Physical activity, aerobic fitness, and brain white matter: Their role for executive functions in adolescence

More similarity than difference: comparison of within- and between-sex variance in early adolescent brain structure

Background

Adolescent neuroimaging studies of sex differences in the human brain predominantly examine mean differences between males and females. This focus on between-groups differences without probing relative distributions and similarities may contribute to both conflation and overestimation of sex differences and sexual dimorphism in the developing human brain.

Methods

We aimed to characterize the variance in brain macro- and micro-structure in early adolescence as it pertains to sex at birth using a large sample of 9-11 year-olds from the Adolescent Brain Cognitive Development (ABCD) Study (N=7,723). Specifically, for global and regional estimates of gray and white matter volume, cortical thickness, and white matter microstructure (i.e., fractional anisotropy and mean diffusivity), we examined: within- and between-sex variance, overlap between male and female distributions, inhomogeneity of variance via the Fligner-Killeen test, and an analysis of similarities (ANOSIM). For completeness, we examined these sex differences using both uncorrected (raw) brain estimates and residualized brain estimates after using mixed-effects modeling to account for age, pubertal development, socioeconomic status, race, ethnicity, MRI scanner manufacturer, and total brain volume, where applicable.

Results

The overlap between male and female distributions was universally greater than the difference (overlap coefficient range: 0.585 - 0.985) and the ratio of within-sex and between-sex differences was similar (ANOSIM R range: -0.001 - 0.117). All cortical and subcortical volumes showed significant inhomogeneity of variance, whereas a minority of brain regions showed significant sex differences in variance for cortical thickness, white matter volume, fractional anisotropy, and mean diffusivity. Inhomogeneity of variance was reduced after accounting for other sources of variance. Overlap coefficients were larger and ANOSIM R values were smaller for residualized outcomes, indicating greater within- and smaller between-sex differences once accounting for other covariates.

Conclusions

Reported sex differences in early adolescent human brain structure may be driven by disparities in variance, rather than binary, sex-based phenotypes. Contrary to the popular view of the brain as sexually dimorphic, we found more similarity than difference between sexes in all global and regional measurements of brain structure examined. This study builds upon previous findings illustrating the importance of considering variance when examining sex differences in brain structure.

Intensity of Physical Activity in Young People: Focus on Emotional, Cognitive, and Healthy Lifestyle-Related Variables

The college years represent a crucial developmental period in which unhealthy behaviors, including smoking, alcohol consumption, inadequate physical activity (PA), poor sleep quality, and unhealthy nutrition habits are often acquired, influencing the onset or exacerbation of pre-existing mental disturbances such as anxiety, depression, or difficulties in emotion regulation. Our aim was to analyze the effect of the intensity of physical activity (PA) on the emotional, behavioral, and cognitive variables in a sample of young people. We recruited 103 participants (19.85 ± 0.25) who completed several online questionnaires (IPAQ-SF, STAI-t, DERS, UPPS-P, ISP-20, and Mini-IPIP). Subsequently, face-to-face sessions were conducted to assess the cognitive variables and to collect more details about their lifestyle habits, including drug use, sleep quality, and leisure activities. Based on the IPAQ-SF results, we categorized the sample into three groups: light PA (n = 47), moderate PA (n = 29), and vigorous PA (n = 27). Vigorous PA group showed better emotional regulation, lower impulsivity, fewer prefrontal symptoms and unhealthy behaviors, better sleep quality, and more leisure activities. No significant cognitive differences were found. It seems that young people are a vulnerable group with emotional and impulsivity traits and engaging in intense PA appears to be a promising avenue for managing these symptoms. In conclusion, our study suggests that young people are a vulnerable group with emotional and impulsivity traits that may precipitate in future mental disorders. Nevertheless, engaging in PA, particularly at high intensity, appears to be a promising avenue for reducing and managing these symptoms during this critical period of life.

More similarity than difference: comparison of within- and between-sex variance in early adolescent brain structure

Background

Adolescent neuroimaging studies of sex differences in the human brain predominantly examine mean differences between males and females. This focus on between-groups differences without probing relative distributions and similarities may contribute to both conflation and overestimation of sex differences and sexual dimorphism in the developing human brain.

Methods

We aimed to characterize the variance in brain macro- and micro-structure in early adolescence as it pertains to sex at birth using a large sample of 9-11 year-olds from the Adolescent Brain Cognitive Development (ABCD) Study (N=7,723). Specifically, for global and regional estimates of gray and white matter volume, cortical thickness, and white matter microstructure (i.e., fractional anisotropy and mean diffusivity), we examined: within- and between-sex variance, overlap between male and female distributions, inhomogeneity of variance via the Fligner-Killeen test, and an analysis of similarities (ANOSIM). For completeness, we examined these sex differences using both uncorrected (raw) brain estimates and residualized brain estimates after using mixed-effects modeling to account for age, pubertal development, socioeconomic status, race, ethnicity, MRI scanner manufacturer, and total brain volume, where applicable.

Results

The overlap between male and female distributions was universally greater than the difference (overlap coefficient range: 0.585 - 0.985) and the ratio of within-sex and between-sex differences was similar (ANOSIM R range: -0.001 - 0.117). All cortical and subcortical volumes showed significant inhomogeneity of variance, whereas a minority of brain regions showed significant sex differences in variance for cortical thickness, white matter volume, fractional anisotropy, and mean diffusivity. Inhomogeneity of variance was reduced after accounting for other sources of variance. Overlap coefficients were larger and ANOSIM R values were smaller for residualized outcomes, indicating greater within- and smaller between-sex differences once accounting for other covariates.

Conclusions

Reported sex differences in early adolescent human brain structure may be driven by disparities in variance, rather than binary, sex-based phenotypes. Contrary to the popular view of the brain as sexually dimorphic, we found more similarity than difference between sexes in all global and regional measurements of brain structure examined. This study builds upon previous findings illustrating the importance of considering variance when examining sex differences in brain structure.

Physical Fitness and Risk of Mental Disorders in Children and Adolescents

Importance

With the rising prevalence of mental disorders among children and adolescents, identifying modifiable associations is critical.

Objective

To examine the association between physical fitness and mental disorder risks.

Design, Setting, and Participants

This nationwide cohort study used data from the Taiwan National Student Fitness Tests and National Health Insurance Research Databases from January 1, 2009 to December 31, 2019. Participants were divided into 2 cohorts targeting anxiety and depression (1 996 633 participants) and attention-deficit/hyperactivity disorder (ADHD; 1 920 596 participants). Participants were aged 10 to 11 years at study entry and followed up for at least 3 years, had a nearly equal gender distribution, and an average follow-up of 6 years. Data were analyzed from October 2022 to February 2024.

Exposures

Assessments of physical fitness included cardiorespiratory fitness (CF), muscular endurance (ME), muscular power (MP), and flexibility, measured through an 800-m run time, bent-leg curl-ups, standing broad jump, and sit-and-reach test, respectively.

