Verbal ability and executive functioning development in preschoolers at head start

Research suggests that executive functioning skills may enhance the school readiness of children from disadvantaged homes. Questions remain, however, concerning both the structure and the stability of executive functioning among preschoolers. In addition, there is a lack of research addressing potential predictors of longitudinal change in executive functioning during early childhood. This study examined the structure of executive functioning from fall to spring of the preschool year using a multimethod battery of measures. Confirmatory factor analyses revealed a unidimensional model fit the data well at both time points, and tests of measurement invariance across time points indicated that children's mean latent executive functioning scores significantly improved over time. Verbal ability was a significant predictor of longitudinal change in executive functioning. Theoretical implications and directions for future research are discussed.     

Limitations in Verbal Fluency Following Heavy Burdens of Early Childhood Diarrhea in Brazilian Shantytown Children

The effects of heavy burdens of diarrhea in the first 2 years of life on specific executive control function like verbal fluency are not well understood. In previous studies, we have shown associations of early childhood diarrhea (ECD) with nonverbal intelligence and school functioning. Therefore, we postulated that ECD might affect early neuropsychological development leading to long-term deficits in normal cognitive development. Based on our extensive 14-year prospective cohort studies of early childhood diarrheal illnesses in a Brazilian shantytown community, we examined ECD correlations between specific impairments of higher mental function and executive skills in shantytown children 5–10 years later (now at 6–12) years of age. Specifically we examined whether heavy diarrheal illnesses correlate with reduced performance on selected tests of executive function. Our study, for the first time, suggests a disproportional impairment in semantic but not phonetic fluency in a subset of children with heavy burdens of diarrhea in their first 2 years of life even when controlling for maternal education, breastfeeding, and child schooling. Similar semantic decrements have been associated with impaired recovery from brain injury. These exploratory studies suggest the importance of verbal fluency tests to assess executive functioning in children challenged by poor nutrition and diarrhea in early life. In addition, our unique findings show the potential influences of early childhood diarrhea on language development that is so critical to productive adulthood and potentially set a foundation for new neuropsychological approaches, which assess early burdens of enteric illnesses on childhood development.     

Limitations in verbal fluency following heavy burdens of early childhood diarrhea in Brazilian shantytown children.

The effects of heavy burdens of diarrhea in the first 2 years of life on specific executive control function like verbal fluency are not well understood. In previous studies, we have shown associations of early childhood diarrhea (ECD) with nonverbal intelligence and school functioning. Therefore, we postulated that ECD might affect early neuropsychological development leading to long-term deficits in normal cognitive development. Based on our extensive 14-year prospective cohort studies of early childhood diarrheal illnesses in a Brazilian shantytown community, we examined ECD correlations between specific impairments of higher mental function and executive skills in shantytown children 5-10 years later (now at 6-12) years of age. Specifically we examined whether heavy diarrheal illnesses correlate with reduced performance on selected tests of executive function. Our study, for the first time, suggests a disproportional impairment in semantic but not phonetic fluency in a subset of children with heavy burdens of diarrhea in their first 2 years of life even when controlling for maternal education, breastfeeding, and child schooling. Similar semantic decrements have been associated with impaired recovery from brain injury. These exploratory studies suggest the importance of verbal fluency tests to assess executive functioning in children challenged by poor nutrition and diarrhea in early life. In addition, our unique findings show the potential influences of early childhood diarrhea on language development that is so critical to productive adulthood and potentially set a foundation for new neuropsychological approaches, which assess early burdens of enteric illnesses on childhood development.     

Attention development in infants and preschool children born preterm: a review

A potential mechanism that can explain preterm children's heightened risk for the development of later cognitive and behavioral problems is attention. Attention is the ability of an infant or child to orient to, to shift between and to maintain focus on events, objects, tasks, and problems in the external world, processes which are all dependent on the functioning of attentional networks in the brain. The aim of this paper is to provide a review of the literature on attention development in children born preterm during the first 4 years of life. First, research examining the differences between preterm and full-term children indicates that early attention development in infants born preterm is less optimal and that these differences increase when infants grow into toddlers. Second, studies investigating individual differences within preterm populations reveal the influence of both biological factors and environmental factors. Third, individual differences in early orienting and sustained attention have been shown to be predictive of later attentional, cognitive and behavioral functioning in children born preterm. The importance of long-term follow-up studies, with a focus on individual developmental trajectories in orienting, sustained and executive attention, is emphasized.     

