The brain icon can be used in a number of ways. It can be used in medical data and literature. For example in an article that specifically talks about brain research or anatomy. It can be used for academic purposes. For example to indicate that a section of a text document is a test, quiz, or a something that needs to be thought about. The brain icon can also be used to indicate that is a brain teaser. It can also be used for fun purposed like in a mobile quiz game, or in a video that talks about the function and usage of an actual brain.