Author Archives: Ryan Shin

Turn Up the Bass!

If you really knew me, you would know that a huge slice of my life is devoted to music. To me, music is another language, another culture, and another lifestyle. There’s so many things you can do with music: play, listen, learn, write, and produce. You can even relate to, dance and communicate with, or supplement action-packed movie scenes with music. The possibilities with music are endless. That’s why I decided on pursuing a minor in music – while I wanted to mainly focus on neuroscience and pre-med, there was no way I was just going to stop my progression of music.

A little more than one week remains in our Parisian stay, and our main objective this week was to keep cool in the immense heat. However, the heat didn’t keep me from going out on June 21, 2017.

DJ playing reggae in a tree!

On this day, France celebrated “Fête de la Musique,” or “Music Day.” I couldn’t believe it – it was a whole day devoted to making music. A group of us went out to explore and we found our first venue at Parc Montsouris where a DJ was set up in a TREE playing reggae music. Afterwards, we ventured towards Denfert Rochereau, the Luxembourg Gardens, and the Latin Quarter to see tons of bands playing music wherever we turned. Now whenever I listen to music, I pay a lot of attention to each instrument/voice and their role in creating the structure and musicality of the song. So when listening to these French bands, the one instrument/voice I particularly listened for was the bass.

Taiko Drumming at Le Jardin du Luxembourg

Whether it’s the electric bass guitar of a rock band, a tuba in a wind ensemble, an upright bass in a jazz band, or the electronic 808 bass lines that can blow out your speakers heard in many chart-topping songs today, having a bass is critical when creating music. The bass lays a tonic and rhythmic foundation for the other instruments/voices to play off of. Without the bass, the music would fall apart.

Parc Montsouris

Luxembourg Gardens

To prove to you just how important the bass is, I found a study by Hove et al. (2014) that looked into how our brain detects lower musical pitches as a foundation for musical rhythm. The researchers repeatedly played low-pitched (G3) and high-pitched (B-flat4) piano tones every 500 ms, but the catch is that 10% of the time, the tone would be played 50 ms too early. Subjects were hooked up to an electroencephalogram (EEG), which detects electrical signals in your brain using metal electrodes attached to your head, and were tasked to tap their finger to the rhythm of the piano tones. With the EEG, the researchers looked for mismatch negativity (MMN) amplitudes, which are electrical responses set off by the auditory cortex (a brain region that processes auditory information) whenever it detects something unexpected when listening to a stream of sounds (Picton et al., 2000).

Electroencephalogram (EEG)

Results showed that these MMN amplitudes were greater when the subjects heard the early low-pitched tone than when they heard the early high-pitched tone. When finger tapping, subjects shifted the timing of their taps significantly more after hearing the early low-pitched tone than when the early high-pitched tone was heard. These results support the idea that: 1. our brain, at the auditory cortex, is better at processing the timing of lower-pitched tones than higher-pitched tones, and that 2. we are better at synchronizing body movements to the rhythms we hear when listening to lower-pitched tones than higher-pitched tones (Hove et al., 2014).

The Auditory Cortex

In this study, I believe it may have been noteworthy (no pun intended) to also include piano tones that are played 50 ms too late as well. This could show whether our brain can tell a difference in detecting an early or late beat in these low-pitched tones. Regardless, I really appreciated the musical application of their study. For example, they related these findings to the importance of bass notes in complex rhythms, such as ragtime piano syncopation (off-beats) or waltzes played in segments of 3 beats. This study shows us the relevance of bass in music and its importance in rhythmically keeping all the other aspects of a song together as one unit of sound. So whether it’s the music heard around every corner in Paris during “Fête de la Musique” or the heavy EDM music I just casually listen to back at home, you’ll probably see me grooving, especially to the bass of the music.

 

References:

Hove MJ, Marie C, Bruce IC, Trainer LJ (2014) Superior time perception for lower musical pitch explains why bass-ranged instruments lay down musical rhythms. PNAS 111(28): 10383-10388.

Picton TW, Alain C, Otten L, Ritter W, Achim A (2000) Mismatch negativity: Different water in the same river. Audiol Neurootol 5(3-4): 111-139.

Pictures of the DJ and drumming were personally taken.

The EEG and auditory cortex pictures are credited to Creative Commons.

