Revisiting - This is Your Brain on Music

I read "This is Your Brain on Music" by Daniel J. Levitin at the beginning of the summer, before I started this book blog technique. Overall, I found the prose unorganized and tangential at times (so I wish I did use the blog), but there were a couple of points worth remembering. I'm reading the last chapter to freshen up on some of the major ideas.

Some cognitive scientists believe that music is nothing more than a "spandrel". This is a term borrowed from architecture meaning a by-product of design. The curved surface between four arches is a spandrel, not planned by the designer who intended to simply have four arches, but the space gave rise to beautiful artwork. Similarly, music has been a parasite on the linguistic reward circuit. There has been an adaptive advantage to being about to discern rhythm, pitch and timber and there has evolved reward circuit in understanding these auditory variables to positively reinforce the learning of language. Music as simply hijacked this reward circuit (similar to cheesecake being delicious with it's fat and sugar content: although it is nutritionally backrupt, fats and sugars were rare as hunter-gatherers and a reward circuit evolved to reinforce the consumption of them).

Levitin does not subscribe to the "auditory cheesecake" argument. Instead, he agrees with Darwin's early theories that music/dance is tied to sexual selection. Much like the songbirds, males who've appropriated excess resources can devote them to higher mental abilities, such as creating music (music may be a signal of proper mental development). Dancing may also be a kind of stamina selection and general creativity may be a reliable signal of ingenuity and planning (similar to Blackmore's meme-gene coevolution). If music was just hi-jacking linguistics and was non-adaptive why would it persist in so many cultures through most of human history?

One thing that has always stuck with me has been Levitin's discussion of rhythm. He used an example of a mouse and the wind blowing a branch against a tree above his burrow. At first, the noise will startle the mouse, causing anxiety. If the knocking continues at predictable intervals, the mouse's brain will be able to predict the noise and acclimate to this "proto-rhythm", releasing endorphins to ease anxiety. Perhaps this is the basis of rhythm appreciation in humans: being able to predict a rhythm causes the brain to either relax or otherwise generally "enjoy" being successful at predicting rhythm. Secondly, should the mouse brain encounter sounds that are dramatically different than the regular rhythm of the stick, a drastic change in neurochemistry will trigger more anxiety to prepare to flee. In humans, culture as entrained us to expect these "hiccups" in rhythmic music, to the point where perhaps even more rewarding neurochemistry results from breaks in rhythms, unexpected movements or anything to add to an otherwise boring rhythm.