Vicki Anderson

Development of Executive Functions Through Late Childhood and Adolescence in an Australian Sample

Although there have been significant theoretical advances in the field of child neuropsychology, developmental features of adolescence have received less attention. Progress in clinical practice is restricted due to a lack of well-standardized, developmentally appropriate assessment techniques. This article addresses these issues in relation to executive skills. These abilities are targeted for 2 reasons: first, because they are often considered to be mature during late childhood and adolescence, despite limited investigation in this age range; and second, because of their central importance to efficient day-to-day functioning. Using a normative sample of 138 children, aged 11.0 to 17.11 years, this article plots the development of executive skills through late childhood and early adolescence and interprets progress in these skills with reference to current neurological and cognitive theory.

Normative Data From the Cantab. I: Development of Executive Function Over the Lifespan

The study of executive function within a developmental framework has proven integral to the advancement of knowledge concerning the acquisition and decline of higher skill processes. Still in its early stages, there exists a discontinuity in the literature between the exploration of executive capacity in young children and the elderly. Research of age-related differences utilising a lifespan approach has been restricted by the lack of assessment tools for the measurement of executive skills that are applicable across all age levels. This paper addresses these issues using the computer-based Cambridge Neuropsychological Test Automated Battery (CANTAB) to identify periods of development in executive capacities using a normative sample of 194 participants ranging in age from 8 to 64 years. Findings of executive function in children as young as 8 years of age were extended, with functional gains found in the efficiency of working memory capacity, planning and problem-solving abilities, between the ages of 15 and 19 years and again at 20–29 years of age. Cognitive flexibility was assessed at adult-levels in even the youngest children. Declines in performance on all tasks were revealed for the 50–64 year old sample, providing support for the vulnerability of executive skills to normal aging.

Functional plasticity or vulnerability after early brain injury

Context. Traumatic brain injury (TBI) is a common, acquired, childhood disability that may be used as a model to understand more completely the impact of early brain injury on both brain structure and day-to-day function. Contrary to previously held views of the “plasticity” of the young brain, recent research suggests that such early insults may have a profound impact on development. To date, these suggestions remain largely untested. Objectives. To plot changes in cognitive abilities after childhood TBI over the 30 months after injury and to examine the impact of age at injury on cognitive outcomes. Design. Prospective longitudinal study. Setting. Royal Children’s Hospital, Victoria, Australia. Main Outcome Measures. Global intellectual ability, verbal and nonverbal skills, attention, and processing speed. Participants. A total of 122 children admitted to the hospital with a diagnosis of TBI were divided according to injury age, ie, young (age: 3–7 years) or old (age: 8–12 years), and injury severity (mild, moderate, or severe) and were evaluated acutely and at 12 and 30 months after injury. An additional sample of children injured before 3 years of age (n = 27) was compared with these groups with respect to global intellectual ability only. Results. A clear relationship was documented between injury severity and cognitive performance. For children who sustained severe injury, younger age at injury was associated with minimal, if any, recovery after injury, but better outcomes were observed after severe TBI among older children. Age at injury was not predictive of outcomes for children with mild or moderate TBI, although infants (age: 0–2.11 years) with moderate TBI showed poorer outcomes than did older children with injury of similar severity. Conclusions. Findings support a “double-hazard” model for severe and early brain insults and add to the ongoing debate regarding cerebral plasticity, suggesting that, contrary to traditional views, young children who sustain severe TBI in early childhood or moderate or severe TBI in infancy may be particularly vulnerable to significant residual cognitive impairment. From a clinical perspective, results indicate that long-term follow-up monitoring and management should be targeted to this high-risk group.

Relationships between cognitive and behavioral measures of executive function in children with brain disease.

