Developmentally sensitive measures of executive function in preschool children

Individual differences in growth in executive function across the transition to school predict externalizing and internalizing behaviors and self-perceived academic success at 6 years of age

Building on an existing latent variable analysis of executive function (EF) in children (N=191, 57% boys and 43% girls) making the transition to school (Hughes et al. (2010), Developmental Neuropsychology, vol. 35, pp. 20-36), the current study both documented average developmental improvements from 4 to 6years of age and examined individual differences in EF growth in relation to latent factors for two sets of child outcome measures at 6years: (a) first-grade teachers' ratings of emotional symptoms, hyperactivity, and conduct/peer problems and (b) children's self-perceived academic and social competencies. With effects of concurrent verbal ability and EF controlled, variation in EF slopes across the transition to school predicted variation in latent constructs for (a) all four problem behavior subscales and (b) children's self-reported academic (but not social) competence. These findings underscore the clinical and educational significance of early individual differences in EF and highlight the value of adopting a developmental perspective.

Believing what you're told: young children's trust in unexpected testimony about the physical world

How do children resolve conflicts between a self-generated belief and what they are told? Four studies investigated the circumstances under which toddlers would trust testimony that conflicted with their expectations about the physical world. Thirty-month-olds believed testimony that conflicted with a naive bias (Study 1), and they also repeatedly trusted testimony that conflicted with an event they had just seen (Study 2)-even when they had an incentive to ignore the testimony (Study 3). Children responded more skeptically if they could see that the testimony was wrong as it was being delivered (Study 3), or if they had the opportunity to accumulate evidence confirming their initial belief before hearing someone contradict it (Study 4). Together, these studies demonstrate that toddlers have a robust bias to trust even surprising testimony, but this trust can be influenced by how much confidence they have in their initial belief.

Tracking executive function across the transition to school: a latent variable approach

This longitudinal study of executive function (EF) addressed three questions. These concerned: (i) the validity of EF as a latent construct underpinning performance at ages 4 and 6 on tests of planning, inhibitory control, and working memory; (ii) developmental change in EF across these time-points, which straddled children's transition to school; and (iii) verbal ability and family income as predictors of base-line individual differences and variation in the slopes of EF development. Confirmatory factor analyses of data from a socially diverse sample of 191 children supported the validity of a single EF construct at both time-points; a MIMIC (multiple indicators, multiple causes) model showed equally good fit for boys and girls. Latent growth models demonstrated that verbal mental age and family income predicted EF intercepts, but EF slopes were only related to verbal mental age. Across the transition to school, less able children (but not children from low income families) showed greater gains in EF than their peers.

Impulsive-reflective attitude, behavioural inhibition and motor skills: Are they linked?

The present study aims to examine whether the inhibitory processes and impulsive-cognitive style can influence the emergence of coordination level among 61 children aged 3 to 5 years. Luria’s tapping tasks, Day—Night tasks, Hand—Candle tasks, Go—NoGo tasks and the Trail Making Tests of Reitan, all involving inhibitory processes, were conducted. The reflective attitude of children was determined with Kagan’s Matching Familiar Figures Test. The performances of unipedal stance, overarm throw and hopping were recorded for each child. The results showed that the inhibition task performances were correlated with coordination level for the three motor skills for the 3—4-year-olds children only. More specifically, the non-verbal inhibition was more a coordination level predictor than the verbal or delayed inhibition.

The relationship between working memory capacity and executive functioning: evidence for a common executive attention construct

Attentional control has been conceptualized as executive functioning by neuropsychologists and as working memory capacity by experimental psychologists. We examined the relationship between these constructs using a factor analytic approach in an adult life span sample. Several tests of working memory capacity and executive function were administered to more than 200 subjects between 18 and 90 years of age, along with tests of processing speed and episodic memory. The correlation between working memory capacity and executive functioning constructs was very strong (r = .97), but correlations between these constructs and processing speed were considerably weaker (rs approximately .79). Controlling for working memory capacity and executive function eliminated age effects on episodic memory, and working memory capacity and executive function accounted for variance in episodic memory beyond that accounted for by processing speed. We conclude that tests of working memory capacity and executive function share a common underlying executive attention component that is strongly predictive of higher level cognition.

