How much screen time should I leave to my child? – Quartz

What would an optimal 24-hour day look like for children? According to the Canadian 24-Hour Movement Guidelines for Children and Youth, for children aged 8 to 11, it should include at least 60 minutes of physical activity, two hours or less of free time, and nine at 11 o'clock to sleep. Yet, in a new study, only one in 20 American children has satisfied these three recommendations.

The research, published Thursday (Sept. 27) in the academic journal Lancet Child & Adolescent Health (paywall), used data from the ABCD (Adolescent Brain Cognitive Development) study, a 10-year longitudinal observational study performed on 10 years. between eight and eleven years old, from 21 study sites in the United States, and compared their daily exercises, their technology, and their sleep patterns to the guidelines. The researchers then assessed participants' "overall cognition" with standards developed by the National Institute of Health.

They found that only 5% of children responded to all three recommendations. Sixty-three percent of children spent more than two hours a day watching screens and exceeding the time limit; 82% of children did not follow the daily physical activity guidelines; and 49% did not get the recommended sleep hours. Twenty-nine percent did not meet any of the recommended standards.

The rare few who met all three criteria performed better on cognition, language and memory tests than children who did not respond to any of the recommendations. The study also found that, of the three recommendations, screen time guidelines appeared to be the most correlated with higher mental performance: as long as children respected the recommendation regarding time spent in front of the screen. screen, they exceeded the others.

Respect for sleep recommendations, on the other hand, was significantly correlated with higher cognition scores, but seemed much less important than time spent in front of a screen.

On the other hand, the effect of physical activity on child cognition was statistically insignificant in this study. Researchers say this is likely because respondents completed a self-report questionnaire, which means that the study was not able to distinguish between intensity or type of physical activity. Lead author Jeremy Walsh says the ABCD study authors plan to measure physical activity using a FitBit in the next cohort of participants to compensate for this problem.

The authors write that their findings "underscore the importance of limiting the time spent in front of the screen and encouraging healthy sleep to improve cognition in children." early childhood (before the age of five) and in adolescence (after the onset of puberty, when the human brain is particularly vulnerable to psychiatric illness). As Jenny Anderson wrote for Quartz:

The excessive use of technology can cause stress in the brain, which has two negative effects. First of all, more stress causes the brain to release cortisol, which can kill neurons in the brain's memory center (the hippocampus). Second, stress can inactivate the prefrontal cortex of the brain or the "executive" part of the brain, which normally limits dopamine and our sense of pleasure or reward. When the brain gets used to a higher level of dopamine, he wants us to continue to look for the addictive substance or habit.

The last Lancet study has several limitations, the main one being that the correlation is not causal. And, as experts have said of the impact of technology on children, more research is needed to determine what types of screen activities affect children and to what extent. But what is certain, as Hamza Shaban writes in the Washington Post, is that "parents who are willing to separate their children from their smartphones can help the children of their children."