here's a parragraph in which I replaced "brain" with "scientist" and mouth with "experimental data"

The point of this is to form a hypothesis. If the scientist and the experimental data say the same thing, then the scientist will think it has a hypothesis that is correct. But if the experimental data and the scientist say different things, then the scientist will think it has a hypothesis that is wrong. The scientist will think the experimental data is right, and it will change its hypothesis.