Contributions of modern measurement theory to measuring executive function in early childhood: An empirical demonstration

This study demonstrates the merits of evaluating a newly developed battery of executive function tasks, designed for use in early childhood, from the perspective of item response theory (IRT). The battery was included in the 48-month assessment of the Family Life Project, a prospective longitudinal study of 1292 children oversampled from low-income and African American families. IRT models were applied to a select set of tasks to demonstrate empirically (a) a principled method for item evaluation, including the utility of item characteristic curves; (b) how to explicitly test whether the measurement properties of executive function tasks are invariant across mutually exclusive subgroups of youths; (c) how the precision of measurement of a given task can vary according to underlying child ability; and (d) the utility of using IRT-based versus percentage correct scores. Results are discussed with respect to the importance of developing psychometrically sound and scalable instruments that facilitate the measurement of interindividual differences in intraindividual change of executive function across the early childhood period.

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

Flexibility is a cornerstone of adaptive behavior and is made possible by a family of processes referred to collectively as executive functions. Executive functions vary in efficacy from individual to individual and also across developmental time. Infants and young children, for example, have difficulty flexibly adapting their behavior, and often repeat actions that are no longer appropriate. And although older children do not typically make such striking errors, they have more difficulty exercising control than adolescents and adults. Such developmental variability parallels (at least in some respects) inter-individual variability in executive functions. Individuals who suffer damage or dysfunction in regions of the prefrontal cortex, for example, often experience difficulty in flexibly adapting their behavior to changes in context. As well, genetic differences between individuals are strongly associated with differences in executive control. Parallels between developmental and inter-individual variability suggest hypotheses about possible mechanisms underlying the development of executive functions but carry risks when interpreted improperly. Overcoming these pitfalls will require mechanistic characterizations of executive functioning that are more deeply rooted in developmental principles. Copyright © 2010 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website.

Exekutive Funktionen: Zugrundeliegende kognitive Prozesse und deren Korrelate bei Kindern im späten Vorschulalter

Zusammenfassung. Die Bedeutung der Exekutiven Funktionen im Vorschulalter rückt zunehmend in den Fokus entwicklungspsychologischer Forschungsliteratur. Diese exekutiven Kontrollprozesse sind nicht nur zentral für die kognitive, soziale und motorische Entwicklung der Kinder im späten Vorschulalter, sondern gelten ebenso als bedeutsame Prädiktoren für den Schulerfolg. Die vorliegende Studie versucht auf der Grundlage der Daten von insgesamt 410 Kindern (61–88 Monate) die Frage von Entwicklungsveränderungen und Beziehungsmuster verschiedener Prozesse Exekutiver Funktionen zu klären. Die Befunde sprechen für eine wichtige Entwicklungsphase der Exekutiven Funktionen im späten Vorschulalter und bedeutsame Zusammenhänge zwischen den Exekutiven Funktionen und den Individualfaktoren Sprache, Intelligenz, Motorik und Selbstregulation sowie dem Umweltfaktor sozioökonomischer Status. Kein Zusammenhang wurde allerdings zwischen den Exekutiven Funktionen und der elterlichen Unterstützung bzw. Förderung gefunden. Die Ergebnisse werden bezüglich der Struktur des Konstrukts der Exekutiven Funktionen und hinsichtlich der Relevanz der Exekutiven Funktionen im Rahmen der Entwicklungsvoraussetzungen für die Schulbereitschaft diskutiert.

Effortful Control and Adaptive Functioning of Homeless Children: Variable- and Person-focused Analyses

Homeless children show significant developmental delays across major domains of adaptation, yet research on protective processes that may contribute to resilient adaptation in this highly disadvantaged group of children is extremely rare. This study examined the role of effortful control for adaption in 58 homeless children, ages 5-6, during their transition to school. Effortful control skills were assessed using children's performance on four standard executive functioning tasks. Adaptive functioning was assessed by teacher report of academic competence, peer competence, and internalizing and externalizing symptoms. Variable-focused and person-focused results indicate that effortful control may be an important marker of school readiness and resilience. Controlling for child IQ, parenting quality, and socio-demographic risks, effortful control emerged as the most significant predictor of all four salient developmental domains of adaptation as well as of resilient status of homeless children. Implications of these findings are discussed for future research and design of interventions.

