"At one point or another, whether during a showing of The Matrix or sitting in a freshman existentialism seminar, we've all pondered life's eternal questions: Why do we dream? Are we just living in a computer simulation? Do you see the same blue that I see?
Usually we come to the same conclusion: We have no idea, and we never will.
But it turns out that brain scientists like to get just as meta as we do, and unlike us, they have the tools to answer these questions."