Yeah, you can prove pretty much anything with a pubmed link. Do dead salmon "think?" fMRI says maybe!

https://pmc.ncbi.nlm.nih.gov/articles/PMC2799957/

The resources that the brain is using to think -- whatever resources those are -- are language-based. Otherwise there would be no way to communicate with the test subjects. "Language" doesn't just imply written and spoken text, as these researchers seem to assume.