, and that adolescents and young adults with TBI would be more affected by increased cognitive demand than their uninjured peers. Eight adolescents and young adults with complicated mild-severe TBI (aged 14-22 years) and eight age- and sex-matched typically developing (TD) adolescents completed computer-based n-back tasks requiring recognition of either face identity or facial affect, with 0-back, 1-, and 2-back conditions. The TBI group had lower scores overall than the TD group, and scores for both groups were lower for affect recognition than identity recognition. Scores for both groups were lower in conditions with a higher working memory load. There was a significant group-by-working memory interaction, with larger group differences in high-working memory conditions. Study results and their potential implications for social outcomes are discussed.

Social Functioning and Autistic Behaviors in Youth Following Acquired Brain Injury

Children and adolescents who survive the pediatric intensive care unit (PICU) with an acquired brain injury (ABI) often demonstrate a variety of physical, cognitive, emotional/behavioral, and social sequelae termed post-intensive care syndrome (PICS). Social communication and interaction challenges have also been observed clinically, and there is growing literature documenting these occurrences in youth following ABI. The extent of these social changes varies among patients, and a subset of patients go on to exhibit social and behavioral profiles closely resembling those of autistic youth. We reviewed empirical research regarding social functioning in youth following ABI, as well as the overlap between individuals with ABI and autistic youth, published from January 2009 to August 2022 on PubMed and Scopus databases. Clinical case examples from a well-established post-PICU follow-up program are also provided to exemplify the complexity of this phenomenon.

The Impact of Traumatic Injury to the Immature Human Brain: A Scoping Review with Insights from Advanced Structural Neuroimaging

Traumatic brain injury (TBI) during critical periods of early-life brain development can affect the normal formation of brain networks responsible for a range of complex social behaviors. Because of the protracted nature of brain and behavioral development, deficits in cognitive and socioaffective behaviors may not become evident until late adolescence and early adulthood, when such skills are expected to reach maturity. In addition, multiple pre- and post-injury factors can interact with the effects of early brain insult to influence long-term outcomes. In recent years, with advancements in magnetic-resonance-based neuroimaging techniques and analysis, studies of the pediatric population have revealed a link between neurobehavioral deficits, such as social dysfunction, with white matter damage. In this review, in which we focus on contributions from Australian researchers to the field, we have highlighted pioneering longitudinal studies in pediatric TBI, in relation to social deficits specifically. We also discuss the use of advanced neuroimaging and novel behavioral assays in animal models of TBI in the immature brain. Together, this research aims to understand the relationship between injury consequences and ongoing brain development after pediatric TBI, which promises to improve prediction of the behavioral deficits that emerge in the years subsequent to early-life injury.

Theory of Mind after Pediatric Traumatic Brain Injury: A Scoping Review

This scoping review aims to synthesize existing literature regarding theory of mind (ToM) outcomes, the neuropathology associated with ToM outcomes, and the relationship between ToM outcomes and social functioning in children and adolescents with traumatic brain injury (TBI). We searched MEDLINE^® and PsycINFO databases to identify all literature that examined ToM following pediatric TBI until July 2019. A total of 29 articles met inclusion and exclusion criteria and were included in the results. These articles examined a variety of aspects of ToM, which could be broadly grouped into those focused on cognitive, cognitive-affective, and pragmatic factors. The existing literature suggests that children and adolescents with TBI, compared with their typically developing peers and peers with orthopedic injuries, are more likely to have deficits in ToM. The evidence further shows that the age at which brain injury occurs contributes to ToM disruption. Neuroimaging techniques have offered crucial insights into how TBI may impact ToM performance in children and adolescents. Finally, this review provides evidence that disruption in ToM plays a role in the difficulties in social functioning demonstrated by children and adolescents with TBI. Limitations and gaps in the existing literature warrant future research in this field.

Friendships in Pediatric Brain Tumor Survivors and Non-Central Nervous System Tumor Survivors

OBJECTIVE

Brain tumors during childhood may disrupt the development and maintenance of friendships due to the impact of disease- and treatment-related factors on functioning. The goal of this study was to determine if children treated for either a brain tumor or a non-central nervous system (CNS) solid tumor could name a friend and to evaluate the social information processes associated with the ability to name a friend.

METHOD

Youth (ages 7-14) treated for either a brain tumor (n = 47; mean age = 10.51 years) or a non-CNS solid tumor (n = 34; mean age = 11.29) completed an assessment within 6 months of the conclusion of treatment that included asking participants to name a friend and completing measures of social information processing (SIP). Rates of self-reported friendship were compared between groups and correlates of being able to name a friend were evaluated.

RESULTS

Youth treated for a brain tumor (61.7%) were significantly less likely to name a friend compared with youth treated for a non-CNS solid tumor (85.3%). Diagnosis type (brain vs. non-CNS), relapse status, attribution style, and facial affect recognition were significant predictors of being able to name a friend or not in a logistic regression model.

