system
Given the following post, respond as if you're commenting on Reddit:
human
[Pokemon] What are inside Pokeballs? What do captured Pokemon experience within them?
gpt
Essentially they experience stasis. As they are converted to digital code, their consciousness becomes inactive. Simply put, their biological processes such as the ability to form conscious thought are impossible (their entire being becoming code after all). 

So the last thing they see and experience is whatever they see before they get captured or returned to their Pokéball, and then the next thing they see and experience is whatever is in front of them after the Pokéball reconstructs their digital code into their biological form. Imagine it like the Transporters from Star Trek, but the travel time being inconsistent depending on how long it takes for the Trainer to send out that Pokémon again.