The Development of Cognitive Skills and Gains in Academic School Readiness for Children from Low-Income Families

This study examined developmental associations between growth in domain-general cognitive processes (working memory and attention control) and growth in domain-specific skills (emergent literacy and numeracy) across the pre-kindergarten year, and their relative contributions to kindergarten reading and math achievement. One hundred sixty-four Head Start children (44% African American or Latino; 57% female) were followed longitudinally. Path analyses revealed that working memory and attention control predicted growth in emergent literacy and numeracy skills during the pre-kindergarten year, and furthermore, that growth in these domain-general cognitive skills made unique contributions to the prediction of kindergarten math and reading achievement, controlling for growth in domain-specific skills. These findings extend research highlighting the importance of working memory and attention control for academic learning, demonstrating the effects in early childhood, prior to school entry. We discuss the implications of these findings for pre-kindergarten programs, particularly those designed to reduce the school readiness gaps associated with socio-economic disadvantage.

Emotion-related self-regulation and its relation to children's maladjustment

The development of children's emotion-related self-regulation appears to be related to, and likely involved in, many aspects of children's development. In this review, the distinction between effortful self-regulatory processes and those that are somewhat less voluntary is discussed, and literature on the former capacities is reviewed. Emotion-related self-regulation develops rapidly in the early years of life and improves more slowly into adulthood. Individual differences in children's self-regulation are fairly stable after the first year or two of life. Such individual differences are inversely related to at least some types of externalizing problems. Findings for internalizing problems are less consistent and robust, although emotion-related self-regulation appears to be inversely related to internalizing problems after the early years. Self-regulatory capacities have been related to both genetic and environmental factors and their interaction. Some interventions designed to foster self-regulation and, hence, reduce maladjustment, have proved to be at least partially effective.

More than a matter of getting 'unstuck': flexible thinkers use more abstract representations than perseverators

Why do people perseverate, repeating prior behaviours that are no longer appropriate? Many accounts point to isolated deficits in processes such as inhibition or attention. We instead posit a fundamental difference in rule representations: flexible switchers use active representations that rely on later-developing prefrontal cortical areas and are more abstract, whereas perseverators use latent representations that rely on earlier-developing posterior cortical and subcortical areas and are more stimulus-specific. Thus, although switchers and perseverators should apply the rules they use to familiar stimuli equally reliably, perseverators should show unique limitations in generalizing their rules to novel stimuli, a process that requires abstract representations. Two behavioural experiments confirmed this counterintuitive prediction early in development. Three-year-old children sorted cards by one rule, were asked to switch to another rule, and then were asked simply to continue their behaviour, with novel cards. Perseverators applied the rule they were using (the first rule) just as reliably as switchers applied the rule they were using (the second rule) with familiar cards; however, only switchers generalized their rule to novel cards. This finding supports an early link between active representations that support switching and abstract representations that support generalization. We interpret this synergy in terms of prefrontal cortical development.

The Factor Structure of Effortful Control and Measurement Invariance Across Ethnicity and Sex in a High-Risk Sample

Measurement invariance of a one-factor model of effortful control (EC) was tested for 853 low-income preschoolers (M age = 4.48 years). Using a teacher-report questionnaire and seven behavioral measures, configural invariance (same factor structure across groups), metric invariance (same pattern of factor loadings across groups), and partial scalar invariance (mostly the same intercepts across groups) were established across ethnicity (European Americans, African Americans and Hispanics) and across sex. These results suggest that the latent construct of EC behaved in a similar way across ethnic groups and sex, and that comparisons of mean levels of EC are valid across sex and probably valid across ethnicity, especially when larger numbers of tasks are used. The findings also support the use of diverse behavioral measures as indicators of a single latent EC construct.

Test selection, adaptation, and evaluation: a systematic approach to assess nutritional influences on child development in developing countries

BACKGROUND

Evaluating the impact of nutrition interventions on developmental outcomes in developing countries can be challenging since most assessment tests have been produced in and for developed country settings. Such tests may not be valid measures of children's abilities when used in a new context.

AIMS

We present several principles for the selection, adaptation, and evaluation of tests assessing the developmental outcomes of nutrition interventions in developing countries where standard assessment tests do not exist. We then report the application of these principles for a nutrition trial on the Indonesian island of Lombok.

