Balancing Brains

To do this, Paloski will put astronauts in a centrifuge. While they lie comfortably on their sides (the astronauts are tested one at a time), the device spins at varying rates of speed forward and back. After ten minutes of spinning, the astronauts are tested. They stand on a platform inside of a booth. All they have to do is stand as still as possible. But the platform and the booth are designed to isolate the different kinds of sensory information used in balancing - visual, vestibular and proprioceptive. For example, the most important proprioceptive sensors for balance control are the stretch receptors in your ankles, and the platform can prevent the body from receiving that sensory information. "If you begin to sway forward,” explains Paloski, "we move the platform to an angle that's identical to the angle you've moved through, so that your ankle angle never changes."

Image credit: NASA. After a spin in the centrifuge, this test subject steps into the "balance booth," also known as the "posturography system."

By spinning astronauts and then testing them in the "balance booth," Paloski hopes to learn how to facilitate the transition from one state to another. His subjects will be crew members of shuttle mission STS-107, which launched on January 16th 2003. "We plan to test these astronauts both before and after the mission," he says.

Paloski's research might help astronauts regain their sense of balance faster, but there's more to it than that. For instance, a side effect of transitioning between models is motion sickness. Paloski's work could help doctors understand such maladies. It might also be possible to train astronauts to develop models before they're needed. Mars explorers, for example, might be able to generate a 1/3-g model long before they reach the red planet.

And for us on Earth? Paloski's work may help here, too. Ultimately his research is about making it easier to learn - and that's something we do every day of our lives.