I think this is an unsolved problem. The most interesting thing I saw here is the Recursive Language Models paper.

https://arxiv.org/abs/2512.24601

There's also a great write up here by the author:

https://alexzhang13.github.io/blog/2025/rlm/

This is why in your brain you have trillion threads processing and summarizing sensor data (immutable functions), but a SINGLE thread of “execution” which we call the conscious soul.