Friday, January 21, 2011

Music and the Brain: Emotion

At the end of my primer on music and the brain, I said that the research I intend to discuss attempts to answer these questions:

  • How is emotion tied to the experience of enjoying music?
  • What physiological or chemical cues can tell us more about how the brain interprets music?
  • What is the role of anticipation in the brain when listening to music?

  • I meant to include two studies in this post (as well as a section of additional commentary!) but my writing about the first one was too extensive.  The second study (the one in recent news) will be discussed in my next post.

    ResearchBlogging.orgSalimpoor, V., Benovoy, M., Longo, G., Cooperstock, J., & Zatorre, R. (2009). The Rewarding Aspects of Music Listening Are Related to Degree of Emotional Arousal PLoS ONE, 4 (10) DOI: 10.1371/journal.pone.0007487
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    The authors of this study begin their introduction with this:
    Why is music pleasurable?...there are no direct functional similarities between music and other pleasure-producing stimuli: it has no clearly established biological value (cf., food, love, and sex), no tangible basis (cf., pharmacological drugs and monetary rewards), and no known additive properties (cf., gambling and nicotine).  Despite this, music is consistently ranked amongst the top ten things that individuals find highly pleasurable...
    Seen through the lenses of psychologists, "Why is music pleasurable?" becomes an investigation of "whether there is a systematic relationship between dynamic increases in pleasure states and physiological indicators of emotional arousal."  The authors determined that if they could monitor a person's subjective feelings of pleasure simultaneously against objective measurements of emotional arousal, they could begin to confirm their hypothesis.  That wouldn't be enough, however, unless they also demonstrate that when listener's do not find a piece of music to be pleasurable, physiological indicators of emotional arousal remain static; this is opposed to the possibility of such indicators responding to the stimuli of music without an accompanying change in felt emotion.  If one subject listens to a musical excerpt that they enjoy so much it gives them chills, and another subject listens to the same piece of music and feels emotionally unswayed by it, the measurements of physiological indicators of emotion would be able to determine whether musical pleasure is a result of measurable emotional increase or if, instead, musical pleasure is unrelated to emotional arousal.  In the authors' words,
    We tested the hypothesis that if the rewarding aspects of music listening are indeed a result of the emotional states produced, there would be a positive correlation between emotional arousal and pleasure states.  It further follows that a lack of pleasurable responses should also be accompanied by low emotional arousal.
    I struggled at first to differentiate the psychological ideas of "pleasure" and "emotion" as they are used here, for I'm used to identifying pleasure as an emotion by definition.  To separate the two, I gave consideration to things I would consider pleasurable that are doubtfully related to physiological changes in my body and brain that have been established as the causes of emotion.  Laying in bed on a Saturday morning with no plans, I may be awake but stationary for minutes at a time, simply enjoying being relaxed.  This kind of relaxed enjoyment does not, in my understanding, fit into the category of an emotional experience as defined by observed physiological signatures.  I hope that helps.

    These researchers chose a novel approach to experimenting with music and emotion by using only music selected by participants in their study.  They sought subjects who experience chills (an interesting and established phenomenon considered valuable in music and emotion research) while listening to particular pieces of music.  Then they used these selections for all participants, and linked each selection to two people: one who loves it and gets chills, and one who recognizes it and finds it neutral or boring.

    By using participant-selected music, they were able to get very reliable results regarding chills, and by using the same piece of music for a participant who finds it boring, they were able to negate all of the factors that musical stimuli produce and thereby compare emotional arousal most effectively.  Success in this would add much to the "little empirical evidence to suggest that emotional arousal is directly related to music's rewarding properties."

    Subjects would be hooked up to devices measuring skin conductance (GSR), temperature, heart rate, blood volume pulse amplitude, and respiration rate.  This data would be measured while they listen to music, and they would also press buttons on another device to indicate whether they were experiencing "low pleasure," "high pleasure," "chills," or were relatively "neutral."

    Ultimately, I'm convinced that they succeeded in confirming their hypothesis with "data [that] revealed a strong positive association between subjective ratings of pleasure and autonomic nervous system arousal," and by demonstrating that "participants who reported to increases in pleasure in response to...the same excerpts did not show any significant increases in [emotional measurements]."