 

La belle ville de Paris: Perceptions of Beauty

So far, two weeks of getting lost in the metro, enduring drastic weather changes, and having frustrating French conversations at the market have passed during our stay in Paris. From the expectation of having exact change for every monetary transaction to the snarling gazes at our (somewhat) loud group of fifteen in the metro, adapting to the social norms of the French culture has proven to be quite the challenge (I’m just glad I haven’t been pickpocketed…yet).

Arc de Triomphe

However, living in one of the world’s most beautiful cities and being surrounded by some of the most famous landmarks in the world have made it easy to forget these daunting hardships faced by our curious group of American college students. Whether it’s marveling at the size of the Eiffel Tower, walking down the Champs-Élysées with the Arc de Triomphe always in view, or even just observing the characteristically quaint Parisian architecture of all the apartment buildings, Paris always has something to offer around every corner. Thus, as a student who’s on this trip to learn more about neuroscience (and to eat lots of delicious food), I began to question myself: What makes these Parisian scenes so appealing and beautiful? What’s the neuroscience behind what we determine as beautiful? I’m hungry, where can I find me some crêpes?

Eiffel Tower

I came across a study focusing on brain systems with regards to aesthetic and perceptual judgment. The scientists who conducted this study, Ishizu and Zeki (2013), have previously shown that the experience of beauty, regardless of its source (for instance, looking at a famous art masterpiece or listening to beautifully composed music), activates an area of the medial orbitofrontal cortex (mOFC) (Ishizu and Zeki, 2011). This area of our brain is involved in the cognitive process of decision-making. Thus, judgment comes into play when you’re making these decisions.

medial orbitofrontal cortex (mOFC)

If you were shown a picture and you were told to say whether you thought it was beautiful or not, not only are you making judgements based on the picture’s aesthetics, you’re also making judgements based on its quality. So what’s the difference between the two? Let’s say you were given two paintings and you were told to determine which one you thought was more beautiful. When shown these pictures, you see that one painting (let’s say painting A) was three times the size of painting B and also seemed to appear brighter. Right off the bat, you’ve made judgements about painting A’s qualities (size and brightness). However, when you observe painting B, you notice that even though it may not be as big or as bright as painting A, you find painting B’s content to be portrayed as more aesthetically pleasing than painting A. This study aimed to figure out whether aesthetic judgements also involved the activity of the mOFC and how these two types of judgement contribute towards judging the beauty of something, like crêpes!

To test this, human volunteers (non-artists or musicians to alleviate any bias) went through two sessions: aesthetic and brightness. In each of these session, the subjects were shown a series of two paintings and were told to judge which one was more beautiful (in the aesthetic session) or brighter (in the brightness session). The researchers used functional magnetic resonance imaging, or fMRI, scans that acquired readings of blood oxygen levels in the brain. This allows researchers to see what areas of the brain are being activated when the subjects are told to judge the paintings.

Figure 6 of Ishuzu and Zeki (2013) – shows what brain areas are affected by the type of judgment (brightness or aesthetic).

Results showed that aesthetic and brightness judgments use both shared and separate brain systems. While aesthetic judgement mainly activated subcortical regions and the OFC (areas previously mentioned that were associated with beauty), brightness judgement did not activate any areas with significance compared to the areas activated by aesthetic judgment. However, both aesthetic and brightness judgement activated shared systems, mainly involving the dorsolateral prefrontal cortex (dlPFC) (involved with decision making, memory, and cognition) and bilateral anterior insula (known to be involved with many functions, including cognitive and emotional processes).

A beautiful crêpe

This new insight has led me to think about how I judge Paris’s beauty. Do I think the Eiffel Tower is beautiful, or am I just awestruck by its massive size? Do I think the Parisian architecture is beautiful, or is my familiarity to what I normally see in America causing me to think otherwise? The study mentions that further separating the processes of judgement, decision, and experience is difficult because they all use the same brain areas. Being able to understand these separate processes would allow us to really understand how this part of our brain works and finally uncover the truth as to why I find crêpes so beautiful.

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Sources:

Ishizu T, Zeki S (2011) Toward A Brain-Based Theory of Beauty. PLoS ONE 6(7):e21852.

Ishizu T, Zeki S (2013) The brain’s specialized systems for aesthetic and perceptual judgment. The European Journal of Neuroscience 37(9):1413–1420.

mOFC picture: https://commons.wikimedia.org/wiki/File:MRI_of_orbitofrontal_cortex.jpg

Arc de Triomphe, Eiffel Tower, and Crêpe pictures were personally taken.