Maybe it's "Don't Worry, Be Happy," or perhaps it's "I Will Survive" that's been playing on an unending loop in your head today. These songs made a recent list of the most common earworms a somewhat gross term that refers to songs that get stuck in your brain.
Psychology researchers now have some clues as to why some songs get so much air-time in our craniums.
Earworms typically develop when you've heard a song a great many times, said Andreane McNally-Gagnon, who researches earworms at the University of Montréal. People infected with an earworm did not necessarily hear the song recently it could have been months or years in the past, McNally-Gagnon said, but at some point, it was played over and over .
This may explain why classical musicians typically have the songs they practice stuck in their heads, but for the rest of us, pop songs that get frequent play on the radio are the ones that become earworms.
What you're doing also affects your chances of picking up an earworm. Most people are doing something that is somewhat routine or mindless when an earworm strikes.
"They might be doing household chores, taking a shower or waiting for a bus," McNally-Gagnon said. "Their mind is not occupied by anything."
As a psychologist, McNally-Gagnon is interested in what purpose earworms might serve. In her work, she found that people are more likely to report feeling positive emotions after an earworm has taken hold than they were before it struck.
"A function of earworms could be emotional regulation," she said.
And research into earworms may provide clues to other aspects of our memories. In her study, McNally-Gagnon asked people to sing their earworms. Surprisingly, they very closely matched the original song in pitch, key and pacing, she said.
For a long time, it was thought that people kept only a representative memory of a song in their head, and so when asked to sing it, they might sing it in a different key or at a different speed than the original. But McNally-Gagnon's research shows that songs, like visual memories, are absolute, meaning that the brain holds all of the details of the song's notes and phrasing.
The next step in her research, McNally-Gagnon said, would be to use brain imaging, such as functional magnetic resonance imaging (fMRI), to study the regions of the brain affected by earworms. But to do this, she first needs a reliable way to induce an earworm, so that people lying in brain-scanning equipment can be made to have one.
But for many people, finding ways to purposefully induce an earworm are the opposite of what they would like scientists to be doing. Unfortunately, no research has yet shown a reliable way to get an earworm out of your head either, McNally-Gagnon said.