The Role of Breathing Perception in Respiratory Control
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Ambient Noise, Increased Auditory Feedback, Noise Distraction.
- Who it may be relevant to
- Registry conditions: Work of Breathing. Basic parameters: 18 years — 40 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Optimizing Mind-Body Interactions in Respiratory Control During Operationally Relevant Environmental Stressors
Overview
Warfighters are frequently exposed to environments and life-support systems that increase breathing resistance and the work of breathing (WOB), such as aircraft on-board oxygen generation systems and underwater breathing apparatuses. Elevated WOB then increases the perception of breathing difficulty (dyspnea) and has been associated with impaired cognitive performance, including slower reaction time and reduced accuracy during attention-demanding tasks. These effects are particularly concerning in operational settings that require rapid decision-making and precise motor responses. Despite growing recognition of this issue, critical gaps remain regarding strategies to mitigate the perceptual and cognitive consequences of elevated inspiratory resistance, especially under realistic operational stressors. The objective of this experiment is to determine whether modifying the sensory perception of breathing alters breathing perception and cognitive performance during inspiratory resistance. Auditory feedback of ventilation will be manipulated (normal, reduced, or amplified) to assess whether altering breathing-related sensory input affects breathing perception and cognitive performance without changing mechanical load.
Detailed description
In some instances, reducing inspiratory resistive loads (e.g., OBOGs, SCUBA) for Warfighters may not be feasible, but understanding how breathing perception is affected by resistance is essential. Auditory feedback of ventilation significantly influences breathing awareness, and as the WOB increases, this perception intensifies due to enhanced auditory input. This heightened awareness can distract and tax cognitive processing. Recent studies indicate that auditory distractions, like music during exercise, can lessen dyspnea and respiratory and whole-body discomfort in healthy individuals and those with chronic obstructive pulmonary disease. This effect may stem from reduced auditory feedback or improved emotional states linked to music. However, a key knowledge gap exists: it is unclear whether reducing auditory feedback of ventilation during increased inspiratory resistance affects breathing perception and cognitive function. The study will assess the impact of different auditory feedback of ventilation conditions (normal, eliminated via noise distraction, and amplified) on cognitive function under high inspiratory resistance. It's hypothesized that reducing auditory feedback of ventilation will not alter the WOB but will decrease breathing perception and enhance cognitive performance compared to standard or amplified feedback.
Participants will complete two study visits: a screening/familiarization visit (Study Day 0) followed by one experimental visit (Study Day 1). Participants will be instructed to avoid caffeine, alcohol, stimulant medication, pain/anti-inflammatory medication, cannabis and cannabis related products, and vigorous exercise for at least 24 hours prior to experimental visits. On Study Day 0, participants will complete a short familiarization breathing task in which they will breathe for 10 minutes through an 8-10mm hole at the end of a customized device, generating a pre-determined inspiratory resistance of 6-9.5 centimeters of water per liter per second (cmH2O/L/s). During the breathing task, cerebral vascular, cardiovascular and autonomic activity responses will be measured. Every 5 minutes during the breathing test, participants will be asked to rate breathing intensity and unpleasantness, and perform an inspiratory capacity maneuver. Cognitive assessments will be administered every 10 minutes. After the breathing task, participants will complete lung and respiratory muscle function tests.
Prior to Study Day 1 (the experimental visit), participants will be randomized to the order in which they are exposed to the interventional conditions (ambient/normal auditory feedback, enhanced auditory feedback, or removed auditory feedback with replacement of a self-selected music playlist). Upon arrival, an esophageal balloon will be placed to measure the pressure around the heart and lungs. Participants will then complete three full-length breathing tasks, in which they inspire against a predetermined resistive load for 60 minutes, with auditory conditions in the order of randomization. Biometric monitoring, cognitive tasks and participant ratings during the breathing tasks will be completed with the same frequency as Study Day 0. A 1-hour rest period will be observed between the breathing tasks.
