The Musical Mind - How the Brain Appreciates Music

A brain with superimposed musical notes.
How does music cause our brain to respond?. Getty Images

"The brain," musical composer and professor Joseph Waters told me, "is a pattern recognition machine."

I was tinkering on the keyboard of an electronic piano, trying to transform rhythmic digital bleeps into something that moved others' souls. I had some musical training but had never tried to compose. I knew nothing of musical theory. All I could do was pound notes into the computer, listen to what played back to me, and feel whether the music was "right" or not.

Sometimes I felt it needed something more, or needed to be deleted entirely. Eventually, the piece literally sang for me.

At the end of Joseph Waters' electronic composition class, we heard what we had created. Some of the pieces I liked, some I didn't. Some made me happy, others made me sad. And like many good classes, I left with more questions than answers.

"Is it not strange," mused Shakespeare in Much Ado About Nothing, "that sheep guts should hale souls out of men's bodies?" The organic strings of Elizabethan lyres and the electronic tones of modern keyboards have the same target -- the strange combination of biological tissue and electrical signals that make up the human brain and mind.

How do the waves of compressed air that move our eardrums lead to tapping feet or teary eyes? How does someone with no musical training know whether a piece of music feels right or not? Why can a particular piece of music make our friend smile but leave us cold?

Music and You

We are our brains, and few things affect us, and therefore our nervous systems, like music can. Neuroscientists have naturally wondered about this universal and quintessentially human phenomenon. While other animals, such as birds or whales, make use of music for communication, humans are uniquely fanatic about musical creation and consumption.

One way of approaching these questions is by studying extraordinary cases. For example, some people who have a traumatic or ischemic lesion in particular parts of their brain suffer from amusia -- that is, they can no longer produce or appreciate musical sounds. In the rare disorder musicogenic epilepsy, hearing certain songs (even good songs) can produce epileptic seizures. The genetic condition Williams syndrome is associated with intense musical interest, but diminished abilities in other cognitive domains.

By studying such unique cases and making use of other investigative techniques, neuroscientists have begun to better understand music's mysteries. Some find it useful to divide music appreciation into three components: perceiving the sounds, recognizing music, and experiencing emotions.

Perceiving Sounds

As soon as sound waves hit the eardrum, the nervous system begins to organize the sound. Hair cells in the cochlea of the inner ear are arranged so that low frequencies stimulate cells near the apex and high frequencies hit the cochlear base.

This organization is maintained as the signal is transmitted through the nuclei of the brainstem up into the medial geniculate nucleus of the thalamus. From this nucleus, auditory signals are relayed out to the cortex of the brain on the part of the temporal lobe.

Recognizing Music

The anatomy and physiology of music recognition are not as well understood as the basics of sound perception. This part of musical appreciation occurs in the frontal and temporal lobes, an evolutionarily newer part of the brain that varies substantially from individual to individual. The frontal lobes are particularly involved with the kind of pattern recognition mentioned by music professor Joseph Waters, so is likely involved with recognizing different chords, rhythms, and musical themes.

Some researchers have studied how musicians perceive music as opposed to non-musicians. Some imaging studies have shown that when listening to music, the left hemisphere of the brain becomes more involved in musicians than in non-musicians. The left hemisphere of the brain is classically considered to be more analytical than the right, suggesting a more technical appraisal of music in more highly trained listeners.

Music and Emotion

While the frontal lobes can help identify and perceive different aspects of music, there's certainly more to music than intellectual analysis. The emotions provoked by music are what keep most of us coming back for more. One of music's complexities is that the character of the music does not completely correlate with our own emotional experience. For example, we can listen to a tragic aria and feel a degree of sorrow, while simultaneously enjoying the experience enormously.

Our ability to say how a bit of music is intended to make us feel correlates with developmental age in children. As children get older, the ability to correlate major keys and faster tempos with happiness and minor keys and slow paces with sorrow becomes more consistent. This aspect of musical appreciation has been tied to activity in the left frontal lobe and bilateral posterior cingulate cortex.

We feel the power of some music with our entire body. Pleasurable music activates the brain's ventral tegmental area, a reward center that is also activated by romantic love and addictive drugs. The ventral tegmental area participates in a neural circuit that includes the hypothalamus, a brain center linked to the body's autonomic nervous system. This can result in increased heart rate, changes in breathing pattern, and even the sensation of "chills."

Coda:

Music is fundamental to our brain's function. Music soothes us as infants and is frequently one of the most resistant brain functions against the ravages of dementia when we age. The effect of music on mankind is ancient. The first evidence of human musical instruments dates back about 50,000 years from a bone flute found in a cave. Many people feel that one of the most revealing things they can learn about another human lies in their taste in music. By learning how the brain appreciates music, neuroscientists hope to learn more about what it is that makes us uniquely and especially human.

Sources:

Steven A Sparr, Amusia and musicogenic epilepsy. Current Neurology and Neuroscience Reports (2003) Volume: 3, Issue: 6, Pages: 502-507

The Musical Brain: Myth and Science. Antonio Montinaro World Neurosurgery May 2010 (Vol. 73, Issue 5, Pages 442-453).

Brandy R. Matthews, Chapter 23 The musical brain, Handbook of Clinical Neurology 2008;88():459-469.

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