"When we listen to a song, it triggers a part of the brain called the auditory cortex. Researchers at Dartmouth University found that when they played part of a familiar song to research subjects, the participants' auditory cortex automatically filled in the rest -- in other words, their brains kept "singing" long after the song had ended. The only way to "scratch" brain itch is to repeat the song over and over in your mind. Unfortunately, like with mosquito bites, the more you scratch the more you itch, and so on until you're stuck in an unending song cycle.
There are many other theories about why songs get stuck in our heads. Some researchers say stuck songs are like thoughts we're trying to suppress. The harder we try not to think about them, the more we can't help it. Other experts claim that earworms are simply a way to keep the brain busy when it's idling [source: University of Cincinnati]. Just as there are many theories, there are many names for the phenomenon. It's been called everything from "repetunitis" to "melodymania."
So why do some songs get stuck in our heads and not others?"
James Kellaris, a marketing professor at the University of Cincinnati College of Business Administration, has done research on earworms and brain itch, and he's found that as many as 99 percent of us have fallen prey to them at one time or another [source: BBC News]. Kellaris says women, musicians and people who are neurotic, tired or stressed are most prone to earworm attacks. With musicians, it makes sense because they're listening to music continuously, but Kellaris isn't sure why women are more susceptible to earworms.
Researchers also aren't sure why some songs are more likely to get stuck in our heads than others, but everyone has their own tunes that drive them crazy. Often the songs have a simple, upbeat melody; catchy, repetitive lyrics; and a surprise such as an extra beat or unusual rhythm -- the same factors that made the songs or jingles popular in the first place (like the Chili's, "I want my baby back baby back baby back ribs" jingle, which made Kellaris' list of the most insidiously "stuck" songs).
Most people (74 percent) get caught up on songs with lyrics, but commercial jingles (15 percent) and instrumental songs (11 percent) can also be hard to shake [source: DeNoon]. What makes us groan is cause for celebration to record companies and advertisers, who are thrilled when people can't get their songs and jingles out of their heads."