Main Outcomes and Measures

Kaplan-Meier method calculated the cumulative incidence of anxiety, depression, and ADHD across fitness quartiles. Additionally, multivariable Cox proportional hazards models were used that included all 4 fitness components and explored sex and income as modifiers.

Results

The anxiety and depression cohort had 1 996 633 participants (1 035 411 participants were male [51.9%], and the median [IQR] age was 10.6 [10.3-11.0] years), while the ADHD cohort had 1 920 596 (975 568 participants were male [51.9%], and the median [IQR] age was 10.6 [10.3-11.0] years). Cumulative incidence of mental disorders was lower among participants in better-performing fitness quartiles, suggesting a dose-dependent association. Gender-specific analyses, controlling for confounders, revealed that improved CF, indicated by a 30-second decrease in run times, was associated with reduced risks of anxiety, depression, and ADHD in female participants, and lower risks of anxiety and ADHD in male participants (adjusted hazard ratio [aHR] for ADHD risk for female participants, 0.92; 95% CI, 0.90-0.94; P < .001; for male participants, 0.93; 95% CI, 0.92-0.94; P < .001). Enhanced ME, marked by an increase of 5 curl-ups per minute, was associated with decreased risks of depression and ADHD in female participants, and lower anxiety and ADHD risks in male participants (aHR for ADHD risk for female participants, 0.94; 95% CI, 0.92-0.97; P < .001; for male participants, 0.96; 95% CI, 0.95-0.97; P < .001). Improved MP, reflected by a 20-cm increase in jump distance, was associated with reduced risks of anxiety and ADHD in female participants and reduced anxiety, depression, and ADHD in male participants (aHR for ADHD risk for female participants, 0.95; 95% CI, 0.91-1.00; P = .04; for male participants, 0.96; 95% CI, 0.94-0.99; P = .001).

Conclusions and Relevance

This study highlights the potential protective role of cardiorespiratory fitness, muscular endurance, and muscular power in preventing the onset of mental disorders. It warrants further investigation of the effectiveness of physical fitness programs as a preventive measure for mental disorders among children and adolescents.

Maintaining a Dynamic Brain: A Review of Empirical Findings Describing the Roles of Exercise, Learning, and Environmental Enrichment in Neuroplasticity from 2017-2023

Brain plasticity, also termed neuroplasticity, refers to the brain's life-long ability to reorganize itself in response to various changes in the environment, experiences, and learning. The brain is a dynamic organ capable of responding to stimulating or depriving environments, activities, and circumstances from changes in gene expression, release of neurotransmitters and neurotrophic factors, to cellular reorganization and reprogrammed functional connectivity. The rate of neuroplastic alteration varies across the lifespan, creating further challenges for understanding and manipulating these processes to benefit motor control, learning, memory, and neural remodeling after injury. Neuroplasticity-related research spans several decades, and hundreds of reviews have been written and published since its inception. Here we present an overview of the empirical papers published between 2017 and 2023 that address the unique effects of exercise, plasticity-stimulating activities, and the depriving effect of social isolation on brain plasticity and behavior.

Physical training improves inhibitory control in children aged 7-12 years: An fNIRS study

Physical exercise plays a crucial role in the development of cognition and brain functions in children. Inhibitory control is an advanced cognition that affects children's life and learning. In the current study, the relationship between physical training and inhibitory control was explored. In total, 80 children were randomly but equally assigned to the experimental and control groups. The experimental group underwent physical training (volleyball) for 60 min, thrice a week for 12 weeks. In contrast, the control group did not undergo any training and continued with their daily routines. The flanker task and functional near-infrared spectroscopy (fNIRS) were employed to investigate the effects of 12-week physical training on inhibitory control and changes in the oxy-Hb concentration in the prefrontal cortex (PFC) during the task. The behavioral results revealed that the experimental group performed better on the flanker task (e.g., shorter response time [F(1,74) = 18.420, p < 0.001, ηp2 = 0.199] and higher accuracy [F(1,74) = 15.00, p < 0.001, ηp2 = 0.169] than the control group. The oxy-Hb concentration in the right dorsolateral PFC (R-DLPFC) was higher and the activation level of this region was higher during the flanker task [F(1,74) = 6.216, p < 0.05, ηp2 = 0.077]. Moreover, the McNemar test revealed improved cognitive performance in response time or accuracy and R-DLPFC activation induced by physical exercise coincided significantly (χ2 = 5.49, p < 0.05; χ2 = 6.081, p < 0.05). These findings suggest that the R-DLPFC is likely the neural substrate for improved cognitive performance elicited by 12-week physical training.

Multimodal neuroimaging correlates of physical-cognitive covariation in Chilean adolescents. The Cogni-Action Project

Health-related behaviours have been related to brain structural features. In developing settings, such as Latin America, high social inequality has been inversely associated with several health-related behaviours affecting brain development. Understanding the relationship between health behaviours and brain structure in such settings is particularly important during adolescence when critical habits are acquired and ingrained. In this cross-sectional study, we carry out a multimodal analysis identifying a brain region associated with health-related behaviours (i.e., adiposity, fitness, sleep problems and others) and cognitive/academic performance, independent of socioeconomic status in a large sample of Chilean adolescents. Our findings suggest that the relationship between health behaviours and cognitive/academic performance involves a particular brain phenotype that could play a mediator role. These findings fill a significant gap in the literature, which has largely focused on developed countries and raise the possibility of promoting healthy behaviours in adolescence as a means to influence brain structure and thereby cognitive/academic achievement, independently of socioeconomic factors. By highlighting the potential impact on brain structure and cognitive/academic achievement, policymakers could design interventions that are more effective in reducing health disparities in developing countries.

Aerobic fitness as a moderator of acute aerobic exercise effects on executive function

This study aimed to investigate the moderating role of aerobic fitness on the effect of acute exercise on improving executive function from both behavioral and cerebral aspects. Thirty-four young individuals with motor skills were divided into high- and low-fitness groups based on their maximal oxygen uptake. Both groups completed 30 min of moderate-intensity aerobic exercise on a power bike. Executive function tests (Flanker, N-back, More-odd-shifting) were performed before and after exercise and functional near-infrared spectroscopy was used to monitor prefrontal cerebral blood flow changes during the tasks. The results indicated significant differences between the two groups regarding executive function. Participants with lower aerobic fitness performed better than their higher fitness counterparts in inhibitory control and working memory, but not in cognitive flexibility. This finding suggests that the aerobic fitness may moderate the extent of cognitive benefits gained from acute aerobic exercise. Furthermore, the neuroimaging data indicated negative activation in the frontopolar area and dorsolateral prefrontal cortex in response to three complex tasks. These findings underscore the importance of considering individual aerobic fitness when assessing the cognitive benefits of exercise and could have significant implications for tailoring fitness programs to enhance cognitive performance.

