Besides that, it exposes a lot of constraint on cognition in general. Linguistics at MIT is dominated by the Chomsky school. You may or may not find this to your liking. Check out George Lakoff's recent book Women, Fire, and Dangerous Things as an example of an alternative research program. Knowing EE is also useful when it comes time to build a custom chip or debug the power supply on your Lisp machine.
Physics can be a powerful influence for people interested in perception and robotics.
Philosophy is the hidden framework in which all AI is done. Most work in AI takes implicit philosophical positions without knowing it. It's better to know what your positions are. Learning philosophy also teaches you to make and follow certain sorts of arguments that are used in a lot of AI papers. Philosophy can be divided up along at least two orthogonal axes.