A recent review of the literature on music and brain plasticity was recently published in Nature Neuroscience Reviews. The authors address a very interesting question that I have been writing about now for years – how widespread are the effects of mental training on overall cognitive function?

We know that the vertebrate brain displays considerable plasticity – it learns and remembers. When you train at a task, you get better at it. For example, I can type pretty fast. I don’t have to think about where the keys are, and I don’t even have to look at the keyboard. I just think of the words I want to type and my fingers fly effortless over the keyboard. This is a product of decades of typing.

Anyone who has learned to play a musical instrument is also familiar with brain plasticity. After years of playing, the complexity and subtlety with which you can perform on an instrument becomes impressive. You don’t have to think consciously about every move – you just feel it. Further, your ear is more sensitive to subtle aspects of pitch, tone, timing, and timbre. You notice things other people don’t notice.

That much is very clear from the research and not controversial. This new paper reviews the evidence which establishes that these changes in ability that accrue with music training result in changes to the brain itself – the relevant areas of the brain that involve auditory processing and motor control are larger and more active in musicians than non-musicians, and this correlates with age of onset of training and duration of training.

In addition, the brain changes associated with musical training occur at cortical and sub-cortical levels – meaning in the parts of the brain that involve auditory processing prior to conscious awareness. And again, this applies to music and language.

But when we move beyond this basic fact of neural plasticity, we start to get into some controversy. The next question is – do increases in auditory function that directly relate to music training extend to auditory processing in general? Would they apply, for example, to the auditory processing of language?

There is also a further question beyond that – does musical training improve brain function in areas not related directly to auditory processing or motor control? Does musical training make people “smarter” by improving their memory, attention, or other generalizable mental skills?

I have gone back and forth on this question over the years, as conflicting evidence comes in. Recently I have been leaning toward a negative conclusion – that training in one area does not significantly affect other cognitive areas. Last month, for example, I reported on a Nature study that showed no such effect. “Brain training” improves the task that is being trained, but does not appear to transfer to other tasks.

What does this latest review have to say about music? They report:

Below, we describe data that support the view that the fine-grained auditory skills of musicians, which are acquired through years of training, percolate to other domains, such as speech, language, emotion and auditory processing. Thus, music training improves auditory skills that are not exclusively related to music.

They go on to discuss the fact that the processing of language involves many of the same cognitive skills as music: discriminating changes in pitch, deriving information from sound, and directing attention toward the details of sound. This makes perfect sense. In fact I would go beyond that to speculate that our appreciation for music may in fact be an evolutionary outgrowth of language itself. From an evolutionary point of view, music may be a side consequence of our adaptation for spoken language.

An excellent example presented in the paper is that of processing regularities in auditory sensory input. When trying to separate the sound of a person speaking from background noise, auditory processing in the brain looks for statistical regularities in the sound, distinct from the randomness of background noise. So the processing is there to appreciate regularities. This same processing gives us an appreciation for the regular timing in music. It is an excellent example of how evolutionary adaptation can result in “unintended consequences.”

But further it creates the potential to improve the ability to distinguish speech from background noise through musical training, since the same underlying neurological processing is involved.

But what about the final question – does music training percolate to other areas of cognition not related to auditory processing or the motor skills required to play an instrument? (This is the alleged “Mozart” effect, which has not been supported by research.) The paper does not discuss this question, or review any evidence that directly bears on it.

Conclusion

This is a very interesting review, and is an excellent overview of the research on the effects of music training on the brain and its implications for language ability. But the review does not present any evidence to suggest that music training has neurological benefits that extend beyond the brain processing involved in music (which overlaps with language). The “Mozart effect” remains dead.

This review also does not alter my opinion regarding brain training in general – mental training improves the tasks that are trained, and the underlying neurological processing, but not cognitive areas that are not directly related to the tasks that are being trained.

At the end of the article the authors advocate for increased music training as part of basic education. I think they make a reasonable argument for this. Language function is a core cognitive skill, and music training does seem to enhance the auditory processing of language. But I caution against extrapolating beyond the limited implications of the research.