The brain is the body’s largest consumer of oxygen, utlizing roughly 20% of the total oxygen and consuming 25-30% of total glucose . Even though <10% of the brain’s maximal capacity is active at any given time, the brain utilizes almost all delivered oxygen . In order to perform different tasks or more than one task at a time (multitasking), the oxygen supply is shifted from one region of the brain to another via blood perfusion modulation. These perfusion changes can be easily visualized by functional magnetic resonance tomography (fMRI) technology . Multiple studies have demonstrated that our ability to peform complex activities decreases under oxygen depleted environments.

Brain performance is highly sensitive to any decrease in oxygen supply. A reduction of the plasma oxygen pressure to 65 mmHg will impair the brain’s ability to perform complex tasks. At 55 mmHg, short-term memory will be impaired, and at <35 mmHg consciousness will be lost. At high altitudes or other oxygen depleted environments, cognitive and motor performances are impaired while performing relatively simple tasks.

Improvement in performance of both single and multitasking while in a hyperbaric environment supports the hypothesis that oxygen is indeed a rate limiting factor for brain activity. Hyperbaric oxygenation can serve as an environment for enchancing brain performance.