CONCLUSIONS

Youth treated for a brain tumor and those who experienced a disease relapse are at risk for impairments in friendships; difficulties with SIP may increase this risk. Targeted screening and intervention efforts for children diagnosed with brain tumors and those who have relapsed could address difficulties with peers.

Delineating the Nature and Correlates of Social Dysfunction after Childhood Traumatic Brain Injury Using Common Data Elements: Evidence from an International Multi-Cohort Study

Although childhood traumatic brain injury (TBI) has been linked to heightened risk of impaired social skills and behavior, current evidence is weakened by small studies of variable methodological quality. To address these weaknesses, this international multi-cohort study involved synthesis of data from two large observational cohort studies of complicated mild-severe child TBI in Australia and North America. Both studies adopted a unified approach to data collection and coding procedures, providing the opportunity to merge datasets from multiple, well-characterized cohorts for which gold standard measures of social outcomes were collected during the chronic recovery phase. The study involved 218 children, including 33 children with severe TBI, 83 children with complicated mild-moderate TBI, 59 children with orthopedic injury, and 43 age- and sex-matched typically developing control children. All injured children were recruited from academic children's hospitals and underwent direct cognitive assessments including measures of theory of mind (ToM) at least 1-year post- injury. Parents rated their child's social adjustment using standardized measures of social skills, communication and behavior. Results showed a brain-injury specific effect on ToM abilities, such that children with both complicated mild to moderate and severe TBI displayed significantly poorer ToM than children without TBI. In mediator models, poorer ToM predicted poorer parent-rated self-direction and social skills, as well as more frequent behavioral symptoms. The ToM mediated the effect of severe TBI on parent ratings of communication and social skills, as well as on overall behavior symptoms. The findings suggest that deficits in ToM are evident across the spectrum of TBI severity and represent one mechanism linking severe child TBI to long-term social adjustment difficulties. The findings underscore the value of large-scale data harmonization projects to increase the quality of evidence regarding the outcomes of TBI. Clinical and scientific implications are discussed.

Assessment of White Matter Integrity after Pediatric Traumatic Brain Injury

White matter (WM) abnormalities, such as atrophy and hyperintensities (WMH), can be accessed via magnetic resonance imaging (MRI) after pediatric traumatic brain injury (TBI). Several methods are available to classify WM abnormalities (i.e., total WM volumes and WMHs), but automated and manual volumes and clinical ratings have yet to be compared in pediatric TBI. In addition, WM integrity has been associated reliably with processing speed. Consequently, methods of assessing WM integrity should relate to processing speed to have clinical application. This study had two goals: (1) to compare Scheltens rating scale, manual tracing, FreeSurfer, and NeuroQuant® methods of assessing WM abnormalities, and (2) to relate WM methods to processing speed scores. We report findings from the Social Outcomes of Brain Injury in Kids (SOBIK) study, a multi-center study of 60 children with chronic TBI (65% male) from ages 8-13. Scheltens WMH ratings had good to excellent agreement with WMH volumes for both NeuroQuant (ICC = 0.62; r = 0.29, p = 0.005) and manual tracing (ICC = 0.82; r = 0.50, p = 0.000). NeuroQuant WMH volumes did not correlate with manually traced WMH volumes (r = 0.12, p = 0.21) and had poor agreement (ICC = 0.24). NeuroQuant and FreeSurfer total WM volumes correlated (r = 0.38, p = 0.004) and had fair agreement (ICC = 0.52). The WMH assessment methods, both ratings and volumes, were associated with processing speed scores. In contrast, total WM volume was not related to processing speed. Measures of WMH may hold clinical utility for predicting cognitive functioning after pediatric TBI.

Altered Connectivity During a False-Belief Task in Adults With Autism Spectrum Disorder

BACKGROUND

Deficits in social communication are one of the main features of autism spectrum disorder (ASD). Adults with ASD show atypical brain activity during false-belief understanding, an aspect of social communication involving the ability to infer that an individual can have an incorrect belief about a situation. Our study is the first to investigate whether adults with ASD exhibit differences in frequency-specific functional connectivity patterns during false-belief reasoning.

METHODS

We used magnetoencephalography to contrast functional connectivity underlying false-belief understanding between 40 adults with ASD and 39 control adults. We examined whole-brain phase synchrony measures during a false-belief task in 3 frequency bands: theta (4-7 Hz), alpha (8-14 Hz), and beta (15-30 Hz).

RESULTS

Adults with ASD demonstrated reduced theta-band connectivity compared with control adults between several right-lateralized and midline regions such as the medial prefrontal cortex, right temporoparietal junction, right inferior frontal gyrus, and right superior temporal gyrus. During false-belief trials, they also recruited a network in the beta band that included primary visual regions such as the bilateral inferior occipital gyri and the left anterior temporoparietal junction.

CONCLUSIONS

Reduced theta-band synchrony between areas associated with mentalizing, inhibition, and visual processing implies some difficulty in communication among these functions in ASD. This impairment in top-down control in the theta band may be counterbalanced by their engagement of a beta-band network because both the left anterior temporoparietal junction and beta-band oscillations are associated with attentional processes. Thus, adults with ASD demonstrate alternative neural mechanisms for successful false-belief reasoning.

