In the good old days of elementary school, I was absolutely fascinated by the trip taken into the human body by Mrs. Frizzle and her class on “The Magic School Bus”. How amazingly orchestrated our bodies have to be, and at the center of it all lies the command and integration center- the brain. What do you think Mrs. Frizzle would have found had her class taken a trip into the brain of a musician? Interestingly, she may have been in for surprisingly different geography.
At the surface of the human brain lies the outermost layer of neural tissue called the cerebral cortex. While only around 3mm thick, this area contains most all of the gray matter in the brain- gray matter being the actual cell bodies (and any unmyelinated fibers). The cerebral cortex has multiple layers that are folded into grooves called sulci in order to maximize surface area. This complex area has been mapped out by scientists and includes specific areas for motor control and various types of sensory perception and also includes pre-frontal areas that are key in critical thinking, decision making and problem solving
In any human, the magic school bus would have driven over the classic noodle-ish landscape, but in a musician, the landscape is more expansive, and the areas devoted to motor skills and sensation can be wildly redistributed! Musicians have been shown to have more gray matter than non-musicians. Studies have confirmed not only a greater number of neuronal cell bodies, but even an increase in size in cell bodies, especially in auditory, motor and visual-spatial cortex. Years of practicing and playing an instrument actually changes the number, size and distribution of neurons in the cortex. Music practice even modifies the number of synapses (connections) and the types and strengths of synapses between a musician’s neurons!
Now, imagine the bus driving across a United States map that has been drawn on the brain surface. Each state represents a specific body part. A violinist will have a very large “state” area devoted to their left hand as compared to their right, while a pianist may use the same area in a finer balance between their two hands. It’s as though the violinist has started out with the usual Colorado border for their left hand but over time slowly invaded Utah, creating one super-sized Colorado and leaving a mere fragment of Utah for their right hand. Each finger of the violinist’s left hand may have its own county, while the right has less definite county boundaries. The fine motor skills required of the individual fingers in either musician will likely have allowed the map area for each finger to spill over and recruit neurons from adjacent areas…borrowing from the motor areas of less utilized body parts, creating an extremely unique map.
This borrowing and rearrangement occurs not only in areas associated with muscle control, but also in brain areas concerned with the sensations of touch, hearing and vision. Especially notable is the fact that musicians have even been known to use their visual cortex to assist in verbal word recall, typically a task performed by auditory areas of the brain! This anomaly may have developed in response to musicians utilizing integration of their visual and auditory cortices to memorize and recall pieces of music as they play. The magic school bus might have hit quite a speed bump here!
The modifications that take place in the cerebral cortex are quite extraordinary and represent a process called neural plasticity. Studies have found such plasticity to be quite long term in some cases, especially in musicians who have studied from a young age. Duration of practice may also factor into this equation. However, other studies have shown rapid reversal can occur too. So, it's always best to keep on practicing! Next time we’ll take a short drive down the road to the pre-frontal cortex and areas of fine information processing. Fasten your seatbelt Mrs. Frizzle!