Sources of variability in working memory in early childhood: A consideration of age, temperament, language, and brain electrical activity

Assessing anxiety problems in a community sample during toddlerhood: The impact of child temperament and maternal intrusiveness

Previous research indicates that child temperament and maternal behaviors are related to internalizing behaviors in children. We assessed whether maternal intrusiveness (MI) observed at 10-months would moderate the impact of temperamental fear and the impact of inhibitory control (IC) at 24 months on anxiety problems at 36 months. A mother-child interaction task was coded for MI. Behavioral tasks were given to assess children's IC. Parents completed questionnaires about their children's temperamental fear and anxiety problems. Results showed that greater temperamental fear reported at 24 months predicted greater anxiety problems reported at 36 months, regardless of MI levels. Lower levels of IC at 24 months predicted more anxiety problems reported at 36 months when children experienced greater MI. These findings illustrate the importance of examining both intrinsic and extrinsic factors, independently and interactively, that contribute to children's anxiety problems in toddlerhood.

Incorporating Evidence-Based Gamification and Machine Learning to Assess Preschool Executive Function: A Feasibility Study

Computerized assessments and digital games have become more prevalent in childhood, necessitating a systematic investigation of the effects of gamified executive function assessments on performance and engagement. This study examined the feasibility of incorporating gamification and a machine learning algorithm that adapts task difficulty to individual children's performance into a traditional executive function task (i.e., Flanker Task) with children ages 3-5. The results demonstrated that performance on a gamified version of the Flanker Task was associated with performance on the traditional version of the task and standardized academic achievement outcomes. Furthermore, gamification grounded in learning science and developmental psychology theories applied to a traditional executive function measure increased children's task enjoyment while preserving psychometric properties of the Flanker Task. Overall, this feasibility study indicates that gamification and adaptive machine learning algorithms can be successfully incorporated into executive function assessments with young children to increase enjoyment and reduce data loss with developmentally appropriate and intentional practices.

Immature event-related alpha dynamics in children compared with the young adults during inhibition shown by day-night stroop task

Introduction

Inhibitory control develops gradually from infancy to childhood and improves further during adolescence as the brain matures. Related previous studies showed the indispensable role of task-related alpha power during inhibition both in children and young adults. Nonetheless, none of the studies have been able to investigate the direct differences in brain responses between children and young adults when confronted with a stimulus that should be inhibited. Because, unlike event-related designs, task-related designs involve continuous tasks over a certain period, which precludes the possibility of making such a comparison. Accordingly, by employing event-related design, the present study first time in the literature, aimed to analyze the event-related alpha phase locking and event-related alpha synchronization/ desynchronization to differentiate the inhibitory processes in children compared to young adults.

Methods

Twenty children between the ages of 6 to 7  years and 20 healthy young adult subjects between the ages of 18 to 30  years were included in the study. Day-night Stroop task was applied to all subjects during 18-channel EEG recordings. Event-related time-frequency analysis was performed with the complex Morlet Wavelet Transform for the alpha frequency band (8-13  Hz). Event related spectral perturbation (ERSP) in three different time windows (0-200  ms, 200-400  ms, 400-600  ms) and Event-related phase locking in the early time window (0-400  ms) was calculated.

Results

The children had increased alpha power in early and late time windows but decreased alpha phase locking in the early time windows compared to young adults. There were also topological differences between groups; while young adults had increased alpha phase-locking in frontal and parietal electrode sites, children had increased occipital alpha power and phase locking.

Discussion

The shift in event-related alpha power observed from posterior to anterior regions with age may suggest a progressive maturation of the frontal areas involved in inhibitory processes from childhood to adulthood. The results of the present study showed that children and young adults had different EEG oscillatory dynamics during inhibitory processes at alpha frequency range.

The Interplay between Socioeconomic Status, Parenting and Temperament Predicts Inhibitory Control at Two Years of Age

This paper investigates the interplay between environmental factors (socioeconomic status (SES) and parenting) and temperament in the development of inhibitory control (IC) at 2 years of age. We administered to toddlers (n = 59) a delay of gratification task which measures IC in the context of self-regulation. Parents reported their toddlers' temperament, parenting strategies, and SES. We hypothesized that poorer IC would be associated with more reactive temperament, less effortful control, lower SES and inconsistent/coercive parenting practices. Finally, we explored the interaction between temperament, parenting and SES. We found that both coercive parenting and low-SES were negatively correlated to IC at the age of 2 years. Temperamental reactivity was unrelated to IC, whereas temperamental effortful control (EC) was positively associated with IC. Results revealed a moderation effect of EC on the influence of coercive parenting and SES in toddlers' IC. Toddlers from lower SES backgrounds and with lower EC were more affected by inconsistent/coercive parenting practices and showed the poorest IC. In contrast, toddlers exhibiting high and average levels of EC seemed to be protected from the detrimental effect of low-SES and inconsistent/coercive parenting on IC. These results suggest that strengthening toddlers' EC and improving parents' parenting skills might be especially relevant for the development of IC in the context of self-regulation, particularly by preventing self-regulatory problems in children from socioeconomically deprived environments. Future studies with larger samples, focusing on populations from severe socioeconomically deprived environments, or intervention studies will be needed in order to confirm and expand our findings.

