Forgive me if this subject has been discussed before. I know there are many studies regarding this subject, but short of going to see a medical professional , why in the world does my brain become spacey after an intense learning session? Is it that I'm using only one part of my brain, and the rest just goes to sleep? Ive had it happen when driving, or doing other tasks that require simple actions. My mind is lost and into music, I'm guessing. Today I decided to begin two new songs. My brain is weird....
The answer is substrates and vascularization.
Very much like muscles, when you use your brain, it burns up nutrients and other supportive biochemicals, including electrolytes. These are replaced at a rate dependent on the level of blood supply, or vascularization, to the active areas of your brain. You can see enhanced blood flow on CT scans easily, isolated to the parts of your brain that are working the hardest. And like exercising muscles, the deep tissue vascularization, or blood supply, improves with usage. This means you can build up the "supply lines" allowing you to tolerate longer and/or more intense sessions.
Now realize, that when playing a musical instrument, ALL PARTS
OF YOUR BRAIN ARE ACTIVE. So, you will naturally deplete the substrates (supportive biochemicals) more rapidly. Pushing the equation with sugar and caffeine only depletes the substrates more rapidly, risking a crash. When the substrates are used up, and the blood supply can't replenish them fast enough, you get spaced out and need rest. The more intense your focus, the faster you deplete the substrates and cause imbalance of electrolytes.
When this happens, stop playing, stand up, do some calisthenics, maybe eat something healthy. This will get the blood flowing to your brain, reduce consumption of energy and substrates in the brain, and allow the blood supply to rapidly replenish all that good stuff. After extended brain usage, the best rest is a night of high quality sleep.
I hope all this seems like common sense. I mean, I didn't really want to talk about neurotransmitters, mitochondria, waste buildup, and/or the sodium/potassium pump ... I will if I have to...