Sleep Tight, Don’t Let the Earworms Bite!
Everyone has had a song stuck in their head at some point regardless of favorite genres and how much they listen to music. With the evolution of the internet and the popularization of music streaming, the ability to listen to music has never been more accessible. Not every song we listen to will end up as an earworm, but a study conducted by Michael Scullin, Chenlu Gao, and Paul Fillmore at Baylor University shows the the more music we listen to the more likely one will end up on repeat in our heads (Scullin et al 2021).
As music has evolved over the years, the likelihood of hearing an earworm inducing song has increased. Songs that are repetitive with fast tempos are more likely to induce an earworm, especially in people who frequently listen to music (Jakubowski et al., 2017). It is also a commonly held assumption that listening to music will help you sleep at night. Listening to calming music before going to bed is a common practice among many (Trahan et al., 2018). But some studies have shown that this may not be effective in granting a good night’s sleep. Regarding nighttime earworms, there tends to be two camps of belief: One says that these small segments of songs can be distracting in a pleasant manner that helps one fall asleep and the other being that earworms are a nuisance that keep you awake. The present paper investigates the presence of earworms, also referred to as involuntary musical imagery, and how it relates to factors that affect sleep using three studies.
The first study investigated music listening habits and sleep quality using a series of questionnaires. This was a study that did not decide to alter anything, but rather look at self reported data in order to gain an understanding of people’s perceptions of nighttime earworms in the real world. The Involuntary Musical Imagery Scale was used to look into the presence of earworms, this was used to determine how people perceived getting a song stuck in their head: annoying or soothing? 77% of participants reported frequent earworms, many of whom said they occurred during sleep related times.
The figure above looks at relating Sleep-Related Earworm Frequency with different factors. Overall one can see that increased frequencies were associated with worsened sleep quality, daytime sleepiness, and insomnia. Additionally, Figure a shows that listening to greater amounts of music increased the risk of “contracting” an earworm. This study had a relatively large sample size of 209 people. From this data, the investigatory team could conclude that the increased presence of earworms was associated with worse sleep. But now the question: what kinds of music can induce nighttime earworms?
The second study conducted by the team at Baylor looked at manipulating variables to try to find potential factors affecting what becomes a nighttime earworm. Participants were played popular songs before sleeping, these songs were either Don’t Stop Believin by Journey, Call Me Maybe by Carly Rae Jepsen, and Shake it Off by Taylor Swift. Half of the time, participants listened to instrumental versions of these songs in order to investigate if lyrics were a deciding factor in creating an earworm. After waking up, participants were asked if they had a melody, sound, or song stuck in their head. While sleeping, EEG data was collected measuring the brain’s electrical activity. Scientists later used this data to analyze potential areas of the brain involved in earworm activation.
The figures above detail the data collected in Study 2. Covariate-Adjusted Sleep Efficiency (leftmost graphs) is just a measure of how well someone was perceived to have slept based on polysomnography and the Pittsburgh Sleep Sleep Quality Index (PSQI). The PSQI analyzes seven components of a participants sleep such as duration, disturbances, onset latency, etc. to then determine an overall score. Polysomnography is a practice that monitors one’s sleep cycles using EEG, it is frequently used for diagnosis of sleep related disorders like sleep apnea and narcolepsy. In Figures B and C, lyrical music (blue bars) is presented as more efficient than instrumental. Overall they fell asleep faster and had better PSQI scores. Figures e-g all present evidence that the presence of an earworm causes worse sleep including taking longer to fall asleep and waking up more throughout the night. Nighttime music regardless of containing lyrics increased the presence of earworms. However, instrumental music did produce slightly more earworms than the music that contained lyrics. Overall these earworms worsened sleep quality.
The third study looked to analyze the data collected from Study 2 in order to answer the question of why and/or how earworms persist at night given that sleep is a long period of time where someone is not receiving any musical input that results in brain activity to process it. As previously mentioned, the EEG data collected was analyzed to investigate potential localization. There was increased left temporal activity in the brain with the presence of earworms. The left temporal area has a known role in the learning and memory processes involved in verbal information. This may reflect the memory consolidation and processing of pre-sleep music, as these are known sleep related activity for the brain (Klinzing et al 2019).
Figure C is a heatmap that shows the distribution of electrical activity across the brain at a given time. In this case, the heatmaps compare when the participant was asleep (sleep-related time point) to when they woke up in the morning and reported whether or not they were experiencing an earworm (control time point). With earworms present, there are large positives in the fronto-temporal regions as seen in red. This same area is activated during the control time point. While there is still activation in these areas in populations of participants who reported not experiencing earworms, the activation level is much higher in those that had them.
From the first study, survey data suggested that overall people find nighttime earworms more irritating than those that occur during the day as nighttime occurrences disrupt sleep. In the second study, 1/4 of participants woke up with an earworm. It is also worth noting that participants were not exposed to music for 8 hours leading up to the study. The third study offered a neural explanation for where in the brain earworm processing occurs. It was concluded that musical processing is continued during sleep and that the type, duration, and timing of the music listened to all influence sleep outcomes. Those who dream vividly frequently know that the brain does not stop working even when we sleep. People may believe that listening to music may help them fall asleep, but this study provides evidence that a catchy lullaby might not be the best idea when it comes to a nighttime routine.
References
Jakubowski K., Finkel S., Stewart L., Müllensiefen D. (2017). Dissecting an earworm: Melodic features and song popularity predict involuntary musical imagery. Psychology of Aesthetics, Creativity, and the Arts, 11(2), 122–135. 10.1037/aca0000090
Klinzing, J.G., Niethard, N. & Born, J. Mechanisms of systems memory consolidation during sleep. Nat Neurosci 22, 1598–1610 (2019). https://doi.org/10.1038/s41593-019-0467-3
Scullin, M. K., Gao, C., & Fillmore, P. (2021). Bedtime Music, Involuntary Musical Imagery, and Sleep. Psychological science, 32(7), 985–997. https://doi.org/10.1177/0956797621989724
Trahan T., Durrant S. J., Müllensiefen D., Williamson V. J. (2018). The music that helps people sleep and the reasons they believe it works: A mixed methods analysis of online survey reports. PLOS ONE, 13(11), Article e0206531. 10.1371/journal.pone.0206531
