November 14th, 2023
Written by: Lisa Wooldridge
As the joke goes, when a tourist gets lost in New York City on the way to a concert, he stops a musician walking by and asks how to get to Carnegie Hall. Instead of responding with directions, the weary musician simply replies, “practice, practice, practice!” How does practice make a musician better? Can anyone who nurtures their interest enough, become a musician? And is it all there is to it – or are there any natural features that some musical folks are born with? A new study suggests that both nature – features you’re born with – and nurture – musical training and practice – work together to influence musical interest and aptitude.
Because many adult musicians began training as young children, it is often difficult to distinguish between nature and nurture when studying the brains of adults. To solve this problem, a team of researchers in Germany and Austria collaborated on a longitudinal study that followed children through adolescence and into early adulthood1. In a longitudinal study, measurements are collected repeatedly at several different times to better understand how conditions evolves over time. The researchers started following children when they were 7-8 years old, collecting data on them every 2-3 years until they were 17-19 years old – five time points in total (Figure 1).
At each time point, they collected four different types of data. First, they determined how much formal musical training each child had up to that point in their life. They then divided the children into a “musician” group – those children that had the most musical experience – and a “nonmusician” group – with little or no experience. Second, they had the children complete musical aptitude tests, which screened them for skills such as identifying differences in volume, pitch, or length of two similar tones. As you might expect, there was a strong correlation between musical experience and performance on these aptitude tests – children with more experience tended to perform better. Third, they looked at the structure of the auditory cortex as the children grew and accumulated more musical experience. The auditory cortex is a part of the brain that processes what we hear and fits it in with information from our other senses, so it plays an important role in processing music. Finally, they looked at how each child’s auditory cortex responded to sound.
Does musical training affect the structure of the auditory cortex?
Before this study started, it was already known that the structures of at least two areas of the auditory cortex are different in adult musicians than in adults without musical experience. The first area is Heschl’s gyrus, which processes basic features of a sound like its pitch (frequency) and volume (intensity)2. Thesecond is the planum temporale, which processes more complicated features of the sound, such as whether it is music, speech or background noise3.Since most studies only assess musicians in adulthood, after their subjects already accumulated lots of musical training and practice, it has so far been difficult to discern whether any of these differences were the result of nature or nurture.
To find out, the researchers took pictures of the children’s brains and compared the size of the auditory cortex in musicians and nonmusicians. They found striking differences in Heschl’s gyrus and the planum temporale. The size of Heschl’s gyrus was significantly larger in musical children compared to nonmusical children; the reverse was true for the planum temporale. Additionally, in the musical children, Heschl’s gyrus was much larger than the planum temporale; but in the nonmusical children, the planum temporale was slightly larger than Heschl’s gyrus. The size of Heschl’s gyrus also correlated to scores on the music aptitude test – children with a larger Heschl’s gyrus tended to score better.
Importantly, these differences in auditory cortex structure were already present in the youngest children, before any of them had very much training (Figure 1A). They also didn’t change significantly over the course of the study period in individuals – even as musician children got more and more training! As a result, the researchers suspect that these structural differences may be a feature of some children’s brains that somehow predispose them to musical pursuits. In other words, differences in the structure of the auditory cortex between musicians and non-musicians may be a result of nature – not nurture.
Does musical training change how the auditory cortex responds to sounds?
In adults, sounds evoke a signature set of brain waves in the auditory cortex4. In adult musicians, these waves generally start sooner after the sound than they do for nonmusicians5. This likely reflects more efficient processing of sound. These waves also tend to be larger in musicians than non-musicians, which suggests that more neurons have coordinated their activity to respond to the sound6. Previous work had indicated that in adults, musical training impacts these signature brain waves6. Are these differences already visible in children? If so, are they also influenced by training?
To address these questions, the researchers measured the brain waves of the children’s auditory cortex in response to sound. Sure enough, the researchers found a correlation between the amount of training a child had and how soon the waves started, with more musically-trained children showing quicker brain responses to sound. There was also a correlation between musical training and the size of the later portions of the signature brain waves: the more training, the larger these later waves.
