What is happening during mental rehearsal? Clearly there is learning going on, the question is how much and at what level. There is general agreement that cognitive elements of a skill can be learned in mental rehearsal. Many alternative movements, strategies, and situations can be evaluated. Metal rehearsal even causes some muscular activity and although the signals are too weak to produce the movement required by the action, they may at least produce a program pathway useful in the later real situations.
Now let's consider mental rehearsal as it applies to racing applications. Practice in auto racing presents some peculiar problems. In most other sports, say for instance basketball, one can go to the court and practice a particular skill repeatedly for many repetitions. As it tales on the order of 300 repetitions, to make even a simple task automatic, this type of practice is essential to developing skill. How can you do that in a racecar, especially skills that require traffic? The answer is, of course, you can't. In racing, most of that type of learning is done as a single, isolated situation, occurring during races. Not the ideal time and place to develop skills. These difficulties with real practice make learning very difficult. That is why mental rehearsal actually has an advantage over real practice in racing situations. With mental rehearsal, you can practice the same task or situation repeatedly including those which are too dangerous to practice for real.