Abstract |  What is information for an organism?

The concept of information plays a central role in theories of consciousness, and more generally cognition. Typically, a variable X in the brain is claimed to be informative if it covaries with some other variable Y in the world. This narrow view of information is misleading, because a value cannot be informative by itself: the number 100 only becomes information once I know that it refers to the number of square meters of my apartment, provided I know what square meters and apartments are. The first requirement is that information has a truth value: it can be true or false. In other words, information is propositional: “the winner of the election is Donald Trump” is information, but “Donald Trump” is not information. The second requirement is that information requires an agent with knowledge. I will discuss the implications of these remarks for neuroscientific theories.