Why is Playing Music a Challenging Mental Task?

Do you love music? Do you play any musical instruments? Many of us see music playing as an enjoyable leisure activity. However, have you ever wondered whether music playing is a challenging cognitive task?

A cognitive task refers to an activity that involves mental processes, such as reading text or playing music. When we play music, we handle many mental processes at once. For example, we read musical scores, listen to the sound produced, count the beats, and coordinate our eyes, hands, and mouths. In addition, we feel emotions from music, and we can make the audience feel emotions when we play. We also coordinate with other players when we play music in groups. We appreciate the beauty of music and connect it to our unique personal experiences. It may be hard to understand how the brain handles complex musical tasks before knowing more about this organ. So, let us look into the brain and see how it handles other cognitive tasks.

The Two Sides of the Brain

The human brain is a complex organ consisting of two halves, called the left and right hemispheres. The two hemispheres have their own strengths in cognitive tasks. For example, the left hemisphere is better than the right hemisphere in processing English words. In contrast, the right hemisphere is better than the left hemisphere in processing faces. When one hemisphere has a processing advantage over the other in a cognitive task, this is called hemispheric lateralization. Thus, English word processing tends to be left-lateralized, while face processing tends to be right-lateralized [1].

Do any cognitive tasks involve both hemispheres? The quick answer is yes. Some studies have shown that both hemispheres are involved in the processing of Chinese characters [2], although other studies indicate that the right hemisphere is better at it.

Interestingly, our brains may change based on what we do. This concept is called brain plasticity. Brain plasticity could show up as a change in hemispheric lateralization. One study showed that musicians used both hemispheres when listening to music, while non-musicians tended to be more right-lateralized when they listened [3]. So, that study highlighted that hemispheric lateralization is related to the level of expertise—how good a person is at doing a particular cognitive task. In our study, we wanted to explore further whether and how music training might change the brain, especially in terms of hemispheric lateralization.

Music and the Brains of Musicians, Music Learners, and Non-Musicians

In our study, we recruited 38 musicians, 26 music learners, and 33 non-musicians, aged 18–33 (with an average age of 20–21) from Hong Kong, China. Despite their different music training backgrounds, participants had similar language and educational backgrounds, left- or right-handedness, and memory.

Musicians were well-trained music players who played the piano and/or other Western instruments. They had attained at least grade 8 or above in the Associated Board of the Royal Schools of Music (ABRSM) graded music examinations (or equivalent). On average, they started music learning at the age of 6 and had 14 years of experience playing music.

Music learners were music players who also played piano and/or other Western instruments. They had attained at least grades 2–5 in the ABRSM graded music examinations (or equivalent). On average, they started music learning at the age of 8 and had 8 years of experience playing music.

Non-musicians did not play music. They did not receive any formal music training in Western instruments and did not read music scores.

All participants completed a set of matching tasks with musical elements, and they answered a questionnaire called the Goldsmiths Musical Sophistication Index [4] to measure their general musical skills.

We designed a set of matching tasks with four different musical elements, including single notes, chords, rhythms, and musical expressions, in this study. The matching tasks were designed based on the relationship between the brain’s left and right hemispheres (LH and RH, respectively) and the two visual fields: the left visual field (LVF) and the right visual field (RVF). Visual fields are the areas that you see either on the left or the right without moving the eyes. What you see in the left visual field is projected more directly to the brain’s right hemisphere, while what you see in the right visual field is projected more directly to the left hemisphere (Figure 1) [5]. In the matching tasks, we presented musical elements to our participants in both the LVF and RVF, to explore if musicians, music learners, and non-musicians have different hemispheric lateralization effects in music reading based on their different levels of musical expertise.

In each trial, two musical elements were shown briefly in the LVF and the RVF on a computer screen. The first target musical element was the musical element that was indicated by an arrow, either pointing to the left (e.g., ←) or to the right (e.g., →). The second target musical element was then presented at the center of the screen. Participants judged whether the first and second target musical elements were the same by pressing a response box. For example, a note E was shown in the LVF, while a note D was shown in the RVF, with a right arrow in between. It indicates that the first target musical element was the note that the right arrow was pointing to, which was a note D. Then, the second target musical element would be presented at the center of the screen, for example, a note D. Since both the first and second target musical elements were both note D, participants pressed the “same” button on a response box to indicate their answer.

