Saturday, March 24, 2007

This is Your Brain on Music, part 1, summary

Daniel Levitin
This is Your Brain on Music

In 2006 Daniel Levitin's book This Is Your Brain On Music was published. I read about it in Salon. I don't usually take things in Salon that seriously because they're sirt if shriekingly paranoid half the time and often articulate political and social views that don't always gel. At any rate, whether or not their ideas make sense or are any good they can sometimes be an interesting read, which is really the most you can say about any magazine, and they had a review of this book that caught my attention.

Music, like almost any art, is the kind of thing where detailed study simultaneously demystifies and remystifies the nature of the art. When you figure out how to juxtapose two different chords whose roots are functionally a tri-tone apart and figure out how to do that in a piece of unabashadly tonal music it's just more fun all around than if you just stumbled on something without knowing what you're doing. Understanding how you understand music doesn't make music less fun.

It turns out there's debate as to how we understand music and what that means because there are competing explanations for why humans have music to begin with. Levitin approaches this topic from an evolutionary, socibiological angle (to simplify a bit and since he simplifies quite a few things I don't feel guilty doing to his work what he's done to the work of others, I don't think I'm really misrepresenting him).

The actual cognitive aspects of musical perception are what makes this book interesting. The first two chapters rehash so many basic points about music theory and in such a simplified way that anyone with a couple of years of music theory will find them dull. It was interesting to read that electrodes attached to the brain of a barn owl reveal that barn owls perceive rhythm in the same way we do. This simultaneously indicates that all animals have to perceive sound in real time at some comparable level but also that the governing intelligence behind perception may not strictly require sounds to be heard "as" music.

The most interesting part in the earlier chapters is that the ear itself does not do as much of the perceptual stuff as the brain. Air molecules hit the ear drum but it is the brain that grasps the distinction between discreet vibrations on the ear drum that might be the sound of my typing as I write this blog entry verses the sound of shuffling chairs in the living room upstairs where my roommates are having a meeting with some guests.

The capacity we have to perceive sound in direction is something Levitin could have explored in some more detail around chapters 3 and 4. That we can perceive in 360 degrees how we are immersed in a world full of sounds fascinates me but I guess I'll have to go for scholarly research on that rather than the pop science level Levitin is writing at, which is still interesting and informative. His explanation of how we learn to ignnore steady sounds like the sound of rain outside or the sound of a washing machine is a great explanation for how our alertness to sound connects to the need to be aware of dangers and of causal relationships between sound X and threat Y.

The book gets interesting for me as a composer around chapter 4 dealing with how we anticipate and perceive musical form. He uses language as a springboard and describes how we can recognize words as words despite constant variations in the lettering, font style, font size, the font itself. It's on page 113 for those who have read the book.
Here is an approximation of the effect Levitin uses but compressed into the first part of the sentence. Despite constant shifts in the font, font size, lettering style, and even the color of the letters you can still read the first four words of the preceding sentence because your brain has trained itself (or been trained by socialization, too) to understand that what I just wrote earlier is a comprehensible sentence. Levitin's example is on page 113 of his book, for those of you who have it.

Well, the same cognitive process that allowed you to read that sentence in the previous paragraph is what allows you to perceive musical form and recognize a melody despite a series of drastic transformations. Even if a tune is played at half speed or double time; transposed into any key other than its originalkey; even if the melody is transformed by means of modal mutation from major into parallel minor or from the dorian mode to modern natural minor; even through all of this you can recognize a tune. We know Greensleeves (i.e. "What Child is This?") whether it's played in the original dorian form or in the modern minor form because the melodic contours and rhythms remain unchanged despite modal mutation. Levitin doesn't flesh this out but he notes that perception of musical form tends to display activity in the left frontal lobe of the brain, traditionally associated with intellectual or abstract perception.

But this, too, may be simplifying a bit because we have been able to learn that perceiving music activates a whole range of areas in the brain, including lower segments of the brain associated with autonomic responses and emotion. Music moves us, obviously, but to perceive the emotional content of music we have to grasp its form and so a truly affecting piece of music will engage, at the risk of overstating Levitin's case, our whole brain and not just parts of it. What we have been discovering through research is that the left brain is involved in perceiving musical structure and that these regions are also involved in understanding sign language or any structure that must be conveyed over time (page 127-128). But perceiving musical form requires both sides of the brain rather than just the left side which is all that is in use for the perception of language structured over time.

The question naturally comes up, why? For something that seems to have little practical value like music the way we experience it as background sound in a shopping mall; or listening to some jazz masterpiece reduced to music you listen to while you're on hold; or the set list at your favorite band's concert in your town; why is it that music affects is so? Why is it that people can sing from memory songs they heard twenty years ago?

