Understanding genetic, neurophysiological, and experiential influences on the development of executive functioning: the need for developmental models

To what extent is dot comparison an appropriate measure of approximate number system?

Introduction

Number sense has been systematically measured using dot comparison tasks. However, recent studies have reported that performance on dot comparison might be influenced inhibitory control and visual properties of dot arrays. In the present study, we analysed the influence of continuous magnitude, inhibitory control, and numerical ratio on the dot comparison performance of preschool children.

Methods

Participants were 517 preschool children from 13 different schools in Chile. Children completed a dot comparison and two inhibitory control tasks. Gebuis and Reynvoet method was used to create well-controlled dot arrays for use in the dot comparison task. A logistic mixed effects model was conducted to predict participants' dot comparison accuracy. Continuous magnitude and ratio were entered as level-1 predictors and inhibitory control as level-2 predictors.

Results

The results showed that all predictors made a significant contribution to dot comparison accuracy. Furthermore, a significant double interaction (inhibitory control x continuous magnitude) and a triple interaction (inhibitory control x continuous magnitude x ratio) showed that the contribution of inhibitory control skills in dot comparison accuracy depends on the continuous properties of dot arrays and ratio.

Discussion

These findings suggest that preschool children rely more on continuous magnitudes than numerosity in dot comparison tasks. They also indicate that the greater children's inhibitory control, the more able they are to respond based on numerosity in fully incongruent trials, particularly when ratio is low (easiest items). Taken together, the above findings support the competing processes account provided that both ANS and inhibitory control skills influence performance on dot comparison tasks.

Longitudinal investigation of executive function development employing task-based, teacher reports, and fNIRS multimethodology in 4- to 5-year-old children

Increased focus on resting-state functional connectivity (rsFC) and the use and accessibility of functional near-infrared spectroscopy (fNIRS) have advanced knowledge on the interconnected nature of neural substrates underlying executive function (EF) development in adults and clinical populations. Less is known about the relationship between rsFC and developmental changes in EF during preschool years in typically developing children, a gap the present study addresses employing task-based assessment, teacher reports, and fNIRS multimethodology. This preregistered study contributes to our understanding of the neural basis of EF development longitudinally with 41 children ages 4-5. Changes in prefrontal cortex (PFC) rsFC utilizing fNIRS, EF measured with a common task-based assessment (Day-Night task), and teacher reports of behavior (BRIEF-P) were monitored over multiple timepoints: Initial Assessment, 72 h follow-up, 1 Month Follow-up, and 4 Month Follow-up. Measures of rsFC were strongly correlated 72 h apart, providing evidence of high rsFC measurement reliability using fNIRS with preschool-aged children. PFC rsFC was positively correlated with performance on task-based and report-based EF assessments. Children's PFC functional connectivity at rest uniquely predicted later EF, controlling for verbal IQ, age, and sex. Functional connectivity at rest using fNIRS may potentially show the rapid changes in EF development in young children, not only neurophysiologically, but also as a correlate of task-based EF performance and ecologically-relevant teacher reports of EF in a classroom context.

On Neuroeducation: Why and How to Improve Neuroscientific Literacy in Educational Professionals

New findings from the neurosciences receive much interest for use in the applied field of education. For the past 15 years, neuroeducation and the application of neuroscience knowledge were seen to have promise, but there is presently some lack of progress. The present paper states that this is due to several factors. Neuromyths are still prevalent, and there is a confusion of tongues between the many neurodisciplines and the domains of behavioral and educational sciences. Second, a focus upon cognitive neuroimaging research has yielded findings that are scientifically relevant, but cannot be used for direct application in the classroom. A third factor pertains to the emphasis which has been on didactics and teaching, whereas the promise of neuroeducation for the teacher may lie more on pedagogical inspiration and support. This article states that the most important knowledge and insights have to do with the notion of brain plasticity; the vision that development is driven by an interaction between a person's biology and the social system. This helps individuals to select and process information, and to adapt to the personal environment. The paper describes how brain maturation and neuropsychological development extend through the important period of adolescence and emergent adulthood. Over this long period, there is a major development of the Executive Functions (EFs) that are essential for both cognitive learning, social behavior and emotional processing and, eventually, personal growth. The paper describes the basic neuroscience knowledge and insights - or "neuroscientific literacy" - that the educational professional should have to understand and appreciate the above-described themes. The authors formulate a proposal for four themes of neuroscience content "that every teacher should know." These four themes are based on the Neuroscience Core Concepts formulated by the Society for Neuroscience. The authors emphasize that integrating neuroscientific knowledge and insights in the field of education should not be a one-way street; attempts directed at improving neuroscientific literacy are a transdisciplinary undertaking. Teacher trainers, experts from the neuroscience fields but also behavioral scientists from applied fields (notable applied neuropsychologists) should all contribute to for the educational innovations needed.