Neuroscience meets behavior: A systematic literature review on magnetic resonance imaging of the brain combined with real-world digital phenotyping

A primary goal of neuroscience is to understand the relationship between the brain and behavior. While magnetic resonance imaging (MRI) examines brain structure and function under controlled conditions, digital phenotyping via portable automatic devices (PAD) quantifies behavior in real-world settings. Combining these two technologies may bridge the gap between brain imaging, physiology, and real-time behavior, enhancing the generalizability of laboratory and clinical findings. However, the use of MRI and data from PADs outside the MRI scanner remains underexplored. Herein, we present a Preferred Reporting Items for Systematic Reviews and Meta-Analysis systematic literature review that identifies and analyzes the current state of research on the integration of brain MRI and PADs. PubMed and Scopus were automatically searched using keywords covering various MRI techniques and PADs. Abstracts were screened to only include articles that collected MRI brain data and PAD data outside the laboratory environment. Full-text screening was then conducted to ensure included articles combined quantitative data from MRI with data from PADs, yielding 94 selected papers for a total of N = 14,778 subjects. Results were reported as cross-frequency tables between brain imaging and behavior sampling methods and patterns were identified through network analysis. Furthermore, brain maps reported in the studies were synthesized according to the measurement modalities that were used. Results demonstrate the feasibility of integrating MRI and PADs across various study designs, patient and control populations, and age groups. The majority of published literature combines functional, T1-weighted, and diffusion weighted MRI with physical activity sensors, ecological momentary assessment via PADs, and sleep. The literature further highlights specific brain regions frequently correlated with distinct MRI-PAD combinations. These combinations enable in-depth studies on how physiology, brain function and behavior influence each other. Our review highlights the potential for constructing brain-behavior models that extend beyond the scanner and into real-world contexts.

How to design and establish a national school-based physical fitness monitoring and surveillance system for children and adolescents: A 10-step approach recommended by the FitBack network

BACKGROUND

Providing individual- and population-level data on children's physical fitness (PF) is a crucial public health and education priority. However, few national fitness monitoring or surveillance systems are currently in practice internationally. We aim to summarize the current European PF monitoring and surveillance systems for school-aged children and to provide experience-based guidelines on how to design such systems.

METHODS

The FitBack network consists of experts from diverse backgrounds with the common interest to improve the accessibility of PF monitoring for young people globally. Through FitBack network, we identified and compared the national or regional PF monitoring and surveillance systems currently in operation across Europe. We formulated a 10-step approach for designing and establishing one's own system, based on analysis of experienced strengths, weaknesses, opportunities, and threats to monitoring childhood fitness.

RESULTS

We identified a total of eight PF monitoring systems in Finland, France, Galicia of Spain, Hungary, Lithuania, Portugal, Serbia, and Slovenia. The FitBack network recommends the following steps for designing and establishing one's own system: (1) set up mission statements and aims, (2) involve stakeholders, (3) utilize scientific background, (4) governance structure, (5) ensure sufficient funding, (6) data management planning, (7) provide meaningful feedback, (8) conduct pilot testing, (9) plan implementation process, and (10) invest in communication with stakeholders.

CONCLUSIONS

This study provides an updated overview of the best practices for school-aged children's fitness monitoring and surveillance in Europe. Additionally, it offers a 10-step approach to assist in the creation of similar systems in Europe or globally.

Physical fitness is related to concentration performance in adolescents

The aim of this study was to test the relationship between physical fitness and attention in a sample of adolescents. The hypothesis was that the overall fitness as well as its single components (speed, endurance, strength, coordination, and flexibility) would be positively related to participants' performance in a test of attention. Participants were adolescent students (N = 140) aged 15 to 18 years. Physical fitness was measured with the German Motor Test. Attention was assessed with the d2-Test of Attention. Overall, physical fitness explained 26% of the variance in the attentional test performance. Endurance, strength, coordination, and flexibility were all positively linked to participants' attention, whereas speed was unrelated to attention. Endurance and flexibility better predicted how fast participants processed the test items, while strength and coordination better predicted the accuracy with which the participants detected the targets. Better physical fitness seems to be an advantage for adolescents' cognitive performance.

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.

Examining the relationship between aerobic fitness and cognitive control processes: An SFT and ERP study

Previous studies have demonstrated a positive relationship between aerobic fitness and cognitive control, the ability to inhibit distractions (conflict control) or impulsive actions (response inhibition). However, it is unknown whether these sub-processes and their underlying information processing capacity are differentially related to aerobic fitness. To address this question, we employed a go/no-go version of the redundant-target task, which was administered concurrently with the recording of event-related potentials (ERPs) and the use of a reaction-time based diagnostic tool known as system factorial technology (SFT). Our sample consisted of 46 young male adults with varying levels of aerobic fitness: the high-fit group (n = 23; aged 21.33 ± 2.44 years; VO2max 58.83 ± 6.93 ml/kg/min) and the low-fit group (n = 23; aged 22.30 ± 1.40 years; VO2max 41.90 ± 4.01 ml/kg/min). The results showed that the high-fit group exhibited a lower false-alarm rate compared to the low-fit group. However, there was no difference in processing speed between the two groups. The SFT analysis revealed that the high-fit group had more efficient information processing for earlier responses, but not later responses, compared to the low-fit group. Analysis of the ERPs indicated that the high-fit group had larger N2d amplitudes and shorter P3d latencies during conflict control compared to the low-fit group, while there were no such effects for the process of response inhibition. These findings suggest that aerobic fitness may be differentially related to the temporal dynamics and sub-processes of cognitive control.

Sex moderates the associations between physical activity intensity and attentional control in older adolescents

INTRODUCTION

The relationship between physical activity (PA) intensity and executive functions in older adolescents remains poorly understood. This study aimed to examine the associations between PA intensity, volume, attentional control, and working memory and the moderating effects of sex in older adolescents.

METHOD

We analyzed baseline data from 418 participants (211 females, Mage  = 16.5 ± 0.40 years) from the Burn 2 Learn trial. Adolescents wore GT9X Link accelerometers on a non-dominant wrist for 7 days, 24-h·d-1 . PA intensity was expressed as intensity gradient (IG) and moderate-to-vigorous PA (MVPA, Hildebrand cut-points); PA volume was expressed as average acceleration (AvACC). Attentional control was measured with a standard deviation (SDRT) and a coefficient of variation (CVRT) of the reaction time on the incongruent trials of a flanker task. Working memory was expressed as a d prime (a signal discrimination index) on the 2-back task. The moderating effects of sex on the PA-executive functions associations, adjusting for age, BMI z-score, and cardiorespiratory fitness, were tested using multilevel random intercept models.

RESULTS

After controlling for AvACC, sex moderated the relationships between IG and incongruent SDRT (B = 0.53, 95% CI: 0.12, 0.94) and CVRT (B = 0.63, 95% CI: 0.22, 1.05; ps ≤ 0.002). Only girls with higher IG showed smaller incongruent SDRT and CVRT (Bs ≤ -0.26, ps ≤ 0.01). IG was not related to working memory. AvACC and MVPA were not associated with attentional control or working memory.

CONCLUSION

Our findings reveal a novel association between higher-intensity PA and superior attentional control among adolescent girls.

Exploring the Mediating Role of Executive Function in the Relationship between Aerobic Fitness and Academic Achievement in Adolescents

(1) Background: The performance of physical activity at a sufficient volume can result in improvements in fitness. Aerobic fitness is a particular aspect of fitness that has consistently been shown to be related to both cognitive performance and academic achievement. Cognitive performance, particularly executive function, is itself predictive of academic achievement. It has been hypothesized that the benefits of aerobic fitness for academic achievement are due to improvements in executive function. This study explores the mediating role of cognitive performance on the relationship between physical fitness and academic achievement in high-school-aged adolescents. (2) Methods: High school students (N = 283, 127 male, 156 females, mean age = 16.05 years, SD = 0.41) performed a shuttle run test to assess aerobic fitness and completed the Stroop Color, Stroop Word, and Stroop Color–Word tests to measure information processing and inhibition. They also completed the National Union Academic Achievement Assessment (NUAAA) as part of their high school requirements. (3) Results: Mediation analyses showed that inhibition (performance in the Stroop Color–Word test) fully mediated the relationship between aerobic fitness and both mathematics and Korean performance. (4) Conclusions: This cross-sectional investigation suggests an important mediating role of cognitive performance related to executive function in understanding the relationship between aerobic fitness and the academic achievement of high-school-aged adolescents. This suggests that enhancements in performance related to executive function, which are attributed to increases in aerobic fitness, could explain the observed benefits for academic attainment.

The alterations of spontaneous neural activities and white matter microstructures in anti-N-methyl-D-aspartate receptor encephalitis: a resting-state fMRI and DTI study

BACKGROUND AND PURPOSE

Limited studies had jointly excavated the structural and functional changes in cognitive deficit in anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis patients. We aimed to explore these changes in anti-NMDAR patients and their effect on cognitive function.

METHODS

Twenty-three patients and 25 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging, diffusion tensor imaging scanning, and neuroethology tests. The significantly differentiated brain regions via the fractional amplitude of low-frequency fluctuation (fALFF) were defined as regions of interest (ROIs). Granger causal, functional connectivity, and tract-based spatial statistical analyses were applied to explore the functional changes in ROIs and assess the structural changes.

RESULTS

HCs outperformed patients in Montreal Cognitive Assessment. The fALFF values of right gyrus rectus (RGR) in patients were significantly reduced. The fractional anisotropy (FA) values of WM in the genu of corpus callosum and right superior corona radiata were significantly decreased and positively associated with neuroethology testing scores. The Granger causal connectivity (GCC) from the left inferior parietal lobule to RGR was significantly decreased and positively associated with inherent vigilance. Indicated by the multiple linear regression result, decreased FA value of the right superior corona radiata might be a reliable marker that reflects the cognitive impairment.

CONCLUSIONS

Significant changes in spontaneous neural activities, GCC, and WM structures in anti-NMDAR encephalitis were reported. These findings promote the understanding of underlying relationships between cerebral function, structural network alterations, and cognitive dysfunction.

Exercise in Adolescence Enhances Callosal White Matter Refinement in the Female Brain in a Rat Model of Fetal Alcohol Spectrum Disorders

A total of 1 in 20 infants born annually are exposed to alcohol prenatally, which disrupts neurodevelopment and results in several disorders categorized under the umbrella term Fetal Alcohol Spectrum Disorders (FASD). Children and adolescents affected by FASD exhibit delayed maturation of cerebral white matter, which contributes to deficits in executive function, visuospatial processing, sensory integration, and interhemispheric communication. Research using animal models of FASD have uncovered that oligoglia proliferation, differentiation, and survival are vulnerable to alcohol teratogenesis in the male brain due in part to the activation of the neuroimmune system during gestation and infancy. A comprehensive investigation of prenatal alcohol exposure on white matter development in the female brain is limited. This study demonstrated that the number of mature oligodendrocytes and the production of myelin basic protein were reduced first in the female corpus callosum following alcohol exposure in a rat model of FASD. Analysis of myelin-related genes confirmed that myelination occurs earlier in the female corpus callosum compared to their counterparts, irrespective of postnatal treatment. Moreover, dysregulated oligodendrocyte number and myelin basic protein production was observed in the male and female FASD brain in adolescence. Targeted interventions that support white matter development in FASD-affected youth are nonexistent. The capacity for an adolescent exercise intervention to upregulate corpus callosum myelination was evaluated: we discovered that volunteer exercise increases the number of mature oligodendrocytes in alcohol-exposed female rats. This study provides critical evidence that oligoglia differentiation is difficult but not impossible to induce in the female FASD brain in adolescence following a behavioral intervention.

Neurological soft signs in adolescents are associated with brain structure

Neurological soft signs (NSS) are minor deviations in motor performance. During childhood and adolescence, NSS are examined for functional motor phenotyping to describe development, to screen for comorbidities, and to identify developmental vulnerabilities. Here, we investigate underlying brain structure alterations in association with NSS in physically trained adolescents. Male adolescent athletes (n = 136, 13–16 years) underwent a standardized neurological examination including 28 tests grouped into 6 functional clusters. Non-optimal performance in at least 1 cluster was rated as NSS (NSS+ group). Participants underwent T1- and diffusion-weighted magnetic resonance imaging. Cortical volume, thickness, and local gyrification were calculated using Freesurfer. Measures of white matter microstructure (Free-water (FW), FW-corrected fractional anisotropy (FAt), axial and radial diffusivity (ADt, RDt)) were calculated using tract-based spatial statistics. General linear models with age and handedness as covariates were applied to assess differences between NSS+ and NSS− group. We found higher gyrification in a large cluster spanning the left superior frontal and parietal areas, and widespread lower FAt and higher RDt compared with the NSS− group. This study shows that NSS in adolescents are associated with brain structure alterations. Underlying mechanisms may include alterations in synaptic pruning and axon myelination, which are hallmark processes of brain maturation.