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

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

Self-regulation and frontal EEG alpha activity during infancy and early childhood: A multilevel meta-analysis

Integrating behavioral and neurophysiological measures has created new and advanced ways to understand the development of self-regulation. Electroencephalography (EEG) has been used to examine how self-regulatory processes are related to frontal alpha power during infancy and early childhood. However, findings across previous studies have been inconsistent. To address this issue, the current meta-analysis synthesized all prior literature examining associations between individual differences in self-regulation and frontal EEG alpha power (baseline and/or task). In total, 23 studies consisting of 1275 participants between 1 month and 6 years of age were included, which yielded 149 effect sizes. Findings of the three-level meta-analytic model demonstrated a non-significant overall association between self-regulation and frontal alpha power. Yet, significant moderating effects were found for self-regulation construct (emotion regulation, effortful control, executive function), self-regulation measurement (behavioral task, computer assessment, lab observation, questionnaire), and children's mean age. Self-regulation was only significantly correlated with frontal alpha power when studies focused on the executive functioning construct. Moreover, the use of behavioral tasks or questionnaires and a higher mean age of the children resulted in small but significant effect size estimates. Higher frontal alpha power values were related to higher order top-down mechanisms of self-regulation, indicating that these mechanisms might become stronger when the frontal cortex is sufficiently developed. The findings of the current meta-analysis highlight the importance of longitudinal analyses and multimethod approaches in future work to reach a more comprehensive understanding of the role of frontal EEG alpha activity in the etiology of individual differences in early self-regulation. RESEARCH HIGHLIGHTS: The first meta-analysis of individual differences in self-regulation and frontal EEG alpha power during infancy and early childhood demonstrated a non-significant overall association. Moderation analyses revealed that variations in frontal alpha power were significantly associated with executive function, but not with effortful control and emotion regulation. Frontal alpha power was related to variations in self-regulation when measured by behavioral tasks and questionnaires, but not via computer assessments and lab observations. The association between individual differences in self-regulation and frontal alpha power becomes significantly stronger with age.

The Acceptability, Feasibility, and Utility of Portable Electroencephalography to Study Resting-State Neurophysiology in Rural Communities

Electroencephalography (EEG) provides a non-invasive means to advancing our understanding of the development and function of the brain. However, the majority of the world’s population residing in low and middle income countries has historically been limited from contributing to, and thereby benefiting from, such neurophysiological research, due to lack of scalable validated methods of EEG data collection. In this study, we establish a standard operating protocol to collect approximately 3 min each of eyes-open and eyes-closed resting-state EEG data using a low-cost portable EEG device in rural households through formative work in the community. We then evaluate the acceptability of these EEG assessments to young children and feasibility of administering them through non-specialist workers. Finally, we describe properties of the EEG recordings obtained using this novel approach to EEG data collection. The formative phase was conducted with 9 families which informed protocols for consenting, child engagement strategies and data collection. The protocol was then implemented on 1265 families. 977 children (Mean age = 38.8 months, SD = 0.9) and 1199 adults (Mean age = 27.0 years, SD = 4) provided resting-state data for this study. 259 children refused to wear the EEG cap or removed it, and 58 children refused the eyes-closed recording session. Hardware or software issues were experienced during 30 and 25 recordings in eyes-open and eyes-closed conditions respectively. Disturbances during the recording sessions were rare and included participants moving their heads, touching the EEG headset with their hands, opening their eyes within the eyes-closed recording session, and presence of loud sounds in the testing environment. Similar to findings in laboratory-based studies from high-income settings, the percentage of recordings which showed an alpha peak was higher in eyes-closed than eyes-open condition, with the peak occurring most frequently in electrodes at O1 and O2 positions, and the mean frequency of the alpha peak was found to be lower in children (8.43 Hz, SD = 1.73) as compared to adults (10.71 Hz, SD = 3.96). We observed a deterioration in the EEG signal with prolonged device usage. This study demonstrates the acceptability, feasibility and utility of conducting EEG research at scale in a rural low-resource community, while highlighting its potential limitations, and offers the impetus needed to further refine the methods and devices and validate such scalable methods to overcome existing research inequity.

Private Speech and the Development of Self-Regulation: The Importance of Temperamental Anger

In this study (N=160), we observed children's private (i.e., self-directed) speech (PS) during a challenging puzzle task at age 3 and assessed whether the amount and maturity of their PS predicted their inhibitory control (IC) at age 4 and indirectly emotion regulation at age 9. Additionally, we examined whether the direct and indirect effects of PS were moderated by children's temperament. As expected, the maturity of children's PS was positively associated with IC and this association was stronger when children were reported as higher in anger reactivity by mothers (the interaction accounting for 11% of the explained variance). Children low in temperamental anger tend to have good IC and may not need to use PS. When children were at or above the mean on anger reactivity, PS maturity was indirectly associated with better emotion regulation at age 9 through an influence on IC at age 4 (index of moderated mediation =1.03 [.10, 3.60]). Findings suggest that PS is an important self-regulatory tool for 3-year-olds who typically experience and express anger.

EEG signatures of cognitive and social development of preschool children-a systematic review

Background

Early identification of preschool children who are at risk of faltering in their development is essential to ensuring that all children attain their full potential. Electroencephalography (EEG) has been used to measure neural correlates of cognitive and social development in children for decades. Effective portable and low-cost EEG devices increase the potential of its use to assess neurodevelopment in children at scale and particularly in low-resource settings. We conducted a systematic review aimed to synthesise EEG measures of cognitive and social development in 2-5-year old children. Our secondary aim was to identify how these measures differ across a) the course of development within this age range, b) gender and c) socioeconomic status (SES).

