Monday, September 24, 2012

Notes & Neurons: In Search of the Common Chorus

Schaefer, John, Lawrence Parsons, Daniel J. Levetin, Bobby McFerrin and Janshed Bharucha, narr. Notes & Neurons. 2009. World Science Festival 2009. Web. 21 Sept. 2012. <>.

In this session of the World Science Festival 2009, host John Schaefer joined neuroscience researchers Dr. Lawrence Parsons, Dr. Daniel J. Levitin, Dr. Jansched Bharucha and musician Bobby McFerrin to discuss how music affects the human brain and why people are drawn to music.  Dr. Daniel Levetin, head of the Laboratory for Music Perception, Cognition and Expertise at McGill University began the dialogue by discussing the reason neuroscientists are interested in music.  He explained that the field of neuroscience studies all human behavior, and he argued that there is nothing more human than music, as music was present since the beginning of known human history.  Sound, from a neuroscientist’s point of view, is not just a series of vibrations.  It is a “construction of the brain” at the end of a long chain of neuro-processing events.  Dr. Lawrence Parsons, professor of cognitive neuroscience at the University of Sheffield in the United Kingdom expanded upon Dr. Levetin’s point by suggesting that music is unique as it requires almost every area of the brain during its processing, creating a “whole nervous system experience”.  
Musician Bobby McFerrin then asked the panel an interesting question. “Do we experience music differently when we are planning to experience it than when the experience is unplanned?”  In other words, if a person goes to a concert, will that music be processed differently than if it was unexpectedly heard while the person was walking down the street?  Dr. Parsons explained that although the brain forms expectations of what will occur musically, it functions so quickly that the experiences are processed in virtually the same manner.  Varied types of expectations do, nevertheless have a great deal of effect on how music is processed, as demonstrated in an experiment performed by Dr. Jansched Bharucha, Provost and Senior Vice President of Tufts University.
Dr. Bharucha and Dr. Levetin described how the universal function is to form social cohesion by aligning the brain states of communities.  There are aspects of music, however, that are very culturally specific.  While listening to music, the brain is continuously forming micro-predictions about pitch and timing.  When a person hears a fragment of music, the rest is “filled in” based on cultural expectations.  This urge can be so strong that a person may “misremember” a melody they heard, mentally “fixing” it to fit within their cultural expectations.
Dr. Bharucha demonstrated this by having singers in India listen to an incomplete piece of music based on an Indian raga, or scale, and by having them improvise whatever they thought the rest of the melody should be.  The Indian singers consistently sang tunes using the notes found within the raga.  The same experiment was then conducted in the United States with American singers.  Instead of singing notes that would fit within the raga of the song they were listening to, the American singers sang melodies that used notes from traditional Western scales.  After the American singers had participated in the experiment for a number of times, however, a notable change began to occur.  Some of the singers’ brains began to adapt their expectations to that of the Indian ragas, and they began to invent melodies within the Indian scales.   This experiment demonstrated the brain’s plasticity, or its ability to adapt and change.  Dr. Bharucha displayed a diagram that showed how the brain forms neuro-pathways over time as it experiences certain sequences of pitches repeatedly.  The brain then “expects” certain combinations of pitches because of its past experiences. 
            An additional experiment conducted by Dr. Bharucha demonstrated how western culture has developed emotional associations with certain intervals.  Researchers recorded actors reading phrases with varied emotions.  They found that a prevalence of the interval of a minor third was associated with sadness, while the interval of a line of ascending semitones was associated with anger.  Dr. Levatin added to the discussion of emotions and music by explaining that timbre is also an important part of emotional signaling that individual cultural groups share.  Somehow, cultural groups are able to recognize subtle changes in timbre, and have developed communal expectations as to what they communicate. 
At the end of the discussion, a group of both Western classical and Indian classical musicians joined Bobby McFerrin and the researchers in a musical improvisation. 

            This video was an excellent introduction into the world of music and neuroscience for someone who is new to the field.  Not only did it explain the basic components of music and how they related to the brain, it also demonstrated how so much of music’s effect on the brain is still a mystery.  I find the idea that our brains are musically “trained” by cultural experiences fascinating.  If our musical experiences are so influenced by our cultural exposure, this leads me to wonder if our individual tastes are also programmed by our experiences.  Why, for example, do some people love country music, while others can’t stand the sound and will only listen to rap?  What is it that draws a person to the music of a particular artist or genre?  Is it their exposure to that style that teaches them to expect certain patterns associated with that style?  Or is it something else hidden within the recesses of the brain that dictates individual tastes? This is definitely a question that warrants further exploration on my part.  

No comments: