Sympathetic Nervous System Mediation of Acute Exercise Effects on Childhood Brain and Cognition

Study Overview
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Brief Summary
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Today's children have become increasingly inactive and unfit, with >50% of children not meeting the recommended 60 min of moderate-to-vigorous physical activity. Previous research has suggested that acute aerobic exercise of moderate intensity was associated with improved cognition manifested by improved performance and increased P3 amplitude, a neuroelectric indicator that reflects the amount of attentional allocation, in tasks requiring cognitive control. While minimal evidence exists to support potential mechanisms underlying the transient effects of exercise on brain and cognition, research suggests that phasic changes in the locus coeruleus-norepinephrine (LC-NE) (as measured by salivary alpha amylase (sAA)) system are a potential mechanism for explaining the acute effect of exercise on brain and cognition. Accordingly, the aim of this study is to examine the mechanisms linking acute aerobic exercise to improved cognitive control as well as the underlying neuroelectrical activities in children, using electroencephalography (EEG) and event-related potentials (ERPs). We hope to gain a better understanding of the role of acute exercise and cognitive and brain health. The results from this study will help identify mechanisms linking acute exercise to enhanced cognitive performance in children. Our hypothesis is that exercise-induced phasic increases in sympathetic nervous system activity will mediate the effect of a single bout of exercise on brain function, cognition, and standardized achievement test performance.

Official Title
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Sympathetic Nervous System Mediation of Acute Exercise Effects on Childhood Brain and Cognition

Conditions
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Exercise, Cognition

Intervention / Treatment
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* Other: Aerobic Exercise Intervention
* Other: Trier Social Stress Test for Children
* Other: Seated Rest


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Parental/guardian consent (non-consent of guardian). Participants must have had no prior diagnosis of cognitive or physical disability, including attention deficit hyperactivity disorder (severe asthma, epilepsy, chronic kidney disease, and dependence upon a wheelchair/walking aid). Participants must be free of any type of anti-psychotic, anti-depressant, anti-anxiety medication, as well as those medications used for attention deficit hyperactivity disorder (use of any anti-psychotic, anti-depressant, anti-anxiety, and attention deficit hyperactivity disorder medications). Normal or corrected-to-normal vision based on the minimal 20/20 standard in order to complete the cognitive task (below 20/20 vision). Participants must have not yet reached, or be in the earliest stages, of puberty, as measured by a modified test of the Tanner Staging System (onset of puberty as determined by Tanner). English speaking. Exclusion Criteria: Participants with an intelligence quotient below 85 will be excluded.

Ages Eligible for Study
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Minimum Age: 9 Years
Maximum Age: 10 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Aerobic Exercise Intervention<br>Participants will exercise on a motor-driven treadmill at a constant speed during the 23-min period. | Other: Aerobic Exercise Intervention<br>* The protocol will include a 25-min bout of exercise at an intensity of 75% HRmax, such that participants will engage in a 1-min warm up and a 1-min cool down, with the majority of time (i.e., 23-min) spent exercising at 75% of HRmax.<br>|
| Active Comparator: Trier Social Stress Test for Children<br>The Trier Social Stress Test for Children consists of a speech task in which children must finish a story and a mental arithmetic task, completed in front of a camera and two neutral observers. | Other: Trier Social Stress Test for Children<br>* Participants will be asked to imagine that they are in a new class with 20 other students, and that their teacher has asked them to stand in front of the class and introduce themselves. The mental arithmetic task will entail asking children to serially subtract the number 5 from a larger number as quickly as possible.<br>|
| Placebo Comparator: Seated Rest<br>Participants will sit in a comfortable chair, placed in the same room as the motor-driven treadmill, for a period of 25-min. | Other: Seated Rest<br>* Children will be asked to sit quietly or read a book of their choosing.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neuroelectric outcome | P3 - ERP | baseline | 
| Neuroelectric outcome | P3 - ERP |  1 hr after arriving at lab, after completing the experimental condition | 
| inhibitory control | accuracy | baseline | 
| inhibitory control | reaction time | baseline | 
| working memory | accuracy | baseline | 
| working memory | reaction time | baseline | 
| inhibitory control | accuracy |  1 hr after arriving at lab, after completing the experimental condition | 
| inhibitory control | reaction time |  1 hr after arriving at lab, after completing the experimental condition | 
| working memory | accuracy |  1 hr after arriving at lab, after completing the experimental condition | 
| working memory | reaction time |  1 hr after arriving at lab, after completing the experimental condition | 
| Academic Achievement outcome | WRAT3 (Wide Range, Inc., Wilmington, DE) Reading Accuracy |  1.5 hrs after arriving at lab, after completing the experimental condition | 
| Academic Achievement outcome | WRAT3 (Wide Range, Inc., Wilmington, DE) Spelling Accuracy |  1.5 hrs after arriving at lab, after completing the experimental condition | 
| Academic Achievement outcome | WRAT3 (Wide Range, Inc., Wilmington, DE) Math Accuracy |  1.5 hrs after arriving at lab, after completing the experimental condition |