Extra Credit_ “Brain Networks for Tracking Musical Structure” by Madeline Schwarz

I was particularly excited to attend Petr Janata’s Friday lecture at the Sound and Science Symposium, as I am an aspiring neuroscientist, and through dance am immersed in music on a daily basis, so I am always intrigued by research combining the two. From UC Davis’ Department of Psychology and the Center for Mind and Brain, Janata is a cognitive neuroscientist who has done extensive work investigating how music evokes autobiographical memories.

Janata first gave a well-rounded introduction of the technical structure of music, in terms of tonal space (to which most of his research is devoted), rhythmic space, and timbral space. He posed the questions that drive most of his studies: how does the brain represent these spaces and track music’s movement through them, and how is our emotional experience of music shaped by this movement? How can we use models of tonal space to understand structures in the brain?¬†

Janata discussed two distinct organizational systems of viewing the brain: in terms of perception/action systems, and endo-orienting and exo-orienting attentional networks. Both ways of visualizing cognition are applicable to processing music; while I can view listening to music as more passively hearing and interpreting vs. making active predictions about what will come next, I can also understand the theory of relating inwardly to music vs. focusing on external stimuli when tracking musical structure. Whatever way you choose to view it, both sides of these organizational spectrums are engaged during the processing of music, depending on how we’re listening. Janata demonstrated this through his study in which he asked subjects to either focus on the entire piece of music or selectively attend to one instrument; depending on the task, differeont parts of the attentional system were active.

Janata also explained basic Western music theory before ¬†elaborating on his hypotheses about music and the brain; he explained how octaves are increases in frequency, and each key is named after the most “stable” note in the set.

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Our brains naturally represent tonal space in terms of which keys are more similar to one another, corresponding with the circle of fifths. In actuality, this representation is toroidal in shape, and Janata and his colleagues have created a program which maps songs as flattened tori (here is one such animation of “Girl from Ipanema“). I found this portion of the lecture extremely fascinating, as Janata was explaining a way to look at the artistic creation of music in a purely neuroscientific way, using technology to visually represent this connection.

Janata's mapping of Norah Jones' "Don't Know Why"

Janata's mapping of Norah Jones' "Don't Know Why"

After giving us a crash course in the way the brain interprets musical structure, Janata discussed his research about what brain regions were activated when we engage with music. Through BOLD signals from MRI, he found that the medial prefrontal cortex was activated frequently - a region which has been linked with self-referential and social cognitive judgments about presented stimuli. However, in a separate study, he found that this region was most frequently activated when the music evoked autobiographical memories in the subject (in which case, other areas linked with episodic and semantic memory retrieval were also used), whereas when the subject was more focused on the valence (pleasant or displeasant nature) or familiarity of music, different parts of the brain were more active. 

Therefore, Janata’s studies seemed to indicate that music interpretation in the brain is not confined to one particular region or set of regions; it spans the entire cortex, and the specific regions activated at any given instant correspond with where our attention lies in thinking about the music. Moreover, these studies are also helping neuroscientists understand the functional purpose of these areas in the brain through the detailed observation of a complicated cognitive process. I thoroughly enjoyed his presentation, and aspire to not only learn more about this area of research, but to potentially become involved in conducting these sorts of studies in the future.

- Madeline Schwarz

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