We used an eye-tracker to monitor whether the participants were looking at the center of the screen before each trial. An eye-tracker is a device that is placed at the bottom of the screen and traces where the participant’s eyes move while they read the screen. Eye-tracking helps us measure hemispheric lateralization effects objectively and accurately. It ensured participants were looking at the center of the screen when stimuli were shown in the LVF and the RVF simultaneously and projected to the RH and LH, respectively.

Music Training Changes How the Brain Reads Music

Our findings showed that music training changes how the brain reads music. Musicians had a similar performance in judging whether the two target musical elements were the same, no matter the first target musical element was presented in the LVF or the RVF. This suggests that musicians used both hemispheres to read music (Figure 2A). The ability to actively process musical elements in both hemispheres could be related to musicians’ strong capacity for music reading.

In contrast, music learners performed better when the first target musical element was presented in the RVF/LH rather than the LVF/RH. This suggests music learners were more left-lateralized in music reading (Figure 2B). Since music learners may have limited capacity in music reading, they may tend to focus on details (e.g., lines/spaces on musical scores), which tends to be a left-lateralized strategy.

Finally, non-musicians performed better when the first target musical element was presented in the LVF/RH rather than the RVF/LH. This suggests non-musicians were more right-lateralized in music reading (Figure 2C). With very limited or no experience in music reading, non-musicians may rely on information such as shapes to complete the task, which tends to be a right-lateralized strategy.

In addition, in the Goldsmiths Musical Sophistication Index, music training was the factor that relates to how we use one side of the brain more than the other when reading music (Figure 3). No similar findings were observed in other factors measured, such as active engagement, perceptual abilities, singing abilities, emotions, and general musical sophistication. Our finding shows that the more music training an individual has, the stronger the tendency to use the left side of the brain for music reading. This left-lateralized tendency may be related to the complexity of music training, which involves extensive training in multiple skills, such as music listening, music perception, music reading, and eye-hand(-mouth) coordination.

Take-Home Messages

To conclude, this study showed that music training changes how the brain reads music across different levels of musical expertise. We found that musicians used both hemispheres to read music. Music learners were more left-lateralized in music reading, while non-musicians were more right-lateralized. Given its complexity, music training was the musical component that relates to how we use one side of the brain more than the other in music reading, as shown in the Goldsmiths Musical Sophistication Index. This study gives us a more comprehensive picture of how the brain changes in response to what we do and how good we are at doing that activity. We hope that this article will help you see music training as more than just a leisure activity—it has value as a complex mental task that can reveal the brain’s potential.

Glossary

Cognitive Task: ↑ An activity that involves mental processes, which are the processes that happen in the mind. Common examples are reading text and playing music, etc.

Hemispheres: ↑ The two halves of the human brain. The left half is called the left hemisphere, while the right half is called the right hemisphere.

Hemispheric Lateralization: ↑ The processing advantage of one hemisphere over the other in cognitive tasks. If processing relies on the left hemisphere, it is called left-lateralized; reliance on the right is called right-lateralized.

Brain Plasticity: ↑ The potential of the brain to change due to experiences, or to compensate for lost functions due to injuries.

Visual Field: ↑ The areas that you see without moving the eyes. The area on the left is called the left visual field, while the right area is called the right visual field.

Eye-tracker: ↑ A digital device that measures how a person’s eyes move. This device helps researchers to understand human minds through studying a person’s eye movements.

Conflict of Interest

The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgments

The work described in this paper was fully supported by the Hong Kong Metropolitan University Research Grant [HKMU R&D Fund for Individual Academic Unit (A&SS); No. 2021/22 A&SS]. We also thank Miss Cloris Tse for helping with the stimuli creation and data collection in the original study.

AI Tool Statement

The author(s) declared that Generative AI was not used in the creation of this manuscript.

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