Earworms and The Brain Itch
Why Some Music Gets Stuck in Your Head
It’s happened to all of us at one time or another. We’re engaged in some mundane task or routine activity—brushing our teeth or cleaning up after an evening meal—when suddenly, a song fragment usually lasting eight or nine seconds pops into our head and then stays there, playing out in an endless loop for what seems like days. This psychological phenomenon—sometimes referred to as “stuck song syndrome” but better known as an earworm—afflicts 90 percent of us at least once a week. What’s more, “sticky music” has been recognized as a syndrome for more than a century. Germans coined the term ohrwrum more than 100 years ago. Mark Twain even described the phenomenon in a short story published in 1876 called “A Literary Nightmare.”
But what causes “sticky music,” and why does it matter? The subject has fascinated brain scientists for years because it offers a window into how the brain works. After years of research, scientists have produced a growing body of literature identifying the triggers for “involuntary musical imagery.” It’s involuntary because we’re not aware of why it occurs, and we’re not consciously trying to sing these song fragments.
Studies have found that earworm tunes have certain melodic features; for example, a faster pace that contains notes with longer durations and smaller pitch intervals might make these songs easier to sing along with. Additionally, these tunes often have particular musical shapes and contours that include simple, familiar structures. “Twinkle, Twinkle, Little Star” starts at a low pitch that then rises and finally settles back on a low note—a very common shape for a melody. There has to be a certain level of complexity present as well, with a unique interval pattern within the pitches that makes the song distinctive. Think of “In the Mood” or “My Sharona.” The melody, in other words, has to be complex enough to be interesting, but not too complicated to be remembered.
Earworm tunes are also often associated with a particular experience and its intensity, whether pleasurable or stressful. So, one might say each is directly related to a person’s psychology as well as the emotional and physical environment in which the song fragment is first heard.
Whatever the characteristics of the tune and the psychology involved, the more popular, frequently played, and recent, the more likely parts of it will end up stuck in people’s ears. In fact, the distinguished neurosurgeon and writer Oliver Sacks once wondered whether earworms were largely a product of the electronic age. We’ll never know for sure, but it’s certainly no accident that modern technology has played an enormous part in the phenomenon. Up until the late 19th century and before music could be recorded, most people had to go somewhere to hear music in person. Today, music surrounds us and can be heard on nearly any kind of device—on radios, stereos, and through headphones; in cars, airplanes, and in stores.
Apart from the musical or melodic triggers in a given song that turn it into an earworm and the technology that helps make this possible, there is the science of the brain itself. It turns out that some brains are just more susceptible to earworms than others. According to a recent study on earworms and brain structure done at Goldsmiths, University in London, the frequency of earworms is related to the thickness of the outer (cortical) layer of the brain in several of its regions, but especially the right frontal and temporal cortices. Those who were more susceptible to earworms had a thinner cortical layer in these areas, which are linked to musical perception, music imagery, and what’s called spontaneous cognition, otherwise known as daydreaming. The brain’s structure even affects the way we feel about the songs that stick in our heads.
As research on this phenomenon continues, it will provide important clues to the workings of the human brain and help scientists unlock the mysteries of human cognition. It will also help to shed light on how the brain remembers and why it retains some kinds of information but not others. After all, according to Daniel Levitin, professor of psychology and behavioral neuroscience at McGill University, the reason we get earworms in the first place is because music is an evolutionary adaptation helping us to preserve factual and emotional information in an easily memorizable medium.
Audrey Barr has a tendency to get music from the 1960s stuck in her head, but a good swim is her remedy. She lives in Brooklyn, New York.