Executive Control and Adolescent Health: Toward A Conceptual Framework

Executive control is a set of cognitive abilities that may impact a variety of adolescent health behaviors and outcomes; however, research on executive control as a contributor to the physical health of youth is relatively limited. Therefore, the current article explores the possible role of executive control in adolescent health by reviewing relevant literature and proposing a conceptual framework to guide future research in this area. The development of executive control from preschool through adolescence is described, with particular attention to executive control in the unique health context of adolescence. A new conceptual model is proposed, focusing on how executive control may play a critical role in supporting health in adolescence and beyond through the mechanisms of attentional, behavioral, and emotional control. Literature exploring associations between youth executive control and key health behaviors (including diet, physical activity, sleep and substance use) is reviewed. Researchers and clinicians are encouraged to consider executive control as an important cross-cutting contributor to health during adolescence and beyond and to incorporate this construct into longitudinal studies of health.

Developmental differences in approaches to nonsymbolic comparison tasks

Nonsymbolic comparison tasks are widely used to measure children's and adults' approximate number system (ANS) acuity. Recent evidence has demonstrated that task performance can be influenced by changes to the visual characteristics of the stimuli, leading some researchers to suggest it is unlikely that an ANS exists that can extract number information independently of the visual characteristics of the arrays. Here, we analysed 124 children's and 120 adults' dot comparison accuracy scores from three separate studies to investigate individual and developmental differences in how numerical and visual information contribute to nonsymbolic numerosity judgements. We found that, in contrast to adults, the majority of children did not use numerical information over and above visual cue information to compare quantities. This finding was consistent across different studies. The results have implications for research on the relationship between dot comparison performance and formal mathematics achievement. Specifically, if most children's performance on dot comparison tasks can be accounted for without the involvement of numerical information, it seems unlikely that observed correlations with mathematics achievement stem from ANS acuity alone.

Changes in frontal and posterior cortical activity underlie the early emergence of executive function

Executive function (EF) is a key cognitive process that emerges in early childhood and facilitates children's ability to control their own behavior. Individual differences in EF skills early in life are predictive of quality-of-life outcomes 30 years later (Moffitt et al., 2011). What changes in the brain give rise to this critical cognitive ability? Traditionally, frontal cortex growth is thought to underlie changes in cognitive control (Bunge & Zelazo, 2006; Moriguchi & Hiraki, 2009). However, more recent data highlight the importance of long-range cortical interactions between frontal and posterior brain regions. Here, we test the hypothesis that developmental changes in EF skills reflect changes in how posterior and frontal brain regions work together. Results show that children who fail a "hard" version of an EF task and who are thought to have an immature frontal cortex, show robust frontal activity in an "easy" version of the task. We show how this effect can arise via posterior brain regions that provide on-the-job training for the frontal cortex, effectively teaching the frontal cortex adaptive patterns of brain activity on "easy" EF tasks. In this case, frontal cortex activation can be seen as both the cause and the consequence of rule switching. Results also show that older children have differential posterior cortical activation on "easy" and "hard" tasks that reflects continued refinement of brain networks even in skilled children. These data set the stage for new training programs to foster the development of EF skills in at-risk children.

