Space Station Study Shows Astronauts Process Tasks More Slowly, But Maintain Accuracy

The largest cognitive performance study of professional astronauts to date reveals that while some mental processes slow down during six-month stays on the International Space Station, overall cognitive function remains stable with no signs of lasting impairment.

Published in Frontiers in Physiology | Estimated reading time: 6 minutes

Space presents extreme challenges to the human body, with astronauts facing radiation exposure, altered gravity, demanding work conditions, and disrupted sleep patterns. In a new study examining how these factors affect cognitive performance, researchers at NASA’s Behavioral Health and Performance Laboratory tested 25 astronauts before, during, and after their ISS missions.

“We show that there is no evidence of any significant cognitive impairment or neurodegenerative decline in astronauts spending six months on the ISS,” explains Dr. Sheena Dev, the study’s lead author. “Living and working in space was not associated with widespread cognitive impairment that would be suggestive of significant brain damage.”

The astronauts completed a series of 10 cognitive tests at five different time points: before their mission, early and late in their flight, and at 10 and 30 days after returning to Earth. While their processing speed, working memory, and attention showed some slowing compared to Earth-based performance, their accuracy remained unchanged.

These changes varied in duration and timing. Attention was only affected early in the mission, while processing speed didn’t return to normal until after the astronauts returned to Earth. The researchers found that the cognitive domains most affected in space were the same ones typically vulnerable to stress on Earth.

Approximately 11.8% of all test scores during flight and post-flight were significantly below the baseline average. However, the study didn’t investigate whether these changes affected astronauts’ ability to perform their duties. “It could be that even in areas with observed declines, astronauts were still able to compensate and effectively complete their tasks,” notes Dev.

This research provides crucial baseline data for future deep space missions to the Moon and Mars, where increased radiation exposure and communication delays could create additional cognitive challenges. Understanding how the brain functions during extended stays in low Earth orbit will help scientists better prepare for these more demanding missions.

Glossary

Processing Speed

How quickly a person can understand and respond to information they receive.

Working Memory

The ability to hold and manipulate information in mind for short periods.

Cognitive Domains

Different aspects of mental function, such as memory, attention, and problem-solving abilities.

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