Previously, scientists found evidence that a six-month stint aboard the International Space Station (ISS) can temporarily slow an astronaut’s cognitive performance, but shouldn’t create permanent harm. Now, a NASA study published in Frontiers in Physiology examines how processing speed, memory, and attention are affected in space. They concluded that while tasks took longer, accuracy remained intact. The study is the most detailed analysis of its kind, drawing on data from 25 astronauts.

“Living and working in space was not associated with widespread cognitive impairment that would suggest significant brain damage,” said Sheena Dev, a researcher at NASA’s Behavioral Health and Performance Laboratory, who led the project.

This finding counters long-standing concerns about how extended periods in orbit might degrade astronauts’ mental faculties.

Performance in Orbit

Cognitive testing in the study began well before the astronauts launched and continued at regular intervals during and after their missions. The researchers analyzed how quickly and accurately astronauts completed tasks, assessing everything from memory to attention spans. While task completion slowed during missions, the data showed no loss in accuracy.

There were some challenges noticed early in the missions. For example, attention deficits were evident shortly after arrival on the ISS but improved as astronauts adapted to their surroundings. Slower processing speeds, however, persisted until astronauts returned to Earth, often lingering for weeks after re-entry.

The study’s results offer reassurance for long duration space time. Although astronauts work in an environment unlike any on Earth, the mental toll appears manageable. Temporary slowdowns in mental speed didn’t affect overall stability in cognitive performance, nor was there any sign of lasting harm to the brain.

Stress and the Human Mind

Astronauts work under extraordinary pressure. The physical demands of microgravity, exposure to radiation, irregular sleep patterns, and demanding schedules create conditions that few people on Earth will ever experience. Yet the stressors they face share similarities with those in everyday life, particularly in how they affect cognition.

Dev explained that processing speed, working memory, and attention are often the first areas to falter under stress, both on Earth and in space.

“Even on Earth, processing speed, working memory, and attention are cognitive domains that can show temporary changes when an individual is under stress. 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.”

Memory remained consistent throughout the missions. The NASA researchers highlighted this contrast in the paper, noting that not all mental functions are equally vulnerable to stress.

While the research sheds light on cognitive changes during space travel, some questions remain unanswered. The study didn’t investigate why these slowdowns occur or whether they interfere with astronauts’ ability to complete critical tasks. It’s possible that astronauts, trained to operate under intense conditions, developed strategies to compensate for temporary slowdowns.

This limitation leaves room for further exploration. As space missions grow more ambitious, understanding the underlying causes of these cognitive changes will become increasingly important.

With the growing interest in deep-space exploration, these findings carry important implications for missions to the moon, Mars, and beyond. Unlike the ISS, which orbits relatively close to Earth, these missions will expose astronauts to greater levels of radiation and longer communication delays. The data collected from these ISS missions offers a foundation for recognizing and addressing potential cognitive challenges in more extreme environments.

Researchers hope this work will help refine future training and support systems for astronauts. By understanding which cognitive areas are most likely to be affected, space agencies can better prepare crews for the rigors of long-term exploration.