Cognitive and Perceptual Deficits of Normobaric Hypoxia and the Time Course to Performance Recovery
BACKGROUND: Many in-flight hypoxia-like incidents involve exposure to normobaric hypoxia following an oxygen delivery equipment failure. Studies have documented the effect of hypoxia on specific aspects of human performance. The goal of the present study was to establish the
effects of acute hypoxia on cognitive, psychomotor, and perceptual abilities and to chronicle the time required for these capabilities to fully recover to pre-exposure levels.
METHODS: Subjects were presented with a battery of tests designed to assess visual acuity, contrast sensitivity, color vision, executive control, and reaction time (simple reaction time, SRT, and choice reaction time, CRT) before, during, immediately following, 60 min, 120 min, and 24 h after hypoxic exposure. Oxygen saturation was continuously measured throughout the duration of the study using near-infrared spectroscopy measured on the forehead and finger pulse oximetry.
RESULTS: During the course of six assessment periods, contrast sensitivity, color vision, and subjective workload were affected to varying degrees during hypoxic exposure, but returned to baseline levels soon after a return to normoxia. Conversely, reaction time values and regional cerebral oxygen saturation (MrSO2 ), while also affected during hypoxic exposure (MSRT = 362.17 ms, MCRT = 389.55 ms, MrSO2 = 79.36%), did not return to baseline levels (MSRT = 337.35 ms, MCRT = 372.75 ms, MrSO2 = 99.75%) until the assessment period 24 h following exposure (MSRT = 324.35 ms, MCRT = 366.22 ms, MrSO2 = 99.10%).
DISCUSSION: Evidence from this study suggests an impairment of specific performance characteristics following hypoxic exposure – some for a considerable period of time. Mitigation efforts should focus more on the prevention of hypoxia exposure rather than relying exclusively on training operators to recognize and react earlier to hypoxic symptomology.
Phillips JB, Hørning D, Funke ME. Cognitive and perceptual deficits of normobaric hypoxia and the time course to performance recovery. Aerosp Med Hum Perform. 2015; 86(4):357–365.
METHODS: Subjects were presented with a battery of tests designed to assess visual acuity, contrast sensitivity, color vision, executive control, and reaction time (simple reaction time, SRT, and choice reaction time, CRT) before, during, immediately following, 60 min, 120 min, and 24 h after hypoxic exposure. Oxygen saturation was continuously measured throughout the duration of the study using near-infrared spectroscopy measured on the forehead and finger pulse oximetry.
RESULTS: During the course of six assessment periods, contrast sensitivity, color vision, and subjective workload were affected to varying degrees during hypoxic exposure, but returned to baseline levels soon after a return to normoxia. Conversely, reaction time values and regional cerebral oxygen saturation (MrSO2 ), while also affected during hypoxic exposure (MSRT = 362.17 ms, MCRT = 389.55 ms, MrSO2 = 79.36%), did not return to baseline levels (MSRT = 337.35 ms, MCRT = 372.75 ms, MrSO2 = 99.75%) until the assessment period 24 h following exposure (MSRT = 324.35 ms, MCRT = 366.22 ms, MrSO2 = 99.10%).
DISCUSSION: Evidence from this study suggests an impairment of specific performance characteristics following hypoxic exposure – some for a considerable period of time. Mitigation efforts should focus more on the prevention of hypoxia exposure rather than relying exclusively on training operators to recognize and react earlier to hypoxic symptomology.
Phillips JB, Hørning D, Funke ME. Cognitive and perceptual deficits of normobaric hypoxia and the time course to performance recovery. Aerosp Med Hum Perform. 2015; 86(4):357–365.
Keywords: human performance; hypoxia; normobaric hypoxia; performance recovery
Document Type: Research Article
Publication date: 01 April 2015
- This journal (formerly Aviation, Space, and Environmental Medicine), representing the members of the Aerospace Medical Association, is published monthly for those interested in aerospace medicine and human performance. It is devoted to serving and supporting all who explore, travel, work, or live in hazardous environments ranging from beneath the sea to the outermost reaches of space. The original scientific articles in this journal provide the latest available information on investigations into such areas as changes in ambient pressure, motion sickness, increased or decreased gravitational forces, thermal stresses, vision, fatigue, circadian rhythms, psychological stress, artificial environments, predictors of success, health maintenance, human factors engineering, clinical care, and others. This journal also publishes notes on scientific news and technical items of interest to the general reader, and provides teaching material and reviews for health care professionals.
To access volumes 74 through 85, please click here. - Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- Submit Articles
- Ingenta Connect is not responsible for the content or availability of external websites
Receive new issue alert- Access Key
- Free content
- Partial Free content
- New content
- Open access content
- Partial Open access content
- Subscribed content
- Partial Subscribed content
- Free trial content