Tuesday, October 29, 2013

Music, the Brain, and Pleasure: An Update of Robert Jourdain

Robert Jourdain's Music, the Brain, and Ecstasy is an excellent primer on how the human brain perceives and processes music, covering the musical experience from sound waves reaching the eardrum all the way to the emotional catharsis of a symphony or string quartet. However, since the book's publication in 1997 there has been considerable research not only into the workings of the brain, but also into the neuroscience of music specifically. In this essay I will summarize some of this research in order to update Jourdain's writing on emotion and pleasure in music.

Jourdain (1997) deals with the subject of pleasure in music in the last chapter of the book, titled "Ecstasy." In this chapter, he sets out to answer the following three questions: "First, how is it that music elicits emotions from us? Second, how is it that music gives us pleasure? And third, what is happening in our brains when music leads us to the threshold of ecstasy?" (p. 304) As Jourdain explains, these three questions are intertwined; all are related to anticipation and its fulfillment - or not. Drawing on then-current research, Jourdain explains that emotion stems from the oldest part of the brain, the limbic system, and is important in reasoning (pp. 308-309). Ultimately, emotion is a way for our nervous systems to figure out what activities are most important, a way of directing attention among incoming experiences (p. 309). We plan activities and carry them out by anticipating the results and then satisfying that anticipation (or trying to). Emotions occur when the result does not line up with our anticipation. If the result is better than we expected, we experience a positive emotion; if the result is worse, we experience a negative emotion. Similarly, pleasure is experienced when our expectations or anticipations are fulfilled (p. 312). Unfulfilled expectations cause stress as the brain tries to reassess the situation in order to make a better prediction next time; however, even greater pleasure can be caused by delaying or subverting expectations in order to heighten the sensation of resolution when it finally occurs (p. 319). Music is filled with instances of anticipation and resolution, and as such it makes sense that it should be able to generate both emotions and pleasure in the listener. A well-known example of this is Richard Wagner's opera Tristan und Isolde, whose prelude sets up one unresolved tension after another - tensions that continue for almost the length of the opera, culminating in a tremendous resolution in Isolde's final aria. It is an incredibly evocative depiction of ecstasy, the subject of Jourdain's third question. Of course, the word "ecstasy" is inherently subjective and next to impossible to measure in a scientific way. Jourdain asserts that, "By providing the brain with an artificial environment, and forcing it through that environment in controlled ways, music imparts the means of experiencing relations far deeper than we encounter in our everyday lives... In this perfect world, our brains are able to piece together larger understandings than they can in the workaday world, perceiving all-encompassing relations that go much deeper than those we find in ordinary experience... It's for this reason that music can be transcendent." (p. 331)

Recent research into the science of pleasure and emotion may shed some new light on these ideas. Jourdain notes that, "remarkably, 'pleasure' is a concept seldom encountered in neuroscience or even in psychology. There's hardly a book written on the subject." (p. 315) Happily, this is no longer quite as true as it was in 1997. An iimportant development is that the role of dopamine in musical pleasure is now better understood. A number of studies have examined the role this neurotransmitter plays in music listening, linking musical pleasure to the brain’s reward system. One important study was by Benovoy, Dagher, Larcher, Salimpoor and Zatorre in 2011. In this study, researchers used both PET and fMRI technology to scan subjects who were listening to either a favourite, pleasurable piece of music. Using PET to trace the presence of dopamine and fMRI to determine the timing of dopamine release, the researchers found that chills associated with high levels of pleasure at the climax of a piece of music coincided with the release of dopamine in the nucleus accumbens. Additionally, the researchers found that dopamine spiked about 15 seconds before the emotional climax of the piece as the subject anticipated the most pleasurable section of the music; however, this dopamine activity took place in the caudate (Benovoy et al., 2011). 

