The Contribution of Executive Functions to Emergent Mathematic Skills in Preschool Children

Mathematical ability is related to both activation of the prefrontal cortex in neuroimaging studies of adults and to executive functions in school-age children. The purpose of this study was to determine whether executive functions were related to emergent mathematical proficiency in preschool children. Preschool children (N = 96) were administered an executive function battery that was reduced empirically to working memory (WM), inhibitory control (IC), and shifting abilities by calculating composite scores derived from principal component analysis. Both WM and IC predicted early arithmetic competency, with the observed relations robust after controlling statistically for child age, maternal education, and child vocabulary. Only IC accounted for unique variance in mathematical skills, after the contribution of other executive functions were controlled statistically as well. Specific executive functions are related to emergent mathematical proficiency in this age range. Longitudinal studies using structural equation modeling are necessary to better characterize these ontogenetic relations.     

Executive Function and Theory of Mind in 2 Year Olds: A Family Affair?

This study aimed to enhance our understanding of neuropsychological functioning in children with early-treated phenylketonuria (PKU) and assess the relative impact of white matter abnormalities (WMA) and neurotransmitter deficiencies on cognitive functions in this population. The study consisted of 33 children with early-treated PKU and 34 healthy control children aged between 7 to 18 years. All children had a neuropsychological evaluation that included measures of general intelligence, attention, processing speed, memory and learning, executive function, and academic achievement. Children in the PKU group also had a magnetic resonance (MR) brain scan. When compared with the control group, the PKU group exhibited global cognitive impairment including lower IQ, attention problems, slow information processing, reduced learning capacity, mild executive impairments, and educational difficulties. Children in the PKU group with extensive WMA (n = 14) displayed significant impairments across all cognitive domains. Metabolic control correlated weakly to moderately with attention, executive, and memory/learning factors. Within the PKU group, regressions revealed that executive function and attention factors were independently related to severity of WM pathology and age, while the memory and learning factor was independently related to metabolic control and age. It is concluded that children with early-treated PKU exhibit a global pattern of impairment, with a particular deficit in processing speed. WM pathology extending into frontal and subcortical regions correlates with the greatest deficits and a profile of impairment consistent with diffuse WM damage. Our findings also offer some support for dopamine depletion in the prefrontal cortex, however adverse consequences as a result of norepinephrine and serotonin deficiencies should not be discounted.     

Are neuropsychological impairments in children with early-treated phenylketonuria (PKU) related to white matter abnormalities or elevated phenylalanine levels?

This study aimed to enhance our understanding of neuropsychological functioning in children with early-treated phenylketonuria (PKU) and assess the relative impact of white matter abnormalities (WMA) and neurotransmitter deficiencies on cognitive functions in this population. The study consisted of 33 children with early-treated PKU and 34 healthy control children aged between 7 to 18 years. All children had a neuropsychological evaluation that included measures of general intelligence, attention, processing speed, memory and learning, executive function, and academic achievement. Children in the PKU group also had a magnetic resonance (MR) brain scan. When compared with the control group, the PKU group exhibited global cognitive impairment including lower IQ, attention problems, slow information processing, reduced learning capacity, mild executive impairments, and educational difficulties. Children in the PKU group with extensive WMA (n = 14) displayed significant impairments across all cognitive domains. Metabolic control correlated weakly to moderately with attention, executive, and memory/learning factors. Within the PKU group, regressions revealed that executive function and attention factors were independently related to severity of WM pathology and age, while the memory and learning factor was independently related to metabolic control and age. It is concluded that children with early-treated PKU exhibit a global pattern of impairment, with a particular deficit in processing speed. WM pathology extending into frontal and subcortical regions correlates with the greatest deficits and a profile of impairment consistent with diffuse WM damage. Our findings also offer some support for dopamine depletion in the prefrontal cortex, however adverse consequences as a result of norepinephrine and serotonin deficiencies should not be discounted.     