Prenatal cigarette exposure and infant learning stimulation as predictors of cognitive control in childhood

Prenatal exposures to neurotoxins and postnatal parenting practices have been shown to independently predict variations in the cognitive development and emotional-behavioral well-being of infants and children. We examined the independent contributions of prenatal cigarette exposure and infant learning stimulation, as well as their inter-relationships in predicting variations in the proficiency of executive attention, a core element of cognitive control and self-regulation. Participants were an ethnic-racially, socio-economically diverse sample of 249 children followed from birth in the Project on Human Development in Chicago Neighborhoods. We obtained histories of prenatal exposure to alcohol, cigarettes, and other drugs, and we assessed socio-economic status and learning stimulation during a home visit when the participants were infants. In childhood we utilized the Attention Networks Test to assess the proficiency of executive attention during two home visits, one year apart. Accounting for age, SES, prenatal alcohol exposure, and baseline performance, we found that prenatal cigarette exposure impaired the speed of executive attention. Infant learning stimulation mitigated these effects, and predicted better accuracy of executive attention as well, suggestive of both protective and health promoting effects. Effect sizes for these relations, whether examined independently or by their inter-relationships, were comparable to if not greater in magnitude than the effects of age on speed and accuracy, highlighting the importance of these very early experiences in shaping the proficiency of self-regulation. Since executive attention is central to cognitive control and self-regulation, previously described relations between prenatal cigarette exposure, parenting practices, and some forms of childhood psychopathology may be contingent on how early learning stimulation contributes to the proficiency of executive attention through direct and indirect effects. Furthermore, considering the prolonged developmental trajectory of executive attention, interventions to support provision of learning stimulation may mitigate poor outcomes for some at-risk children by promoting development of more proficient executive attention.     

The effects of bilingualism on toddlers' executive functioning

Bilingual children have been shown to outperform monolingual children on tasks measuring executive functioning skills. This advantage is usually attributed to bilinguals’ extensive practice in exercising selective attention and cognitive flexibility during language use because both languages are active when one of them is being used. We examined whether this advantage is observed in 24-month-olds who have had much less experience in language production. A battery of executive functioning tasks and the cognitive scale of the Bayley test were administered to 63 monolingual and bilingual children. Native bilingual children performed significantly better than monolingual children on the Stroop task, with no difference between groups on the other tasks, confirming the specificity of bilingual effects to conflict tasks reported in older children. These results demonstrate that bilingual advantages in executive control emerge at an age not previously shown.     

Measuring executive function skills in young children in Kenya

Interest in measuring executive function skills in young children in low- and middle-income country contexts has been stymied by the lack of assessments that are both easy to deploy and scalable. This study reports on an initial effort to develop a tablet-based battery of executive function tasks, which were designed and extensively studied in the United States, for use in Kenya. Participants were 193 children, aged 3–6 years old, who attended early childhood development and education centers. The rates of individual task completion were high (65–100%), and 85% of children completed three or more tasks. Assessors indicated that 90% of all task administrations were of acceptable quality. An executive function composite score was approximately normally distributed, despite higher-than-expected floor and ceiling effects on inhibitory control tasks. Children’s simple reaction time (β = –0.20, p = .004), attention-related behaviors during testing (β = 0.24, p = .0005), and age (β = –0.24, p = .0009) were all uniquely related to performance on the executive function composite. Results are discussed as they inform efforts to develop valid and reliable measures of executive function skills among young children in developing country contexts.     

The relation between measures of cognitive and motor functioning in 5- to 6-year-old children

Specific relations between executive functions (working memory capacity, planning and problem-solving, inhibitory control) and motor skill performance (anticipatory motor planning, manual dexterity) were examined in 5- to 6-year-old children (N = 40). Results showed that the two motor skill components were not correlated. Additionally, it was found that response planning performance was a significant predictor of anticipatory motor planning performance, whereas inhibitory control and working memory capacity measures were significant predictors of manual dexterity scores. Taken together, these results suggest that cognitive and motor skills are linked, but that manual dexterity and anticipatory motor planning involve different specialized skills. The current study provides support for specific relations between cognitive and motor performance, which has implications for early childhood cognitive-motor training and intervention programs.     