Methods and findings

A systematic literature search identified 51 studies for inclusion in this review. Data relevant to the primary and secondary aims was extracted from these studies and an assessment for risk of bias was done, which highlighted the need for harmonisation of EEG data collection and analysis methods across research groups and more detailed reporting of participant characteristics. Studies reported on the domains of executive function (n = 22 papers), selective auditory attention (n = 9), learning and memory (n = 5), processing of faces (n = 7) and emotional stimuli (n = 8). For papers investigating executive function and selective auditory attention, the most commonly reported measures were alpha power and the amplitude and latency of positive (P1, P2, P3) and negative (N1, N2) deflections of event related potential (ERPs) components. The N170 and P1 ERP components were the most commonly reported neural responses to face and emotional faces stimuli. A mid-latency negative component and positive slow wave were used to index learning and memory, and late positive potential in response to emotional non-face stimuli. While almost half the studies described changes in EEG measures across age, only eight studies disaggregated results based on gender, and six included children from low income households to assess the impact of SES on neurodevelopment. No studies were conducted in low- and middle-income countries.

Conclusion

This review has identified power across the EEG spectrum and ERP components to be the measures most commonly reported in studies in which preschool children engage in tasks indexing cognitive and social development. It has also highlighted the need for additional research into their changes across age and based on gender and SES.

Relations between frontal EEG maturation and inhibitory control in preschool in the prediction of children's early academic skills

Maturation of the prefrontal cortex (PFC) across the first few years of life is thought to underlie the emergence of inhibitory control (IC) abilities, which may play an important role in children's early academic success. In this growth curve modeling study (N = 364), we assessed developmental change in children's resting-state electroencephalogram (EEG) activity (6-9 Hz 'alpha' power) from 10 months to 4 years and examined whether the initial levels or amount of change in frontal alpha power were associated with children's IC at age 4 and indirectly academic skills at age 6. Results indicated that greater increases in frontal alpha power across the study period were associated with better IC, and indirectly with better performance on Woodcock-Johnson tests of reading and math achievement at age 6. Similar associations between change in EEG and age 4 vocabulary were observed but did not mediate an association with academic skills. Similar analyses with posterior alpha power showed no associations with IC. Findings underscore the significance of frontal lobe maturation from infancy to early childhood for children's intellectual development.

The relationship between temperamental dimensions and inhibitory control in early childhood: Implications for language acquisition

The present study investigates the latent organization of inhibitory control in children aged between 2;3 and 3;0 years. In addition, it explores the relationships between temperament dimensions - social orientation, motor activity, and attention -, inhibitory control and language. One-hundred-twelve typically developing children were evaluated with tasks for inhibitory control and lexical skills, while ratings of temperament and language were collected from their caregivers. A Confirmatory Factor Analysis reveals that inhibitory control seems to be best described by a unitary dimension. A Structural Equation Model suggests that 78 % of the variance in vocabulary is explained by a model considering the language observed measures, the three temperamental dimensions, and inhibitory control and in which both temperamental attention and the latent dimension of inhibitory control are significantly related to vocabulary. In addition, inhibitory control does not mediate the relationship between temperament and language.

Inhibitory Control Across the Preschool Years: Developmental Changes and Associations with Parenting

The normative developmental course of inhibitory control between 2.5 and 6.5 years, and associations with maternal and paternal sensitivity and intrusiveness were tested. The sample consisted of 383 children (52.5% boys). During four annual waves, mothers and fathers reported on their children’s inhibitory control using the Children's Behavior Questionnaire. During the first wave, mothers’ and fathers’ sensitivity and intrusiveness were observed and coded with the Emotional Availability Scales. Inhibitory control exhibited partial scalar invariance over time, and increased in a decelerating rate. For both mothers and fathers, higher levels of sensitivity were associated with a higher initial level of children's inhibitory control, whereas higher levels of intrusiveness predicted a slower increase in children's inhibitory control.

Socioeconomic status and executive function in early childhood: Exploring proximal mechanisms

Although there is substantial evidence that socioeconomic status (SES) predicts children's executive function (EF), the mechanisms underlying this association are poorly understood. This study tested the utility of two theories proposed to link SES to children's EF: the family stress model and the family investment model. Data came from the Midwestern Infant Development Study (N = 151). To measure SES, parental education and income were assessed during pregnancy, and income was also assessed when children were 6 and 36 months old. Children's EF, operationalized as working memory/inhibitory control (WMIC) and self-control, was assessed at 36 months of age, along with potential mediators including maternal psychological distress, harsh parenting, and cognitive stimulation. Using structural equation modeling, we tested simultaneous pathways from SES to EF: (a) via maternal psychological distress to harsh parenting (family stress model) and (b) via cognitive stimulation (family investment model). Of the SES measures, lower education predicted poorer WMIC directly and indirectly via greater maternal psychological distress. Lower education also predicted poorer self-control via greater maternal psychological distress. This effect was partially suppressed by an indirect path from lower education to better self-control via greater psychological distress and increased harsh parenting. Cognitive stimulation did not act as a mediator. Income was not directly or indirectly associated with EF. These findings provide partial support for the family stress model and suggest that family functioning is an important proximal mechanism for children's EF development. This study also highlights the importance of considering SES as a multidimensional construct.

