A new study has found that long-duration spaceflight results in changes to the human brain, as the brain learns to adapt to its new spacefaring environment.
A team of researchers used MRI scans to monitor the brains of 11 Russian cosmonauts, each who had spent about six months aboard the International Space Station. The scans were taken before, shortly after, and then seven months after their stay on the ISS.
What they found was that the human brain “reorients” itself to accommodate the environment in space, picking up new motor skills and improved coordination suitable for prolonged living in freefall. These changes didn’t result in any neurodegeneration, and at least seven months after the cosmonauts returned home, their brains more or less returned to normal.
“We found increased WM [white matter] in the cerebellum after spaceflight, providing the first clear evidence of sensorimotor neuroplasticity. At the region of interest level, this increase persisted 7 months after return to Earth. We also observe a widespread redistribution of CSF [cerebrospinal fluid], with concomitant changes in the voxel fractions of adjacent GM [gray matter].”
These newly acquired abilities, however, likely persist after returning home, at least for some time. I guess it’s just like riding a bike.
“…it is possible that these partly reverse over time when returning to a 1G environment but also partly sustain as a reflection of long-term skill learning, which supports the observation that frequent flyers perform better at return than first-time flyers.”
We’ve known for a while that prolonged time spent in freefall has numerous effects on the human body, and this isn’t the first study regarding spaceflight’s effects on the human brain (one study found postflight changes in the pituitary gland). Previous studies have also shown that astronauts experience a loss in visual acuity, as well as both bone and muscle degeneration.
After astronaut Scott Kelly returned home from a year on the ISS back in 2016, researchers found that his gene expression had changed when compared to his twin brother Mark Kelly, who had remained on Earth during that time. According to NASA, this change was “likely…within the range for humans under stress, such as mountain climbing or SCUBA diving.”