The mentalizing network and theory of mind mediate adjustment after childhood traumatic brain injury

Childhood traumatic brain injury (TBI) affects over 600 000 children per year in the United States. Following TBI, children are vulnerable to deficits in psychosocial adjustment and neurocognition, including social cognition, which persist long-term. They are also susceptible to direct and secondary damage to related brain networks. In this study, we examine whether brain morphometry of the mentalizing network (MN) and theory of mind (ToM; one component of social cognition) mediates the effects of TBI on adjustment. Children with severe TBI (n = 15, M_age = 10.32), complicated mild/moderate TBI (n = 30, M_age = 10.81) and orthopedic injury (OI; n = 42, M_age = 10.65) completed measures of ToM and executive function and underwent MRI; parents rated children’s psychosocial adjustment. Children with severe TBI demonstrated reduced right-hemisphere MN volume, and poorer ToM, vs children with OI. Ordinary least-squares path analysis indicated that right-hemisphere MN volume and ToM mediated the association between severe TBI and adjustment. Parallel analyses substituting the central executive network and executive function were not significant, suggesting some model specificity. Children at greatest risk of poor adjustment after TBI could be identified based in part on neuroimaging of social brain networks and assessment of social cognition and thereby more effectively allocate limited intervention resources.

Systematic Review and Inventory of Theory of Mind Measures for Young Children

Theory of mind (TOM), the ability to infer mental states to self and others, has been a pervasive research theme across many disciplines including developmental, educational, neuro-, and social psychology, social neuroscience and speech therapy. TOM abilities have been consistently linked to markers of social adaptation and have been shown to be affected in a broad range of clinical conditions. Despite the wealth and breadth of research dedicated to TOM, identifying appropriate assessment tools for young children remains challenging. This systematic review presents an inventory of TOM measures for children aged 0-5 years and provides details on their content and characteristics. Electronic databases (1983-2019) and 9 test publisher catalogs were systematically reviewed. In total, 220 measures, identified within 830 studies, were found to assess the understanding of seven categories of mental states and social situations: emotions, desires, intentions, percepts, knowledge, beliefs and mentalistic understanding of non-literal communication, and pertained to 39 types of TOM sub-abilities. Information on the measures' mode of presentation, number of items, scoring options, and target populations were extracted, and psychometric details are listed in summary tables. The results of the systematic review are summarized in a visual framework "Abilities in Theory of Mind Space" (ATOMS) which provides a new taxonomy of TOM sub-domains. This review highlights the remarkable variety of measures that have been created to assess TOM, but also the numerous methodological and psychometric challenges associated with developing and choosing appropriate measures, including issues related to the limited range of sub-abilities targeted, lack of standardization across studies and paucity of psychometric information provided.

Determinants of social behavior deficits and recovery after pediatric traumatic brain injury

Traumatic brain injury (TBI) during early childhood is associated with a particularly high risk of developing social behavior impairments, including deficits in social cognition that manifest as reduced social interactions, with profound consequences for the individuals' quality of life. A number of pre-injury, post-injury, and injury-related factors have been identified or hypothesized to determine the extent of social behavior problems after childhood TBI. These include variables associated with the individual themselves (e.g. age, genetics, the injury severity, and extent of white matter damage), proximal environmental factors (e.g. family functioning, parental mental health), and more distal environmental factors (e.g. socioeconomic status, access to resources). In this review, we synthesize the available evidence demonstrating which of these determinants influence risk versus resilience to social behavior deficits after pediatric TBI, drawing upon the available clinical and preclinical literature. Injury-related pathology in neuroanatomical regions associated with social cognition and behaviors will also be described, with a focus on findings from magnetic resonance imaging and diffusion tensor imaging. Finally, study limitations and suggested future directions are highlighted. In summary, while no single variable can alone accurately predict the manifestation of social behavior problems after TBI during early childhood, an increased understanding of how both injury and environmental factors can influence social outcomes provides a useful framework for the development of more effective rehabilitation strategies aiming to optimize recovery for young brain-injured patients.

Do you know what I'm thinking? Temporal and spatial brain activity during a theory-of-mind task in children with autism

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First MEG study of neural underpinnings of theory of mind differences in autism.

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Children with autism show decreased LTPJ activity from 300 to 375 and 425 to 500 ms.

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Children with autism also show increased RIFG activity from 325 to 375 ms.

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Co-incident lower LTPJ and higher RIFG activity implies compensatory use of RIFG.

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Executive functions may augment impaired theory of mind in autism.