Executive Functions Following Traumatic Brain Injury in Young Children: A Preliminary Analysis

To examine executive processes in young children with traumatic brain injury (TBI), we evaluated performance of 44 children who sustained moderate-to-severe TBI prior to age 6 and to 39 comparison children on delayed response (DR), stationary boxes, and spatial reversal (SR) tasks. The tasks have different requirements for holding mental representations in working memory (WM) over a delay, inhibiting prepotent responses, and shifting response set. Age at the time of testing was divided into 10- to 35- and 36- to 85-month ranges. In relation to the community comparison group, children with moderate-to-severe TBI scored significantly lower on indexes of WM/inhibitory control (IC) on DR and stationary boxes tasks. On the latter task, the Age × Group interaction indicated that performance efficiency was significantly reduced in the older children with TBI relative to the older comparison group; performance was similar in younger children irrespective of injury status. The TBI and comparison groups did not differ on the SR task, suggesting that shifting response set was not significantly altered by TBI. In both the TBI and comparison groups, performance improved with age on the DR and stationary boxes tasks. Age at testing was not significantly related to scores on the SR task. The rate of acquisition of working memory (WM) and IC increases steeply during preschool years, but the abilities involved in shifting response set show less increase across age groups (Espy, Kaufmann, & Glisky, 2001; Luciana & Nelson, 1998). The findings of our study are consistent with the rapid development hypothesis, which predicts that skills in a rapid stage of development will be vulnerable to disruption by brain injury.     

Executive functions following traumatic brain injury in young children: a preliminary analysis

To examine executive processes in young children with traumatic brain injury (TBI), we evaluated performance of 44 children who sustained moderate-to-severe TBI prior to age 6 and to 39 comparison children on delayed response (DR), stationary boxes, and spatial reversal (SR) tasks. The tasks have different requirements for holding mental representations in working memory (WM) over a delay, inhibiting prepotent responses, and shifting response set. Age at the time of testing was divided into 10- to 35- and 36- to 85-month ranges. In relation to the community comparison group, children with moderate-to-severe TBI scored significantly lower on indexes of WM/inhibitory control (IC) on DR and stationary boxes tasks. On the latter task, the Age × Group interaction indicated that performance efficiency was significantly reduced in the older children with TBI relative to the older comparison group; performance was similar in younger children irrespective of injury status. The TBI and comparison groups did not differ on the SR task, suggesting that shifting response set was not significantly altered by TBI. In both the TBI and comparison groups, performance improved with age on the DR and stationary boxes tasks. Age at testing was not significantly related to scores on the SR task. The rate of acquisition of working memory (WM) and IC increases steeply during preschool years, but the abilities involved in shifting response set show less increase across age groups (Espy, Kaufmann, & Glisky, 2001; Luciana & Nelson, 1998). The findings of our study are consistent with the rapid development hypothesis, which predicts that skills in a rapid stage of development will be vulnerable to disruption by brain injury.     

Brief report: adjustment to juvenile rheumatoid arthritis: a family systems perspective

OBJECTIVE: To examine the relations of the family environment to adjustment to juvenile rheumatoid arthritis (JRA), and to examine how those relations are influenced by child sex and age. METHOD: Ninety-four children with JRA completed a questionnaire on family environment and adjustment. RESULTS: Family cohesion was related to good adjustment, whereas family conflict was related to poor adjustment. Some relations of family cohesion to adjustment were stronger for younger than for older children. The relations of child autonomy to adjustment depended on child sex and age. CONCLUSION: The relations of the family environment to adjustment to JRA are dependent on child sex and age.     

Children’s Executive Function Attenuate the Link Between Maternal Intrusiveness and Internalizing Behaviors at School Entry

The goal of this study was to examine the independent and interactive roles of harsh-intrusive maternal behaviors and children’s executive function in the development of internalizing behaviors across the first years of school. A diverse sample (58% African American, 42% European American) of 137 children (48% female) was followed from kindergarten (age 5 years) through school entry (ages 6–7 years). At age 5, maternal harsh-intrusive parenting behaviors were rated from a mother–child structured play task, and children completed 3 executive function tasks that measured inhibitory control, working memory, and attention set-shifting. Teachers reported on children’s internalizing behaviors at ages 5, 6, and 7. Harsh-intrusive parenting behaviors at age 5 years were positively related to internalizing behaviors in the first years of school, whereas high executive function abilities at age 5 years were related to lower internalizing behaviors in the first years of school. In addition, executive function buffered the association between parenting behaviors and internalizing behaviors such that the link between harsh-intrusive parenting and child internalizing behaviors was evident only among children with low executive function and not among children with high executive function. Interventions that focus on reducing negative parenting behaviors and improving children’s executive function may prevent internalizing behaviors from increasing during times of social and academic challenge.     

