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Not yet recruitingNCT07585227HYPROUpdated May 13, 2026

Study of the Effects of Acute Exposure to Moderate Altitude Hypoxia on Prospective Memory.

An interventional study of Hypoxia exposure and Oxygen administration in Hypoxia, Hypoxia Brain and Hypoxia Altitude Simulation Test, sponsored by Direction Centrale du Service de Santé des Armées. Not yet recruiting at 1 site in France. Open to participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-13.

Sponsored by Direction Centrale du Service de Santé des Armées · Not applicable, Interventional, and Other

Phase
Not applicable
Study type
Interventional
Enrollment
50
Allocation
Randomized
Ages
18 Years to 45 Years
Sex
All
01

Study summary

The goal of this study is to investigate whether prospective memory, i.e., memory for delayed intentions, is impaired at moderate altitude (4,000m).

It will also allow to study the effect of air and oxygen administration during hypoxia exposure.

The main questions it aims to answer are:

  • Does moderate acute hypoxia impair prospective memory ?
  • If so, does air or oxygen adminsitration induce a restoration of prospective memory? Researchers will compare cognitive performance during normobaric hypoxia exposure to cognitive performance during normoxia (control situation).

Participants will:

  • Session S0. Perform a battery of neuropsychological tests and questionnaires). EEG will be recorded during tests. A cheek swab will be performed.
  • Sessions S1 and S2. Perform several cognitive tasks while exposed to hypoxia and to normoxia (2 different sessions, randomized order) in a normobaric chamber. These are standardized cognitive tests administered on a computer and cognitive tests embedded in a flight simulator scenario. Various questionnaires will be performed on a regular basis. Several physiological measurements will be performed continuously: EEG, ECG, SpO2 and breathing rate. Blood pressure will be measured at the beginning and at the end of hypoxia/normoxia exposure. A blood sample will also be performed. At last, participants will inhale air or oxygen through a mask while making a cognitive task in the chamber.
Read the detailed description

Flight crew operate in a dynamic, complex, and uncertain environment that requires them to process a large amount of information from multiple sources under time pressure. To successfully carry out their mission, flight crews must therefore constantly sort, prioritize, and analyze relevant information based on the situation, which requires them to manage their cognitive resources simultaneously-at the risk of experiencing a decline in performance that could significantly compromise aviation safety.

With recent changes in the geostrategic context, the flight profiles of operational missions expose military aircraft crews and onboard operators to a greater risk of in-flight hypoxia. During an acute hypoxic episode, physiological cardiac and respiratory responses are triggered to protect the body-and particularly the brain-from oxygen deprivation. However, these mechanisms are effective only for a limited time. If normoxia is not restored, symptoms will manifest as hypoxemia worsens.

Among flight crew members, impairments in cognitive functions-particularly prospective memory-such as failing to report one's position to other aircraft or failing to retract the flaps before takeoff, are common and can lead to serious accidents. To our knowledge, the effects of hypoxic exposure on this form of memory have not yet been investigated.

02

Conditions studied

  • Hypoxia
  • Hypoxia Brain
  • Hypoxia Altitude Simulation Test
  • Hypoxia in Healthy Individuals
  • Hypoxia, Altitude
  • Hypoxia, Brain
  • Altitude
  • Altitude Hypoxia
  • Normobaric Hypoxia

Keywords

  • prospective memory
  • working memory
  • flight simulator
03

Who can participate

Ages eligible
18 Years to 45 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Healthy volunteer
  • Has provided informed consent

Exclusion criteria

Exclusion Criteria:

