Browsing by Subject "vuorokausirytmi"

Objectives. Over the last few decades, the usage of various digital devices has increased significantly. As people spend time on digital media especially in the evenings before bedtime, there has been a growing interest in researching the potential effects of digital media usage on sleep. The association between digital media usage and negative sleep outcomes can be explained by three different mechanisms: circadian effects of exposure to light from screens, stimulation from media content, and displacement of time spent sleeping by time spent using devices. The objective of this thesis was to review recent randomized controlled experiments regarding the effects of pre-sleep digital media usage on sleep and compare their study designs and results. Methods. Experimental studies were searched on PubMed and Ovid Mediline databases using the terms digital media, electronic media, screen light, blue light and sleep. Seven randomized controlled experiments published within the last five years were selected. All the studies had controlled the use of digital media and used both subjective and objective sleep measures. Results and conclusions. Most of the studies indicated that the pre-sleep usage of digital media has a negative effect on sleep. There were associations between the usage of digital media and sleep architecture, sleep onset latency, suppression of melatonin secretion and subjective sleepiness. In addition, each of the three mechanisms were supported by the studies. However, there were notable differences in the study designs between the studies, which made it difficult to assess the significance of the individual factors. There is a need for laboratory experiments with larger sample sizes as well as real-life studies to increase ecological validity. This would help specify recommendations regarding the use of digital media in order to improve human health and wellbeing.