I'm worried Artificial Intelligence could make us stupid

Once upon a time if I wanted to find my way to somewhere unfamiliar, I would have pulled out a map and plotted my route. These days I just put the destination into my smartphone and let it make all the decisions. Is this a simple, practical thing to do or, by relying on increasingly smarter phones, are we allowing them to make us, day by day, a little bit dumber? I've spent the last few days at an international conference on artificial intelligence pondering just this question. We were discussing, among other things, the effect that the rise of machine intelligence is having on our brains.