Examining relationships between executive functioning and delay aversion in attention deficit hyperactivity disorder

Although motivation and cognition are often examined separately, recent theory suggests that a delay-averse motivational style may negatively impact development of executive functions (EFs), such as working memory (WM) and response inhibition (RI) for children with Attention Deficit Hyperactivity Disorder (ADHD; Sonuga-Barke, 2002 ). This model predicts that performance on delay aversion and EF tasks should be correlated for school-age children with ADHD. However, tests of these relationships remain sparse. Forty-five children ages 8 to 12 with ADHD and 46 non-ADHD controls completed tasks measuring EFs and delay aversion. Children with ADHD had poorer WM and RI than non-ADHD controls, as well as nonsignificantly worse delay aversion. Consistent with previous research, RI was not related to delay aversion. However, delay aversion did predict WM scores for children with and without ADHD. Implications for the dual-pathway hypothesis and future research on cognitive and motivational processing in ADHD are discussed.     

Executive Functioning as a Predictor of Children's Mathematics Ability: Inhibition, Switching, and Working Memory

Children's mathematical skills were considered in relation to executive functions. Using multiple measures-including the Wisconsin Card Sorting Task (WCST), dual-task performance, Stroop task, and counting span-it was found that mathematical ability was significantly correlated with all measures of executive functioning, with the exception of dual-task performance. Furthermore, regression analyses revealed that each executive function measure predicted unique variance in mathematics ability. These results are discussed in terms of a central executive with diverse functions (Shallice & Burgess, 1996) and with recent evidence from Miyake, et al. (2000) showing the unity and diversity among executive functions. It is proposed that the particular difficulties for children of lower mathematical ability are lack of inhibition and poor working memory, which result in problems with switching and evaluation of new strategies for dealing with a particular task. The practical and theoretical implications of these results are discussed, along with suggestions for task changes and longitudinal studies that would clarify theoretical and developmental issues related to executive functioning.     

Genetic Structure of Spatial and Verbal Working Memory

Working memory (WM) encompasses both short-term memory (storage) and executive functions that play an essential role in all forms of cognition. In this study, the genetic structure of storage and executive functions engaged in both a spatial and verbal WM span task is investigated using a twin sample. The sample consists of 143 monozygotic (MZ) and 93 dizygotic (DZ) Japanese twin pairs, ages 16 to 29 years. In 155 (87 MZ, 62 DZ) of these pairs, cognitive ability scores from the Kyodai Japanese IQ test are also obtained. The phenotypic relationship between WM and cognitive ability is confirmed (r = 0.26–0.44). Individual differences in WM storage and executive functions are found to be significantly influenced by genes, with heritability estimates all moderately high (43%–49%), and estimates for cognitive ability comparable to previous studies (65%). A large part of the genetic variance in storage and executive functions in both spatial and verbal modalities is due to a common genetic factor that accounts for 11% to 43% of the variance. In the reduced sample, this common genetic factor accounts for 64% and 26% of the variance in spatial and verbal cognitive ability, respectively. Additional genetic variance in WM (7%–30%) is due to modality specific factors (spatial and verbal) and a storage specific factor that may be particularly important for the verbal modality. None of the variance in cognitive ability is accounted for by the modality and storage genetic factors, suggesting these may be specific to WM.     

The relation between working memory components and ADHD symptoms from a developmental perspective

The objective was to examine the relations between attention deficit hyperactivity disorder (ADHD) symptoms and four working memory (WM) components (short-term memory and central executive in verbal and visuospatial domains) in 284 6-16-year-old children from the general population. The results showed that verbal and visuospatial short-term memory and verbal central executive uniquely contributed to inattention symptoms. Age interacted with verbal short-term memory in predicting inattention, with the relation being stronger in older children. These findings support the notion of ADHD as a developmental disorder, with changes in associated neuropsychological deficits across time. The results further indicate ADHD-related deficits in several specific WM components.     

Wisconsin Card Sorting Test performance in above average and superior school children: relationship to intelligence and age.

