Tara McAuley

Is the behavior rating inventory of executive function more strongly associated with measures of impairment or executive function

The Behavior Rating Inventory of Executive Function (BRIEF) is commonly used in the assessment of children and adolescents presenting with a wide range of concerns. It is unclear, however, whether the questionnaire is more closely related to general measures of behavioral disruption and impairment or to specific measures of executive function. In the present study, associations between the Behavioral Regulation Index and Metacognition Index of the BRIEF and cognitive, behavioral, and academic measures were examined in a sample of clinic-referred youth (n = 60) and healthy youth (n = 37) 6-15 years of age. Measures included ratings of inattentive and hyperactive-impulsive symptoms in youth, ratings of how well youth functioned in their everyday environments, youths scores on measures of reading and math, and youths scores on measures of inhibition, performance monitoring, and working memory. Although both BRIEF indices were strongly related to parent and teacher ratings of behavioral disruption and impairment, neither was associated with youths scores on the performance-based tasks of executive function. These findings support the use of the BRIEF as a clinical tool for assessing a broad range of concerns, but raise questions about the relation of the BRIEF to performance-based tasks that are commonly used to assess executive function.

A latent variables examination of processing speed, response inhibition, and working memory during typical development.

This study addressed three related aims: (a) to replicate and extend previous work regarding the nonunitary nature of processing speed, response inhibition, and working memory during development; (b) to quantify the rate at which processing speed, response inhibition, and working memory develop and the extent to which the development of these latter abilities reflect general changes in processing speed; and (c) to evaluate whether commonly used tasks of processing speed, response inhibition, and working memory are valid and reliable when used with a developmentally diverse group. To address these aims, a latent variables approach was used to analyze data from 147 participants 6-24years of age. Results showed that processing speed, response inhibition, and working memory were separable abilities and that the extent of this separability was stable across the age range of participants. All three constructs improved as a function of age; however, only the effect of age on working memory remained significant after processing speed was controlled. The psychometric properties of tasks used to assess the constructs were age invariant, thereby validating their use in studies of executive development.

The Persistence of Cognitive Deficits in Remitted and Unremitted ADHD: A Case for the State-Independence of Response Inhibition.

Background Response inhibition, working memory, and response variability are possible endophenotypes of ADHD based on their association with the disorder and evidence of heritability. One of the critical although rarely studied criteria for a valid endophenotype is that it persists despite waxing and waning of the overt manifestations of the disorder, a criterion known as state-independence. This study examined whether these aspects of cognition exhibit state-independence in ADHD. Methods One hundred and seventy-nine children diagnosed with ADHD in a rigorous baseline assessment were contacted for follow-up assessment in adolescence. Of this sample, 130 (73%) were reascertained. At follow-up, children previously diagnosed with ADHD were identified as remittent (n = 24), persistent (n = 64), or in partial remission (n = 42) based on symptoms and impairment of the disorder. Response inhibition, working memory, and response variability were assessed both in childhood (baseline) and adolescence (follow-up) and were compared with age-matched controls (40 children and 28 adolescents) seen at either time point. Results Relative to controls, ADHD children showed baseline deficits in response inhibition, working memory, and response variability. Only the group difference in response inhibition remained significant in adolescence. In general, cognitive performance among ADHD participants improved with age and did so regardless of changes in ADHD symptoms and impairment. Within the ADHD group, however, cognitive performance in childhood and in adolescence did not differ amongst those with persistent, remittent, and partially remittent forms of the disorder. Conclusions Results demonstrate that response inhibition not only distinguishes ADHD children from their unaffected peers but is also state-independent, such that deficits remain present irrespective of changes in the disease phenotype. In other words, inhibitory deficits measured in childhood persist into adolescence even when the ADHD phenotype remits. These findings provide further evidence that the ability to stop prepotent actions is an endophenotype of ADHD.

Revisiting inhibitory control across the life span: insights from the ex-Gaussian distribution.

Changes in inhibitory control occur across the life span and have been associated with alterations in prefrontal function. In this study, ex-Gaussian analysis was used to reexamine data from an inhibitory control task. Participants (ages 6 to 82 years) composed three groups: children, young adults, and older adults. In fitting the ex-Gaussian distribution to reaction time data, estimates of three parameters were obtained: mu (μ), reflecting average performance; sigma (σ), reflecting variability in performance; and tau (τ), reflecting extremes in performance. Older adults differed from young adults in terms of mu, sigma, and tau. For children, mu and tau values were comparable to those of young adults; sigma, however, was different. Thus, inhibitory changes in older adults were due to slower, more variable, and more extreme responding. Inhibitory changes in children were due only to more variable responding. These findings suggest that different mechanisms underlie age-related changes in inhibitory control during different epochs of the life span. This study demonstrates that the ex-Gaussian approach provides a finer level of analysis than data analytic approaches typically used in neuropsychological research.