This research is intriguing for several reasons. First, it directly links dopamine activity to the experience of musical pleasure, which had not been previously demonstrated. Second, it illustrates that anticipation and fulfillment constitute two different types of musical pleasure that occur in different parts of the brain. The study supports Jourdain's assertion that "...the deepest pleasure in music comes with deviation from the expected... Isn't this contradictory? Not if the deviations serve to set up an even stronger resolution” (Jourdain, 1997, 319). If dopamine is released each time the listener expects a resolution, only to find that the music takes a different turn, the final resolution will be that much more intense, as in Tristan. The study also answers a question raised in the book: "...why we continue to find music expressive after we have heard a piece a few times and know where its expressive deviations will fall." (Jourdain, 1997, 313) Clearly, familiarity with a piece allows the listener to anticipate the most pleasurable moments, releasing dopamine and creating the added pleasure of anticipation. (As an aside, I wonder if this may be why so many musicians and listeners - myself included - become attached to one particular recording of a piece. If we are anticipating certain expressive gestures and don't hear them because the performers have made a different choice, might our anticipation be unfulfilled, leaving us to experience a negative emotion?)

Benovoy et al. (2011) dealt with dopamine activity while listening to a piece of music that the subjects already knew well and loved. But what about unfamiliar music? It is clear that, while familiarity with a piece may increase pleasure in hearing it, unfamiliar music can have the same pleasurable effect. Salimpoor et al. (2013) conducted another experiment to find out what happens in the brain when a subject listens to music that he or she has never heard before. According to Salimpoor and Zatorre (2013), "[i]t has been proposed that all individuals have a 'musical lexicon', which represents a storage system for... information about the relationships between sounds and syntactic rules of music structure specific to their prior experiences” (p. 10434). Or, in other words, throughout the course of their lives, individuals learn the musical rules and structures of their particular culture, allowing them to form expectations and anticipations even when hearing a new piece of music, as long as it falls within their own cultural tradition. In this study, Salimpoor et al. (2013) used fMRI to monitor neural activity while subjects listened to a previously unknown piece of music. They then asked the subjects to rate the desirability of that piece of music by giving them a chance to purchase it in an auction model, so that higher bids demonstrated higher desirability or musical pleasure. They found that highly-rated music coincided with increased activity in the mesolimbic system, particularly the nucleus accumbens - the same area of the brain that was associated with dopamine release upon fulfillment of musical expectations in the previous study. Salimpoor and Zatorre (2013), in a review of studies on musical pleasure, conclude that the cortical system is able to make sense of music's structure and rules and therefore make predictions, while the older striatal dopaminergic system creates the emotional, pleasurable response to music in the brain's reward system. Thus humans are able to take pleasure in an abstract aesthetic reward such as music.

Jourdain’s description of musical pleasure as a series of expectations or anticipations followed by fulfillment is essentially correct; however, the role of dopamine in the neural workings of musical pleasure was not yet understood at the time his book was published. Recent research confirms Jourdain’s assertions and helps us to understand how the abstract pleasure of music taps into our evolved rewards systems.

Works Cited

Jourdain, R. (1997). Music, the brain, and ecstasy: How music captures our imagination. New York, NY: Harper Perennial.

Benovoy, M., Dagher, A., Larcher, K., Salimpoor, V.N., and Zatorre, R.J. (2011). Anatomically distinct dopamine release during anticipation and experience of peak emotion to music. Nature Neuroscience, 14(2), 257-262. http://dx.doi.org.myaccess.library.utoronto.ca/10.1038/nn.2726

Salimpoor, V.N., van den Bosch, I., Kovacevic, N., McIntosh, A.R., Dagher, A., and Zatorre, R.J. (2013). Interactions between the nucleus accumbens and auditory cortices predict music reward value. Science 30(6129), 216-219. doi: 10.1126/science.1231059.

Zatorre, R.J., and Salimpoor, V.N. (2013). From perception to pleasure: Music and its neural substrates. 
PNAS 110(2), 10430-10437. doi: 10.1073/pnas.1301228110

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