When astronauts go into space, the lack of gravity there causes weird changes in their bodies.
For example, without gravity, fluids in the body sort of just float around inside the body and get more equally distributed than they would than while subjected to the gravity on Earth.. This explains why astronaut's faces look a little puffy when you see them floating around inside the International Space Station.
However, it's what happens inside the brain that now fascinates both NASA and the ESA. All that fluid in the head probably has some interesting effects. For example, take the inner ear system that usually lets someone know if they're falling or not. In space, without gravity, that vestibular system always feel like it's falling and tells the brain that. But the visual system, what the astronaut sees, tells a completely different story. This often results in dizziness.
However, for astronauts, the news is good: the brain eventually adapts to the new microgravity conditions. And those astronauts who spend more time in space adapt more quickly.
That doesn't mean that mental functions aren't affected by microgravity: NASA's previous research shows that astronauts have a harder time controlling their movements, as well as having a more difficult time functioning when assigned cognitive tasks.
Both NASA and the ESA hope to study how microgravity affects the brain more thoroughly by taking MRI scans of astronaut's brains before and after spaceflight. Some of these scans will happen while the astronauts engage in cognitive activities, so scientists can study how microgravity affects the brain's actual functioning.
Of course, this research is important in helping astronauts cope once we're ready to tackle longer periods in space, perhaps something like a trip to Mars. Now that longer trips into deep space have become a hot topic, knowing how microgravity affects not just the body, but the brain, can help scientists assist astronauts in better preparing for those longer journeys.
But this isn't just about understanding what happens during spaceflight: this research could also help those here on Earth suffering from illnesses such as vertigo or from other issues caused by changes in the brain.
"The research on astronauts is an ethical way to look at people's brains before and after a stressful incident," says ESA principal investigator Professor Floris Wuyts. "Ideally, we would have brain scans of people when they were healthy and after they started suffering from a disorder, because then we can see where the changes have taken place. But such an ideal situation does not exist, and neither can we give subjects a traumatic experience on purpose, of course."