Earworms: Why catchy tunes get trapped in our heads

  "Earworms", some people call them. Songs that get stuck in your head and go round and round, sometimes for days, sometimes for months. For no apparent reason you cannot help yourself from humming or singing a tune by Lady Gaga or Coldplay, or horror upon horrors, the latest American Idol reject.

To a psychologist – or at least to this psychologist – the most interesting thing about earworms is that they show a part of our mind that is clearly outside of our control. Earworms arrive without permission and refuse to leave when we tell them to. They are parasites, living in a part of our minds that rehearses sounds.

As well as containing repetition, music is also unusual among the things we regularly encounter for being so similar each time we hear it. Fences are visually repetitive, for example, but each time you see the same fence you will look at it from a different angle, or in different light. Put a song on your stereo and the sound comes out virtually identical each time. Remembering is powerfully affected by repetition, so maybe the similarity of music engraves deep grooves in our mind. Grooves in which earworms can thrive.