The theory of overlearning is complex, the implementation of overlearning is very simple. You learn something till you get nearly 100% score, take some rest and then you learn it some more to get nearly 100% score the next time you need to use your skill. In other words, if you simply learn something and have a test the next day, you will forget a bit and your score will not be perfect. If you overlearn, you will not forget and have the perfect results.
How does it work? Forgetting curve ensures we learn as long as we live. Even if we get 100% performance today, it will degrade over time no matter what we do. The underlying phenomenon is degradation of neural connections over time. If the neural connections are stronger than they actually need to be, even after degradation you will get sufficiently strong neural connections. So by practicing more than you need, you ensure your neural connections are strong enough.
In a highly competitive environment, even a small performance advantage counts, so sportsmen and musicians practice overlearning regularly.
A good usage of overlearning is boosting short-term performance results. The effect of overlearning in not long-term: it will get you through an exam, but will be negligible 10 years afterward. Deep intuition and understanding will always last longer than the results of specific practice.
We can continue practicing even more, and then we have an additional effect. The activity we practice becomes automatic and we free up our brain to do other tasks. For example, when learning foreign languages there is an immersion technique. We read, watch and talk the language we want to know till we start having dreams in that language. At that point, the language becomes truly automatic and we can use it effortlessly. Even then we will probably forget a large part of what we learned and will need to relearn if we do not use the language for more than 10 years.
There are examples of people who routinely overlearn the same skillset for decades since they were very young. Such overlearning can actually change the way your brain and body are formed, and various areas of the brain that normally deal with other tasks will start to address the required activity. With the introduction of fMRI came stories about chess players who use the brain’s face recognition areas to analyze the chess board. The effect is somewhat similar to synesthesia in musicians, where the brain areas that typically deal with vision also start dealing with music.
So what is the right learning strategy? It is always beneficial to have a deep understanding and intuition since they will last for decades. At the beginning the more you practice the better you perform until you reach a plateau. If you practice a bit more, you will keep your shape a bit longer. However, if you practice significantly more, the practice will become your second nature.
When Anna just started to teach, she used to bring people to the top reading speeds and watch them degrade to regular speeds over a year. By putting emphasis on continued practice for years after finishing the course, the degradation was replaced by gradual improvement. If you study yourself, do remember: the end of the course is just the beginning of your practice. Continue reading and you will improve, stop reading and your skills will degrade.
If you need to perform competitively simply learning is not enough, you need to overlearn. Continuously overlearning something will make it your second nature. Choose wisely what you want to learn and forget and what you want to practice for decades.