A little over 15 years ago, I was a memory researcher with interests in how auditory distraction affects immediate memory. It’s well-known that playing sound – including music – in the background has a large, detrimental effect on immediate verbal memory, and this has been replicated multiple times. Although there are individual differences, which are not well-understood, people’s awareness of their own susceptibility is not great (so if you think “that wouldn’t happen to me” you might well be wrong). When I started to read speculations online and in popular science books about inner music – or earworms (the term was not, at that time, as widespread – at least in the UK – as subsequently) I became interested in the possibility that there might be distracting effects of earworms. One study had already shown that if you punctuated music listening with periods of silence auditory cortex remained active during those periods as people “heard” the music that wasn’t there. At about the same time I was talking to a clinical colleague, Tim Williams, who worked with clients with Obsessive–Compulsive Disorders. He had realised rather belatedly that he had no idea whether the example he used with his clients for years of a non-pathological, everyday form of obsessive thought – a song that gets stuck in one’s head – was either as untroubling or as everyday as he’d always assumed. This was the basis of our first paper, in which we reported that although some people surveyed found earworms troubling, many people rather enjoyed it and almost no one reported finding it disruptive in any way (their immediate memory must have seemed fine!)
Despite this, I persisted in assuming that songs mostly stuck in the head if they were unwanted (and Google image searches for the term “earworm” show that the internet largely agreed with me). To investigate this, my research at this time mostly involved playing songs to people and then asking them to try not to think of the song they had just heard – a task which most people found impossible. I also assumed that earworms basically consist of musical memories of the song concerned, the kind of thing that might easily be disturbed by things that also disrupt immediate memory. For example, chewing gum (vigorously!) prevents subvocal rehearsal of verbal material, and thereby reduces immediate memory for sequences of words. Possibly my most infamous paper was the 2015 report of three experiments which showed the same sort of effect on (unwanted) earworms. People trying not to think about – and, in particular, “hear” – music that had just been played to them were more successful at doing so when chewing gum. This provided apparent confirmation that earworms are supported by immediate memory processes: Chewing gum interferes with immediate verbal memory and it also interferes with earworms. Could it be that they are susceptible because both are reliant upon the same immediate memory processes, processes which don’t work well if you have to chew gum at the same time?
Missing from this story is any indication that the earworms themselves interfere with immediate memory. Nobody reported finding this to be particularly the case in our first study (but people’s judgements of their own distractibility can be unreliable) and I hadn’t at this point provided experimental evidence to show any such effect. The necessary evidence was not long coming from elsewhere though. Two reports from a lab in Australia showed that music disrupted immediate memory when played during a memory task (not very surprising, we knew this to be the case) but also, of more interest, “catchy” tunes continued to show this effect, albeit reduced, when the memory task didn’t even begin until after the music had stopped. Initial results from my own lab also replicate this general pattern. This is interesting because in this respect music is unlike other forms of auditory distraction. If you play speech during a memory task you observe poorer memory but if you stop playing the speech immediately before the memory task starts then there is no disruption. If music (and earworms) acted like this, then that would answer my original question in the negative – no, earworms are not distracting. Since this is not the case, then we have to ask what it is that makes music different, and enables its influence (positive or negative) to spread forward over time.
Phil Beaman