Ax-2 Crew Conducted Studies During Mission to Understand Human Physiology in Microgravity

Ax-2 Mission Specialist Ali Alqarni uses the Smarting Pro EEG device aboard the ISS to conduct brain studies.

During Axiom Mission 2 (Ax-2), the Ax-2 astronauts measured changes in their eyes, blood pressure, blood oxygen, and heart rate levels, as well as performed some brain imaging studies for the Nebula Human Research investigations. These human research studies observed how humans adapt and respond to spaceflight to better understand human health in microgravity with the goal to offset the long-term effects of living in weightlessness.

EEG Monitoring in Space

By looking at the brain in space, we can learn about the mental health problems astronauts might face on long missions. It also provides a unique setting to unravel the mysteries of our own biology, particularly our brains. Studies conducted in space can offer unique insights and complement our terrestrial research, possibly leading to new breakthroughs in our understanding of neurological and cognitive function.

Long-term space travel has physical and psychological effects on astronauts. Sleep disruptions, stress, and changes in cognition are only some of the issues they face. Continuous EEG monitoring helps assessing astronaut’s cognitive health, stress levels, sleep quality, and mental workload in real-time.

The Smarting Pro EEG device, developed by mbraintrain, was the in-space EEG monitoring system used for the Nebula project during the Ax-2 mission. The crew onboard the ISS used the device to conduct brain studies in microgravity. The data collected could significantly improve safety and performance during extended space missions and identify potential issues early so appropriate countermeasures or treatments are made on time to ensure the safety and well-being of astronauts.

Recording Brain Activity During Spaceflight:

During the Ax-2 mission, a new neuroimaging technology called Functional Near-Infrared Spectroscopy (fNIRS) was used for the first time to record the brain activity of astronauts during spaceflight. A Polish neurotech company, CortiVision, provided its fNIRS Photon Cap wireless system to be used for cognitive experiments that are part of the Nebula project. This is a non-invasive neuroimaging technique measured changes in the cerebral cortex's oxygenated and deoxygenated hemoglobin concentration. 

By using fNIRS, researchers will monitor changes in neural activity in the Ax-2 crew’s brains, which can help to understand better the effects of spaceflight on cognitive and neurological function. Before the mission, the Ax-2 crew performed experimental tasks while the fNIRS monitored different areas of their brain. Then the crew completed the same tasks and gathered measurements during two-time points throughout the mission. After returning to Earth, the Ax-2 astronauts participated in fNIRS measurement one last time. The results will allow researchers to compare whether brain activity patterns change in space travelers during a mission.

The success of the first fNIRS measurement during the Ax-2 mission could open up many new applications to optimize astronaut performance and well-being during space missions. In particular, fNIRS can be applied to study the effects of isolation, confinement, and other psychosocial stressors that astronauts may experience during long-duration missions. Additionally, fNIRS can be used to study astronauts' brain activity during tasks critical for spaceflight, such as piloting a spacecraft or performing repairs on the ISS and, in the future, it may be able to monitor changes in brain physiology during planned expeditions to Mars.

How Microgravity Affects Vision:

Space-associated neuro-ocular syndrome (SANS) is a not well-understood change seen in the eye due to the effects of microgravity on the vision of space travelers. It is a key area to observe when understanding the risk to humans during long spaceflight missions.

Pupillometry is the study of how the pupil of the eye changes in size in response to stimuli and may be a way to study intracranial pressure (ICP, or the pressure inside the skull) in a non-invasive way.

As researchers believe ICP may be linked to SANS, the purpose of the Nebula Biodata Pupillometry study is to get a rapid, easy, and non-invasive measure to infer changes in the pupil as a surrogate measure of ICP. A Pupilometer device was used during the Ax-2 mission to understand how microgravity affects the Ax-2 crew’s vision.