The roles of different executive functioning skills in young children’s mental computation and applied mathematical problem-solving

This study investigated the relationships of four executive functioning skills (including verbal working memory, spatial working memory, inhibitory control, and cognitive flexibility) with young children’s mental computation and applied mathematical problem-solving. Two hundred and twenty-five Chinese kindergarteners were tested with a battery of general cognitive, executive functioning and mathematics skills. Results showed that when children’s age, gender, non-verbal intelligence, and listening comprehension skills were controlled, verbal working memory and cognitive flexibility were significant correlates of mental computation, whereas verbal working memory, spatial working memory, and cognitive flexibility were significant correlates of applied mathematical problem-solving. Inhibitory control was not significantly associated with the two domains of mathematics under investigation. The findings highlight the differential roles of different executive functioning skills in early mathematical skills and offer practical implication for helping young children in learning complex mathematical skills.     

Executive function outcomes of children with traumatic brain injury sustained before three years

Traumatic brain injury (TBI) is a common cause of disability in childhood. While the outcomes of TBI sustained in school years has been heavily researched, very little is known about the impact of TBI in infants and young children. The aim of this study was to investigate the impact of TBI on executive function (EF) in children who sustained a TBI before 3 years of age. A group of 55 children, 19 with a mild TBI, 16 children with a moderate-severe TBI, and 20 uninjured comparison children participated. The EF of children aged 3 to 6 years were compared using child-based measures of attentional control and information processing. Parents completed questionnaires rating their child's EF. Severity groups differed on the child-based EF measure of attentional control with children with TBI performing below the control group. There were no significant group differences for information processing or parent-rated EF. It appears that children who sustain a TBI before the age of 3 years display impairments in some areas of attentional control 3–4 years postinjury. The findings fit with the existing EF literature for older children.     

Examining the Regulatory and Reactive Temperamental Characteristics as Predictors of Low Income Preschool Children’s Executive Function

The current study is an examination of low income children’s reactive and regulatory temperamental characteristics as predictors of their executive function, with a particular focus on children’s regulatory temperament (i.e., inhibitory control and attentional focusing) as moderators of associations between reactive temperament (i.e., negative emotionality) and executive function. Participants were 291 children (159 boys) ages 37 to 70 months (M = 53.88 months, SD = 6.44 months) enrolled in 17 classrooms within 3 different preschools serving low income children in two Midwestern cities in the United States. Temperament was assessed via parent report during Fall 2014, and executive function were assessed via structured tasks implemented by independent researchers during Spring and Summer 2015. SAS PROC MIXED was used to test hierarchical regression models of children nested within classrooms. After controlling for child age, gender, ethnicity, and parent education, regulatory temperament moderated the association between reactive temperament and executive function. Children’s reactive temperament was inversely associated with their executive function. These findings suggest that understanding children’s regulatory and reactive temperamental characteristics may help to improve their executive functioning in early childhood.     

Performance-based and parent ratings of attention in children treated for a brain tumor: The significance of radiation therapy and tumor location on outcome

Children are at increased risk for cognitive difficulties following the diagnosis and treatment of a brain tumor. Radiation therapy (RT) and tumor location are commonly-cited predictors of neurocognitive functioning. Disruptions to foundational neurocognitive processes such as attention, working memory, and processing speed underlie declines on measures of general intellectual functioning. While several studies have examined visual sustained attention in pediatric brain tumor patients, auditory sustained attention has yet to be examined. This study employs a longitudinal design to examine performance-based and parent ratings of attention in children undergoing surgical resection of a brain tumor (n = 29) and treated with (n = 11) or without (n = 18) RT at 6.79 months post-surgery (baseline) and then again at 30.56 months post-surgery (follow-up). The measures include an auditory continuous performance test (CPT) and parent ratings of attention and hyperactivity on a behavior rating scale. Ultimately, children treated with and without RT performed similarly on performance-based and parent ratings of attention. However, the performance on the auditory CPT differed according to tumor location, with children with infratentorial tumors committing more inattention and inhibitory control errors compared to children with supratentorial tumors. Parent ratings did not differ according to tumor location, and parent ratings and auditory sustained attention performance are not significantly correlated. The findings are interpreted in the context of neurocognitive and brain development.     

