Music is a fundamental attribute of the human species. Virtually all cultures, from the most primitive to the most advanced, make music. It’s been true through history, and it’s true throughout an individual’s lifespan. In tune or not, we humans sing and hum; in time or not, we clap and sway; in step or not, we dance and bounce.
The human brain and nervous system are hard-wired to distinguish music from noise and to respond to rhythm and repetition, tones and tunes. Is this a biologic accident, or does it serve a purpose? It’s not possible to say. Still, a varied group of studies suggests that music may enhance human health and performance.
Music and the brain
Like any sound, music arrives at the ear in the form of sound waves. The external ear collects sound waves, and the ear canal funnels them to the eardrum. As the waves strike the eardrum, they cause it to vibrate. The vibrations are relayed along the chain of tiny bones in the middle ear until they reach the third bone, the stapes, which connects to the cochlea.
The cochlea is a busy little world of its own. It is filled with fluid that surrounds some 10,000 to 15,000 tiny hair cells, or cilia. Vibrations of the stapes send fluid waves through the spiral-shaped cochlea. The fluid waves produce swaying movements of the hair cells. In turn, these cells release chemical neurotransmitters that activate the auditory nerve, sending miniature electric currents to the auditory cortex in the temporal lobe of the brain.
From there, things get even more complicated. Studies using MRI and positron emission tomography (PET) scans suggest that nerve networks in different parts of the brain bear primary responsibility for decoding and interpreting various properties of music. For example, a small area in the right temporal lobe is essential to perceive pitch, which forms the basis of melody (patterns of pitch over time), chords (several pitches that sound at the same time), and harmony (two or more melodies at the same time). Another nearby center is responsible for decoding timbre, the quality that allows the brain to distinguish between different instruments that are playing the same note. A different part of the brain, the cerebellum, processes rhythm, and the frontal lobes interpret the emotional content of music. And music that’s powerful enough to be “spine-tingling” can light up the brain’s “reward center,” much like pleasurable stimuli ranging from alcohol to chocolate.
Although every healthy human brain can perform all the complex tasks needed to perceive music, musicians’ brains are, so to speak, more finely attuned to these tasks. At the other end of the spectrum, patients with brain damage may display remarkable defects in musicality; the noted neurologist and writer Dr. Oliver Sacks discusses many fascinating varieties of amusia in his book Musicophilia.
The neurobiology of music is a highly specialized field. But music also has major effects on many aspects of health, ranging from memory and mood to cardiovascular function and athletic performance.
Music and the mind
The most highly publicized mental influence of music is the “Mozart effect.” Struck by the observation that many musicians have unusual mathematical ability, researchers at the University of California, Irvine, investigated how listening to music affects cognitive function in general, and spatial-temporal reasoning in particular. In their first study, they administered standard IQ test questions to three groups of college students, comparing those who had spent 10 minutes listening to a Mozart piano sonata with a group that had been listening to a relaxation tape and one that had been waiting in silence. Mozart was the winner, consistently boosting test scores. Next, the investigators checked to see if the effect was specific to classical music or if any form of music would enhance mental performance. They compared Mozart’s music with repetitive music by Philip Glass; again, Mozart seemed to help, improving spatial reasoning as measured by complex paper cutting and folding tasks and short-term memory as measured by a 16-item test.
How might music enhance cognitive performance? It’s not clear, but the researchers speculated that listening to music helps organize the firing of nerve cells in the right half of the cerebral cortex, the part of the brain responsible for higher functions. According to this construct, music — or at least some forms of music — acts as an “exercise” that warms up selected brain cells, allowing them to process information more efficiently. It’s an interesting theory, but before you rush out to stock up on recordings of Mozart’s music, you should know that even in the original research, the “Mozart effect” was modest (8 to 9 IQ points) and temporary (15 minutes). And in reviewing 16 studies of Mozart’s music and human cognitive function, a Harvard psychologist concluded that the effect was even smaller, amounting to no more than 2.1 IQ points. It’s a sour note, but it’s hardly a requiem for the theory that music may boost cognitive function. In fact, the divergent results should serve as a prelude to additional research. And even if listening to music turns out to have little long-term effect on cognition, a 2010 review reported that learning to play an instrument may enhance the brain’s ability to master tasks involving language skills, memory, and attention.