Context of Maternal Intrusiveness During Infancy and Associations with Preschool Executive Function

The relation between maternal behavior and neurocognitive development is complex and may depend on the task context. We examined 5-month-old infant frontal EEG, maternal intrusiveness (MI) evaluated during two play contexts at 5 and 10 months, and a battery of executive function (EF) tasks completed at 48 months to evaluate if MI during infancy and infant neural function interacted to predict later cognition. Infant frontal EEG was a predictor of 4-year EF. MI during structured play at both 5 and 10 months predicted preschool EF, and MI during unstructured did not have a main effect on EF but showed a potential moderating effect of infant EEG on later EF. The pattern changed between ages, with MI during structured play at 5 months showing a positive association with age 4 EF, whereas MI during structured play at 10 months had a negative association with age 4 EF. We demonstrate differences in the context of maternal behavior used to predict childhood EF, highlighting the importance of considering parenting context in EF development.

Stroop-like animal size test: Links with child effortful control, personality and problem behavior

This study examined children's performance on the Stroop-like animal size test and its relations to parent-reported temperamental effortful control, personality, and common emotional and behavioral problems in a Russian sample of 5-12-year-olds (N = 202). The animal size test demonstrated a Stroop-like effect for accuracy and response time (RT) in both genders and across all ages. Children's performance on the animal size test considerably improved with age such that older children performed more accurately, were faster and their responses were less variable than younger children's responses. The findings indicated that RT was negatively related to temperamental trait of effortful control and its key components, attention focusing and inhibitory control, whereas RT variability was negatively related to both regulatory traits, effortful control and conscientiousness, and their components. Children's performance on the AST was meaningfully related to hyperactivity-inattention, externalizing behavior and overall level of childhood psychopathology. These findings provide support for the usefulness of the animal size test in the neuropsychological assessment of preschool and school-age children.

Episodic Memory in Middle Childhood: Age, Brain Electrical Activity, and Self-Reported Attention

Middle childhood is a transitional period for episodic memory (EM) performance, as a result of improvements in strategies that are used to encode and retrieve memories. EM is also a skill continually assessed for testing in the school setting. The purpose of this study was to examine EM performance during middle childhood and its relation to individual differences in attentional abilities and in neurophysiological functioning. We examined self-reports of attention at 6, 7 and 8-years of age as well as parietal EEG recorded during baseline, memory task encoding, and memory task retrieval. Results indicate that child self-reports of attention predicted EM performance. Additionally, the difference from baseline to retrieval-related EEG activation contributed variance to EM performance. Results replicate other middle childhood studies showing a positive association between EM performance and attention while also suggesting that parietal EEG yields critical information regarding memory performance.

Semantic future thinking and executive functions at age 4: The moderating role of frontal brain electrical activity

Previous studies provide conflicting results regarding the relation between future thinking and executive functioning during early childhood. Furthermore, little is known of the neural mechanisms involved in future thinking during early childhood. We examined the moderating role of frontal electroencephalogram (EEG) activity on the relation between executive functioning and semantic future thinking performance in a sample of 4-year-old children. Our results suggest that frontal EEG moderates the relation between executive functioning and semantic future thinking performance, but only for medium to high levels of frontal EEG power values. These results provide emerging evidence regarding the role of both executive functioning and frontal brain electrical activity on semantic future thinking in 4-year-olds.

Executive Attention at Eight Years: Concurrent and Longitudinal Predictors and Individual Differences

Executive attention, the attention necessary to reconcile conflict among simultaneous attentional demands, is vital to children's daily lives. This attention develops rapidly as the anterior cingulate cortex and prefrontal areas mature during early and middle childhood. However, the developmental course of executive attention is not uniform amongst children. Therefore, the purpose of this investigation was to examine the role of individual differences in the development of executive attention by exploring the concurrent and longitudinal contributions to its development at 8 years of age. Executive attention was predicted by concurrent measures of frontal electroencephalography, lab-based performance on a conflict task, and parent report of attention. Longitudinally, 8-year-old executive attention, was significantly predicted by a combination of 4-year old frontal activity, conflict task performance, and parent report of attention focusing, but not with an analogous equation replacing attention focusing with attention shifting. Together, data demonstrate individual differences in executive attention.

Neurodevelopmental maturation as a function of irritable temperament: Insights From a Naturalistic Emotional Video Viewing Paradigm

Few studies have investigated the neural systems involved in decreasing behavioral reactivity to emotional stimuli as children age. It has been suggested that this process may interact with temperament-linked variations in neurodevelopment to better explain individual differences in the maturation of emotion regulation. In this investigation, children ages 4 to 12 (n = 30, mean age = 7.62 years, SD = 1.71 years) and adults (n = 21, mean age = 26.67 years) watched clips from popular children's films containing positive, negative, or neutral emotional content during functional magnetic resonance imaging. Compared to adults, children demonstrated greater activation in subcortical and visual regions (hippocampus, thalamus, visual cortex, fusiform) during negative clips and greater activation of subcortical and prefrontal regions during positive clips (hippocampus, thalamus, caudate, ACC, OFC, superior frontal cortex). In children only, we found an age by temperament interaction in frontal and subcortical regions indicating that activation increased as a function of age in the most irritable children, but decreased as a function of age in the least irritable children. Findings were not present in the temperament domain of fear. Findings replicate and extend the existing irritability literature, indicating that healthy children highest in irritability may develop comparatively greater activation of the lateral prefrontal cortex in order to support adaptive regulation during emotional challenges. These results are discussed within the context of the emerging literature on the utility of complex, multidimensional, and naturalistic stimuli, which present a complementary alternative to understanding ecologically valid and sustained neural responses to emotionally evocative stimuli. Hum Brain Mapp 38:5307-5321, 2017. © 2017 Wiley Periodicals, Inc.