Neuropsychological Functioning in Children with Posttraumatic Stress Disorder

Posttraumatic stress disorder (PTSD) has been associated with deficits in the areas of verbal memory and learning, executive functioning, working memory, and attention in adults. Findings have been less consistent in the few studies examining neuropsychological functioning in childhood PTSD, which are often limited by comparing children with PTSD to children without trauma histories, making it unclear whether observed neuropsychological deficits are related to trauma exposure or to PTSD symptomatology. In an ethnically diverse sample of 62 children who witnessed intimate partner violence (n = 27 PTSD+ and 35 PTSD?), children with PTSD exhibited slower and less effective learning, heightened sensitivity to interference, and impaired effect of rehearsal on memory acquisition on the California Verbal Learning Test – Children's Version, a word list learning task. Both groups performed in the below average range on measures of executive functioning, attention, and intellectual ability.     

Identification and Description of New Tests of Executive Functioning in Children

The understanding of executive functioning in pediatric neuropsychological evaluation is of clinical significance, yet there are few developmentally appropriate executive function measures that have been adequately normed in this population. The present study provides normative data, collected on a sample of 89 normal children from ages 7-12, for several measures thought to be appropriate for assessing executive functioning in children. Executive function measures were selected and/or modified to be developmentally appropriate, to tap less complex and integrative aspects of executive function, and to assess fundamental working memory (Self-Ordered Pointing: Delayed Alternation/Non-alternation) and inhibitory control (Developmental Stroop tasks: Go/No Go) dimensions of executive functioning. The results supported the potential utility of these measures in assessing those abilities in children.     

From terrible twos to sassy sixes: The development of vocabulary and executive functioning across early childhood

Across the early childhood period of development, young children exhibit considerable growth in their executive functioning (EF) and vocabulary abilities. Understanding the developmental trajectory of these seemingly interrelated processes is important as both early vocabulary and EF have been shown to predict critical academic and socio-emotional outcomes later in childhood. Although previous research suggests that EF and vocabulary are correlated in early childhood, much of the existing longitudinal research has focused on unidirectional relations among preschool child samples. The current large-scale study, therefore, sought to examine whether children's vocabulary and EF abilities are bidirectionally related over time across four measurement waves in early childhood (i.e., at ages 2, 3, 4, and 6). At each timepoint, children's vocabulary skills were positively correlated with their concurrent EF abilities. After controlling for child sex and maternal education status, the best-fitting, cross-lagged panel model was a unidirectional model whereby children's early vocabulary scores predicted their later EF performance at each timepoint. Although age 2 EF significantly predicted age 3 vocabulary size, this association was no longer significant after accounting for maternal education status. Our results illustrate that vocabulary size plays an important role in predicting children's later EF performance across various timepoints in early childhood, even after controlling for children's initial EF scores. These findings have important implications for intervention research as fostering early vocabulary acquisition may serve as a possible avenue for improving EF outcomes in young children.

Research Highlights

• Children's vocabulary size is positively correlated with their concurrent executive functioning skill at ages 2, 3, 4, and 6
• Young children's early vocabulary scores predict their later EF performance across measurement waves, even after controlling for initial EF skill
• There is stability in children's relative vocabulary size and executive functioning performance over time in early childhood

     

The relation between cognitive and motor performance and their relevance for children’s transition to school: A latent variable approach

Both theoretically and empirically there is a continuous interest in understanding the specific relation between cognitive and motor development in childhood. In the present longitudinal study including three measurement points, this relation was targeted. At the beginning of the study, the participating children were 5–6-year-olds. By assessing participants’ fine motor skills, their executive functioning, and their non-verbal intelligence, their cross-sectional and cross-lagged interrelations were examined. Additionally, performance in these three areas was used to predict early school achievement (in terms of mathematics, reading, and spelling) at the end of participants’ first grade. Correlational analyses and structural equation modeling revealed that fine motor skills, non-verbal intelligence and executive functioning were significantly interrelated. Both fine motor skills and intelligence had significant links to later school achievement. However, when executive functioning was additionally included into the prediction of early academic achievement, fine motor skills and non-verbal intelligence were no longer significantly associated with later school performance suggesting that executive functioning plays an important role for the motor-cognitive performance link.     