However, these differences between musicians and non-musicians were evident only when considering the latest time point (17-19 years old; Figure 1C). In fact, the researchers weren’t even able to detect the signature brain waves in the youngest children in the study – the signature emerged only at the 3rd timepoint (taken at ages 11-13; Figure 1B). From this, the researchers conclude that the difference in musicians’ brain responses to sound is mostly influenced by musical practice – a product of nurture more than nature.
What’s the takeaway?
As with so many other stories in biology, it appears that musicianship doesn’t fall neatly along the lines of nature or nurture. Instead, all the evidence suggests that nature and nurture interact to produce musicians.
Of course, there are a few cautions necessary to understand these results. We must be careful how we interpret the structure differences in the auditory cortex, which were present even before the children had much musical training and correlated with musical aptitude. This does not necessarily mean that this pre-existing brain structure itself really has a strong influence on who will become a musician. Rather, it is possible that the impact of this structure on musical aptitude is initially subtle, but that adults pick on it and encourage those children towards musical hobbies from a very young age. In other words, while nature probably contributes, it is nearly impossible to fully distinguish the influence of pre-existing features from the environment a child grows up in. And of course, none of this suggests that those whose brains more closely resemble the “nonmusical” brain can’t grow up to be an incredible musician with the right practice and training! Nonetheless, this impressive 12-year study provides some of the best evidence that there may be a “musical brain” providing some natural musical aptitude, but that it must be nurtured to reach its full potential.
To read more about this topic, and to learn more about how the auditory cortex’s structure and function changes from childhood to adulthood, you can find this study at the Journal of Neuroscience website.
References
1. Schneider P, Engelmann D, Groß C, Bernhofs V, Hofmann E, Christiner M, Benner J, Bücher S, Ludwig A, Serrallach BL, Zeidler BM, Turker S, Parncutt R, Seither-Preisler A. Neuroanatomical Disposition, Natural Development, and Training-Induced Plasticity of the Human Auditory System from Childhood to Adulthood: A 12-Year Study in Musicians and Nonmusicians. J Neurosci. 2023 Sep 13;43(37):6430-6446.
2. Schneider P, Scherg M, Dosch HG, Specht HJ, Gutschalk A, Rupp A. Morphology of Heschl’s gyrus reflects enhanced activation in the auditory cortex of musicians. Nat Neurosci. 2002 Jul;5(7):688-94. doi: 10.1038/nn871. PMID: 12068300.
3. Elmer S, Hänggi J, Meyer M, Jäncke L. Increased cortical surface area of the left planum temporale in musicians facilitates the categorization of phonetic and temporal speech sounds. Cortex. 2013 Nov-Dec;49(10):2812-21. doi: 10.1016/j.cortex.2013.03.007. Epub 2013 Apr 1. PMID: 23628644.
4. Schneider P, Groß C, Bernhofs V, Christiner M, Benner J, Turker S, Zeidler BM, Seither-Preisler A. Short-term plasticity of neuro-auditory processing induced by musical active listening training. Ann N Y Acad Sci. 2022 Nov;1517(1):176-190. doi: 10.1111/nyas.14899. Epub 2022 Sep 16. PMID: 36114664; PMCID: PMC9826140.
5. Musacchia G., Strait D., Kraus N. Relationships between behavior, brainstem and cortical encoding of seen and heard speech in musicians and non-musicians. Hear. Res. 2008;241(1):34–42.
6. Shahin A, Bosnyak DJ, Trainor LJ, Roberts LE. Enhancement of neuroplastic P2 and N1c auditory evoked potentials in musicians. J Neurosci. 2003 Jul 2;23(13):5545-52. doi: 10.1523/JNEUROSCI.23-13-05545.2003. PMID: 12843255; PMCID: PMC6741225.
Cover image from Pixabay.com user sarab123
Figure 1 created using BioRender.com
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