John Medina's Brain Rules

Entry 049: As the Worm Turns

I’m about to ruin my whole day, and I’m going to do it by reciting a phone number. Maybe this recitation will ruin your day too. If so, I’d like to apologize in advance.  

That number is 867-5309, which is now rattling around my brain like some trapped rat.

The reason for this auditory ensnarement is not because the digits are magically memorable. It’s because of a 1981 smash hit by Tommy Tutone, a 4-minute song that mentions those numbers a whopping 29 times. Once I’ve heard the digits, I can’t get evict the song from my head. Day ruined, thank you.

And I’m not alone. More than 90% of us report experiencing what is sometimes called an “earworm.” Researchers term it INMI, short for Involuntary Musical Imagery. Their investigations reveal that INMIs have several common characteristics.

#1) The music cycles over and over again, even if you don’t want it to.

#2) The repetitions usually involve only small fragments of larger musical works. Typical duration is three or four bars.

#3) The repetition cycle lasts for varying periods of time. It can be hours, days or even months. 

And maybe one last thing: they are almost universally held to be annoying.

THE NEURAL ORGIN STORY

What do we know about the neurobiology of these unwanted musical guests? How might that relate to our general discussion of musical processing?

Frustratingly, we have no idea what earworms are, why they persist, or why some tunes incite the phenomenon and others don’t.

But there are some tantalizing hints.

One hint is neuroanatomical. Using non-invasive imaging (fMRI) experimenters had willing subjects hear portions of well-known “catchy” tunes while examining their brain activity. Then, still observing their brains, they shut off the music and had the subjects imagine the next parts. “We found that the auditory cortex that is active when you’re actually listening to a song was reactivated when you just imagine hearing the song,” said lead researcher David Kraemer. As if the brain had some internal orchestra, which could be turned on or off.

Except if the music is an earworm.

Evidence suggests that the brain’s working memory - specifically a device called the “phonological loop”- may be the culprit. Working memory is a cognitive processor that stores information in temporary buffers. These buffers are composed of several minor gadgets, one of which processes short-term auditory experiences. The phonological loop is one of these minor gadgets (it is composed of circuitry with recursive rehearsal characteristics). The earworm phenomenon may simply be a melody that can affect this loop, causing it to cycle on auto-repeat. Endlessly.

While these ideas are chock full of testable hypotheses, they are not fully explanatory. It will thus be a while before we absolutely know why some songs become earworms and some don’t. Why, for some of you dear readers, asking the question “Do you like piña colada?” will ruin your whole day, no phone number in sight. And for others, you won’t even know what I’m talking about.

REFERENCES

Arthur, C. "Why Do Songs Get “Stuck in Our Heads”? Towards a Theory for Explaining Earworms." Music & Science 6 (2023): 1-15.

Killingly, C. et al "Singing in the Brain: Investigating the Cognitive Basis of Earworms." Music Perception 38, no. 5 (2021): 456-72.

Scullin, M.K. et al "Involuntary Musical Imagery, and Sleep." Psych Sci 32, no. 7 (2021): 985-97.