SAMPLE

Three hundred children age 22-55 months in Lombok participated in a series of pilot tests for the purpose of test adaptation and evaluation. Four hundred and eighty-seven 42-month-old children in Lombok were tested on the finalized test battery.

METHODS

The developmental assessment tests were adapted to the local context and evaluated for a number of psychometric properties, including convergent and discriminant validity, which were measured based on multiple regression models with maternal education, depression, and age predicting each test score.

RESULTS

The adapted tests demonstrated satisfactory psychometric properties and the expected pattern of relationships with the three maternal variables. Maternal education significantly predicted all scores but one, maternal depression predicted socio-emotional competence, socio-emotional problems, and vocabulary, while maternal age predicted socio-emotional competence only.

CONCLUSION

Following the methodological principles we present resulted in tests that were appropriate for children in Lombok and informative for evaluating the developmental outcomes of nutritional supplementation in the research context. Following this approach in future studies will help to determine which interventions most effectively improve child development in developing countries.

Training and transfer effects of executive functions in preschool children

Executive functions, including working memory and inhibition, are of central importance to much of human behavior. Interventions intended to improve executive functions might therefore serve an important purpose. Previous studies show that working memory can be improved by training, but it is unknown if this also holds for inhibition, and whether it is possible to train executive functions in preschoolers. In the present study, preschool children received computerized training of either visuo-spatial working memory or inhibition for 5 weeks. An active control group played commercially available computer games, and a passive control group took part in only pre- and posttesting. Children trained on working memory improved significantly on trained tasks; they showed training effects on non-trained tests of spatial and verbal working memory, as well as transfer effects to attention. Children trained on inhibition showed a significant improvement over time on two out of three trained task paradigms, but no significant improvements relative to the control groups on tasks measuring working memory or attention. In neither of the two interventions were there effects on non-trained inhibitory tasks. The results suggest that working memory training can have significant effects also among preschool children. The finding that inhibition could not be improved by either one of the two training programs might be due to the particular training program used in the present study or possibly indicate that executive functions differ in how easily they can be improved by training, which in turn might relate to differences in their underlying psychological and neural processes.

The development and coherence of future-oriented behaviors during the preschool years

Although previous research has identified a number of interesting aspects of future thinking in adults, little is known about the developmental trajectory and coherence of future-oriented behaviors during early childhood. The primary goal of this study was to explore these issues by administering a battery of tasks assessing different aspects of future thinking, including mental time travel, delay of gratification, planning, and prospective memory, to 72 preschoolers. Results revealed that performance on all of the tasks increased significantly between 3 and 5 years of age. Although most tasks were correlated, suggesting "behavioral" coherence, many of these significant correlations dropped out once age and receptive vocabulary were controlled. These results are discussed with respect to theories about, and measurement of, future orientation.

A hierarchical competing systems model of the emergence and early development of executive function

The hierarchical competing systems model (HCSM) provides a framework for understanding the emergence and early development of executive function--the cognitive processes underlying the conscious control of behavior--in the context of search for hidden objects. According to this model, behavior is determined by the joint influence of a developmentally invariant habit system and a conscious representational system that becomes increasingly influential as children develop. This article describes a computational formalization of the HCSM, reviews behavioral and computational research consistent with the model, and suggests directions for future research on the development of executive function.

A hierarchical competing systems model of the emergence and early development of executive function

The hierarchical competing systems model (HCSM) provides a framework for understanding the emergence and early development of executive function--the cognitive processes underlying the conscious control of behavior--in the context of search for hidden objects. According to this model, behavior is determined by the joint influence of a developmentally invariant habit system and a conscious representational system that becomes increasingly influential as children develop. This article describes a computational formalization of the HCSM, reviews behavioral and computational research consistent with the model, and suggests directions for future research on the development of executive function.

Gene-environment interactions across development: Exploring DRD2 genotype and prenatal smoking effects on self-regulation

Genetic factors dynamically interact with both pre- and postnatal environmental influences to shape development. Considerable attention has been devoted to gene-environment interactions (G x E) on important outcomes (A. Caspi & T. E. Moffitt, 2006). It is also important to consider the possibility that these G x E effects may vary across development, particularly for constructs like self-regulation that emerge slowly, depend on brain regions that change qualitatively in different developmental periods, and thus may be manifested differently. To illustrate one approach to exploring such developmental patterns, the relation between variation in the TaqIA polymorphism, related to D2 dopamine receptor expression and availability, and prenatal exposure to tobacco was examined in two exploratory studies. First, in 4-week-old neonates, genotype-exposure interactions were observed for attention and irritable reactivity, but not for stress dysregulation. Second, in preschool children, genotype was related to Preschool Trail Making Test (K. A. Espy and M. F. Cwik, 2004) task performance on conditions requiring executive control; children with both the A1+ genotype and a history of prenatal tobacco exposure displayed disproportionately poor performance. Despite study limitations, these results illustrate the importance of examining the interplay between genetic and prenatal environmental factors across development.

