CU Boulder finds possible solution to motion sickness in space

Mar. 15—About 70% of astronauts will suffer from motion sickness during the first few days of orbital flight, experiencing dizziness, cold sweating, nausea and vomiting, according to a journal article in the National Institutes of Health.

To solve this problem, researchers at the University of Colorado Boulder used virtual reality headsets and spinning machines that simulate space flight.

Torin Clark, a CU Boulder professor in aerospace engineering, said people get motion sick when the brain receives unexpected sensory information about how they're moving.

"Let's say you're riding in the back of the car. You might get a bunch of passive motion your brain isn't expecting that can lead to motion sickness," Clark said. "For astronauts, this happens because they're going through a gravity transition, whether it's going into space or coming back from space."

Astronaut's brains are programmed to expect one Earth gravity, which they've experienced their whole life. In space that changes, causing motion sickness. Eventually, the astronauts adapt to it, but when they come back they get motion sickness again because of the change.

"There's sort of this incongruency between what the brain's expecting and what sensory information they're actually getting, so that leads to motion sickness both going into space and coming back from space," Clark said.

The researchers' goal was to provide sensory information to reduce that difference. They created machines that spin a person around in a way that simulates the experiences astronauts have when they go to space and experience gravity changes, specifically focusing on what happens during water landings.

"We are essentially trying to replicate the gravity transition and the wave-like motion," Graduate Research Assistant Taylor Lonner said.

While in the machine simulations, two groups were given a virtual reality headset with different images. The control group saw a black screen with a white dot in the middle that didn't move, and the experimental group had a forest scene that moved accurately with how they moved in the machine to try to reduce the sensory differences between the brain and body.

Only 34% of the control group could stay in the machine for the hour-long experiment without being pulled due to intense motion sickness, and roughly 79% of the experimental group made it through the full hour.

"Your brain is either expecting no movement cues because it doesn't see any motion cues and it's not expecting anything, or it expects motion cues because it feels motion cues," Lonner said. "So there's that disagreement there, and by providing visual cues that represent your accurate motion, you are reducing the amount of incongruency your brain is experiencing. As a result, that reduces motion sickness."

While the team didn't test for land-based motion sickness, Clark said it's likely that providing accurate visual cues of self-motion can help reduce sensory conflict, and thus help mitigate motion sickness. In some cases, like riding in the front of a car, these visual cues are already available and motion sickness can be reduced by looking out the window. In other cases, like an airplane or below deck on a ship, there aren't great visual cues, and using virtual reality to provide a wide field of view could be beneficial.

Motion sickness is a problem for astronauts, Clark said, because vomiting within the spacesuit could asphyxiate them. It also causes them to be more tired, lethargic and less able to respond at their peak capabilities to any problems or emergencies.

"Keeping our astronauts safe at every part of the mission, regardless of the mission, is really important," Lonner said.