Neuroplasticity: Why are sleep and breaks important for the brain of musicians?

What happens in the brain during different types of breaks? This article examines micro breaks, meso breaks, and macro breaks, much like how we can observe the brain from a microscopic perspective - the neurons and connections - and a macroscopic perspective - brain networks spanning multiple regions. Learn why various types of breaks are crucial at different levels of brain performance for musicians, encompassing a wide range of cognitive skills from basic perceptual and attentional processes to motor learning and musical creativity.

[This article is based on a public lecture I delivered in January 2025 for Reatch at the University of Zurich. A recording is available on YouTube under the playlist "nanoTalks."]

Neuroplasticity in Musicians and Non-Musicians

We humans have approximately 80-100 billion neurons in our brain, roughly as many as stars in the Milky Way! Isn't that fascinating?! And each of these neurons is connected to approximately 7000 other neurons! In total, the human brain has about 600 trillion connections. Children even have almost twice as many, around 1 quadrillion.

It is very interesting that our brain generally does not form new nerve cells after birth, except in two regions: the olfactory nerve cells in the nose and the memory cells in the hippocampus. In general, the reorganization and even pruning, the deletion of connections in the brain, is what makes our brain plastic and helps us learn ("neuroplasticity"). That is the reason why children have more connections – their brain is not yet hierarchically organized like ours. Learning helps the brain mature by deleting unnecessary connections and reorganizing them in the most effective way: regions with specific tasks and networks that organize information processing.

Micro breaks - Perception, Attention and Information Processing

In music, there are not only tones but also breaks between the notes. One is meaningless without the other. Neurons and groups of neurons also need breaks.

You probably know that when a neuron is excited, an electrical signal travels from the cell body through the axon to the end, the dendrites. Here, the electrical signal is transformed into a chemical signal and transmitted to the next nerve cell. In between, there is a phase where it has to relax and return to the electric baseline to be ready to be excited again.

Neurons are, of course, not only connected to one other neuron, but groups of neurons can get tired too. That is the reason why we can only perceive two successive tones or images if the break between them is long enough. Otherwise, one is masked by the other, and we miss it.

And when higher cognitive functions come into play, micro-breaks between notes and between sentences are even more important for the brain of the performer (especially during learning) and even more so for the listeners in the audience. The information traveling electrically from the ear to the higher-order brain regions takes time.

Have you ever watched a film or your favorite series several times? I have, and you will probably agree that every time you notice dialogues or visual details you have not been aware of, while you can recite other parts by heart. Often, those sections follow each other closely! This is because when something catches our attention – for example, if it's very emotional or important to us – we overfocus on it and simultaneously miss other aspects that are occurring right afterward or before. The brain is still busy processing the previous impressions during this time. This phenomenon also occurs very frequently during instrument practice: important, difficult, or erroneous passages in musical pieces draw so much attention that technical or musical imperfections or even mistakes occurring shortly afterward (or sometimes just before) are masked, i.e., concealed, and not noticed by us.

(See also: Attention - the underestimated brain function of playing music)

Why is that so? If I play a simple sound 100-1000 times and record electrical brain activity from the scalp using electroencephalography (EEG) and average over all of them, we get a characteristic wave (see image on the left). The peaks and dips correspond to successive processing stages on the way from the ear to the cortex where conscious perception and reasoning happen. The very early waves from 6 ms after the sound are related to activity in the inner ear itself and the auditory nerve. They reflect peripheral sensory processing. The following waves are generated by basic sound processing in the brainstem, unconscious parts of the brain. Only after 100-200 ms does the information reach the cortex, where sound is consciously processed. Activation in the primary auditory cortex (blue) indicates: you have heard the sound. Not less, not more.

Later waves, occurring between approximately 200 ms and 1 second after the sound, reflect higher-order or cognitive analysis of the sound in secondary auditory fields in the brain. For example, conscious comparison with the previous note (Is it right or wrong? Does it reflect my expectations from a melodic, harmonic, and rhythmic point of view, etc.)