The emergent executive: a dynamic field theory of the development of executive function

Executive function (EF) is a central aspect of cognition that undergoes significant changes in early childhood. Changes in EF in early childhood are robustly predictive of academic achievement and general quality of life measures later in adulthood. We present a dynamic neural field (DNF) model that provides a process-based account of behavior and developmental change in a key task used to probe the early development of executive function—the Dimensional Change Card Sort (DCCS) task. In the DCCS, children must flexibly switch from sorting cards either by shape or color to sorting by the other dimension. Typically, 3-year-olds, but not 5-year-olds, lack the flexibility to do so and perseverate on the first set of rules when instructed to switch. Using the DNF model, we demonstrate how rule-use and behavioral flexibility come about through a form of dimensional attention. Further, developmental change is captured by increasing the robustness and precision of dimensional attention. Note that although this enables the model to effectively switch tasks, the dimensional attention system does not “know” the details of task-specific performance. Rather, correct performance emerges as a property of system–wide interactions. We show how this captures children’s behavior in quantitative detail across 14 versions of the DCCS task. Moreover, we successfully test a set of novel predictions with 3-year-old children from a version of the task not explained by other theories.

Positive affect facilitates task switching in the dimensional change card sort task: implications for the shifting aspect of executive function

Using the modified Dimensional Change Card Sort task, we examined the influence of positive affect on task switching by inspecting various markers for the costs, including restart cost, switch cost and mixing cost. Given that the executive-control processes that underlie switching performance--i.e., inhibition or shifting--are distinct from the component processes that underlie non-switching performance--i.e., stimulus evaluation, resource allocation or response execution--we hypothesised that if positive affect facilitates task switching via executive-control processes, rather than via component processes, positive affect would reduce both switch and restart costs, but not mixing cost, because both switch and restart costs rely on executive processes, while mixing cost imposes only minimal demands on executive processes. We found beneficial effects of positive affect on both restart and switch costs, but not on mixing costs. These results suggest that positive affect improves switching abilities via executive processes rather than via component processes.

Behavioral Sleep Problems and their Potential Impact on Developing Executive Function in Children

Bedtime resistance and night waking are common sleep problems throughout childhood, especially in the early years. These sleep problems may lead to difficulties in neurobehavioral functioning, but most research into childhood sleep problems has not emphasized the importance of the developmental context in which disruptions in neurobehavioral and daytime functioning occur. We review the development of sleep as well as executive functioning (EF) in childhood and suggest that EF may be particularly vulnerable to the effects of these common childhood sleep problems because of its prolonged course of maturation. Behavioral problems associated with common sleep problems suggest poor self-regulation in the context of sleep loss, and developing EF skills play important roles in self-regulation. A research agenda that considers a developmental approach to sleep and sleep problems in the context of childhood EF performance is outlined to promote future research in this area.

CITATION

Turnbull K; Reid GJ; Morton JB. Behavioral sleep problems and their potential impact on developing executive function in children. SLEEP 2013;36(7):1077-1084.

Perseveration and the status of 3-year-olds' knowledge in a card-sorting task: evidence from studies involving congruent flankers

Infants and young children often perseverate despite apparent knowledge of the correct response. Two Experiments addressed questions concerning the status of such knowledge in the context of a card-sorting task. In Experiment 1, three groups of 3-year-olds sorted bivalent cards one way and then were instructed to switch and sort the same cards using new rules under varying conditions of support offered by congruent flankers. Although formal aspects of the task such as higher-order rule use, stimulus redescription, and dimensional shifting remained constant across all conditions, use of the new rules increased with parametric increases in environmental support for the use of the new rules. In Experiment 2, 3-year-olds were more likely to switch and use new rules when test stimuli were flanked by congruent flankers rather than neutral flankers, even though both conditions made equivalent demands on attentional inhibition. Thus, in both experiments, children's knowledge of the new rules proved to be adequate under less demanding conditions but inadequate under more demanding conditions. These findings are consistent with the idea that children's knowledge is graded in strength rather than present or absent.