This study explores the relationship of intelligence and age to scores on the Wisconsin Card Sorting Test, a measure of executive function. A sample of 26 normal children with Wechsler Intelligence Scale for Children-III (WISC-III) Full-Scale IQS above 130 and 24 normal children with WISC-III Full-Scale IQS between 110 and 129 were administered the test. A comparison to published norms revealed that above average children outperformed the average 9- to 14-year-old child on every measure at every age. Multiple regression analyses statistically related the Wisconsin Card Sorting Test, perseverative, nonperseverative, total errors, and trials to the first category of intelligence. Intelligence proved to be a significant qualifier of age trends. Gender relationships were nonsignificant in a preliminary analysis.     

When flanker meets the n‐back: What EEG and pupil dilation data reveal about the interplay between the two central‐executive working memory functions inhibition and updating

We investigated the interplay between inhibition and updating, two executive working memory (WM) functions. We applied a novel task paradigm consisting of flanker stimuli presented within an n‐back task and studied the interaction between inhibitory demands and load on WM updating using behavioral measures, EEG, and pupil dilation. In contrast to studies that examine the interaction between inhibitory demands and load on WM storage components, the current task paradigm allowed testing the interaction between the executive WM components updating and inhibition. We found a reduced flanker interference effect for the highest (2‐back) updating load condition compared to lower updating load conditions on most measures. We interpret these findings as indicating that inhibitory control and WM updating are closely intertwined executive functions. Increased load on updating seemed to result in an overall more activated attentional network thus enhancing inhibitory control, such that task performance is less susceptible to distracting information.     

Executive functions and cognitive subprocesses in patients with obstructive sleep apnoea

In recent years, special interest has been focused on impairments of executive functions in patients with obstructive sleep apnoea syndrome (OSAS). However, the majority of studies have not clearly separated deficits in executive functions from impairments in other cognitive processes involved in task solving. In the present study, working memory (WM) functions of 20 patients with OSAS were compared with those of 10 age-, sex- and education-matched healthy subjects. Cognitive functions were measured four times a day; each of these measurements was accompanied by an assessment of subjective and objective daytime sleepiness. To separate dysfunctions of WM from those of additionally involved processes, n -back tasks were applied embedded in a reaction-time-decomposition approach. Deficits in n -back tasks could be observed in OSAS patients in accuracy and reaction times. However, the slowing could already be observed in simple reaction time tasks. The drop in 1-back accuracy in the morning was related to daytime sleepiness. During the afternoon, accuracy of OSAS patients dropped in 2-back tasks, an effect which correlated neither with sleepiness nor with the extent of sleep apnoea or oxygen desaturation. In conclusion, our data reflect a complex perspective upon cognitive deficits in OSAS. Cross-group differences in processing time on the higher level WM task appeared to be attributable to slowing at a more elementary cognitive processing level. In contrast, reduced accuracy during the WM task in the OSAS group could not be explained by deficits in more elementary cognitive processes.     

Cognitive development among children with early‐treated phenylketonuria

Previous research supports the notion that children with early‐treated classical phenylketonuria (PKU) have specific cognitive deficits in executive function skills. These deficits may relate to depressed levels of dopamine, due to defective tyrosine synthesis. We investigated whether deficits reported for preschoolers with early‐treated PKU are manifested also among school‐age children with PKU, and whether cognitive performance among the latter group is related to phenylalanine level at time of testing. Seventeen children with PKU and 17 age‐, sex‐, and IQ‐matched controls were tested individually on measures of executive functions. The results demonstrate that executive function deficits reported for preschoolers with PKU were not manifested in the school‐age PKU children included in this study. The authors discuss the implications of these findings for theories of the development of executive function skills.     

Behavioral inhibition and behavioral activation in young children: relations with self-regulation and adaptation to preschool in children attending Head Start

We examine a parent-report version of the measure of behavioral inhibition and behavioral activation of Carver and White (1994), the BIS/BAS scales. Participants included 42 children (mean age = 4 years, 9 months) attending Head Start programs. Information was collected on aspects of physiological and cognitive regulation, temperamental emotionality, BIS/BAS sensitivity, and teacher report of social competence and on-task behavior in the classroom. Physiological regulation was assessed by cardiac vagal tone and was measured during a baseline period and during the administration of a mildly effortful cognitive task. Cognitive regulation was assessed by executive function and was measured using two tasks that require children to inhibit a prepotent response while remembering and executing the rule for correct responding. Parents reported on behavioral inhibition and behavioral activation and aspects of child negative emotionality associated with fear and anger. Results indicated that the BIS scale was positively related to teacher reported social competence but negatively related to on-task behavior. Associations between the BIS and each of the outcome variables were independent of relations of physiological and cognitive regulation to outcomes and were present when relations between fearful emotionality and the outcomes were not. No relations were observed between any of the BAS scales and the outcome measures. Results recommend the application of neurobiological and psychophysiological approaches to the study of children's adaptation to preschool.     

