It's not really a valid question, in my experience--I lose intelligence when I'm depressed, and I suspect that worrying about losing aspects of intelligence can be a depression trigger.

One odd thought: I lose nouns in spoken conversation, but not typed (email, LJ, Usenet, IM). You might want to experiment and see if they're still there for you, using that retrieval mechanism. It doesn't help that much when I'm talking to someone in person or on the phone--especially if I don't have a keyboard handy--but it's reassuring to know that they're still there, and that I can get at them.