The social impairments observed in children with autism spectrum disorder are thought to arise in part from deficits in theory of mind, the ability to understand other people’s thoughts and feelings. To determine the temporal-spatial dynamics of brain activity underlying these atypical theory-of-mind processes, we used magnetoencephalography to characterize the sequence of functional brain patterns (i.e. when and where) related to theory-of-mind reasoning in 19 high-functioning children with autism compared to 22 age- and sex-matched typically-developing children aged 8–12 during a false-belief (theory-of-mind) task. While task performance did not differ between the two groups, children with autism showed reduced activation in the left temporoparietal junction between 300–375 and 425–500 ms, as well as increased activation in the right inferior frontal gyrus from 325 to 375 ms compared to controls. The overlap in decreased temporoparietal junction activity and increased right inferior frontal gyrus activation from 325 to 375 ms suggests that in children with autism, the right inferior frontal gyrus may compensate for deficits in the temporoparietal junction, a neural theory-of-mind network hub. As the right inferior frontal gyrus is involved in inhibitory control, this finding suggests that children with autism rely on executive functions to bolster their false-belief understanding.

White matter microstructure predicts longitudinal social cognitive outcomes after paediatric traumatic brain injury: a diffusion tensor imaging study

BACKGROUND

Deficits in social cognition may be among the most profound and disabling sequelae of paediatric traumatic brain injury (TBI); however, the neuroanatomical correlates of longitudinal outcomes in this domain remain unexplored. This study aimed to characterize social cognitive outcomes longitudinally after paediatric TBI, and to evaluate the use of sub-acute diffusion tensor imaging (DTI) to predict these outcomes.

METHODS

The sample included 52 children with mild complex-severe TBI who were assessed on cognitive theory of mind (ToM), pragmatic language and affective ToM at 6- and 24-months post-injury. For comparison, 43 typically developing controls (TDCs) of similar age and sex were recruited. DTI data were acquired sub-acutely (mean = 5.5 weeks post-injury) in a subset of 65 children (TBI = 35; TDC = 30) to evaluate longitudinal prospective relationships between white matter microstructure assessed using Tract-Based Spatial Statistics and social cognitive outcomes.

RESULTS

Whole brain voxel-wise analysis revealed significantly higher mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) in the sub-acute TBI group compared with TDC, with differences observed predominantly in the splenium of the corpus callosum (sCC), sagittal stratum (SS), dorsal cingulum (DC), uncinate fasciculus (UF) and middle and superior cerebellar peduncles (MCP & SCP, respectively). Relative to TDCs, children with TBI showed poorer cognitive ToM, affective ToM and pragmatic language at 6-months post-insult, and those deficits were related to abnormal diffusivity of the sCC, SS, DC, UF, MCP and SCP. Moreover, children with TBI showed poorer affective ToM and pragmatic language at 24-months post-injury, and those outcomes were predicted by sub-acute alterations in diffusivity of the DC and MCP.

CONCLUSIONS

Abnormal microstructure within frontal-temporal, limbic and cerebro-cerebellar white matter may be a risk factor for long-term social difficulties observed in children with TBI. DTI may have potential to unlock early prognostic markers of long-term social outcomes.

Uncovering the neuroanatomical correlates of cognitive, affective and conative theory of mind in paediatric traumatic brain injury: a neural systems perspective

Deficits in theory of mind (ToM) are common after neurological insult acquired in the first and second decade of life, however the contribution of large-scale neural networks to ToM deficits in children with brain injury is unclear. Using paediatric traumatic brain injury (TBI) as a model, this study investigated the sub-acute effect of paediatric traumatic brain injury on grey-matter volume of three large-scale, domain-general brain networks (the Default Mode Network, DMN; the Central Executive Network, CEN; and the Salience Network, SN), as well as two domain-specific neural networks implicated in social-affective processes (the Cerebro-Cerebellar Mentalizing Network, CCMN and the Mirror Neuron/Empathy Network, MNEN). We also evaluated prospective structure-function relationships between these large-scale neural networks and cognitive, affective and conative ToM. 3D T1- weighted magnetic resonance imaging sequences were acquired sub-acutely in 137 children [TBI: n = 103; typically developing (TD) children: n = 34]. All children were assessed on measures of ToM at 24-months post-injury. Children with severe TBI showed sub-acute volumetric reductions in the CCMN, SN, MNEN, CEN and DMN, as well as reduced grey-matter volumes of several hub regions of these neural networks. Volumetric reductions in the CCMN and several of its hub regions, including the cerebellum, predicted poorer cognitive ToM. In contrast, poorer affective and conative ToM were predicted by volumetric reductions in the SN and MNEN, respectively. Overall, results suggest that cognitive, affective and conative ToM may be prospectively predicted by individual differences in structure of different neural systems-the CCMN, SN and MNEN, respectively. The prospective relationship between cerebellar volume and cognitive ToM outcomes is a novel finding in our paediatric brain injury sample and suggests that the cerebellum may play a role in the neural networks important for ToM. These findings are discussed in relation to neurocognitive models of ToM. We conclude that detection of sub-acute volumetric abnormalities of large-scale neural networks and their hub regions may aid in the early identification of children at risk for chronic social-cognitive impairment.

