It’s truly annoying when an irritating song gets stuck in your head for no reason at all, but there may be nothing for it except togrin and bear it — at least until the next annoying song comes along.
According to a report in Nature, a group of scientists has figured out just what is going on when you “hear” a song without listening to any music.
What William Kelley and his colleagues did was to use magnetic resonance imaging (MRI) to look at what happens in the brain when you are “hearing” a song or some other unprompted sounds such as when you say a phone number in your head.
To date, the authors explain, the few studies that have examined the topic of auditory imagery, as that inner voice is called, have focused on what happens when someone is asked to, for example, imagine a tone. But what the authors wanted to find out is what happens when that tone just pops into your head.
So using MRI, the team asked subjects to listen to popular music which included excerpts of songs with lyrics (for example, Satisfaction by the Rolling Stones) and instrumentals that contained no lyrics (for example, the theme from The Pink Panther).
The subjects told the researchers beforehand whether or not they were familiar with a piece of music and so a unique soundtrack was created for each individual.
Then small snippets of the music (just 2 to 5 seconds each) were removed at different points during the soundtrack and replaced with silent gaps. The scientists then monitored what happened in the brain during those gaps, with songs the individual knew and those they were unfamiliar with.
All the subjects told the researchers that they ‘heard” a continuation of the familiar songs, but not of the unfamiliar songs, during the gaps in the music.
And the MRI information confirmed that subjective view: silent gaps embedded in familiar songs provoked greater neural activity in auditory association areas than did silent gaps embedded in unknown songs. This was true for gaps in songs with lyrics and without lyrics.
It also appears that lyrics play part in just which bit of the brain we use to recreate the sounds. The researchers found that when lyrics could be used to generate the missing information, reconstruction ended in auditory association areas. Gaps in instrumental pieces produced additional activity in a neighboring brain area, the primary auditory cortex, which also showed more activity for known tunes compared with unknown tunes.
The team suggests that these findings mirror the activity that occurs in the brain’s visual areas during visual imagery. In both auditory and visual reconstructions, a linguistic association (such as adding lyrics to a melody or naming the object to be visualized) assists the reconstruction process.
So the scientists argue that their findings offer a neural basis for the spontaneous and sometimes vexing experience of hearing a familiar melody in one’s head.
“Simply muting short gaps of familiar music was sufficient to trigger auditory imagery — a finding that indicates the obligatory nature of this phenomenon, ” the authors note in Nature.
So, it appears to be sad but true that you really can’t get that song out of your head.