A hierarchical competing systems model of the emergence and early development of executive function

The hierarchical competing systems model (HCSM) provides a framework for understanding the emergence and early development of executive function--the cognitive processes underlying the conscious control of behavior--in the context of search for hidden objects. According to this model, behavior is determined by the joint influence of a developmentally invariant habit system and a conscious representational system that becomes increasingly influential as children develop. This article describes a computational formalization of the HCSM, reviews behavioral and computational research consistent with the model, and suggests directions for future research on the development of executive function.

Young children's yes bias: How does it relate to verbal ability, inhibitory control, and theory of mind?

The aim of the present study was to investigate how young children reduce a yes bias, the tendency to answer 'yes' to yes-no questions. Specifically, we examined three possible factors: verbal ability, inhibitory control and theory of mind. Results revealed that verbal ability and inhibitory control were strongly associated with a yes bias even after controlling for age. Regression analyses revealed that these two factors significantly predicted a yes bias. Theory of mind was not significantly correlated with a yes bias. The results indicate that young children may have to inhibit a dominant 'yes' response when they are supposed to respond 'no'. The development of verbal skills may reduce young children's yes biases.

Executive functions and school readiness intervention: impact, moderation, and mediation in the Head Start REDI program

Despite their potentially central role in fostering school readiness, executive function (EF) skills have received little explicit attention in the design and evaluation of school readiness interventions for socioeconomically disadvantaged children. The present study examined a set of five EF measures in the context of a randomized-controlled trial of a research-based intervention integrated into Head Start programs (Head Start REDI). Three hundred fifty-six 4-year-old children (17% Hispanic, 25% African American; 54% girls) were followed over the course of the prekindergarten year. Initial EF predicted gains in cognitive and social-emotional skills and moderated the impact of the Head Start REDI intervention on some outcomes. The REDI intervention promoted gains on two EF measures, which partially mediated intervention effects on school readiness. We discuss the importance of further study of the neurobiological bases of school readiness, the implications for intervention design, and the value of incorporating markers of neurobiological processes into school readiness interventions.

The childhood executive functioning inventory (CHEXI): a new rating instrument for parents and teachers

Poor executive functioning has been shown to be of central importance in disruptive behavior disorders such as attention deficit hyperactivity disorder (ADHD), and a large number of laboratory measures of executive functioning have been developed. There are, however, few available questionnaires tapping executive functioning and those that exist also include items focused directly on the symptom criteria for ADHD, which makes it difficult to draw conclusions regarding executive functioning per se. In the present study, a new rating instrument, the Childhood Executive Functioning Inventory (CHEXI) was therefore introduced. This instrument was shown to have good test-retest reliability. Using factor analysis, two factors tapping working memory and inhibition emerged using parent ratings and these two factors were replicated using teacher ratings. Modest, yet mostly significant, relations to laboratory measures of working memory and inhibition were found. Ratings on the CHEXI were also found to be significantly related to ADHD symptoms as well as early academic achievement. Interestingly, ratings on the CHEXI and laboratory measures of working memory and inhibition were shown to explain independent variance in ADHD symptoms and academic achievement, which point to the importance of using a multi-assessment strategy when studying executive functioning.

It's Fascinating Research

Verbal irony is nonliteral language that makes salient a discrepancy between expectations and reality. For researchers who study verbal irony, a critical question is: How do we grasp the meaning of ironic language? The parallel-constraint-satisfaction approach holds promise as an answer to this question. By this account, multiple cues to ironic intent, such as tone of voice, incongruity, and knowledge of the speaker, are processed rapidly and in parallel and this information is coordinated with the utterance itself in order to construct a coherent interpretation that is the best fit for the activated information. Recently, research with individuals who struggle with irony comprehension (typically developing children, individuals with autism-spectrum disorder, individuals with brain injury) has provided new clues about the complex process by which ironic meaning is inferred.

