review: this is your brain on music

Ticket to Bonnaroo: Ouch.

Acoustic guitar: Not cheap

Audiophilic earbuds: Too much.

Figuring out why I invest so much in music: Priceless. Actually that’s not true, it was $16.00.

I love music. I munch on melodies and revel in rhythms for hours every day. I deconstruct my favorites to establish exactly which elements I most enjoy, be it the double high-hat tap in the chorus of Bloc Party’s “Banquet,” the seamless transition from voice to synthesizer in Miike Snow’s “Silvia,” or Matt Berninger’s subtle inhale after singing “losing my breath…” in “Lemonworld.” My addiction to music and the pleasure it yields overshadows the pointlessness of this analysis. Given this fact, it’s no surprise that This is Your Brain on Music was, to me, a fascinating exploration of the neuroscience behind humanity’s affinity for organized sound. The book’s content was dense and a bit repetitious, but some of the concepts were too interesting not to share.

1. Rippling waves caused by air displacement are responsible for “sound.” This sound is only perceived by organisms equipped to convert and assign meaning to the displacement. There lies the answer to that age-old question “if a tree falls in the forest…” The answer is no. With nothing around to witness it, the tree generates only the potential for sound. Hairs within our ears send signals to the auditory cortex, which converts the waves into a pitch. Different organisms translate the waves differently: when pets watch our television or listen to our music, they’re hearing something entirely different than we are.

2. One of the most important musical concepts is timbre. Loosely defined as the way something sounds, timbre refers to the metallic clink of a struck triangle or the squeal of a tenor saxophone. Sound waves actually vibrate at many frequencies that are multiples of each other, creating a fundamental tone at, say, 50 hz, and overtones at 100 hz, 150 hz, 200 hz, and so on. Each object has a unique frequency signature determined by factors like density and thickness. This signature is largely responsible for its timbre. Our brains can memorize and later identify these timbres, accounting for our ability to identify instruments and, more importantly, individual voices. Synthesizers rocked the music world by allowing the user to manually set and change frequencies, enabling them to adopt any timbre. They don’t sound perfectly identical to real instruments, however, due to variations in two more timbre components beyond frequencies—attack (the sound of the initial strike of the instrument) and flux (change in sound as a note rings).

3. A scale is composed of 12 semitones. Each of these differs in frequency from the last by 6% until, compounded by a factor of 12, the frequency doubles. Doubles or halves in frequency are heard as octaves. Intervals aurally perceived as stable, the perfect fourth and perfect fifth, have frequency ratios of 3:2 and 4:3, respectively. In contrast, the most unstable, the tritone (augmented 4^th/diminished 5^th), has a ratio of √2:1, an irrational number.

4. The brain controls everything. Dualist philosophers like Rene Descartes once believed in the segregation of “mind,” the consciousness that you are you, and “brain,” the motor that moves and controls you. This isn’t the case. Consciousness is generated by electrical impulses from neurons firing, and tweaking the brain even slightly has profound consequences. Damage to the frontal lobe causes severe changes in personality and stimulating the cerebellum can totally alter mood, even to extreme, inexplicable rage. So where does the brain show activity when listening to music? Everywhere. Rhythm (toe-tapping) is controlled by timing circuits in the cerebellum, the hippocampus and frontal lobe categorize and convert to memory new timbres and chord combinations, and the amygdala, responsible for emotional processing, shows activity. Most telling, though, is the involvement of the nucleus accumbens, the brain’s pleasure and reward system. Initial research done in 1980 showed that administration of a chemical called nalaxone removed much of subjects’ pleasure in listening to music. Here’s the kicker: nalaxone blocks the uptake of dopamine, the neurotransmitter primarily responsible for pleasure. Later research confirmed the release of dopamine during dedicated music listening. It’s the same chemical released when gamblers win a bet, chocoholics eat a Godiva bar, and heroin addicts shoot up. Music, quite literally, is an addictive drug.

5. Familiarity significantly impacts musical taste. The auditory system is one of the first sensory systems to develop in the womb, and babies begin hearing sounds (and music) roughly 5 months after conception. The brain begins forming memories of timbres, melodic contour, and chord resolution patterns. As more music is heard, processing capacities improve and music taste graduates from children’s songs with simple melodies and few chords to denser, more advanced structures. Children may love Barney’s sing-alongs, but adults find them facile and simplistic. Additionally, those raised hearing western songs featuring guitar, drums, and bass may balk when presented with middle-eastern or Asian music using different scales and instrumentation. Those native to that region, however, would feel the same listening to western music. Taste is a function of acclimation.

6. Music likely began (and continues to exist) as a means of natural selection. Dancing requires advanced motor coordination, a skill valuable for dexterity in hunting. Mastery of an instrument, in the tribal era, signified a wealth of resources so great that the musician could afford to waste time on something nonessential to survival. Also, the composition and performance of music demonstrates a degree of intelligence. Psychological studies of women revealed that during peak fertility periods, males with intellect and cunning were regarded more highly than those with resources. As hormones subsided, these preferences switched. The implication is that, on an evolutionary level, women may want a child fathered by an intellectual and raised by a provider.

I rarely read, let alone write book reviews, but I learned a great deal from this one. I must admit, though, that the link between music and mating is really, really disappointing. It makes perfect sense, but I’d like to believe that my passion for music stems from appreciation of artistic expression, not my need to flaunt intelligence for suitors. Even more troubling, this realization called into question just how much of my personality, hobbies (even blogging) and goals are dictated not by free choice, but by how likely they are to attract a mate. I had this misplaced notion of humans as dignified creatures with morals and standards that supersede those of less refined species. But the more I learn about neural function and human behavior, the more convinced I become that we’re a race of over-evolved animals clinging desperately to a misplaced notion of purpose.