Again it all goes down to focus, confidence and mental discilpline. If you know that opponent is saying utter b0ll0cks and just trying to psyche you out, it won't work. Your resistance only grows as you get better at a sport to the point where you don't see the stupidity around you. All you'll ever see is a path and a goal. This is what people like Aryton Senna have achieved, a state of absolute focus.

What I've said before is based on the unfortunate fact that people resort to the most uncivillized means to disrupt others. Like calling names, swearing, etc.

A word on competitive mind games: subtle words and gestures could psyche someone out more effectively than throwing insults around.