  • Individuals who do not understand French
  • Pregnant or breastfeeding women
  • Cardiovascular risk factor
  • Infectious disease within the last 4 weeks
  • Chronic cardiovascular, respiratory, hematological, neurological, psychiatric, or metabolic disease
  • History of epileptic seizures, convulsions, or loss of consciousness
  • Individuals with migraines
  • History of a bleeding disorder
  • History of high blood pressure
  • Current medication use (excluding contraception)
  • History of episodes of altitude intolerance
  • Stay at high altitude (> 3,500 m) within the last 3 months
  • Anxiety score on the Hospital Anxiety and Depression (HAD) scale > 7
  • Depression score on the HAD scale > 7
  • Uncontrollable claustrophobia or a history of panic attacks
04

Study design

Phase
Not applicable
Primary purpose
Other
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Double (Participant, Outcomes assessor)
Enrollment
50 participants (estimated)

Study arms

  • Experimental
    Normoxia-Air + Hypoxia-Air

    S1 = Normoxia exposure + air administration S2 = Hypoxia exposure + air administration

    Other: Hypoxia exposure · Other: Air administration · Behavioral: Standardized cognitive tests (on a computer) · Device: Physiological measurements · Biological: Blood sample · Behavioral: Cognitive tests embedded in a flight simulator scenario

  • Experimental
    Hypoxia-Air + Normoxia-Air

    S1 = Hypoxia exposure + air administration S2 = Normoxia exposure + air administration

    Other: Hypoxia exposure · Other: Air administration · Behavioral: Standardized cognitive tests (on a computer) · Device: Physiological measurements · Biological: Blood sample · Behavioral: Cognitive tests embedded in a flight simulator scenario

  • Experimental
    Normoxia-O2 + Hypoxia-O2

    S1 = Normoxia exposure + oxygen administration S2 = Hypoxia exposure + oxygen administration

    Other: Hypoxia exposure · Drug: Oxygen administration · Behavioral: Standardized cognitive tests (on a computer) · Device: Physiological measurements · Biological: Blood sample · Behavioral: Cognitive tests embedded in a flight simulator scenario

  • Experimental
    Hypoxia-O2 + Normoxia-O2

    S1 = Hypoxia exposure + oxygen administration S2 = Normoxia exposure + oxygen administration

    Other: Hypoxia exposure · Drug: Oxygen administration · Behavioral: Standardized cognitive tests (on a computer) · Device: Physiological measurements · Biological: Blood sample · Behavioral: Cognitive tests embedded in a flight simulator scenario

Interventions

  • OtherHypoxia exposure

    Normobaric hypoxia exposure (FiO2 = 12,6%, equivalent to 4,000m) during 4h

  • DrugOxygen administration

    Oxygen administration (FiO2 = 100%) through a mask during 10 minutes

  • OtherAir administration

    Air administration (Fi02 = 21%) through a mask during 10 minutes

  • BehavioralStandardized cognitive tests (on a computer)

    Auditory oddball, visual oddball, event-based prospective memory, time-based prospective memory, n-back.

  • DevicePhysiological measurements

    EEG, ECG, SpO2, breathing rate, eyetracking, blood pressure

  • BiologicalBlood sample

    A blood sample is collected for mitochondrial breathing analyses

  • BehavioralCognitive tests embedded in a flight simulator scenario

    Event-based prospective memory and time-based prospective memory. Prepar3D flight simulator.

05

What researchers measure

Primary outcomes

  1. Change in event-based prospective memory accuracy between hypoxia and normoxia conditions

    Accuracy (%) = Prospective memory target detection rate (number of targets correctly responded to / total number of targets presented × 100)

    Time frame: Through study completion, an average of 1 month

06

Study locations

1 site
07

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT07585227
Lead sponsor
Direction Centrale du Service de Santé des Armées
Responsible party
Sponsor
First posted
May 13, 2026
Start date
May 6, 2026 (estimated)
Primary completion
Dec 31, 2026 (estimated)
Completion
Dec 31, 2026 (estimated)
Last update
May 13, 2026

Study contacts

Carine MALLE, PhD
Contact
carine.malle@gmail.com
178651479 ext. 33
Fabien SAUVET, MD, PhD
Contact
fabien.sauvet@gmail.com

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
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