An interesting partial explanation for this that Levitin offers along the way is that in adolescence the brain is closing up its soon-to-be complete set of neural networks for perception. The way my brother would put it is that it's medical/scientific proof that people decide rock music is dead once they have grown up and that the new stuff has no soul or is crap. What has changed is not really musical style per se but the perceiving brain. The brain gets gone making its set of ocnnections and unless people continually seek out new styles of music (by new I mean styles that really are different from what they like, not merely finding new variations on a sound in which they've comfortably found their style-listening rut) the brain hits an end point, so to speak.

Unsurprisingly a crucial element in musical structural perception involves memory and it's in chapter 5 that Levitin has his most interesting material. Levitin introduces, in chapter 5 the debate between two theories of memory. One theory has held that memory functions as a record-keeping function, comparable to a VCR tape; while the other theory holds that memory allows us to retain relational observations without necessarily retaining all the details about the things we remember. It doesn't take long to see how both theories fail due to reductivism and Levitin spends quite a bit of time in chapter 5 explaining how each theory hit roadblocks in lab research in the 1990s. A theory that is now getting preference is the proposal that memory is connected to cues and that if a person is presented with the right series of cues for memory that they will remember something. This accords with common sense and the anecdotal experience of quite possibly every human on the face of the earth!

It also explains why people can remember things with a high degree of accuracy in some cases but not in others, and why people with brain damage can be incapable of remembering some things accurately. But more to the point for the sake of this blog, it demonstrates that memory and perception turn out to overlap when it comes to how we perceive musical form. We simultaneously construct or infer a musical form from a song as we're listening to it, or any music we have heard before or never heard before. Hindemith explained this in A Composer's World fifty years ago saying that if we hear a piece of music and our minds can't get around the form presented to us our reaction is bewilderment or amusement.

Between the summaries of Hindemith and Levitin in their respective books it's easy to suggest that memory is vital to the perception of musical form. If a form is too simple we find it dull and if it is too complex we find it infuriating or frustrating or simply puzzling. Our capacity to perceive musical form is mediated by how our memory developes. This is not a point Levitin necessarily makes, or makes a primary concern in his book, though.

I'm going to skip the content of the other chapters as they are sort of interesting but not so interesting I want to write an even longer blog entry than I planned to write. Suffice it to say that research suggests that there are no prodigies on the basis of "talent" so much as a vast amount of practice and training. As Hilary Hahn has said in interviews, she was never a child prodigy, just someone who practiced a lot.

Levitin spends his last chapters attempting to sort out what purpose music serves. A number of scientists have dismissed music as nothing more than aural cheesecake, some useless by-product of evolutionary adaptation. Levitin refuses to concede this particular point and attempts to explain music on other grounds. There are no cultures that have no music so music can't be dismissed as aural cheesecake if every culture has it. And if it is merely the by-product of evolutionary adaptations what adaptations were those? Levitin argues that musical ability is a form of sexual selection. Any ancient human from fifty centuries ago who had the leisure time to sing and dance was advertising to prospective mates that he had the time, health, mental ability, and will to sire offspring and, perhaps more importantly, enough time left over to RAISE those kids. Levitin argues that this means that music is not useless since it seems to be one of the main means for a man to attract a woman. Considering how many songs over the millenia are love songs it's pretty hard to ignore Levitin's point. Levitin also notes briefly that in every culture available for study music and dance are constantly linked.

Scientists who think that music is just useless sound probably haven't examined the nature of memory enough. Why is it that so many children learn the alphabet through song? Scientists who think music serves no purpose might want to consider whether something is lost if they go on a date and there's no music anywhere. It seems to have a history of setting a mood.

So this is a basic run-down on the more interesting ideas in Levitin's book. I think it's a good summary but some questions seem to linger. Certainly I can tell you conservative Christians who aren't inclined to assume a Darwinian explanation won't exactly dig Levitin's assumptions about music as an evolutionary development and may not buy his attempt to explain musical idioms in human cultures as chiefly being a form of sexual selection. But interacting with Levitins ideas and study and the way this may be read in interaction with biblical literature is something I will set off in another post.


Anonymous said...

Nice blog! You raise some great points of discussion. I had to read Levitin's book for an appreciation of music class and I found it to be just as interesting.

Anonymous said...

it would be great if you could post something about the relation between academics and music. It seems like you know alot about this stuff and I am a composer too. I have a research paper due and need some help.

Wenatchee the Hatchet said...

What kind of relationship between academics and music do you have in mind? I can post something about academics in music in a bit since I've got some time on my hands but I'd be interested in finding out what relationships you have in mind between academics and music.