Neural correlates of "Theory of Mind" in very preterm born children

Very preterm (VPT) birth (<32 weeks' gestational age) has been implicated in social-cognitive deficits including Theory of Mind (ToM); the ability to attribute mental states to others and understand that those beliefs can differ from one's own or reality. The neural bases for ToM deficits in VPT born children have not been examined. We used magnetoencephalography (MEG) for its excellent spatial and temporal resolution to determine the neural underpinnings of ToM in 24 VPT and 24 full-term born (FT) children (7-13 years). VPT children performed more poorly on neuropsychological measures of ToM but not inhibition. In the MEG task, both FT children and VPT children recruited regions involved in false belief processing such as the rIFG (VPT: 275-350 ms, FT: 250-375 ms) and left inferior temporal gyrus (VPT: 375-450 ms, FT: 325-375 ms) and right fusiform gyrus (VPT: 150-200 ms, FT: 175-250 ms). The rIPL (included in the temporal-parietal junction) was recruited in FT children (475-575 ms) and the lTPJ in VPT children (500-575 ms). However, activations in all regions were reduced in the VPT compared to the FT group. We suggest that with increasing social-cognitive demands such as varying the type of scenarios in the standardized measure of ToM, reduced activations in the rIFG and TPJ in the VPT group may reflect the decreased performance. With access to both spatial and temporal information, we discuss the role of domain general and specific regions of the ToM network in both groups. Hum Brain Mapp 38:5577-5589, 2017. © 2017 Wiley Periodicals, Inc.

Moral Reasoning in Children with Focal Brain Insults to Frontotemporal Regions

Neuroscientific evidence indicates that human social functioning is supported by a distributed network of frontal and temporal brain regions that undergoes significant development during childhood and adolescence. Clinical studies of individuals with early brain insults (EBI) to frontotemporal regions suggest that such lesions may interfere with the maturation of sociocognitive skills and lead to increased sociobehavioural problems. However, little attention has focussed on the direct assessment of sociocognitive skills, such as moral reasoning, following focal EBI. In the present study, the performance of 15 patients with focal EBI (8–16 years) was compared to that of 15 demographically matched controls on basic neuropsychological measures (IQ and executive functions), sociocognitive tasks (moral reasoning, moral decision-making and empathy) and parent reports of sociobehavioural problems and social adaptive skills. Patients with focal EBI had significantly lower levels of moral reasoning maturity, moral decision-making, and empathy than their matched controls, but did not differ on more general measures of cognition. Their parents also reported increased sociobehavioural problems. These findings suggest that focal EBI to frontotemporal regions can result in reduced sociocognitive capacities, more specifically moral reasoning, and increased vulnerability to sociobehavioural problems.

Predictors of Long-Term Victimization After Early Pediatric Traumatic Brain Injury

OBJECTIVE

Pediatric traumatic brain injuries (TBIs) adversely affect long-term functional and social outcomes. Limited research suggests children with TBI are more likely to be victimized by peers than noninjured children. Deficits in social information processing (SIP), cognitive ability, and executive functioning (EF) may contribute to increased victimization risk. This study examined rates of peer victimization/bullying in children with early TBI compared with children with orthopedic injuries (OIs) and the role of processing speed, executive function (EF), and SIP as mediators of the association of TBI and peer victimization.

METHOD

Children ages 10 to 14 years who sustained a complicated mild/moderate or severe TBI (N = 58) or OI (N = 72) during early childhood (ages 3-7 yr) and their parents participated in a longitudinal prospective follow-up 6.8 years postinjury. SIP, EF and processing speed, and peer victimization were assessed.

RESULTS

Parents of children with severe TBI reported greater rates of peer victimization than parents of children with OIs. Children with severe TBI demonstrated greater EF deficits than children with complicated mild/moderate TBI or OI and poorer processing speed than children with OI. No significant indirect relationships were found between groups and any outcome variables to indicate mediation.

CONCLUSION

Based on parent report, children with severe TBI have higher risk of peer victimization than those with less severe injuries. In addition, children with severe TBI have more impaired EF and cognitive ability than counterparts with less severe TBI. Further research is needed to explore predictors of long-term victimization after early TBI to create interventions aimed at providing social, emotional, and behavioral skill building for victimized youth.

The Relation of Focal Lesions to Cortical Thickness in Pediatric Traumatic Brain Injury

In a sample of children with traumatic brain injury, this magnetic resonance imaging (MRI)-based investigation examined whether presence of a focal lesion uniquely influenced cortical thickness in any brain region. Specifically, the study explored the relation of cortical thickness to injury severity as measured by Glasgow Coma Scale score and length of stay, along with presence of encephalomalacia, focal white matter lesions or presence of hemosiderin deposition as a marker of shear injury. For comparison, a group of children without head injury but with orthopedic injury of similar age and sex were also examined. Both traumatic brain injury and orthopedic injury children had normally reduced cortical thickness with age, assumed to reflect neuronal pruning. However, the reductions observed within the traumatic brain injury sample were similar to those in the orthopedic injury group, suggesting that in this sample traumatic brain injury, per se, did not uniquely alter cortical thickness in any brain region at the group level. Injury severity in terms of Glasgow Coma Scale or longer length of stay was associated with greater reductions in frontal and occipitoparietal cortical thickness. However, presence of focal lesions were not related to unique changes in cortical thickness despite having a prominent distribution of lesions within frontotemporal regions among children with traumatic brain injury. Because focal lesions were highly heterogeneous, their association with cortical thickness and development appeared to be idiosyncratic, and not associated with group level effects.

