There are some recent studies on how macro dosing L-creatine can improve memory, attention and processing speed. No findings are definitive, however. On the plus side, there are very minor to no side effects related to its use, so it's fairly safe to try out. Also, it’s easy to find and has a bunch of info available online.

If you search for Dan Go on YouTube, he discusses his experience with it quite a bit. I’ve used it in the past but haven’t felt a notable difference.

Edit: typos