    I've just started reading Emotion and Meaning in Music by Leonard B. Meyer.  This 1956 treatise discusses two ideas that relate to this study.  In the first chapter, Meyer defines in detail the philosophical and psychological understanding of emotion and argues, persuasively, that psychophysiologically, one emotion is indistinguishable from another — emotional arousal is always the same, and the emotion that is ultimately felt and claimed by a person depends on the stimuli or context at hand.  For instance, skydiving can be extraordinarily exciting while falling off a tall building would be frightening, yet the physiological sources of emotion would be quite the same,  though experienced differently.  Based on my reading of this study, that argument seems to be the predominant viewpoint today.  He also lays out an excellent foundation for the pursuit of a more objective understanding of how anticipation is involved and manipulated in music.  Music is unique in that a piece of music creates its own context and is self-referential, enabling a listener's anticipation and expectancies to be manipulated with great accuracy.  The next study deals more directly with anticipation, but there is a figure from this one that provides good visual sneak preview.

    (Oh, by the way, the authors of this paper actually cite Meyer's book.  In addition, they also cite David Huron's Sweet Anticipation: Music and the Psychology of Expectation (2006), which is, coincidentally, resting on my table as the next book on my reading list.  I suppose this means I'm reading the right materials, which makes me happy.)

    In addition to all of this, there were two secondary pursuits within this study.  The first was regarding the chills that participants experienced; they sought to further confirm the value and understanding of them.  They found that "over 80% of chills occurred at the highest moments of pleasure," which is nice, but now I wonder what was different about the 20% of chills that occurred at moments that did not "correspond with peak pleasure responses."

    The second was practically a jab at other music research.  They demonstrate through surveying participants that the emotions they felt in response to the musical selections were not necessarily the same as the emotions that they thought the music intended.  The authors conclude,
    This finding reveals a major flaw in current paradigms of research with music and emotions, with compulsory implications for future studies.  Although it seems intuitive that felt emotions are different than perceived emotions, this distinction has not been acknowledged in the majority of previous studies.

    At the end of the Discussion section of the paper, the authors make a tantalizing note: "The intensity of pleasure experienced...has lead some researchers to suggest that [music] may act upon the dopamine reward system of the brain," and that "whether or not dopamine is actually involved remains to be determined..."  This question directly led to the 2011 research discussed in my next post, and, if true, would add another piece of the brain to the growing list of those known to be involved in listening to music.


    1. Excellent summary! Scientific writing is sometimes a bit difficult to access for the nonspecialist reader but you've done a good job of capturing the main points of the study.

    2. In response to your last sentence: It's not just listening to music. I understand that is the basis of the study, but think of how much of the brain is used in making music that is not included when simply listening to it.

      Otherwise, I am enjoying these summaries.

    3. Music and Emotions

      The most difficult problem in answering the question of how music creates emotions is likely to be the fact that assignments of musical elements and emotions can never be defined clearly. The solution of this problem is the Theory of Musical Equilibration. It says that music can't convey any emotion at all, but merely volitional processes, the music listener identifies with. Then in the process of identifying the volitional processes are colored with emotions. The same happens when we watch an exciting film and identify with the volitional processes of our favorite figures. Here, too, just the process of identification generates emotions.

      An example: If you perceive a major chord, you normally identify with the will "Yes, I want to...". The experience of listening to a minor chord can be compared to the message conveyed when someone says, "No more." If someone were to say these words slowly and quietly, they would create the impression of being sad, whereas if they were to scream it quickly and loudly, they would be come across as furious. This distinction also applies for the emotional character of a minor chord: if a minor harmony is repeated faster and at greater volume, its sad nature appears to have suddenly turned into fury.

      Because this detour of emotions via volitional processes was not detected, also all music psychological and neurological experiments, to answer the question of the origin of the emotions in the music, failed.

      But how music can convey volitional processes? These volitional processes have something to do with the phenomena which early music theorists called "lead", "leading tone" or "striving effects". If we reverse this musical phenomena in imagination into its opposite (not the sound wants to change - but the listener identifies with a will not to change the sound) we have found the contents of will, the music listener identifies with. In practice, everything becomes a bit more complicated, so that even more sophisticated volitional processes can be represented musically.

      Further information is available via the free download of the e-book "Music and Emotion - Research on the Theory of Musical Equilibration:

      or on the online journal EUNOMIOS:

      Enjoy reading

      Bernd Willimek, music theorist