By Emma Young
Do you listen to soft music to relax before you go to sleep? In doing so, follow the advice of all kinds of organizations, including the US National Institutes of Health and the National Sleep Foundation. That advice could be counterproductive, however, according to a new study by Michael K. Scullin and colleagues at Baylor University. The work, published in Psychological medicine, found that music before bed was linked to more insomnia – and that instrumental music is even worse than music with lyrics.
In the first study, 199 online participants living in the US reported their sleep quality, the frequency and timing of listening to music, and their beliefs about how it affected their sleep. Almost all – 87% – believed that music improved sleep, or at least didn’t interfere with it. However, the team found that more total time spent listening to music was associated with poorer sleep and daytime sleepiness. A little more than three quarters of the participants also reported frequent “catchy tunes” – a song or melody “hangs” and repeats itself in their thoughts. A quarter said they experienced it at night at least once a week, and these people were six times more likely (unsurprisingly) to report poor quality sleep. The team’s analysis revealed that targeted listening to instrumental music shortly before bedtime was associated with more sleep-related earwigs and poorer sleep quality.
The team then conducted an experimental study on 48 young adults. After arriving at the sleep laboratory at 8:45 p.m., participants went to a quiet, dimly lit bedroom, where they completed a series of questionnaires that included measurements of stress, sleep quality, and daytime sleepiness. They also had electrodes on, ready for nightly polysomnography (which recorded their brainwave activity and heart rate and breathing) and reported how relaxed, nervous, energetic, sleepy, and stressed they felt.
At 10 p.m. they were given a “break” with soft music. Half were randomly selected to hear three songs: “Don’t Stop Believin ‘”‘ by Journey, “Call Me Maybe” by Carly Rae Jepsen, and “Shake It Off” by Taylor Swift, while the other half were instrumental-only versions of them Heard the same songs (the team selected these songs because they are known to be catchy tunes and were probably very familiar to the participants)
Participants reported decreases in stress and nervousness and increased relaxation after listening to both songs, and also showed decreases in blood pressure. As earlier studies suggest, soft music before bed was actually relaxing at this time. However, a quarter of the participants woke up from their sleep with a catchy tune, and the polysomnographic data showed that instrumental versions of the songs were more likely to trigger this awakening and cause other sleep disorders, such as switching from deeper sleep to lighter sleep. Taken together, the results “provide causal evidence that instrumental music before bed affects sleep quality by creating catchy tunes,” the team writes.
The EEG data showed that the participants who woke up with a catchy tune had significantly larger “frontal slow oscillations” – a classic signature of memory consolidation during sleep. Earwig-associated slow oscillations were also observed in the auditory cortex, which processes noise. The awakening of catchy tunes seems to result from the reactivation of melodies that are heard during the day during sleep as part of the memory consolidation process. Overall data from the team suggests this is more likely to happen when the melodies are heard before bed and are instrumental.
Why purely instrumental songs should have a greater impact than music with lyrics is not clear. The three songs used in this study were chosen because they are likely to be well known. Hearing you without hearing the text may have caused the participant’s brain to add the words, increasing the chances of catching a tune. If so, all instrumental music may not have the same effect. However, the data from the first study agrees with the idea that instrumental music is generally a bigger problem.
This work, of course, has practical implications. “Just because listening to music is fun doesn’t mean that more music is always better for your health,” the team writes.
And for anyone struggling with catchy tunes at night, the researchers have a few recommendations: Limit the amount of music you listen to during the day and avoid listening to music before bed. Instead, spend maybe 5-10 minutes writing a to-do list for the next day, as previous work with Scullin has found this to help people fall asleep. If you’re having trouble sleeping, you may also want to consider digital interventions or even a rocking bed.
– bedtime music, involuntary musical images and sleep
Emma Young (@EmmaELJunge) works at BPS Biomedarticles