(Grafik modifiziert nach Hillyard & Kutas,1983)

Ernest Hemingway, a writer of short stories, was a master of the silence between the words. He knew what needs to be said and what information is transmitted indirectly between the lines by the reasoning and assumptions of the reader. With music it is similar. Sometimes silence is more powerful then sound and one if each cannot go without the other. Breaks and silence give the brain time to cognitively process the information and associate it to personal experiences. We can then “understand” it. 

Meso breaks - Motor Learning and Consolidation of Knowledge

This is my cat, Smilla. She is 2 years old and sleeps approximately 15-18h a day, more in winter. That’s completely normal for a cat of her age. Just recently I have realized: newborns sleep roughly as much as adult cats! Did you know that?

As we grow up, the need for sleep gradually decreases until, as adults, we sleep an average of 7-8 hours a day—or at least we should. Sleep is necessary for physical restoration and the immune system. Additionally, it is particularly crucial for the plastic changes in the brain associated with learning and processing experiences. That's probably the main reason why children need more sleep.

Sleep, as well as breaks between practice sessions, is important for learning processes.

Let's look at that from a musical perspective:

When I was a student, I sometimes played piano trio with a violinist and a cellist, both of whom were studying music at that time. I was just an amateur pianist. We met to sight-read some trios for fun. One key aspect I remember from those sessions is that after around 15-20 minutes, the cellist would stand up and say he needed to sleep! He would then find a spot, sometimes in the same room, and take a nap! At that time, we found it a bit ridiculous. Later, I found out that a study showed the best violinists were those who took a nap in the early afternoon between practice sessions (Ericsson et al., 1993)! Of course, the cellist didn't know that, and he ultimately didn't pursue a career in music. Still, I was reminded of that experience while reading the paper. However, it's important to note that this study, now almost 30 years old, has some methodological weaknesses and only shows a correlation. From it, we cannot conclude that sleeping makes musicians better; it could also be that good musicians need more sleep or that this correlation was found for other reasons.

But nowadays, we have plenty of evidence from neuroscience showing how important sleep is for learning:

Humans sleep in different sleep phases, and we can measure this from the outside by recording brain activity. There are phases of deep and light sleep (S1 to S4) and REM sleep.

(from Simor et al., 2020)

Deep sleep mainly occurs at the beginning of the night and has been shown to be particularly important for storing facts and knowledge in long-term memory (Hippocampus)! For example, facts like "who was the composer of 'Für Elise'?" or "the piece starts with an 'E'."

Until the end of the night, there are more phases of light sleep, and especially REM sleep. The REM sleep phase ("Rapid Eye Movements") is named after the rapid movement of the eyes during this phase. In this phase, we often vividly dream, and it is particularly important for motor learning.

When researchers want to investigate motor learning from a neuroscience perspective, a typical task is a so-called "Tapping" experiment. The fingers are numbered like the fingerings of pianists, and participants have to learn to tap certain sequences—either only one hand involved in the sequence or both hands.

Several research groups have used this tapping task, and here are the three key findings:

1. Musicians are better at the task—not surprisingly, as motor learning is what they have been training for years (Tucker et al., 2016).

2. People who were allowed to sleep normally improved more overnight than those deprived of the REM sleep phase (the researchers essentially woke them up when they were about to enter the REM phase) (Kuriyama et al., 2004).

3. The "problem points" of the sequences improved the most during sleep (Kuriyama et al., 2004).
   

Other studies have also explicitly investigated the smoothness of pianist scales and found a similar effect (Simmons et al., 2006).

So, motor learning seems to benefit from REM sleep. One neuroscience hypothesis is that during sleep, unnecessary temporary connections between neurons are cut again to make movements more efficient. Longer breaks between practice sessions can have a similar effect, but only if the "wrong" patterns are not ingrained too deeply by repeated practice.

So, for fact learning, we need the deep sleep phases at the beginning of the night, and for motor learning, we especially need a healthy, long sleep with enough REM phases at the end.

(See also: Sleep - or why it is indispensable for musical success and Musical Memory - remembering faster with the seahorse)

Macro breaks

My favorite island is Juist. It is a 17-20 km long and only 1 km wide island in the national park region of the German North Sea. From many spots, you can see the sea on both sides. There is not much to do: walking along the beach, swimming in the sea, there are no cars, horses deliver the mail, and nature life is protected. There is lots of time for mind-wandering.

