Inner Speech

Most people use language not only to speak to one another—aloud or quietly—but also in complete silence, solely in their minds. We do this to remember shopping lists, to predict what the person we’re talking to might say next, or even when thinking about complicated problems. What brain processes underpin this kind of “linguistic” thinking? And do all people do this in the same way?

People differ in how they experience linguistic thinking, and these differences also have implications for certain thought processes. We want to investigate exactly how inner speech is processed in the brain, what we use it for, and how we came to have it in the first place. Do babies already have inner speech? How has it evolved over time, and how might it change through conversation with language models?