Executive function in children with high and low attentional skills: Correspondences between behavioural and cognitive profiles

Cognitive performance was compared between two groups of typically developing children, who had been observed and rated as differing significantly in their attentional skills at school. The participants were 24 8‐ and 9‐year‐old children scoring poorly relative to peers, on a classroom observation scale and teacher rating scale for attention, hyperactivity, and impulsivity [low‐attentional skills (LAS) group] and 24 sex‐ and age‐matched children scoring at a high level compared to peers [high‐attentional skills (HAS) group]. The two groups were compared on a series of cognitive tasks to assess executive function (EF). The LAS group performed within the typical range yet at a significantly lower level than the HAS group on the majority of the EF tasks administered, namely working memory and inhibition measures, even though there were no significant differences between the groups on a measure of intellectual ability. Working memory measures followed by measures of inhibition emerged as the best predictors of group membership. These findings provide empirical evidence that there are individual differences in attentional skills. Specifically, that there is a relationship between behavioural inattention, hyperactivity, and impulsivity and cognitive performance on working memory and inhibitory control tasks.     

Young Deceivers: Executive Functioning and Antisocial Lie‐telling in Preschool Aged Children

The present study examined the emergence of antisocial lie‐telling in very young children. Lie‐telling was studied in relation to executive functioning skills and children's abilities to identify both truths and lies. A total of 65 children (M_{age in months} = 31.75, SD = 1.87) participated in a modified temptation resistance paradigm (TRP; designed to elicit spontaneous lies). Executive functioning was measured through an inhibitory control task and a forward search planning task. The Truth/Lie Identification task was administered (Lyon, Carrick, & Quas, 2010 ) to measure children's abilities to accurately distinguish truths and lies. During the TRP, a total of 89.23% children peeked at the toy when a research assistant left the room, and of those children, 29.31% lied to the research assistant. Significant differences on executive functioning measures were found between lie‐tellers and confessors, as well as for the Truth/Lie Identification task. Lie‐tellers had higher scores on measures of inhibitory control and forward search planning. Lie‐tellers also had higher accuracy on the Truth/Lie Identification task than confessors. This study provides a unique contribution to the literature by examining 2.5‐year‐old children's emerging lie‐telling abilities, a relatively understudied age during which fledgling lie‐telling emerges. Copyright © 2016 John Wiley & Sons, Ltd.     

Are sluggish cognitive tempo symptoms associated with executive functioning in preschoolers?

The aim of this study is to investigate whether sluggish cognitive tempo (SCT) symptoms are associated with neurocognitive task performance and ratings of real-world executive functioning (EF) in preschoolers at risk for attention-deficit/hyperactivity disorder (ADHD). The associations between parent- and teacher-rated SCT symptoms and neuropsychological task performance and ratings of EF in 61 4-year-old preschool children (51 boys, 10 girls) with self-regulation difficulties were examined, with regression analyses controlling for the effects of ADHD inattention symptoms. In the study sample, higher teacher-rated SCT symptoms are significantly associated with poorer performance on tasks of visual-perceptual abilities, auditory and visual attention, sustained and selective attention, inhibitory control, pre-numerical/numerical concepts, and slower processing speed, but SCT symptoms are not significantly associated with working memory, attention shifting or cognitive flexibility when controlling for ADHD inattention. Higher parent-rated SCT symptoms are significantly associated with visual-perceptual abilities. ADHD inattention symptoms are more strongly associated than SCT with daily life EF ratings; neither parent- nor teacher-rated SCT symptoms are significantly associated with daily life ratings of inhibition, working memory, or planning/organization after controlling for ADHD inattention. This study suggests that SCT symptoms contribute to EF deficits at least on neurocognitive tasks assessing visual-perceptual/spatial abilities, attention to detail and processing speed, as observed in this sample of young children at risk for ADHD, and may be an important intervention target.     

Developmental Changes in Visual and Auditory Inhibition in Early Childhood

The development of executive functions in the preschool years is not fully understood. Although there exists a large body of research investigating the maturation of executive functioning in school‐aged children, little is known about the emergence of such skills, in particular inhibition, among preschool‐aged children. Understanding developmental changes of inhibition proficiencies and deficiencies early in childhood is important for charting typical and atypical developmental trajectories. Using an adapted computerized paradigm, the present study examined age‐related changes in visual and auditory inhibition in 68 typically developing children aged 3 to 6 years. The results indicated that although similar age‐related gains in performance occurred across both visual and auditory inhibition tasks, certain modality‐specific differences emerged in terms of accuracy and reaction time. These results suggest that the newly adapted measures used are sensitive enough to capture developmental variations in inhibition. Copyright © 2012 John Wiley & Sons, Ltd.