MRIs before and after space missions reveal that astronauts' brains compress and expand during spaceflight, according to research done by Movement Science professor Rachael Seidler. Dr. Seidler is director of U-M School of Kinesiology's Neuromotor Behavior Laboratory.
The study, believed to be the first to examine structural changes that take place in astronauts' brains during spaceflight, found that the volume of gray matter increased or decreased, and the extent of the alteration depended on the length of time spent in space.
Seidler and her colleagues examined structural MRIs in 12 astronauts who spent two weeks as shuttle crew members, and 14 who spent six months on the International Space Station. All experienced increases and decreases in gray matter in different parts of the brain, with more pronounced changes the longer the astronauts spent in space.