Effects of exercise types on white matter microstructure in late midlife adults: Preliminary results from a diffusion tensor imaging study

Higher aerobic fitness during late midlife is associated with higher white matter (WM) microstructure. Compared with individuals engaged in irregular exercise, those who engage in regular aerobic exercise show higher fractional anisotropy (FA), a diffusion tenor imaging (DTI) measure that provides an index of WM microstructural integrity. However, whether other types of exercise, such as Tai Chi, can also facilitate WM changes in adults during late midlife remains unknown. The present study compares two types of exercise, Tai Chi and walking, with a sedentary control group, in order to examine the effects of exercise on WM microstructure and determine the regional specificity of WM differences. Thirty-six healthy adults between the ages of 55 and 65 years participated in the study. Based on the participants' exercise habits, they were allocated into three groups: Tai Chi, walking, or sedentary control. All participants were required to complete physical fitness measurements and completed magnetic reasoning imaging (MRI) scans. Our results revealed that the Tai Chi group exhibited a higher FA value in the left cerebral peduncle, compared to the sedentary control group. We also observed that both the Tai Chi and walking groups exhibited higher FA values in the right uncinate fasciculus and the left external capsule, in comparison to the sedentary control group. Increased FA values in these regions was positively correlated with higher levels of physical fitness measurements (i.e., peak oxygen uptake [VO2peak], muscular endurance/number of push-up, agility, power). These findings collectively suggest that regular exercise is associated with improved WM microstructural integrity, regardless of the exercise type, which could guide the development and application of future prevention and intervention strategies designed to address age-related cognitive impairments during late midlife.

Risk factors for neurocognitive impairment and the relation with structural brain abnormality in children and young adults with severe chronic kidney disease

BACKGROUND

Severe chronic kidney disease (CKD) in children and young adults has shown to be associated with abnormal brain development, which may contribute to neurocognitive impairments. We aimed to investigate risk factors for neurocognitive impairment and investigate the relation with structural brain abnormalities in young severe CKD patients.

METHODS

This cross-sectional study includes 28 patients with severe CKD (eGFR < 30), aged 8-30 years (median 18.5 years), on different treatment modalities (pre-dialysis [n = 8], dialysis [n = 8], transplanted [n = 12]). We assessed neurocognitive functioning using a comprehensive test battery and brain structure by magnetic resonance imaging metrics of brain volume and white matter integrity (fractional anisotropy [FA] and mean diffusivity [MD] measured with diffusion tensor imaging). Multivariate regression and mediation analyses were performed between clinical CKD parameters, brain structure, and neurocognitive outcome.

RESULTS

A combination of risk factors (e.g., longer time since kidney transplantation, longer dialysis duration and late CKD onset) was significantly associated with lower intelligence and/or worse processing speed and working memory. Lower FA in a cluster of white matter tracts was associated with lower intelligence and mediated the relation between clinical risk factors and lower intelligence.

CONCLUSIONS

Young severe CKD patients with a prolonged duration of kidney replacement therapy, either dialysis or transplantation are at particular risk for impairments in intelligence, processing speed, and working memory. Disrupted white matter integrity may importantly contribute to these neurocognitive impairments. Prospective, longitudinal studies are needed to elucidate the mechanisms involved in CKD and treatment that affect white matter integrity and neurocognitive outcome in young patients. A higher resolution version of the Graphical abstract is available as Supplementary information.

Reduced and delayed myelination and volume of corpus callosum in an animal model of Fetal Alcohol Spectrum Disorders partially benefit from voluntary exercise

1 in 20 live births in the United States is affected by prenatal alcohol exposure annually, creating a major public health crisis. The teratogenic impact of alcohol on physical growth, neurodevelopment, and behavior is extensive, together resulting in clinical disorders which fall under the umbrella term of Fetal Alcohol Spectrum Disorders (FASD). FASD-related impairments to executive function and perceptual learning are prevalent among affected youth and are linked to disruptions to corpus callosum growth and myelination in adolescence. Targeted interventions that support neurodevelopment in FASD-affected youth are nonexistent. We evaluated the capacity of an adolescent exercise intervention, a stimulator of myelinogenesis, to upregulate corpus callosum myelination in a rat model of FASD (third trimester-equivalent alcohol exposure). This study employs in vivo diffusion tensor imaging (DTI) scanning to investigate the effects of: (1) neonatal alcohol exposure and (2) an adolescent exercise intervention on corpus callosum myelination in a rodent model of FASD. DTI scans were acquired twice longitudinally (pre- and post-intervention) in male and female rats using a 9.4 Tesla Bruker Biospec scanner to assess alterations to corpus callosum myelination noninvasively. Fractional anisotropy values as well as radial/axial diffusivity values were compared within-animal in a longitudinal study design. Analyses using mixed repeated measures ANOVA’s confirm that neonatal alcohol exposure in a rodent model of FASD delays the trajectory of corpus callosum growth and myelination across adolescence, with a heightened vulnerability in the male brain. Alterations to corpus callosum volume are correlated with reductions to forebrain volume which mediates an indirect relationship between body weight gain and corpus callosum growth. While we did not observe any significant effects of voluntary aerobic exercise on corpus callosum myelination immediately after completion of the 12-day intervention, we did observe a beneficial effect of exercise intervention on corpus callosum volume growth in all rats. In line with clinical findings, we have shown that prenatal alcohol exposure leads to hypomyelination of the corpus callosum in adolescence and that the severity of damage is sexually dimorphic. Further, exercise intervention improves corpus callosum growth in alcohol-exposed and control rats in adolescence.

Anthropometric Parameters, Physical Activity, Physical Fitness, and Executive Functions among Primary School Children

Physical activity during childhood and adolescence favors brain development and cognitive functioning, particularly the executive functions. This study aimed to assess potential associations between anthropometric parameters, physical activity, physical fitness, and executive functions among elementary school children returning to school after the COVID-19 lockdown in Chile. School-age male and female participants (n = 90; age, 10−12 years) participated in the study. To determine the association between variables, a multivariable linear regression analysis was performed. Higher fat-related anthropometric indexes were associated with lower working memory, cognitive flexibility, planning, and attention (r = −0.55 to −0.22; p = 0.031 to <0.001). In contrast, higher physical activity levels, better sprint performance, higher lower-body muscular power, and greater upper-body muscular strength were associated with better working memory, cognitive flexibility, inhibition, planning, and/or attention (r = 0.19 to −0.54; p = 0.04 to <0.001). Current results consistently suggest the need for adequate levels of physical activity, physical fitness, and anthropometric parameters among the school-age population to promote healthy and adequate executive functions.

Age-Related Trajectories of Brain Structure–Function Coupling in Female Roller Derby Athletes

Contact and collision sports are believed to accelerate brain aging. Postmortem studies of the human brain have implicated tau deposition in and around the perivascular space as a biomarker of an as yet poorly understood neurodegenerative process. Relatively little is known about the effects that collision sport participation has on the age-related trajectories of macroscale brain structure and function, particularly in female athletes. Diffusion MRI and resting-state functional MRI were obtained from female collision sport athletes (n = 19 roller derby (RD) players; 23–45 years old) and female control participants (n = 14; 20–49 years old) to quantify structural coupling (S_C) and decoupling (S_D). The novel and interesting finding is that RD athletes, but not controls, exhibited increasing S_C with age in two association networks: the frontoparietal network, important for cognitive control, and default-mode network, a task-negative network (permuted p = 0.0006). Age-related increases in S_C were also observed in sensorimotor networks (RD, controls) and age-related increases in S_D were observed in association networks (controls) (permuted p ≤ 0.0001). These distinct patterns suggest that competing in RD results in compressed neuronal timescales in critical networks as a function of age and encourages the broader study of female athlete brains across the lifespan.