Social dysfunction after pediatric traumatic brain injury: A translational perspective

Social dysfunction is common after traumatic brain injury (TBI), contributing to reduced quality of life for survivors. Factors which influence the development or persistence of social deficits after injury remain poorly understood, particularly in the context of ongoing brain maturation during childhood and adolescence. Aberrant social interactions have recently been modeled in adult and juvenile rodents after experimental TBI, providing an opportunity to gain new insights into the underlying neurobiology of these behaviors. Here, we review our current understanding of social dysfunction in both humans and rodent models of TBI, with a focus on brain injuries acquired during early development. Modulators of social outcomes are discussed, including injury-related and environmental risk and resilience factors. Disruption of social brain network connectivity and aberrant neuroendocrine function are identified as potential mechanisms of social impairments after pediatric TBI. Throughout, we highlight the overlap and disparities between outcome measures and findings from clinical and experimental approaches, and explore the translational potential of future research to prevent or ameliorate social dysfunction after childhood TBI.

Thinking about the thoughts of others; temporal and spatial neural activation during false belief reasoning

Theory of Mind (ToM) is the ability to understand the perspectives, mental states and beliefs of others in order to anticipate their behaviour and is therefore crucial to social interactions. Although fMRI has been widely used to establish the neural networks implicated in ToM, little is known about the timing of ToM-related brain activity. We used magnetoencephalography (MEG) to measure the neural processes underlying ToM, as MEG provides very accurate timing and excellent spatial localization of brain processes. We recorded MEG activity during a false belief task, a reliable measure of ToM, in twenty young adults (10 females). MEG data were recorded in a 151 sensor CTF system (MISL, Coquitlam, BC) and data were co-registered to each participant's MRI (Siemens 3T) for source reconstruction. We found stronger right temporoparietal junction (rTPJ) activations in the false belief condition from 150ms to 225ms, in the right precuneus from 275ms to 375ms, in the right inferior frontal gyrus from 200ms to 300ms and the superior frontal gyrus from 300ms to 400ms. Our findings extend the literature by demonstrating the timing and duration of neural activity in the main regions involved in the "mentalizing" network, showing that activations related to false belief in adults are predominantly right lateralized and onset around 100ms. The sensitivity of MEG will allow us to determine spatial and temporal differences in the brain processes in ToM in younger populations or those who demonstrate deficits in this ability.

Theory of mind mediates the prospective relationship between abnormal social brain network morphology and chronic behavior problems after pediatric traumatic brain injury

Childhood and adolescence coincide with rapid maturation and synaptic reorganization of distributed neural networks that underlie complex cognitive-affective behaviors. These regions, referred to collectively as the 'social brain network' (SBN) are commonly vulnerable to disruption from pediatric traumatic brain injury (TBI); however, the mechanisms that link morphological changes in the SBN to behavior problems in this population remain unclear. In 98 children and adolescents with mild to severe TBI, we acquired 3D T1-weighted MRIs at 2-8 weeks post-injury. For comparison, 33 typically developing controls of similar age, sex and education were scanned. All participants were assessed on measures of Theory of Mind (ToM) at 6 months post-injury and parents provided ratings of behavior problems at 24-months post-injury. Severe TBI was associated with volumetric reductions in the overall SBN package, as well as regional gray matter structural change in multiple component regions of the SBN. When compared with TD controls and children with milder injuries, the severe TBI group had significantly poorer ToM, which was associated with more frequent behavior problems and abnormal SBN morphology. Mediation analysis indicated that impaired theory of mind mediated the prospective relationship between abnormal SBN morphology and more frequent chronic behavior problems. Our findings suggest that sub-acute alterations in SBN morphology indirectly contribute to long-term behavior problems via their influence on ToM. Volumetric change in the SBN and its putative hub regions may represent useful imaging biomarkers for prediction of post-acute social cognitive impairment, which may in turn elevate risk for chronic behavior problems.

When Injury Clouds Understanding of Others: Theory of Mind after Mild TBI in Preschool Children

There is evidence to suggest that social skills, such as the ability to understand the perspective of others (theory of mind), may be affected by childhood traumatic brain injuries; however, studies to date have only considered moderate and severe traumatic brain injury (TBI). This study aimed to assess theory of mind after early, mild TBI (mTBI). Fifty-one children who sustained mTBI between 18 and 60 months were evaluated 6 months post-injury on emotion and desires reasoning and false-belief understanding tasks. Their results were compared to that of 50 typically developing children. The two groups did not differ on baseline characteristics, except for pre- and post-injury externalizing behavior. The mTBI group obtained poorer scores relative to controls on both the emotion and desires task and the false-belief understanding task, even after controlling for pre-injury externalizing behavior. No correlations were found between TBI injury characteristics and theory of mind. This is the first evidence that mTBI in preschool children is associated with theory of mind difficulties. Reduced perspective taking abilities could be linked with the social impairments that have been shown to arise following TBI.

