On Thursday 20 February at 14:00, Rebecca Jane Scarratt defends her PhD dissertation entitled "Global and individual effects of music on relaxation and sleep". 

In an age of digitalisation, we have a thousand music pieces at our fingertips. Out of seemingly endless possibilities, how do we choose what music to listen to? Music can temporarily change certain aspects of our body, like stress levels and emotions. Therefore, it is important that we understand better how music is used in everyday life. For example, listening to workout playlists can increase heart rate and make the listener feel more energised. The opposite is also true: listening to calm music can decrease heart rate and feel more relaxed. This dissertation focuses on how music is used for sleep and relaxation.

Through various methods, this project investigates both how music is used for sleep on a global level and how individual factors like familiarity and liking influence music perception. The main findings are that overall calm, soft and slow music is the most used for sleep, although many individuals use music with opposite music for sleep. Futhermore, music that is familiar and liked by the listener is preferred for sleep and leads to higher levels of relaxation. However, some individuals respond differently to music and, in fact, some are more relaxed when listening to music they do know, regardless of the musical features and some are more relaxed when listening to soft, calm music, regardless of whether they know or like it.

The project's findings also suggest that the music that individuals use might depend on why they are using it. For example, soft and calm music might be most appropriate for relaxation but more energetic music might work better to  distract from loud neighbours or loud thoughts.

Finally, this project suggests a distinction between cognitive reactions to music and felt responses to music. In the former, a listener will judge a piece of music based on their prior knowledge, preconceptions, and analytical thinking. In the latter, a listener will respond to the music with their bodies without too much thinking. This dissertation's findings suggest that these are separate processes. This brings into question methodologies asking participants to judge or express opinions on music and rather encourages methods where participants rate how they are feeling or where their bodily reactions are directly measured.

Overall, this dissertation advances our understanding of the everyday use of music for sleep and relaxation and brings nuance to the discussion about how to consider individual differences in music research.

The defence is public and takes place in auditorium 1252-310 (Jeppe Vontilius) at Søauditorierne, Aarhus University and on Zoom. (please contact Hella Kastbjerg at hella.kastbjerg@clin.au.dk to obtain the Zoom link).

After the defense, Center for Music in the Brain will host a small reception in the Pavilion in Building 1710.