Prefrontal Activation During Executive Tasks Emerges Over Early Childhood: Evidence From Functional Near Infrared Spectroscopy

Are there associations between sedentary time inside and outside preschools with preschoolers' executive function?

Preschool children spend a large part of their day at school, and a large part of that time they spend in sedentary time. Although sedentary time negatively affects regions of the brain responsible for cognition, it is believed that the type of sedentary time performed can favor executive functions' performance. The present study explored the associations between sedentary time inside and outside preschools with executive function (EF) tasks in preschoolers. Seventy-three preschool children (60% girls; 55.0 ± 9.1 months of age) were objectively assessed for sedentary time and physical activity (PA) using accelerometers (wGT3X). EF was evaluated using the Go/No-Go paradigm through the Early Years Toolbox - YET. Go's inverse efficiency (IE) and the No-Go accuracy were analyzed. To establish possible associations between EF and sedentary time, a structural equation model was conducted after adjustments for sex, age, body mass index, and moderate-to-vigorous PA. A significant and positive association between sedentary time on weekend days and IE (b = 0.61; p < .001) was observed. The general model explained 52% of the variation in IE and 2.1% in the accuracy of No-Go. The sedentary time on weekend days seems to be related to worse EI. This result emphasizes a context-dependent association between time being sedentary and preschoolers' EF. Further investigations should focus on exploring the type of sedentary behavior children are engaged in different contexts.

Biological, behavioral, and social correlates of executive function in low-income preschoolers: Insights from the perspective of the networks

Behavioral, biological, and social correlates may be related to the association between executive function (EF) and physical activity (PA), when considering such variables as an integrated and non-linear system. Thus, the aim of the present study was to investigate the relationships between EF, PA and associated correlates in low-income preschoolers according to a network perspective. Thus, 142 preschoolers of both sexes, age 3-to-5-years-old (51% girls) were analyzed. Light, moderate and vigorous PA, cardiorespiratory fitness (CRF), body mass index, family income, preterm birth, presence of siblings, presence of other children at home and the child's primary caregiver were assessed. Our results showed that EF was positively associated with age (b = 0.47), child's primary caregivers (b = 0.37), moderate PA (b = 0.30) and CRF (b = 0.25). Negative associations were seen with preterm birth (b = -0.50), vigorous PA (b = -0.34), presence of other children at home (b = -0.25), and sex (b = -0.33). The network's centrality indicators highlighted preterm birth and moderate PA as the most important variables in the network. Future interventions aiming to increase low-income preschoolers' EF should focus on increasing moderate PA, with special attention to preterm children.

Executive control of freestyle skiing aerials athletes in different training conditions

Introduction

Due to the actual limitation of training conditions, the freestyle skiing aerials winter training term is short. Training tasks such as adaptability training and developing new skills are needed in summer training. When facing different training environments, freestyle skiing aerial athletes’ executive control over their abilities could be affected, which can affect their performance. Therefore, we want to research the effect of training conditions on executive control in freestyle skiing aerials athletes and its neural mechanism.

Materials and methods

Thirty-two freestyle skiing aerials athletes were recruited. We evaluated their executive control and used fNIRS to measure oxygenated hemoglobin concentration changes in the prefrontal cortex during a rapid event-related design go/nogo task with different training condition-activated materials.

Results

Athletes’ behavior control in the summer condition has a lower accuracy than it is in the control condition. Athletes’ behavior control in the summer and winter training conditions had a longer reaction time than that in the control condition. The activation of the bilateral dlPFC and orbitofrontal cortex had a significant main effect across training conditions when freestyle skiing aerial athletes completed executive control tasks. The activation of athletes’ bilateral vlPFC and left dlPFC had an interaction between training conditions and behavioral control.

Conclusion

Different training conditions can lead to freestyle skiing aerial athletes executive control ability to drop, players in different training conditions show less activation on both sides of the vlPFC and orbitofrontal. The bilateral vlPFC and left dlPFC have an integrated effect on behavior inhibition across training conditions.