Such breaks, where the mind can wander around, and we have no tasks are important for creativity. To understand this, we need to have a look at the macro scale: brain networks.

Brain networks connect regions of the brain that work together for a certain purpose. One of these networks is the Default Mode Network (DMN), and it plays an important role in creativity. This network is usually active when we do not engage in specific tasks and just let our mind wander around. It is, for example, also active during meditation, reflecting about self and others, emotional reasoning, and mental simulation.

Several studies like the one by Bashwiner and colleagues (2016) have found that the DMN plays a crucial role in creativity of any type. Here, the researchers found that musically creative people (e.g., those who regularly improvise or compose) had relatively larger regions in areas of the brain that belong to the DMN.

The researchers found two other types of networks that are important for creativity:

1. Domain-specific networks developed over years of practice: motor and sensory regions in musicians.

2. An emotional network: that is perhaps relevant to create the drive and motivation to create and fuel the art with emotions.
   

So brain networks reflect different states of the mind between which we can alternate. For creativity, we need the alternation between domain-specific networks of the required skills and knowledge and the domain-general status of mind-wandering or emotional processing. We cannot have this in the hustle of daily life, in task mode, or while being tensely focused on a goal. To come into this state, we need to reduce judgmental ("right," "wrong") and cognitively controlled behavior and let perception, imagination, and associations flow. It is a state of relaxed, broad, defocused ("observing") attention as opposed to narrow, task-focused attention (concentrated, sometimes forced "wanting"). It is also especially helpful to practice a state of relaxed, non-judgmental attention during music practicing to maximize success and minimize vulnerability to performance slips, tensions, and anxieties.

We don't have to go on vacation to activate the DMN. Islands of mind-wandering can be part of our daily life, for example, on the train, in the bathtub, or while practicing meditation or engaging in non-judgmental practicing. It's not a coincidence that the ancient Greek term "Heureka" is attributed to the mathematician Archimedes. He is said to have run naked through the streets of Syracuse shouting "Heureka" because he had just made a discovery in the bathtub. The solution to the problem revealed itself to him during the state of mind-wandering!

So do it like Archimedes or even like Isaac Newton: Do your practice and work, but also take time to sit under an apple tree and let the apple and insight come down on you.

I tried this in Cambridge 10 years ago under the symbolic apple tree in front of Trinity College, where Newton studied. I waited for some minutes, but unfortunately, no apple fell onto my head. :-) Similarly, we cannot force apples to fall on our heads, and we cannot force mind-wandering to be creatively productive. However, we can deliberately create optimal environments and life habits to enter this state as often as possible as an alternation to task-specific musical learning. And make sure to have enough "breathing" breaks for perception during and in between practice sessions and enough sleep for the consolidation of what you have learned.

What are your "islands" of mind-wandering?

---

Sources and further reading

• Bashwiner, D. M., Wertz, C. J., Flores, R. A., & Jung, R. E. (2016). Musical creativity “revealed” in brain structure: interplay between motor, default mode and limbic networks. Scientific reports, 6(1), 20482.

• Ericsson, K. A., Krampe, R. T., & Tesch-Römer, C. (1993). The role of deliberate practice in theacquisition of expert performance. Psychological Review, 100(3), 363–406.

• Iglowstein, I., Jenni, O. G., Molinari, L., & Largo, R. H. (2003). Sleep duration from infancy to adolescence: reference values and generational trends. Pediatrics, 111(2), 302-307.

• Kuriyama, K., Stickgold, R., & Walker, M. P. (2004). Sleep-dependent learning and motor-skill complexity. Learning & memory, 11(6), 705-713.

• Tucker, M. A., Nguyen, N., & Stickgold, R. (2016). Experience playing a musical instrument and overnight sleep enhance performance on a sequential typing task. PLoS One, 11(7), e0159608.

• Simmons, A. L., & Duke, R. A. (2006). Effects of sleep on performance of a keyboard melody. Journal of Research in Music Education, 54(3), 257-269.

• Simor, P., van der Wijk, G., Nobili, L., & Peigneux, P. (2020). The microstructure of REM sleep: Why phasic and tonic?. Sleep medicine reviews, 52, 101305.