The Role of Breathing Perception in Respiratory Control

NCT07470099 | Not Yet Recruiting

• 2 other identifiers: 28381- Aim 2FOAAFRLAFOSR20240007
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Work of Breathing

Keywords

Dyspnea Perception; Cognitive Performance; Auditory Distraction

Outcome Measures

Primary Outcomes (4)

• Change in Stroop Color-Word Test Time Performance

  Time performance on the Stroop Color-Word Test (min:sec) will be measured every 10 minutes during each breathing task.

  Before and after each Day 1 breathing task (approximately 60 minutes in duration)

• Change in Stroop Color-Word Test Error Performance

  The number of errors on the Stroop Color-Word Test will be measured will be measured every 10 minutes during each breathing task.

  Before and after each Day 1 breathing task (approximately 60 minutes in duration)

• Change in Perception of Dyspnea Intensity

  Participants will rate perception of dyspnea (breathing) intensity on a visual analog scale (VAS) every 5 minutes during each breathing task. The participant will draw a vertical marker line on a horizontal line (100mm), indicating their breathing perception from "not noticeable" (0mm) to "maximal imaginable intensity" (100mm).

  Before and after each Day 1 breathing task (approximately 60 minutes in duration)

• Change in Perception of Dyspnea Unpleasantness

  Participants will rate perception of dyspnea (breathing) unpleasantness on a visual analog scale (VAS) every 5 minutes during each breathing task. The participant will draw a vertical marker line on a horizontal line (100mm), indicating their breathing perception from "not unpleasant" (0mm) to "maximal imaginable unpleasantness" (100mm).

  Before and after each Day 1 breathing task (approximately 60 minutes in duration)

Secondary Outcomes (8)

• Change in Diaphragm Thickness

  Before and after each Day 1 breathing task (approximately 60 minutes in duration)

• Change in Heart Rate Variability

  Before and after each Day 1 breathing task (approximately 60 minutes in duration)

• Change in Peripheral Oxygen Saturation

  Before and after each Day 1 breathing task (approximately 60 minutes in duration)

• Change in Blood Pressure - Brachial Artery

  Before and after each Day 1 breathing task (approximately 60 minutes in duration)

• Change in Blood Pressure - Finger Photoplethysmography

  Before and after each Day 1 breathing task (approximately 60 minutes in duration)

Study Arms (6)

Ambient noise, then music distraction, then increased ventilation auditory feedback

ACTIVE COMPARATOR

Participants will complete 3 full length breathing tasks, one under each auditory condition. The order of condition exposure will be assigned via randomization.

Other: Ambient Noise; Other: Increased Auditory Feedback; Other: Noise Distraction

Ambient noise, then increased ventilation auditory feedback, then music distraction

ACTIVE COMPARATOR

Participants will complete 3 full length breathing tasks, one under each auditory condition. The order of condition exposure will be assigned via randomization.

Other: Ambient Noise; Other: Increased Auditory Feedback; Other: Noise Distraction

Music distraction, then ambient noise, then increased ventilation auditory feedback

ACTIVE COMPARATOR

Participants will complete 3 full length breathing tasks, one under each auditory condition. The order of condition exposure will be assigned via randomization.

Other: Ambient Noise; Other: Increased Auditory Feedback; Other: Noise Distraction

Increased ventilation auditory feedback, then ambient noise, then music distraction

ACTIVE COMPARATOR

Participants will complete 3 full length breathing tasks, one under each auditory condition. The order of condition exposure will be assigned via randomization.

Other: Ambient Noise; Other: Increased Auditory Feedback; Other: Noise Distraction

Increased ventilation auditory feedback, then music distraction, then ambient noise

ACTIVE COMPARATOR

Participants will complete 3 full length breathing tasks, one under each auditory condition. The order of condition exposure will be assigned via randomization.

Other: Ambient Noise; Other: Increased Auditory Feedback; Other: Noise Distraction

Music distraction, then increased ventilation auditory feedback, then ambient noise

ACTIVE COMPARATOR

Participants will complete 3 full length breathing tasks, one under each auditory condition. The order of condition exposure will be assigned via randomization.

Other: Ambient Noise; Other: Increased Auditory Feedback; Other: Noise Distraction

Interventions

Ambient Noise OTHER

Participants will complete the breathing task with ambient (or normal) auditory feedback (\~10 decibels).

Ambient noise, then increased ventilation auditory feedback, then music distraction; Ambient noise, then music distraction, then increased ventilation auditory feedback; Increased ventilation auditory feedback, then ambient noise, then music distraction; Increased ventilation auditory feedback, then music distraction, then ambient noise; Music distraction, then ambient noise, then increased ventilation auditory feedback; Music distraction, then increased ventilation auditory feedback, then ambient noise

Increased Auditory Feedback OTHER

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.

Ambient noise, then increased ventilation auditory feedback, then music distraction; Ambient noise, then music distraction, then increased ventilation auditory feedback; Increased ventilation auditory feedback, then ambient noise, then music distraction; Increased ventilation auditory feedback, then music distraction, then ambient noise; Music distraction, then ambient noise, then increased ventilation auditory feedback; Music distraction, then increased ventilation auditory feedback, then ambient noise

Noise Distraction OTHER

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).

Ambient noise, then increased ventilation auditory feedback, then music distraction; Ambient noise, then music distraction, then increased ventilation auditory feedback; Increased ventilation auditory feedback, then ambient noise, then music distraction; Increased ventilation auditory feedback, then music distraction, then ambient noise; Music distraction, then ambient noise, then increased ventilation auditory feedback; Music distraction, then increased ventilation auditory feedback, then ambient noise

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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)

You may not qualify if:

• 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)

Sponsors & Collaborators

• Indiana University: lead
• United States Department of Defense: collaborator

Study Sites (1)

Multidisciplinary Engineering and Sciences Hall (MESH)

Bloomington, Indiana, 47405, United States

Location

Central Study Contacts

Timothy D Mickleborough, PhD

CONTACT

812-855-0753; tmickleb@iu.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: March 10, 2026
• First Posted: March 13, 2026
• Study Start (Estimated): June 1, 2027
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): September 30, 2028
• Last Updated: March 13, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)