Enhancing Chinese preschoolers' executive function via mindfulness training: An fNIRS study

Mindfulness training has been found to enable cognitive and emotional awareness and diminish emotional distraction and cognitive rigidity. However, the existing intervention studies have largely focused on school children, adolescents, and adults, leaving young children unexplored. This study examined the influence of mindfulness training on young children using the one-group pretest-posttest design. Altogether 31 Chinese preschoolers (M age = 67.03 months, SD = 4.25) enrolled in a 5-week, twice-per-week mindfulness training. Their cognitive shifting, inhibitory control, and working memory were examined using a battery of executive function tasks. And their brain activations in the region of interest during the tasks were measured using fNIRS before and after the intervention. Results showed that their cognitive shifting and working memory tasks performance significantly improved, and their activation in the DLPFC significantly changed. Implications for this study were also included.

Why are some inhibitory tasks easy for preschool children when most are difficult? Testing two hypotheses

Understanding the processes that create inhibitory demands is central to understanding the role of inhibitory control in all aspects of development. The processes that create inhibitory demands on most developmental tasks seem clear and well understood. However, there is one inhibitory task that appears substantially easier than the others: the Reverse Categorization task, in which children are asked to "reverse sort" items (e.g., put large items in a small box and put small items in a large box). This finding is both surprising and problematic because it cannot be explained by any existing account of inhibitory development. Four experiments with 3- and 4-year-olds sought to explain why the Reverse Categorization task is easy. Two experiments (N = 64) investigated the hypothesis that children conceptualize the task in a way that reduces its inhibitory demands; and two experiments (N = 56) tested the hypothesis that the task is easier because children sort items slowly. The data indicate that children spontaneously respond more slowly on the Reverse Categorization task than on other inhibitory tasks and that this slowing reduces the task's cognitive demands. The way in which slowed responding works, and its relation to other inhibition-reducing interventions, is discussed.

Teacher-Rated Executive Functions, Gender and Relative Age: Independent and Interactive Effects on Observed Fundamental Motor Skills in Kindergarteners

Fundamental motor skills (FMS) of children can be affected by different variables, such as executive functions (EF), gender and relative age. However, the effects of these variables on FMS have been scarce studied, especially in early childhood, and show inconsistent results. To clarify these relationships, this study was carried out. Its aim was to analyze whether EF, gender and relative age influenced FMS in 43 Spanish kindergarteners. A multimethod and mixed methods approach was used. Kindergarteners' teachers completed the Childhood Executive Functioning Inventory to know the children level of EF (working memory and inhibition control). Kindergarteners' parents complimented ad hoc questionnaire reporting the children gender and birth data (to know their relative age). A Nomothetic/Punctual/Multidimensional observational design was used to observe children FMS in their habitual motor sessions at school. Two-way ANOVAs were performed to know the independent and interactive effects of working memory level (lower/higher), inhibition control level (lower/higher), gender (boys/girls) and relative age (according to the birth semester in the year) on FMS. Results showed these variables have independent and interactive effects on some FMS, but not on others. FMS influenced by these variables vary depending what independent variable(s) is/are considered. Therefore, it can be concluded that the influences of teacher-rated EF, gender and relative age on observed FMS in kindergarteners are complex and specific. Results obtained must be taken into to design and implement instructional and intervention strategies, as well as educational and sport policy changes, especially in early childhood, when FMS are more malleable.

Links between socioeconomic disadvantage, neural function, and working memory in early childhood

Children reared in socioeconomically disadvantaged environments are at risk for academic, cognitive, and behavioral problems. Mounting evidence suggests that childhood adversities, encountered at disproportionate rates in contexts of socioeconomic risk, shape the developing brain in ways that explain disparities. Circuitries that subserve neurocognitive functions related to memory, attention, and cognitive control are especially affected. However, most work showing altered neural function has focused on middle childhood and adolescence. Understanding alterations in brain development during foundational points in early childhood is a key next step. To address this gap, we examined functional near-infrared-spectroscopy-based neural activation during a working memory (WM) task in young children aged 4-7 years (N = 30) who varied in socioeconomic risk exposure. Children who experienced greater disadvantage (lower income to needs ratio and lower Hollingshead index) exhibited lower activation in the lateral prefrontal cortex than children who experienced less to no disadvantage. Variability in prefrontal cortex activation, but not behavioral performance on the WM task, was associated with worse executive functioning in children as reported by parents. These findings add to existing evidence that exposure to early adversity, such as socioeconomic risk, may lead to foundational changes in the developing brain, which increases risk for disparities in functioning across multiple cognitive and social domains.