Mapping the Development of Response Inhibition in Young Children Using a Modified Day-Night Task

Response inhibition was examined in 40 children 3½ to 8 years of age using a modified day-night task. Performance in a neutral condition explained variance in congruent and incongruent conditions, indicating that age-related improvements in these latter conditions were partly mediated by working memory and processing speed. After controlling for neutral performance, age did not explain variance in congruent performance but explained variance in incongruent performance. These findings indicate that the associative strength between pictures and labels used in the task is age invariant and that older children are better than younger children at inhibiting responses to these associations.

Performance on an episodic encoding task yields further insight into functional brain development.

To further characterize changes in functional brain development that are associated with the emergence of cognitive control, participants 14 to 28 years of age were scanned while performing an episodic encoding task with a levels-of-processing manipulation. Using data from the 12 youngest and oldest participants (endpoint groups), 18 regions were identified that showed group differences in task-related activity as a function of processing depth. One region, located in left inferior frontal gyrus, showed enhanced activity in deep relative to shallow encoding that was larger in magnitude for the older group. Seventeen regions showed enhanced activity in shallow relative to deep encoding that was larger in magnitude for the youngest group. These regions were distributed across a broad network that included both cortical and subcortical areas. Regression analyses using the entire sample showed that age made a significant contribution to the difference in beta weights between deep and shallow encoding for 17 of the 18 identified regions in the direction predicted by the endpoint analysis. We conclude that the patterns of brain activation associated with deep and shallow encoding differ between adolescents and young adults in a manner that is consistent with the interactive specialization account of functional brain development.

Social Communication is Predicted by Inhibitory Ability and ADHD Traits in Preschool-Aged Children: A Mediation Model.

Objective: Given the role inhibitory control plays in both ADHD and communication, this study examined whether inattentive and hyperactive-impulsive traits mediate the impact of weak inhibitory ability upon the knowledge and application of pragmatic rules early in development. Method: Participants were 36 typically developing preschoolers and their caregivers. ADHD traits were assessed per caregiver report. Inhibition was assessed in children using a distraction task. Pragmatic language was assessed by asking children about hypothetical social situations (knowledge) and by asking caregivers to report on children’s actual communicative behaviors (application). Results: Individual differences in inhibition predicted both facets of pragmatic language development. Hyperactive-impulsive behaviors were a significant mediator of this relationship—but only with regard to children’s ability to effectively apply pragmatic rules in everyday life. Conclusion: Our findings suggest that social communication difficulties in some young children are a downstream consequence of hyperactive-impulsive behaviors that arise from poorly developed inhibitory control.

An illusion of 3-D motion with the Ternus display.

We attempted to eliminate the percept of element motion in the Ternus display by connecting the display elements so that they appeared to be a single object. On each trial, the display elements (two discs) appeared either separated or connected (either via a white line or side by side) and subjects reported whether they observed element motion or group motion at various ISIs. Although it was hypothesized that element motion would be eliminated in the connected condition, subjects observed element motion at short ISIs in the form of a three dimensional illusion in which one element appeared to rotate out in front of (or behind) the other. Implications for short range and long range motion processes are discussed.

Ratings of Everyday Executive Functioning (REEF): A Parent-Report Measure of Preschoolers' Executive Functioning Skills.

Executive functioning (EF) facilitates the development of academic, cognitive, and social-emotional skills and deficits in EF are implicated in a broad range of child psychopathologies. Although EF has clear implications for early development, the few questionnaires that assess EF in preschoolers tend to ask parents for global judgments of executive dysfunction and thus do not cover the full range of EF within the preschool age group. Here we present a new measure of preschoolers’ EF—the Ratings of Everyday Executive Functioning (REEF)—that capitalizes on parents’ observations of their preschoolers’ (i.e., 3- to 5-year-olds) behavior in specific, everyday contexts. Over 4 studies, items comprising the REEF were refined and the measure’s reliability and validity were evaluated. Factor analysis of the REEF yielded 1 factor, with items showing strong internal reliability. More important, children’s scores on the REEF related to both laboratory measures of EF and another parent-report EF questionnaire. Moreover, reflecting divergent validity, the REEF was more strongly related to measures of EF as opposed to measures of affective styles. The REEF also captured differences in children’s executive skills across the preschool years, and norms at 6-month intervals are reported. In summary, the REEF is a new parent-report measure that provides researchers with an efficient, valid, and reliable means of assessing preschoolers’ executive functioning.