Day of injury CT and late MRI findings: Cognitive outcome in a paediatric sample with complicated mild traumatic brain injury

OBJECTIVES

Complicated mild traumatic brain injury (mTBI) or cmTBI is based on the presence of visibly identifiable brain pathology on the day-of-injury computed tomography (CT) scan. In a paediatric sample the relation of DOI CT to late MRI findings and neuropsychological outcome was examined.

METHODS

MRI (>12 months) was obtained in paediatric cmTBI patients and a sample of orthopaedically injured (OI) children. Those children with positive imaging findings (MRI+) were quantitatively compared to those without (MRI-) or with the OI sample. Groups were also compared in neurocognitive outcome from WASI sub-tests and the WISC-IV Processing Speed Index (PSI), along with the Test of Everyday Attention for Children (TEA-Ch) and a parent-rated behavioural functioning measure (ABAS-II).

RESULTS

Despite the MRI+ group having significantly more DOI CT findings than the MRI- group, no quantitative differences were found. WASI Vocabulary and Matrix Reasoning scores were significantly lower, but not PSI, TEA-Ch or ABAS-II scores. MRI+ and MRI- groups did not differ on these measures.

CONCLUSIONS

Heterogeneity in the occurrence of MRI-identified focal pathology was not associated with uniform changes in quantitative analyses of brain structure in cmTBI. Increased number of DOI CT abnormalities was associated with lowered neuropsychological performance.

The emergence of age-dependent social cognitive deficits after generalized insult to the developing brain: a longitudinal prospective analysis using susceptibility-weighted imaging

Childhood and adolescence are critical periods for maturation of neurobiological processes that underlie complex social and emotional behavior including Theory of Mind (ToM). While structural correlates of ToM are well described in adults, less is known about the anatomical regions subsuming these skills in the developing brain or the impact of cerebral insult on the acquisition and establishment of high-level social cognitive skills. This study aimed to examine the differential influence of age-at-insult and brain pathology on ToM in a sample of children and adolescents with traumatic brain injury (TBI). Children and adolescents with TBI (n = 112) were categorized according to timing of brain insult: (i) middle childhood (5-9 years; n = 41); (ii) late childhood (10-11 years; n = 39); and (iii) adolescence (12-15 years; n = 32) and group-matched for age, gender, and socioeconomic status to a typically developing (TD) control group (n = 43). Participants underwent magnetic resonance imaging including a susceptibility-weighted imaging (SWI) sequence 2-8 weeks postinjury and were assessed on a battery of ToM tasks at 6- and 24-months after injury. Results showed that for adolescents with TBI, social cognitive dysfunction at 6- and 24-months postinjury was associated with diffuse neuropathology and a greater number of lesions detected using SWI. In the late childhood TBI group, we found a time-dependent emergence of social cognitive impairment, linked to diffuse neuropathology. The middle childhood TBI group demonstrated performance unrelated to SWI pathology and comparable to TD controls. Findings indicate that the full extent of social cognitive deficits may not be realized until the associated skills reach maturity. Evidence for brain structure-function relationships suggests that the integrity of an anatomically distributed network of brain regions and their connections is necessary for the acquisition and establishment of high-level social cognitive skills.

Functional plasticity in childhood brain disorders: when, what, how, and whom to assess

At every point in the lifespan, the brain balances malleable processes representing neural plasticity that promote change with homeostatic processes that promote stability. Whether a child develops typically or with brain injury, his or her neural and behavioral outcome is constructed through transactions between plastic and homeostatic processes and the environment. In clinical research with children in whom the developing brain has been malformed or injured, behavioral outcomes provide an index of the result of plasticity, homeostasis, and environmental transactions. When should we assess outcome in relation to age at brain insult, time since brain insult, and age of the child at testing? What should we measure? Functions involving reacting to the past and predicting the future, as well as social-affective skills, are important. How should we assess outcome? Information from performance variability, direct measures and informants, overt and covert measures, and laboratory and ecological measures should be considered. In whom are we assessing outcome? Assessment should be cognizant of individual differences in gene, socio-economic status (SES), parenting, nutrition, and interpersonal supports, which are moderators that interact with other factors influencing functional outcome.

Executive functions and theory of mind as predictors of social adjustment in childhood traumatic brain injury

This study examined whether executive function and theory of mind mediate the effects of pediatric traumatic brain injury (TBI) on social adjustment, relative to children with orthopedic injury (OI). Participants included 19 children with severe TBI, 41 children with complicated mild/moderate TBI, and 57 children with OI. They completed measures of executive function, as well as cognitive, affective, and conative theory of mind. Parents provided ratings of children's social adjustment. Children with severe TBI performed more poorly than children with OI on executive function and theory of mind tasks and were rated by parents as having more behavioral symptoms and worse communication and social skills. Executive function and theory of mind were positively correlated with social skills and communication skills, and negatively correlated with behavioral symptoms. In multiple mediator models, theory of mind and executive function were not significant direct predictors of any measure of social adjustment, but mediated the association between injury and adjustment for children with severe TBI. Theory of mind was a significant independent mediator when predicting social skills, but executive function was not. TBI in children, particularly severe injury, is associated with poor social adjustment. The impact of TBI on children's social adjustment is likely mediated by its effects on executive function and theory of mind.

