Jeff Cooper spoke obliquely about some of these training problems in the chapter Principle Five: Coolness, in Principles of Personal Defense. He points out that cops who obviously have the marksmanship skills necessary to pass qualification tests still frequently miss their targets, "due to his lack of concentration upon his marksmanship --- the loss of his cool."
Cooper opines that various athletic sports are good training for situations in which you know that if you can keep cool, that you must, keep cool, that you probably will keep cool. He recommends various sports, but said that the hunting of medium and big game is the best of them all for training oneself to remain calm under pressure of making split-second decisions requiring precise reactions to the circumstances presented. Also worth reading, on the instantaneous decision-making process, is Malcom Gladwell's Blink, (nothing to do with gunfighting, everything to do with why and how our brains can make instant, usually correct responses to incoming information...)
Anyone fortunate enough to have access to a FATS (Fire Arms Training System), as referenced in the article, ought to use it as frequently as time and budget permits --- it provides the best shoot/no-shoot training system I've ever experienced.