To answer the question, I would say, sure. I was listening to this episode of Radiolab, and I disagree with the “voice” in your head.
Think back to before a common language was developed, gestures or facial expressions were probably developed to help the communication. The dilemma is, if you didn’t think, how could you develop a language? For this philosophy to work, you would have to already have a language before we could think. But probably you would have to think of the gestures that communicated an idea, in an abstract way, back in the days. So if we never “thought” of developing sounds that resembles a language, then we would never “think” so this philosophy does not work. Sorry, Dr. Charles Fernyhough, that theory just does not work. This story proves it!
I think you just think differently if you don’t have a language because you still have memory, you probably have a better memory since you have to be creative in communication.