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

Executive functioning profiles and mathematical and reading achievement in Grades 2, 6, and 10

Using a person-centered approach, we aimed to identify different executive functioning profiles to assess heterogeneity across individuals within the same school grade through latent profile analysis. A sample of 150 Grade 2 (7-8 years old), 150 Grade 6 (11-12 years old), and 150 Grade 10 (15-16 years old) children and adolescents were assessed on 11 different executive tasks representative of the three main executive functioning subcomponents (i.e., inhibition, cognitive flexibility, and working memory), fluid intelligence, processing speed, problem-solving, and reading comprehension. Three different executive functioning profiles of different patterns of interactions based on inhibition, cognitive flexibility, and working memory within and between grades were identified. Moreover, these profiles were differentially related to reading comprehension and mathematical achievement. Second, as expected, we did not find these profiles to be associated with sociodemographic variables such as chronological age or sex. Still, fluid intelligence and processing speed were differentially related to the different profiles at each grade. We also found that the executive functioning profiles interacted with each cognitive skill (i.e., fluid intelligence and processing speed) in predicting reading comprehension and math achievement. These findings provide valuable insights for developing preventive and intervention strategies in education.

Maturational changes in frontal EEG alpha and theta activity from infancy into early childhood and the relation with self-regulation in boys and girls

There is increasing interest in examining the development of frontal EEG power in relation to self-regulation in early childhood. However, the majority of previous studies solely focuses on the brain's alpha rhythm and little is known about the differences between young boys and girls. The aim of the current study was therefore to gain more insight into the neural mechanisms involved in the emergence of self-regulation. The sample consisted of 442 children and data were collected at approximately 5 months, 10 months, and around 3 years of age. Latent growth curve models indicated that,while the neurobiological foundations of self-regulation are established during infancy,it is the maturation of the frontal alpha rhythm that contributes to variations in both observed and parent-reported self-regulation. In addition, it appears that boys might have a greater reliance on external regulation than girls during early childhood, as evident by higher scores of girls on both measures of self-regulation. More insight into the role of external regulators in brain maturation can help to implement interventions aimed at establishing bottom-up self-regulatory skills early in life, in order to provide the necessary foundations for the emergence of top-down self-regulatory skills in the preschool period.

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.

Examining normative values using the Cambridge neuropsychological test automated battery and developmental traits of executive functions among elementary school-aged children in Japan

The Cambridge Neuropsychological Test Automated Battery (CANTAB) is a computerized and child-friendly neuropsychological assessment battery that includes subtests aimed at evaluating some aspects of executive functions. Using the CANTAB, this study aims to establish normative values based on the aspects of executive functions among school-aged children in Japan. The participants included 234 children (135 boys and 99 girls aged 6-12 years) enrolled in regular classes, without any clinical records of developmental disorders or educational support. The participants were grouped according to age (6-7, 8-9, and 10-12 years). Four CANTAB subtests, including spatial working memory (SWM) to assess spatial working memory, Stockings of Cambridge (SOC) to evaluate planning, intra/extradimensional set shift (IED) to evaluate attentional set shifting and flexibility, and stop signal task (SST) to evaluate inhibition, were administered to each participant. The results showed that performance in all the CANTAB subtests administered changed with age. Among the subtests, compared with performances in the SOC and IED, those in the SWM and SST improved earlier, thereby indicating that spatial working memory and inhibition develop earlier than planning as well as attentional set shifting and flexibility. Additionally, in the SST subtest, girls made fewer errors than boys did in the 6-7 years group. This study presents normative data of four CANTAB subtests according to age and sex among school-aged children in Japan. We expect that the findings will be used to develop effective tools for the early detection of and support for children with executive dysfunction.

Functional connectivity analysis of childhood depressive symptoms

BACKGROUND

Childhood depression is a highly distinct and prevalent condition with an unknown neurobiological basis. We wish to explore the resting state fMRI data in children for potential associations between neural connectivity and childhood depressive symptoms.

METHODS

A longitudinal birth cohort study with neuroimaging data obtained at 4.5, 6.0 and 7.5 years of age and the Children Depression Inventory 2 (CDI) administered between 8.5 and 10.5 years was used. The CDI score was used as the dependent variable and tested for correlation, both simple Pearson and network based statistic, with the functional connectivity values obtained from the resting state fMRI. Cross-validated permutation testing with a general linear model was used to validate that the identified functional connections were indeed implicated in childhood depression.

RESULTS

Ten functional connections and four brain regions (Somatomotor Area B, Temporoparietal Junction, Orbitofrontal Cortex and Insula) were identified as significantly associated with childhood depressive symptoms for girls at 6.0 and 7.5 years. No significant functional connections were found in girls at 4.5 years or for boys at any timepoint. Network based statistic and permutation testing confirmed these findings.

CONCLUSIONS

This study revealed significant sex-dependent associations of neural connectivity and childhood depressive symptoms. The regions identified are implicated in speech/language, social cognition and information integration and suggest unique pathways to childhood depressive symptoms.