Physical Activity, Fitness, and Executive Functions in Youth: Effects, Moderators, and Mechanisms

Over the last decade, a growing body of research has examined the link between physical activity, fitness, and cognitive function in children and adolescents. Physical activity experimental research conducted with children and adolescents has identified selectively greater effects for tasks requiring higher order executive functions. As such, the primary aim of our chapter is to provide an overview of findings from systematic reviews and meta-analyses that have examined the effects of physical activity on measures of executive function in child and adolescent populations. We begin our chapter with definitions of key concepts associated with physical activity, fitness and cognitive function. We then provide a synthesis of systematic reviews and meta-analyses that have examined the acute and chronic effect of physical activity on EFs. Following this, we discuss the quantitative (e.g., time, intensity) and qualitative (e.g., type) characteristics of physical activity that may moderate effects. The next section focuses on the neurobiological, psychosocial and behavioral mechanisms responsible for the effect of physical activity on executive functions. We conclude by highlighting the limitations of the existing evidence base and providing recommendations for future research.

Regional White Matter Diffusion Changes Associated with the Cumulative Tensile Strain and Strain Rate in Nonconcussed Youth Football Players

The purpose of this study is to assess the relationship between regional white matter diffusion imaging changes and finite element strain measures in nonconcussed youth football players. Pre- and post-season diffusion-weighted imaging was performed in 102 youth football subject-seasons, in which no concussions were diagnosed. The diffusion data were normalized to the IXI template. Percent change in fractional anisotropy (%ΔFA) images were generated. Using data from the head impact telemetry system, the cumulative maximum principal strain one times strain rate (CMPS1 × SR), a measure of the cumulative tensile brain strain and strain rate for one season, was calculated for each subject. Two linear regression analyses were performed to identify significant positive or inverse relationships between CMPS1 × SR and %ΔFA within the international consortium for brain mapping white matter mask. Age, body mass index, days between pre- and post-season imaging, previous brain injury, attention disorder diagnosis, and imaging protocol were included as covariates. False discovery rate correction was used with corrected alphas of 0.025 and voxel thresholds of zero. Controlling for all covariates, a significant, positive linear relationship between %ΔFA and CMPS1 × SR was identified in the bilateral cingulum, fornix, internal capsule, external capsule, corpus callosum, corona radiata, corticospinal tract, cerebral and middle cerebellar peduncle, superior longitudinal fasciculus, and right superior fronto-occipital fasciculus. Post hoc analyses further demonstrated significant %ΔFA differences between high-strain football subjects and noncollision control athletes, no significant %ΔFA differences between low-strain subjects and noncollision control athletes, and that CMPS1 × SR significantly explained more %ΔFA variance than number of head impacts alone.

Could Physical Fitness Be Considered as a Protective Social Factor Associated with Bridging the Cognitive Gap Related to School Vulnerability in Adolescents? The Cogni-Action Project

The first aim was to compare differences between school vulnerability groups, fitness levels, and their combination in adolescent cognitive performance. The second aim was to determine the mediation role of fitness in the association between school vulnerability and cognitive performance. A total of 912 Chilean adolescents aged 10–14 years participated in this study. The school vulnerability index (SVI) assigned by the Chilean Government was categorized into high-, mid-, or low-SVI. Adolescents were classified as fit or unfit according to their global fitness z-score computed from their cardiorespiratory (CRF), muscular (MF), and speed/agility fitness (SAF) adjusted for age and sex. A global cognitive score was estimated through eight tasks based on a neurocognitive battery. Covariance and mediation analyses were performed, adjusted for sex, schools, body mass index, and peak high velocity. Independent analyses showed that the higher SVI, the lower the cognitive performance (F_(6,905) = 18.5; p < 0.001). Conversely, fit adolescents presented a higher cognitive performance than their unfit peers (F_(5,906) = 8.93; p < 0.001). The combined analysis found cognitive differences between fit and unfit adolescents in both the high- and mid-SVI levels (Cohen’s d = 0.32). No differences were found between fit participants belonging to higher SVI groups and unfit participants belonging to lower SVI groups. Mediation percentages of 9.0%, 5.6%, 7.1%, and 2.8% were observed for the global fitness score, CRF, MF, and SAF, respectively. The mediation effect was significant between low- with mid-high-SVI levels but not between mid- and high-SVI levels. These findings suggest that an adequate physical fitness level should be deemed a protective social factor associated with bridging the cognitive gap linked to school vulnerability in adolescents. This favourable influence seems to be most significant in adolescents belonging to a more adverse social background.

Gym-Goers Preference Analysis of Fitness Centers during the COVID-19 Pandemic: A Conjoint Analysis Approach for Business Sustainability

The COVID-19 pandemic has had a great impact on the fitness centers industry. The purpose of this study is to analyze the preference of gym-goers on fitness centers in the Philippines during the COVID-19 pandemic by utilizing a conjoint analysis approach. One thousand gym-goers voluntarily participated in this study and answered 22 queries created from the orthogonal design. The results indicated that Price was the highest attribute considered (21.59%), followed by Ventilation (17.56%), Service (16.59%), Trainer (14.63%), Payment Method (11.95%), Operating Hours (8.90%), and Login (8.70%). The results also indicated that comfort, security, and fitness center services were the main aspects that gym-goers would consider as their main preference. The study highlighted how gym-goers are sensitive to the price set by the fitness centers. Moreover, due to the COVID-19 pandemic, ventilation and size are considered highly important attributes among gym-goers. Comfort, safety, and security are the main consideration to have sustainable fitness centers during and even after the COVID-19 pandemic. The outcome of this study may benefit fitness centers and increase their business market by considering the preference of customers. Finally, the result of this study can be utilized by fitness centers to promote a generalized fitness center for gym-goers of different generations, statuses, and even socioeconomic status during and even after the COVID-19 pandemic.

