DEFYING GRAVITY

Study Reveals What Space Does to Astronauts’ Brains

The study has broad implications regarding the effects of spaceflight on the human anatomy.

A new study has found that astronauts’ brains can be repositioned and reshaped during stints in outer space. Published in the journal Proceedings of the National Academy of Sciences, the study found that during spaceflight, the brain shifts upward and backward within the skull compared to its normal position on Earth. The most affected regions were sensory and motor-related—linked to loss of balance, motion sickness, and disorientation. “The people who went for a year showed the largest changes,” said co-author Rachael Seidler, a professor in the department of applied physiology and kinesiology at the University of Florida. “There were still some changes evident in people who went for two weeks, but duration seems to be the driving factor.” The study analyzed MRI scans from 26 astronauts before and after their spaceflights, with time in space ranging from a few weeks to six months. Although some astronauts experienced minor “sensory conflicts” in space, the study did not find serious symptoms such as headaches during or after spaceflight. “We need to understand these changes and their impacts to keep astronauts safe and healthy and protect their longevity,” Seidler said.