The available data suggest that gaining expertise in any domain requires at least four hours of training per day for approximately 10 years. Remarkably, there is also compelling evidence that motor imagery—that is, visualizing certain movements in the mind’s eye—can also enhance the learning and execution of certain skills. Thus, imagined movements appear to be equivalent to those that are actually performed, and merely “going through the motions” in one’s mind can lead to the same kind of plastic changes in the brain.
