Friday, 1 December 2017

Music Practice Changes Your Brain

How does a life with or without music practice change your brain? Photo by T. Gaertner

When I have kids who are struggling with their piano pieces, I try to encourage them by acknowledging that playing the piano is hard. In fact, by learning how to play music, they are actually changing the structure of their brain.

But how much am I exaggerating here? How much does musical training really change your brain?

There’s some pretty good evidence to support the fact that musical training causes people to have larger auditory cortex, a larger hand area in the motor part of their cortex, and better connections between these two areas and between the two sides of the brain. This research has generally been done two different ways: a) by comparing the brains of musicians to those of non-musicians and b) by giving music lessons to children and seeing how their brain structure changes.

Both of these types of research have the same problem: we can’t tell what differences are caused by practice and what are caused by genetics. Perhaps people who have brains that grow larger auditory cortex (for example) are the ones who have a natural talent for music, and so they continue with lessons and become musicians. In other words, maybe it was the brain structure that caused the person to be a musician, not the other way around. Maybe the kids who stick with music lessons are the ones whose brains are genetically predisposed to being “musical”.

What would be really useful is some magical way of taking a single person and seeing what their brain would look like with and without a lifetime of musical practice.

A recently-published study has managed to do the next best thing. The researchers, Örjan de Manzano and Fredrik Ullén, at the Karolinska Institute in Sweden, studied 9 identical twin pairs in which one twin studied piano and the other did not. In each pair, both twins started music study at the same time but one dropped out of lessons quite early while the other continued with piano lessons. On average, the piano-studying twin had played the piano for over 4000 hours more than the twin who quit piano, and the playing twin was still an active amateur pianist.

The researchers looked to see what differences in brain structure were found between the practicing and non-practicing twins, assuming that if the piano-playing twin hadn’t practiced, their brain would look like their twin’s (which is a reasonable assumption, based on other twin studies). Basically, the non-practicing twin acted as a control for the practicing twin.

What they found confirmed some of what had been found in previous studies: musical training leads to a thicker cerebral cortex in auditory and motor areas on the left side of the brain and a greater volume of grey matter in parts of the cerebellum, which plays a role in motor control. Musical training also increases the organization of white matter in the auditory and motor parts of the cortex on both sides of the brain and in the corpus callosum, which connects the two hemispheres.

These changes in brain structure are found in the parts of the brain most used in piano practice. When we practice, we’re connecting auditory information with motor control, linking up the movements that we need to make in order to produce audible musical sounds. In the brains of musicians, the auditory cortex, the motor cortex, and the fibre bundles that connect these regions are bigger and better organized. Also, the corpus callosum, which plays a role in bimanual co-ordination, has more organized structure. These differences in brain structure between piano-playing and non-playing twins are clearly not due to genetic differences, so they must be due to differences in life experience. In other words, hours and hours of music practice have altered the structure of the playing twins’ brains.

This result does not mean that genetics has no role in musical ability. Other research from the same lab at the Karolinska Institute has suggested that amount of practice is less important to musical expertise than genetic factors. Our genetics not only influence the fluidity of our motor control and our ability to discriminate pitches and keep a beat, but also shape how much we’re willing to practice, our ability to focus, and our emotional and motivational responses to music. But, as this twin study clearly reveals, our day-to-day experiences with music also play an important role. The question is not whether musical ability is shaped by nature or nurture; as with almost everything, both play a role. The interesting question is how nature and nurture interact to mold our abilities.

So yes, music practice really is changing your brain. Of course, music study is not necessarily unique in this regard. Anything you spend a lot of time doing is going to change your brain. For example, expert basketball players surely have different brains too. But not all skills lead to long-term, large changes in brain structure. In fact, there is a theory that learning a new skill causes brain growth at first, but then as the skill is solidified, brain structure is renormalized and returns to its original size. The fact that this doesn’t seem to happen with musical training suggests that playing an instrument depends on a difficult set of skills requiring specialization of a number of parts of the brain. Mastering these skills does not come without effort.

As for my struggling students: Knowing that this is true doesn’t make it less work, but perhaps it can be reassuring, and motivate them to keep growing the auditory-motor parts of their brains, synapse by synapse.


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