The basic idea is that we have two ways of learning new information, we have focused and diffused thinking.
Focused thinking works by looking at a problem set and trying real hard to get it. It’s about actively using every ounce of mental force to understand the problem that is in front of us. It’s like seeing a brick wall and reasoning, “It’s too hard to just run through and too tall to climb.”
Diffused learning is just letting your mind wander without a plan. It can deepen your understanding or trigger new creative thoughts. With diffused learning your mind might say, “Hey, why don’t we tie a bunch of balloons together and just float over it?”
Both processes are important to maximise your understanding of a problem you’re facing. To truly optimize your learning, play ping pong between the two: focus, relax, focus, relax, focus, relax,…
The best practice is to first focus all your attention, ideally shutting off any distractions like your phone and other noise. After doing this for a while (a timer can be useful) deliberately stop to focus and let your mind freely wander. This is when the brain connects what you just focused on with other information stored in your memory, which leads to deeper thinking, better retention and allows for creative thoughts to happen.
Painter Salvador Dali was using the ping pong technique. After a round of focused work, Dali sat on his arm chair to think and doze off. In one hand he held a big key and the moment he fell asleep the key dropped. The sound of the key woke him up and he would go back to the canvas to continue his focused work. Steve Jobs broke up his daily thinking routine by going out for long walks.
The ping pong technique can be useful to study for tests. Start with the most difficult problem, once you get stuck, switch to a more simple one. While doing the easier problem, your brain will keep the difficult problem in its working memory. Without conscious thought, your brain will look for connections and try to make sense of the initial, more difficult problem. Once you are done with the easy problem, go back to the difficult one. Maybe it wasn’t as difficult as you thought?