An optical window into brain function in children and adolescents: A systematic review of functional near-infrared spectroscopy studies

Despite decades of research, our understanding of functional brain development throughout childhood and adolescence remains limited due to the challenges posed by certain neuroimaging modalities. Recently, there has been a growing interest in using functional near-infrared spectroscopy (fNIRS) to elucidate the neural basis of cognitive and socioemotional development and identify the factors shaping these types of development. This article, focusing on the fNIRS methods, presents an up-to-date systematic review of fNIRS studies addressing the effects of age and other factors on brain functions in children and adolescents. Literature searches were conducted using PubMed and PsycINFO. A total of 79 fNIRS studies involving healthy individuals aged 3-17 years that were published in peer-reviewed journals in English before July 2020 were included. Six methodological aspects of these studies were evaluated, including the research design, experimental paradigm, fNIRS measurement, data preprocessing, statistical analysis, and result presentation. The risk of bias, such as selective outcome reporting, was assessed throughout the review. A qualitative synthesis of study findings in terms of the factor effects on changes in oxyhemoglobin concentration was also performed. This unregistered review highlights the strengths and limitations of the existing literature and suggests directions for future research to facilitate the improved use of fNIRS in developmental cognitive neuroscience research.

A Network Perspective on the Relationship between Screen Time, Executive Function, and Fundamental Motor Skills among Preschoolers

The present study aimed to analyze the dynamic and nonlinear association between screen time, executive function (EF), and fundamental motor skills (FMS) in preschoolers, considering sex and body mass index (BMI) from a network perspective. Forty-two preschoolers (24 boys, 3.91 ± 0.77 years old) provided screen time, EF, FMS, and BMI data. EF was measured using the Go/No Go task, and accuracy of Go (sustain attention), reaction time of Go, and accuracy of No Go (inhibitory control) were considered. Relationships between screen time, EF, FMS, sex, and BMI were explored using a network analysis. The emerged network highlights that screen time is intensely associated with the other variables in the network, while the accuracy of Go has the greater connectivity with other nodes in the network (2.27), being the most sensitive to potential intervention changes. Moreover, sex (1.74), screen time (0.93), and accuracy of Go (0.71) showed the greatest closeness. This study showed that in the emerged network, independent of sex, screen exposure affects the accuracy on Go task, and these components affect the variables in the network, as motor abilities and tasks involved in inhibitory control.

24-hour movement behaviour and executive function in preschoolers: A compositional and isotemporal reallocation analysis

Adherence to healthy behaviours promotes several health benefits in preschool children, including executive function (EF). Recently, the predictive power of the 24-hour movement behaviour (24 h MB) composition on health outcomes has been evidenced; however, its relationship with EF in preschoolers is unknown. Thus, the present study had two objectives: (1) to analyse the associations between the 24 h MB composition and EF of preschoolers; and (2) to investigate the theoretical changes in EF when time in different movement behaviours is reallocated. This cross-sectional study was carried out with 123 preschoolers (3-5 years old) of low socioeconomic status. Physical activity (PA) and sedentary behaviour were assessed using an accelerometer for 7 days, sleep time was obtained through interviews with parents, and EF was measured using the Early Tool Box battery. To verify the association between 24 h MB and EF, compositional data analysis was used, and for time reallocation, compositional isotemporal substitution analysis was utilized. It was observed that the 24 h MB composition was positively associated with EF (p < .0001; R² = 0.34), and that reallocating 5, 10, 15 or 20 min of the time spent on sleep and light PA to moderate-to-vigorous PA, respectively, was associated with significant improvements in EF (p < .05). These findings provide hitherto unseen insight into the relationship between 24 h MB and EF in preschool children, and warrants consideration for researchers and practitioners seeking to improve EF and PA in preschool children.

