I'm on a Macbook Air, running El Capitan (10.11.6), and I'm not very knowledgeable about computers. I have a quick question about the Finder/Spotlight search.

So, as a grad student, I have tons and tons of PDFs on my computer. A lot of times, it's helpful for me to perform a keyword search to look for references (I often forget that I've downloaded relevant files), and Finder has done a perfectly serviceable job searching through file contents and through file names up until about the last week. Suddenly, about a week ago, I realized that Finder was only indexing search results that had the keyword in the file *name*. 

I've tried poking around in search preferences to no avail, and I've looked for forums addressing this problem online. I have seen plenty of people who want to search file-names and *can't* (i.e., they can only search file contents), but I have not seen my problem anywhere.

Does anyone have any suggestions as to what might be going on here and how I could fix it? I have even tried re-indexing the search results as suggested elsewhere on StackExchange as a general tip for people with faulty Finder searches, but that didn't do anything for me.

Thanks so much for your replies in advance!