Short-term memory, working memory, and executive functioning in preschoolers: longitudinal predictors of mathematical achievement at age 7 years

This study examined whether measures of short-term memory, working memory, and executive functioning in preschool children predict later proficiency in academic achievement at 7 years of age (third year of primary school). Children were tested in preschool (M age = 4 years, 6 months) on a battery of cognitive measures, and mathematics and reading outcomes (from standardized, norm-referenced school-based assessments) were taken on entry to primary school, and at the end of the first and third year of primary school. Growth curve analyses examined predictors of math and reading achievement across the duration of the study and revealed that better digit span and executive function skills provided children with an immediate head start in math and reading that they maintained throughout the first three years of primary school. Visual-spatial short-term memory span was found to be a predictor specifically of math ability. Correlational and regression analyses revealed that visual short-term and working memory were found to specifically predict math achievement at each time point, while executive function skills predicted learning in general rather than learning in one specific domain. The implications of the findings are discussed in relation to further understanding the role of cognitive skills in different mathematical tasks, and in relation to the impact of limited cognitive skills in the classroom environment.     

Relationship of negative mood with prefrontal cortex activity during working memory tasks: an optical topography study

Mood has a substantial impact on cognitive functions. Although studies have shown that the interaction between mood and cognition is mediated by the prefrontal cortex (PFC), little is known about how naturalistic mood in everyday life is associated with PFC activity during cognitive tasks. We investigated whether inter-individual variation in perceived mood under current life situations (recent week) is related to PFC activity during working memory (WM) tasks in healthy adults. Levels of positive and negative moods were quantified with the Profile of Mood States (POMS) questionnaire. PFC activities during verbal and spatial WM tasks were measured by optical topography (OT), a non-invasive low-constraint neuroimaging tool, to minimize experimental intervention in participants' moods. Group-average analysis showed significant activations in the bilateral dorsolateral PFC in both WM tasks. Correlation analysis revealed that the participants reporting higher levels of negative moods showed lower levels of PFC activity during the verbal WM task but not during the spatial WM task. This relationship was significant even after controlling for possible confounding factors such as age, gender, and task performance. Our results suggest that verbal WM is linked with naturalistic negative mood and that the PFC is involved in the mood-cognition interaction in daily circumstances.     

The role of maternal attachment in children's attachment and cognitive executive functioning: A preliminary study

The influence of maternal attachment on children's attachment and executive functioning skills through maternal sensitivity and decentered tutoring were studied in 40 middle-class mother–child dyads. Infant attachment security in the Strange Situation Procedure was related to maternal attachment security, evaluated with the Adult Attachment Interview. When the children were six–seven months of age, maternal sensitivity was evaluated. When the child was six years old, maternal decentered tutoring and the children's executive functioning were evaluated. Regression analyses indicated that maternal tutoring accounted for the association between maternal attachment and child cognitive functioning, whereas maternal sensitivity accounted for the association between maternal and child attachment.     

Physiological and neurocognitive correlates of adaptive behavior in preschool among children in Head Start

This study examined physiological and neurocognitive correlates of teacherreported adaptive behavior in preschool among children in Head Start. Child physiology was assessed by cardiac vagal tone and was measured during a baseline period and during the administration of a mildly effortful cognitive task. Neurocognitive function was measured using two tasks of executive function, which require children to inhibit a prepotent response, while remembering and executing the rule for correct responding. Parents reported on aspects of child negative emotionality associated with fear and anger. Information on child receptive language ability was also collected. Although correlates of teacher-reported social competence and on-task behavior were expected to be similar, some evidence for differentiation was obtained. Results indicated that higher resting vagal tone, vagal increase during the administration of the cognitive task, and higher levels of fearful emotionality were related to higher ratings of social competence, after adjusting for levels of on-task behavior. In contrast, lower resting vagal tone, vagal suppression in response to the cognitive task, and higher levels of executive function were associated with higher teacher ratings of on-task behavior, adjusted for social competence. Implications are considered of findings for developmental relations between social and academic competence and adaptation to preschool among children in Head Start.