Cognitive and neural underpinnings of goal maintenance in young children

Active maintenance of goal representations is an integral part of our mental regulatory processes. Previous developmental studies have highlighted goal neglect, which is the phenomenon caused by a failure to maintain goal representations, and demonstrated developmental changes of the ability to maintain goal representations among preschoolers. Yet, few studies have explored the cognitive mechanisms underlying preschoolers' development of goal maintenance. The first aim of this study was to test whether working memory capacity and inhibitory control contribute to goal maintenance using a paradigm for measuring goal neglect. Moreover, although recent studies have shown that preschoolers recruit lateral prefrontal regions in performing executive functions tasks, they could not specify the neural underpinnings of goal maintenance. Thus, the second aim was to examine whether lateral prefrontal regions played a key role in maintaining goal representations using functional near-infrared spectroscopy. Our results showed that developmental differences in inhibitory control predicted the degree of goal neglect. It was also demonstrated that activation in the right prefrontal region was associated with children's successful avoidance of goal neglect. These findings offer important insights into the cognitive and neural underpinnings of goal maintenance in preschoolers.

Functional near-infrared spectroscopy detects increased activation of the brain frontal-parietal network in youth with type 1 diabetes

When considered as a group, children with type 1 diabetes have subtle cognitive deficits relative to neurotypical controls. However, the neural correlates of these differences remain poorly understood. Using functional near-infrared spectroscopy (fNIRS), we investigated the brain functional activations of young adolescents (19 individuals with type 1 diabetes, 18 healthy controls, ages 8-16 years) during a Go/No-Go response inhibition task. Both cohorts had the same performance on the task, but the individuals with type 1 diabetes subjects had higher activations in a frontal-parietal network including the bilateral supramarginal gyri and bilateral rostrolateral prefrontal cortices. The activations in these regions were positively correlated with fewer parent-reported conduct problems (ie, lower Conduct Problem scores) on the Behavioral Assessment System for Children, Second Edition. Lower Conduct Problem scores are characteristic of less rule-breaking behavior suggesting a link between this brain network and better self-control. These findings are consistent with a large functional magnetic resonance imaging (fMRI) study of children with type 1 diabetes using completely different participants. Perhaps surprisingly, the between-group activation results from fNIRS were statistically stronger than the results using fMRI. This pilot study is the first fNIRS investigation of executive function for individuals with type 1 diabetes. The results suggest that fNIRS is a promising functional neuroimaging resource for detecting the brain correlates of behavior in the pediatric clinic.

Novel imaging technologies for genetic diagnoses in the inborn errors of metabolism

Many inborn errors of metabolism and genetic disorders affect the brain. The brain biochemistry may differ from that in the periphery and is not accessible by simple blood and urine sampling. Therefore, neuroimaging has proven to be a valuable tool to not only evaluate the brain structure, but also biochemistry, blood flow and function. Neuroimaging in patients with inborn errors of metabolism can include additional sequences in addition to T1 and T2-weighted imaging because in early stages, there may be no significant findings on the routine sequnces due to the lack of sensitivity or the evolution of abnormalities lags behind the ability of the imaging to detect it. In addition, findings on T1 and T2-weighted imaging of several inborn errors of metabolism may be non-specific and be seen in other non-genetic conditions. Therefore, additional neuroimaging modalities that have been employed including diffusion tensor imaging (DTI), magnetic resonance spectroscopy, functional MRI (fMRI), functional near infrared spectroscopy (fNIRS), or positron emission tomography (PET) imaging may further inform underlying changes in myelination, biochemistry, and functional connectivity. The use of Magnetic Resonance Spectroscopy in certain disorders may add a level of specificity depending upon the metabolite levels that are abnormal, as well as provide information about the process of brain injury (i.e., white matter, gray matter, energy deficiency, toxic buildup or depletion of key metabolites). It is even more challenging to understand how genetic or metabolic disorders contribute to short and/or long term changes in cognition which represent the downstream effects of IEMs. In order to image “cognition” or the downstream effects of a metabolic disorder on domains of brain function, more advanced techniques are required to analyze underlying fiber tracts or alternatively, methods such as fMRI enable generation of brain activation maps after both task based and resting state conditions. DTI can be used to look at changes in white matter tracks. Each imaging modality can explore an important aspect of the anatomy, physiology or biochemisty of the central nervous system. Their properties, pros and cons are discussed in this article. These imaging modalities will be discussed in the context of several inborn errors of metabolism including Galactosemia, Phenylketonruia, Maple syrup urine disease, Methylmalonic acidemia, Niemann-Pick Disease, type C1, Krabbe Disease, Ornithine transcarbamylase deficiency, Sjogren Larsson syndrome, Pelizeaus-Merzbacher disease, Pyruvate dehydrogenase deficiency, Nonketotic Hyperglycinemia and Fabry disease. Space constraints do not allow mention of all the disorders in which one of these modalities has been investigated, or where it would add value to diagnosis or disease progression.

