Biology 202
2004 Second Web Paper
On Serendip

There is a beautiful passage in a book called "Home of the Gentry", by Ivan Turgenev, where the protagonist of the novel listens to a piece of music being played on the piano that touches him to the very depths of his soul. I will quote part of this passage, since it describes very eloquently the almost mystical power that music wields over the human mind, a power which I find fascinating.

"The sweet, passionate melody captivated his heart from the first note; it was full of radiance, full of the tender throbbing of inspiration and happiness and beauty, continually growing and melting away; it rumoured of everything on earth that is dear and secret and sacred to mankind; it breathed of immortal sadness and it departed from the earth to die in the heavens." (10)

The tremendous ability that music has to affect and manipulate emotions and the brain is undeniable, and yet largely inexplicable. Very little serious research had gone into the mechanism behind music's ability to physically influence the brain until relatively recently, and even now very little is known about the neurological effects of music. The fields of music and biology are generally seen as mutually exclusive, and to find a Neurobiologist also proficient in music is not very common. However, some do exist, and partly as a result of their research some questions about the biology of music have been answered. I will attempt to summarize some of the research that has been done on music and the brain in recent years. I will focus in particular on music's ability to produce emotional responses in the brain.

One great problem that arises in trying to study music's emotional power is that the emotional content of music is very subjective. A piece of music may be undeniably emotionally powerful, and at the same time be experienced in very different ways by each person who hears it. The emotion created by a piece of music may be affected by memories associated with the piece, by the environment it is being played in, by the mood of the person listening and their personality, by the culture they were brought up in: by any number of factors both impossible to control and impossible to quantify. Under such circumstances, it is extremely difficult to deduce what intrinsic quality of the music, if any, created a specific emotional response in the listener. Even when such seemingly intrinsic qualities are found, they are often found to be at least partially culturally dependant.

Several characteristics have been suggested that might influence the emotion of music. For example, according to one study (11)(12), major keys and rapid tempos cause happiness, whereas minor keys and slow tempos cause sadness, and rapid tempos together with dissonance cause fear. There is also a theory that dissonance sounds unpleasant to listeners across all cultures. Dissonance is to a certain degree culture-dependent, but also appears to be partly intrinsic to the music. Studies have shown that infants as young as 4 months old show negative reactions to dissonance. (3)(6)(9)

It is possible to both see and measure the emotional responses created by music in the brain by using imagery techniques such as PET scans. However, as these emotional responses would generally be caused by factors out of the experimenter's control, the data collected would be very difficult to interpret.

A recent experiment dealt with this problem by attempting to minimize subjectivity, by measuring responses to dissonance. (1) Dissonance can consistently create feelings of unpleasantness in a subject, even if the subject has never heard the music before. Music of varying dissonance was played for the subjects, while their cerebral blood flow was measured. Increased blood flow in a specific area of the brain corresponded with increased activity. It was found that the varying degrees of dissonance caused increased activity in the paralimbic regions of the brain, which are associated with emotional processes.

Another recent experiment measured the activity in the brain while subjects were played previously-chosen musical pieces which created feelings of intense pleasure for them. (2) The musical pieces had an intrinsic emotional value for the subjects, and no memories or other associations attached to them. Activity was seen in the reward/motivation, emotion, and arousal areas of the brain. This result was interesting partly because these areas are associated with the pleasure induced by food, sex, and drugs of abuse, which would imply a connection between such pleasure and the pleasure induced by music.

Experiments such as these are not able to answer such questions as how or why the emotional responses were created in the first place. However, their results can still be informative. These two experiments both show that music has the power to produce significant emotional responses, and they localize and quantify these responses within the brain.

Another quantifiable aspect of emotional responses to music is its effect on hormone levels in the body. (5)(7) There is evidence that music can lower levels of cortisol in the body (associated with arousal and stress), and raise levels of melatonin (which can induce sleep). (5) This is outwardly visible in terms of music's ability to relax, to calm, and to give peace. Music is often used in the background hospitals to relax the patients, or in mental hospitals to calm potentially belligerent patients. It also can cause the release of endorphins, (7) and can therefore help relieve pain.

Love for and appreciation of music is a universal feature of human culture. It has been theorized that music even predates language.(8) There is no question that music has grown to be an important part of human life, but we can only guess why. It has been theorized that music is important evolutionarily, (8) but all such theories are at this point conjecture. No concrete evidence has been found that music is evolutionarily beneficial. There are many questions one could ask about the powerful link between music and the brain, but very few answers exist. How does music succeed in prompting emotions within us? And why are these emotions often so powerful? The simple answer is that no one knows. We are able to quantify the emotional responses caused by music, but we cannot explain them.

References

1) Blood, A.J., Zatorre, R.J., Bermudez, P., and Evans, A.C. (1999) "Emotional responses to pleasant and unpleasant music correlate with activity in paralimbic brain regions." Nature Neuroscience, 2, 382-387.

2) Blood, A.J. & Zatorre, R.J. (2001) "Intensely pleasurable responses to music correlate with activity in brain regions implicated with reward and emotion."Proceedings of the National Academy of Sciences, 98, 11818-11823

3) Harvard Gazette Archives. Cromie, William J. (2001) "Music on the brain: Researchers explore biology of music."

4) Harvard Gazette Archives. Cromie, William J. (1997) "How Your Brain Listens to Music."

5) Musica Humana. Heslet, Prof. Dr. Lars. "Our Musical Brain"

6) transcript of episode of Closer to Truth. "What Makes Music So Significant?" Interview with Jeanne Bamberger, Robert Freeman, and Mark Tramo, conducted by Robert Kuhn.

7) Time Reports. Lemonick, Michael. (2000) "Music on the Brain: Biologists and psychologists join forces to investigate how and why humans appreciate music."

8) Levitin, Daniel J. "In Search of the Musical Mind", (2000) Cerebrum, Vol 2, No 4

9) Tramo, Mark Jude. "Biology and music: Enhanced: Music of the Hemispheres." (2001) Science, Vol 291, Sigue 5501, 54-56

10) Turgenev, Ivan. Home of the Gentry.

11) "The Biology of Music.", (2000) The Economist

12) "Exploring the Musical Brain", (2001) Scientific American

13) The Power of Music


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