I have been a student of the guitar since I was 14. You would think by now I could play like Jimi Hendrix but no surprise I’m not even close (or in the same universe as he). To my defense I was never able to devote tons of time to practice, not that it would have made a big difference, even if practice makes perfect. I guess I fall somewhere in the middle of the ability curve as far as motor learning, nowhere near Jimi Hendrix but not as bad as Richard Nixon (the story goes that he was so bad at motor skills that he accidentally recorded one notorious conversation that ultimately led to his impeachment). If any one of us could be allowed starting at age four in some great experiment to practice eight hours a day could we become another LeBron James? Probably not. Just what goes on when one goes from putting this finger here and another finger here to play an “F” chord on the guitar to playing a series of chords in the span of one second?
One way to think of it is when you first get the notion to learn to play an instrument you likely by a book that explains how to learn to play. You read it cover to cover and, to make things interesting, let’s say you have a photographic memory. So, all the information needed to play is in your brain. But alas, you pick up the guitar and are no better at playing than before you read the book. Why?
The joke “How do you get to Carnegie Hall…you practice!” comes to mind but what happens when you practice? One thing we know for sure is the existence of the speed-accuracy trade-off. For just about any skill the faster one does it the more errors are made. During practice, the brain learns a process called “automatization” where the transition is made from explicit or “declarative” (book) knowledge to implicit or “procedural” (motor) knowledge. Our fingers know something that our brain finds difficult to explicitly explain what it is. At some point in the practice “habits” are formed. Habits are simple steps that get combined into larger units. With three guitar chords (A, D, E) you can play hundreds of songs. The fingerings for A, D and E chords, that at one time took forever to master just one, get combined to play a song. With practice this process of automatization becomes faster and faster. Unfortunately, there is no magic pill that can give us this motor knowledge so we don’t have to practice. On a neural level, both gray matter (neural cell bodies) and white matter (axons and dendrites that connect between neurons) change. The existing neural connections, the synapses, are made more efficient and new dendritic connections may be formed. The mental representations that are first stored in the prefrontal cortex (explicit knowledge) shift to new parts of the brain like the hippocampus, associated with memory and the motor cortex and basal ganglia, associated with muscle control. Imaging studies actually show how the brain changes after practice.
Could the IBM supercomputer Watson ever learn a motor skill? My guess is it is limited to declarative or book knowledge.