Cognitive flexibility in preschoolers: the role of representation activation and maintenance

Preschoolers' lack of cognitive flexibility has often been attributed to perseverative processing. This study investigates alternative potential sources of difficulty such as deficits in activating previously ignored information and in maintaining currently relevant information. In Experiment 1, a new task tapping attentional switching was designed to isolate the difficulty of overriding an initial representation, that is, perseverative processing ('Perseveration' version), and the difficulty of activating a previously ignored representation, that is, activation deficit ('Activation-deficit' version). Three-year-olds' performance suggested that inflexibility may primarily stem from an activation deficit. Control experiments confirmed that the difficulty of the 'Activation-deficit' version could not be attributed to the effect of attraction to novelty. In Experiment 2, 'distraction' errors, alleged to reflect a failure to maintain a relevant representation, and 'perseverative' errors were distinguished. The results highlighted the important role of representation maintenance in flexibility. The present study indicates that preschoolers' lack of cognitive flexibility is multi-determined and prompts us to reconsider the role of perseveration.

Bilingual experience and executive functioning in young children

Advanced inhibitory control skills have been found in bilingual speakers as compared to monolingual controls (Bialystok, 1999). We examined whether this effect is generalized to an unstudied language group (Spanish-English bilingual) and multiple measures of executive function by administering a battery of tasks to 50 kindergarten children drawn from three language groups: native bilinguals, monolinguals (English), and English speakers enrolled in second-language immersion kindergarten. Despite having significantly lower verbal scores and parent education/income level, Spanish-English bilingual children's raw scores did not differ from their peers. After statistically controlling for these factors and age, native bilingual children performed significantly better on the executive function battery than both other groups. Importantly, the relative advantage was significant for tasks that appear to call for managing conflicting attentional demands (Conflict tasks); there was no advantage on impulse-control (Delay tasks). These results advance our understanding of both the generalizability and specificity of the compensatory effects of bilingual experience for children's cognitive development.

Risk for sleep-disordered breathing and executive function in preschoolers

BACKGROUND

Pediatric sleep-disordered breathing is known to negatively impact cognitive development. While a theoretical basis has been proposed for the developmental effect of pediatric sleep-disordered breathing on executive function specifically, this had not been directly examined among preschool-age children. This population may be particularly vulnerable if school-readiness is compromised. The purpose of the current study was to use a multi-dimensional approach to assessing executive function among preschool-age children at risk for sleep-disordered breathing.

METHODS

Thirty-nine preschool children were administered executive function tasks assessing the dimensions of inhibition, working memory, and planning as part of a larger study. A parent or guardian completed a validated questionnaire concerning the child's snoring and other behaviors indicating risk for sleep-disordered breathing.

RESULTS

After controlling for age in a series of regressions, higher parent-reported risk for sleep-disordered breathing was associated with substantially lower performance on each executive function dimension. In comparing the group means of children at high and low risk for sleep-disordered breathing, the single snoring frequency item also showed that children who snored frequently or almost always had lower performance on each executive function dimension.

CONCLUSIONS

The results suggest that sleep-disordered breathing may be associated with impaired executive function in preschoolers, with its strongest impact on the inhibition dimension, further emphasizing the importance of early intervention for sleep-disordered breathing in this early age group.

Executive functions in preschool children with aggressive behavior: impairments in inhibitory control

The question whether executive function (EF) deficits in children are associated with conduct problems remains controversial. Although the origins of aggressive behavior are to be found in early childhood, findings from EF studies in preschool children with aggressive behavior are inconsistent. The current study aimed to investigate whether preschool children with aggressive behavior show impairments in EF. From a population-based sample, 82 preschool children who were showing aggressive behavior as indicated by scores at or above the 93rd percentile on the Aggressive Behavior Scale of the CBCL 1 1/2-5 were selected. These children with aggressive behavior were matched on IQ to a group of typically developing control children (N = 99). Six neuropsychological tasks were administered to assess set shifting, inhibition, working memory and verbal fluency. A factor analysis was conducted which yielded one clear factor: inhibition. Aggressive preschool children showed poorer performance on this inhibition factor than control children and boys performed worse on this factor than girls. This association between aggressive behavior and inhibition deficits was maintained after controlling for attention problems. In addition, gender differences in all EFs measured were found with boys exhibiting more impairment in EF than girls. These findings demonstrate that preschool children with aggressive behavior show impairments in inhibition, irrespective of attention problems.