Interventions
- Other Ambient Noise
Participants will complete the breathing task with ambient (or normal) auditory feedback (\~10 decibels). - Other Increased Auditory Feedback
Participants will complete the breathing task with increased auditory feedback of ventilation (\~70 decibels). Specifically, a small microphone will be placed in the device that participants breathe through to increase the sound of the participants breath. - Other Noise Distraction
Participants will complete the breathing task without auditory feedback of ventilation. Specifically, participants will wear noise cancelling headphones and will listen to a self-selected music playlist at a constant volume (\~80 decibels).
Primary outcome measures
- Change in Stroop Color-Word Test Time Performance [Time frame: Before and after each Day 1 breathing task (approximately 60 minutes in duration)]
- Change in Stroop Color-Word Test Error Performance [Time frame: Before and after each Day 1 breathing task (approximately 60 minutes in duration)]
- Change in Perception of Dyspnea Intensity [Time frame: Before and after each Day 1 breathing task (approximately 60 minutes in duration)]
- Change in Perception of Dyspnea Unpleasantness [Time frame: Before and after each Day 1 breathing task (approximately 60 minutes in duration)]
Secondary outcome measures (8)
- Change in Diaphragm Thickness [Time frame: Before and after each Day 1 breathing task (approximately 60 minutes in duration)]
- Change in Heart Rate Variability [Time frame: Before and after each Day 1 breathing task (approximately 60 minutes in duration)]
- Change in Peripheral Oxygen Saturation [Time frame: Before and after each Day 1 breathing task (approximately 60 minutes in duration)]
- Change in Blood Pressure - Brachial Artery [Time frame: Before and after each Day 1 breathing task (approximately 60 minutes in duration)]
- Change in Blood Pressure - Finger Photoplethysmography [Time frame: Before and after each Day 1 breathing task (approximately 60 minutes in duration)]
- Change in Heart Rate [Time frame: Before and after each Day 1 breathing task (approximately 60 minutes in duration)]
- Change in Cerebral Blood Oxygen Kinetics [Time frame: Before and after each Day 1 breathing task (approximately 60 minutes in duration)]
- Change in Cerebral Blood Velocity [Time frame: Before and after each Day 1 breathing task (approximately 60 minutes in duration)]
Eligibility criteria
Inclusion criteria
- Between the ages of 18-40 years old.
- English speaking and reading.
- Self-reported weekly activity of at least 120 minutes/week of high intensity exercise for the previous 2 years.
- Normal pulmonary function assessed by a resting forced expiratory volume in 1 second over forced vital capacity (FEV1/FVC) > 75% of predicted.
- Normal cognitive function assessed using the Montreal cognitive function test \[18\].
- Body mass index (BMI) ≤ 35 kg/m2.
- Females with a regular menstrual cycle that ranges from 21-35 days (eumenorrhea)
Exclusion criteria
- History of smoking or recreational smoking, cardiovascular disease, renal disease, pulmonary disease (including asthma or exercise-induced asthma), neurological disease, and metabolic disease.
- Are pregnant or could possibly be pregnant by self-report.
- Are color blind.
- Known allergy or hypersensitivity latex.
- Take selective serotonin reuptake inhibitors, stimulant medication, antibiotics, and chronically consume pain medication (Aleve, Tylenol, etc.).
- Resting blood pressure of > 130mmHg systolic or 90 mmHg diastolic and/or resting pulse rate of > 100 bpm.
- Females with irregular menstrual cycles (oligomenorrhea) that ranges from 36-90 days, and females with the absence of a menstrual cycle (amenorrhea).
- Taking birth control for the sole purpose of period cessation (eg., Mirena IUD)
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Randomized
- Model
- Crossover
- Masking
- Open label
- Primary purpose
- Basic science
Study locations
United States · 1 center
- Multidisciplinary Engineering and Sciences Hall (MESH) — Bloomington
Identifiers
NCT: NCT07470099 · 28381- Aim 2 · FOAAFRLAFOSR20240007