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.

Seeing and looking: Evidence for developmental and stimulus-dependent changes in infant scanning efficiency

Though previous work has examined infant attention across a variety of tasks, less is known about the individual saccades and fixations that make up each bout of attention, and how individual differences in saccade and fixation patterns (i.e., scanning efficiency) change with development, scene content and perceptual load. To address this, infants between the ages of 5 and 11 months were assessed longitudinally (Experiment 1) and cross-sectionally (Experiment 2). Scanning efficiency (fixation duration, saccade rate, saccade amplitude, and saccade velocity) was assessed while infants viewed six quasi-naturalistic scenes that varied in content (social or non-social) and scene complexity (3, 6 or 9 people/objects). Results from Experiment 1 revealed moderate to strong stability of individual differences in saccade rate, mean fixation duration, and saccade amplitude, and both experiments revealed 5-month-old infants to make larger, faster, and more frequent saccades than older infants. Scanning efficiency was assessed as the relation between fixation duration and saccade amplitude, and results revealed 11-month-olds to have high scanning efficiency across all scenes. However, scanning efficiency also varied with scene content, such that all infants showing higher scanning efficiency when viewing social scenes, and more complex scenes. These results suggest both developmental and stimulus-dependent changes in scanning efficiency, and further highlight the use of saccade and fixation metrics as a sensitive indicator of cognitive processing.

Association between carotid atherosclerosis and brain activation patterns during the Stroop task in older adults: An fNIRS investigation

There is an increasing body of evidence suggesting that vascular disease could contribute to cognitive decline and overt dementia. Of particular interest is atherosclerosis, as it is not only associated with dementia, but could be a potential mechanism through which cardiovascular disease directly impacts brain health. In this work, we evaluated the differences in functional near infrared spectroscopy (fNIRS)-based measures of brain activation, task performance, and the change in central hemodynamics (mean arterial pressure (MAP) and heart rate (HR)) during a Stroop color-word task in individuals with atherosclerosis, defined as bilateral carotid plaques (n = 33) and healthy age-matched controls (n = 33). In the healthy control group, the left prefrontal cortex (LPFC) was the only region showing evidence of activation when comparing the incongruous with the nominal Stroop test. A smaller extent of brain activation was observed in the Plaque group compared with the healthy controls (1) globally, as measured by oxygenated hemoglobin (p = 0.036) and (2) in the LPFC (p = 0.02) and left sensorimotor cortices (LMC)(p = 0.008) as measured by deoxygenated hemoglobin. There were no significant differences in HR, MAP, or task performance (both in terms of the time required to complete the task and number of errors made) between Plaque and control groups. These results suggest that carotid atherosclerosis is associated with altered functional brain activation patterns despite no evidence of impaired performance of the Stroop task or central hemodynamic changes.

Inhibitory abilities in girls and boys: More similarities or differences?

This brief review examined the literature from 1990 to June 2020 on sex differences in inhibitory abilities from early childhood to adolescence, primarily in individuals with typical development (TD) and individuals with atypical development. The 38 articles included (28 on individuals with TD, eight on the attention deficit hyperactivity disorder [ADHD] population, and two on individuals with autism spectrum disorder [ASD]) suggest that the cognitive demand of the task is important, together with contextual factors that may interact with the development of inhibitory ability, for revealing differences between the sexes. The literature has neglected the multicomponential nature of inhibitory abilities, and the emphasis has consequently been placed on response inhibition (vs. other components). The implication of the impurity problem has also been considered. The findings on children and adolescents with ADHD or ASD-even for outcomes that are not conclusive-imply that there is no evidence for a difference in inhibitory abilities between males and females. The literature proposes an asynchrony in the development of inhibitory abilities that may explain what is found in typically developing girls who perform more highly than boys on more demanding tasks.

Context matters: Cortical rhythms in infants across baseline and play

This study uses electroencephalography (EEG) to examine infants' cortical activity during baseline while they watched a dynamic audiovisual display and while engaged in play with an object and parent. Fifty-five 6- to 12-month-old infants participated in both baseline and play with their mother. We hypothesized that the baseline task recruits relatively more exogenous attention due to the dynamic audiovisual task, while the play task recruits relatively more endogenous attention when exploring the toy. We expected higher frontal theta and alpha power during play, reflecting higher endogenous control of attention compared to the baseline task. We expected the faster rhythms, beta and gamma, to have higher power during baseline at frontal locations, reflecting the salient attention-grabbing (exogenous) attributes of the baseline task in comparison to play. We also examined changes in parietal power between contexts. Our results were consistent with the expectations. Theta (3-6 Hz) and alpha (6-9 Hz) power were higher at frontal sites (Fp1/Fp2) during play relative to baseline. Beta (9-30 Hz) and gamma (30-50 Hz) power were higher at frontal (Fp1/Fp2) and frontal medial sites (F3/F4) during baseline relative to play. Alpha power was higher during baseline at frontal medial sites (F3/F4) relative to play. Beta and gamma power was higher during play at parietal sites (P3/P4). The results are discussed in terms of the potential role of different cortical rhythms over the scalp as they respond to relative endogenous and exogenous attentional demands.