Inclusion of a Mixed Condition Makes the Day/Night Task More Analogous to the Adult Stroop

In a study with 4-year-old children, we added a mixed condition to the traditional day/night task to examine performance and response times for congruent and incongruent trials within the same condition. There were no differences in percentage correct performance between the incongruent and mixed conditions; however, children performed best on the congruent condition. EEG recordings showed differential patterns of frontal power and coherence suggesting increasing cognitive load from congruent to incongruent to mixed conditions. Our pattern of findings suggest that the mixed condition of the day/night Stroop task is a more appropriate child equivalent to the adult color-word Stroop task.

Boys with fragile X syndrome: investigating temperament in early childhood

BACKGROUND

Fragile X syndrome (FXS) is an x-linked genetic disorder that represents the most common hereditary cause of Intellectual Disability (ID). Very specific behavioural features (e.g. attention deficit hyperactivity disorder and stereotyped behaviour) are associated with FXS in adolescents and adults, yet research on temperament and behavioural characteristics in young children with FXS has been more limited and less conclusive.

METHOD

This study investigated temperament differences in young boys (3-7 years old) with FXS (N = 26) recruited from a national FXS centre and controls (N = 26) matched on age, gender and race.

RESULTS

Compared with controls, boys with FXS exhibited less overall surgency/extraversion and effortful control. Boys with FXS also displayed significantly greater activity and shyness and less attentional focusing, inhibitory control, soothability and high intensity pleasure (tendency to enjoy intense/complex activities), relative to comparison children. A significant interaction between age and diagnosis (FXS or control) was observed for negative affectivity only.

CONCLUSIONS

Attention difficulties commonly found in adolescents and adults with FXS appear to also be characteristic of young boys with FXS, as reflected by lower effortful control. Age-related findings concerning negative affectivity may be particularly significant, leading to improved intervention/preventative efforts.

The neural substrates of cognitive flexibility are related to individual differences in preschool irritability: A fNIRS investigation

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A novel, child-appropriate, Stroop task was used to assess preschoolers’ cognitive flexibility.

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Cognitive flexibility was linked to increased oxygenated-hemoglobin in the left DLPFC.

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Oxygenated-hemoglobin in the bilateral DLPFC during cognitive flexibility was positively correlated with irritability.

Preschool (age 3–5) is a phase of rapid development in both cognition and emotion, making this a period in which the neurodevelopment of each domain is particularly sensitive to that of the other. During this period, children rapidly learn how to flexibly shift their attention between competing demands and, at the same time, acquire critical emotion regulation skills to respond to negative affective challenges. The integration of cognitive flexibility and individual differences in irritability may be an important developmental process of early childhood maturation. However, at present it is unclear if they share common neural substrates in early childhood. Our main goal was to examine the neural correlates of cognitive flexibility in preschool children and test for associations with irritability. Forty-six preschool aged children completed a novel, child-appropriate, Stroop task while dorsolateral prefrontal cortex (DLPFC) activation was recorded using functional Near Infrared Spectroscopy (fNIRS). Parents rated their child’s irritability. Results indicated that left DLPFC activation was associated with cognitive flexibility and positively correlated with irritability. Right DLPFC activation was also positively correlated with irritability. Results suggest the entwined nature of cognitive and emotional neurodevelopment during a developmental period of rapid and mutual acceleration.

Measuring the development of inhibitory control: The challenge of heterotypic continuity

Inhibitory control is thought to demonstrate heterotypic continuity, in other words, continuity in its purpose or function but changes in its behavioral manifestation over time. This creates major methodological challenges for studying the development of inhibitory control in childhood including construct validity, developmental appropriateness and sensitivity of measures, and longitudinal factorial invariance. We meta-analyzed 198 studies using measures of inhibitory control, a key aspect of self-regulation, to estimate age ranges of usefulness for each measure. The inhibitory control measures showed limited age ranges of usefulness owing to ceiling/floor effects. Tasks were useful, on average, for a developmental span of less than 3 years. This suggests that measuring inhibitory control over longer spans of development may require use of different measures at different time points, seeking to measure heterotypic continuity. We suggest ways to study the development of inhibitory control, with overlapping measurement in a structural equation modeling framework and tests of longitudinal factorial or measurement invariance. However, as valuable as this would be for the area, we also point out that establishing longitudinal factorial invariance is neither sufficient nor necessary for examining developmental change. Any study of developmental change should be guided by theory and construct validity, aiming toward a better empirical and theoretical approach to the selection and combination of measures.

A Longitudinal Investigation of Conflict and Delay Inhibitory Control in Toddlers and Preschoolers

RESEARCH FINDINGS

Eighty-one children participated in a longitudinal investigation of inhibitory control (IC) from 2 to 4 years of age. Child IC was measured via maternal report and laboratory measures under conditions of conflict and delay. Performance on delay IC tasks at 3 years was related to performance on these same tasks at 2 and 4 years, but performance on conflict IC tasks was not related over time. Delay IC task performance was concurrently related to conflict IC task performance in 3- and 4-year-olds but not related in 2-year-olds. Measures of IC varied in their associations with measures of verbal ability and maternal report IC. Such findings highlight important similarities and distinctions between conflict and delay IC abilities in their relation to one another and to temperament and language over time.

