Studying fighter pilot physiology could help us understand astronaut brains

Brain connections change for pilots with more experience, according to new study.
A Belgian F-16 jet fighter takes part in the NATO Air Nuclear drill "Steadfast Noon" (its regular nuclear deterrence exercise) at the Kleine-Brogel air base in Belgium on October 18, 2022. KENZO TRIBOUILLARD/AFP via Getty Images

Blasting off into space poses huge demands on the brain and the rest of the body. Astronauts  must face the immense g-forces–or G’s–present during blast-off, while rapidly interpreting often conflicting sensory and visual stimuli, all while controlling a very complex vehicle at extreme speeds.

All in all, it requires a lot of multitasking and is incredibly taxing. Previous research has suggested that the brain may undergo changes to the structure and function of the brain following space flight and astronaut training, also known as neural plasticity.

[Related: I flew in an F-16 with the Air Force and oh boy did it go poorly.]

To better understand how the stresses of space travel affects the body, scientists are studying fighter pilots, since they can face similar physiological stresses during flight. Fighter pilots feel G forces (one “G” is equal to the force of gravity we all feel sitting on Earth, and pilots can experience as many as 9 Gs during flight) when a jet accelerates or turns quickly. During those maneuvers, their blood can drain away from their brains. To handle these moments, fighter pilots perform an anti-G exercise and wear special compression suits that prevents blood from pooling in the legs. If they don’t manage the Gs correctly, they could pass out and crash.

In a study published February 15 in the journal Frontiers in Physiology, researchers from the University of Antwerp in Belgium examined the brains of 10 F16 fighter pilots from the Belgian Air Force to learn more about what is happening to astronauts. 

“Fighter pilots have some interesting similarities with astronauts, such as exposure to altered g-levels, and the need to interpret visual information and information coming from head movements and acceleration (vestibular information),” said study co-author Floris Wuyts and head of the Lab for Equilibrium Investigations and Aerospace (LEIA) at the University of Antwerp, in a statement. “By establishing the specific brain connectivity characteristics of fighter pilots, we can gain more insight into the condition of astronauts after spaceflight.”

They conducted MRIs of the brains of 10 fighter pilots and a control group of 10 non-pilots to look at the functional brain connectivity in fighter pilots for the first time.

The scans revealed that pilots who had more flight experience had specific brain connectivity patterns in areas related to processing sensorimotor information—this included diminished  connectivity in certain areas of the brain that process sensorimotor information. According to the team, this could indicate that the brain is adapting to cope with the extreme conditions experienced during flight and changes in the brain occur with an increased number of flight hours. 

[Related: Two fighter pilots passed out over Nevada last year. Software saved them both.]

The experienced pilots had more complicated connectivity in frontal areas of the brain that process vestibular and visual information compared to their non-flying peers. These regions are likely involved in the huge cognitive demands when flying a complicated jet, such as processing multiple and occasionally conflicting stimuli at once and to prioritize the most important stimuli, such as reading cockpit instruments. 

“By demonstrating that vestibular and visual information is processed differently in pilots compared to non-pilots, we can recommend that pilots are a suitable study group to gain more insight into the brain’s adaptations toward unusual gravitational environments, such as during spaceflight,” said study co-author Wilhelmina Radstake, a researcher at LEIA, in a statement.

The findings in this study will help researchers better understand the effects of space flight on the brain and the team hopes to use it to create better pre-flight training programs for fighter pilots or astronauts.