This study addressed the clinical and construct validity of the Behavior Rating Inventory of Executive Function. (BRIEF: Gioia, Isquith, Guy, & Kenworthy, 2000), a questionnaire designed to tap behavioral aspects of executive functions in children. BRIEF profiles in early treated phenylketonuria (PKU; n = 44), early treated hydrocephalus (n = 45), frontal focal lesions (n = 20) and controls (n = 80) were examined. Clinical validity was supported through significant between-group comparisons, especially between the frontal focal lesion group and other groups. To examine construct validity, raw scores on cognitive executive function measures including the Contingency Naming Test (CNT), Rey Complex Figure (RCF), Tower of London (TOL), and Controlled Oral Word Association Test (COWAT), were correlated with BRIEF scale scores. Few significant correlations were found, indicating cognitive and behavioral measures appear to tap different constructs within the executive function domain. A dissociation was found between behavioral and cognitive impairments in the frontal as opposed to PKU and hydrocephalus groups. This is discussed in relation to underlying pathology, the cognitive measures used, and possible limitations in the BRIEFs usefulness for measuring behavioral executive dysfunction in groups only mildly affected by neurological compromise.

Assessing Executive Functions in Children: Biological, Psychological, and Developmental Considerations

Keywords Executive function, children, development, assessment Summary Executive functions may be de®ned as those skills necessary for purposeful, goal-directed activity, and are generally considered to be largely mediated by the frontal and prefrontal cortices of the brain. These cerebral regions are relatively immature during childhood, with development thought to be a protracted process which continues into early adolescence. While early theorists suggested that executive skills were not functional until cerebral maturity, recent research provides evidence that such skills can be elicited in early childhood. The aim of this paper is to review current theories of development of executive functions throughout childhood. In keeping with contemporary approaches to child neuropsychology, three critical dimensions will be evaluated; biological factors, psychological dimensions, and developmental trajectories. In addition, the literature which addresses assessment of these functions will be examined, with reference to developmental trajectories observed in normal populations, and in brain-damaged samples, where there may be disruption to the underlying neural substrates thought to be subsuming these functions.

SOCIAL: An Integrative Framework for the Development of Social Skills.

Despite significant advances in the field of social neuroscience, much remains to be understood regarding the development and maintenance of social skills across the life span. Few comprehensive models exist that integrate multidisciplinary perspectives and explain the multitude of factors that influence the emergence and expression of social skills. Here, a developmental biopsychosocial model (SOCIAL) is offered that incorporates the biological underpinnings and socio-cognitive skills that underlie social function (attention/executive function, communication, socio-emotional skills), as well as the internal and external (environmental) factors that mediate these skills. The components of the model are discussed in the context of the social brain network and are supported by evidence from 3 conditions known to affect social functioning (autism spectrum disorders, schizophrenia, and traumatic brain injury). This integrative model is intended to provide a theoretical structure for understanding the origins of social dysfunction and the factors that influence the emergence of social skills through childhood and adolescence in both healthy and clinical populations.

Twelve year outcomes following bacterial meningitis: further evidence for persisting effects

AIM To determine whether intellectual and cognitive impairments observed seven years following early childhood bacterial meningitis persist into adolescence. METHODS Blinded neuropsychological, auditory, and behaviour assessments were conducted in 109 (69%) subjects from an original cohort of 158 children, seven and 12 years after their meningitis, and in 96 controls. RESULTS Meningitis subjects remained at greater risk than controls for any disability (odds ratio OR 4.7, confidence interval 2.2 to 9.6). Those with acute neurological complications had more sequelae than children with uncomplicated meningitis or controls (47% v 30%v 11.5% respectively; p < 0.001). Differences in intellectual, academic, and high level cognitive function between subjects and controls were maintained at the seven and 12 year assessments. In contrast, lower order skills improved, while behaviour scores deteriorated significantly (p = 0.033). CONCLUSIONS Many of the deficits identified at the seven year follow up persist 12 years after an episode of bacterial meningitis. Key messages Bacterial meningitis in children is associated with substantial excess risk of intellectual, cognitive, and auditory impairment that persists into adolescence Continuing developmental problems of higher order language, organisation, problem solving, and central auditory function may increase learning and behavioural difficulties The risk of these adverse outcomes is greatest in, but not confined to, those who experienced acute neurological complications at the time of their illness Families, schoolteachers, and health professionals have an important role in identifying and/or helping those with learning and behavioural difficulties

