Since perceptions of time and space are believed to share the same neural processes, and research on depth perception in weightlessness has shown that astronauts often underestimate distance, scientists speculate that for astronauts time also flies in space.
The Time experiment on the International Space Station investigates the claim that time subjectively speeds up in microgravity.
Astronauts gauge how long a visual target appears on a laptop screen and their reaction times to these prompts recorded to process speed and attention.
Scientists are not only collecting data on the neurological mechanisms at work here. The relativity of time, after all, implies that it is all in your head. As much as we can objectively measure and plot time, how individual humans perceive it is not just neurological but also psychological.