The relationship between white matter microstructure, cardiovascular fitness, gross motor skills, and neurocognitive functioning in children

Recent evidence indicates that both cardiovascular fitness and gross motor skill performance are related to enhanced neurocognitive functioning in children by influencing brain structure and functioning. This study investigates the role of white matter microstructure in the relationship of both cardiovascular fitness and gross motor skills with neurocognitive functioning in healthy children. In total 92 children (mean age 9.1 years, range 8.0-10.7) were included in this study. Cardiovascular fitness and gross motor skill performance were assessed using performance-based tests. Neurocognitive functioning was assessed using computerized tests (working memory, inhibition, interference control, information processing, and attention). Diffusion tensor imaging was used in combination with tract-based spatial statistics to assess white matter microstructure as defined by fractional anisotropy (FA), axial and radial diffusivity (AD, RD). The results revealed positive associations of both cardiovascular fitness and gross motor skills with neurocognitive functioning. Information processing and motor response inhibition were associated with FA in a cluster located in the corpus callosum. Within this cluster, higher cardiovascular fitness and better gross motor skills were both associated with greater FA, greater AD, and lower RD. No mediating role was found for FA in the relationship of both cardiovascular fitness and gross motor skills with neurocognitive functioning. The results indicate that cardiovascular fitness and gross motor skills are related to neurocognitive functioning as well as white matter microstructure in children. However, this study provides no evidence for a mediating role of white matter microstructure in these relationships.

Influence of Aerobic Fitness on White Matter Integrity and Inhibitory Control in Early Adulthood: A 9-Week Exercise Intervention

Previous cross-sectional studies have related aerobic fitness to inhibitory control and white matter (WM) microstructure in young adults, but there is no longitudinal study to confirm whether these relationships exist. We carried out a longitudinal study comparing aerobic fitness, inhibitory control, and WM integrity across time points, before versus after completing an exercise intervention in young adults (18–20 years old) relative to a control group. The exercise group (n = 35) participated in a 9-week exercise protocol, while the control group (n = 24) did not receive any regular exercise training. Behavioral data and diffusion tensor imaging (DTI) data were collected prior to and following the intervention. After the exercise intervention, aerobic fitness and inhibitory control performance were significantly improved for the exercise group, but not for the control group. Analyses of variance (ANOVA) of the DTI data demonstrated significantly increased fractional anisotropy (FA) in the right corticospinal tract and significantly decreased FA in the left superior fronto-occipital fasciculus in the exercise group after the intervention versus before. The enhanced aerobic fitness induced by exercise was associated with better inhibitory control performance in the incongruent condition and lower FA in the Left superior fronto-occipital fasciculus (SFOF). Regression analysis of a mediation model did not support Left SFOF FA as a mediator of the relationship between improvements in aerobic fitness and inhibitory control. The present data provide new evidence of the relationship between exercise-induced changes in aerobic fitness, WM integrity, and inhibitory control in early adulthood. Longer-duration intervention studies with larger study cohorts are needed to confirm and further explore the findings obtained in this study.

Child physical activity as a modifier of the relationship between prenatal exposure to maternal overweight/obesity and neurocognitive outcomes in offspring

BACKGROUND/OBJECTIVES

With rising obesity rates among pregnant women, more children are exposed in utero to maternal obesity. In prior epidemiological studies, exposure to maternal obesity was associated with lower intelligence quotient (IQ) scores and worse cognitive abilities in offspring. Further studies have shown that offspring exposed to maternal obesity, exhibit differences in the white matter microstructure properties, fractional anisotropy (FA) and mean diffusivity (MD). In contrast, physical activity was shown to improve cognition and white matter microstructure during childhood. We examined if child physical activity levels modify the relationship between prenatal exposure to maternal obesity with IQ and white matter microstructure in offspring.

SUBJECTS/METHODS

One hundred children (59% girls) age 7-11 years underwent brain magnetic resonance imaging and IQ testing. Maternal pre-pregnancy BMI was abstracted from electronic medical records. White matter was assessed using diffusion tensor imaging with the measures, global FA, MD. The 3-day physical activity recall was used to measure moderate-to-vigorous physical activity and vigorous physical activity (VPA). Linear regression was used to test for interactions between prenatal exposure to maternal overweight/obesity and child PA levels on child IQ and global FA/MD.

RESULTS

The relationship between prenatal exposure to maternal overweight/obesity and child IQ and global FA varied by child VPA levels. Children exposed to mothers with overweight/obesity who engaged in more VPA had higher IQ scores and global FA compared to exposed children who engaged in less VPA. Associations were independent of child age, sex, BMI Z-score and socioeconomic status. Children born to normal-weight mothers did not differ in either IQ or global FA by time in VPA.

CONCLUSIONS

Our findings support findings in rodent models and suggest that VPA during childhood modifies the relationship between prenatal exposure to maternal obesity and child IQ and white matter microstructure.

Childhood exercise predicts response inhibition in later life via changes in brain connectivity and structure

Participation in exercise during early life (i.e., childhood through adolescence) enhances response inhibition; however, it is unclear whether participation in exercise during early life positively predicts response inhibition in later life. This historical cohort study was designed to clarify whether participation in exercise (e.g., structured sports participation) during early life predicts response inhibition in adulthood and if so, to reveal the brain connectivity and cortical structures contributing to this association. We analyzed data derived from 214 participants (women = 104, men = 110; age: 26‒69 years). Results indicated that participation in exercise during childhood (before entering junior high school; ≤ 12 years old) significantly predicted better response inhibition. No such association was found if exercise participation took place in early adolescence or later (junior high school or high school; ≥ 12 years old). The positive association of exercise participation during childhood with response inhibition was moderated by decreased structural and functional connectivity in the frontoparietal (FPN), cingulo-opercular (CON), and default mode networks (DMN), and increased inter-hemispheric structural networks. Greater cortical thickness and lower levels of dendritic arborization and density in the FPN, CON, and DMN also moderated this positive association. Our results suggest that participation in exercise during childhood positively predicts response inhibition later in life and that this association can be moderated by changes in neuronal circuitry, such as increased cortical thickness and efficiency, and strengthened inter-hemispheric connectivity.

Executive Functions and Domain-Specific Cognitive Skills in Climbers

Athletes in a particular sport have specific cognitive skills acquired due to regular confrontation with sport-specific requirements. Studies show that the particular type of sport carried out and fostered by general physical activity impacts executive functions (EFs) such as inhibition, working memory, and cognitive flexibility. There are inconsistent results on the connections between domain-specific cognitive skills and executive functions. This study aimed to evaluate the relations between EFs and domain-specific cognitive skills in climbing. Due to that, we examined the executive functions (neuropsychological tests) and domain-specific cognitive skills (climbing-specific test: a preview of the route vs. climbed moves; climbed moves vs. recognition of moves) of 19 climbers (10 novices, 9 experts, grades 5 to 6a vs. 6c+ to 7b). The inter-subject effects analysis shows that novices and experts in sport climbing do not differ in executive functions in this particular case. Concerning domain-specific cognitive skills, there are differences between experts and novices. Experts show a significantly higher level in planning performance or route idea (p < 0.001) as well as in memorizing of climbed moves (p = 0.004). There are no relations between executive functions and domain-specific cognitive skills in climbers.

Development of Perceptual Inhibition in Adolescents—A Critical Period?

