Professional athletes may take the time to invest in goggles or other devices to help train their mental abilities (and I've no doubt they can be trained), but most high school or college athletes would probably not have the time/money/interest to make that investment. But I still think there are ways to incorporate visualization, mental game preparation, and positive self-talk into their sports. Thoughts become things. If you build good mental habits, you can improve your performance.
I tend to read info that feels practical to me, like this article on visualization:
The Power of Visualization. And this article about mental preparation for the batter (my son plays baseball):
Hitter’s Checklist: Consistent Hitting Through Preparation. The idea of putting the right thoughts in the right order to create a positive effect on performance makes a lot of sense to me.
If you
search the NSCA journals online you can find a lot more information on sports psychology and mental preparation for sports.