PRACTICE OR POLICY

Studies of IC and related concepts reveal that children who are regulated enjoy school more and have higher school competence, particularly in mathematics and reading achievement. Because conflict IC and delay IC show unique patterns of development over time, educators can expect classroom behaviors drawing upon the state-like conflict IC to show more fluctuation over time than those drawing on the trait-like delay IC.

To Stroop or not to Stroop: Sex-related differences in brain-behavior associations during early childhood

Executive functions (EFs) are linked with optimal cognitive and social-emotional development. Despite behavioral evidence of sex differences in early childhood EF, little is known about potential sex differences in corresponding brain-behavior associations. The present study examined changes in 4-year-olds' 6-9 Hz EEG power in response to increased executive processing demands (i.e., "Stroop-like" vs. "non-Stroop" day-night tasks). Although there were no sex differences in task performance, an examination of multiple scalp electrode sites revealed that boys exhibited more widespread changes in EEG power as compared to girls. Further, multiple regression analyses controlling for maternal education and non-EF performance indicated that individual differences in boys' and girls' EF performance were associated with different frontal neural correlates (i.e., different frontal scalp sites and different measures of EEG power). These data reveal valuable information concerning sex differences in the neural systems underlying executive processing during early childhood.

The role of language ability and self-regulation in the development of inattentive-hyperactive behavior problems

Previous research has found associations but not established mechanisms of developmental linkage between language ability and inattentive-hyperactive (I-H) behavior problems. The present study examined whether self-regulation mediates the effect of language ability on later I-H behavior problems among young children (N = 120) assessed at 30, 36, and 42 months of age. Cross-lagged panel models tested the direction of effect between language ability and self-regulation and longitudinal effects of language ability on later I-H problems mediated by self-regulation. Language ability was measured by children's scores on the receptive and expressive language subtests of the Differential Ability Scales. Self-regulation was measured by three behavioral tasks requiring inhibitory control. I-H problems were reported by parents and secondary caregivers. Language ability predicted later self-regulation as measured by all three tasks. There was no association, however, between self-regulation and later language ability, suggesting that the direction of effect was stronger from language ability to later self-regulation. Moreover, the effect of language ability on later I-H behavior problems was mediated by children's self-regulation in one of the tasks (for secondary caregivers' but not parents' ratings). Findings suggest that language deficits may explain later I-H behavior problems via their prediction of poorer self-regulatory skills.

Behavioral inhibition and developmental risk: a dual-processing perspective

Behavioral inhibition (BI) is an early-appearing temperament characterized by strong reactions to novelty. BI shows a good deal of stability over childhood and significantly increases the risk for later diagnosis of social anxiety disorder (SAD). Despite these general patterns, many children with high BI do not go on to develop clinical, or even subclinical, anxiety problems. Therefore, understanding the cognitive and neural bases of individual differences in developmental risk and resilience is of great importance. The present review is focused on the relation of BI to two types of information processing: automatic (novelty detection, attention biases to threat, and incentive processing) and controlled (attention shifting and inhibitory control). We propose three hypothetical models (Top-Down Model of Control; Risk Potentiation Model of Control; and Overgeneralized Control Model) linking these processes to variability in developmental outcomes for BI children. We argue that early BI is associated with an early bias to quickly and preferentially process information associated with motivationally salient cues. When this bias is strong and stable across development, the risk for SAD is increased. Later in development, children with a history of BI tend to display normative levels of performance on controlled attention tasks, but they demonstrate exaggerated neural responses in order to do so, which may further potentiate risk for anxiety-related problems. We conclude by discussing the reviewed studies with reference to the hypothetical models and make suggestions regarding future research and implications for treatment.

Associations between toddler-age communication and kindergarten-age self-regulatory skills

PURPOSE

In this study, the authors aimed at gaining understanding on the associations of different types of early language and communication profiles with later self-regulation skills by using longitudinal data from toddler age to kindergarten age.

METHOD

Children with early language profiles representing expressive delay, broad delay (i.e., expressive, social, and/or symbolic), and typical language development were compared in domains of kindergarten-age executive and regulative skills (attentional/executive functions, regulation of emotions and behavioral activity, and social skills) assessed with parental questionnaires.

RESULTS

Children with delay in toddler-age language development demonstrated poorer kindergarten-age self-regulation skills than children with typical early language development. Broad early language delays were associated with compromised social skills and attentional/executive functions, and early expressive delays were associated with a generally lower level of kindergarten-age executive and regulative skills. Regression analyses showed that both earlier and concurrent language had an effect especially on the attentional/executive functions.

CONCLUSIONS

The findings suggest that different aspects of toddler-age language have differential associations with later self-regulation. Possible mechanisms linking early language development to later self-regulative development are discussed.