The effects of reward on children's Stroop performance: Interactions with temperament

The effects of rewards on executive function (EF) reflect bidirectional interactions among motivational and executive systems that vary with age and temperament. However, methodological limitations hinder understanding of the precise influences of incentives on early EF, including the role of reward sensitivity. In this within-subjects study, ninety-three 3.5- to 5-year-olds (42 girls; 22% Hispanic; 78% White) residing in the United States completed equivalent EF measures (Stroop and non-Stroop phases) in both rewarded and non-rewarded conditions. Rewards enhanced Stroop accuracy and slowed overall response times (ds = 0.29-0.40). Critically, children with low parent-reported reward sensitivity exhibited greater reward-based increases in Stroop accuracy (r = -.30). These findings provide valuable insights on early motivation-cognition integration, highlighting temperament as a mechanism underlying these interactions.

Infant electroencephalogram coherence and early childhood inhibitory control: Foundations for social cognition in late childhood

Social cognition is a set of complex processes that mediate much of human behavior. The development of these skills is related to and interdependent on other cognitive processes, particularly inhibitory control. Brain regions associated with inhibitory control and social cognition overlap functionally and structurally, especially with respect to frontal brain areas. We proposed that the neural foundations of inhibitory control and social cognition are measurable in infancy. We used structural equation modeling and showed that 10-month frontotemporal neuroconnectivity measured using electroencephalogram coherence predicts social cognition at 9 years of age through age-4 inhibitory control. These findings provide insight into the neurodevelopmental trajectory of cognition and suggest that connectivity from frontal regions to other parts of the brain is a foundation for the development of these skills. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

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.

Are there sex differences in the development of prefrontal function during early childhood?

Research has demonstrated the possibility of minor sex differences in executive function (EF) development of young children; however, this may be limited to the measurements used in previous studies (questionnaires and cognitive tasks), which tend to be less sensitive to the detection of sex differences. The present study uses brain measures to examine the effect of sex on EF development. In this study, preschool children were given an EF task, and patterns of activation in the lateral prefrontal regions were measured by a functional near-infrared spectroscopy. In Study 1, there were no behavioral differences between girls and boys, though girls showed stronger prefrontal activation than boys. Study 2 was conducted as an attempt to replicate the results, and some of the results were inconsistent with the results in Study 1. Results suggest that sex differences in EF tasks are small, although such differences may exist irrespective of methodology.

Shyness, Self-regulation, and Cognitive Problem Solving in Typically Developing 4-year-olds: A Pilot Study

Because shy children are at risk for poor academic achievement, it is important to examine factors that contribute to variability in the relation between individual differences in shyness and cognitive functioning before school entry. The authors examined whether on-task facilitative private speech-a proxy of self-regulation-moderated the association between individual differences in shyness and performance on an executive function (EF) task in 52 typically developing 4-year-olds. They found that private speech interacted with shyness to predict performance on the EF task in girls but not in boys. More specifically, shyness was inversely related to EF task performance when girls used low amounts of regulatory private speech, but was positively related to performance when girls used high amounts of regulatory private speech. These preliminary findings are discussed in the context of implications for shy children in educational settings.

Gamma power in rural Pakistani children: Links to executive function and verbal ability

Children in low- and middle-income countries are at high risk of cognitive deficits due to environmental deprivation that compromises brain development. Despite the high prevalence of unrealized cognitive potential, very little is known about neural correlates of cognition in this population. We assessed resting EEG power and cognitive ability in 105 highly disadvantaged 48-month-old children in rural Pakistan. An increase in EEG power in gamma frequency bands (21-30Hz and 31-45Hz) was associated with better executive function. For girls, EEG gamma power also related to higher verbal IQ. This study identifies EEG gamma power as a neural marker of cognitive function in disadvantaged children in low- and middle-income countries. Elevated gamma power may be a particularly important protective factor for girls, who may experience greater deprivation due to gender inequality.

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.

Diversity and representation: Key issues for psychophysiological science

This Special Issue is devoted to the illustration and discussion of three key demographic variables (sex/gender, race/ethnicity, and socioeconomic status) that have been shown to moderate associations between psychophysiological processes and behavior. The introduction to the issue discusses the role of phenotypic plasticity in the emergence of different neural processes that achieve the same behavioral outcome, with emphasis on how these relatively stable developmental contexts affect brain/behavior associations without necessarily resulting in difference in behavior. These findings have profound significance for the implications of generalization and call into question the presumption that diverse samples produce an average result that is appropriately reflective of the individuals themselves. Increasing diversity within psychophysiological research is critical in elucidating mechanisms by which the human brain can accomplish cognitive and affective behaviors. This article further examines the logistical and ethical challenges faced in achieving this goal.