Recent studies suggest that the developmental curves in adolescence, related to the development of executive functions, could be fitted to a non-linear trajectory of development with progressions and retrogressions. Therefore, the present study proposes to analyze the pattern of development in Perceptual Inhibition (PI), considering all stages of adolescence (early, middle, and late) in intervals of one year. To this aim, we worked with a sample of 275 participants between 10 and 25 years, who performed a joint visual and search task (to measure PI). We have fitted ex-Gaussian functions to the probability distributions of the mean response time across the sample and performed a covariance analysis (ANCOVA). The results showed that the 10- to 13-year-old groups performed similarly in the task and differ from the 14- to 19-year-old participants. We found significant differences between the older group and all the rest of the groups. We discuss the important changes that can be observed in relation to the nonlinear trajectory of development that would show the PI during adolescence.

Physical activity and aerobic fitness show different associations with brain processes underlying anticipatory selective visuospatial attention in adolescents

Current knowledge about the underlying brain processes of exercise-related benefits on executive functions and the specific contributions of physical activity and aerobic fitness during adolescence is inconclusive. We explored whether and how physical activity and aerobic fitness are associated with the oscillatory dynamics underlying anticipatory spatial attention. We studied whether the link between physical exercise level and cognitive control in adolescents is mediated by task-related oscillatory activity. Magnetoencephalographic alpha oscillations during a modified Posner's cueing paradigm were measured in 59 adolescents (37 females and 22 males, 12-17 years). Accelerometer-measured physical activity and aerobic fitness (20-m shuttle run test) were used to divide the sample into higher- and lower-performing groups. The interhemispheric alpha asymmetry during selective attention was larger in the high than in the low physical activity group, but there was no difference between the high and low aerobic fitness groups. Exploratory mediation analysis suggested that anticipatory interhemispheric asymmetry mediates the association between physical activity status and drift rate in the selective attention task. Higher physical activity was related to increased cue-induced asymmetry, which in turn was associated with less efficient processing of information. Behaviorally, more physically active males showed stronger dependence on the cue, while more fit females showed more efficient processing of information. Our findings suggest that physical activity may be associated with a neural marker of anticipatory attention in adolescents. These findings might help to explain the varying results regarding the association of physical activity and aerobic fitness with attention and inhibition in adolescents.

Collegiate athlete brain data for white matter mapping and network neuroscience

We describe a dataset of processed data with associated reproducible preprocessing pipeline collected from two collegiate athlete groups and one non-athlete group. The dataset shares minimally processed diffusion-weighted magnetic resonance imaging (dMRI) data, three models of the diffusion signal in the voxel, full-brain tractograms, segmentation of the major white matter tracts as well as structural connectivity matrices. There is currently a paucity of similar datasets openly shared. Furthermore, major challenges are associated with collecting this type of data. The data and derivatives shared here can be used as a reference to study the effects of long-term exposure to collegiate athletics, such as the effects of repetitive head impacts. We use advanced anatomical and dMRI data processing methods publicly available as reproducible web services at brainlife.io.

Physical activity and aerobic fitness in relation to local and interhemispheric functional connectivity in adolescents' brains

INTRODUCTION

Adolescents have experienced decreased aerobic fitness levels and insufficient physical activity levels over the past decades. While both physical activity and aerobic fitness are related to physical and mental health, little is known concerning how they manifest in the brain during this stage of development, characterized by significant physical and psychosocial changes. The aim of the study is to examine the associations between both physical activity and aerobic fitness with brains' functional connectivity.

METHODS

Here, we examined how physical activity and aerobic fitness are associated with local and interhemispheric functional connectivity of the adolescent brain (n = 59), as measured with resting-state functional magnetic resonance imaging. Physical activity was measured by hip-worn accelerometers, and aerobic fitness by a maximal 20-m shuttle run test.

RESULTS

We found that higher levels of moderate-to-vigorous intensity physical activity, but not aerobic fitness, were linked to increased local functional connectivity as measured by regional homogeneity in 13-16-year-old participants. However, we did not find evidence for significant associations between adolescents' physical activity or aerobic fitness and interhemispheric connectivity, as indicated by homotopic connectivity.

CONCLUSIONS

These results suggest that physical activity, but not aerobic fitness, is related to local functional connectivity in adolescents. Moreover, physical activity shows an association with a specific brain area involved in motor functions but did not display any widespread associations with other brain regions. These results can advance our understanding of the behavior-brain associations in adolescents.

Global Cognitive Functioning versus Controlled Functioning throughout the Stages of Development

According to the All or None Hypothesis (Diamond, 2009), the cognitive system can operate in a global manner that is not very discriminate or in a more discriminate mode that demands greater precision, control, and cognitive effort. There are five corollaries to this hypothesis that describe, in an operative way, the conditions under which the controlled mode of functioning in the cognitive domain can be activated and thus tested. Given the impact this theory has generated and the absence of studies analyzing the corollaries in a collective and systematic way at different stages of development, this study was proposed, first of all, to test three of these corollaries in children, adolescents and adults and, secondly, to analyze the changes in the controlled mode of functioning during these three stages of development. To this end, the Fingers Task, a modified version of Arrows Task (with two rules: response ipsilateral where the stimulus is presented, symmetry; and response contralateral, asymmetry), was administered to a sample of 123 participants (43 children, 44 adolescents, and 36 adults). In general, the results verify the corollaries and identify the changes that the controlled mode of functioning experiences at different stages of development.

The Roles of Physical Activity, Exercise, and Fitness in Promoting Resilience During Adolescence: Effects on Mental Well-Being and Brain Development

Adolescence is a critical yet vulnerable period for developing behaviors important for mental well-being. The existing literature suggests that physical activity (PA), exercise, and aerobic fitness promote well-being and reduce risk of mental health problems. In this review, we focus on PA, exercise, and fitness as modifiable resilience factors that may help promote self-regulation via strengthening of top-down control of bottom-up processes in the brain, thereby acting as a buffer against mental health problems during this period of vulnerability. First, we briefly review the link between PA, exercise, and aerobic fitness with mental well-being and reduced mental health problems in adolescence. Then we present how impairments in self-regulation, which involves top-down control to modulate bottom-up processes, are common across a wide range of mental health disorders. Finally, we use the extant neuroimaging literature to highlight how neural systems underlying top-down control continue to develop across adolescence, and propose that PA, exercise, and aerobic fitness may facilitate resilience through strengthening individual brain regions as well as large-scale neural circuits to improve emotional and behavioral regulation. Future neuroimaging studies assessing the effects of PA, exercise, and aerobic fitness at various developmental stages in each sex and studies considering the characteristics (e.g., frequency, intensity, type) and social context of PA and exercise are vital to better understand both macro- and microscale mechanisms by which these behaviors and attributes may facilitate mental health resilience during adolescent development.