What's mom got to do with it? Contributions of maternal executive function and caregiving to the development of executive function across early childhood

Executive functions (EFs; e.g. working memory, inhibitory control) are mediated by the prefrontal cortex and associated with optimal cognitive and socio-emotional development. This study provides the first concurrent analysis of the relative contributions of maternal EF and caregiving to child EF. A group of children and their mothers (n = 62) completed age-appropriate interaction (10, 24, 36 months) and EF tasks (child: 24, 36, and 48 months). Regression analyses revealed that by 36 months of age, maternal EF and negative caregiving behaviors accounted for unique variance in child EF, above and beyond maternal education and child verbal ability. These findings were confirmed when using an early child EF composite-our most reliable measure of EF - and a similar pattern was found when controlling for stability in child EF. Furthermore, there was evidence that maternal EF had significant indirect effects on changes in child EF through maternal caregiving. At 24 months, EF was associated with maternal EF, but not negative caregiving behaviors. Taken together, these findings suggest that links between negative caregiving and child EF are increasingly manifested during early childhood. Although maternal EF and negative caregiving are related, they provide unique information about the development of child EF. A video abstract of this article can be viewed at http://www.youtube.com/watch?v=NPKXFbbrkps.

Brain Electrical Activity of Shy and Non-Shy Preschool-Aged Children during Executive Function Tasks

Psychophysiological and cognitive performance differences exist between shy and non-shy individuals. Neuroimaging studies have shown identifiable differences in task-related cortical functioning between adults with and without sensitivity to social events. The current study compared baseline and task measures of EEG power (6-9 Hz) for 125 shy and non-shy children between the ages of 41-55 months who differed in core executive function (EF) skills. Results indicated an increase in medial frontal EEG power from baseline-to-task for high EF performers (shy and non-shy). Shy/low EF performers also demonstrated this increase, but the non-shy/low EF group did not. For the medial parietal region, only the shy children (high and low EF performers) showed an increase in power from baseline-to-task; and for the shy/high EF group, left hemisphere power was greater than the right during baseline and task. This study is believed to be the first continuous-recording EEG comparison between children who are shy and non-shy in the context of an EF assessment. These findings highlight differences in medial frontal and medial parietal power for children who differ in shyness and EF skills. They also suggest the value of future research examining strong EF skills as protective and regulatory for shy children.

A longitudinal intergenerational analysis of executive functions during early childhood

Despite the importance of executive function (EF) in both clinical and educational contexts, the aetiology of individual differences in early childhood EF remains poorly understood. This study provides the first longitudinal intergenerational analysis of mother-child EF associations during early childhood. A group of children and their mothers (n = 62) completed age-appropriate EF tasks. Mother and child EFs were modestly correlated by 24 months of age, and this association was stable through 48 months. Importantly, maternal-child EF associations were still robust after controlling for verbal ability (potential indicator of verbal/crystallized intelligence) and maternal education (correlate of socio-economic status and verbal intelligence). Potential implications of these findings as well as underlying mechanisms of the maternal-child EF association (gene-environment interplay) are discussed.

Infant attention and early childhood executive function

Individual differences in infant attention are theorized to reflect the speed of information processing and are related to later cognitive abilities (i.e., memory, language, and intelligence). This study provides the first systematic longitudinal analysis of infant attention and early childhood executive function (EF; e.g., working memory, inhibitory control, cognitive flexibility). A group of 5-month-olds (n = 201) were classified as short or long lookers. At 24, 36, and 48 months of age, children completed age-appropriate EF tasks. Infant short lookers (i.e., more efficient information processors) exhibited higher EF throughout early childhood as compared to infant long lookers, even after controlling for verbal ability (a potential indicator of intelligence). These findings are discussed in relation to the emergence of executive attention.

Individual differences in inhibitory control skills at three years of age

Sixty-eight 3-year-old children participated in an investigation of inhibitory control (IC). Child IC was measured using various tasks in order to determine the impact on child performance of manipulating task demands. Performance on a nonverbal IC task, but not performance on more difficult motivational or traditional IC tasks, was explained by medial frontal electroencephalographic activity and by language abilities. Because of the unique relations of nonverbal IC with concurrent developmental measures, and because of its potential to predict later social problems, we conclude that it is important to include nonverbal IC measures in investigative IC batteries in early childhood.

The effect of delayed responding on Stroop-like task performance among preschoolers

Forty-four preschoolers completed 2 conditions of a Stroop-like procedure (e.g., saying "boat" for car and "car" for boat) that differed in whether a 3-s delay was imposed before responding. The test card was visible during the delay period for half of the children and occluded for the other children. Preschoolers' interference control was significantly improved in the delay condition. There was no difference between the two delay variants (test card visible or occluded). Children were more prone to interference as testing progressed regardless of whether the delay was present. These results suggest that delays effectively reduce interference by reducing the potency of the competing response during test trials, although memory demands may moderate the effectiveness of delays.

Using EEG to Study Cognitive Development: Issues and Practices

Developmental research is enhanced by use of multiple methodologies for examining psychological processes. The electroencephalogram (EEG) is an efficient and relatively inexpensive method for the study of developmental changes in brain-behavior relations. In this review, we highlight some of the challenges for using EEG in cognitive development research. We also list best practices for incorporating this methodology into the study of early cognitive processes. Consideration of these issues is critical for making an informed decision regarding implementation of EEG methodology.

