Astronauts aboard the International Space Station (ISS) had reduced memory, attention and processing speed after six months, raising concerns about the impact of cognitive impairment on future space missions to Mars.
The extreme environment of space, with reduced gravity, harsh radiation and the lack of regular sunrises and sunsets, can have dramatic effects on astronaut health, from muscle loss to an increased risk of heart disease. However, the cognitive effects of long-term space travel are less well documented.
Now, at NASA鈥檚 Johnson Space Center in Houston, Texas, and her colleagues have looked at the cognitive performance of 25 astronauts during their time on the ISS.
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The team put the astronauts through the same set of 10 tests both on Earth and on the ISS. These were repeated once before, twice during and twice after the mission, within 10 and 30 days of landing. These tests measured certain cognitive capacities, such as finding patterns on a grid to test abstract reasoning or choosing when to stop an inflating balloon before it pops to test risk-taking.
The researchers found that the astronauts took longer to complete tests measuring processing speed, working memory and attention on the ISS than on Earth, but they were just as accurate. While there was no overall cognitive impairment or lasting effect on the astronauts鈥� abilities, some of the measures, like processing speed, took longer to return to normal after they came back to Earth.
Having clear data on the cognitive effects of space travel will be crucial for future human spaceflight, says at Birkbeck, University of London, but it will be important to collect more data, both on Earth and in space, before we know the full picture.
鈥淎 mission to Mars is not only longer in terms of time, but also in terms of autonomy,鈥� says Ferr猫. 鈥淧eople there will have a completely different interaction with ground control because of distance and delays in communication, so they will need to be fully autonomous in taking decisions, so human performance is going to be key. You definitely don鈥檛 want to have astronauts on Mars with slow reaction time, in terms of attention-related tasks or memory or processing speed.鈥�
It isn鈥檛 surprising that there were some specific decreases in cognitive performance given the unusual environment of space, says at the University of East Anglia in Norwich, UK. 鈥淚t鈥檚 not necessarily a great cause for an alarm, but it鈥檚 something that鈥檚 useful to be aware of, especially so that you know your limits when you鈥檙e in these extreme environments,鈥� she says.
That awareness could be especially helpful for astronauts on longer missions, adds Bower. 鈥淚t鈥檚 not just how you do in those tests, but also what your perception of your ability is,鈥� she says. 鈥淲e know, for example, if you鈥檙e sleep deprived, that quite often your performance will decline, but you won鈥檛 realise your performance has declined.鈥�
Frontiers in Physiology
