This is a follow-up to the post Shocking Research: Kids Who Play Games, Watch TV, Text Donâ€™t Read And Do Poorly At School. The original New York Times article quoted the study reviewed today.
The paper is “Impact of Singular Excessive Computer Game and Television Exposure on Sleep Patterns and Memory Performance of School-aged Children” by Markus Dworak and others (DOI: 10.1542/peds.2007-0476). The Times said of this work:
In an experiment at the German Sport University in Cologne in 2007, boys from 12 to 14 spent an hour each night playing video games after they finished homework.
On alternate nights, the boys spent an hour watching an exciting movie, like “Harry Potter” or “Star Trek,” rather than playing video games…The researchers looked at how the use of these media affected the boys’ brainwave patterns while sleeping and their ability to remember their homework in the subsequent days. They found that playing video games led to markedly lower sleep quality than watching TV, and also led to a “significant decline” in the boys’ ability to remember vocabulary words…
Markus Dworak, a researcher who led the study and is now a neuroscientist at Harvard, said it was not clear whether the boys’ learning suffered because sleep was disrupted or, as he speculates, also because the intensity of the game experience overrode the brain’s recording of the vocabulary.
“When you look at vocabulary and look at huge stimulus after that, your brain has to decide which information to store,” he said. “Your brain might favor the emotionally stimulating information over the vocabulary.”
Sound impressive and suitably scientific? Let’s see what they did. They contacted 3,580 kids to ask them to participate in their study. They heard back from 1,321. However, for various reasons, they could only coerce 11—eleven, that’s not a typo—boys into playing along. And it got worse: “Because 1 of the children was dyslexic, only the tests and polysommographs of the 10 healthy participants were analyzed.”
Stated plainly: the study results are from 10 German kids (a response rate of one quarter of one percent).
They wired the boys to polysommographs, devices which, with error, measure various “stages” of sleep, which in the study are called “Stage 1”, “Stage 2”, “Stage 3”, “Stage 4”, and “REM”. So there. They also gave the boys a pop quiz, based on a kind of video game (they had to recall maps flashed on a screen).
The 10 boys had three kids of stimuli: sitting quietly doing homework (“basal condition”), playing a shoot-’em-up video game, or watching Harry Potter or some other similar movie. The time to get to each stage of sleep, total time of sleep, and performance on the pop quiz was measured after each stimulus. Actually, they measured the time in minutes to each stage, and then, to double the amount of measurements and increase the chance of finding a small p-value, they also measured the difference in time between each stage.
Results? It took “10.83” minutes to reach Stage 1 sleep after sitting quietly, “32.50” minutes after playing a game, and “24.61” minutes after watching a movie. This difference gave a publishable p-value. I put the numbers in quotes because I desire to be as exacting as our authors and write the times to the nearest one-hundredth of a minute. One-hundredth of a minute! That’s about a half a second.
Yes, the differences in times to various stages of sleep were measured to within half a second. In real, and not in scientific, life nobody would care about differences in sleep less than an hour. But since we are being scientific, we can care about a lot less.
The boys also performed worse on the pop quiz after playing games or watching television. The authors don’t give us the raw numbers here, just the percent difference from some pre- to some post-quiz. So we cannot be sure if these differences are meaningful or just scientific.
The conclusion in their words:
Our data indicate that excessive media consumption, especially computer game playing, impairs sleep patterns and verbal cognitive performance in children. Because children’s sleep-related problems seem to be highly persistent; prevalent; and associated with somatic complaints, psychiatric symptoms, especially behavioral and emotional symptoms, attention problems such as hyperactivity, and scholastic problems, they constitute a considerable and growing health problem among children and therefore should receive more attention [i.e., more funding for them].
The conclusion in my words:
Kids who jump into bed right after playing video games or watching television take fifteen to twenty minutes longer to fall asleep than kids who sit quietly doing homework. To avoid excessive sleeplessness, psychiatric disorders, and other societal difficulties, parents should yell up the stairs, “Don’t make me come up there!” to ensure kids go to bed on time.