The role of anxiety sensitivity, behavioral inhibition, and cognitive biases in anxiety symptoms: structural equation modeling of direct and indirect pathways

OBJECTIVE(S)

Limited research has examined how temperamental (i.e., behavioral inhibition, anxiety sensitivity) and cognitive (i.e., interpretive and judgment biases) risks for the development anxiety covary to influence anxiety symptoms. Thus, the present study aimed to advance understanding of the direct and indirect links between anxiety sensitivity, behavioral inhibition, and interpretive biases, and judgment biases (in the form of perceived control) to anxiety outcomes (i.e., worry and trait anxiety symptoms).

METHOD

842 emerging adults (mean = 18.75 years, standard deviation = 1.05; age range = 18-24; 70% women) recruited from a university in the northeast participated in this study. Participants completed a battery of self-report measures assessing risk factors and anxiety outcomes of interest.

RESULTS

Structural equation modeling revealed anxiety sensitivity and behavioral inhibition were directly linked with anxiety outcomes. Anxiety sensitivity and behavioral inhibition were also indirectly linked with anxiety outcomes through interpretive and judgment biases. The hypothesized model was partially invariant across high-risk and low-risk groups for anxiety disorders.

CONCLUSIONS

Results of this study provide preliminary support for theoretical models hypothesizing a developmental progression from temperamental to cognitive risks and culminating in the expression of anxiety symptoms. Limitations and clinical implications of this research are discussed.

Longitudinal antecedents of executive function in preschoolers

Despite an extensive history underscoring the role of social processes and child contributions to the development of executive functions (C. Lewis & J. Carpendale, 2009; L. S. Vygotsky, 1987), research on these relations is sparse. To address this gap, 68 mother-child dyads were examined to determine whether maternal attention-directing behaviors (attention maintaining, attention redirection) and toddlers' temperament predicted executive processes during preschool (mean age = 4.5 years, SD = 0.46)-delay and conflict inhibition. Maternal attention maintaining was associated with high levels of conflict inhibition for inhibited and exuberant children, whereas attention redirection was associated with low levels of delay and conflict inhibition for inhibited children. Therefore, maternal attention-directing behaviors may enhance the development of executive functions but only for children with inhibited and exuberant temperaments.

Early Childhood Predictors of Post-Kindergarten Executive Function: Behavior, Parent-Report, and Psychophysiology

RESEARCH FINDINGS: This study examined whether children's executive functions before kindergarten would predict variance in executive functions after kindergarten. We obtained behavioral (working memory task performance), parental-reported (temperament-based inhibitory control), and psychophysiological (working memory-related changes in heart rate and brain electrical activity) measures of executive functions from a group of preschool-aged children. After children finished kindergarten, approximately 2 years later, parents were asked to complete an assessment of children's executive function skills. A regression analysis revealed that pre-kindergarten behavioral, parental-reported, and psychophysiological measures accounted for variance in post-kindergarten executive functions. Specifically, working memory task performance, temperament-based inhibitory control, and working memory-related changes in brain electrical activity accounted for unique variance in post-kindergarten executive functions. These data provide a unique contribution to the executive function literature: No other study has examined whether behavioral, psychophysiological, and parental-reported executive function measures can account for unique variance in future executive function. PRACTICE OR POLICY: These findings are discussed in relation to children's transition to school and executive function training programs.

EEG power and coherence during preschoolers' performance of an executive function battery

The current study investigated a set of abilities collectively referred to as executive function (EF). Substantial improvement in EF ability occurs between 3 and 6 years of age (e.g., Carlson [2005] Developmental Neuropsychology, 28(2):595-616). This improvement is thought to reflect changes in brain development, especially in areas of prefrontal cortex and frontal cortex, which occur during this time period (e.g., Luu & Posner [2003] Brain 126:2119-2120). Little work has examined preschoolers' cortical activity during EF tasks, despite the frequent use of performance on such tasks as indirect measures of (pre)frontal functioning. The current study measured continuous EEG activity in 104 preschool aged children as they completed a battery of EF tasks. Changes from baseline to task performance in EEG activity (power, coherence) were used as predictors of EF ability. Results indicated that changes from baseline to task engagement in EEG coherence, but not EEG power, were significantly related to performance on the EF battery in our sample.

Articulation rate and its relationship to disfluency type, duration, and temperament in preschool children who stutter

The purpose of this study was to examine the relationship between articulation rate, frequency and duration of disfluencies of different types, and temperament in preschool children who stutter (CWS). In spontaneous speech samples from 19 CWS (mean age=3:9; years:months), we measured articulation rate, the frequency and duration of (a) sound prolongations; (b) sound-syllable repetitions; (c) single syllable whole word repetitions; and (d) clusters. Temperament was assessed with the Children's Behavior Questionnaire (Rothbart et al., 2001). There was a significant negative correlation between articulation rate and average duration of sound prolongations (p<0.01), and between articulation rate and frequency of stuttering-like disfluencies (SLDs) (p<0.05). No other relationships proved statistically significant. Results do not support models of stuttering development that implicate particular characteristics of temperament as proximal contributors to stuttering; however, this is likely due to the fact that current methods, including the ones used in the present study, do not allow for the identification of a functional relationship between temperament and speech production. Findings do indicate that for some CWS, relatively longer sound prolongations co-occur with relatively slower speech rate, which suggests that sound prolongations, across a range of durations, may represent a distinct type of SLD, not just in their obvious perceptual characteristics, but in their potential influence on overall speech production at multiple levels.

LEARNING OUTCOMES

Readers will be able to describe the relationship between stuttering-like disfluencies, articulation rate and temperament in children who stutter, and discuss different measurements of articulation rate.