Several previous experimental studies produced inconsistent results with regard to the impact of nighttime videogame playing on sleep latency (how long it takes one to fall asleep). A study by Dworak and colleagues found an average increase in sleep onset latency to be about 22 minutes following a 60 minute videogame playing experience between 6:00 and 7:00 pm as compared to a control condition in which videogames were not played. Another study by Higuchi and colleagues, however, found only a 2.3-minute increase in sleep latency after a 2 hour and 45 minute videogame experience relative to the control condition. A 2.3-minute increase in sleep latency is not considered significant enough to have an important impact on the sleep of adolescents. A major limitation of the second study, however, was that the bedtime for all conditions was later than usual for the participants and this may have contributed to greater sleep drive that overwhelmed any stimulating effect of the videogame.

In order to address some of these problems, Weaver et al. set up a clever study design that kept the normal bedtime for the adolescents in the study. They wanted to look at both the physiological and cognitive stimulation effects that playing a video game have on sleep. To do this they set up an experimental condition that closely mirrors the videogame experience of many young (and young at heart) gamers. In the experimental group adolescents played Call of Duty 4: Modern Warfare. As anyone who has tried this game out can attest, it is a very intense "first person shooter" game with an extremely realistic combat simulation. For the control group adolescents watched the DVD of March of the Penguins. As anyone who has seen this movie knows, it is a brilliant piece of documentary film making that is a joy to watch. It is difficult, however, to overestimate the difference in the experience between these two forms of entertainment for adolescents.

The study was conducted in a sleep laboratory. Adolescents spent one night in the lab prior to the actual study in order to allow them to acclimate to the surroundings and procedures so that this atypical sleeping arrangement would not interfere with falling asleep on the study night. Cognitive alertness was measured by "alpha power" derived from EEG recordings made during the study. Physiological arousal was measured by heart rate. Sleep latency was measured by use of the EEG. Measurements were made before, during and after the activities. Participants either played the videogame or watched the movie for 50 minutes. Interestingly enough, the authors chose 50 minutes because this is the maximum length of continuous play recommended by Sony, which manufactures videogame units. (Do adolescents actually read the manufacture's recommendations?) Two weeks after this the participants returned to the sleep lab and participated in the other activity, either videogame or movie, that was different from the one they did on their first night.

The results were that the videogame experience resulted in a statistically significant but modest increase in sleep latency of 7.5 minutes as compared to the movie control condition. Four adolescents fell asleep during their activity condition. In all cases the activity was the movie, not the game. Neither the videogame nor the movie significantly affected physiological arousal but the videogame did mildly increase cognitive alertness.

This study indicates that pre-sleep videogame playing may affect adolescents' sleep but perhaps to a lesser degree than we tend to think based on anecdotal evidence. The study did have a number of limitations that will require further research to fully understand the impact of videogames on sleep. First, only boys were studied, as the research design did not allow for consideration of the effects of hormones on girls' sleep (either the monthly cycle or contraceptives). Second, the game playing time was probably fairly limited compared to what real world game playing often is. Third, the regular bedtime was kept, rather than allowing game players to stay up as late as they might at home. Fourth, the average age of the teens in this study was 16 years, 7 months, a bit older than the children in the picture above. Older teens may react differently to the videogame experience than younger teens. Fifth, and perhaps most importantly, participants in this study did not have significant sleep problems. The study leaves unaddressed the possible impact of late night game playing on adolescents who are developing sleep disorders such as insomnia and delayed sleep phase disorder.

The conclusions that can be drawn to date are that nighttime videogame playing, as compared to other, less arousing activities, does lead to increased cognitive arousal and to a somewhat longer time to fall asleep. This applies to older teens that keep a relatively normal bedtime and do not have other sleep problems. For these teens moderate, nighttime videogame playing does not seem to be a major concern. So parents should help their teens limit their game playing to a reasonable amount of time, and to go to bed at a reasonable time. For teens with significant sleep difficulties, however, videogames may represent a greater concern. But Grand Theft Auto does not necessarily steal a teen's sleep!