Cognitive and emotional control and perspective taking and their relations to empathy in 5-year-old children

The experience of empathy has been described as involving both emotional and cognitive components. The primary hypothesis tested in this study is that cognition and emotion are integrated within 2 distinct types of abilities-control and perspective taking-and that interactions between emotional and cognitive control and between affective and cognitive perspective taking would be related to children's empathic responding. We also hypothesized that boys' control and perspective-taking skills would be more strongly related to empathy than would those of girls. Fifty-seven 5-year-olds completed tasks measuring cognitive control, cognitive and affective perspective taking, and empathy, and their mothers completed a measure of children's emotional control. Results indicated that cognitive perspective taking moderated the relation between affective perspective taking and empathy. In addition, the relation between cognitive inhibitory control and empathy was moderated by gender; boys' control was positively related to empathy, but girls' control was marginally negatively related to empathy.

Sorting between dimensions: conditions of cognitive flexibility in preschoolers

The Dimensional Change Card Sorting task frequently is used to measure extradimensional shifting abilities in preschool children. In two studies, we investigated what makes this extradimensional shifting task difficult. In Study 1 with 61 2- to 4-year-olds, we showed that extradimensional shifts from one dimension to another are more difficult than reversal shifts within a dimension (even with irrelevant variation on a second dimension). Study 2 with 77 3- and 4-year-olds further confirmed this finding using a computerized paradigm and showed that sorting instructions are critical for 3-year-olds' difficulties with extradimensional shifts. This finding is taken to suggest that 3-year-olds have particular problems with spontaneously classifying one object in two different ways.

Executive functioning in preschool children born very preterm: relationship with early white matter pathology

Despite evidence for executive dysfunction in school-aged preterm children, less is known about the early development of these difficulties or their underlying neuropathology. This study used prospective longitudinal data from a regional cohort of 88 very preterm and 98 full-term comparison children to examine the executive functioning (EF) of preschool children born very preterm. The relationship between the severity of neonatal cerebral white matter (WM) abnormalities on magnetic resonance imaging (MRI) at term equivalent and children's EF at ages two and four years (corrected age) was examined. At age four, very preterm children with WM abnormalities performed less well than full-term children on the Detour Reaching Box, a measure of behavioral inhibition and cognitive flexibility, even after controlling for child IQ, SES, and medical background. Examination of patterns of EF performance between the ages of 2 and 4 years showed that the performance of all groups improved with age. However, very preterm children with mild and moderate-severe WM abnormalities were characterized by higher rates of consistent performance impairments. These findings support the presence of early and persistent executive difficulties in preschool children born very preterm, and highlight the importance of white matter pathology in the development of executive impairments.

Effects of aerobic exercise on overweight children's cognitive functioning: a randomized controlled trial

The study tested the effect of aerobic exercise training on executive function in overweight children. Ninety-four sedentary, overweight but otherwise healthy children (mean age = 9.2 years, body mass index 85th percentile) were randomized to a low-dose (20 min/day exercise), high-dose (40 min/day exercise), or control condition. Exercise sessions met 5 days/week for 15 weeks. The Cognitive Assessment System (CAS), a standardized test of cognitive processes, was administered individually before and following intervention. Analysis of covariance on posttest scores revealed effects on executive function. Group differences emerged for the CAS Planning scale (p = .03). Planning scores for the high-dose group were significantly greater than those of the control group. Exercise may prove to be a simple, yet important, method of enhancing aspects of children's mental functioning that are central to cognitive and social development.

Biological systems and the development of self-regulation: integrating behavior, genetics, and psychophysiology

Self-regulation is the ability to control inner states or responses with respect to thoughts, emotions, attention, and performance. As such, it is a critical aspect of development and fundamental to personality and behavioral adjustment. In this review, we focus on attentional, cognitive, and emotional control as we discuss the genetic mechanisms and brain mechanisms that contribute to individual differences in self-regulation. We conclude with a discussion of the implications for deviations in the development of this complex construct and suggestions for future research.