Friendship quality and psychosocial outcomes among children with traumatic brain injury

This study examined differences in friendship quality between children with traumatic brain injury (TBI) and orthopedic injury (OI) and behavioral outcomes for children from both groups. Participants were 41 children with TBI and 43 children with OI (M age=10.4). Data were collected using peer- and teacher-reported measures of participants' social adjustment and parent-reported measures of children's post-injury behaviors. Participants and their mutually nominated best friends also completed a measure of the quality of their friendships. Children with TBI reported significantly more support and satisfaction in their friendships than children with OI. Children with TBI and their mutual best friend were more similar in their reports of friendship quality compared to children with OI and their mutual best friends. Additionally, for children with TBI who were rejected by peers, friendship support buffered against maladaptive psychosocial outcomes, and predicted skills related to social competence. Friendship satisfaction was related to higher teacher ratings of social skills for the TBI group only. Positive and supportive friendships play an important role for children with TBI, especially for those not accepted by peers. Such friendships may protect children with TBI who are rejected against maladaptive psychosocial outcomes, and promote skills related to social competence.

Cognitive, affective, and conative theory of mind (ToM) in children with traumatic brain injury

We studied three forms of dyadic communication involving theory of mind (ToM) in 82 children with traumatic brain injury (TBI) and 61 children with orthopedic injury (OI): Cognitive (concerned with false belief), Affective (concerned with expressing socially deceptive facial expressions), and Conative (concerned with influencing another's thoughts or feelings). We analyzed the pattern of brain lesions in the TBI group and conducted voxel-based morphometry for all participants in five large-scale functional brain networks, and related lesion and volumetric data to ToM outcomes. Children with TBI exhibited difficulty with Cognitive, Affective, and Conative ToM. The perturbation threshold for Cognitive ToM is higher than that for Affective and Conative ToM, in that Severe TBI disturbs Cognitive ToM but even Mild-Moderate TBI disrupt Affective and Conative ToM. Childhood TBI was associated with damage to all five large-scale brain networks. Lesions in the Mirror Neuron Empathy network predicted lower Conative ToM involving ironic criticism and empathic praise. Conative ToM was significantly and positively related to the package of Default Mode, Central Executive, and Mirror Neuron Empathy networks and, more specifically, to two hubs of the Default Mode Network, the posterior cingulate/retrosplenial cortex and the hippocampal formation, including entorhinal cortex and parahippocampal cortex.

Social competence at 6 months following childhood traumatic brain injury

Children with traumatic brain injury (TBI) are at risk for social impairment. This study aimed to examine social function at 6 months post-TBI and to explore the contribution of injury, cognitive, and environmental influences. The sample included 136 children, 93 survivors of TBI, and 43 healthy controls. TBI participants were recruited on admission and underwent magnetic resonance imaging scan within 8 weeks of injury and behavioral assessment at 6 months post-injury. Healthy controls underwent magnetic resonance imaging scans and behavioral assessment on recruitment. Assessment included parent and child questionnaires tapping social outcome and child-direct testing of cognitive abilities important for social competence (communication, attention/executive function, social cognition). Injury characteristics and environmental measures were collected. At 6-months post-injury, social problems were evident, but not global. Social participation appeared most vulnerable, with more severe injuries leading to greater problems. Greater injury severity and poorer communication skills were associated with poorer social adjustment and social participation, with the impact of family function also significant. Processing speed, younger age, and male gender also contributed to social outcomes. Further follow-up is required to track the recovery of social skills and the changing influences of cognition, brain, and environment over time.

Peer relationships of children with traumatic brain injury

This study examined peer relationships in children with traumatic brain injury (TBI) relative to children with orthopedic injuries (OI), and explored whether differences in peer relationships correlated with white matter volumes. Classroom procedures were used to elicit peer perceptions of social behavior, acceptance, and friendships for eighty-seven 8- to 13-year-old children, 15 with severe TBI, 40 with complicated mild/moderate TBI, and 32 with OI. Magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) were used to investigate volumetric correlates of peer relationship measures. Children with severe TBI were rated higher in rejection-victimization than children with OI, and were less likely than children with OI to have a mutual friendship in their classroom (47% vs. 88%). Children with TBI without a mutual friend were rated lower than those with a mutual friend on sociability-popularity and prosocial behavior and higher on rejection-victimization, and had lower peer acceptance ratings. Mutual friendship ratings were related to white matter volumes in several posterior brain regions, but not to overall brain atrophy. Severe TBI in children is associated with detrimental peer relationships that are related to focal volumetric reductions in white matter within regions of the brain involved in social information-processing.