"Are you still watching?" Observing and Explaining the Relationship between Electronic Media Use and Sleep

Summary

Sleep is key to health: the negative consequences of insufficient sleep stretch to a wide range of health issues, resulting in a reduced quality of life and increased mortality. Studies show that one in three adults is not sleeping enough and that 42% is unsatisfied with their sleep quality. The ubiquity of media in daily life has prompted researchers to investigate the contribution of electronic media use to sleep insufficiency, in particular among children and adolescents. In general, increases in media use coincide with lower sleep quality and shorter sleep. The mechanisms that underpin these associations are, however, not fully understood. This led to the inception of this dissertation.

We conducted several large-scale, cross-sectional survey studies to examine the relationship between electronic media use and sleep among adults. We operationalized sleep in two ways: one part of the dissertation focuses on sleep quality, whereas the investigates sleep behavior. Four conclusions can be drawn from the results:

We observed a negative relationship between electronic media use and indicators of sleep quality. More electronic media use before bedtime was related to a later bedtime, longer sleep latency, and more symptoms of fatigue and insomnia. These results confirm earlier findings among children and adolescents. However, we found no evidence of sleep displacement among adults, the process whereby media use reduces sleep duration which is consistently found among children and adolescents. Instead, we documented a process of time-shifting, whereby adults seem to compensate later bedtimes by getting up later, leaving sleep duration unaffected.  

The association between electronic media use – more specifically television viewing – and sleep quality can be partly explained by increased levels of arousal. Even though prior research has identified arousal as an underlying mechanism of the effects of media use on sleep, this dissertation widens the scope by looking at arousal as a cognitive-affective response to media use. In particular, we introduce arousal as a response resulting from (1) a heightened level of engagement with media and (2) a negative appraisal of media use.

The results show that electronic media use contributed to the delay of bedtime, which suggests that media use can also affect sleep behavior. Media use was not only prevalent before bedtime, but in bed as well. This observation, and the subsequent negative impact on sleep, is an important contribution to the existing literature, which has predominantly focused on what happens before bedtime. Consequently, the dissertation proposes to redefine sleep displacement as a two-step process, as media use does not only seem to contribute to the delay of bedtime, but also to the delay of sleep once in bed.

Self-control can partly explain the association between electronic media use – more specifically television viewing – and sleep behavior. Low self-control undermines the adequate regulation of television viewing, which increases the likelihood that we delay bedtime without having an intention to do so. In other words, we want to go to bed on time, but we fail to time manage our media use.

The results of this dissertation may aid in the development of recommendations and interventions. The identification of two underlying mechanisms  - arousal and self-control – provide input for the design of novel interventions to tackle the negative impact of media use on sleep outcomes. In addition to a refinement of current sleep hygiene guidelines – which have exclusively focused on what happens before bedtime – our findings may also assist in an update of current sleep behavior measures. In particular, the results imply that an accurate assessment of sleep behavior takes into account the possibility that bedtime does not necessarily equate the timing of sleep.

By indicating that electronic media use may affect both sleep quality and sleep behavior, this dissertation suggests that electronic media use may have both short-and long-term effects on sleep, and that media may play a potentially significant role in the development of chronic sleep difficulties. However, it is crucial that future research devotes attention to the causality of this issue, as it is equally possible that the relationship is reversed (i.e., sleep difficulties that relate to increased media use before bedtime), or that it is cyclical (i.e., a feedback loop where media use and sleep jointly impact each other).