(Web Desk) - A surprising change affects the minds of astronauts while on trips to space.
Space heroes who spent an average of six months on International Space Station were analysed as part of a groundbreaking study.
And it turned out that astronauts experienced a temporary slowing of "cognitive performance".
Importantly, some of these changes didn't resolve until the astronauts were back down on Earth.
Scientists have known for a while about the difficulties on the human body, including radiation exposure, bone density loss, and difficulties sleeping.
But now scientists have shown that cognitive performance of astronauts can suffer in space too.
Researchers analysed 25 astronauts, putting them through a series of tests.
That include measuring their speed and accuracy at different points.
That included before the mission, early and late in the flight, as well as 10 and 30 days after landing.
They found that astronauts responded slower in terms of speed, working memory, and attention compared to when on Earth. But the astronauts weren't less accurate.
"Cognitive performance was generally stable over time with some differences observed across mission phases for specific subtests," the study, published in Frontiers in Physiology, explained.
"There was slowed performance observed in early flight on tasks of processing speed, visual working memory, and sustained attention.
"We observed a decrease in risk-taking propensity during late flight and post-flight mission phases.
It added: "Exploratory analyses yielded no clear pattern of associations between cognitive performance and either sleep or ratings of alertness."
Importantly, however, scientists noted that there was no evidence of brain damage – or permanent cognitive troubles.
"We show that there is no evidence of any significant cognitive impairment or neurodegenerative decline in astronauts spending six months on the ISS," said Dr. Sheena Dev, a researcher at Nasa's Behavioral Health and Performance Laboratory.
"Living and working in space was not associated with widespread cognitive impairment that would be suggestive of significant brain damage."
Sadly, the study didn't reveal exactly why the changes occurred.
It's possible that it may be linked to stress, researchers said. "Even on Earth, processing speed, working memory, and attention are cognitive domains that can show temporary changes when an individual is under stress," Dev explained.
"Other domains, such as memory, are less vulnerable to stressors.
"For example, if you happen to have a really busy day but couldn't get much sleep the night before, you might feel like it's hard to pay attention or that you need more time to complete tasks
"We found that the most vulnerable domains while astronauts are aboard the ISS are the same as those that are more susceptible to stressors on Earth."