Can't get you out of my head – the science of earworms
Earworms are those catchy/irritating songs that get stuck in your head, but why are certain tunes so impossible to erase from your mind?
The dead of night was upon Barry Murray. The sports nutritionist and ultra-marathoner had been running for 18 hours, give or take. Right now, he was experiencing one of his earworms – tunes that would play over and over in the jukebox of his mind. Mos Def’s Ms Fat Booty was currently giving him a lift, driving him through the difficult miles.
In previous races, Use Me by Bill Withers had helped him along. “That’s the song that rings in my head,” explains Murray, who insists he never eats breakfast before racing. “It has done so for a few years now, during every ultra I have run.”
While the mental effort required to run 200km across the trails and mountain passes of County Kerry is unimaginable to most, we’re all familiar with a song that gets stuck in your head – whether it’s helpful, or just plain annoying. As many as 90 per cent of us, according to estimates, suffer from an earworm (aka brainworm, sticky music, or stuck-song syndrome) at least once a week.
Murray went on to win the Kerry Way Ultra, with a time of 26 hours and 36 minutes. His story suggests there might be a point to these musical intrusions. Perhaps, though, they’re just by-products of ordinary thought processes. This is one of the puzzles that Dr Lauren Stewart, a psychologist at Goldsmiths, University of London, is trying to solve. Stewart and her team in the Music, Mind and Brain Lab study ‘involuntary musical imagery’ – earworms, to you and me. So what have they discovered?
Some of the team’s first data came via a link with Shaun Keaveny’s BBC 6 Music breakfast radio show. “I heard their feature called Earworms,” remembers Stewart. “They got people to text in with whatever tune they had going around in their head. So I contacted the show and asked if they could share some of their data with us.”
The show sent earworms from thousands of listeners. More than 300 of them had also described how their earworms started, providing some of the data for a 2012 study on earworm triggers. No surprise that the most common trigger was listening to the very song that then got stuck.
But people also connected songs to particular words, situations and even well-known personalities. One listener, for example, described hearing This Charming Man by The Smiths every time David Cameron appeared on the TV.
The sight of David Cameron triggers This Charming Man by The Smiths in one earworm sufferer
Since then, Stewart’s group has delved further into why and how songs get stuck in our heads, and tried to understand why some people experience earworms more frequently than others. One theory, backed up by the results of one of their surveys, suggests that people with obsessive-compulsive personality types may be more susceptible to earworms. The team also has found that non-musicians seem to be just as likely as musicians to pick up earworms.
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Surprising, perhaps, but neuroscientist Dr Steven Brown at McMaster University in Ontario believes the same is true of those who experience the phenomenon of what he calls ‘perpetual music track’ – a kind of extreme earworm syndrome.
Brown himself is a pianist and has had segments of music looping in his head on a near-constant basis for as long as he can remember. Around a decade ago, he decided to conduct a self-analysis, which was published in the Journal Of Consciousness Studies. Since he published it, he’s received emails from around another 70 people with similar symptoms. But there’s no common thread, he says. “I thought it was going to be limited to people who actually work with music but it’s quite diverse. I mean, there are people like me and there are also people who say they have no exposure beyond just listening to music passively. So I don’t see any trends yet, whether for gender, age, experience or the like.”
Last year Stewart and her colleagues published the first scientific study of links between brain structures and earworms. They quizzed 44 people about their earworm experiences, then put them in a brain scanner. The results showed differences in grey matter thickness in certain regions of the brain, correlating to how often people got music stuck in their heads, as well as how problematic or annoying they found the music.
All this suggests that everyone experiences earworms or musical imagery in different ways, but that what causes these differences may not be obvious without probing deep inside the human brain.
What really intrigues Stewart is the idea that earworms could actually be good for us. Her working hypothesis is that earworms and other spontaneous thoughts could play a key role in stabilising consciousness.
“I like to think of it as a homeostatic [regulatory] function. If your consciousness slips too low, you’re in all sorts of trouble because you’re not vigilant to the dangers around you,” she explains, referring to Oliver Sacks’ near-death experience on a mountain. “So these internal thoughts might provide enough stimulation so that you’re maintaining an optimal level of vigilance.”
The theory is partly supported by another 2015 study from the Goldsmiths group that shows how the tempo of internal tunes complements our mood or arousal level. Each volunteer was asked to wear an accelerometer on their wrist for four days and to tap to the beat of their earworms on their leg. The accelerometers would record the taps. For every earworm, the participants also noted down the kind of mood they were in – upbeat, say, or a bit sluggish. Overall, there was a link between people’s states of arousal and the tempo of their earworms. As Stewart explains, “It’s not random – the songs you get depend on your internal state.” So whether it’s the state to the song or the song to the state, there’s some sort of matching process going on.
As you can imagine our brains were plagued while researching this feature – here are some of the culprits…
For Stewart, earworms are a model for mind-wandering more generally, and this most recent study suggests spontaneous thoughts while the mind is wandering may help to balance arousal levels. But is there any wider support for such a brain-balancing role?
Dr Jonathan Smallwood, a psychologist and mind-wandering expert based at the University of York, thinks there could be something in it, albeit in a slightly different sense. He cites evidence that shows people have more spontaneous thoughts when their environment is uninteresting or demands little attention.
“Under these situations, people often spontaneously devote conscious attention to other matters, such as events in their future,” he says. “This implies that people use their idle moments to make progress on goals, which is a bit like a homeostatic function.”
Make it stop!
Whether involuntary musical imagery has a helpful role to play or not, how we perceive it seems to be a very personal matter. Brown has learned to live with his internal music but claims that many of those who have written him emails about their own just want him to make the music stop.
Similarly, in the course of her research, Stewart has come across plenty of people who are plagued by their earworms, like the woman who said that the theme tune from the 1980s cartoon DuckTales was driving her mad. Yet her team’s survey results also suggest that some people find earworms are useful for completing particular tasks. Perhaps Barry Murray is just one of those people.