If you grow up with absolutely no exposure to language, how do you think?

Seems like a simple enough question, at first glance, but it’s really a difficult theoretical issue to address.

Think about it… nearly all of our thoughts that aren’t strictly image-based are automatically formed and analyzed using our own language-based “internal voice.”

So if someone was left on an island at birth and grew up with zero exposure to any type of language, how would their thoughts be organized and interpreted? Could they even functionally think at all? How would their memories be formed and recalled?