Friday, July 2, 2010

A meeting of science and music

I have recently started reading a book called This is Your Brain on Music: the Science of a Human Obsession by Daniel J. Levitin. I have been in love with music for as long as I can remember, just as long as I have been in love with science. So when I came across a book that fused the two, I absolutely had to purchase it and moved it to the top of my 'to read' list. I have only just begun and already I am finding it to be everything I had hoped it would be and more. Having an understanding of music theory has made much of it a bit easier to digest, though even a musical layman would be able to understand what is presented as the author takes his time to explain the concepts quite well without being deprecative towards the reader. The author is both one of the more renowned musical producers alive as well as one of the leading researchers in the field of cognitive neuroscience. For anyone with a passion for music, this book is a must read. It goes about answering questions such as: what is music, does listening to music make us intrinsically smarter, when do musical preferences form, how does our brain process music, and many other questions.

But what I really wanted to mention (other then a laudatory reference to the book and a quick review) was an experiment mentioned within this tombs pages. An experiment that asked the question 'do other organisms perceive sound as we do?' as well as 'how does the brain process sound?'.

The experiment was conducted by a then graduate student by the name of Petr Janata (He is now an Associate Professor at UC Davis in the Psychology Department and at the Center for Mind and Brain). Other then being a student of biology, Petr is a lover of music. He is a pianist with a preference leaning toward rock and jazz and currently uses music as a model for a neural basis of auditory attention, imagery, and memory as well as working on the relationship between music, emotion, and memory.

The experiment revolved around a phenomena that occurs when a listener hears music with the fundamental frequency removed. Every note we hear is composed of multiple pitches. The base pitch is the 'fundamental frequency'. Often, every other pitch is an integer of the fundamental frequency, these other pitches are known as 'overtones'. An example being, if a note has a pitch of 110Hz, then the overtones will have a pitch of 220Hz, 330Hz, 440Hz, etc. When ever we hear a sound, our brains look for the fundamental frequency. It is so key to how we perceive sound that, if you were to remove the fundamental frequency from a tone, your brain would create it for you.

In Petr's experiment, he was curious as to whether other animals perceive music as we do. So he placed electrodes on the inferior colliculus (a portion of the brain responsible for auditory comprehension) of a barn owl (Tyto alba). He then proceeded to play Strauss's "The Blue Danube Waltz", but with a significant change. The fundamental frequency was removed from the piece.

So a computer recorded the firing of neurons in the brain of the barn owl as it listened to that piece of music made famous to my generation thanks to the film 2001: A Space Odyssey. After the waltz was over, Petr sent the recorded data through an amplifier and a loudspeaker. Confirming Petr Janata's suspicion and amazing everyone who was within earshot, the sound that came out was the melody of The Blue Danube Waltz, complete with its own fundamental frequency. The barn owl's brain had restored the missing pitch just like any human brain would.

This confirmed that music, the arrangement of pitches in time, was not a human invention, but something that has been with us for a very long time. Considering the last common ancestor between a human and an owl is the reptiles that divulged into the anapsids (the turtles and tortoises), diapsids (the dinosaurians and, later on, the avians), eurapsids (the line that led to the ichthyosaurs) and the synapsids (which a branch of, the therapsids, became mammals). Sound in time, music, has been a part of life, it seems, for at least many millions of years.


So it seems that my obsession with music is not only healthy, but something that is ingrained within us, coded in our deep genetic past. The experiment further proves that we are just another animal species amongst many, living on this tiny rock of ours. And that those other species, the ones that many of us look down upon, also comprehend the world around them. That they perceive it in a fashion quite similar to our own. That they hear music as we do...and their minds process it just as we do. By seeing this, there really is not much separating us from them. Though, there never was much barricading us away. We just wished it were so, to feed our egos, to make us seem more important. But by understanding our connection, we find that our importance is not lost, but strengthened, and so is the meaning behind every other living organism.


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Reference:

Daniel J. Levitin. (2006). This is Your Brain On Music: The Science of a Human Obession. London, England: Penguin Group

Janata, Petr. (August, 1994, last change April, 2010). Petr Janata's home page. http://atonal.ucdavis.edu/~petr/

University of California at Berkeley. (last change, July, 2010) One subset of Gnathostomata is Osteichthyes, bony vertebrates. http://locolobo.org/Clades2.html
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