DHEAS and Human Development: An Evolutionary Perspective

Adrenarche, the post-natal rise of DHEA and DHEAS, is unique to humans and the African Apes. Recent findings have linked DHEA in humans to the development of the left dorsolateral prefrontal cortex (LDPFC) between the ages of 4-8 years and the right temporoparietal junction (rTPJ) from 7 to 12 years of age. Given the association of the LDLPFC with the 5-to-8 transition and the rTPJ with mentalizing during middle childhood DHEA may have played an important role in the evolution of the human brain. I argue that increasing protein in the diet over the course of human evolution not only increased levels of DHEAS, but linked meat consumption with brain development during the important 5- to-8 transition. Consumption of animal protein has been associated with IGF-1, implicated in the development of the adrenal zona reticularis (ZR), the site of DHEAS production. In humans and chimps, the zona reticularis emerges at 3-4 years, along with the onset of DHEA/S production. For chimps this coincides with weaning and peak synaptogenesis. Among humans, weaning is completed around 2 ½ years, while synaptogenesis peaks around 5 years. Thus, in chimpanzees, early cortical maturation is tied to the mother; in humans it may be associated with post-weaning provisioning by others. I call for further research on adrenarche among the African apes as a critical comparison to humans. I also suggest research in subsistence populations to establish the role of nutrition and energetics in the timing of adrenarche and the onset of middle childhood.

Neural substrates of early executive function development

In the last decade, advances in neuroimaging technologies have given rise to a large number of research studies that investigate the neural underpinnings of executive function (EF). EF has long been associated with the prefrontal cortex (PFC) and involves both a unified, general element, as well as the distinct, separable elements of working memory, inhibitory control and set shifting. We will highlight the value of utilising advances in neuroimaging techniques to uncover answers to some of the most pressing questions in the field of early EF development. First, this review will explore the development and neural substrates of each element of EF. Second, the structural, anatomical and biochemical changes that occur in the PFC during infancy and throughout childhood will be examined, in order to address the importance of these changes for the development of EF. Third, the importance of connectivity between regions of the PFC and other brain areas in EF development is reviewed. Finally, throughout this review more recent developments in neuroimaging techniques will be addressed, alongside the implications for further elucidating the neural substrates of early EF development in the future.

Functional near-infrared spectroscopy in the evaluation of urban rail transit drivers' mental workload under simulated driving conditions

The objective of this study is to investigate the potential of functional near-infrared spectroscopy (fNIRS) combined with heart rate variability indices, for the evaluation of the mental workload of urban rail transit drivers under simulated driving conditions, particularly during task engagement and disengagement. Experienced metro drivers wearing fNIRS monitoring systems were asked to drive for 90 min in a professional metro driving simulator. Workload stimulus tasks were added and an n-back task (n = 3) was implemented to induce workload in the simulated driving experiment. Experimental results indicate that fNIRS are sensitive to mental workload and reliable for discriminating the degree of mental workload. Research findings demonstrate the feasibility and reliability of fNIRS as a tool for real-time evaluating and monitoring driver mental workload along with task factors from a perspective of brain activations during simulated or actual driving. Practitioner Summary: This study provides evidence for the potential of functional near-infrared spectroscopy (fNIRS) for the evaluation of the mental workload of urban rail transit drivers under simulated driving conditions. The first fNIRS application to mental workload evaluation in the field of urban rail transportation helps companies develop reasonable shiftwork schedule and ensure operation safety. Abbreviations: fNIRS: functional near-infrared spectroscopy; oxy-Hb: Oxy-hemoglobin; NASA-TLX: National Aeronautics and Space Administration Task Load Index; EEG: electroencephalogram; ECG: electrocardiogram; HRV: variability; LF: low-frequency power; HF: high-frequency power; PFC: prefrontal cortex; NIRS: near-infrared spectroscopy; DWT: discrete wavelet transform; EMG: electromyography; DT: determination test; TP: total power; LF_norm: standardized LF; HF_norm: standardized HF; VLF: very low frequency; deoxy-Hb: deoxy-hemoglobin.