Age at injury as a predictor of outcome following pediatric head injury: A longitudinal perspective

Abstract This study investigates the relationship between age at injury and recovery following pediatric head injury. Two groups were investigated: (1) children injured before age 7 (n = 16); (2) children injured at or after age 7 (n = 20). Groups were matched for socioeconomic status and injury severity. Using standardized intellectual measures, children were evaluated at 4 months and 2 years post head injury. Results revealed that children who sustained head injury prior to 7 years of age performed more poorly than did those injured at or after age 7, and that recovery profiles following head injury were associated with age at injury. Children who sustained head injuries in early childhood failed to exhibit the expected acute recovery pattern and maintained a stable performance from 4 months to 2 years postinjury. Children injured later in childhood showed recovery consistent with that described in adult head injury, with increases in performance between initial and follow-up assessments.

Can we manage sport related concussion in children the same as in adults

Evidence based guidelines are required for the management of concussive injury in children Consensus guidelines for managing sport related concussion in adults have been increasingly widely implemented.1 So far, there are no guidelines that enable clinicians to manage similar sporting concussive injuries in children. Furthermore, there are a number of important anatomical, physiological, and behavioural differences between adults and children that suggest that adult guidelines will need to be either modified or rewritten to manage injuries in this age group. The annual incidence of traumatic brain injury (TBI) in adults is remarkably constant worldwide and has been estimated at between 180 and 300 cases per 100 000 population.2–5 This is believed to be an underestimate of the true incidence as an equivalent number of mild injuries are treated by general practitioners and do not result in hospital admission.6 Direct sport participation accounts for approximately 15–20% of all such TBI3,7 and in children a further smaller percentage of TBI is associated with play activities.8 In children aged 15 years and under, the estimated incidence rate of TBI is 180 per 100 000 children per year of which approximately 85% are categorised as mild injuries.7 In the US, it has been estimated that more than 1 million children sustain a TBI annually and that TBI accounts for more than 250 000 paediatric hospital admissions as well as more than 10% of all visits to emergency service settings.9 In child and adolescent populations, few well controlled studies exist to identify the age specific frequency and outcome of sport related concussive injuries. The most common cognitive sequelae of concussive injuries in children are the same as for adults, namely reduced speed of information processing, poor attention, and impaired executive function.10–14 Concussion may also have a significant …

Childhood brain insult: can age at insult help us predict outcome?

Until recently, the impact of early brain insult (EBI) has been considered to be less significant than for later brain injuries, consistent with the notion that the young brain is more flexible and able to reorganize in the context of brain insult. This study aimed to evaluate this notion by comparing cognitive and behavioural outcomes for children sustaining EBI at different times from gestation to late childhood. Children with focal brain insults were categorized according to timing of brain insult, represented by six developmental periods: (i) Congenital (n = 38): EBI: first-second trimester; (ii) Perinatal (n = 33); EBI: third trimester to 1 month post-natal; (iii) Infancy (n = 23): EBI: 2 months-2 years post-birth; (iv) Preschool (n = 19): EBI: 3-6 years; (v) Middle Childhood (n = 31): EBI: 7-9 years; and (vi) Late Childhood (n = 19): EBI: after age 10. Groups were similar with respect to injury and demographic factors. Children were assessed for intelligence, academic ability, everyday executive function and behaviour. Results showed that children with EBI were at increased risk for impairment in all domains assessed. Furthermore, children sustaining EBI before age 2 years recorded global and significant cognitive deficits, while children with later EBI performed closer to normal expectations, suggesting a linear association between age at insult and outcome. In contrast, for behaviour, children with EBI from 7 to 9 years performed worse than those with EBI from 3 to 6 years, and more like those with younger insults, suggesting that not all functions share the same pattern of vulnerability with respect to age at insult.